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Sample records for octopus wunderpus photogenicus

  1. Individually unique body color patterns in octopus (Wunderpus photogenicus) allow for photoidentification.

    PubMed

    Huffard, Christine L; Caldwell, Roy L; DeLoach, Ned; Gentry, David Wayne; Humann, Paul; MacDonald, Bill; Moore, Bruce; Ross, Richard; Uno, Takako; Wong, Stephen

    2008-01-01

    Studies on the longevity and migration patterns of wild animals rely heavily on the ability to track individual adults. Non-extractive sampling methods are particularly important when monitoring animals that are commercially important to ecotourism, and/or are rare. The use of unique body patterns to recognize and track individual vertebrates is well-established, but not common in ecological studies of invertebrates. Here we provide a method for identifying individual Wunderpus photogenicus using unique body color patterns. This charismatic tropical octopus is commercially important to the underwater photography, dive tourism, and home aquarium trades, but is yet to be monitored in the wild. Among the adults examined closely, the configurations of fixed white markings on the dorsal mantle were found to be unique. In two animals kept in aquaria, these fixed markings were found not to change over time. We believe another individual was photographed twice in the wild, two months apart. When presented with multiple images of W. photogenicus, volunteer observers reliably matched photographs of the same individuals. Given the popularity of W. photogenicus among underwater photographers, and the ease with which volunteers can correctly identify individuals, photo-identification appears to be a practical means to monitor individuals in the wild.

  2. Individually Unique Body Color Patterns in Octopus (Wunderpus photogenicus) Allow for Photoidentification

    PubMed Central

    Huffard, Christine L.; Caldwell, Roy L.; DeLoach, Ned; Gentry, David Wayne; Humann, Paul; MacDonald, Bill; Moore, Bruce; Ross, Richard; Uno, Takako; Wong, Stephen

    2008-01-01

    Studies on the longevity and migration patterns of wild animals rely heavily on the ability to track individual adults. Non-extractive sampling methods are particularly important when monitoring animals that are commercially important to ecotourism, and/or are rare. The use of unique body patterns to recognize and track individual vertebrates is well-established, but not common in ecological studies of invertebrates. Here we provide a method for identifying individual Wunderpus photogenicus using unique body color patterns. This charismatic tropical octopus is commercially important to the underwater photography, dive tourism, and home aquarium trades, but is yet to be monitored in the wild. Among the adults examined closely, the configurations of fixed white markings on the dorsal mantle were found to be unique. In two animals kept in aquaria, these fixed markings were found not to change over time. We believe another individual was photographed twice in the wild, two months apart. When presented with multiple images of W. photogenicus, volunteer observers reliably matched photographs of the same individuals. Given the popularity of W. photogenicus among underwater photographers, and the ease with which volunteers can correctly identify individuals, photo-identification appears to be a practical means to monitor individuals in the wild. PMID:19009019

  3. Octopus

    SciTech Connect

    Strubbe, David

    2015-05-26

    Octopus is a scientific program aimed at the ab initio virtual experimentation on a hopefully ever-increasing range of system types. Electrons are described quantum-mechanically within density-functional theory (DFT), in its time-dependent form (TDDFT) when doing simulations in time. Nuclei are described classically as point particles. Electron-nucleus interaction is described within the pseudopotential approximation.

  4. Octopus

    SciTech Connect

    Strubbe, David

    2015-05-26

    Octopus is a scientific program aimed at the ab initio virtual experimentation on a hopefully ever-increasing range of system types. Electrons are described quantum-mechanically within density-functional theory (DFT), in its time-dependent form (TDDFT) when doing simulations in time. Nuclei are described classically as point particles. Electron-nucleus interaction is described within the pseudopotential approximation.

  5. Experimental evidence for spatial learning on octopuses (octopus bimaculoides).

    PubMed

    Boal, J G; Dunham, A W; Williams, K T; Hanlon, R T

    2000-09-01

    Octopuses forage far from temporary home dens to which they return for shelter. Spatial tasks may assess learning. Octopuses (Octopus bimaculoides) were placed in a novel arena, and their movements were tracked for 72 hr. Movements around the arena decreased across time, consistent with exploratory learning. Next, octopuses were given 23 hr to move around an arena; after a 24-hr delay, their memory of a burrow location was tested. Most remembered the location of the open burrow, demonstrating learning in 1 day. Finally, octopuses were trained to locate a single open escape burrow among 6 possible locations. Retention was tested after a week and was immediately followed by reversal training (location rotated 180 degrees ). Octopuses learned the original location of the burrow, remembering it for a week. Path lengths increased significantly after reversal, gradually improving and showing relearning. Octopuses show exploratory behavior, learning, and retention of spatial information.

  6. The toxicology of Octopus maculosa: the blue-ringed octopus.

    PubMed

    Bonnet, M S

    1999-10-01

    The biotoxicology of the Australian blue-ringed octopus is detailed with the view of introducing it as a remedy into the homoeopathic Materia Medica and stimulating the second step of proving this venom.

  7. Tissue channel morphology in Octopus.

    PubMed

    Browning, J; Casley-Smith, J R

    1981-01-01

    The morphology of tissue channels in muscle and neural tissues of Octopus was investigated, at the ultrastructural level, with a technique involving the precipitation of ferrocyanide ions. The numbers, sizes and conductivities of the channels were estimated from quantitative data. No evidence was gained to indicate that the low microvascular density in Octopus is coupled to an especially extensive network of extravascular channels. The tissue channel system in Octopus appears to be broadly comparable with the mammalian system; a lack of information prevents more appropriate comparisons with marine fishes. Probable functions of tissue channels in Octopus and mammals, and reasons for apparent similarities and differences in the channel organization of these divergent groups, are discussed.

  8. Signal Use by Octopuses in Agonistic Interactions.

    PubMed

    Scheel, David; Godfrey-Smith, Peter; Lawrence, Matthew

    2016-02-08

    Cephalopods show behavioral parallels to birds and mammals despite considerable evolutionary distance [1, 2]. Many cephalopods produce complex body patterns and visual signals, documented especially in cuttlefish and squid, where they are used both in camouflage and a range of interspecific interactions [1, 3-5]. Octopuses, in contrast, are usually seen as solitary and asocial [6, 7]; their body patterns and color changes have primarily been interpreted as camouflage and anti-predator tactics [8-12], though the familiar view of the solitary octopus faces a growing list of exceptions. Here, we show by field observation that in a shallow-water octopus, Octopus tetricus, a range of visible displays are produced during agonistic interactions, and these displays correlate with the outcome of those interactions. Interactions in which dark body color by an approaching octopus was matched by similar color in the reacting octopus were more likely to escalate to grappling. Darkness in an approaching octopus met by paler color in the reacting octopus accompanied retreat of the paler octopus. Octopuses also displayed on high ground and stood with spread web and elevated mantle, often producing these behaviors in combinations. This study is the first to document the systematic use of signals during agonistic interactions among octopuses. We show prima facie conformity of our results to an influential model of agonistic signaling [13]. These results suggest that interactions have a greater influence on octopus evolution than has been recognized and show the importance of convergent evolution in behavioral traits.

  9. Early temperamental traits in an octopus (Octopus bimaculoides).

    PubMed

    Sinn, D L; Perrin, N A; Mather, J A; Anderson, R C

    2001-12-01

    During their 3rd week of life, 73 Octopus bimaculoides were observed to test whether discrete behaviors could be grouped reliably to reflect dimensions of temperament. Frequencies of behaviors during Week 3 were subjected to principal-components analysis (PCA), resulting in 4 components (active engagement, arousal/readiness, aggression, and avoidance/disinterest) that explain 53% of the variance. Levels of temperamental traits were then evaluated for 37 octopuses using composite scores at 3 time points across the first 9 weeks of life. Profile analysis revealed significant change for the testing group as a whole in trait expression levels from Week 3 to Week 6. Results also suggest a significant effect of relatedness on developing temperamental profiles of octopuses. Discussion focuses on how results apply to the life history of O. bimaculoides and what temperament can reveal about adaptive individuality in a protostome.

  10. Interspecific evaluation of octopus escape behavior.

    PubMed

    Wood, James B; Anderson, Roland C

    2004-01-01

    The well-known ability of octopuses to escape enclosures is a behavior that can be fatal and, therefore, is an animal welfare issue. This study obtained survey data from 38 participants-primarily scientists and public aquarists who work with octopuses-on 25 described species of octopus. The study demonstrates that the likeliness to escape is species specific (p =.001). The study gives husbandry techniques to keep captive octopuses contained. This first interspecific study of octopus escape behavior allows readers to make informed species-specific husbandry choices.

  11. Contrasting activity patterns of two related octopus species, Octopus macropus and Octopus vulgaris.

    PubMed

    Meisel, Daniela V; Byrne, Ruth A; Kuba, Michael; Mather, Jennifer; Ploberger, Werner; Reschenhofer, Erhard

    2006-08-01

    Octopus macropus and Octopus vulgaris have overlapping habitats and are exposed to similar temporal changes. Whereas the former species is described as nocturnal in the field, there are conflicting reports about the activity time of the latter one. To compare activity patterns, the authors tested both species in the laboratory. Octopuses were exposed to a light-dark cycle and held under constant dim light for 7 days each. O. macropus showed nocturnal and light-cued activity. According to casual observations, O. vulgaris started out nocturnal but had switched to mostly diurnal when the experiment began. Individual variation of its activity was found. The different activity patterns of O. macropus and O. vulgaris might reflect their lifestyles, the latter species being more generalist.

  12. Octopuses (Enteroctopus dofleini) recognize individual humans.

    PubMed

    Anderson, Roland C; Mather, Jennifer A; Monette, Mathieu Q; Zimsen, Stephanie R M

    2010-01-01

    This study exposed 8 Enteroctopus dofleini separately to 2 unfamiliar individual humans over a 2-week period under differing circumstances. One person consistently fed the octopuses and the other touched them with a bristly stick. Each human recorded octopus body patterns, behaviors, and respiration rates directly after each treatment. At the end of 2 weeks, a body pattern (a dark Eyebar) and 2 behaviors (reaching arms toward or away from the tester and funnel direction) were significantly different in response to the 2 humans. The respiration rate of the 4 larger octopuses changed significantly in response to the 2 treatments; however, there was no significant difference in the 4 smaller octopuses' respiration. Octopuses' ability to recognize humans enlarges our knowledge of the perceptual ability of this nonhuman animal, which depends heavily on learning in response to visual information. Any training paradigm should take such individual recognition into consideration as it could significantly alter the octopuses' responses.

  13. Underwater bipedal locomotion by octopuses in disguise.

    PubMed

    Huffard, Christine L; Boneka, Farnis; Full, Robert J

    2005-03-25

    Here we report bipedal movement with a hydrostatic skeleton. Two species of octopus walk on two alternating arms using a rolling gait and appear to use the remaining six arms for camouflage. Octopus marginatus resembles a coconut, and Octopus (Abdopus) aculeatus, a clump of floating algae. Using underwater video, we analyzed the kinematics of their strides. Each arm was on the sand for more than half of the stride, qualifying this behavior as a form of walking.

  14. Octopus movement: push right, go left.

    PubMed

    Hooper, Scott L

    2015-05-04

    Octopus arms have essentially infinite degrees of freedom. New research shows that, despite this potentially great complexity, to locomote octopuses simply elongate one or more arms, thus pushing the body in the opposite direction, and do so without activating the arms in an ordered pattern.

  15. Does Octopus vulgaris have preferred arms?

    PubMed

    Byrne, Ruth A; Kuba, Michael J; Meisel, Daniela V; Griebel, Ulrike; Mather, Jennifer A

    2006-08-01

    Previous behavioral studies in Octopus vulgaris revealed lateralization of eye use. In this study, the authors expanded the scope to investigate arm preferences. The octopus's generalist hunting lifestyle and the structure of their arms suggest that these animals have no need to designate specific arms for specific tasks. However, octopuses also show behaviors, like exploration, in which only single or small groups of arms are involved. Here the authors show that octopuses had a strong preference for anterior arm use to reach for and explore objects, which points toward a task division between anterior and posterior arms. Four out of 8 subjects also showed a lateral bias. In addition, octopuses had a preference for a specific arm to reach into a T maze to retrieve a food reward. These findings give evidence for limb-specialization in an animal whose 8 arms were believed to be equipotential.

  16. Characterization of microsatellite loci from two-spotted octopus Octopus bimaculatus Verrill 1883 from pyrosequencing reads

    USGS Publications Warehouse

    Domínguez-Contreras, J. F.; Munguía-Vega, A.; Ceballos-Vázquez, B. P.; Arellano-Martínez, M.; Culver, Melanie

    2014-01-01

    We characterized 22 novel microsatellite loci in the two-spotted octopus Octopus bimaculatus using 454 pyrosequencing reads. All loci were polymorphic and will be used in studies of marine connectivity aimed at increasing sustainability of the resource. The mean number alleles per locus was 13.09 (range 7–19) and observed heterozygosities ranged from 0.50 to 1.00. Four loci pairs were linked and three deviated from Hardy–Weinberg equilibrium. Eighteen and 12 loci were polymorphic in Octopus bimaculoides and Octopus hubbsorum, respectively.

  17. Infrared studies of octopus rhodopsin and lumirhodopsin

    NASA Astrophysics Data System (ADS)

    Masuda, Satoshi; Morita, Eugene H.; Tasumi, Mitsuo; Iwasa, Tatsuo; Tsuda, Motoyuki

    1993-08-01

    The infrared difference spectra between octopus rhodopsin and lumirhodopsin have been observed at 210 K under irradiation of blue and orange light under neutral conditions. The CN stretching frequencies of the protonated Schiff-base linkage shift upon H/D exchange. The H/D shifts observed in this study for octopus rhodopsin and lumirhodopsin are 25 and 23 cm -1, respectively, whereas those for bovine rhodopsin and lumirhodopsin have been reported to be about 30 and 4cm -1, respectively. These results indicate that environments around the Schiff-base linkage differ between octopus and bovine lumirhodopsin, whereas those of octopus rhodopsin and lumirhodopsin are similar. The relationship between the H/D shift of the CN stretching band and the hydrogen bond involving the protonated Schiff base is discussed.

  18. Cannibalistic behavior of octopus (Octopus vulgaris) in the wild.

    PubMed

    Hernández-Urcera, Jorge; Garci, Manuel E; Roura, Alvaro; González, Angel F; Cabanellas-Reboredo, Miguel; Morales-Nin, Beatriz; Guerra, Angel

    2014-11-01

    The first description of cannibalism in wild adult Octopus vulgaris is presented from 3 observations made in the Ría de Vigo (NW Spain), which were filmed by scuba divers. These records document common traits in cannibalistic behavior: (a) it was intercohort cannibalism; (b) attacks were made by both males and females; (c) in 2 of the records, the prey were transported to the den, which was covered with stones of different sizes; (d) the predator started to eat the tip of the arms of its prey; (e) predation on conspecifics occurred even if there were other abundant prey available (i.e., mussels); and (f) the prey/predator weight ratio in the 3 cases ranged from 20% to 25% body weight. The relationships between this behavior and sex, defense of territory, energy balance, food shortage, competition and predation, as well as how the attacker kills its victim are discussed.

  19. Connecting your Apple to Octopus 7600's

    SciTech Connect

    Barton, G.W. Jr.

    1983-01-17

    In UCID-19588, Communicating between the Apple and the Wang, we described how to take Apple DOS text files and send them to the Wang, and how to return Wang files to the Apple. It is also possible to use your Apple as an Octopus terminal, and to exchange files with Octopus 7600's. Presumably, you can also talk to the Crays, or any other part of the system. This connection has another virtue. It eliminates one of the terminals in your office.

  20. Appetitive conditioning in Octopus cyanea.

    PubMed

    Papini, M R; Bitterman, M E

    1991-06-01

    The performance of Octopus cyanea was studied in 3 appetitive conditioning situations. In Experiment 1, 2 groups were trained in a runway; a large reward produced faster acquisition when reinforcement was consistent and better subsequent performance on a partial schedule than did a small reward. In Experiment 2, activity in the vicinity of a feeder was measured, and in Experiment 3, latency and probability of response were measured in an automated version of a traditional conditioned attack situation (Boycott & Young, 1950). There was evidence of acquisition with continuous reinforcement in both experiments but in neither with partial reinforcement. All of the results can be understood in terms of growth and decline in the strength of stimulus-reinforcer associations with reinforcement and nonreinforcement.

  1. Reproductive traits of the small Patagonian octopus Octopus tehuelchus

    NASA Astrophysics Data System (ADS)

    Storero, Lorena P.; Narvarte, Maite A.; González, Raúl A.

    2012-12-01

    This study evaluated the reproductive features of Octopus tehuelchus in three coastal environments of San Matías Gulf (Patagonia). Monthly samples of O. tehuelchus were used to estimate size at maturity, compare seasonal changes in oocyte size frequency distributions between sites as well as oocyte number and size between female maturity stage and sites. Females in Islote Lobos had a smaller size at maturity than females in San Antonio Bay and El Fuerte, probably as a consequence of a generally smaller body size. Males in San Antonio Bay were smaller at maturity than females. O. tehuelchus is a simultaneous terminal spawner. Fecundity (expressed as number of vitellogenic oocytes in ovary) was lower in Islote Lobos, and an increase in oocyte number in relation to female total weight was found. Females in San Antonio Bay had the largest oocytes, which may indicate higher energy reserves for the embryo and therefore higher juvenile survival. There was a close relationship between reproduction, growth and condition, represented as size at maturity, number and size of vitellogenic oocytes and period of maturity and spawning. Given the local variation in some reproductive features of O. tehuelchus, studies should focus on the environmental factors, which bring about this variation, and on how it affects the dynamics of local populations.

  2. Extraintestinal gamogony of Aggregata octopiana in the reared common octopus (Octopus vulgaris) (Cephalopoda: Octopodidae).

    PubMed

    Mladineo, Ivona; Bocina, Ivana

    2007-11-01

    Aggregata octopiana (Apicomplexa, Aggregatidae) is the most prevalent coccidian in the wild common octopus (Octopus vulgaris), whose heteroxenous life cycle includes gamogony and sporogony undergoing in the octopus digestive tract. In the infected reared octopi, we observed an unusual extraintestinal distribution of the coccidian, with both gamogony and sporogony ongoing in dermal and gill tissue. Oocysts and macrogamonts were embedded in the dermal connective tissue of octopian arms, demarcated by a thin cyst wall or multilayered dark membrane. In gill connective and epithelial tissue all developmental stages were observed, eliciting hemocytic infiltration. Sometimes a complete substitution of the tissue by cysts and developmental stages occurred, resulting in necrosis of gill tissue.

  3. An embodied view of octopus neurobiology.

    PubMed

    Hochner, Binyamin

    2012-10-23

    Octopuses have a unique flexible body and unusual morphology, but nevertheless they are undoubtedly a great evolutionary success. They compete successfully with vertebrates in their ecological niche using a rich behavioral repertoire more typical of an intelligent predator which includes extremely effective defensive behavior--fast escape swimming and an astonishing ability to adapt their shape and color to their environment. The most obvious characteristic feature of an octopus is its eight long and flexible arms, but these pose a great challenge for achieving the level of motor and sensory information processing necessary for their behaviors. First, coordinating motion is a formidable task because of the infinite degrees of freedom that have to be controlled; and second, it is hard to use body coordinates in this flexible animal to represent sensory information in a central control system. Here I will review experimental results suggesting that these difficulties, arising from the animal's morphology, have imposed the evolution of unique brain/body/behavior relationships best explained as intelligent behavior which emerges from the octopus's embodied organization. The term 'intelligent embodiment' comes from robotics and refers to an approach to designing autonomous robots in which the behavior emerges from the dynamic physical and sensory interactions of the agent's materials, morphology and environment. Consideration of the unusual neurobiology of the octopus in the light of its unique morphology suggests that similar embodied principles are instrumental for understanding the emergence of intelligent behavior in all biological systems.

  4. Design of a biomimetic robotic octopus arm.

    PubMed

    Laschi, C; Mazzolai, B; Mattoli, V; Cianchetti, M; Dario, P

    2009-03-01

    This paper reports the rationale and design of a robotic arm, as inspired by an octopus arm. The octopus arm shows peculiar features, such as the ability to bend in all directions, to produce fast elongations, and to vary its stiffness. The octopus achieves these unique motor skills, thanks to its peculiar muscular structure, named muscular hydrostat. Different muscles arranged on orthogonal planes generate an antagonistic action on each other in the muscular hydrostat, which does not change its volume during muscle contractions, and allow bending and elongation of the arm and stiffness variation. By drawing inspiration from natural skills of octopus, and by analysing the geometry and mechanics of the muscular structure of its arm, we propose the design of a robot arm consisting of an artificial muscular hydrostat structure, which is completely soft and compliant, but also able to stiffen. In this paper, we discuss the design criteria of the robotic arm and how this design and the special arrangement of its muscular structure may bring the building of a robotic arm into being, by showing the results obtained by mathematical models and prototypical mock-ups.

  5. Intramantle inking: a stress behavior in Octopus bimaculoides (Mollusca: Cephalopoda).

    PubMed

    Bennett, Heather; Toll, Ronald B

    2011-11-01

    Several Pacific 2-spot octopuses (Octopus bimaculoides) shipped from California and held in a recirculating seawater system at Illinois College exhibited an unusual postshipping stress behavior not previously documented in the literature. Ink, normally ejected into the surrounding seawater, was uncharacteristically retained in the mantle cavity. We describe the resulting behaviors, discuss successful resuscitation efforts, and briefly consider the possible role(s) that ink may have played in the death of one octopus.

  6. Intramantle Inking: A Stress Behavior in Octopus bimaculoides (Mollusca: Cephalopoda)

    PubMed Central

    Toll, Ronald B

    2011-01-01

    Several Pacific 2-spot octopuses (Octopus bimaculoides) shipped from California and held in a recirculating seawater system at Illinois College exhibited an unusual postshipping stress behavior not previously documented in the literature. Ink, normally ejected into the surrounding seawater, was uncharacteristically retained in the mantle cavity. We describe the resulting behaviors, discuss successful resuscitation efforts, and briefly consider the possible role(s) that ink may have played in the death of one octopus. PMID:22330791

  7. Scopolamine impairs memory recall in Octopus vulgaris.

    PubMed

    Fiorito, G; Agnisola, C; d'Addio, M; Valanzano, A; Calamandrei, G

    1998-09-04

    The involvement of the central cholinergic system in predatory performance, and on the recall of individual and observational memory in Octopus vulgaris was studied by treating the animals with the muscarinic antagonist scopolamine (2 mg/kg). The absence of the effects of the injection of scopolamine on blood circulation was also checked. Scopolamine did not affect the ability of octopuses to prey on live crabs. However, it interfered significantly with memory recall. In fact, the ability to solve the jar problem was impaired within the first hour after injection (short-term effects) and was only partially recovered after 24 h (long-term). Moreover, both individual and observational learning of a visual discrimination were significantly reduced at the short- and long-term testing. These results support a role of the cholinergic system in the processes of memory recall of O. vulgaris.

  8. Death in the octopus' garden: fatal blue-lined octopus envenomations of adult green sea turtles.

    PubMed

    Townsend, Kathy A; Altvater, Jens; Thomas, Michael C; Schuyler, Qamar A; Nette, Geoffrey W

    2012-01-01

    The blue-lined octopus Hapalochlaena fasciata contains the powerful neuromuscular blocker tetrodotoxin (TTX), which causes muscle weakness and respiratory failure. H. fasciata is regarded as one of the most venomous marine animals in the world, and multiple human fatalities have been attributed to the octopus. To date, there have been no recorded incidents of an envenomation of a wild animal. Here, we present a newly developed, multi-stage tandem mass spectrometry technique that provides unequivocal evidence for two cases of envenomation of two ~110 kg herbivorous green sea turtles by two tiny cryptic blue-lined octopuses (~4 cm body length). These cases of accidental ingestion provide evidence for the first time of the antipredator effect of TTX and highlight a previously unconsidered threat to turtles grazing within seagrass beds.

  9. Octopuses (Octopus bimaculoides) and cuttlefishes (Sepia pharaonis, S. officinalis) can conditionally discriminate.

    PubMed

    Hvorecny, Lauren M; Grudowski, Jessica L; Blakeslee, Carrie J; Simmons, Tiffany L; Roy, Paula R; Brooks, Jennifer A; Hanner, Rachel M; Beigel, Marie E; Karson, Miranda A; Nichols, Rachel H; Holm, Johanna B; Boal, Jean Geary

    2007-10-01

    In complex navigation using landmarks, an animal must discriminate between potential cues and show context (condition) sensitivity. Such conditional discrimination is considered a form of complex learning and has been associated primarily with vertebrates. We tested the hypothesis that octopuses and cuttlefish are capable of conditional discrimination. Subjects were trained in two maze configurations (the conditions) in which they were required to select one of two particular escape routes within each maze (the discrimination). Conditional discrimination could be demonstrated by selecting the correct escape route in each maze. Six of ten mud-flat octopuses (Octopus bimaculoides), 6 of 13 pharaoh cuttlefish (Sepia pharaonis), and one of four common cuttlefish (S. officinalis) demonstrated conditional discrimination by successfully solving both mazes. These experiments demonstrate that cephalopods are capable of conditional discrimination and extend the limits of invertebrate complex learning.

  10. Reconsideration of Serial Visual Reversal Learning in Octopus (Octopus vulgaris) from a Methodological Perspective

    PubMed Central

    Bublitz, Alexander; Weinhold, Severine R.; Strobel, Sophia; Dehnhardt, Guido; Hanke, Frederike D.

    2017-01-01

    Octopuses (Octopus vulgaris) are generally considered to possess extraordinary cognitive abilities including the ability to successfully perform in a serial reversal learning task. During reversal learning, an animal is presented with a discrimination problem and after reaching a learning criterion, the signs of the stimuli are reversed: the former positive becomes the negative stimulus and vice versa. If an animal improves its performance over reversals, it is ascribed advanced cognitive abilities. Reversal learning has been tested in octopus in a number of studies. However, the experimental procedures adopted in these studies involved pre-training on the new positive stimulus after a reversal, strong negative reinforcement or might have enabled secondary cueing by the experimenter. These procedures could have all affected the outcome of reversal learning. Thus, in this study, serial visual reversal learning was revisited in octopus. We trained four common octopuses (O. vulgaris) to discriminate between 2-dimensional stimuli presented on a monitor in a simultaneous visual discrimination task and reversed the signs of the stimuli each time the animals reached the learning criterion of ≥80% in two consecutive sessions. The animals were trained using operant conditioning techniques including a secondary reinforcer, a rod that was pushed up and down the feeding tube, which signaled the correctness of a response and preceded the subsequent primary reinforcement of food. The experimental protocol did not involve negative reinforcement. One animal completed four reversals and showed progressive improvement, i.e., it decreased its errors to criterion the more reversals it experienced. This animal developed a generalized response strategy. In contrast, another animal completed only one reversal, whereas two animals did not learn to reverse during the first reversal. In conclusion, some octopus individuals can learn to reverse in a visual task demonstrating behavioral

  11. Neuroethology: self-recognition helps octopuses avoid entanglement.

    PubMed

    Crook, Robyn J; Walters, Edgar T

    2014-06-02

    How an octopus performs complex movements of its eight sucker-studded arms without entanglement has been a mystery. A new study has found that self-recognition of the octopus's skin by its suckers inhibits reflexive grasping of its own arms, simplifying the mechanisms needed to generate intricate arm behavior.

  12. Metal accumulation and oxidative stress biomarkers in octopus (Octopus vulgaris) from Northwest Atlantic.

    PubMed

    Semedo, Miguel; Reis-Henriques, Maria Armanda; Rey-Salgueiro, Ledicia; Oliveira, Marta; Delerue-Matos, Cristina; Morais, Simone; Ferreira, Marta

    2012-09-01

    Metals are ubiquitous in the environment and accumulate in aquatic organisms and are known for their ability to enhance the production of reactive oxygen species (ROS). In aquatic species, oxidative stress mechanisms have been studied by measuring antioxidant enzyme activities and oxidative damages in tissues. The aim of this study was to apply and validate a set of oxidative stress biomarkers and correlate responses with metal contents in tissues of common octopus (Octopus vulgaris). Antioxidant enzyme activity (catalase--CAT, superoxide dismutase--SOD and glutathione S-transferases--GST), oxidative damages (lipid peroxidation--LPO and protein carbonyl content--PCO) and metal content (Cu, Zn, Pb, Cd and As) in the digestive gland and arm of octopus, collected in the NW Portuguese coast in different periods, were assessed after capture and after 14 days in captivity. CAT and SOD activities were highly responsive to fluctuations in metal concentrations and able to reduce oxidative damage, LPO and PCO in the digestive gland. CAT activity was also positively correlated with SOD and GST activities, which emphasizes that the three enzymes respond in a coordinated way to metal induced oxidative stress. Our results validate the use of oxidative stress biomarkers to assess metal pollution effects in this ecological and commercial relevant species. Moreover, octopus seems to have the ability to control oxidative damage by triggering an antioxidant enzyme coordinated response in the digestive gland.

  13. Dynamic model of the octopus arm. I. Biomechanics of the octopus reaching movement.

    PubMed

    Yekutieli, Yoram; Sagiv-Zohar, Roni; Aharonov, Ranit; Engel, Yaakov; Hochner, Binyamin; Flash, Tamar

    2005-08-01

    The octopus arm requires special motor control schemes because it consists almost entirely of muscles and lacks a rigid skeletal support. Here we present a 2D dynamic model of the octopus arm to explore possible strategies of movement control in this muscular hydrostat. The arm is modeled as a multisegment structure, each segment containing longitudinal and transverse muscles and maintaining a constant volume, a prominent feature of muscular hydrostats. The input to the model is the degree of activation of each of its muscles. The model includes the external forces of gravity, buoyancy, and water drag forces (experimentally estimated here). It also includes the internal forces generated by the arm muscles and the forces responsible for maintaining a constant volume. Using this dynamic model to investigate the octopus reaching movement and to explore the mechanisms of bend propagation that characterize this movement, we found the following. 1) A simple command producing a wave of muscle activation moving at a constant velocity is sufficient to replicate the natural reaching movements with similar kinematic features. 2) The biomechanical mechanism that produces the reaching movement is a stiffening wave of muscle contraction that pushes a bend forward along the arm. 3) The perpendicular drag coefficient for an octopus arm is nearly 50 times larger than the tangential drag coefficient. During a reaching movement, only a small portion of the arm is oriented perpendicular to the direction of movement, thus minimizing the drag force.

  14. Uptake, transfer and elimination kinetics of paralytic shellfish toxins in common octopus (Octopus vulgaris).

    PubMed

    Lopes, Vanessa M; Baptista, Miguel; Repolho, Tiago; Rosa, Rui; Costa, Pedro Reis

    2014-01-01

    Marine phycotoxins derived from harmful algal blooms are known to be associated with mass mortalities in the higher trophic levels of marine food webs. Bivalve mollusks and planktivorous fish are the most studied vectors of marine phycotoxins. However, field surveys recently showed that cephalopod mollusks also constitute potential vectors of toxins. Thus, here we determine, for the first time, the time course of accumulation and depuration of paralytic shellfish toxins (PSTs) in the common octopus (Octopus vulgaris). Concomitantly, the underlying kinetics of toxin transfer between tissue compartments was also calculated. Naturally contaminated clams were used to orally expose the octopus to PSTs during 6 days. Afterwards, octopus specimens were fed with non-contaminated shellfish during 10 days of depuration period. Toxins reached the highest concentrations in the digestive gland surpassing the levels in the kidney by three orders of magnitude. PSTs were not detected in any other tissue analyzed. Net accumulation efficiencies of 42% for GTX5, 36% for dcSTX and 23% for C1+2 were calculated for the digestive gland. These compounds were the most abundant toxins in both digestive gland and the contaminated shellfish diet. The small differences in relative abundance of each toxin observed between the prey and the cephalopod predator indicates low conversion rates of these toxins. The depuration period was better described using an exponential decay model comprising a single compartment - the entire viscera. It is worth noting that since octopuses' excretion and depuration rates are low, the digestive gland is able to accumulate very high toxin concentrations for long periods of time. Therefore, the present study clearly shows that O. vulgaris is a high-potential vector of PSTs during and even after the occurrence of these toxic algal blooms.

  15. Neurobiology: motor control of flexible octopus arms.

    PubMed

    Sumbre, Germán; Fiorito, Graziano; Flash, Tamar; Hochner, Binyamin

    2005-02-10

    Animals with rigid skeletons can rely on several mechanisms to simplify motor control--for example, they have skeletal joints that reduce the number of variables and degrees of freedom that need to be controlled. Here we show that when the octopus uses one of its long and highly flexible arms to transfer an object from one place to another, it employs a vertebrate-like strategy, temporarily reconfiguring its arm into a stiffened, articulated, quasi-jointed structure. This indicates that an articulated limb may provide an optimal solution for achieving precise, point-to-point movements.

  16. Aggregata (Protozoa: Apicomplexa) infection in the common octopus Octopus vulgaris from the West Mediterranean Sea: The infection rates and possible effect of faunistic, environmental and ecological factors

    NASA Astrophysics Data System (ADS)

    Mayo-Hernández, E.; Barcala, E.; Berriatua, E.; García-Ayala, A.; Muñoz, P.

    2013-10-01

    Prevalence and distribution of the coccidian parasite Aggregata octopiana (Protozoa: Apicomplexa) in common octopus (Octopus vulgaris) in the Mediterranean Spanish coasts were studied. A total of 114 octopuses were sampled from 30 geographic sectors by trawl fleet, and whitish macroscopic oocysts typical of A. octopiana infection were recorded in 96% of octopuses in the digestive tract and mainly in intestine and spiral caecum. The univariate analysis showed that lesion extension varied according to specific octopus, environmental and faunistic variables. A subsequent multivariable analysis indicated that the risk of macroscopic lesions in the caecum was greater in males compared to females, in octopuses living in deeper compared to shallower waters and in hauls where the crustacean Pagurus excavatus was present. The study provides further evidence of the abundance of A. octopiana in octopus ecosystems urging for further studies to evaluate its health impact. The combined abundance of infected octopuses and P. excavatus merits attention.

  17. Allopatric speciation within a cryptic species complex of Australasian octopuses.

    PubMed

    Amor, Michael D; Norman, Mark D; Cameron, Hayley E; Strugnell, Jan M

    2014-01-01

    Despite extensive revisions over recent decades, the taxonomy of benthic octopuses (Family Octopodidae) remains in a considerable flux. Among groups of unresolved status is a species complex of morphologically similar shallow-water octopods from subtropical Australasia, including: Allopatric populations of Octopus tetricus on the eastern and western coasts of Australia, of which the Western Australian form is speculated to be a distinct or sub-species; and Octopus gibbsi from New Zealand, a proposed synonym of Australian forms. This study employed a combination of molecular and morphological techniques to resolve the taxonomic status of the 'tetricus complex'. Phylogenetic analyses (based on five mitochondrial genes: 12S rRNA, 16S rRNA, COI, COIII and Cytb) and Generalised Mixed Yule Coalescent (GMYC) analysis (based on COI, COIII and Cytb) distinguished eastern and Western Australian O. tetricus as distinct species, while O. gibbsi was found to be synonymous with the east Australian form (BS = >97, PP = 1; GMYC p = 0.01). Discrete morphological differences in mature male octopuses (based on sixteen morphological traits) provided further evidence of cryptic speciation between east (including New Zealand) and west coast populations; although females proved less useful in morphological distinction among members of the tetricus complex. In addition, phylogenetic analyses suggested populations of octopuses currently treated under the name Octopus vulgaris are paraphyletic; providing evidence of cryptic speciation among global populations of O. vulgaris, the most commercially valuable octopus species worldwide.

  18. RETROSPECTIVE REVIEW OF MORTALITY IN GIANT PACIFIC OCTOPUS (ENTEROCTOPUS DOFLEINI).

    PubMed

    Seeley, Kathryn E; Clayton, Leigh A; Hadfield, Catherine A; Muth, Dillon; Mankowski, Joseph L; Kelly, Kathleen M

    2016-03-01

    The giant Pacific octopus (Enteroctopus dofleini) is a popular exhibit species in public display aquaria, but information on health and disease is limited. This retrospective review evaluates time in collection and describes antemortem clinical signs and pathology of giant Pacific octopuses in an aquarium setting. Between March 2004 and December 2013, there were 19 mortalities: eight males, 10 females, and one individual whose sex was not recorded. Average time spent in collection for all octopuses was 375 ± 173 days (males 351 ± 148 days, females 410 ± 196 days). Ten (52.6%) of the octopuses were sexually mature at the time of death, six (31.6%) were not sexually mature, and reproductive status could not be determined in three octopuses (15.8%). Minimal changes were noted on gross necropsy but branchitis was histologically evident in 14 octopuses, often in conjunction with amoeboid or flagellate parasites. Senescence, parasitism, and husbandry were all important contributors to mortality and should be considered when caring for captive octopuses.

  19. Arm coordination in octopus crawling involves unique motor control strategies.

    PubMed

    Levy, Guy; Flash, Tamar; Hochner, Binyamin

    2015-05-04

    To cope with the exceptional computational complexity that is involved in the control of its hyper-redundant arms [1], the octopus has adopted unique motor control strategies in which the central brain activates rather autonomous motor programs in the elaborated peripheral nervous system of the arms [2, 3]. How octopuses coordinate their eight long and flexible arms in locomotion is still unknown. Here, we present the first detailed kinematic analysis of octopus arm coordination in crawling. The results are surprising in several respects: (1) despite its bilaterally symmetrical body, the octopus can crawl in any direction relative to its body orientation; (2) body and crawling orientation are monotonically and independently controlled; and (3) contrasting known animal locomotion, octopus crawling lacks any apparent rhythmical patterns in limb coordination, suggesting a unique non-rhythmical output of the octopus central controller. We show that this uncommon maneuverability is derived from the radial symmetry of the arms around the body and the simple pushing-by-elongation mechanism by which the arms create the crawling thrust. These two together enable a mechanism whereby the central controller chooses in a moment-to-moment fashion which arms to recruit for pushing the body in an instantaneous direction. Our findings suggest that the soft molluscan body has affected in an embodied way [4, 5] the emergence of the adaptive motor behavior of the octopus.

  20. Allopatric Speciation within a Cryptic Species Complex of Australasian Octopuses

    PubMed Central

    Amor, Michael D.; Norman, Mark D.; Cameron, Hayley E.; Strugnell, Jan M.

    2014-01-01

    Despite extensive revisions over recent decades, the taxonomy of benthic octopuses (Family Octopodidae) remains in a considerable flux. Among groups of unresolved status is a species complex of morphologically similar shallow-water octopods from subtropical Australasia, including: Allopatric populations of Octopus tetricus on the eastern and western coasts of Australia, of which the Western Australian form is speculated to be a distinct or sub-species; and Octopus gibbsi from New Zealand, a proposed synonym of Australian forms. This study employed a combination of molecular and morphological techniques to resolve the taxonomic status of the ‘tetricus complex’. Phylogenetic analyses (based on five mitochondrial genes: 12S rRNA, 16S rRNA, COI, COIII and Cytb) and Generalised Mixed Yule Coalescent (GMYC) analysis (based on COI, COIII and Cytb) distinguished eastern and Western Australian O. tetricus as distinct species, while O. gibbsi was found to be synonymous with the east Australian form (BS = >97, PP = 1; GMYC p = 0.01). Discrete morphological differences in mature male octopuses (based on sixteen morphological traits) provided further evidence of cryptic speciation between east (including New Zealand) and west coast populations; although females proved less useful in morphological distinction among members of the tetricus complex. In addition, phylogenetic analyses suggested populations of octopuses currently treated under the name Octopus vulgaris are paraphyletic; providing evidence of cryptic speciation among global populations of O. vulgaris, the most commercially valuable octopus species worldwide. PMID:24964133

  1. [Effect of freezing and cooking on the texture and electrophoretic pattern of the proteins of octopus arms (Octopus vulgaris)].

    PubMed

    Reyes, Genara; Nirchio, Mauro; Bello, Rafael; Borderías, Javier

    2014-09-01

    Texture is the most valuable feature in cephalopods. Factors that mainly affect the texture of octopus are: freezing, scalding and cooking. The aim of this study was to assess the effect of freezing, scalding and length of cooking time on the texture and electrophoretic pattern of proteins of octopus arms. Octopuses were trapped near Margarita Island and carried with ice to the laboratory where they were packed and subjected to: a) freezing at -27 degrees C or at -20 degrees C b) scalding c) cooking for 25 min, 35 min or 45 min. Shear force was determined by Kramer cell on strips of octopus arms. SDS-PAGE was done according to the Laemmli method with 12% polyacrilamide gels. A sensory evaluation of the preference of texture was carried out using a hedonic scale of 7-points and a non-trained panel. Octopus texture was not affected by freezing temperature or scalding. Frozen octopus was softer after cooking than fresh. The longer the cooking time was, the softer the octopus was. Myosin heavy chain (MHC) was not significantly affected by scalding or cooking; however large aggregates heavier than MHC, new bands and loss of resolution of the bands appeared. Myosin and paramyosin bands were more affected by freezing prior to cooking.

  2. Photoreversibility and photostability in films of octopus rhodopsin isolated from octopus photoreceptor membranes.

    PubMed

    Paternolli, Cristina; Neebe, Martin; Stura, Enrico; Barbieri, Francesca; Ghisellini, Paola; Hampp, Norbert; Nicolini, Claudio

    2009-03-15

    In this work, a new biomaterial resulting from the isolation of octopus rhodopsin (OR) starting from octopus photoreceptor membranes is presented. Mass spectroscopic characterization was employed in order to verify the presence of rhodopsin in the extract. Photoreversibility and photochromic properties were investigated using spectrophotometric measurements and pulsed light. Thin films of OR were realized using the gel-matrix entrapment method in polyvinyl alcohol solution. The results indicate that the photoreversibility and the photostability of the OR in gel-matrices are maintained. Several measurements were performed to test the stability of the resulting biomaterial in time and at room temperature. Preliminary tests demonstrate that the photoreversibility and the photostability are still found after few days from the biomaterial preparation and after the exposure for several hours at room temperature.

  3. Invertebrate neurobiology: visual direction of arm movements in an octopus.

    PubMed

    Niven, Jeremy E

    2011-03-22

    An operant task in which octopuses learn to locate food by a visual cue in a three-choice maze shows that they are capable of integrating visual and mechanosensory information to direct their arm movements to a goal.

  4. Materials science: How to suck like an octopus

    NASA Astrophysics Data System (ADS)

    Wilker, Jonathan J.

    2017-06-01

    Rubber sheets that reversibly bind and release substrates have been made by copying a subtlety in the shape of octopus suckers. The findings reveal how macro-scale biological structures can influence function. See Letter p.396

  5. Cadherin genes and evolutionary novelties in the octopus.

    PubMed

    Wang, Z Yan; Ragsdale, Clifton W

    2017-09-01

    All animals with large brains must have molecular mechanisms to regulate neuronal process outgrowth and prevent neurite self-entanglement. In vertebrates, two major gene families implicated in these mechanisms are the clustered protocadherins and the atypical cadherins. However, the molecular mechanisms utilized in complex invertebrate brains, such as those of the cephalopods, remain largely unknown. Recently, we identified protocadherins and atypical cadherins in the octopus. The octopus protocadherin expansion shares features with the mammalian clustered protocadherins, including enrichment in neural tissues, clustered head-to-tail orientations in the genome, and a large first exon encoding all cadherin domains. Other octopus cadherins, including a newly-identified cadherin with 77 extracellular cadherin domains, are elevated in the suckers, a striking cephalopod novelty. Future study of these octopus genes may yield insights into the general functions of protocadherins in neural wiring and cadherin-related proteins in complex morphogenesis. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Amino and fatty acid dynamics of octopus (Octopus vulgaris) early life stages under ocean warming.

    PubMed

    Lopes, Vanessa M; Faleiro, Filipa; Baptista, Miguel; Pimentel, Marta S; Paula, José R; Couto, Ana; Bandarra, Narcisa; Anacleto, Patrícia; Marques, António; Rosa, Rui

    2016-01-01

    The oceans are becoming warmer, and the higher temperatures are expected to have a major impact on marine life at different levels of biological organization, especially at the most vulnerable early life stages. Thus, we hypothesize that the future warmer scenarios (here +3 °C) will affect the biochemical composition (amino acid - AA, and fatty acid-FA) of octopod (Octopus vulgaris) embryos and recently-hatched pelagic paralarvae. The main essential amino acids found in octopus embryos were arginine, leucine and lysine; while aspartic and glutamic acids, and taurine were the main non-essential amino acids. Palmitic, eicosapentaenoic and docosahexaenoic acids were the main FAs found in octopus tissues. Relevant ontogenetic changes were observed, namely a steep decrease in the content of many AAs, and a selective retention of FAs, thus evidencing the protein-based metabolism of these cephalopods. Temperature per si did not elicit significant changes in the overall FA composition, but was responsible for a significant decrease in the content of several AAs, indicating increased embryonic consumption.

  7. [Reproduction, diet and fishery of Octopus (Octopus) hubbsorum (Mollusca: Cephalopoda) in the coast of Oaxaca, Mexico].

    PubMed

    Alejo-Plata, Maria del Carmen; Gómez-Márquez, José Luis; Carrillo, Samuel Ramos; Herrera-Galindo, Jorge Eduardo

    2009-01-01

    The octopus Octopus hubbsorum (Berry 1953) ranges widely and is important for the artisanal fishery in Puerto Angel, Oaxaca, Mexico. Samples were taken approximately at every two weeks from January 2002 to November 2003. All organisms were measured for dorsal mantle length (DLM) and total weight; sex and maturity gonadic stage were registered. For the stomach content analysis, frequency of occurrence and emptying indexes were used. The 352 organisms caught ranged from 4 to 18 cm in DLM; the sex ratio was different from 1 (chi2 = 24.2, p<0.05) throughout the year. The maximum values of the GSI appeared in May (4.1917 for females; 1.2675 in males). LDM for first sexual maturity (LDM50%) was 16 cm (females) and 14 cm (males). Octopus hubbsorum moves from deep waters to the coast, probably in search of better conditions, and lays masses of eggs on rocky substrata. They are fished from March to October, with higher intensity in April and May. Fishing effort was related to the oceanographic characteristics and the atmospheric conditions of the area. From April to September the CPUE monthly mean was 20-10 kg/divers/day. Using the CPUE and environmental condition relationship, the estimated adequate superficial temperature for fishing is 29.5 degrees C.

  8. Multiple object redshift determinations in clusters of galaxies using OCTOPUS

    NASA Astrophysics Data System (ADS)

    Mazure, A.; Proust, D.; Sodre, L.; Lund, G.; Capelato, H.

    1987-03-01

    The ESO multiobject facility, Octopus, was used to observe a sample of galaxy clusters such as SC2008-565 in an attempt to collect a large set of individual radial velocities. A dispersion of 114 A/mm was used, providing spectral coverage from 3800 to 5180 A. Octopus was found to be a well-adapted instrument for the rapid and simultaneous determination of redshifts in cataloged galaxy clusters.

  9. Multiple object redshift determinations in clusters of galaxies using OCTOPUS

    NASA Astrophysics Data System (ADS)

    Mazure, A.; Proust, D.; Sodre, L.; Capelato, H. V.; Lund, G.

    1988-04-01

    The ESO multiobject facility, Octopus, was used to observe a sample of galaxy clusters such as SC2008-565 in an attempt to collect a large set of individual radial velocities. A dispersion of 114 A/mm was used, providing spectral coverage from 3800 to 5180 A. Octopus was found to be a well-adapted instrument for the rapid and simultaneous determination of redshifts in cataloged galaxy clusters.

  10. The morphology and adhesion mechanism of Octopus vulgaris suckers.

    PubMed

    Tramacere, Francesca; Beccai, Lucia; Kuba, Michael; Gozzi, Alessandro; Bifone, Angelo; Mazzolai, Barbara

    2013-01-01

    The octopus sucker represents a fascinating natural system performing adhesion on different terrains and substrates. Octopuses use suckers to anchor the body to the substrate or to grasp, investigate and manipulate objects, just to mention a few of their functions. Our study focuses on the morphology and adhesion mechanism of suckers in Octopus vulgaris. We use three different techniques (MRI, ultrasonography, and histology) and a 3D reconstruction approach to contribute knowledge on both morphology and functionality of the sucker structure in O. vulgaris. The results of our investigation are two-fold. First, we observe some morphological differences with respect to the octopus species previously studied (i.e., Octopus joubini, Octopus maya, Octopus bimaculoides/bimaculatus and Eledone cirrosa). In particular, in O. vulgaris the acetabular chamber, that is a hollow spherical cavity in other octopuses, shows an ellipsoidal cavity which roof has an important protuberance with surface roughness. Second, based on our findings, we propose a hypothesis on the sucker adhesion mechanism in O. vulgaris. We hypothesize that the process of continuous adhesion is achieved by sealing the orifice between acetabulum and infundibulum portions via the acetabular protuberance. We suggest this to take place while the infundibular part achieves a completely flat shape; and, by sustaining adhesion through preservation of sucker configuration. In vivo ultrasonographic recordings support our proposed adhesion model by showing the sucker in action. Such an underlying physical mechanism offers innovative potential cues for developing bioinspired artificial adhesion systems. Furthermore, we think that it could possibly represent a useful approach in order to investigate any potential difference in the ecology and in the performance of adhesion by different species.

  11. The Morphology and Adhesion Mechanism of Octopus vulgaris Suckers

    PubMed Central

    Tramacere, Francesca; Beccai, Lucia; Kuba, Michael; Gozzi, Alessandro; Bifone, Angelo; Mazzolai, Barbara

    2013-01-01

    The octopus sucker represents a fascinating natural system performing adhesion on different terrains and substrates. Octopuses use suckers to anchor the body to the substrate or to grasp, investigate and manipulate objects, just to mention a few of their functions. Our study focuses on the morphology and adhesion mechanism of suckers in Octopus vulgaris. We use three different techniques (MRI, ultrasonography, and histology) and a 3D reconstruction approach to contribute knowledge on both morphology and functionality of the sucker structure in O. vulgaris. The results of our investigation are two-fold. First, we observe some morphological differences with respect to the octopus species previously studied (i.e., Octopus joubini, Octopus maya, Octopus bimaculoides/bimaculatus and Eledone cirrosa). In particular, in O. vulgaris the acetabular chamber, that is a hollow spherical cavity in other octopuses, shows an ellipsoidal cavity which roof has an important protuberance with surface roughness. Second, based on our findings, we propose a hypothesis on the sucker adhesion mechanism in O. vulgaris. We hypothesize that the process of continuous adhesion is achieved by sealing the orifice between acetabulum and infundibulum portions via the acetabular protuberance. We suggest this to take place while the infundibular part achieves a completely flat shape; and, by sustaining adhesion through preservation of sucker configuration. In vivo ultrasonographic recordings support our proposed adhesion model by showing the sucker in action. Such an underlying physical mechanism offers innovative potential cues for developing bioinspired artificial adhesion systems. Furthermore, we think that it could possibly represent a useful approach in order to investigate any potential difference in the ecology and in the performance of adhesion by different species. PMID:23750233

  12. Pull or Push? Octopuses Solve a Puzzle Problem.

    PubMed

    Richter, Jonas N; Hochner, Binyamin; Kuba, Michael J

    2016-01-01

    Octopuses have large brains and exhibit complex behaviors, but relatively little is known about their cognitive abilities. Here we present data from a five-level learning and problem-solving experiment. Seven octopuses (Octopus vulgaris) were first trained to open an L shaped container to retrieve food (level 0). After learning the initial task all animals followed the same experimental protocol, first they had to retrieve this L shaped container, presented at the same orientation, through a tight fitting hole in a clear Perspex partition (level 1). This required the octopuses to perform both pull and release or push actions. After reaching criterion the animals advanced to the next stage of the test, which would be a different consistent orientation of the object (level 2) at the start of the trial, an opaque barrier (level 3) or a random orientation of the object (level 4). All octopuses were successful in reaching criterion in all levels of the task. At the onset of each new level the performance of the animals dropped, shown as an increase in working times. However, they adapted quickly so that overall working times were not significantly different between levels. Our findings indicate that octopuses show behavioral flexibility by quickly adapting to a change in a task. This can be compared to tests in other species where subjects had to conduct actions comprised of a set of motor actions that cannot be understood by a simple learning rule alone.

  13. Analyzing octopus movements using three-dimensional reconstruction.

    PubMed

    Yekutieli, Yoram; Mitelman, Rea; Hochner, Binyamin; Flash, Tamar

    2007-09-01

    Octopus arms, as well as other muscular hydrostats, are characterized by a very large number of degrees of freedom and a rich motion repertoire. Over the years, several attempts have been made to elucidate the interplay between the biomechanics of these organs and their control systems. Recent developments in electrophysiological recordings from both the arms and brains of behaving octopuses mark significant progress in this direction. The next stage is relating these recordings to the octopus arm movements, which requires an accurate and reliable method of movement description and analysis. Here we describe a semiautomatic computerized system for 3D reconstruction of an octopus arm during motion. It consists of two digital video cameras and a PC computer running custom-made software. The system overcomes the difficulty of extracting the motion of smooth, nonrigid objects in poor viewing conditions. Some of the trouble is explained by the problem of light refraction in recording underwater motion. Here we use both experiments and simulations to analyze the refraction problem and show that accurate reconstruction is possible. We have used this system successfully to reconstruct different types of octopus arm movements, such as reaching and bend initiation movements. Our system is noninvasive and does not require attaching any artificial markers to the octopus arm. It may therefore be of more general use in reconstructing other nonrigid, elongated objects in motion.

  14. Pull or Push? Octopuses Solve a Puzzle Problem

    PubMed Central

    Richter, Jonas N.; Hochner, Binyamin; Kuba, Michael J.

    2016-01-01

    Octopuses have large brains and exhibit complex behaviors, but relatively little is known about their cognitive abilities. Here we present data from a five-level learning and problem-solving experiment. Seven octopuses (Octopus vulgaris) were first trained to open an L shaped container to retrieve food (level 0). After learning the initial task all animals followed the same experimental protocol, first they had to retrieve this L shaped container, presented at the same orientation, through a tight fitting hole in a clear Perspex partition (level 1). This required the octopuses to perform both pull and release or push actions. After reaching criterion the animals advanced to the next stage of the test, which would be a different consistent orientation of the object (level 2) at the start of the trial, an opaque barrier (level 3) or a random orientation of the object (level 4). All octopuses were successful in reaching criterion in all levels of the task. At the onset of each new level the performance of the animals dropped, shown as an increase in working times. However, they adapted quickly so that overall working times were not significantly different between levels. Our findings indicate that octopuses show behavioral flexibility by quickly adapting to a change in a task. This can be compared to tests in other species where subjects had to conduct actions comprised of a set of motor actions that cannot be understood by a simple learning rule alone. PMID:27003439

  15. How do octopuses use their arms?

    PubMed

    Mather, J A

    1998-09-01

    A taxonomy of the movement patterns of the 8 flexible arms of octopuses is constructed. Components consist of movements of the arm itself, the ventral suckers and their stalks, as well as the relative position of arms and the skin web between them. Within 1 arm, combinations of components result in a variety of behaviors. At the level of all arms, 1 group of behaviors is described as postures, on the basis of the spread of all arms and the web to make a 2-dimensional surface whose position differs in the 3rd dimension. Another group of arm behaviors is actions, more or less coordinated and involving several to all arms. Arm control appears to be based on radial symmetry, relative equipotentiality of all arms, relative independence of each arm, and separability of components within the arm. The types and coordination of arm behaviors are discussed with relationship to biomechanical limits, muscle structures, and neuronal programming.

  16. Neuropeptidergic control of Octopus oviducal gland.

    PubMed

    Di Cristo, Carlo; Di Cosmo, Anna

    2007-01-01

    The oviducal gland of the female of Octopus vulgaris lies about halfway along the oviduct. Progesterone and 17beta-estradiol receptors have been immunolocalized in the nuclei of the cells of the glandular compartment of previtellogenic glands. We also have evidence of FMRFamide-like and cGnRH-I-like immunoreactivity in the nerve endings that reach the oviducal gland. Moreover, we have recently shown APGWamide immunoreactivity in the glandular cells of the inner part of the oviducal gland. Here we report a review on these findings as well as our latest studies on the effect that neuropeptides may exert on the secretory activity of the oviducal gland. cAMP seems to be a possible second messenger involved in such a process. We discuss the findings of a neuropeptidergic action on the glandular cells of oviducal gland in a more complex frame of molecules, such as steroids, biogenic amines and neuromodulators, controlling the activity of the gland.

  17. Primary Processes in Photolysis of Octopus Rhodopsin

    PubMed Central

    Ohtani, Hiroyuki; Kobayashi, Takayoshi; Tsuda, Motoyuki; Ebrey, Thomas G.

    1988-01-01

    The photolysis of octopus rhodopsin was studied by picosecond time-resolved spectroscopy at physiological temperature (8°C) and by steady-state spectroscopy at very low temperature (10 K). Both hypsorhodopsin and bathorhodopsin were formed from a bathorhodopsin-like red-shifted intermediate “primerhodopsin,” which was the primary photoproduct with our time resolution (36 ps). Though it was proposed that hypsorhodopsin is formed solely by a multiphoton process, the present results obtained by using blue light pulses (461 nm) of low intensity showed that hypsorhodopsin is formed by a single photon mechanism via thermal decay from primerhodopsin. When the excitation intensity is increased, a channel for the photochemical formation of hypsorhodopsin from primerhodopsin is opened. There are two thermal pathways leading from primerhodopsin. One process is the formation of hypsorhodopsin, which is later thermally converted to bathorhodopsin, and the other is the direct formation of bathorhodopsin from primerhodopsin. The formation efficiencies at room temperature of hypsorhodopsin and bathorhodopsin at very low excitation intensity were estimated to be larger than 0.6 and smaller than 0.4, respectively. The formation of hypsorhodopsin was also found in the early stages of the irradiation of octopus rhodopsin with weak continuous light at 10 K. However bathorhodopsin is formed three times more efficiently than hypsorhodopsin at 10 K. At physiological temperatures the formation of hypsorhodopsin in D2O takes place more slowly than in H2O. This indicates that the lifetime of primerhodopsin is decreased by H2O/D2O exchange. The rate constant for the primerhodopsin → bathorhodopsin conversion is more sensitive than that for the primerhodopsin → hypsorhodopsin conversion. The transformation of hypsorhodopsin to bathorhodopsin shows no deuterium effect at low temperature. PMID:19431715

  18. The Atlantic Ocean: An Impassable Barrier for the Common Octopus, Octopus vulgaris

    NASA Astrophysics Data System (ADS)

    Perez-Viscasillas, J.; Schizas, N. V.; Jassoud, A.

    2016-02-01

    Octopus vulgaris (Lamarck 1798) inhabits the Mediterranean, the temperate and tropical coastal waters of the Atlantic Ocean and is also present in the south Indian Ocean and Japan. We questioned the reported widespread distribution and especially the amphi-Atlantic distribution of O. vulgaris by comparing patterns of genetic variation in the Cytochrome Oxidase Subunit I (COI), the 17th intron of the Na(+)/K(+)-ATPase alpha subunit (Na/K-ATPase 17th intron), and 16S genes from several populations throughout the presumed distribution. Bayesian genealogies based on COI sequences resulted in three monophyletic lineages: a Caribbean, a Eurafrican and a Japanese one. The Eurafrican lineage is more closely related to the Japanese than to the Caribbean lineage. Within the Caribbean, the most common mitochondrial haplotype is shared by all sampled locations except for Curaçao. The most common COI haplotype in the Eurafrican group is shared by all populations. The Caribbean octopus exhibits a divergence of 11.5% compared to the Eurafrican and Japanese octopus, whereas the latter groups are 3.1% divergent. The Na/K-ATPase 17th intron data from Caribbean and Mediterranean/Atlantic Spain octopods is concordant with the mitochondrial data set, separating these two populations. The 16s data is still being analysed, but preliminary analysis supports the dual population hypothesis. The reciprocal monophyly observed with both COI and Na/K-ATPase 17th intron between the Caribbean and European O. vulgaris suggests the historical cessation of gene flow between the two sides of the Atlantic and highlights the presence of a highly differentiated Caribbean lineage.

  19. Developmental and physiological challenges of octopus (Octopus vulgaris) early life stages under ocean warming.

    PubMed

    Repolho, Tiago; Baptista, Miguel; Pimentel, Marta S; Dionísio, Gisela; Trübenbach, Katja; Lopes, Vanessa M; Lopes, Ana Rita; Calado, Ricardo; Diniz, Mário; Rosa, Rui

    2014-01-01

    The ability to understand and predict the effects of ocean warming (under realistic scenarios) on marine biota is of paramount importance, especially at the most vulnerable early life stages. Here we investigated the impact of predicted environmental warming (+3 °C) on the development, metabolism, heat shock response and antioxidant defense mechanisms of the early stages of the common octopus, Octopus vulgaris. As expected, warming shortened embryonic developmental time by 13 days, from 38 days at 18 °C to 25 days at 21 °C. Concomitantly, survival decreased significantly (~29.9 %). Size at hatching varied inversely with temperature, and the percentage of smaller premature paralarvae increased drastically, from 0 % at 18 °C to 17.8 % at 21 °C. The metabolic costs of the transition from an encapsulated embryo to a free planktonic form increased significantly with warming, and HSP70 concentrations and glutathione S-transferase activity levels were significantly magnified from late embryonic to paralarval stages. Yet, despite the presence of effective antioxidant defense mechanisms, ocean warming led to an augmentation of malondialdehyde levels (an indicative of enhanced ROS action), a process considered to be one of the most frequent cellular injury mechanisms. Thus, the present study provides clues about how the magnitude and rate of ocean warming will challenge the buffering capacities of octopus embryos and hatchlings' physiology. The prediction and understanding of the biochemical and physiological responses to warmer temperatures (under realistic scenarios) is crucial for the management of highly commercial and ecologically important species, such as O. vulgaris.

  20. Molecular and functional characterization of a novel gonadotropin-releasing-hormone receptor isolated from the common octopus (Octopus vulgaris).

    PubMed

    Kanda, Atsuhiro; Takahashi, Toshio; Satake, Honoo; Minakata, Hiroyuki

    2006-04-01

    GnRH (gonadotropin-releasing hormone) plays a pivotal role in the regulation of reproduction in vertebrates through interaction with a specific receptor. Previously, we isolated a GnRH homologue, oct-GnRH, from the common octopus (Octopus vulgaris). In the present study, we have identified a GnRH receptor (oct-GnRHR) specific for oct-GnRH from Octopus brain. Oct-GnRHR includes domains and motifs typical of vertebrate GnRH receptors. The intron-inserted positions are conserved between oct-GnRHR and the chordate GnRHR genes. The oct-GnRHR expressed in Xenopus (South African clawed frog) oocytes was responsive to oct-GnRH, but not to any other HPLC fractions of the Octopus brain extract. These results show that oct-GnRHR is an authentic receptor for oct-GnRH. Southern blotting of reverse-transcription PCR products revealed that the oct-GnRHR mRNA was widely distributed in the central and peripheral nervous systems and in several peripheral tissues. In situ hybridization showed that oct-GnRHR mRNA was expressed in some regions involved in autonomic functions, feeding, memory and movement. Oct-GnRH was shown to induce steroidogenesis of testosterone, progesterone and 17beta-oestradiol in Octopus ovary and testis, where oct-GnRHR was abundantly expressed. These results suggest that oct-GnRH, like its vertebrate counterparts, acts as a multifunctional neurotransmitter, neuromodulator and hormone-like factor, both in Octopus central nervous system and peripheral tissues, and that both structure and functions of the GnRH family are, at least partially, evolutionarily conserved between octopuses and chordates.

  1. Molecular and functional characterization of a novel gonadotropin-releasing-hormone receptor isolated from the common octopus (Octopus vulgaris)

    PubMed Central

    Kanda, Atsuhiro; Takahashi, Toshio; Satake, Honoo; Minakata, Hiroyuki

    2005-01-01

    GnRH (gonadotropin-releasing hormone) plays a pivotal role in the regulation of reproduction in vertebrates through interaction with a specific receptor. Previously, we isolated a GnRH homo-logue, oct-GnRH, from the common octopus (Octopus vulgaris). In the present study, we have identified a GnRH receptor (oct-GnRHR) specific for oct-GnRH from Octopus brain. Oct-GnRHR includes domains and motifs typical of vertebrate GnRH receptors. The intron-inserted positions are conserved between oct-GnRHR and the chordate GnRHR genes. The oct-GnRHR expressed in Xenopus (South African clawed frog) oocytes was responsive to oct-GnRH, but not to any other HPLC fractions of the Octopus brain extract. These results show that oct-GnRHR is an authentic receptor for oct-GnRH. Southern blotting of reverse-transcription PCR products revealed that the oct-GnRHR mRNA was widely distributed in the central and peripheral nervous systems and in several peripheral tissues. In situ hybridiz-ation showed that oct-GnRHR mRNA was expressed in some regions involved in autonomic functions, feeding, memory and movement. Oct-GnRH was shown to induce steroidogenesis of testosterone, progesterone and 17β-oestradiol in Octopus ovary and testis, where oct-GnRHR was abundantly expressed. These results suggest that oct-GnRH, like its vertebrate counterparts, acts as a multifunctional neurotransmitter, neuromodulator and hormone-like factor, both in Octopus central nervous system and peripheral tissues, and that both structure and functions of the GnRH family are, at least partially, evolutionarily conserved between octopuses and chordates. PMID:16367741

  2. Fecal hormones measured within giant Pacific octopuses Enteroctopus dofleini.

    PubMed

    Larson, Shawn E; Anderson, Roland C

    2010-09-01

    The captive husbandry of giant Pacific octopuses Enteroctopus dofleini is well understood, but their endocrine signatures are not well documented. The major vertebrate reproductive hormones--estrogen, progesterone, and testosterone--and the stress-related hormone corticosterone are relatively well known for many vertebrate species. However, few studies on these hormones within invertebrates have been conducted. Our hypothesis was that endocrine signatures within octopuses are similar to those found within vertebrates in response to reproductive activity and stress. Using standard immunoassay techniques, we measured fecal steroids within fecal samples collected from five female and three male giant Pacific octopuses housed at the Seattle Aquarium. The mean estrogen level ranged from 3.67 to 99.39 ng/g of feces, progesterone ranged from 44.35 to 231.71 ng/g feces, testosterone ranged from 9.30 to 18.18 ng/g feces, and corticosterone ranged from 10.91 to 22.14 ng/g feces. The results suggest that octopus fecal hormones are similar to those in vertebrates and may be useful in measuring ovarian activity and stress within captive female giant Pacific octopuses.

  3. Kinematic decomposition and classification of octopus arm movements

    PubMed Central

    Zelman, Ido; Titon, Myriam; Yekutieli, Yoram; Hanassy, Shlomi; Hochner, Binyamin; Flash, Tamar

    2013-01-01

    The octopus arm is a muscular hydrostat and due to its deformable and highly flexible structure it is capable of a rich repertoire of motor behaviors. Its motor control system uses planning principles and control strategies unique to muscular hydrostats. We previously reconstructed a data set of octopus arm movements from records of natural movements using a sequence of 3D curves describing the virtual backbone of arm configurations. Here we describe a novel representation of octopus arm movements in which a movement is characterized by a pair of surfaces that represent the curvature and torsion values of points along the arm as a function of time. This representation allowed us to explore whether the movements are built up of elementary kinematic units by decomposing each surface into a weighted combination of 2D Gaussian functions. The resulting Gaussian functions can be considered as motion primitives at the kinematic level of octopus arm movements. These can be used to examine underlying principles of movement generation. Here we used combination of such kinematic primitives to decompose different octopus arm movements and characterize several movement prototypes according to their composition. The representation and methodology can be applied to the movement of any organ which can be modeled by means of a continuous 3D curve. PMID:23745113

  4. Patterns of arm muscle activation involved in octopus reaching movements.

    PubMed

    Gutfreund, Y; Flash, T; Fiorito, G; Hochner, B

    1998-08-01

    The extreme flexibility of the octopus arm allows it to perform many different movements, yet octopuses reach toward a target in a stereotyped manner using a basic invariant motor structure: a bend traveling from the base of the arm toward the tip (Gutfreund et al., 1996a). To study the neuronal control of these movements, arm muscle activation [electromyogram (EMG)] was measured together with the kinematics of reaching movements. The traveling bend is associated with a propagating wave of muscle activation, with maximal muscle activation slightly preceding the traveling bend. Tonic activation was occasionally maintained afterward. Correlation of the EMG signals with the kinematic variables (velocities and accelerations) reveals that a significant part of the kinematic variability can be explained by the level of muscle activation. Furthermore, the EMG level measured during the initial stages of movement predicts the peak velocity attained toward the end of the reaching movement. These results suggest that feed-forward motor commands play an important role in the control of movement velocity and that simple adjustment of the excitation levels at the initial stages of the movement can set the velocity profile of the whole movement. A simple model of octopus arm extension is proposed in which the driving force is set initially and is then decreased in proportion to arm diameter at the bend. The model qualitatively reproduces the typical velocity profiles of octopus reaching movements, suggesting a simple control mechanism for bend propagation in the octopus arm.

  5. Laboratory maintenance, breeding, rearing, and biomedical research potential of the Yucatan octopus (Octopus maya).

    PubMed

    Van Heukelem, W F

    1977-10-01

    Eggs of the Yucatan octopus, Octopus maya, were collected at Campeche, Mexico, transported to Hawaii, and incubated in glass funnels. Benthic juveniles hatched from the large (17-mm) eggs and were reared on a variety of live and frozen foods. As many as 200 animals were reared for the first month in a 20-liter aquarium. No disease or parasite problems were encountered and nearly all well-fed juveniles survived to sexual maturity. The species was reared through four generations in the laboratory. Animals weighed 0.1 g at hatching and within 8.5 months attained an average weight of 3231 g. Mating was promiscuous and sperm were stored in the oviducts until spawning. Spawning occurred at 8-9 months of age. Up to 5,000 eggs were laid by large females and nearly 100% of fertilized eggs developed to hatching. Females brooded eggs during the 45-day period of development but artificial was as successful as natural incubation by the mother. Pos-reproductive senescent decline of both males and females was rapid and average life span was 300 days from hatching. Areas of biomedical research in which O maya could be a useful model were suggested and included neurobiology, comparative psychology, ontogeny of behavior, immunology, endocrinology, and studies of aging.

  6. Dietary Effect on the Proteome of the Common Octopus (Octopus vulgaris) Paralarvae

    PubMed Central

    Varó, Inmaculada; Cardenete, Gabriel; Hontoria, Francisco; Monroig, Óscar; Iglesias, José; Otero, Juan J.; Almansa, Eduardo; Navarro, Juan C.

    2017-01-01

    Nowadays, the common octopus (Octopus vulgaris) culture is hampered by massive mortalities occurring during early life-cycle stages (paralarvae). Despite the causes of the high paralarvae mortality are not yet well-defined and understood, the nutritional stress caused by inadequate diets is pointed out as one of the main factors. In this study, the effects of diet on paralarvae is analyzed through a proteomic approach, to search for novel biomarkers of nutritional stress. A total of 43 proteins showing differential expression in the different conditions studied have been identified. The analysis highlights proteins related with the carbohydrate metabolism: glyceraldehyde-3-phosphate-dedydrogenase (GAPDH), triosephosphate isomerase; other ways of energetic metabolism: NADP+-specific isocitrate dehydrogenase, arginine kinase; detoxification: glutathione-S-transferase (GST); stress: heat shock proteins (HSP70); structural constituent of eye lens: S-crystallin 3; and cytoskeleton: actin, actin-beta/gamma1, beta actin. These results allow defining characteristic proteomes of paralarvae depending on the diet; as well as the use of several of these proteins as novel biomarkers to evaluate their welfare linked to nutritional stress. Notably, the changes of proteins like S-crystallin 3, arginine kinase and NAD+ specific isocitrate dehydrogenase, may be related to fed vs. starving paralarvae, particularly in the first 4 days of development. PMID:28567020

  7. Dynamic mimicry in an Indo-Malayan octopus.

    PubMed

    Norman, M D; Finn, J; Tregenza, T

    2001-09-07

    During research dives in Indonesia (Sulawesi and Bali), we filmed a distinctive long-armed octopus, which is new to science. Diving over 24 h periods revealed that the 'mimic octopus' emerges during daylight hours to forage on sand substrates in full view of pelagic fish predators. We observed nine individuals of this species displaying a repertoire of postures and body patterns, several of which are clearly impersonations of venomous animals co-occurring in this habitat. This 'dynamic mimicry' avoids the genetic constraints that may limit the diversity of genetically polymorphic mimics but has the same effect of decreasing the frequency with which predators encounter particular mimics. Additionally, our observations suggest that the octopus makes decisions about the most appropriate form of mimicry to use, allowing it to enhance further the benefits of mimicking toxic models by employing mimicry according to the nature of perceived threats.

  8. LINCS: Livermore's network architecture. [Octopus computing network

    SciTech Connect

    Fletcher, J.G.

    1982-01-01

    Octopus, a local computing network that has been evolving at the Lawrence Livermore National Laboratory for over fifteen years, is currently undergoing a major revision. The primary purpose of the revision is to consolidate and redefine the variety of conventions and formats, which have grown up over the years, into a single standard family of protocols, the Livermore Interactive Network Communication Standard (LINCS). This standard treats the entire network as a single distributed operating system such that access to a computing resource is obtained in a single way, whether that resource is local (on the same computer as the accessing process) or remote (on another computer). LINCS encompasses not only communication but also such issues as the relationship of customer to server processes and the structure, naming, and protection of resources. The discussion includes: an overview of the Livermore user community and computing hardware, the functions and structure of each of the seven layers of LINCS protocol, the reasons why we have designed our own protocols and why we are dissatisfied by the directions that current protocol standards are taking.

  9. Role of olfaction in Octopus vulgaris reproduction.

    PubMed

    Polese, Gianluca; Bertapelle, Carla; Di Cosmo, Anna

    2015-01-01

    The olfactory system in any animal is the primary sensory system that responds to chemical stimuli emanating from a distant source. In aquatic animals "Odours" are molecules in solution that guide them to locate food, partners, nesting sites, and dangers to avoid. Fish, crustaceans and aquatic molluscs possess sensory systems that have anatomical similarities to the olfactory systems of land-based animals. Molluscs are a large group of aquatic and terrestrial animals that rely heavily on chemical communication with a generally dispersed sense of touch and chemical sensitivity. Cephalopods, the smallest class among extant marine molluscs, are predators with high visual capability and well developed vestibular, auditory, and tactile systems. Nevertheless they possess a well developed olfactory organ, but to date almost nothing is known about the mechanisms, functions and modulation of this chemosensory structure in octopods. Cephalopod brains are the largest of all invertebrate brains and across molluscs show the highest degree of centralization. The reproductive behaviour of Octopus vulgaris is under the control of a complex set of signal molecules such as neuropeptides, neurotransmitters and sex steroids that guide the behaviour from the level of individuals in evaluating mates, to stimulating or deterring copulation, to sperm-egg chemical signalling that promotes fertilization. These signals are intercepted by the olfactory organs and integrated in the olfactory lobes in the central nervous system. In this context we propose a model in which the olfactory organ and the olfactory lobe of O. vulgaris could represent the on-off switch between food intake and reproduction.

  10. Purification, cloning, and immunological characterization of arginine kinase, a novel allergen of Octopus fangsiao.

    PubMed

    Shen, Hai-Wang; Cao, Min-Jie; Cai, Qiu-Feng; Ruan, Mi-Mi; Mao, Hai-Yan; Su, Wen-Jin; Liu, Guang-Ming

    2012-03-07

    Arginine kinase (AK) is an important enzyme participating in energy metabolism in invertebrates, but, to date, there have been no reports that AK from octopus is an allergen. In this study, octopus AK was purified, and its molecular biological, immunological, and physicochemical characterizations were analyzed. The results showed that octopus AK was purified and confirmed by mass spectrometry for the first time, and its molecular mass was 38 kDa. The full-length gene sequence of octopus AK encompassed 1209 bp and was predicted to encode a protein with 348 amino acid residues. The homology of octopus AK and crustacean AK was about 54%, but the similarity between their three-dimensional structures was high. Octopus AK could react with mouse anti-shrimp AK and rabbit anti-crab AK polyclonal antibody singly. Octopus AK could also react with specific IgE of the sera from octopus-allergic patients effectively, whereas crab AK could inhibit the reaction between them. Finally, the IgE-binding activity of octopus AK could be reduced in the processes of thermal or acid-alkali treatment. In summary, AK was identified as a novel allergen in octopus, which had a sensitizing ability similar to that of crustacean AK. This is significant in allergy diagnosis and the treatment of octopus-allergic disorders.

  11. I Know My Neighbour: Individual Recognition in Octopus vulgaris

    PubMed Central

    Tricarico, Elena; Borrelli, Luciana; Gherardi, Francesca; Fiorito, Graziano

    2011-01-01

    Background Little is known about individual recognition (IR) in octopuses, although they have been abundantly studied for their sophisticated behaviour and learning capacities. Indeed, the ability of octopuses to recognise conspecifics is suggested by a number of clues emerging from both laboratory studies (where they appear to form and maintain dominance hierarchies) and field observations (octopuses of neighbouring dens display little agonism between each other). To fill this gap in knowledge, we investigated the behaviour of 24 size-matched pairs of Octopus vulgaris in laboratory conditions. Methodology/Principal Findings The experimental design was composed of 3 phases: Phase 1 (acclimatization): 12 “sight-allowed” (and 12 “isolated”) pairs were maintained for 3 days in contiguous tanks separated by a transparent (and opaque) partition to allow (and block) the vision of the conspecific; Phase 2 (cohabitation): members of each pair (both sight-allowed and isolated) were transferred into an experimental tank and were allowed to interact for 15 min every day for 3 consecutive days; Phase 3 (test): each pair (both sight-allowed and isolated) was subject to a switch of an octopus to form pairs composed of either familiar (“sham switches”) or unfamiliar conspecifics (“real switches”). Longer latencies (i.e. the time elapsed from the first interaction) and fewer physical contacts in the familiar pairs as opposed to the unfamiliar pairs were used as proxies for recognition. Conclusions Octopuses appear able to recognise conspecifics and to remember the individual previously met for at least one day. To the best of our knowledge, this is the first experimental study showing the occurrence of a form of IR in cephalopods. Future studies should clarify whether this is a “true” IR. PMID:21533257

  12. Behavior and Body Patterns of the Larger Pacific Striped Octopus.

    PubMed

    Caldwell, Roy L; Ross, Richard; Rodaniche, Arcadio; Huffard, Christine L

    2015-01-01

    Over thirty years ago anecdotal accounts of the undescribed Larger Pacific Striped Octopus suggested behaviors previously unknown for octopuses. Beak-to-beak mating, dens shared by mating pairs, inking during mating and extended spawning were mentioned in publications, and enticed generations of cephalopod biologists. In 2012-2014 we were able to obtain several live specimens of this species, which remains without a formal description. All of the unique behaviors listed above were observed for animals in aquaria and are discussed here. We describe the behavior, body color patterns, and postures of 24 adults maintained in captivity. Chromatophore patterns of hatchlings are also shown.

  13. Behavior and Body Patterns of the Larger Pacific Striped Octopus

    PubMed Central

    Caldwell, Roy L.; Ross, Richard; Rodaniche, Arcadio; Huffard, Christine L.

    2015-01-01

    Over thirty years ago anecdotal accounts of the undescribed Larger Pacific Striped Octopus suggested behaviors previously unknown for octopuses. Beak-to-beak mating, dens shared by mating pairs, inking during mating and extended spawning were mentioned in publications, and enticed generations of cephalopod biologists. In 2012–2014 we were able to obtain several live specimens of this species, which remains without a formal description. All of the unique behaviors listed above were observed for animals in aquaria and are discussed here. We describe the behavior, body color patterns, and postures of 24 adults maintained in captivity. Chromatophore patterns of hatchlings are also shown. PMID:26266543

  14. Distribution of GABA-like immunoreactivity in the octopus brain.

    PubMed

    Cornwell, C J; Messenger, J B; Williamson, R

    1993-09-10

    This paper presents the first evidence that some neurons in the octopus CNS contain delta-amino butyric acid (GABA). Using conventional immunohistochemical methods with appropriate controls, we obtained positive staining with an antibody to GABA in fibres in the neuropil of many lobes of the brain of the northern octopus Eledone cirrhosa. In several lobes cell bodies were also stained. Staining was not uniformly distributed in the brain nor within a particular lobe: some regions stained strongly, others not at all. These findings suggest that GABA should be added to the already long list of putative neurotransmitters in the cephalopod CNS.

  15. Photoreverse Reaction Dynamics of Octopus Rhodopsin

    PubMed Central

    Inoue, Keiichi; Tsuda, Motoyuki; Terazima, Masahide

    2007-01-01

    Photoreverse reactions of octopus rhodopsin (Rh) from acid-metarhodopsin (Acid-Meta), which is the final product of the photoreaction of Rh, to Rh were studied by the time-resolved transient absorption and transient grating methods. The time course of the absorption signal showed a rapid change within 500 ns followed by one phase with a time constant of ∼470 μs, whereas the transient grating signal indicates three phases with time constants of <500 ns, ∼490 μs, and 2.6 ms. The faster two phases indicate the conformational change in the vicinity of the chromophore, and the slowest one represents conformational change far from the chromophore. The absorption spectrum of the first intermediate created just after the laser excitation (<500 ns) is already very similar to the final product, Rh. This behavior is quite different from that of the forward reaction from Rh to Acid-Meta, in which several intermediates with different absorption spectra are involved within 50 ns–500 μs. This result indicates that the conformation around the chromophore is easily adjusted from all-trans to 11-cis forms compared with that from 11-cis to all-trans forms. Furthermore, it was found that the protein energy is quickly relaxed after the excitation. One of the significantly different properties between Rh and Acid-Meta is the diffusion coefficient (D). D is reduced by about half the transformation from Rh to Acid-Meta. This large reduction was interpreted in terms of the helix opening of the Rh structure. PMID:17325000

  16. Oxygen equilibria of Octopus dofleini hemocyanin.

    PubMed

    Miller, K I

    1985-08-13

    Oxygen binding by Octopus dofleini hemocyanin was examined under very nearly physiological conditions. The effects of pH, ionic composition, temperature, and aggregation were controlled so that the role each plays in modulating oxygen binding can be isolated. There is a very large effect of pH on affinity, the Bohr effect (delta log P50/delta pH = -1.7), which is the same at 10 and 20 degrees C. However, cooperativity is substantially altered over the same range of pHs at the two temperatures. The allosteric properties were examined by comparing the experimental data points to curves generated by use of the Monod-Wyman-Changeux model. A computer-fitting process was developed which allowed the individual allosteric parameters to be varied independently until the best fit could be determined. The relationship between kR and kT is responsible for the effect of pH on cooperativity. A change in the allosteric properties of the T form is primarily responsible for the differences due to temperature. Changing cation concentrations when the molecule is in the fully aggregated 51S form alters affinity without influencing cooperativity. The effect of Mg2+ is much greater than that of Na+. If the 51S decamer is dissociated to 11S monomers by removing divalent cations, oxygen binding is noncooperative. There is evidence for negative cooperativity, indicating heterogeneity of function within the subunit which contains seven oxygen binding domains. Association into decamers generates conformational change which results in a much wider range of allosteric function.

  17. Morphologic, cytometric and functional characterization of the common octopus (Octopus vulgaris) hemocytes.

    PubMed

    Castellanos-Martínez, S; Prado-Alvarez, M; Lobo-da-Cunha, A; Azevedo, C; Gestal, C

    2014-05-01

    The hemocytes of Octopus vulgaris were morphologically and functionally characterized. Light and electron microscopy (TEM and SEM), and flow cytometry analyses revealed the existence of two hemocyte populations. Large granulocytes showed U-shaped nucleus, a mean of 11.6 μm±1.2 in diameter with basophilic granules, polysaccharide and lysosomic deposits in the cytoplasm. Small granulocytes measured a mean of 8.1 μm±0.7 in diameter, and have a round nucleus occupying almost the entire cell and few or not granules in the cytoplasm. Flow cytometry analysis showed that large granulocytes are the principal cells that develop phagocytosis of latex beads (rising up to 56%) and ROS after zymosan stimulation. Zymosan induced the highest production of both ROS and NO. This study is the first tread towards understanding the O. vulgaris immune system by applying new tools to provide a most comprehensive morpho-functional study of their hemocytes.

  18. Malabsorption syndrome observed in the common octopus Octopus vulgaris infected with Aggregata octopiana (Protista: Apicomplexa).

    PubMed

    Gestal, C; Páez de la Cadena, M; Pascual, S

    2002-08-15

    Octopus vulgaris infected with Aggregata octopiana were collected from an open-water culture system in the Ría of Aldán (NW Spain). Digestive tract infection values were determined with the use of a Neubauer chamber by counting the number of A. octopiana sporocysts. After determining enzyme activity values by the colorimetric Api-Zym system Biomerieux, one representative enzyme of glycosidases, peptid hydrolases and phosphoric hydrolases showing high activity was spectrophotometrically analysed. The enzymes were maltase and leucine-aminopeptidase (LAP) involved in the absorption process, and acid phosphatase, a lysosomic enzyme, respectively. Enzymatic activity of maltase and LAP decreased significantly, with increased sporocyst counts. However, acid phosphatase activity increased with severity of infection, indicating the presence of degradative enzymes from phagocytic cells in the infected area. A detrimental effect on gastrointestinal function may result from a decrease or malfunction of absorption enzymes. The results suggest a malabsorption syndrome resulting from parasitic infection.

  19. Nitric oxide is necessary for visual learning in Octopus vulgaris.

    PubMed

    Robertson, J D; Bonaventura, J; Kohm, A; Hiscat, M

    1996-12-22

    We recently reported that inhibition of nitric oxide synthase (NOS) in Octopus vulgaris by intramuscular injections of an analog of L-arginine, N-omega-nitro-L-arginine methyl ester (L-NAME), blocked touch learning in Octopus vulgaris. The inactive enantiomorph (D-NAME), which had no effect on learning, was used for control. We now report that essentially the same procedures block visual learning in this animal. We used a visual paradigm in which the octopus was trained to respond positively to a smooth black plastic ball 2.5 cm diameter and negatively to a similar white ball, or vice versa. One set of eight animals was trained to the black ball positive, and another set of six to the white ball positive. Each set was trained at different times by two different trainers. We found that a 1 h pretreatment with the nitric oxide synthase inhibitor L-NAME blocks visual learning in Octopus vulgaris in both sets of animals.

  20. The inkless octopuses (Cephalopoda: Octopodidae) of the southwest Atlantic.

    PubMed

    Gleadall, Ian G; Guerrero-Kommritz, Juergen; Hochberg, Frederick G; Laptikhovsky, Vladimir V

    2010-06-01

    Three inkless octopodids are described from the continental shelf off southeastern South America. These octopuses are a non-commercial by-catch in the Falkland Islands fishery. Muusoctopus eureka (Robson, 1929) is one of two common inkless octopuses and is of medium size, with orange-pink skin and a distinctive pattern of irregular dark markings, interspersed with white spots visible only in living or freshly dead specimens. The second common inkless octopus is M. longibrachus akambei, a new subspecies of the Chilean species Muusoctopus longibrachus ( Ibáñez, Sepúlveda and Chong, 2006 ). It has slender arms and is much larger at full maturity than M. eureka. It is a plain orange color when alive, pinkish cream when preserved. Muusoctopus bizikovi, sp. nov., is a smaller, rarer species, colored wine-red whether alive or preserved, and has a vestigial ink duct between the digestive gland and the anus. Relations with other species are discussed. This group of octopuses has often been associated with the genus Benthoctopus Grimpe, 1921 , which is a junior synonym of Bathypolypus Grimpe (a genus of small species characterized by much shorter arms and males with a robust copulatory organ bearing transverse lamellae). It is argued that the misleading characterization of the so-called Benthoctopus group of species as "smooth skinned" is based upon the artefactual appearance of specimens fixed and preserved suboptimally following a detrimental freeze-thaw cycle of fisheries material previously frozen while at sea.

  1. Detection of early glaucomatous progression with octopus cluster trend analysis.

    PubMed

    Naghizadeh, Farzaneh; Holló, Gábor

    2014-01-01

    To compare the ability of Corrected Cluster Trend Analysis (CCTA) and Cluster Trend Analysis (CTA) with event analysis of Octopus visual field series to detect early glaucomatous progression. One eye of 15 healthy, 19 ocular hypertensive, 20 preperimetric, and 51 perimetric glaucoma (PG) patients were investigated with Octopus normal G2 test at 6-month intervals for 1.5 to 3 years. Progression was defined with significant worsening in any of the 10 Octopus clusters with CCTA, and event analysis criteria, respectively. With event analysis, 9 PG eyes showed localized progression and 1 diffuse mean defect (MD) worsening. With CCTA, progression was indicated in 1 normal, 1 ocular hypertensive, and 1 preperimetric glaucoma eyes due to vitreous floaters, and 28 PG eyes including all 9 eyes with localized progression with event analysis. The locations of CCTA progression matched those found with event analysis in all 9 cases. In 17 of the remaining 19 eyes, progressing clusters matched the locations that were suspicious but not definitive for progression with event analysis. In the eye with diffuse MD worsening, CTA found significant progression for 7 clusters. For global MD progression rate, eyes worsened with CCTA only did not differ from the stable eyes but had significantly smaller progression rates than the eyes progressed with event analysis (P=0.0002). In PG, Octopus CCTA and CTA are clinically useful to identify early progression and areas suspicious for early progression. However, in some eyes with no glaucomatous visual field damage, vitreous floaters may cause progression artifacts.

  2. Dancing With an Octopus: The Graceful Art of Collaboration

    ERIC Educational Resources Information Center

    Russell, Elizabeth Morgan

    2008-01-01

    Collaboration--working with like-minded others to achieve a common purpose--is an action-oriented strategy that can be considered as a way of reaching your goals. Because collaboration, as in dancing with an octopus, requires keeping track of many different points (or tentacles), planners who know when collaborations are more likely to work and…

  3. Nervous control of reproduction in Octopus vulgaris: a new model.

    PubMed

    Di Cristo, Carlo

    2013-06-01

    The classic study of Wells and Wells on the control of reproduction in Octopus demonstrated that the activity of the subpedunculate lobe of the brain and environmental illumination both inhibit the release of an unknown gonadotropin from the optic gland. This inhibitory control may be exerted by the neuropeptide Phe-Met-Arg-Phe-NH₂ (FMRFamide). It was later demonstrated that the olfactory lobe is also likely to be involved in the control of optic gland activity. The presence of gonadotropin-releasing hormone in the olfactory lobe suggested that it might exert an excitatory action on optic gland activity. Other neuropeptides have now been localised in the olfactory lobe: neuropeptide Y, galanin, corticotropin-releasing factor, Ala-Pro-Gly-Trp-NH₂ (APGWamide), as well as steroidogenic enzymes and an oestrogen receptor orthologue. This supports the hypothesis that this lobe may also play a part in the control of reproduction in Octopus. The olfactory lobe receives distant chemical stimuli and also appears to be an integrative centre containing a variety of neuropeptides involved in controlling the onset of sexual maturation of Octopus, via the optic gland hormone. This review attempts to summarise current knowledge about the role of the olfactory lobe and optic gland in the control of sexual maturation in Octopus, in the light of new findings and in the context of molluscan comparative physiology.

  4. Dancing With an Octopus: The Graceful Art of Collaboration

    ERIC Educational Resources Information Center

    Russell, Elizabeth Morgan

    2008-01-01

    Collaboration--working with like-minded others to achieve a common purpose--is an action-oriented strategy that can be considered as a way of reaching your goals. Because collaboration, as in dancing with an octopus, requires keeping track of many different points (or tentacles), planners who know when collaborations are more likely to work and…

  5. Two distinct light regulated G-proteins in octopus photoreceptors.

    PubMed

    Tsuda, M; Tsuda, T

    1990-04-09

    Two distinct light-regulated G-proteins were found in octopus photoreceptors. Gip, a 41 kDa protein from washed microvilli, was ADP ribosylated by pertussis toxin in the presence of GDP in the dark. Light and GTP analogues were inhibitory as with transducin (Gt; G-protein in vertebrate photoreceptors). G34, a 34 kDa protein from fresh octopus retina, was ADP ribosylated by both cholera and pertussis toxin in the dark. Light inhibited labeling of the 34 kDa protein by both toxins. Unlike Gip, G34 is soluble and is very labile to heat, freezing and thawing. Prolonged incubation of octopus retina with cholera toxin and labeled NAD produced an additional radioactive band at 46 kDa. Labeling of the 46 kDa protein, Gsp, was greatly enhanced by GTP analogues, but inhibited by a GDP analogue as with Gs in hormone-sensitive adenylate cyclase. In contrast to Gip and G34, labeling of the 46 kDa protein (Gsp) was not influenced by light. The two distinct light-regulated G-proteins, Gip and G34, found in octopus photoreceptors might be involved in either phototransduction or photoadaptation. The function of Gsp is not known.

  6. Video playback demonstrates episodic personality in the gloomy octopus.

    PubMed

    Pronk, R; Wilson, D R; Harcourt, R

    2010-04-01

    Coleoid cephalopods, including octopuses, cuttlefish and squid, rely mainly on visual signals when interacting with conspecifics, predators and prey. Presenting visual stimuli, such as models, photographs, mirrors and live conspecifics, can thus provide insight into cephalopod behaviour. These methods, however, have limitations - mirrors and live animals lack experimental control, whereas models and photographs sacrifice motion-based information. Video playback addresses these issues by presenting controlled, moving and realistic stimuli but, to date, video playback has not been used successfully with any cephalopod. Here, we developed a video playback technique for the gloomy octopus (Octopus tetricus) that incorporated recent advances in video technology. We then used this technique to test for personality, which we defined as behavioural differences between individuals that are consistent over time and across ecologically important contexts. We captured wild octopuses and tested them on 3 separate days over a 10 day period. On each test day, subjects were presented with videos of a food item, a novel object and a conspecific. These represented a foraging, novel and threatening context, respectively. A fourth video without a moving stimulus controlled for the playback monitor itself and potential artifacts associated with video playback. Experimental stimuli evoked unambiguous and biologically appropriate responses from the subjects. Furthermore, individuals' responses to the three experimental contexts were highly correlated within a given test day. However, within a given context, individuals behaved inconsistently across the 3 test days. The reordering of ranks suggests that rather than fulfilling the criteria for personality, gloomy octopus show temporal discontinuities, and hence display episodic personality.

  7. Resonance Raman spectroscopy of octopus rhodopsin and its photoproducts

    SciTech Connect

    Pande, C.; Pande, A.; Yue, K.T.; Callender, R.; Ebrey, T.G.; Tsuda, M.

    1987-08-11

    The authors report here the resonance Raman spectra of octopus rhodopsin and its photoproducts, bathorhodopsin and acid metarhodopsin. These studies were undertaken in order to make comparisons with the well-studied bovine pigments, so as to understand the similarities and the differences in pigment structure and photochemical processes between vertebrates and invertebrates. The flow method was used to obtain the Raman spectrum of rhodopsin at 13 /sup 0/C. The bathorhodopsin spectrum was obtained by computer subtraction of the spectra containing different photostationary mixtures of rhodopsin, isorhodopsin, hypsorhodopsin, and bathorhodopsin, obtained at 12 K using the pump-probe technique and from measurements at 80 K. Like their bovine counterparts, the Schiff base vibrational mode appears at approx. 1660 cm/sup -1/ in octopus rhodopsin and the photoproducts, bathorhodopsin and acid metarhodopsin, suggesting a proteonated Schiff base linkage between the chromophore and the protein. Differences between the Raman spectra of octopus rhodopsin and bathorhodopsin indicate that the formation of bathorhodopsin is associated with chromophore isomerization. This inference is substantiated by the chromophore chemical extraction data which show that, like the bovine system, octopus rhodopsin is an 11-cis pigment, while the photoproducts contain an all-trans pigment, in agreement with the previous work. The octopus rhodopsin and bathorhodopsin spectra show marked differences from their bovine counterparts in other respects, however. The differences are most dramatic in the structure-sensitive fingerprint and the HOOP regions. Thus, it appears that although the two species differ in the specific nature of the chromophore-protein interactions, the general process of visual transduction is the same.

  8. Brain and behavioural evidence for rest-activity cycles in Octopus vulgaris.

    PubMed

    Brown, Euan R; Piscopo, Stefania; De Stefano, Rosanna; Giuditta, Antonio

    2006-09-25

    Octopus vulgaris maintained under a 12/12h light/dark cycle exhibit a pronounced nocturnal activity pattern. Animals deprived of rest during the light period show a marked 'rebound' in activity in the following 24h. 'Active' octopuses attack faster than 'quiet' animals and brain activity recorded electrically intensifies during 'quiet' behaviour. Thus, in Octopus as in vertebrates, brain areas involved in memory or 'higher' processes exhibit 'off-line' activity during rest periods.

  9. Removal of copper from Octopus vulgaris haemocyanin. Preparation of the half-apo and apo derivatives.

    PubMed Central

    Beltramini, M; Ricchelli, F; Piazzesi, A; Barel, A; Salvato, B

    1984-01-01

    The two copper ions bound in the active site of Octopus vulgaris haemocyanin can be removed by cyanide. The two metal ions react with the ligand sequentially. In this paper the preparation of Octopus half-apo-haemocyanin, containing at the active site a single copper ion, is described. Moreover, the conditions to obtain Octopus apo-haemocyanin, containing less than 3% of copper still bound, are given. PMID:6477505

  10. Removal of copper from Octopus vulgaris haemocyanin. Preparation of the half-apo and apo derivatives.

    PubMed

    Beltramini, M; Ricchelli, F; Piazzesi, A; Barel, A; Salvato, B

    1984-08-01

    The two copper ions bound in the active site of Octopus vulgaris haemocyanin can be removed by cyanide. The two metal ions react with the ligand sequentially. In this paper the preparation of Octopus half-apo-haemocyanin, containing at the active site a single copper ion, is described. Moreover, the conditions to obtain Octopus apo-haemocyanin, containing less than 3% of copper still bound, are given.

  11. Toxin and species identification of toxic octopus implicated into food poisoning in Taiwan.

    PubMed

    Wu, Ya-Jung; Lin, Chun-Lan; Chen, Chien-Hung; Hsieh, Cheng-Hong; Jen, Hsiao-Chin; Jian, Shi-Jie; Hwang, Deng-Fwu

    2014-12-01

    A food poisoning incident due to ingestion of unknown octopus occurred in Taipei in December, 2010. The serum and urine from victims (male 38 and 43 years old) were collected, determined the toxicity, and identified tetrodotoxin (TTX) by high-performance liquid chromatography with tandem mass spectrometry (LC-MS/MS). It was found that only urine contained the trace of TTX. Then, two retained specimen (one without blue ring in the skin and another with small blue ring in the skin) were collected from victims and examined for the toxicity and toxin. Meanwhile, 6 specimens of octopus without blue ring in the skin and 4 specimens of octopus with blue ring in the skin were re-collected from the market. Both retained octopus samples were found to contain TTX. However, re-collected market's octopus without blue ring in the skin did not show to contain TTX the and was identified as Octopus aegina by using the analysis of cytochrome b gene (Cyt b) and cytochrome c oxidase subunit I gene (COI). Only octopus with blue ring in the skin contained TTX and was identified as Hapalochlaena fasciata by using the analysis of Cyt b and COI. Therefore, this octopus food poisoning was caused by toxic octopus H. fasciata and the causative agent was TTX.

  12. Interaction of rhodopsin, G-protein and kinase in octopus photoreceptors.

    PubMed

    Tsuda, M; Hirata, H; Tsuda, T

    1992-12-01

    Light induced phosphorylation of octopus rhodopsin was greatly enhanced by guanosine 5'-O-(3-thiotriphosphate) (GTP gamma S), suggesting that the kinases are involved in regulating interaction between rhodopsin and G-protein. We determined phosphorylated peptides of octopus rhodopsin in the presence or absence of GTP gamma S. Possible phosphorylation sites for octopus rhodopsin enhanced by GTP gamma S were Thr329, Thr330 and/or Thr336, which suggest that the G-protein associates with cytoplasmic loops including C-terminal peptide in the seventh helix of octopus rhodopsin.

  13. Identification of a single phosphorylation site within octopus rhodopsin.

    PubMed

    Ohguro, H; Yoshida, N; Shindou, H; Crabb, J W; Palczewski, K; Tsuda, M

    1998-12-01

    Light-dependent phosphorylation of rhodopsin (Rho) is a first step in the desensitization of the signaling state of the receptor during vertebrate and invertebrate visual transduction. We found that only 358Ser of the photoactivated octopus Rho (oRho*) was phosphorylated by octopus rhodopsin kinase (oRK). Tryptic truncation of the C-terminal PPQGY repeats of oRho that follow the phosphorylation region did not influence spectral or G-protein activation properties of oRho but abolished phosphorylation. Despite significant structural differences between oRK and mammalian RK, these results provide further evidence of the importance of singly phosphorylated species of Rho* in the generation of arrestin binding sites.

  14. Nitric oxide is required for tactile learning in Octopus vulgaris.

    PubMed

    Robertson, J D; Bonaventura, J; Kohm, A P

    1994-06-22

    Nitric oxide, produced by nitric oxide synthase in brain tissue, is essential for several different kinds of learning in vertebrates. We present the first evidence that it is also essential for learning in an invertebrate. Intramuscular injections of an inhibitor of the enzyme completely block touch learning in Octopus vulgaris. Eight control animals learned a touch paradigm, but none of eight synthase-inhibited ones learned it.

  15. Retrograde intraaxonal transport of horseradish peroxidase by neurons in octopus.

    PubMed

    Monsell, E M; Cottee, L J

    1980-01-13

    While retrograde axonal transport is the basis of a widely used neuroanatomical method, it has been rigorously demonstrated in vivo only in a few vertebrate species and not yet in an invertebrate. Evidence is presented that motor neurons of the octopus stellate ganglion are capable of retrograde intraaxonal transport of horeseradish peroxidase. This demonstration shows that retrograde transport occurs in widely divergent groups of animals, and may be a general property of neurons.

  16. Expression and distribution of octopus gonadotropin-releasing hormone in the central nervous system and peripheral organs of the octopus (Octopus vulgaris) by in situ hybridization and immunohistochemistry.

    PubMed

    Iwakoshi-Ukena, Eiko; Ukena, Kazuyoshi; Takuwa-Kuroda, Kyoko; Kanda, Atshuhiro; Tsutsui, Kazuyoshi; Minakata, Hiroyuki

    2004-09-20

    We recently purified a peptide with structural features similar to vertebrate gonadotropin-releasing hormone (GnRH) from the brain of Octopus vulgaris, cloned a cDNA encoding the precursor protein, and named it oct-GnRH. In the current study, we investigated the expression and distribution of oct-GnRH throughout the central nervous system (CNS) and peripheral organs of Octopus by in situ hybridization on the basis of the cDNA sequence and by immunohistochemistry using a specific antiserum against oct-GnRH. Oct-GnRH mRNA-expressing cell bodies were located in 10 of 19 lobes in the supraesophageal and subesophageal parts of the CNS. Several oct-GnRH-like immunoreactive fibers were seen in all the neuropils of the CNS lobes. The sites of oct-GnRH mRNA expression and the mature peptide distribution were consistent with each other as judged by in situ hybridization and immunohistochemistry. In addition, many immunoreactive fibers were distributed in peripheral organs such as the heart, the oviduct, and the oviducal gland. Modulatory effects of oct-GnRH on the contractions of the heart and the oviduct were demonstrated. The results suggested that, in the context of reproduction, oct-GnRH is a key peptide in the subpedunculate lobe and/or posterior olfactory lobe-optic gland-gonadal axis, an octopus analogue of the hypothalamo-hypophysial-gonadal axis. It may also act as a modulatory factor in controlling higher brain functions such as feeding, memory, movement, maturation, and autonomic functions

  17. Octopus-like suction cups: from natural to artificial solutions.

    PubMed

    Tramacere, F; Follador, M; Pugno, N M; Mazzolai, B

    2015-05-13

    Octopus suckers are able to attach to all nonporous surfaces and generate a very strong attachment force. The well-known attachment features of this animal result from the softness of the sucker tissues and the surface morphology of the portion of the sucker that is in contact with objects or substrates. Unlike artificial suction cups, octopus suckers are characterized by a series of radial grooves that increase the area subjected to pressure reduction during attachment. In this study, we constructed artificial suction cups with different surface geometries and tested their attachment performances using a pull-off setup. First, smooth suction cups were obtained for casting; then, sucker surfaces were engraved with a laser cutter. As expected, for all the tested cases, the engraving treatment enhanced the attachment performance of the elastomeric suction cups compared with that of the smooth versions. Moreover, the results indicated that the surface geometry with the best attachment performance was the geometry most similar to octopus sucker morphology. The results obtained in this work can be utilized to design artificial suction cups with higher wet attachment performance.

  18. Octopus arm choice is strongly influenced by eye use.

    PubMed

    Byrne, Ruth A; Kuba, Michael J; Meisel, Daniela V; Griebel, Ulrike; Mather, Jennifer A

    2006-09-25

    This study aims to investigate the octopus' eye and arm coordination and raises the question if visual guidance determines choice of arm use. Octopuses possess eight seemingly identical arms but have recently been reported to show a preference as to which arm they use to initiate contact with objects. These animals also exhibit lateralized eye use, therefore, a connection between eye and arm preference seems possible. Seven Octopus vulgaris were observed during approach, contact initiation and exploration of plastic objects that were positioned on three different levels in the water column. The subjects most commonly used an arm to initiate contact with an object that was in a direct line between the eye used to look at the object, and the object itself. This indicates that choice of arm use is spatially rather opportunistic when depending on visual guidance. Additionally, first contact with an object was usually established by the central third of the arm and in arm contact sequences neighboring arms were the most likely to follow an arm already touching the object. Although results point towards strong eye/arm coordination, we did not find lateralized behavior in this experiment. Results are discussed from a neuro-anatomical, behavioral and ecological perspective.

  19. Structure and mechanical properties of Octopus vulgaris suckers.

    PubMed

    Tramacere, Francesca; Kovalev, Alexander; Kleinteich, Thomas; Gorb, Stanislav N; Mazzolai, Barbara

    2014-02-06

    In this study, we investigate the morphology and mechanical features of Octopus vulgaris suckers, which may serve as a model for the creation of a new generation of attachment devices. Octopus suckers attach to a wide range of substrates in wet conditions, including rough surfaces. This amazing feature is made possible by the sucker's tissues, which are pliable to the substrate profile. Previous studies have described a peculiar internal structure that plays a fundamental role in the attachment and detachment processes of the sucker. In this work, we present a mechanical characterization of the tissues involved in the attachment process, which was performed using microindentation tests. We evaluated the elasticity modulus and viscoelastic parameters of the natural tissues (E ∼ 10 kPa) and measured the mechanical properties of some artificial materials that have previously been used in soft robotics. Such a comparison of biological prototypes and artificial material that mimics octopus-sucker tissue is crucial for the design of innovative artificial suction cups for use in wet environments. We conclude that the properties of the common elastomers that are generally used in soft robotics are quite dissimilar to the properties of biological suckers.

  20. Structure and mechanical properties of Octopus vulgaris suckers

    PubMed Central

    Tramacere, Francesca; Kovalev, Alexander; Kleinteich, Thomas; Gorb, Stanislav N.; Mazzolai, Barbara

    2014-01-01

    In this study, we investigate the morphology and mechanical features of Octopus vulgaris suckers, which may serve as a model for the creation of a new generation of attachment devices. Octopus suckers attach to a wide range of substrates in wet conditions, including rough surfaces. This amazing feature is made possible by the sucker's tissues, which are pliable to the substrate profile. Previous studies have described a peculiar internal structure that plays a fundamental role in the attachment and detachment processes of the sucker. In this work, we present a mechanical characterization of the tissues involved in the attachment process, which was performed using microindentation tests. We evaluated the elasticity modulus and viscoelastic parameters of the natural tissues (E ∼ 10 kPa) and measured the mechanical properties of some artificial materials that have previously been used in soft robotics. Such a comparison of biological prototypes and artificial material that mimics octopus-sucker tissue is crucial for the design of innovative artificial suction cups for use in wet environments. We conclude that the properties of the common elastomers that are generally used in soft robotics are quite dissimilar to the properties of biological suckers. PMID:24284894

  1. Nonsomatotopic organization of the higher motor centers in octopus.

    PubMed

    Zullo, Letizia; Sumbre, German; Agnisola, Claudio; Flash, Tamar; Hochner, Binyamin

    2009-10-13

    Hyperredundant limbs with a virtually unlimited number of degrees of freedom (DOFs) pose a challenge for both biological and computational systems of motor control. In the flexible arms of the octopus, simplification strategies have evolved to reduce the number of controlled DOFs. Motor control in the octopus nervous system is hierarchically organized. A relatively small central brain integrates a huge amount of visual and tactile information from the large optic lobes and the peripheral nervous system of the arms and issues commands to lower motor centers controlling the elaborated neuromuscular system of the arms. This unique organization raises new questions on the organization of the octopus brain and whether and how it represents the rich movement repertoire. We developed a method of brain microstimulation in freely behaving animals and stimulated the higher motor centers-the basal lobes-thus inducing discrete and complex sets of movements. As stimulation strength increased, complex movements were recruited from basic components shared by different types of movement. We found no stimulation site where movements of a single arm or body part could be elicited. Discrete and complex components have no central topographical organization but are distributed over wide regions.

  2. Enkephalin-related peptides: direct action on the octopus heart.

    PubMed

    Voigt, K H; Kiehling, C; Frösch, D; Schiebe, M; Martin, R

    1981-11-18

    Immunocytochemical evidence for the occurrence of "vertebrate" peptides in the neuropil of the vena cava [12, 13] and the structural similarity between enkephalin precursor peptides and the molluscan cardioexcitatory peptide [16], lead us to study the action of enkephalin-related peptides on the octopus heart. Systemic hearts of Octopus vulgaris were perfused with sea wate and test substances and a crude extract of vena cave were added for 1 min; frequency and pressure were monitored continuously. The heptapeptide Leu5-enkephalin-Arg6-Phe7 and the Met5-analogue, both in the amidized form, displayed dose-response relationship with a sensitivity of about 10 nmol. The C-terminal tetrapeptide amides, Phe-Leu/Met-Arg-Phe-NH2, were active at the same doses. Opiate receptors do not seem to be involved in this action on the octopus heart, as naloxone treatment had no effect. Whereas the N-terminal portion of the heptapeptide is known to be crucial for activity as an opioid, the C-terminal NH2 group is essential for cardioexcitatory activity.

  3. Octopus vulgaris protein hydrolysates: characterization, antioxidant and functional properties.

    PubMed

    Ben Slama-Ben Salem, Rabeb; Bkhairia, Intidhar; Abdelhedi, Ola; Nasri, Moncef

    2017-05-01

    Composition, functional properties and in vitro antioxidant activities of octopus (Octopus vulgaris) protein hydrolysates (OPHs) were evaluated. OPHs were prepared by treatment with commercial Esperase (OPH-Esp), alkaline protease extract from Zebra blenny (Salaria basilica) (OPH-ZB) and enzyme preparation from Bacillus subtilis A26 (OPH-A26). OPHs showed different degrees of hydrolysis (DH from 17.6 to 21%), and hydrophobic/hydrophilic peptide ratio. The amino acid profiles of OPHs showed a high level of essential amino acids, and Lys was the most abundant amino acid. Enzymatic hydrolysis improved solubility significantly as well as emulsifying and foaming properties of octopus proteins. The emulsifying activity index of OPHs decreased with increasing concentrations. Conversely, the foaming abilities increased as the hydrolysate concentrations increased. For the antioxidant activities, five different in vitro assay systems were investigated. All hydrolysates displayed various degrees and dose dependant antioxidant activities. The highest DPPH scavenging activity and reducing power were achieved by OPH-A26. OPH-Esp displayed the highest ability to prevent the bleaching of β-carotene, whereas OPH-ZB exhibited the highest protection against hydroxyl radical induced DNA breakage. The results suggested that OPHs could be used, as a promising source of functional peptides with antioxidant activities, to formulate functional foods.

  4. 76 FR 55276 - Fisheries of the Exclusive Economic Zone Off Alaska; Octopus in the Bering Sea and Aleutian Islands

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-07

    ... Economic Zone Off Alaska; Octopus in the Bering Sea and Aleutian Islands AGENCY: National Marine Fisheries...; closure. SUMMARY: NMFS is prohibiting retention of octopus in the Bering Sea and Aleutian Islands (BSAI). This action is necessary because the 2011 total allowable catch of octopus in the BSAI has been...

  5. When do octopuses play? Effects of repeated testing, object type, age, and food deprivation on object play in Octopus vulgaris.

    PubMed

    Kuba, Michael J; Byrne, Ruth A; Meisel, Daniela V; Mather, Jennifer A

    2006-08-01

    Studying play behavior in octopuses is an important step toward understanding the phylogenetic origins and function of play as well as the cognitive abilities of invertebrates. Fourteen Octopus vulgaris (7 subadults and 7 adults) were presented 2 Lego objects and 2 different food items on 7 consecutive days under 2 different levels of food deprivation. Nine subjects showed play-like behavior with the Lego objects. There was no significant difference in play-like behavior corresponding to food deprivation, age, and sex of the octopuses. The sequence of behaviors, from exploration to play-like behavior, had a significant influence on the establishment of play-like behavior, as it occurred mostly on Days 3-6 of the 7-day experiment. The pattern of development of play-like activities after a period of exploration and habituation in this study agrees with the hypothesis that object play follows object exploration. A homologous origin of this behavioral trait in vertebrates and invertebrates is highly unlikely, as the last common ancestor might not have had the cognitive capacity to possess this trait.

  6. Identification of Triosephosphate Isomerase as a Novel Allergen in Octopus fangsiao

    USDA-ARS?s Scientific Manuscript database

    A 28 kDa-protein was purified from octopus (Octopus fangsiao) and identified to be triosephosphate isomerase (TIM). The purified TIM is a glycoprotein with 1.7% carbohydrates and the isoelectric point is 7.6. TIM aggregated after heating above 45 °C, and the secondary structure was altered in extre...

  7. Regeneration of bovine and octopus opsins in situ with natural and artificial retinals

    SciTech Connect

    Koutalos, Y.; Ebrey, T.G.; Tsuda, M.; Odashima, K.; Lien, T.; Park, M.H.; Shimizu, N.; Derguini, F.; Nakanishi, K.; Gilson, H.R.; Honig, B. )

    1989-03-21

    The authors consider the problem of color regulation in visual pigments for both bovine rhodopsin and octopus rhodopsin. Both pigments have 11-cis-retinal as their chromophore. These rhodopsins were bleached in their native membranes, and the opsins were regenerated with natural and artificial chromophores. Both bovine and octopus opsins were regenerated with the 9-cis- and 11-cis-retinal isomers, but the octopus opsin was additionally regenerated with the 13-cis and all-trans isomers. Titration of the octopus opsin with 11-cis-retinal gave an extinction coefficient for octopus rhodopsin of 27,000 {plus minus} 3,000 M{sup {minus}1} cm{sup {minus}1} at 475 nm. The absorption maxima of bovine artificial pigments formed by regenerating opsin with the 11-cis dihydro series of chromophores support a color regulation model for bovine rhodopsin in which the chromophore-binding site of the protein has two negative charges: one directly hydrogen bonded to the Schiff base nitrogen and another near carbon-13. Formation of octopus artificial pigments with both all-trans and 11-cis dihydro chromophores leads to a similar model for octopus rhodopsin and metarhodopsin: there are two negative charges in the chromophore-binding site, one directly hydrogen bonded to the Schiff base nitrogen and a second near carbon-13. The interaction of this second charge with the chromophore in octopus rhodopsin is weaker than in bovine, while in metarhodopsin it is as strong as in bovine.

  8. Regeneration of bovine and octopus opsins in situ with natural and artificial retinals.

    PubMed

    Koutalos, Y; Ebrey, T G; Tsuda, M; Odashima, K; Lien, T; Park, M H; Shimizu, N; Derguini, F; Nakanishi, K; Gilson, H R

    1989-03-21

    We consider the problem of color regulation in visual pigments for both bovine rhodopsin (lambda max = 500 nm) and octopus rhodopsin (lambda max = 475 nm). Both pigments have 11-cis-retinal (lambda max = 379 nm, in ethanol) as their chromophore. These rhodopsins were bleached in their native membranes, and the opsins were regenerated with natural and artificial chromophores. Both bovine and octopus opsins were regenerated with the 9-cis- and 11-cis-retinal isomers, but the octopus opsin was additionally regenerated with the 13-cis and all-trans isomers. Titration of the octopus opsin with 11-cis-retinal gave an extinction coefficient for octopus rhodopsin of 27,000 +/- 3000 M-1 cm-1 at 475 nm. The absorption maxima of bovine artificial pigments formed by regenerating opsin with the 11-cis dihydro series of chromophores support a color regulation model for bovine rhodopsin in which the chromophore-binding site of the protein has two negative charges: one directly hydrogen bonded to the Schiff base nitrogen and another near carbon-13. Formation of octopus artificial pigments with both all-trans and 11-cis dihydro chromophores leads to a similar model for octopus rhodopsin and metarhodopsin: there are two negative charges in the chromophore-binding site, one directly hydrogen bonded to the Schiff base nitrogen and a second near carbon-13. The interaction of this second charge with the chromophore in octopus rhodopsin is weaker than in bovine, while in metarhodopsin it is as strong as in bovine.

  9. Bioinspired locomotion and grasping in water: the soft eight-arm OCTOPUS robot.

    PubMed

    Cianchetti, M; Calisti, M; Margheri, L; Kuba, M; Laschi, C

    2015-05-13

    The octopus is an interesting model for the development of soft robotics, due to its high deformability, dexterity and rich behavioural repertoire. To investigate the principles of octopus dexterity, we designed an eight-arm soft robot and evaluated its performance with focused experiments. The OCTOPUS robot presented here is a completely soft robot, which integrates eight arms extending in radial direction and a central body which contains the main processing units. The front arms are mainly used for elongation and grasping, while the others are mainly used for locomotion. The robotic octopus works in water and its buoyancy is close to neutral. The experimental results show that the octopus-inspired robot can walk in water using the same strategy as the animal model, with good performance over different surfaces, including walking through physical constraints. It can grasp objects of different sizes and shapes, thanks to its soft arm materials and conical shape.

  10. Detection and temporal variation of (60)Co in the digestive glands of the common octopus, Octopus vulgaris, in the East China Sea.

    PubMed

    Morita, Takami; Otosaka, Shigeyoshi; Fujimoto, Ken; Nishiuchi, Kou; Kimoto, Katsunori; Yamada, Haruya; Kasai, Hiromi; Minakawa, Masayuki; Yoshida, Katsuhiko

    2010-08-01

    (60)Co were detected in common octopus specimens collected in the East China Sea in 1996-2005. The source of (60)Co has remained unclear yet. Stable isotope analyses showed that there was no difference in stable Co concentrations between octopus samples with (60)Co and without (60)Co. This result showed that the stable Co in the digestive gland of octopus potentially did not include a trace amount of (60)Co and the source of (60)Co existed independently. Furthermore, investigations of octopus in other area and other species indicated that the origin of the source of (60)Co occurred locally in the restricted area in the East China Sea and not in the coastal area of Japan. Concentrations of (60)Co have annually decreased with shorter half-life than the physical half-life. This decrease tendency suggests that the sources of (60)Co were identical and were temporary dumped into the East China Sea as a solid waste.

  11. Electrophysiological properties of octopus neurons of the cat cochlear nucleus: an in vitro study.

    PubMed

    Bal, Ramazan; Baydas, Giyasettin

    2009-06-01

    Electrophysiological studies from mice in vitro have suggested that octopus cells of the mammalian ventral cochlear nucleus (VCN) are anatomically and biophysically specialized for detecting the coincident firing of a population of auditory nerve fibers. Recordings from cats in vivo have shown that octopus cells fire rapidly and with exceptional temporal precision as they convey the timing of that coincidence to higher auditory centers. The current study addresses the question whether the biophysical properties of octopus cells that have until now been examined only in mice, are shared by octopus cells in cats. Whole-cell patch-clamp recordings confirm that octopus cells in brain slices from kittens share the anatomical and biophysical features of octopus cells in mice. As in mice, octopus cells in kittens have large cell bodies and thick dendrites that extend in one direction. Voltage changes produced by depolarizing and hyperpolarizing current injection were small and rapid. Input resistances and membrane time constants in octopus cells of 16-day-old kittens were 15.8 +/- 1.5 MOmega (n = 16) and 1.28 +/- 0.3 ms (n = 16), respectively. Octopus cells fired only a single action potential at the onset of a depolarizing current pulse; suprathreshold stimuli were greater than 1.8 nA. A tetrodotoxin (TTX)-sensitive sodium conductance (gNa) was responsible for the generation of the action potentials. Octopus cells displayed outward rectification that lasted for the duration of the depolarizing pulses. Hyperpolarizations produced by the injection of current exhibited a depolarizing sag of the membrane potential toward the resting value. A 4-aminopyridine (4-AP) and alpha-dendrotoxin (alpha-DTX)-sensitive, low-voltage-activated potassium conductance (gKL) and a ZD7288-sensitive, mixed-cation conductance (gh) were partially activated at rest, giving the octopus cells low input resistances and, as a consequence, brief time constants. In 7-day-old kittens, action potentials

  12. Purification and characterization of phenoloxidase from Octopus ocellatus.

    PubMed

    Fan, Tingjun; Li, Mingyu; Wang, Jing; Yang, Lingling; Cong, Rishan

    2009-10-01

    Phenoloxidase (PO) from ink sacs of Octopus ocellatus was purified by gel-filtration and ion-exchange chromatography, and characterized in terms of its biochemical and enzymatic properties by using L-dihydroxyphenylalanine (L-DOPA) as the specific substrate. It was found that prophenoloxidase from O. ocellatus was isolated as a heterodimeric protein of 153.8 kDa, and two subunits of 75.6 and 73.0 kDa were often detected in preparations after SDS activation. The PO-like activity showed optimal pH of 7.0, optimal temperature of 40 degrees C, and an apparent Km value of 3.1 mM on L-DOPA, and 6.3 mM on catechol, respectively. The PO-like activity was extremely sensitive to 1-phenyl-2-thiourea and sodium sulfite, and very sensitive to ascorbic acid, thiourea, citric acid, and benzoic acid. Together with its specific enzyme activity on catechol and L-DOPA, it can be concluded that the Octopus PO is most probably a typical o-diphenoloxidase. The PO-like activity was also strongly inhibited by Cu(2+), Zn(2+), ethylenediaminetetraacetic acid and diethyldithiocarbamate (DETC), and the DETC-inhibited PO-like activity could be perfectly restored by Cu(2+). These results indicated that Octopus PO is most probably a copper-containing metalloenzyme. All these results implied that the PO from O. ocellatus has the properties of a catechol-type copper-containing o-diphenoloxidase which functions not only as a catalytic enzyme in melanin production in ink sacs but also as a humoral factor in host defense via melaninization as in other crustaceans.

  13. Use of octopus as a bioindicator species: Baseline studies

    SciTech Connect

    Holdway, D.A.; Butty, J.S.; Brennan, S.E.; Ahokas, J.T.

    1995-12-31

    The Australian octopus Octopus pallidus, is abundant, territorial, has a large digestive gland. This study was undertaken to assess octopii as a potential bioindicator species by establishing the efficacy of capturing octopi using traplines, and determining the impact of various modifying factors on the activities of digestive gland mixed-function oxidase (MFO) enzymes including ethoxyresorufin O-deethylase (EROD), ethoxycoumarin O-deethylase (ECOD) and total P-450. Trap success rates in Port Phillip Bay were 15--28% for the ``potentially contaminated`` site and 85% for the reference site. Cytochrome P-450 showed significant seasonal differences, with no site or sex differences. Mean ({+-} SE) Autumn P-450 values of 74.8 ({+-}5.5) pmol/mg protein were higher than Winter values of 51.2 ({+-}7.6), which were higher than Spring values of 21.8 ({+-}4.0) pmol/mg protein. Summer P-450 values of 61.4 ({+-} 9.8) pmol/mg protein were only different from Spring values. Mean ({+-} SE) Spring ECOD activity of 3.3 ({+-} 0.7) pmol/min/mg protein was lower than Summer, Autumn and Winter ECOD values of 8.9 ({+-} 1.6) 6.5 ({+-} 1.2) and 8.6 ({+-} 2.3) pmol/min/mg protein respectively. Females had roughly half the ECOD activities of males (3.8 {+-} 0.8 compared to 7.4 {+-} 0.9 pmol/min/mg protein). All octopi digestive gland EROD activities were low (roughly 0.2 pmol/min/mg protein) with no sex, site nor seasonal differences. Potential for using octopus as a bioindicator appears promising but sensitivity to chemical exposure has yet to be determined.

  14. Directional sensitivity of hair cell afferents in the Octopus statocyst.

    PubMed

    Budelmann, B U; Williamson, R

    1994-02-01

    Changes in threshold sensitivity of hair cell afferents of the macula and crista of the Octopus statocyst were analyzed when the hair cells were stimulated with sinusoidal water movements from different directions. The experiments indicate that cephalopod statocyst hair cells are directionally sensitive in a way that is similar to the responses of the hair cells of the vertebrate vestibular and lateral line systems, with the amplitude of the response changing according to the cosine of the angle by which the direction of the stimulus (the deflection of the ciliary bundle) deviates from the direction of the hair cell's morphological polarization.

  15. The oxidation of Octopus vulgaris hemocyanin by nitrogen oxides.

    PubMed

    Salvato, B; Giacometti, G M; Beltramini, M; Zilio, F; Giacometti, G; Magliozzo, R S; Peisach, J

    1989-01-24

    The reaction of Octopus vulgaris hemocyanin with nitrite was studied under a variety of conditions in which the green half-met derivative is formed. Analytical evidence shows that the amount of chemically detectable nitrite in various samples of the derivative is not proportional to the cupric copper detected by EPR. The kinetics of oxidation of hemocyanin as a function of protein concentration and pH, in the presence of nitrite and ascorbate, is consistent with a scheme in which NO2 is the reactive oxidant. We suggest that the green half-methemocyanin contains a metal center with one cuprous and one cupric copper without an exogenous nitrogen oxide ligand.

  16. Lipid-protein interaction in the photolysis of octopus rhodopsin.

    PubMed

    Tsuda, M; Akino, T

    1981-04-22

    Microvillar membranes of octopus photoreceptor cells were treated with phospholipase A2, phospholipase C, hexane, or their combinations. By these means, various membrane preparations containing qualitatively and quantitatively different lipids were obtained. The lipid composition and phospholipid content of the membrane preparations obtained by the above methods were determined. Photochemical processes in the digitonin extract of the native and treated membranes have been studied by flash photometry. The results suggest that several different variations in the lipids can affect the rates of the photochemical transformations; these are: the content of phospholipid, the amount of unsaturated hydrocarbon chains and free fatty acids.

  17. Comparative analysis of gene expression for convergent evolution of camera eye between octopus and human.

    PubMed

    Ogura, Atsushi; Ikeo, Kazuho; Gojobori, Takashi

    2004-08-01

    Although the camera eye of the octopus is very similar to that of humans, phylogenetic and embryological analyses have suggested that their camera eyes have been acquired independently. It has been known as a typical example of convergent evolution. To study the molecular basis of convergent evolution of camera eyes, we conducted a comparative analysis of gene expression in octopus and human camera eyes. We sequenced 16,432 ESTs of the octopus eye, leading to 1052 nonredundant genes that have matches in the protein database. Comparing these 1052 genes with 13,303 already-known ESTs of the human eye, 729 (69.3%) genes were commonly expressed between the human and octopus eyes. On the contrary, when we compared octopus eye ESTs with human connective tissue ESTs, the expression similarity was quite low. To trace the evolutionary changes that are potentially responsible for camera eye formation, we also compared octopus-eye ESTs with the completed genome sequences of other organisms. We found that 1019 out of the 1052 genes had already existed at the common ancestor of bilateria, and 875 genes were conserved between humans and octopuses. It suggests that a larger number of conserved genes and their similar gene expression may be responsible for the convergent evolution of the camera eye.

  18. Digestive Physiology of Octopus maya and O. mimus: Temporality of Digestion and Assimilation Processes

    PubMed Central

    Gallardo, Pedro; Olivares, Alberto; Martínez-Yáñez, Rosario; Caamal-Monsreal, Claudia; Domingues, Pedro M.; Mascaró, Maite; Sánchez, Ariadna; Pascual, Cristina; Rosas, Carlos

    2017-01-01

    Digestive physiology is one of the bottlenecks of octopus aquaculture. Although, there are successful experimentally formulated feeds, knowledge of the digestive physiology of cephalopods is fragmented, and focused mainly on Octopus vulgaris. Considering that the digestive physiology could vary in tropical and sub-tropical species through temperature modulations of the digestive dynamics and nutritional requirements of different organisms, the present review was focused on the digestive physiology timing of Octopus maya and Octopus mimus, two promising aquaculture species living in tropical (22–30°C) and sub-tropical (15–24°C) ecosystems, respectively. We provide a detailed description of how soluble and complex nutrients are digested, absorbed, and assimilated in these species, describing the digestive process and providing insight into how the environment can modulate the digestion and final use of nutrients for these and presumably other octopus species. To date, research on these octopus species has demonstrated that soluble protein and other nutrients flow through the digestive tract to the digestive gland in a similar manner in both species. However, differences in the use of nutrients were noted: in O. mimus, lipids were mobilized faster than protein, while in O. maya, the inverse process was observed, suggesting that lipid mobilization in species that live in relatively colder environments occurs differently to those in tropical ecosystems. Those differences are related to the particular adaptations of animals to their habitat, and indicate that this knowledge is important when formulating feed for octopus species. PMID:28620313

  19. Digestive Physiology of Octopus maya and O. mimus: Temporality of Digestion and Assimilation Processes.

    PubMed

    Gallardo, Pedro; Olivares, Alberto; Martínez-Yáñez, Rosario; Caamal-Monsreal, Claudia; Domingues, Pedro M; Mascaró, Maite; Sánchez, Ariadna; Pascual, Cristina; Rosas, Carlos

    2017-01-01

    Digestive physiology is one of the bottlenecks of octopus aquaculture. Although, there are successful experimentally formulated feeds, knowledge of the digestive physiology of cephalopods is fragmented, and focused mainly on Octopus vulgaris. Considering that the digestive physiology could vary in tropical and sub-tropical species through temperature modulations of the digestive dynamics and nutritional requirements of different organisms, the present review was focused on the digestive physiology timing of Octopus maya and Octopus mimus, two promising aquaculture species living in tropical (22-30°C) and sub-tropical (15-24°C) ecosystems, respectively. We provide a detailed description of how soluble and complex nutrients are digested, absorbed, and assimilated in these species, describing the digestive process and providing insight into how the environment can modulate the digestion and final use of nutrients for these and presumably other octopus species. To date, research on these octopus species has demonstrated that soluble protein and other nutrients flow through the digestive tract to the digestive gland in a similar manner in both species. However, differences in the use of nutrients were noted: in O. mimus, lipids were mobilized faster than protein, while in O. maya, the inverse process was observed, suggesting that lipid mobilization in species that live in relatively colder environments occurs differently to those in tropical ecosystems. Those differences are related to the particular adaptations of animals to their habitat, and indicate that this knowledge is important when formulating feed for octopus species.

  20. Comparative Analysis of Gene Expression for Convergent Evolution of Camera Eye Between Octopus and Human

    PubMed Central

    Ogura, Atsushi; Ikeo, Kazuho; Gojobori, Takashi

    2004-01-01

    Although the camera eye of the octopus is very similar to that of humans, phylogenetic and embryological analyses have suggested that their camera eyes have been acquired independently. It has been known as a typical example of convergent evolution. To study the molecular basis of convergent evolution of camera eyes, we conducted a comparative analysis of gene expression in octopus and human camera eyes. We sequenced 16,432 ESTs of the octopus eye, leading to 1052 nonredundant genes that have matches in the protein database. Comparing these 1052 genes with 13,303 already-known ESTs of the human eye, 729 (69.3%) genes were commonly expressed between the human and octopus eyes. On the contrary, when we compared octopus eye ESTs with human connective tissue ESTs, the expression similarity was quite low. To trace the evolutionary changes that are potentially responsible for camera eye formation, we also compared octopus-eye ESTs with the completed genome sequences of other organisms. We found that 1019 out of the 1052 genes had already existed at the common ancestor of bilateria, and 875 genes were conserved between humans and octopuses. It suggests that a larger number of conserved genes and their similar gene expression may be responsible for the convergent evolution of the camera eye. PMID:15289475

  1. Seasonal patterns of polycyclic aromatic hydrocarbons in digestive gland and arm of octopus (Octopus vulgaris) from the Northwest Atlantic.

    PubMed

    Semedo, Miguel; Oliveira, Marta; Gomes, Filipa; Reis-Henriques, Maria Armanda; Delerue-Matos, Cristina; Morais, Simone; Ferreira, Marta

    2014-05-15

    Among organic pollutants existing in coastal areas, polycyclic aromatic hydrocarbons (PAHs) are of great concern due to their ubiquity and carcinogenic potential. The aim of this study was to evaluate the seasonal patterns of PAHs in the digestive gland and arm of the common octopus (Octopus vulgaris) from the Northwest Atlantic Portuguese coast. In the different seasons, 18 PAHs were determined and the detoxification capacity of the species was evaluated. Ethoxyresorufin O-deethylase (EROD) and ethoxycoumarin O-deethylase (ECOD) activities were measured to assess phase I biotransformation capacity. Individual PAH ratios were used for major source (pyrolytic/petrogenic) analysis. Risks for human consumption were determined by the total toxicity equivalence approach. Generally, low levels of PAHs were detected in the digestive gland and in the arm of octopus, with a predominance of low molecular over high molecular weight compounds. PAHs exhibited seasonality in the concentrations detected and in their main emission sources. In the digestive gland, the highest total PAH levels were observed in autumn possibly related to fat availability in the ecosystem and food intake. The lack of PAH elimination observed in the digestive gland after captivity could be possibly associated to a low biotransformation capacity, consistent with the negligible/undetected levels of EROD and ECOD activity in the different seasons. The emission sources of PAHs found in the digestive gland varied from a petrogenic profile observed in winter to a pyrolytic pattern in spring. In the arm, the highest PAH contents were observed in June; nevertheless, levels were always below the regulatory limits established for food consumption. The carcinogenic potential calculated for all the sampling periods in the arm were markedly lower than the ones found in various aquatic species from different marine environments. The results presented in this study give relevant baseline data for environmental

  2. Ultra-fast Escape of a Octopus-inspired Rocket

    NASA Astrophysics Data System (ADS)

    Weymouth, Gabriel; Triantafyllou, Michael

    2013-11-01

    The octopus, squid, and other cephalopods inflate with water and then release a jet to accelerate in the opposite direction. This escape mechanism is particularly interesting in the octopus because they become initially quite bluff, yet this does not hinder them in achieving impressive bursts of speed. We examine this somewhat paradoxical maneuver using a simple deflating spheroid model in both potential and viscous flow. We demonstrate that the dynamic reduction of the width of the body completely changes the flow and forces acting on the escaping rocket in three ways. First, a body which reduces in size can generate an added mass thrust which counteracts the added mass inertia. Second, the motion of the shrinking wall acts similar to suction on a static wall, reducing separation and drag forces in a viscous fluid, but that this effects depends on the rate of size change. Third, using a combination of these two features it is possible to initially load the fluid with kinetic energy when heavy and bluff and then recover that energy when streamlined and light, enabling ultra-fast accelerations. As a notable example, these mechanisms allow a shrinking spheroid rocket in a heavy inviscid fluid to achieve speeds greater than an identical rocket in the vacuum of space. Southampton Marine and Maritime Institute.

  3. Dielectric elastomer actuators for octopus inspired suction cups.

    PubMed

    Follador, M; Tramacere, F; Mazzolai, B

    2014-09-25

    Suction cups are often found in nature as attachment strategy in water. Nevertheless, the application of the artificial counterpart is limited by the dimension of the actuators and their usability in wet conditions. A novel design for the development of a suction cup inspired by octopus suckers is presented. The main focus of this research was on the modelling and characterization of the actuation unit, and a first prototype of the suction cup was realized as a proof of concept. The actuation of the suction cup is based on dielectric elastomer actuators. The presented device works in a wet environment, has an integrated actuation system, and is soft. The dimensions of the artificial suction cups are comparable to proximal octopus suckers, and the attachment mechanism is similar to the biological counterpart. The design approach proposed for the actuator allows the definition of the parameters for its development and for obtaining a desired pressure in water. The fabricated actuator is able to produce up to 6 kPa of pressure in water, reaching the maximum pressure in less than 300 ms.

  4. Octopus: A Design Methodology for Motion Capture Wearables.

    PubMed

    Marin, Javier; Blanco, Teresa; Marin, Jose J

    2017-08-15

    Human motion capture (MoCap) is widely recognised for its usefulness and application in different fields, such as health, sports, and leisure; therefore, its inclusion in current wearables (MoCap-wearables) is increasing, and it may be very useful in a context of intelligent objects interconnected with each other and to the cloud in the Internet of Things (IoT). However, capturing human movement adequately requires addressing difficult-to-satisfy requirements, which means that the applications that are possible with this technology are held back by a series of accessibility barriers, some technological and some regarding usability. To overcome these barriers and generate products with greater wearability that are more efficient and accessible, factors are compiled through a review of publications and market research. The result of this analysis is a design methodology called Octopus, which ranks these factors and schematises them. Octopus provides a tool that can help define design requirements for multidisciplinary teams, generating a common framework and offering a new method of communication between them.

  5. Energy balance and cold adaptation in the octopus Pareledone charcoti.

    PubMed

    Daly; Peck

    2000-03-15

    A complete energy balance equation is calculated for the Antarctic octopus Pareledone charcoti at 0 degrees C. Energy used in respiration, growth, and excretion of nitrogenous and faecal waste, was recorded along with the total consumption of energy through food, for three specimens of P. charcoti (live weights: 73, 51 and 29 g). Growth rates were very slow for cephalopods, with a mean daily increase in body weight of only 0.11%. Assimilation efficiencies were high, between 95.4 and 97.0%, which is consistent with previous work on octopods. The respiration rate in P. charcoti was low, with a mean of 2.45 mg O(2) h(-1) for a standard animal of 150 g wet mass at 0 degrees C. In the North Sea octopus Eledone cirrhosa, respiration rates of 9.79 mg O(2) h(-1) at 11.5 degrees C and 4.47 mg O(2) h(-1) at 4.5 degrees C for a standard animal of 150 g wet mass were recorded. Respiration rates between P. charcoti and E. cirrhosa were compared using a combined Q(10) value between P. charcoti at 0 degrees C and E. cirrhosa at 4.5 degrees C. This suggests that P. charcoti are respiring at a level predicted by E. cirrhosa rates at 4.5 and 11.5 degrees C extrapolated to 0 degrees C along the curve Q(10)=3, with no evidence of metabolic compensation for low temperature.

  6. Distribution of three retinal proteins in developing octopus photoreceptors.

    PubMed

    Aguilar, L; Yanez, E; Flores, A; Robles, L J

    1993-06-01

    The expression of proteins unique to plasma membrane domains of developing photoreceptors is used as a marker for retinal differentiation in vertebrates. Invertebrate photoreceptors are also compartmentalized, but little information is available on the development of these compartments or the expression of retinal proteins specific to these cellular regions. Using routine electron microscopy techniques, we have made observations on the formation of photoreceptor organelles, including myeloid bodies and rhabdomeres, in embryonic octopus eyes from an early stage in development through hatching. Immunocytochemical experiments on the embryos demonstrate a timed expression of three retinal proteins during development, and the early separation of the octopus photoreceptor plasma membrane into distinct domains. Using polyclonal antibodies for opsin, retinochrome and retinal binding protein we have shown that opsin appears first and is confined to the distal end of the photoreceptor that will eventually differentiate into rhabdomeres. This membrane domain is separated from the proximal/inner segment plasma membrane by a septate junction. Retinochrome is expressed later when the myeloid bodies appear in the inner segments, and retinal binding protein is apparently not synthesized until sometime after hatching. These results suggest that, in the cephalopod retina, protein components of the retinoid cycling apparatus appear in a specific developmental sequence during the differentiation of this tissue.

  7. Crystal structure of a functional unit from Octopus hemocyanin.

    PubMed

    Cuff, M E; Miller, K I; van Holde, K E; Hendrickson, W A

    1998-05-15

    Hemocyanins are giant oxygen transport proteins found in many arthropods and molluscs. Freely dissolved in the hemolymph, they are multisubunit proteins that contain many copies of the active site, a copper atom pair that reversibly binds oxygen. Octopus hemocyanin is composed of ten subunits, each of which contain seven oxygen-binding "functional units". The carboxyl-terminal 47 kDa functional unit, Odg, is a proteolytic isolate that binds oxygen reversibly while exhibiting slight Bohr and magnesium ion effects. In this work we present the X-ray structure determination and analysis of Odg at 2.3 A resolution. Odg has two structural domains: a largely alpha-helical copper binding domain, and a five-stranded anti-parallel beta-sandwich with the jelly roll topology found in many viruses. Six histidine residues ligate the copper atoms, one of which is involved in a thioether bridge. The results show that the hemocyanin from the mollusc and that from the arthropod have distinct tertiary folds in addition to the long recognized differences in their quaternary structures. Nonetheless, a comparison of Octopus and horseshoe crab hemocyanin reveals a similar active site, in a striking example of perhaps both convergent and divergent evolution.

  8. Octopus: A Design Methodology for Motion Capture Wearables

    PubMed Central

    2017-01-01

    Human motion capture (MoCap) is widely recognised for its usefulness and application in different fields, such as health, sports, and leisure; therefore, its inclusion in current wearables (MoCap-wearables) is increasing, and it may be very useful in a context of intelligent objects interconnected with each other and to the cloud in the Internet of Things (IoT). However, capturing human movement adequately requires addressing difficult-to-satisfy requirements, which means that the applications that are possible with this technology are held back by a series of accessibility barriers, some technological and some regarding usability. To overcome these barriers and generate products with greater wearability that are more efficient and accessible, factors are compiled through a review of publications and market research. The result of this analysis is a design methodology called Octopus, which ranks these factors and schematises them. Octopus provides a tool that can help define design requirements for multidisciplinary teams, generating a common framework and offering a new method of communication between them. PMID:28809786

  9. Melatonin in octopus (Octopus vulgaris): tissue distribution, daily changes and relation with serotonin and its acid metabolite.

    PubMed

    Muñoz, José L P; López Patiño, Marcos A; Hermosilla, Consuelo; Conde-Sieira, Marta; Soengas, José L; Rocha, Francisco; Míguez, Jesús M

    2011-08-01

    Information regarding melatonin production in molluscs is very limited. In this study the presence and daily fluctuations of melatonin levels were investigated in hemolymph, retina and nervous system-related structures in the cephalopod Octopus vulgaris. Adult animals were maintained in captivity under natural photoperiod and killed at different times in a regular daily cycle. Levels of melatonin, serotonin (5-HT) and its acid metabolite (5-hydroxyindole acetic acid, 5-HIAA) in the hemolymph, retina, optic lobe, and cerebral ganglion were assayed by HPLC. Melatonin content fluctuated rhythmically in the retina and hemolymph, peaking at night. In the retina, but not in the other neural tissues, the rhythm was opposite to that of 5-HT, which displayed basal levels at night. Also, 5-HIAA levels in the retina were higher during the night, supporting that rhythmic melatonin production could be linked to diurnal changes in 5-HT degradation. The high levels of melatonin found in the retina point to it as the major source of melatonin in octopus; in addition, a large variation of melatonin content was found in the optic lobe with maximal values at night. All these data suggest that melatonin might play a role in the transduction of the light-dark cycle information for adjustment of rhythmic physiological events in cephalopods.

  10. Sperm-attractant peptide influences the spermatozoa swimming behavior in internal fertilization in Octopus vulgaris.

    PubMed

    De Lisa, Emilia; Salzano, Anna Maria; Moccia, Francesco; Scaloni, Andrea; Di Cosmo, Anna

    2013-06-15

    Marine invertebrates exhibit both chemokinesis and chemotaxis phenomena, induced in most cases by the release of water-borne peptides or pheromones. In mollusks, several peptides released during egg-laying improve both male attraction and mating. Unlike other cephalopods, Octopus vulgaris adopts an indirect internal fertilization strategy. We here report on the identification and characterization of a chemoattractant peptide isolated from mature eggs of octopus females. Using two-chamber and time-lapse microscopy assays, we demonstrate that this bioactive peptide is able to increase sperm motility and induce chemotaxis by changing the octopus spermatozoa swimming behavior in a dose-dependent manner. We also provide evidence that chemotaxis in the octopus requires the presence of extracellular calcium and membrane protein phophorylation at tyrosine. This study is the first report on a sperm-activating factor in a non-free-spawning marine animal.

  11. A "Mimic Octopus" in the Atlantic: Flatfish mimicry and camouflage by Macrotritopus defilippi.

    PubMed

    Hanlon, Roger T; Watson, Anya C; Barbosa, Alexandra

    2010-02-01

    The sand-dwelling octopus Macrotritopus defilippi was filmed or photographed in five Caribbean locations mimicking the swimming behavior (posture, style, speed, duration) and coloration of the common, sand-dwelling flounder Bothus lunatus. Each species was exceptionally well camouflaged when stationary, and details of camouflaging techniques are described for M. defilippi. Octopuses implemented flounder mimicry only during swimming, when their movement would give away camouflage in this open sandy habitat. Thus, both camouflage and fish mimicry were used by the octopuses as a primary defense against visual predators. This is the first documentation of flounder mimicry by an Atlantic octopus, and only the fourth convincing case of mimicry for cephalopods, a taxon renowned for its polyphenism that is implemented mainly by neurally controlled skin patterning, but also-as shown here-by their soft flexible bodies.

  12. Molecular phylogeny of the benthic shallow-water octopuses (Cephalopoda: Octopodinae).

    PubMed

    Guzik, Michelle T; Norman, Mark D; Crozier, Ross H

    2005-10-01

    Octopus has been regarded as a "catch all" genus, yet its monophyly is questionable and has been untested. We inferred a broad-scale phylogeny of the benthic shallow-water octopuses (subfamily Octopodinae) using amino acid sequences of two mitochondrial DNA genes: Cytochrome oxidase subunit III and Cytochrome b apoenzyme, and the nuclear DNA gene Elongation Factor-1alpha. Sequence data were obtained from 26 Octopus species and from four related genera. Maximum likelihood and Bayesian approaches were implemented to estimate the phylogeny, and non-parametric bootstrapping was used to verify confidence for Bayesian topologies. Phylogenetic relationships between closely related species were generally well resolved, and groups delineated, but the genes did not resolve deep divergences well. The phylogenies indicated strongly that Octopus is not monophyletic, but several monophyletic groups were identified within the genus. It is therefore clear that octopodid systematics requires major revision.

  13. The octopus: a model for a comparative analysis of the evolution of learning and memory mechanisms.

    PubMed

    Hochner, Binyamin; Shomrat, Tal; Fiorito, Graziano

    2006-06-01

    Comparative analysis of brain function in invertebrates with sophisticated behaviors, such as the octopus, may advance our understanding of the evolution of the neural processes that mediate complex behaviors. Until the last few years, this approach was infeasible due to the lack of neurophysiological tools for testing the neural circuits mediating learning and memory in the brains of octopus and other cephalopods. Now, for the first time, the adaptation of modern neurophysiological methods to the study of the central nervous system of the octopus allows this avenue of research. The emerging results suggest that a convergent evolutionary process has led to the selection of vertebrate-like neural organization and activity-dependent long-term synaptic plasticity. As octopuses and vertebrates are very remote phylogenetically, this convergence suggests the importance of the shared properties for the mediation of learning and memory.

  14. Arm injury produces long-term behavioral and neural hypersensitivity in octopus.

    PubMed

    Alupay, Jean S; Hadjisolomou, Stavros P; Crook, Robyn J

    2014-01-13

    Cephalopod molluscs are the most neurally and behaviorally complex invertebrates, with brains rivaling those of some vertebrates in size and complexity. This has fostered the opinion that cephalopods, particularly octopuses, may experience vertebrate-like pain when injured. However, it is not known whether octopuses possess nociceptors or if their somatic sensory neurons exhibit sensitization after injury. Here we show that the octopus Abdopus aculeatus expresses nocifensive behaviors including arm autotomy, and displays marked neural hyperexcitability both in injured and uninjured arms for at least 24h after injury. These findings do not demonstrate that octopuses experience pain-like states; instead they add to the minimal existing literature on how cephalopods receive, process, and integrate noxious sensory information, potentially informing and refining regulations governing use of cephalopods in scientific research.

  15. Camouflaging in a Complex Environment—Octopuses Use Specific Features of Their Surroundings for Background Matching

    PubMed Central

    Josef, Noam; Amodio, Piero; Fiorito, Graziano; Shashar, Nadav

    2012-01-01

    Living under intense predation pressure, octopuses evolved an effective and impressive camouflaging ability that exploits features of their surroundings to enable them to “blend in.” To achieve such background matching, an animal may use general resemblance and reproduce characteristics of its entire surroundings, or it may imitate a specific object in its immediate environment. Using image analysis algorithms, we examined correlations between octopuses and their backgrounds. Field experiments show that when camouflaging, Octopus cyanea and O. vulgaris base their body patterns on selected features of nearby objects rather than attempting to match a large field of view. Such an approach enables the octopus to camouflage in partly occluded environments and to solve the problem of differences in appearance as a function of the viewing inclination of the observer. PMID:22649542

  16. Camouflaging in a complex environment--octopuses use specific features of their surroundings for background matching.

    PubMed

    Josef, Noam; Amodio, Piero; Fiorito, Graziano; Shashar, Nadav

    2012-01-01

    Living under intense predation pressure, octopuses evolved an effective and impressive camouflaging ability that exploits features of their surroundings to enable them to "blend in." To achieve such background matching, an animal may use general resemblance and reproduce characteristics of its entire surroundings, or it may imitate a specific object in its immediate environment. Using image analysis algorithms, we examined correlations between octopuses and their backgrounds. Field experiments show that when camouflaging, Octopus cyanea and O. vulgaris base their body patterns on selected features of nearby objects rather than attempting to match a large field of view. Such an approach enables the octopus to camouflage in partly occluded environments and to solve the problem of differences in appearance as a function of the viewing inclination of the observer.

  17. Preservation of shelf life of pota and octopus in chilled storage under controlled atmospheres.

    PubMed

    Ruiz-Capillas, C; Moral, A; Morales, J; Montero, P

    2002-01-01

    Whole ungutted pota and octopus were stored in bulk in stainless steel refrigerated containers under controlled atmospheres. In order to evaluate the effectiveness of this treatment, physicochemical tests (pH, trimethylamine nitrogen, total volatile basic nitrogen, 2-thiobarbituric acid) and sensory assessments (inspection) were done. For both pota and octopus, the control lot had the highest physicochemical values and the lowest sensory values, and of the two assayed atmospheres, the 60/15/25% atmosphere (CO2/O2/N2) had the best physicochemical results. pH, trimethylamine nitrogen, and total volatile basic nitrogen levels were lower (P < or = 0.05) in octopus than in pota, and the inspection results were significantly (P < or = 0.05) higher. However, the octopus had a higher 2-thiobarbituric acid index than the pota. Therefore, the application of controlled atmospheres on these cephalopods during chilled bulk storage considerably increases their shelf life.

  18. Results of a new OCTOPUS'' ECR ion source at 6. 4 GHz

    SciTech Connect

    Dupont, C.; Jongen, Y. ); Arakawa, K.; Yokota, W. ); Satoh, T.; Tachikawa, T. )

    1990-01-01

    The first OCTOPUS electron cyclstron resonance (ECR) multicharged heavy ion source was built in 1985 at the Centre de Recherches du Cyclotron of the University of Louvain (Belgium). This first source used an ECR frequency of 14.3 GHz in the injector stage and 8.5 GHz in the main confinement stage. A new OCTOPUS source has now been built for a new cyclotron to be installed at the Japan Atomic Energy Research Institute (JAERI). The design of this new OCTOPUS source is identical to the first OCTOPUS source, but uses an ECR frequency of 6.4 GHz in the main confinement stage. The experimental results are described, and a comparison is made between the two sources. However, the available data does not allow any clear conclusion to be drawn on frequency scaling.

  19. Lesions of the vertical lobe impair visual discrimination learning by observation in Octopus vulgaris.

    PubMed

    Fiorito, G; Chichery, R

    1995-06-09

    We investigated whether lesions of the vertical lobe of the supraesophageal nervous mass of Octopus vulgaris impair discrimination learning acquired by observation of conspecific behavior. When tested alone, observer octopuses with about 50% of the vertical lobe removed showed a deficit in their learning by observation performance. The level of learning improved 24 h after the observational phase, when observer Octopus vulgaris showed a visual discriminatory performance significantly in agreement with the observed one. Control animals that had no brain tissue removed, did not show any impairment in the discriminative performance they had acquired vicariously. Removal of the vertical lobe of the octopus 'brain' has been reported to induce learning and memory deficits of visual discrimination in direct learning by conditioning experiments. Our findings support the conclusion that the removal of such brain center impairs short-term recall, but does not impair acquisition nor retention of 'observational' long-term memory.

  20. Analysis of 3D models of octopus estrogen receptor with estradiol: evidence for steric clashes that prevent estrogen binding.

    PubMed

    Baker, Michael E; Chandsawangbhuwana, Charlie

    2007-09-28

    Relatives of the vertebrate estrogen receptor (ER) are found in Aplysia californica, Octopus vulgaris, Thais clavigera, and Marisa cornuarietis. Unlike vertebrate ERs, invertebrate ERs are constitutively active and do not bind estradiol. To investigate the molecular basis of the absence of estrogen binding, we constructed a 3D model of the putative steroid-binding domain on octopus ER. Our 3D model indicates that binding of estradiol to octopus ER is prevented by steric clashes between estradiol and amino acids in the steroid-binding pocket. In this respect, octopus ER resembles vertebrate estrogen-related receptors (ERR), which have a ligand-binding pocket that cannot accommodate estradiol. Like ERR, octopus ER also may have the activation function 2 domain (AF2) in a configuration that can bind to coactivators in the absence of estrogens, which would explain constitutive activity of octopus ER.

  1. Self-recognition mechanism between skin and suckers prevents octopus arms from interfering with each other.

    PubMed

    Nesher, Nir; Levy, Guy; Grasso, Frank W; Hochner, Binyamin

    2014-06-02

    Controlling movements of flexible arms is a challenging task for the octopus because of the virtually infinite number of degrees of freedom (DOFs) [1, 2]. Octopuses simplify this control by using stereotypical motion patterns that reduce the DOFs, in the control space, to a workable few [2]. These movements are triggered by the brain and are generated by motor programs embedded in the peripheral neuromuscular system of the arm [3-5]. The hundreds of suckers along each arm have a tendency to stick to almost any object they contact [6-9]. The existence of this reflex could pose significant problems with unplanned interactions between the arms if not appropriately managed. This problem is likely to be accentuated because it is accepted that octopuses are "not aware of their arms" [10-14]. Here we report of a self-recognition mechanism that has a novel role in motor control, restraining the arms from interfering with each other. We show that the suckers of amputated arms never attach to octopus skin because a chemical in the skin inhibits the attachment reflex of the suckers. The peripheral mechanism appears to be overridden by central control because, in contrast to amputated arms, behaving octopuses sometime grab amputated arms. Surprisingly, octopuses seem to identify their own amputated arms, as they treat arms of other octopuses like food more often than their own. This self-recognition mechanism is a novel peripheral component in the embodied organization of the adaptive interactions between the octopus's brain, body, and environment [15, 16].

  2. Abnormal mortality of octopus after a storm water event: Accumulated lead and lead isotopes as fingerprints.

    PubMed

    Raimundo, J; Ruano, F; Pereira, J; Mil-Homens, M; Brito, P; Vale, C; Caetano, M

    2017-03-01

    Octopus vulgaris is a sedentary organism that inhabits coastal waters being exposed to anthropogenic compounds. Lead concentration in coastal environments reflects many processes and activities namely weathering, industrial and domestic discharges, and atmospheric deposition. Since lead isotopic composition is little affected by kinetic processes occurring between source and sink, its signature has been used to identify different Pb sources. After a short-term heavy rainfall, hundreds of octopus appeared dead in two Portuguese coastal areas. Histopathology and Pb levels and its stable isotopes were determined in tissues, such as digestive gland, of stranded octopus and compared to alive specimens, sediments and runoff material from the same areas. Histology results showed severe damage in stranded octopus tissues suggesting that death was probably associated to multiple organ failure linked to hypertrophy and exudates input. In addition, Pb in stranded specimens reach concentrations up to one order of magnitude above the levels reported for alive octopus. Pb isotopic signatures in stranded organisms were closer to runoff material pointing to a similar origin of Pb. In summary, the results in this study showed that a short-term runoff event might change abruptly the salinity leading to the disruption of the osmoregulation function of octopus and consequently leading to its death. The analyses of stable isotopic Pb signature in octopus tissues corroborate these results and points to a change in the Pb source due to runoff after the storm water event. Pb stable isotopes in octopus proved to be an adequate tool to confirm the cause of death and linking it to the environment conditions.

  3. Lack of effect of tetrodotoxin and of an extract from the posterior salivary gland of the blue-ringed octopus following injection into the octopus and following application to its brachial nerve.

    PubMed

    Flachsenberger, W; Kerr, D I

    1985-01-01

    Lack of effect of tetrodotoxin and of an extract from the posterior salivary gland of the blue-ringed octopus following injection into the octopus and following application to its brachial nerve. Toxicon 23, 997-999, 1985. Injections of the blue-ringed octopus salivary gland extract and tetrodotoxin into the blue-ringed octopus have no ill-effect on the animals. Similarly, in vitro nerve preparations from the animal were not affected by these materials although they are both extremely potent on bioelectrically excitable preparations from other species.

  4. Resonance Raman Studies of Bovine and OCTOPUS Visual Pigments

    NASA Astrophysics Data System (ADS)

    Huang, Liewen

    1995-01-01

    We have regenerated bovine and octopus visual pigments with retinals containing isotopic labels at three positions, i.e., 8-^{13}C -11,12-D_2, 10-^{13 }C-11,12-D_2, 11- ^{13}C-11,12-D_2 , 14-^{13}C-11,12 -D_2, for the studies of bound chromophore ethylenic and Schiff base vibrational modes by resonance Raman spectroscopy. Also regenerated were octopus visual pigments with singly or doubly ^{13 }C labeled retinals, i.e., 9-^ {13}C, 10,11-^{13 }C_2, 12,13- ^{13}C_2, 13-^{13}C, 14,15- ^{13}C_2, 14,15-^{13}C_2 -ND, for the studies of vibrational modes in the fingerprint region. We have analyzed the resonance Raman spectra based upon the observation of the response of individual bands in the spectrum of rhodopsin, isorhodopsin, or bathorhodopsin to a particular label. The observed peaks in the fingerprint and ethylenic regions have been tentatively assigned to specific C-C and C=C stretches. We have also studied a model retinal protonated Schiff base analog and its isotopically labeled derivatives as well as calculations using ab initio methods. Based on the vibrational analysis, new criteria to determine the Schiff base C=N configuration from Raman spectroscopy have been developed, and the C=N configuration in octopus rhodopsin, isorhodopsin and bathorhodopsin has been determined. We have continued the resonance Raman study of the Schiff base hydrogen/deuterium exchange for rhodopsin and bacteriorhodopsin by employing the continuous-flow experiment. The exchange of a deuteron on the Schiff base with a proton is very fast, with half-times of 6.9 +/- 0.9 and 1.3 +/- 0.3 ms for rhodopsin and bacteriorhodopsin, respectively, faster than the proton-deuteron exchange rate of a protonated Schiff base in aqueous solution (16 +/- 2 ms). This anomalous result can be understand if a structural water molecule (or molecules) is present next to the protonated Schiff base in the two pigments.

  5. Octopus vulgaris uses visual information to determine the location of its arm.

    PubMed

    Gutnick, Tamar; Byrne, Ruth A; Hochner, Binyamin; Kuba, Michael

    2011-03-22

    Octopuses are intelligent, soft-bodied animals with keen senses that perform reliably in a variety of visual and tactile learning tasks. However, researchers have found them disappointing in that they consistently fail in operant tasks that require them to combine central nervous system reward information with visual and peripheral knowledge of the location of their arms. Wells claimed that in order to filter and integrate an abundance of multisensory inputs that might inform the animal of the position of a single arm, octopuses would need an exceptional computing mechanism, and "There is no evidence that such a system exists in Octopus, or in any other soft bodied animal." Recent electrophysiological experiments, which found no clear somatotopic organization in the higher motor centers, support this claim. We developed a three-choice maze that required an octopus to use a single arm to reach a visually marked goal compartment. Using this operant task, we show for the first time that Octopus vulgaris is capable of guiding a single arm in a complex movement to a location. Thus, we claim that octopuses can combine peripheral arm location information with visual input to control goal-directed complex movements.

  6. The use of artificial crabs for testing predatory behavior and health in the octopus.

    PubMed

    Amodio, Piero; Andrews, Paul; Salemme, Marinella; Ponte, Giovanna; Fiorito, Graziano

    2014-01-01

    The willingness of the cephalopod mollusc Octopus vulgaris to attack a live crab is traditionally used as a method to assess the overall health and welfare of octopuses in the laboratory. This method requires placing a crab in the home tank of an animal, measuring the time (latency) taken for the octopus to initiate an attack and withdrawing the crab immediately prior to capture. The same crab is commonly used to assess multiple octopuses as part of daily welfare assessment. Growing concern for the welfare of crustaceans and a review of all laboratory practices for the care and welfare of cephalopods following the inclusion of this taxon in 2010/63/EU prompted a study of the utility of an artificial crab to replace a live crab in the assessment of octopus health. On consecutive days O. vulgaris (N=21) were presented with a live, a dead or an artificial crab, and the latency to attack measured. Despite differences in the predatory performance towards the three different crab alternatives, octopuses readily attacked the artificial (and the dead) crab, showing that they can generalize and respond appropriately towards artificial prey. Researchers should consider using an artificial crab to replace the use of a live crab as part of the routine health assessment of O. vulgaris.

  7. Octopus cells of the mammalian ventral cochlear nucleus sense the rate of depolarization.

    PubMed

    Ferragamo, Michael J; Oertel, Donata

    2002-05-01

    Whole cell patch recordings in slices show that the probability of firing of action potentials in octopus cells of the ventral cochlear nucleus depends on the dynamic properties of depolarization. Octopus cells fired only when the rate of rise of a depolarization exceeded a threshold value that varied between 5 and 15 mV/ms among cells. The threshold rate of rise was independent of whether depolarizations were evoked synaptically or by the intracellular injection of current. Previous work showed that octopus cells are contacted by many auditory nerve fibers, each providing less than 1-mV depolarization. Summation of synaptic input from multiple fibers is required for an octopus cell to reach threshold. In firing only when synaptic depolarization exceeds a threshold rate, octopus cells fire selectively when synaptic input is sufficiently large and synchronized for the small, brief unitary excitatory postsynaptic potentials (EPSPs) to sum to produce a rapidly rising depolarization. The sensitivity to rate of depolarization is governed by a low-threshold, alpha-dendrotoxin-sensitive potassium conductance (g(KL)). This conductance also shapes the peaks of action potentials, contributing to the precision in their timing. Firing in neighboring T stellate cells depends much less strongly on the rate of rise. They lack strong alpha-dendrotoxin-sensitive conductances. Octopus cells appear to be specialized to detect synchronization in the activation of groups of auditory nerve fibers, a common pattern in responses to natural sounds, and convey its occurrence with temporal precision.

  8. Cloning of Octopus cephalotocin receptor, a member of the oxytocin/vasopressin superfamily.

    PubMed

    Kanda, Atsuhiro; Takuwa-Kuroda, Kyoko; Iwakoshi-Ukena, Eiko; Furukawa, Yasuo; Matsushima, Osamu; Minakata, Hiroyuki

    2003-11-01

    We reported that the common octopus, Octopus vulgaris, in common with vertebrates, possesses two members of the oxytocin/vasopressin superfamily: octopressin (OP) and cephalotocin (CT). This was the first observation of its kind in invertebrates. As OP and CT have different biological activities, the presence of specific receptors has been proposed. We cloned the cDNA of an orphan receptor from Octopus brain and found it to encode a polypeptide of 397 amino acids that displays sequences characteristic of G-protein coupled receptors. The orphan receptor showed high homology to receptors of the oxytocin/vasopressin superfamily and seemed to conserve the agonist-binding pocket common to the oxytocin and vasopressin receptors. Xenopus oocytes that express the orphan receptor responded to the application of CT by an induction of membrane Cl(-) currents coupled to the inositol phosphate/Ca(2+) pathway. OP and the other members of the oxytocin/vasopressin superfamily did not activate this receptor. HPLC fractionation of the Octopus brain extract combined with an oocyte assay yielded a single substance that was identical to CT. On the basis of these results, we conclude that the cloned receptor is the CT receptor (CTR). Expression of CTR mRNA in Octopus was detected in the central and the peripheral nervous systems, the pancreas, the oviduct and the ovary. This receptor may mediate physiological functions of CT in Octopus such as neurotransmission, reproduction and metabolism.

  9. Cytochalasin D blocks touch learning in Octopus vulgaris.

    PubMed

    Robertson, J D

    1994-10-22

    Supraoesophageal lobes in 11 specimens of Octopus vulgaris were split sagitally into two symmetrical halves and isolated by a thin inert mica barrier. Each half-brain is known to control the four arms on its side of the animal and to be able to learn opposite touch paradigms mediated by its four arms. Powdered cytochalasin D was applied directly in each animal to the subfrontal lobe of one half-brain, and both half-brains were then trained to opposite touch paradigms. The cytochalasin treated half-brains could not learn either touch paradigm whereas the control half-brains learned readily. In another set of four animals, cytochalasin D was similarly applied but to the vertical lobe of one half-brain. In this case all the half-brains learned the touch paradigm.

  10. Oxidation of Octopus vulgaris hemocyanin by nitrogen oxides

    SciTech Connect

    Salvato, B.; Giacometti, G.M.; Beltramini, M.; Zilio, F.; Giacometti, G.; Magliozzo, R.S.; Peisach, J.

    1989-01-24

    The reaction of Octopus vulgaris hemocyanin with nitrite was studied under a variety of conditions in which the green half-met derivative is formed. Analytical evidence shows that the amount of chemically detectable nitrite in various samples of the derivative is not proportional to the cupric copper detected by EPR. The kinetics of oxidation of hemocyanin as a function of protein concentration and pH, in the presence of nitrite and ascorbate, is consistent with a scheme in which NO/sub 2/ is the reactive oxidant. We suggest that the green half-methemocyanin contains a metal center with one cuprous and one cupric copper without an exogenous nitrogen oxide ligand.

  11. Control of octopus arm extension by a peripheral motor program.

    PubMed

    Sumbre, G; Gutfreund, Y; Fiorito, G; Flash, T; Hochner, B

    2001-09-07

    For goal-directed arm movements, the nervous system generates a sequence of motor commands that bring the arm toward the target. Control of the octopus arm is especially complex because the arm can be moved in any direction, with a virtually infinite number of degrees of freedom. Here we show that arm extensions can be evoked mechanically or electrically in arms whose connection with the brain has been severed. These extensions show kinematic features that are almost identical to normal behavior, suggesting that the basic motor program for voluntary movement is embedded within the neural circuitry of the arm itself. Such peripheral motor programs represent considerable simplification in the motor control of this highly redundant appendage.

  12. Comparative morphology of changeable skin papillae in octopus and cuttlefish.

    PubMed

    Allen, Justine J; Bell, George R R; Kuzirian, Alan M; Velankar, Sachin S; Hanlon, Roger T

    2014-04-01

    A major component of cephalopod adaptive camouflage behavior has rarely been studied: their ability to change the three-dimensionality of their skin by morphing their malleable dermal papillae. Recent work has established that simple, conical papillae in cuttlefish (Sepia officinalis) function as muscular hydrostats; that is, the muscles that extend a papilla also provide its structural support. We used brightfield and scanning electron microscopy to investigate and compare the functional morphology of nine types of papillae of different shapes, sizes and complexity in six species: S. officinalis small dorsal papillae, Octopus vulgaris small dorsal and ventral eye papillae, Macrotritopus defilippi dorsal eye papillae, Abdopus aculeatus major mantle papillae, O. bimaculoides arm, minor mantle, and dorsal eye papillae, and S. apama face ridge papillae. Most papillae have two sets of muscles responsible for extension: circular dermal erector muscles arranged in a concentric pattern to lift the papilla away from the body surface and horizontal dermal erector muscles to pull the papilla's perimeter toward its core and determine shape. A third set of muscles, retractors, appears to be responsible for pulling a papilla's apex down toward the body surface while stretching out its base. Connective tissue infiltrated with mucopolysaccharides assists with structural support. S. apama face ridge papillae are different: the contraction of erector muscles perpendicular to the ridge causes overlying tissues to buckle. In this case, mucopolysaccharide-rich connective tissue provides structural support. These six species possess changeable papillae that are diverse in size and shape, yet with one exception they share somewhat similar functional morphologies. Future research on papilla morphology, biomechanics and neural control in the many unexamined species of octopus and cuttlefish may uncover new principles of actuation in soft, flexible tissue.

  13. Rho GTPases regulate rhabdom morphology in octopus photoreceptors.

    PubMed

    Miller, Aria M; Ramirez, Teresa; Zuniga, Freddi I; Ochoa, Gina H; Gray, Shaunte; Kelly, Shannon D; Matsumoto, Brian; Robles, Laura J

    2005-01-01

    In the cephalopod retina, light/dark adaptation is accompanied by a decrease/increase in rhabdom size and redistribution of rhodopsin and retinochrome. Rearrangements in the actin cytoskeleton probably govern changes in rhabdom size by regulating the degradation/formation of rhabdomere microvilli. Photopigment movements may be directed by microtubules present in the outer segment core cytoplasm. We believe that rhodopsin activation by light stimulates Rho and Rac signaling pathways, affecting these cytoskeletal systems and their possible functions in controlling rhabdom morphology and protein movements. In this study, we localized cytoskeletal and signaling proteins in octopus photoreceptors to determine their concurrence between the lighting conditions. We used toxin B from Clostridium difficile to inhibit the activity of Rho/Rac and observed its effect on the location of signaling proteins and actin and tubulin. In both lighting conditions, we found Rho in specific sets of juxtaposed rhabdomeres in embryonic and adult retinas. In the light, Rho and actin were localized along the length of the rhabdomere, but, in the dark, both proteins were absent from a space beneath the inner limiting membrane. Rac colocalized with tubulin in the outer segment core cytoplasm and, like Rho, the two proteins were also absent beneath the inner limiting membrane in the dark. The distribution of actin and Rho was affected by toxin B and, in dark-adapted retinas, actin and Rho distribution was similar to that observed in the light. Our results suggest that the Rho/Rac GTPases are candidates for the regulation of rhabdomere size and protein movements in light-dark-adapted octopus photoreceptors.

  14. Novel evolutionary lineages of the invertebrate oxytocin/vasopressin superfamily peptides and their receptors in the common octopus (Octopus vulgaris)

    PubMed Central

    Kanda, Atsuhiro; Satake, Honoo; Kawada, Tsuyoshi; Minakata, Hiroyuki

    2004-01-01

    The common octopus, Octopus vulgaris, is the first invertebrate species that was shown to possess two oxytocin/vasopressin (OT/VP) superfamily peptides, octopressin (OP) and cephalotocin (CT). Previously, we cloned a GPCR (G-protein-coupled receptor) specific to CT [CTR1 (CT receptor 1)]. In the present study, we have identified an additional CTR, CTR2, and a novel OP receptor, OPR. Both CTR2 and OPR include domains and motifs typical of GPCRs, and the intron– exon structures are in accord with those of OT/VP receptor genes. CTR2 and OPR expressed in Xenopus oocytes induced calcium-mediated inward chloride current in a CT- and OP-specific manner respectively. Several regions and residues, which are requisite for binding of the vertebrate OT/VP receptor family with their ligands, are highly conserved in CTRs, but not in OPR. These different sequences between CTRs and OPR, as well as the amino acid residues of OP and CT at positions 2–5, were presumed to play crucial roles in the binding selectivity to their receptors, whereas the difference in the polarity of OT/VP family peptide residues at position 8 confers OT and VP with the binding specificity in vertebrates. CTR2 mRNA was present in various peripheral tissues, and OPR mRNA was detected in both the nervous system and peripheral tissues. Our findings suggest that the CT and OP genes, similar to the OT/VP family, evolved through duplication, but the ligand–receptor selectivity were established through different evolutionary lineages from those of their vertebrate counterparts. PMID:15504101

  15. Beak measurements of octopus ( Octopus variabilis) in Jiaozhou Bay and their use in size and biomass estimation

    NASA Astrophysics Data System (ADS)

    Xue, Ying; Ren, Yiping; Meng, Wenrong; Li, Long; Mao, Xia; Han, Dongyan; Ma, Qiuyun

    2013-09-01

    Cephalopods play key roles in global marine ecosystems as both predators and preys. Regressive estimation of original size and weight of cephalopod from beak measurements is a powerful tool of interrogating the feeding ecology of predators at higher trophic levels. In this study, regressive relationships among beak measurements and body length and weight were determined for an octopus species ( Octopus variabilis), an important endemic cephalopod species in the northwest Pacific Ocean. A total of 193 individuals (63 males and 130 females) were collected at a monthly interval from Jiaozhou Bay, China. Regressive relationships among 6 beak measurements (upper hood length, UHL; upper crest length, UCL; lower hood length, LHL; lower crest length, LCL; and upper and lower beak weights) and mantle length (ML), total length (TL) and body weight (W) were determined. Results showed that the relationships between beak size and TL and beak size and ML were linearly regressive, while those between beak size and W fitted a power function model. LHL and UCL were the most useful measurements for estimating the size and biomass of O. variabilis. The relationships among beak measurements and body length (either ML or TL) were not significantly different between two sexes; while those among several beak measurements (UHL, LHL and LBW) and body weight (W) were sexually different. Since male individuals of this species have a slightly greater body weight distribution than female individuals, the body weight was not an appropriate measurement for estimating size and biomass, especially when the sex of individuals in the stomachs of predators was unknown. These relationships provided essential information for future use in size and biomass estimation of O. variabilis, as well as the estimation of predator/prey size ratios in the diet of top predators.

  16. Ultrastructure and immunocytochemical characteristics of cells in the octopus cell area of the rat cochlear nucleus: comparison with multipolar cells.

    PubMed

    Alibardi, Lorenzo

    2003-01-01

    Cells in the octopus cell area of the rat ventral cochlear nucleus have been connected to the monaural interpretation of spectral patterns of sound such as those derived from speech. This is possible by their fast onset of firing after each octopus cell and its dendrites have been contacted by many auditory fibres carrying different frequencies. The cytological characteristics that make these large cells able to perform such a function have been studied with ultrastructural immunocytochemistry for glycine, GABA and glutamate, and compared to that of other multipolar neurons of other regions of the ventral cochlear nucleus. Cells in the octopus cell area have an ultrastructure similar to large-giant D-multipolar neurons present in other areas of the cochlear nucleus, from which they differ by the presence of a larger excitatory axo-somatic synaptic input and larger mitochondria. Octopus cells are glycine and GABA negative, and glutamate positive with different degree. Large octopus cells receive more axo-somatic boutons than smaller octopus cells. Fusiform octopus cells are found sparsely within the intermediate acoustic striae. These cells are large to giant excitatory neurons (23-35 microm) with 62-85% of their irregular perimeter covered with large axo-somatic synaptic boutons. Most boutons contain round vesicles and are glycine and GABA negative but glutamate positive. The latter excitatory boutons represent about 70% of the input to octopus cells. Glycine positive boutons with flat and pleomorphic vesicles account for 9-10% of the input while GABA-ergic boutons with pleomorphic vesicles represent about 20% of the synaptic input. Other few, multipolar cells within the rat octopus cell area are surrounded by more inhibitory than excitatory terminals which contain flat and pleomorphic vesicles, a feature distinctive from that of true octopus cells. The latter resemble multipolar cells seen outside the octopus cell area that project to the contralateral inferior

  17. Detection of synchrony in the activity of auditory nerve fibers by octopus cells of the mammalian cochlear nucleus.

    PubMed

    Oertel, D; Bal, R; Gardner, S M; Smith, P H; Joris, P X

    2000-10-24

    The anatomical and biophysical specializations of octopus cells allow them to detect the coincident firing of groups of auditory nerve fibers and to convey the precise timing of that coincidence to their targets. Octopus cells occupy a sharply defined region of the most caudal and dorsal part of the mammalian ventral cochlear nucleus. The dendrites of octopus cells cross the bundle of auditory nerve fibers just proximal to where the fibers leave the ventral and enter the dorsal cochlear nucleus, each octopus cell spanning about one-third of the tonotopic array. Octopus cells are excited by auditory nerve fibers through the activation of rapid, calcium-permeable, alpha-amino-3-hydroxy-5-methyl-4-isoxazole-propionate receptors. Synaptic responses are shaped by the unusual biophysical characteristics of octopus cells. Octopus cells have very low input resistances (about 7 M Omega), and short time constants (about 200 microsec) as a consequence of the activation at rest of a hyperpolarization-activated mixed-cation conductance and a low-threshold, depolarization-activated potassium conductance. The low input resistance causes rapid synaptic currents to generate rapid and small synaptic potentials. Summation of small synaptic potentials from many fibers is required to bring an octopus cell to threshold. Not only does the low input resistance make individual excitatory postsynaptic potentials brief so that they must be generated within 1 msec to sum but also the voltage-sensitive conductances of octopus cells prevent firing if the activation of auditory nerve inputs is not sufficiently synchronous and depolarization is not sufficiently rapid. In vivo in cats, octopus cells can fire rapidly and respond with exceptionally well-timed action potentials to periodic, broadband sounds such as clicks. Thus both the anatomical specializations and the biophysical specializations make octopus cells detectors of the coincident firing of their auditory nerve fiber inputs.

  18. Detection of synchrony in the activity of auditory nerve fibers by octopus cells of the mammalian cochlear nucleus

    PubMed Central

    Oertel, Donata; Bal, Ramazan; Gardner, Stephanie M.; Smith, Philip H.; Joris, Philip X.

    2000-01-01

    The anatomical and biophysical specializations of octopus cells allow them to detect the coincident firing of groups of auditory nerve fibers and to convey the precise timing of that coincidence to their targets. Octopus cells occupy a sharply defined region of the most caudal and dorsal part of the mammalian ventral cochlear nucleus. The dendrites of octopus cells cross the bundle of auditory nerve fibers just proximal to where the fibers leave the ventral and enter the dorsal cochlear nucleus, each octopus cell spanning about one-third of the tonotopic array. Octopus cells are excited by auditory nerve fibers through the activation of rapid, calcium-permeable, α-amino-3-hydroxy-5-methyl-4-isoxazole-propionate receptors. Synaptic responses are shaped by the unusual biophysical characteristics of octopus cells. Octopus cells have very low input resistances (about 7 MΩ), and short time constants (about 200 μsec) as a consequence of the activation at rest of a hyperpolarization-activated mixed-cation conductance and a low-threshold, depolarization-activated potassium conductance. The low input resistance causes rapid synaptic currents to generate rapid and small synaptic potentials. Summation of small synaptic potentials from many fibers is required to bring an octopus cell to threshold. Not only does the low input resistance make individual excitatory postsynaptic potentials brief so that they must be generated within 1 msec to sum but also the voltage-sensitive conductances of octopus cells prevent firing if the activation of auditory nerve inputs is not sufficiently synchronous and depolarization is not sufficiently rapid. In vivo in cats, octopus cells can fire rapidly and respond with exceptionally well-timed action potentials to periodic, broadband sounds such as clicks. Thus both the anatomical specializations and the biophysical specializations make octopus cells detectors of the coincident firing of their auditory nerve fiber inputs. PMID:11050208

  19. Diagnostic ability of Humphrey perimetry, Octopus perimetry, and optical coherence tomography for glaucomatous optic neuropathy.

    PubMed

    Monsalve, B; Ferreras, A; Calvo, P; Urcola, J A; Figus, M; Monsalve, J; Frezzotti, P

    2017-03-01

    PurposeTo evaluate and compare the diagnostic accuracy of the Humphrey Field Analyzer (HFA), Octopus perimetry, and Cirrus OCT for glaucomatous optic neuropathy.MethodsEighty-eight healthy individuals and 150 open-angle glaucoma patients were consecutive and prospectively selected. Eligibility criteria for the glaucoma group were intraocular pressure ≥21 mm Hg and glaucomatous optic nerve head morphology. All subjects underwent a reliable standard automated perimetry with the HFA and Octopus perimeter, and were imaged with the Cirrus OCT. Receiver-operating characteristic (ROC) curves were plotted for the threshold values and main indices of the HFA and Octopus, the peripapillary retinal nerve fiber layer thicknesses, and the optic nerve head parameters. Sensitivities at 85 and 95% fixed-specificities were also calculated. The best areas under the ROC curves (AUCs) were compared using the DeLong method.ResultsIn the glaucoma group, mean deviation (MD) was -5.42±4.6 dB for HFA and 3.90±3.6 dB for Octopus. The MD of the HFA (0.966; P<0.001), mean sensitivity of the Octopus (0.941; P<0.001), and average cup-to-disc (C/D) ratio measured by the Cirrus OCT (0.958; P<0.001) had the largest AUCs for each test studied. There were no significant differences among them. Sensitivities at 95% fixed-specificity were 82% for pattern standard deviation of the HFA, 81.3% for average C/D ratio of OCT, and 80% for the MD of the Octopus.ConclusionsHFA, Octopus, and Cirrus OCT demonstrated similar diagnostic accuracies for glaucomatous optic neuropathy. Visual field and OCT provide supplementary information and thus these tests are not interchangeable.

  20. Cryo-scanning electron microscopy investigation of the Octopus Vulgaris arm structures for the design of an octopus-like arm artefact.

    PubMed

    Minnocci, Antonio; Cianchetti, Matteo; Mazzolai, Barbara; Sebastiani, Luca; Laschi, Cecilia

    2015-12-01

    Octopus vulgaris is a cephalopod of the Octopodidae family. It has four pairs of arms and two rows of suckers which perform many functions, including bending and elongation. For this reason the octopus was chosen as model to develop a new generation of soft-body robots. In order to explain some of the fine structures of the octopus arm in relation to its specific ability, we examined the external and internal structures of O. vulgaris arms in a frozen-hydrated state using cryo-scanning electron microscopy. The arms showed skin with a very complex design that is useful to elongation, and a pore pattern distribution on their surface which is functional to cutaneous oxygen uptake. The analysis of freeze-fractured frozen-hydrated arm samples allowed us to describe the developmental differences in the relative proportion of the areas of axial nerve cord, intrinsic and extrinsic musculature, in relation to the growth of the arms and of the increase in functional capability. In the suckers, we analyzed the shedding mechanisms in the outer part of the infundibulum and described the outer and inner characteristics of the denticles, showing in detail their pore system, which is fundamental for their ability to explore the environment. These results are discussed by considering their possible application in the design of new octopus-like artefacts, which will be able to take advantage of some of these ultrastructure characteristics and achieve advanced bioinspired functionalities.

  1. 76 FR 66655 - Fisheries of the Exclusive Economic Zone Off Alaska; Pacific Cod and Octopus in the Bering Sea...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-27

    ... Economic Zone Off Alaska; Pacific Cod and Octopus in the Bering Sea and Aleutian Islands Management Area... necessary to limit incidental catch of octopus by vessels using pot gear to fish for Pacific cod the BSAI... Act requires that conservation and management measures prevent overfishing. The 2011...

  2. Occurrence of a tetrodotoxin-like compound in the eggs of the venomous blue-ringed octopus (Hapalochlaena maculosa).

    PubMed

    Sheumack, D D; Howden, M E; Spence, I

    1984-01-01

    A lethal toxin was isolated and partly purified from the eggs of the blue-ringed octopus, Hapalochlaena maculosa. Examination of the toxin by thin layer chromatography, isoelectric focusing and its effects upon the compound nerve action potentials of the toad sciatic nerve gave results that were indistinguishable from those displayed by authentic tetrodotoxin, the toxin present in the venom glands of the octopus.

  3. 76 FR 3044 - Fisheries of the Exclusive Economic Zone Off Alaska; Sculpins, Sharks, Squid, and Octopus in the...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-19

    ... Economic Zone Off Alaska; Sculpins, Sharks, Squid, and Octopus in the Gulf of Alaska AGENCY: National...: Temporary rule; closure. SUMMARY: NMFS is prohibiting directed fishing for sculpins, sharks, squid, and... allowable catch (TAC) of sculpins, sharks, squid, and octopus in the GOA. DATES: Effective 1200 hrs, Alaska...

  4. The packaging problem: bivalve prey selection and prey entry techniques of the octopus Enteroctopus dofleini.

    PubMed

    Anderson, Roland C; Mather, Jennifer A

    2007-08-01

    Many predators face a complex step of prey preparation before consumption. Octopuses faced with bivalve prey use several techniques to penetrate the shells to gain access to the meat inside. When given prey of mussels Mytilus trossulus, Manila clams Venerupis philippinarum, and littleneck clams Protothaca staminea, Enteroctopus dofleini solved the problem differently. They pulled apart V. philippinarum and M. trossulus, which had the thinnest shells and the least pulling resistance. P. staminea were eaten after the shells had been chipped or had been penetrated by drilling, presumably to inject a toxin. Likely because of these differences, octopuses consumed more V. philippinarum and M. trossulus than P. staminea when the mollusks were given to them either 1 species at a time or all together. However, when the shells were separated and the penetration problem removed, the octopuses predominantly chose P. staminea and nearly ignored M. trossulus. When V. philippinarum were wired shut, octopuses switched techniques. These results emphasize that octopuses can learn on the basis of nonvisual information and monitor their body position to carry out feeding actions.

  5. Soft robotic arm inspired by the octopus: I. From biological functions to artificial requirements.

    PubMed

    Margheri, L; Laschi, C; Mazzolai, B

    2012-06-01

    Octopuses are molluscs that belong to the group Cephalopoda. They lack joints and rigid links, and as a result, their arms possess virtually limitless freedom of movement. These flexible appendages exhibit peculiar biomechanical features such as stiffness control, compliance, and high flexibility and dexterity. Studying the capabilities of the octopus arm is a complex task that presents a challenge for both biologists and roboticists, the latter of whom draw inspiration from the octopus in designing novel technologies within soft robotics. With this idea in mind, in this study, we used new, purposively developed methods of analysing the octopus arm in vivo to create new biologically inspired design concepts. Our measurements showed that the octopus arm can elongate by 70% in tandem with a 23% diameter reduction and exhibits an average pulling force of 40 N. The arm also exhibited a 20% mean shortening at a rate of 17.1 mm s(-1) and a longitudinal stiffening rate as high as 2 N (mm s)(-1). Using histology and ultrasounds, we investigated the functional morphology of the internal tissues, including the sinusoidal arrangement of the nerve cord and the local insertion points of the longitudinal and transverse muscle fibres. The resulting information was used to create novel design principles and specifications that can in turn be used in developing a new soft robotic arm.

  6. An investigation of dendritic delay in octopus cells of the mammalian cochlear nucleus

    PubMed Central

    Spencer, Martin J.; Grayden, David B.; Bruce, Ian C.; Meffin, Hamish; Burkitt, Anthony N.

    2012-01-01

    Octopus cells, located in the mammalian auditory brainstem, receive their excitatory synaptic input exclusively from auditory nerve fibers (ANFs). They respond with accurately timed spikes but are broadly tuned for sound frequency. Since the representation of information in the auditory nerve is well understood, it is possible to pose a number of questions about the relationship between the intrinsic electrophysiology, dendritic morphology, synaptic connectivity, and the ultimate functional role of octopus cells in the brainstem. This study employed a multi-compartmental Hodgkin-Huxley model to determine whether dendritic delay in octopus cells improves synaptic input coincidence detection in octopus cells by compensating for the cochlear traveling wave delay. The propagation time of post-synaptic potentials from synapse to soma was investigated. We found that the total dendritic delay was approximately 0.275 ms. It was observed that low-threshold potassium channels in the dendrites reduce the amplitude dependence of the dendritic delay of post-synaptic potentials. As our hypothesis predicted, the model was most sensitive to acoustic onset events, such as the glottal pulses in speech when the synaptic inputs were arranged such that the model's dendritic delay compensated for the cochlear traveling wave delay across the ANFs. The range of sound frequency input from ANFs was also investigated. The results suggested that input to octopus cells is dominated by high frequency ANFs. PMID:23125831

  7. Organization of octopus arm movements: a model system for studying the control of flexible arms.

    PubMed

    Gutfreund, Y; Flash, T; Yarom, Y; Fiorito, G; Segev, I; Hochner, B

    1996-11-15

    Octopus arm movements provide an extreme example of controlled movements of a flexible arm with virtually unlimited degrees of freedom. This study aims to identify general principles in the organization of these movements. Video records of the movements of Octopus vulgaris performing the task of reaching toward a target were studied. The octopus extends its arm toward the target by a wave-like propagation of a bend that travels from the base of the arm toward the tip. Similar bend propagation is seen in other octopus arm movements, such as locomotion and searching. The kinematics (position and velocity) of the midpoint of the bend in three-dimensional space were extracted using the direct linear transformation algorithm. This showed that the bend tends to move within a single linear plane in a simple, slightly curved path connecting the center of the animal's body with the target location. Approximately 70% of the reaching movements demonstrated a stereotyped tangential velocity profile. An invariant profile was observed when movements were normalized for velocity and distance. Two arms, extended together in the same behavioral context, demonstrated identical velocity profiles. The stereotyped features of the movements were also observed in spontaneous arm extensions (not toward an external target). The simple and stereotypic appearance of the bend trajectory suggests that the position of the bend in space and time is the controlled variable. We propose that this strategy reduces the immense redundancy of the octopus arm movements and hence simplifies motor control.

  8. Total synthesis of a gene for octopus rhodopsin and its preliminary expression.

    PubMed

    Harada, Y; Sakamoto, T; Shinomura, T; Takamoto, K; Senda, T; Tsuda, M

    1991-10-01

    To carry out systematic structure-function studies of octopus rhodopsin, photoreceptor protein of octopus visual cells, by means of specific amino-acid replacements, we have totally synthesized a DNA duplex of 1,365 base pairs that encodes the entire octopus rhodopsin of 455 amino acids [Ovchinnikov et al. (1988) FEBS Lett. 232, 69-72] by introducing codons preferred in Escherichia coli. Total synthesis simplifies site-specific mutagenesis in all parts of the gene by replacement of short restriction fragments by their newly synthesized counterparts containing the required nucleotide alterations. Thirty unique restriction sites were introduced in the octopus rhodopsin gene, which was assembled on a plasmid in two steps. Five cartridge genes of 344, 296, 320, 212, and 317 base pairs capable of being expressed independently were first constructed by using 48 synthetic oligonucleotides ranging in size from 54 to 73 nucleotides. The entire gene was constructed by consecutive linkage of cartridge genes. These cartridge genes were designed to correspond to the transmembrane helical unit of octopus rhodopsin, resulting in easy construction of various chimeric rhodopsins. The nucleotide sequences were confirmed by sequencing the cartridges as well as the entire gene. These synthetic genes were cloned into an expression vector carrying the trp promoter of E. coli, and were preliminarily expressed in vitro and in vivo.

  9. Simple purification and functional reconstitution of octopus photoreceptor Gq, which couples rhodopsin to phospholipase C.

    PubMed

    Kikkawa, S; Tominaga, K; Nakagawa, M; Iwasa, T; Tsuda, M

    1996-12-10

    In invertebrate photoreceptors, illuminated rhodopsin activates multiple G proteins, which are assumed to initiate multiple phototransduction cascades. In this paper, we focused on one of the phototransduction cascades, which utilizes rhodopsin, a Gq-like G protein, and phospholipase C (PLC). A Gq-like G protein from octopus photoreceptors was successfully purified to apparent homogeneity as an active form by simple two-step chromatography. The purified G protein had an alpha beta gamma-trimeric structure consisting of 44-kDa alpha, 37-kDa beta, and 9-kDa gamma subunits. The 44-kDa alpha subunit was assigned to the Gq class by western blot with antiserum against mammalian Gq alpha and by partial amino acid sequencing of its proteolytic fragments. Light-dependent binding of GTP gamma S was observed when the purified octopus Gq was reconstituted with octopus rhodopsin that had been integrated into phospholipid vesicles. Octopus Gq activated PLC beta 1 purified from bovine brain dose-dependently in the presence of A1F4-. Finally, light- and GTP-dependent activation of PLC beta 1 was observed in a reconstitution system consisting of octopus rhodopsin, Gq, and bovine PLC beta 1.

  10. A purified agonist-activated G-protein coupled receptor: truncated octopus Acid Metarhodopsin.

    PubMed

    Ashida, Akemi; Matsumoto, Kumi; Ebrey, Thomas G; Tsuda, Motoyuki

    2004-03-01

    G-protein coupled receptors (GPCRs) mediate responses to many types of extracellular signals. So far, bovine rhodopsin, the inactive form of a GPCR, is the only member of the family whose three dimensional structure has been determined. It would be desirable to determine the structure of the active form of a GPCR. In this paper, we report the large scale preparation of a stable, homogenous species, truncated octopus rhodopsin (t-rhodopsin) in which proteolysis has removed the proline-rich C-terminal; this species retains the spectral properties and the ability for light-induced G-protein activation of unproteolyzed octopus rhodopsin. Moreover, starting from this species we can prepare a pure, active form of pigment, octopus t-Acid Metarhodopsin which has an all-trans-retinal as its agonist. Photoisomerization of t-Acid Metarhodopsin leads back to the inactive form, t-rhodopsin with the inverse agonist 11-cis-retinal. Octopus t-Acid Metarhodopsin can activate an endogenous octopus G-protein in the dark and this activity is reduced by irradiation with orange light which photoregenerates t-Acid Metarhodopsin back to the initial species, t-rhodopsin.

  11. Kinetic mechanism of octopus hepatopancreatic glutathione transferase in reverse micelles.

    PubMed Central

    Tang, S S; Chang, G G

    1996-01-01

    Octopus glutathione transferase (GST) was enzymically active in aerosol-OT [sodium bis-(2-ethylhexyl)sulphosuccinate]/iso-octane reverse micelles albeit with lowered catalytic constant (kcat). The enzyme reaction rate was found to be dependent on the [H2O]/[surfactant] ratio (omega(o)) of the system with maximum rate observed at omega(o) 13.88, which corresponded to vesicles with a core volume of 64 nm3. According to the physical examinations, a vesicle of this size is barely large enough to accommodate a monomeric enzyme subunit. Dissociation of the enzyme in reverse micelles was confirmed by cross-linking of the associated subunits with glutaraldehyde and separation of the monomers and dimers with electrophoresis in the presence of SDS. The kinetic properties of the enzyme were investigated by steady-state kinetic analysis. Both GSH and 1-chloro-2,4-dinitrobenzene (CDNB) showed substrate inhibition and the Michaelis constant for CDNB was increased by 36-fold to 11.05 mM in reverse micelles. Results on the initial-velocity and product-inhibition studies indicate that the octopus GST conforms to a steady-state sequential random Bi Bi mechanism. The results from a log kcat versus pH plot suggest that amino acid residues with pKa values of 6.56 0.07 and 8.81 0.17 should be deprotonated to give optimum catalytic function. In contrast, the amino acid residue with a pKa value of 9.69 0.16 in aqueous solution had to be protonated for the reaction to proceed. We propose that the pKa1 (6.56) is that for the enzyme-bound GSH, which has a pKa value lowered by 1.40-1.54 pH units compared with that of free GSH in reverse micelles. The most probable candidate for the observed pKa2 (8.81) is Tyr7 of GST. The pKa of Tyr7 is 0.88 pH unit lower than that in aqueous solution and is about 2 pH units below the normal tyrosine. This tyrosyl residue may act as a base catalyst facilitating the dissociation of enzyme-bound GSH. The possible interaction of GST with plasma membrane in vivo

  12. Kinetic mechanism of octopus hepatopancreatic glutathione transferase in reverse micelles.

    PubMed

    Tang, S S; Chang, G G

    1996-04-15

    Octopus glutathione transferase (GST) was enzymically active in aerosol-OT [sodium bis-(2-ethylhexyl)sulphosuccinate]/iso-octane reverse micelles albeit with lowered catalytic constant (kcat). The enzyme reaction rate was found to be dependent on the [H2O]/[surfactant] ratio (omega(o)) of the system with maximum rate observed at omega(o) 13.88, which corresponded to vesicles with a core volume of 64 nm3. According to the physical examinations, a vesicle of this size is barely large enough to accommodate a monomeric enzyme subunit. Dissociation of the enzyme in reverse micelles was confirmed by cross-linking of the associated subunits with glutaraldehyde and separation of the monomers and dimers with electrophoresis in the presence of SDS. The kinetic properties of the enzyme were investigated by steady-state kinetic analysis. Both GSH and 1-chloro-2,4-dinitrobenzene (CDNB) showed substrate inhibition and the Michaelis constant for CDNB was increased by 36-fold to 11.05 mM in reverse micelles. Results on the initial-velocity and product-inhibition studies indicate that the octopus GST conforms to a steady-state sequential random Bi Bi mechanism. The results from a log kcat versus pH plot suggest that amino acid residues with pKa values of 6.56 0.07 and 8.81 0.17 should be deprotonated to give optimum catalytic function. In contrast, the amino acid residue with a pKa value of 9.69 0.16 in aqueous solution had to be protonated for the reaction to proceed. We propose that the pKa1 (6.56) is that for the enzyme-bound GSH, which has a pKa value lowered by 1.40-1.54 pH units compared with that of free GSH in reverse micelles. The most probable candidate for the observed pKa2 (8.81) is Tyr7 of GST. The pKa of Tyr7 is 0.88 pH unit lower than that in aqueous solution and is about 2 pH units below the normal tyrosine. This tyrosyl residue may act as a base catalyst facilitating the dissociation of enzyme-bound GSH. The possible interaction of GST with plasma membrane in vivo

  13. OCTOPUS: improving topology prediction by two-track ANN-based preference scores and an extended topological grammar.

    PubMed

    Viklund, Håkan; Elofsson, Arne

    2008-08-01

    As alpha-helical transmembrane proteins constitute roughly 25% of a typical genome and are vital parts of many essential biological processes, structural knowledge of these proteins is necessary for increasing our understanding of such processes. Because structural knowledge of transmembrane proteins is difficult to attain experimentally, improved methods for prediction of structural features of these proteins are important. OCTOPUS, a new method for predicting transmembrane protein topology is presented and benchmarked using a dataset of 124 sequences with known structures. Using a novel combination of hidden Markov models and artificial neural networks, OCTOPUS predicts the correct topology for 94% of the sequences. In particular, OCTOPUS is the first topology predictor to fully integrate modeling of reentrant/membrane-dipping regions and transmembrane hairpins in the topological grammar. OCTOPUS is available as a web server at http://octopus.cbr.su.se.

  14. Characterization of Novel Cytoplasmic PARP in the Brain of Octopus vulgaris

    PubMed Central

    DE LISA, EMILIA; DE MAIO, ANNA; MOROZ, LEONID L.; MOCCIA, FRANCESCO; MENNELLA, MARIA ROSARIA FARAONE; DI COSMO, ANNA

    2014-01-01

    Recent investigation has focused on the participation of the poly (ADP-ribose) polymerase (PARP) reaction in the invertebrate central nervous system (CNS) during the process of long-term memory (LTM). In this paper, we characterize, localize, and assign a possible role to a cytoplasmic PARP in the brain of Octopus vulgaris. PARP activity was assayed in optic lobes, supraesophageal mass, and optic nerves. The highest levels of enzyme were found in the cytoplasmic fraction. Hyper-activation of the enzyme was detected in Octopus brain after visual discrimination training. Finally, cytoplasmic PARP was found to inhibit Octopus vulgaris actin polymerization. We propose that the cytoplasmic PARP plays a role in vivo to induce the cytoskeletonal reorganization that occurs during learning-induced neuronal plasticity. PMID:22815366

  15. Unveiling the morphology of the acetabulum in octopus suckers and its role in attachment

    PubMed Central

    Tramacere, Francesca; Pugno, Nicola M.; Kuba, Michael J.; Mazzolai, Barbara

    2015-01-01

    In recent years, the attachment mechanism of the octopus sucker has attracted the interest of scientists from different research areas, including biology, engineering, medicine and robotics. From a technological perspective, the main goal is to identify the underlying mechanisms involved in sucker attachment for use in the development of new generations of artificial devices and materials. Recently, the understanding of the morphology of the sucker has been significantly improved; however, the mechanisms that allow attachment remain largely unknown. In this work, we present new anatomical findings: specifically, a protuberance in the acetabular roof in five different octopus species; previously, this protuberance was identified by the authors in Octopus vulgaris. Moreover, we discuss the role of the protuberance and other anatomical structures in attachment with minimal energy consumption. PMID:25657834

  16. [Substrate-inhibitory analysis of monoamine oxidase from hepatopancreas of the octopus Bathypolypus arcticus].

    PubMed

    Basova, I N; Iagodina, O V

    2012-01-01

    Study of the substrate-inhibitory specificity of mitochondrial monoamine oxidase (MAO) of hepatopancreas of the octopus Bathypolypus arcticus revealed distinctive peculiarities of catalytic properties of this enzyme. The studied enzyme, on one hand, like the classic MAO of homoiothermal animals, is able to deaminate tyramine, serotonin, benzylamine, tryptamine, beta-phenylethylamine, while, on the other hand, deaminates histamine and does not deaminate putrescine--classic substrates of diamine oxidase (DAO). Results of the substrate-inhibitory analysis with use of chlorgiline and deprenyl are indirect proofs of the existence in the octopus hepatopancreas of one molecular MAO form. Semicarbazide and pyronine G turned out to be weak irreversible inhibitors, four derivatives of acridine--irreversible inhibitors of the intermediate effectiveness with respect to the octopus hepatopancreas MAO; specificity of action of inhibitors at deamination of different substrates was equal.

  17. Concentrations of biogenic amines in fish, squid and octopus and their changes during storage.

    PubMed

    Hu, Yue; Huang, Zhiyong; Li, Jian; Yang, Hong

    2012-12-15

    The concentrations of seven biogenic amines (BA) were simultaneously determined in 74 samples of fish, squid and octopus, by the method of HPLC coupled with pre-column derivatisation. The relationship between the formation of BA in aquatic products and the growth of microbial flora during storage was also investigated. Results showed that putrescine, cadaverine, histamine and tyramine were the dominant BA in the studied samples, but the concentrations of histamine and tyramine were mostly less than 50 and 100 mgkg(-1), respectively. Freezing can effectively prevent the formation of BA, but the levels of putrescine, cadaverine, histamine and tyramine significantly increased (p<0.05) during storage at 4 and 25°C. The growth of mesophilic or psychrophilic bacteria in blue scad and octopus strongly and positively correlated with the formation of amines (such as putrescine, cadaverine, histamine and tyramine) during storage, except for histamine in octopus.

  18. Bioactive Lipidic Extracts from Octopus (Paraoctopus limaculatus): Antimutagenicity and Antiproliferative Studies

    PubMed Central

    Moreno-Félix, Carolina; Wilson-Sánchez, Griselda; Cruz-Ramírez, Susana-Gabriela; Velázquez-Contreras, Carlos; Plascencia-Jatomea, Maribel; Acosta, Ana; Machi-Lara, Lorena; Aldana-Madrid, María-Lourdes; Ezquerra-Brauer, Josafat-Marina; Rocha-Alonzo, Fernando; Burgos-Hernández, Armando

    2013-01-01

    Fractions from an organic extract from fresh octopus (Paraoctopus limaculatus) were studied for biological activities such as antimutagenic and antiproliferative properties using Salmonella tester strains TA98 and TA100 with metabolic activation (S9) and a cancer cell line (B-cell lymphoma), respectively. A chloroform extract obtained from octopus tentacles was sequentially fractionated using thin layer chromatography (TLC), and each fraction was tested for antimutagenic and antiproliferative activities. Organic extract reduced the number of revertants caused by aflatoxin B1 showing a dose-response type of relationship. Sequential TLC fractionation of the active extracts produced several antimutagenic and/or antiproliferative fractions. Based on the results obtained, the isolated fractions obtained from octopus contain compounds with chemoprotective properties that reduce the mutagenicity of AFB1 and proliferation of cancer cell lines. PMID:23401709

  19. A novel photointermediate of octopus rhodopsin activates its G-protein.

    PubMed

    Nakagawa, M; Kikkawa, S; Tominaga, K; Tsugi, N; Tsuda, M

    1998-10-02

    The photointermediate of octopus rhodopsin responsible for G-protein activation was examined by a GTPgammaS-binding assay in a reconstituted system with purified rhodopsin and photoreceptor G-protein. When octopus rhodopsin alone was incubated in the dark after illumination, its ability to stimulate GTPgammaS-binding by the G-protein decreased in a time-dependent manner. We associate this decay with the decay of a novel photointermediate, transient acid metarhodopsin, which lies between mesorhodopsin and acid metarhodopsin. Spectroscopic evidence for its existence was suggested by its effects on the turbidity of the vesicles. These results suggest that the transient acid metarhodopsin, not the stable final photoproduct, acid metarhodopsin, activates a G-protein in octopus photoreceptors.

  20. Bioactive Lipidic Extracts from Octopus (Paraoctopus limaculatus): Antimutagenicity and Antiproliferative Studies.

    PubMed

    Moreno-Félix, Carolina; Wilson-Sánchez, Griselda; Cruz-Ramírez, Susana-Gabriela; Velázquez-Contreras, Carlos; Plascencia-Jatomea, Maribel; Acosta, Ana; Machi-Lara, Lorena; Aldana-Madrid, María-Lourdes; Ezquerra-Brauer, Josafat-Marina; Rocha-Alonzo, Fernando; Burgos-Hernández, Armando

    2013-01-01

    Fractions from an organic extract from fresh octopus (Paraoctopus limaculatus) were studied for biological activities such as antimutagenic and antiproliferative properties using Salmonella tester strains TA98 and TA100 with metabolic activation (S9) and a cancer cell line (B-cell lymphoma), respectively. A chloroform extract obtained from octopus tentacles was sequentially fractionated using thin layer chromatography (TLC), and each fraction was tested for antimutagenic and antiproliferative activities. Organic extract reduced the number of revertants caused by aflatoxin B(1) showing a dose-response type of relationship. Sequential TLC fractionation of the active extracts produced several antimutagenic and/or antiproliferative fractions. Based on the results obtained, the isolated fractions obtained from octopus contain compounds with chemoprotective properties that reduce the mutagenicity of AFB(1) and proliferation of cancer cell lines.

  1. Steroidogenesis in the brain of Sepia officinalis and Octopus vulgaris.

    PubMed

    Di Cristo, Carlo; Di Donato, Paola; Palumbo, Anna; d'Ischia, Marco; Paolucci, Marina; Di Cosmo, Anna

    2010-01-01

    The presence of vertebrate-like steroids, steroidogenic enzymes and steroid receptors has been reported exclusively in cephalopods gonads. The role played by these steroids has been also recently investigated. We here give evidence of steroidogenic activity in the brain of cephalopods. The activity of two key steroidogenic enzymes: 3beta-hydroxysteroid dehydrogenase (HSD) and 17beta-HSD is present in the lobes of the nervous system of both Sepia and Octopus. Such enzymes convert pregnenolone to progesterone and androstenedione to testosterone respectively. Binding experiments seem to assign a functional role to the androgens in the brain of cephalopods. According to the present results, the absence of any progesterone binding moiety supports the hypothesis that progesterone may be a metabolite product along the steroidogenic chain leading to androgens. The presence of steroidogenic enzymes in specific lobes of the central nervous system is discussed in terms of the possible role that steroids can play in the sexual differentiation of the brain and in influencing some coded behaviours of cephalopods, such as learning processes.

  2. The artisanal fishery for Octopus cyanea Gray in Tanzania.

    PubMed

    Guard, Martin; Mgaya, Yunus D

    2002-12-01

    Preliminary results for the artisanal fisheries of Octopus cyanea Gray (1849) in Tanzania are provided for the period April 2000 until June 2001. A total of 2546 individual catches and 15473 specimens were analyzed from 3 sites located at Tanga, Mafia Island, and Mtwara. Size range, average weight and catch per unit effort (CPUE) were all significantly lower at Tanga and Mtwara compared to Mafia indicating that the former sites may be overfished. Abundance of smaller individuals was higher at Tanga and Mtwara, but overall biomass was lower. Octopi at each site exhibited allometric growth as indicated by analyses of the length-weight relationships. Females become sexually mature at a minimum weight of 600 g while for males the minimum weight was 320 g. Higher numbers of mature individuals were found in June of both years and correlate with peaks in the gonosomatic index. Recruitment peaked a few months after brooding periods. Sex ratios indicate females may be more prone to capture during brooding periods. Reasons for differences between sites are discussed.

  3. Octopus-inspired drag cancelation by added mass pumping

    NASA Astrophysics Data System (ADS)

    Weymouth, Gabriel; Giorgio-Serchi, Francesco

    2016-11-01

    Recent work has shown that when an immersed body suddenly changes its size, such as a deflating octopus during rapid escape jetting, the body experiences large forces due to the variation of added-mass energy. We extend this line of research by investigating a spring-mass oscillator submerged in quiescent fluid subject to periodic changes in its volume. This system isolates the ability of the added-mass thrust to cancel the bluff body resistance (having no jet flow to confuse the analysis) and moves closer to studying how these effects would work in a sustained propulsion case by studying periodic shape-change instead of a "one-shot" escape maneuver. With a combination of analytical, numerical, and experimental results, we show that the recovery of added-mass kinetic energy can be used to completely cancel the drag of the fluid, driving the onset of sustained oscillations with amplitudes as large as four times the average body radius. Moreover, these results are fairly independent of the details of the shape-change kinematics as long as the Stokes number and shape-change number are large. In addition, the effective pumping frequency range based on parametric oscillator analysis is shown to predict large amplitude response region observed in the numerics and experiments.

  4. The subfrontal lobe and touch learning in the octopus.

    PubMed

    Wells, M J; Young, J Z

    1975-07-04

    Octopuses with the supraoesophageal lobes of the brain divided longitudinally can be taught to discriminate using the arms on either side. If there is no further lesion the two sides behave alike. Lesions limited to one side did not affect the performance of the contralateral, "control" side. Lesions made in the vertical (n=7) lobes led to a slight drop in the quality of performance in training to take a smooth sphere, in discrimination training (rough vs. smooth spheres) and in subsequent extinction and transfer tests. After removal of the median inferior frontal lobe (n = 10) there were somewhat greater effects in the same direction. Much larger effects followed interference with the subfrontal lobe (n = 20). Removal of parts from this always led to a marked loss of capacity for touch learning, broadly dependent on the amount of tissue removed. Removal of the whole of the subfrontal lobe (n = 6) produced animals that showed, at best, only very slight signs of learning. Such animals can adjust their overall level of response as a result of training but they seem incapable of adjusting response levels to two objects independently. These results are discussed in relation to the function of the subfrontal lobe as a memory store.

  5. Short-lasting memory in lower nervous centers in Octopus.

    PubMed

    Young, J Z

    1978-03-01

    Octopuses with the supraesophageal lobes split and the subesophageal centers isolated by cutting the cerebrobrachial connective on one or both sides were trained by food and shock rewards to discriminate between rough and smooth balls. Because there is a greater tendency to take the rough ball, training was done with the smooth ball positive for half the animals, and the rough ball positive for the others. In the animals with the cerebrobrachial connective cut only on one side, the subesophageal lobes showed no capacity to use the information gained by their opposite, intact, half-brains, which learned well. In animals with isolated subesophageal lobes, there was a decrease during each training session in the tendency to take both types of ball; however, this decrease did not persist from day to day. During each training session there were signs of discrimination between the balls by animals with isolated subesophageal lobes, but these also did not survive from day to day. In a series of training sessions spread over seven weeks, there was no change in results in animals with isolated subesophageal lobes when the smooth ball was positive. When the rough was positive the discrimination in its favor was slightly increased at later sessions.

  6. ELECTRON MICROSCOPY OF SYNAPTIC STRUCTURE OF OCTOPUS BRAIN

    PubMed Central

    Gray, E. G.; Young, J. Z.

    1964-01-01

    The well known type of synapse between a presynaptic process containing vesicles and a "clear" postsynaptic process can be commonly observed in the various lobes of the brain of Octopus. The presynaptic vesicles are aggregated near regions of the synaptic membranes which show specialisation and asymmetric "thickening" indicating functional polarisation, and here chemical transmission is presumed to take place. In addition, in the vertical lobe a very interesting serial arrangement of synaptic contacts occurs. Presynaptic bags, formed from varicosities of fibres from the superior frontal lobe, contact the trunks of amacrine cells in the manner just described. The trunks, however, although apparently postsynaptic are themselves packed with synaptic vesicles. The trunks, in turn, make "presynaptic" contacts with clear spinous processes of other neurons of yet undetermined origin. Typical polarised membrane specialisations occur at the contact regions. The trunk vesicles aggregated closest to the contact regions have a shell of particles round their walls. At present, there is no way of telling whether the membrane conductance to the various ions is differently affected at either of the transmission sites, and, if an inhibitory mechanism is involved, whether it is of the presynaptic or postsynaptic variety. PMID:14154498

  7. Transcriptome analysis of the Octopus vulgaris central nervous system.

    PubMed

    Zhang, Xiang; Mao, Yong; Huang, Zixia; Qu, Meng; Chen, Jun; Ding, Shaoxiong; Hong, Jingni; Sun, Tiantian

    2012-01-01

    Cephalopoda are a class of Mollusca species found in all the world's oceans. They are an important model organism in neurobiology. Unfortunately, the lack of neuronal molecular sequences, such as ESTs, transcriptomic or genomic information, has limited the development of molecular neurobiology research in this unique model organism. With high-throughput Illumina Solexa sequencing technology, we have generated 59,859 high quality sequences from 12,918,391 paired-end reads. Using BLASTx/BLASTn, 12,227 contigs have blast hits in the Swissprot, NR protein database and NT nucleotide database with E-value cutoff 1e(-5). The comparison between the Octopus vulgaris central nervous system (CNS) library and the Aplysia californica/Lymnaea stagnalis CNS ESTs library yielded 5.93%/13.45% of O. vulgaris sequences with significant matches (1e(-5)) using BLASTn/tBLASTx. Meanwhile the hit percentage of the recently published Schistocerca gregaria, Tilapia or Hirudo medicinalis CNS library to the O. vulgaris CNS library is 21.03%-46.19%. We constructed the Phylogenetic tree using two genes related to CNS function, Synaptotagmin-7 and Synaptophysin. Lastly, we demonstrated that O. vulgaris may have a vertebrate-like Blood-Brain Barrier based on bioinformatic analysis. This study provides a mass of molecular information that will contribute to further molecular biology research on O. vulgaris. In our presentation of the first CNS transcriptome analysis of O. vulgaris, we hope to accelerate the study of functional molecular neurobiology and comparative evolutionary biology.

  8. ELECTRON MICROSCOPY OF SYNAPTIC STRUCTURE OF OCTOPUS BRAIN.

    PubMed

    GRAY, E G; YOUNG, J Z

    1964-04-01

    The well known type of synapse between a presynaptic process containing vesicles and a "clear" postsynaptic process can be commonly observed in the various lobes of the brain of Octopus. The presynaptic vesicles are aggregated near regions of the synaptic membranes which show specialisation and asymmetric "thickening" indicating functional polarisation, and here chemical transmission is presumed to take place. In addition, in the vertical lobe a very interesting serial arrangement of synaptic contacts occurs. Presynaptic bags, formed from varicosities of fibres from the superior frontal lobe, contact the trunks of amacrine cells in the manner just described. The trunks, however, although apparently postsynaptic are themselves packed with synaptic vesicles. The trunks, in turn, make "presynaptic" contacts with clear spinous processes of other neurons of yet undetermined origin. Typical polarised membrane specialisations occur at the contact regions. The trunk vesicles aggregated closest to the contact regions have a shell of particles round their walls. At present, there is no way of telling whether the membrane conductance to the various ions is differently affected at either of the transmission sites, and, if an inhibitory mechanism is involved, whether it is of the presynaptic or postsynaptic variety.

  9. Connections of the octopus optic lobe: an HRP study.

    PubMed

    Saidel, W M

    1982-04-20

    The major visual centers of the octopus central nervous system are the paired optic lobes. Bidirectional transport of horseradish peroxidase (HRP) was used to determine connections of the optic lobe. Cells afferent to the optic lobe were identified by retrograde HRP transport in the following lobes of the central ganglia: anterior basal, median basal, dorsal basal, interbasal, subvertical, precommissural, brachial, and magnocellular. Labeled cells were also observed within the contralateral optic lobe, various optic tract lobes bilaterally, and in photoreceptors of the ipsilateral retina. Additionally, individual fibers, in part originating from cells in the posterior subvertical lobe, were labeled within the central neuropil core of various vertical lobules. Differences in results between superficial and deep optic lobe medulla injections indicate that some afferent projections from central sources may terminate on cell populations at specific depths within the lobe. Efferent optic lobe fibers into the superior frontal and lateral basal lobes were labeled by anterograde transport. Other possible optic lobe efferent projections terminated in supraesophageal lobes and the magnocellular lobe. The many inputs to the optic lobe from higher motor and associative centers in the central ganglia emphasize that the medulla region of the optic lobe is an exceptionally complex integrative area.

  10. The complete mitochondrial genome of Octopus bimaculatus Verrill, 1883 from the Gulf of California.

    PubMed

    Domínguez-Contreras, José Francisco; Munguia-Vega, Adrian; Ceballos-Vázquez, Bertha Patricia; García-Rodriguez, Francisco Javier; Arellano-Martinez, Marcial

    2016-11-01

    The complete mitochondrial genome of Octopus bimaculatus is 16 085 bp in length and includes 13 protein-codes genes, 2 ribosomal RNA genes, 22 transfers RNA genes, and a control region. The composition of genome is A (40.9%), T (34.7%), C (16.9%), and G (7.5%). The control region of O. bimaculatus contains a VNTR locus not present in the genomes from other octopus species. A phylogenetic analysis shows a closer relationship between the mitogenomes from O. bimaculatus and O. vulgaris.

  11. Threonine is the best substrate for D-lactate formation in octopus tentacle.

    PubMed

    Akagi, S; Ohmori, S

    2004-03-01

    Carbon sources for D-lactate and enzyme activities related to D-lactate formation were investigated using cell-free homogenates of Octopus vulgaris tentacle tissue. The results are as follows: a) The best precursor for D-lactate formation was threonine and second best precursors were glycine and fructose-1,6-bisphosphate. Threonine and glycine served as precursors only in presence of glutathione. b) Both amino acids were precursors for methylglyoxal from which D-lactate was synthesized. Alanine, cysteine and serine were not precursors. We present a metabolic map for D-lactate formation in octopus in order to explain these experimental results.

  12. Proteomic characterization of the hemolymph of Octopus vulgaris infected by the protozoan parasite Aggregata octopiana.

    PubMed

    Castellanos-Martínez, Sheila; Diz, Angel P; Álvarez-Chaver, Paula; Gestal, Camino

    2014-06-13

    The immune system of cephalopods is poorly known to date. The lack of genomic information makes difficult to understand vital processes like immune defense mechanisms and their interaction with pathogens at molecular level. The common octopus Octopus vulgaris has a high economic relevance and potential for aquaculture. However, disease outbreaks provoke serious reductions in production with potentially severe economic losses. In this study, a proteomic approach is used to analyze the immune response of O. vulgaris against the coccidia Aggregata octopiana, a gastrointestinal parasite which impairs the cephalopod nutritional status. The hemocytes and plasma proteomes were compared by 2-DE between sick and healthy octopus. The identities of 12 differentially expressed spots and other 27 spots without significant alteration from hemocytes, and 5 spots from plasma, were determined by mass spectrometry analysis aided by a six reading-frame translation of an octopus hemocyte RNA-seq database and also public databases. Principal component analysis pointed to 7 proteins from hemocytes as the major contributors to the overall difference between levels of infection and so could be considered as potential biomarkers. Particularly, filamin, fascin and peroxiredoxin are highlighted because of their implication in octopus immune defense activity. From the octopus plasma, hemocyanin was identified. This work represents a first step forward in order to characterize the protein profile of O. vulgaris hemolymph, providing important information for subsequent studies of the octopus immune system at molecular level and also to the understanding of the basis of octopus tolerance-resistance to A. octopiana. The immune system of cephalopods is poorly known to date. The lack of genomic information makes difficult to understand vital processes like immune defense mechanisms and their interaction with pathogens at molecular level. The study herein presented is focused to the comprehension of

  13. Histochemical evidence for catecholamines as neurotransmitters in the statocyst of Octopus vulgaris.

    PubMed

    Budelmann, B U; Bonn, U

    1982-01-01

    Formaldehyde-induced fluorescence (Falck-Hillarp technique) provided histochemical evidence for the presence of catecholamines in the sensory epithelia (macula and crista) of the Octopus statocyst. A specific bright green fluorescence occurred in the neuronal plexus beneath the receptor cell layers of the epithelia and in the appropriate nerves. The histochemical findings are discussed with reference to the well-known neuronal and synaptic organization of the epithelia and to relevant results in cephalopods as well as in other molluscs. All data support the hypothesis that in the receptor systems of the Octopus statocyst catecholamines (probably dopamine and/or noradrenaline) act as neurotransmitters in the efferent fibre system.

  14. Eye-independent, light-activated chromatophore expansion (LACE) and expression of phototransduction genes in the skin of Octopus bimaculoides

    PubMed Central

    Ramirez, M. Desmond; Oakley, Todd H.

    2015-01-01

    ABSTRACT Cephalopods are renowned for changing the color and pattern of their skin for both camouflage and communication. Yet, we do not fully understand how cephalopods control the pigmented chromatophore organs in their skin and change their body pattern. Although these changes primarily rely on eyesight, we found that light causes chromatophores to expand in excised pieces of Octopus bimaculoides skin. We call this behavior light-activated chromatophore expansion (or LACE). To uncover how octopus skin senses light, we used antibodies against r-opsin phototransduction proteins to identify sensory neurons that express r-opsin in the skin. We hypothesized that octopus LACE relies on the same r-opsin phototransduction cascade found in octopus eyes. By creating an action spectrum for the latency to LACE, we found that LACE occurred most quickly in response to blue light. We fit our action spectrum data to a standard opsin curve template and estimated the λmax of LACE to be 480 nm. Consistent with our hypothesis, the maximum sensitivity of the light sensors underlying LACE closely matches the known spectral sensitivity of opsin from octopus eyes. LACE in isolated preparations suggests that octopus skin is intrinsically light sensitive and that this dispersed light sense might contribute to their unique and novel patterning abilities. Finally, our data suggest that a common molecular mechanism for light detection in eyes may have been co-opted for light sensing in octopus skin and then used for LACE. PMID:25994633

  15. Eye-independent, light-activated chromatophore expansion (LACE) and expression of phototransduction genes in the skin of Octopus bimaculoides.

    PubMed

    Ramirez, M Desmond; Oakley, Todd H

    2015-05-15

    Cephalopods are renowned for changing the color and pattern of their skin for both camouflage and communication. Yet, we do not fully understand how cephalopods control the pigmented chromatophore organs in their skin and change their body pattern. Although these changes primarily rely on eyesight, we found that light causes chromatophores to expand in excised pieces of Octopus bimaculoides skin. We call this behavior light-activated chromatophore expansion (or LACE). To uncover how octopus skin senses light, we used antibodies against r-opsin phototransduction proteins to identify sensory neurons that express r-opsin in the skin. We hypothesized that octopus LACE relies on the same r-opsin phototransduction cascade found in octopus eyes. By creating an action spectrum for the latency to LACE, we found that LACE occurred most quickly in response to blue light. We fit our action spectrum data to a standard opsin curve template and estimated the λmax of LACE to be 480 nm. Consistent with our hypothesis, the maximum sensitivity of the light sensors underlying LACE closely matches the known spectral sensitivity of opsin from octopus eyes. LACE in isolated preparations suggests that octopus skin is intrinsically light sensitive and that this dispersed light sense might contribute to their unique and novel patterning abilities. Finally, our data suggest that a common molecular mechanism for light detection in eyes may have been co-opted for light sensing in octopus skin and then used for LACE.

  16. Octopus-inspired multi-arm robotic swimming.

    PubMed

    Sfakiotakis, M; Kazakidi, A; Tsakiris, D P

    2015-05-13

    The outstanding locomotor and manipulation characteristics of the octopus have recently inspired the development, by our group, of multi-functional robotic swimmers, featuring both manipulation and locomotion capabilities, which could be of significant engineering interest in underwater applications. During its little-studied arm-swimming behavior, as opposed to the better known jetting via the siphon, the animal appears to generate considerable propulsive thrust and rapid acceleration, predominantly employing movements of its arms. In this work, we capture the fundamental characteristics of the corresponding complex pattern of arm motion by a sculling profile, involving a fast power stroke and a slow recovery stroke. We investigate the propulsive capabilities of a multi-arm robotic system under various swimming gaits, namely patterns of arm coordination, which achieve the generation of forward, as well as backward, propulsion and turning. A lumped-element model of the robotic swimmer, which considers arm compliance and the interaction with the aquatic environment, was used to study the characteristics of these gaits, the effect of various kinematic parameters on propulsion, and the generation of complex trajectories. This investigation focuses on relatively high-stiffness arms. Experiments employing a compliant-body robotic prototype swimmer with eight compliant arms, all made of polyurethane, inside a water tank, successfully demonstrated this novel mode of underwater propulsion. Speeds of up to 0.26 body lengths per second (approximately 100 mm s(-1)), and propulsive forces of up to 3.5 N were achieved, with a non-dimensional cost of transport of 1.42 with all eight arms and of 0.9 with only two active arms. The experiments confirmed the computational results and verified the multi-arm maneuverability and simultaneous object grasping capability of such systems.

  17. Venom on ice: first insights into Antarctic octopus venoms.

    PubMed

    Undheim, E A B; Georgieva, D N; Thoen, H H; Norman, J A; Mork, J; Betzel, C; Fry, B G

    2010-11-01

    The venom of Antarctic octopus remains completely unstudied. Here, a preliminary investigation was conducted into the properties of posterior salivary gland (PSG) extracts from four Antarctica eledonine (Incirrata; Octopodidae) species (Adelieledone polymorpha, Megaleledone setebos, Pareledone aequipapillae, and Pareledone turqueti) collected from the coast off George V's Land, Antarctica. Specimens were assayed for alkaline phosphatase (ALP), acetylcholinesterase (AChE), proteolytic, phospholipase A(2) (PLA(2)), and haemolytic activities. For comparison, stomach tissue from Cirroctopus sp. (Cirrata; Cirroctopodidae) was also assayed for ALP, AChE, proteolytic and haemolytic activities. Dietary and morphological data were collected from the literature to explore the ecological importance of venom, taking an adaptive evolutionary approach. Of the incirrate species, three showed activities in all assays, while P. turqueti did not exhibit any haemolytic activity. There was evidence for cold-adaptation of ALP in all incirrates, while proteolytic activity in all except P. turqueti. Cirroctopus sp. stomach tissue extract showed ALP, AChE and some proteolytic activity. It was concluded that the AChE activity seen in the PSG extracts was possibly due to a release of household proteins, and not one of the secreted salivary toxins. Although venom undoubtedly plays an important part in prey capture and processing by Antarctica eledonines, no obvious adaptations to differences in diet or morphology were apparent from the enzymatic and haemolytic assays. However, several morphological features including enlarged PSG, small buccal mass, and small beak suggest such adaptations are present. Future studies should be conducted on several levels: Venomic, providing more detailed information on the venom compositions as well as the venom components themselves; ecological, for example application of serological or genetic methods in identifying stomach contents; and behavioural

  18. Photoenergetics of octopus rhodopsin. Convergent evolution of biological photon counters?

    PubMed

    Cooper, A; Dixon, S F; Tsuda, M

    1986-01-01

    The enthalpy changes associated with each of the major steps in the photoconversion of octopus rhodopsin have been measured by direct photocalorimetry. Formation of the primary photoproduct (bathorhodopsin) involves energy uptake of about 130 kJ/mol, corresponding to storage of over 50% of the exciting photon energy, and is comparable to the energy storage previously observed in bovine rhodopsin. Subsequent intermediates involve the step-wise dissipation of this energy to give the physiological end-product (acid metarhodopsin) at a level only slightly above the parent rhodopsin. No significant differences in energetics are observed between rhodopsin in microvilli membrane suspensions or detergent dispersions. Use of different buffer systems in the calorimetric experiments shows that conversion of rhodopsin to acid metarhodopsin involves no light-induced protonation change, whereas alkali metarhodopsin photoproduction occurs with the release of one proton per molecule and an additional enthalpy increase of about 50 kJ/mol. Van't Hoff analysis of the effect of temperature on the reversible metarhodopsin equilibrium gives an enthalpy for the acid----alkali transition consistent with this calorimetric result, and the proton release is confirmed by direct observation of light-induced pH changes. Acid-base titration of metarhodopsin yields an apparent pK of 9.5 for this transition, though the pH profile deviates slightly from ideal titration behaviour. We suggest that a high energy primary photoproduct is an obligatory feature of efficient biological photo-detectors, as opposed to photon energy transducers, and that the similarity at this stage between cephalopod and vertebrate rhodopsins represents either convergent evolution at the molecular level or strong conservation of a crucial functional characteristic.

  19. Transcriptome Analysis of the Octopus vulgaris Central Nervous System

    PubMed Central

    Zhang, Xiang; Mao, Yong; Huang, Zixia; Qu, Meng; Chen, Jun; Ding, Shaoxiong; Hong, Jingni; Sun, Tiantian

    2012-01-01

    Background Cephalopoda are a class of Mollusca species found in all the world's oceans. They are an important model organism in neurobiology. Unfortunately, the lack of neuronal molecular sequences, such as ESTs, transcriptomic or genomic information, has limited the development of molecular neurobiology research in this unique model organism. Results With high-throughput Illumina Solexa sequencing technology, we have generated 59,859 high quality sequences from 12,918,391 paired-end reads. Using BLASTx/BLASTn, 12,227 contigs have blast hits in the Swissprot, NR protein database and NT nucleotide database with E-value cutoff 1e−5. The comparison between the Octopus vulgaris central nervous system (CNS) library and the Aplysia californica/Lymnaea stagnalis CNS ESTs library yielded 5.93%/13.45% of O. vulgaris sequences with significant matches (1e−5) using BLASTn/tBLASTx. Meanwhile the hit percentage of the recently published Schistocerca gregaria, Tilapia or Hirudo medicinalis CNS library to the O. vulgaris CNS library is 21.03%–46.19%. We constructed the Phylogenetic tree using two genes related to CNS function, Synaptotagmin-7 and Synaptophysin. Lastly, we demonstrated that O. vulgaris may have a vertebrate-like Blood-Brain Barrier based on bioinformatic analysis. Conclusion This study provides a mass of molecular information that will contribute to further molecular biology research on O. vulgaris. In our presentation of the first CNS transcriptome analysis of O. vulgaris, we hope to accelerate the study of functional molecular neurobiology and comparative evolutionary biology. PMID:22768275

  20. Identification of triosephosphate isomerase as a novel allergen in Octopus fangsiao.

    PubMed

    Yang, Yang; Chen, Zhong-Wei; Hurlburt, Barry K; Li, Gui-Ling; Zhang, Yong-Xia; Fei, Dan-Xia; Shen, Hai-Wang; Cao, Min-Jie; Liu, Guang-Ming

    2017-02-13

    Octopus is an important mollusk in human dietary for its nutritional value, however it also causes allergic reactions in humans. Major allergens from octopus have been identified, while the knowledge of novel allergens remains poor. In the present study, a novel allergen with molecular weight of 28kDa protein was purified from octopus (Octopus fangsiao) and identified as triosephosphate isomerase (TIM) by mass spectrometry. TIM aggregated beyond 45°C, and its IgE-binding activity was affected under extreme pH conditions due to the altered secondary structure. In simulated gastric fluid digestion, TIM can be degraded into small fragments, while retaining over 80% of the IgE-binding activity. The full-length cDNA of O. fangsiao TIM (1140bp) was cloned, which encodes 247 amino acid residues, and the entire recombinant TIM was successfully expressed in Escherichia coli BL21, which showed similar immunoreactivity to the native TIM. Different intensity of cross-reactivity among TIM from related species revealed the complexity of its epitopes. Eight linear epitopes of TIM were predicted following bioinformatic analysis. Furthermore, a conformational epitope (A71G74S69D75T73F72V67) was confirmed by the phage display technology. The results revealed the physicochemical and immunological characteristics of TIM, which is significant in the development of hyposensitivity food and allergy diagnosis.

  1. Survival after severe envenomation by the blue-ringed octopus (Hapalochlaena maculosa).

    PubMed

    Walker, D G

    I report two cases of life-endangering respiratory failure after envenomation by a blue-ringed octopus (Hapalochlaena maculosa). Early and efficient support of respiratory function is vital in such cases. Cardiac asystole occurred in one patient. Both patients recovered completely after the vigorous application of routine resuscitation techniques.

  2. Egg brooding by deep-sea octopuses in the North Pacific Ocean.

    PubMed

    Voight, J R; Grehan, A J

    2000-02-01

    Videotapes made from the submersible Alvin on Baby Bare, a 2600-m-deep North Pacific basalt outcrop, and at two other deep-sea localities document that octopuses of the genera Graneledone and Benthoctopus attach their eggs to hard substrate and apparently brood them through development. The behavior of brooding females was generally similar to that of shallow-water octopuses, but the genera showed apparent differences. In addition to the high density of brooding females observed at Baby Bare, which may relate to the increased availability of exposed hard substrates for egg attachment and of prey, females are suggested to increasingly associate with hard substrates as they mature. The biology of Baby Bare may seem unduly unique because the outcrop is isolated on a sedimented plain and is among the few exposures of hard substrate other than hydrothermal vents that have been explored by submersible. On the sediment-covered ocean floor, the availability of hard substrate may strongly affect the distribution of brooding octopuses. The size and shape of boreholes in 19 of over 400 thyasirid clam shells collected from Baby Bare support the hypothesis that octopuses had preyed upon the clams.

  3. Olfactory organ of Octopus vulgaris: morphology, plasticity, turnover and sensory characterization

    PubMed Central

    Polese, Gianluca; Bertapelle, Carla

    2016-01-01

    ABSTRACT The cephalopod olfactory organ was described for the first time in 1844 by von Kölliker, who was attracted to the pair of small pits of ciliated cells on each side of the head, below the eyes close to the mantle edge, in both octopuses and squids. Several functional studies have been conducted on decapods but very little is known about octopods. The morphology of the octopus olfactory system has been studied, but only to a limited extent on post-hatching specimens, and the only paper on adult octopus gives a minimal description of the olfactory organ. Here, we describe the detailed morphology of young male and female Octopus vulgaris olfactory epithelium, and using a combination of classical morphology and 3D reconstruction techniques, we propose a new classification for O. vulgaris olfactory sensory neurons. Furthermore, using specific markers such as olfactory marker protein (OMP) and proliferating cell nuclear antigen (PCNA) we have been able to identify and differentially localize both mature olfactory sensory neurons and olfactory sensory neurons involved in epithelium turnover. Taken together, our data suggest that the O. vulgaris olfactory organ is extremely plastic, capable of changing its shape and also proliferating its cells in older specimens. PMID:27069253

  4. Octopus-Inspired Smart Adhesive Pads for Transfer Printing of Semiconducting Nanomembranes.

    PubMed

    Lee, Hochan; Um, Doo-Seung; Lee, Youngsu; Lim, Seongdong; Kim, Hyung-Jun; Ko, Hyunhyub

    2016-09-01

    By mimicking muscle actuation to control cavity-pressure-induced adhesion of octopus suckers, smart adhesive pads are developed in which the thermoresponsive actuation of a hydrogel layer on elastomeric microcavity pads enables excellent switchable adhesion in response to a thermal stimulus (maximum adhesive strength: 94 kPa, adhesion switching ratio: ≈293 for temperature change between 22 and 61 °C).

  5. OCTOPUS--A Church-Based Sex Education Program for Teens and Parents.

    ERIC Educational Resources Information Center

    Jacknik, Michele; And Others

    1984-01-01

    Describes OCTOPUS (Open Communication Regarding Teenagers or Parents Understanding of Sexuality), which was established as a forum for family discussion within a church setting. The program was designed to enhance communication skills, convey information, and help teenagers acquire appropriate morals and values. Feedback from four churches…

  6. Learning and memory in Octopus vulgaris: a case of biological plasticity.

    PubMed

    Zarrella, Ilaria; Ponte, Giovanna; Baldascino, Elena; Fiorito, Graziano

    2015-12-01

    Here we concisely summarize major aspects of the learning capabilities of the cephalopod mollusc Octopus vulgaris, a solitary living marine invertebrate. We aim to provide a backdrop against which neurobiology of these animals can be further interpreted and thus soliciting further interest for one of the most advanced members of invertebrate animals.

  7. Rearing and growth of the Octopus Robsonella fontaniana (Cephalopoda: Octopodidae) from planktonic hatchlings to benthic juveniles.

    PubMed

    Uriarte, Iker; Hernández, Jorge; Dörner, Jessica; Paschke, Kurt; Farías, Ana; Crovetto, Enzo; Rosas, Carlos

    2010-04-01

    Globally, octopus larviculture is one of the challenges faced in the attempt to diversify aquaculture and achieve cephalopod farming. Currently, only juveniles of Octopus vulgaris, Octopus joubini, and Enteroctopus dofleini have been obtained at an experimental level. This is the first study to look at the characteristics of planktonic and benthic Robsonella fontaniana juveniles in an effort to analyze the morphometric changes occurring during their planktonic and benthic phases and to explore the feasibility of obtaining settlement under controlled conditions. The morphometric measurements varied exponentially over time and did not show different tendencies before and after settlement. Mantle growth in relation to total length fit a logarithmic regression, whereas arm length and eye diameter increased linearly with respect to total length throughout the entire paralarval and juvenile periods. This suggests that the size of the mantle decreases with age in proportion to the total octopus length, whereas the organs more directly involved in catching prey tend to increase in direct proportion to the total length. The present study shows that R. fontaniana can be reared from hatching through the final paralarval stage on a diet of Lithodes santolla (king crab) zoeae; after settlement, the juveniles can be reared on a diet of crab such as Petrolisthes.

  8. Comparative molecular analysis of evolutionarily distant glyceraldehyde-3-phosphate dehydrogenase from Sardina pilchardus and Octopus vulgaris.

    PubMed

    Baibai, Tarik; Oukhattar, Laila; Mountassif, Driss; Assobhei, Omar; Serrano, Aurelio; Soukri, Abdelaziz

    2010-12-01

    The NAD(+)-dependent cytosolic glyceraldehyde-3-phosphate dehydrogenase (GAPDH, EC 1.2.1.12), which is recognized as a key to central carbon metabolism in glycolysis and gluconeogenesis and as an important allozymic polymorphic biomarker, was purified from muscles of two marine species: the skeletal muscle of Sardina pilchardus Walbaum (Teleost, Clupeida) and the incompressible arm muscle of Octopus vulgaris (Mollusca, Cephalopoda). Comparative biochemical studies have revealed that they differ in their subunit molecular masses and in pI values. Partial cDNA sequences corresponding to an internal region of the GapC genes from Sardina and Octopus were obtained by polymerase chain reaction using degenerate primers designed from highly conserved protein motifs. Alignments of the deduced amino acid sequences were used to establish the 3D structures of the active site of two enzymes as well as the phylogenetic relationships of the sardine and octopus enzymes. These two enzymes are the first two GAPDHs characterized so far from teleost fish and cephalopod, respectively. Interestingly, phylogenetic analyses indicated that the sardina GAPDH is in a cluster with the archetypical enzymes from other vertebrates, while the octopus GAPDH comes together with other molluscan sequences in a distant basal assembly closer to bacterial and fungal orthologs, thus suggesting their different evolutionary scenarios.

  9. Maculotoxin: a neurotoxin from the venom glands of the octopus Hapalochlaena maculosa identified as tetrodotoxin.

    PubMed

    Sheumack, D D; Howden, M E; Spence, I; Quinn, R J

    1978-01-13

    Maculotoxin, a potent neurotoxin isolated from the posterior salivary glands of the blue-ringed octopus. Hapalochlaena maculosa, has now been identified as tetrodotoxin. This is the first reported case in which tetrodotoxin has been found to occur in a venom.

  10. Distribution of tetrodotoxin in the body of the blue-ringed octopus (Hapalochlaena maculosa).

    PubMed

    Yotsu-Yamashita, Mari; Mebs, Dietrich; Flachsenberger, Wolfgang

    2007-03-01

    Tetrodotoxin (TTX) was quantitatively assayed in six specimens of semi-adult blue-ringed octopus, Hapalochlaena maculosa, by a post-column fluorescent-HPLC system. TTX was found to be present in all body parts, e.g. in high concentrations in the arms followed by the abdomen and cephalothorax. The toxin is not associated exclusively with the posterior salivary gland.

  11. Pseudomonas oryzihabitans cutaneous ulceration from Octopus vulgaris bite: a case report and review of the literature.

    PubMed

    Aigner, Birgit Angela; Ollert, Markus; Seifert, Florian; Ring, Johannes; Plötz, Sabine Gisela

    2011-08-01

    Octopus vulgaris is a common marine animal that can be found in nearly all tropical and semitropical waters around the world. It is a peaceful sea dweller with a parrotlike beak, and its primary defense is to hide through camouflaging adjustments. Bites from animals of the class Cephalopoda are very rare. We describe a boy who was bitten on his forearm by an Octopus vulgaris. A 9 -year-old boy was bitten by an Octopus vulgaris while snorkeling. There was no strong bleeding or systemic symptoms; however, 2 days later, a cherry-sized, black, ulcerous lesion developed, surrounded by a red circle that did not heal over months and therefore had to be excised. Histologic examination showed ulceration with extensive necrosis of the dermis and the epidermis. A microbial smear revealed Pseudomonas (formerly known as Flavimonas) oryzihabitans. After excision, the wound healed within 2 weeks, without any complications or signs of infection. To the best of our knowledge, this case represents the first report of an Octopus vulgaris bite resulting in an ulcerative lesion with slow wound healing owing to P oryzihabitans infection. We recommend greater vigilance regarding bacterial contamination when treating skin lesions caused by marine animals.

  12. Resonance Raman studies of the HOOP modes in octopus bathorhodopsin with deuterium-labeled retinal chromophores

    SciTech Connect

    Deng, H.; Manor, D.; Weng, G.; Rath, P.; Callender, R.H. ); Koutalos, Y.; Ebrey, T. ); Gebhard, R.; Lugtenburg, J. ); Tsuda, M. )

    1991-05-07

    Resonance Raman spectra of the hydrogen out-of-plane (HOOP) vibrational modes in the retinal chromophore of octopus bathorhodopsin with deuterium label(s) along the polyene chain have been obtained. In clear contrast with bovine bathorhodopsin's HOOP modes, there are only two major HOOP bands at 887 and 940 cm{sup {minus}1} for octopus bathorhodopsin. On the basis of their isotopic shifts upon deuterium labeling, the authors have assigned the band at 887 cm{sup {minus}1} to C{sub 10}H and C{sub 14}H HOOP modes, and the band at 940 cm{sup {minus}1} to C{sub 11}H{double bond}C{sub 12}H A{sub u}-like HOOP mode. They found also that the C{sub 10}H and C{sub 14}H HOOP wags are also similar to those in the model-compound studies. However, they have found that the interaction between the C{sub 7}H and C{sub 8}H HOOP internal coordinates of the chromophore in octopus bathorhodopsin is different from that of the chromophore in solution. The twisted nature of the chromophore, semiquantitatively discussed here, likely affects the {lambda}{sub max} of the chromophore and its enthalpy. The nature of the HOOP modes of octopus bathorhodopsin differs substantially from those found in bovine bathorhodopsin.

  13. Octopus conditioning: a multi-armed approach to the LTP--learning question.

    PubMed

    Glanzman, David L

    2008-06-24

    A recent study shows that avoidance conditioning in the cephalopod Octopus vulgaris is mediated by long-term potentiation (LTP), a form of synaptic plasticity thought to be important in vertebrate associative learning. Thus, LTP appears to be an evolutionarily conserved learning mechanism.

  14. OCTOPUS--A Church-Based Sex Education Program for Teens and Parents.

    ERIC Educational Resources Information Center

    Jacknik, Michele; And Others

    1984-01-01

    Describes OCTOPUS (Open Communication Regarding Teenagers or Parents Understanding of Sexuality), which was established as a forum for family discussion within a church setting. The program was designed to enhance communication skills, convey information, and help teenagers acquire appropriate morals and values. Feedback from four churches…

  15. Dynamic model of the octopus arm. II. Control of reaching movements.

    PubMed

    Yekutieli, Yoram; Sagiv-Zohar, Roni; Hochner, Binyamin; Flash, Tamar

    2005-08-01

    The dynamic model of the octopus arm described in the first paper of this 2-part series was used here to investigate the neural strategies used for controlling the reaching movements of the octopus arm. These are stereotypical extension movements used to reach toward an object. In the dynamic model, sending a simple propagating neural activation signal to contract all muscles along the arm produced an arm extension with kinematic properties similar to those of natural movements. Control of only 2 parameters fully specified the extension movement: the amplitude of the activation signal (leading to the generation of muscle force) and the activation traveling time (the time the activation wave takes to travel along the arm). We found that the same kinematics could be achieved by applying activation signals with different activation amplitudes all exceeding some minimal level. This suggests that the octopus arm could use minimal amplitudes of activation to generate the minimal muscle forces required for the production of the desired kinematics. Larger-amplitude signals would generate larger forces that increase the arm's stability against perturbations without changing the kinematic characteristics. The robustness of this phenomenon was demonstrated by examining activation signals with either a constant or a bell-shaped velocity profile. Our modeling suggests that the octopus arm biomechanics may allow independent control of kinematics and resistance to perturbation during arm extension movements.

  16. Mapping of neurons in the gravity receptor system of the octopus statocyst by iontophoretic cobalt staining.

    PubMed

    Budelmann, B U; Wolff, H G

    1976-08-26

    The presence of uni-, bi- and multipolar neurons beneath the hair cell epithelium of the Octopus gravity receptor system has been demonstrated by iontophoretic cobalt staining. Counts give an average number of 1,940 neurons per macula. Whether the hair cells are primary of secondary sensory cells is discussed.

  17. Olfactory organ of Octopus vulgaris: morphology, plasticity, turnover and sensory characterization.

    PubMed

    Polese, Gianluca; Bertapelle, Carla; Di Cosmo, Anna

    2016-05-15

    The cephalopod olfactory organ was described for the first time in 1844 by von Kölliker, who was attracted to the pair of small pits of ciliated cells on each side of the head, below the eyes close to the mantle edge, in both octopuses and squids. Several functional studies have been conducted on decapods but very little is known about octopods. The morphology of the octopus olfactory system has been studied, but only to a limited extent on post-hatching specimens, and the only paper on adult octopus gives a minimal description of the olfactory organ. Here, we describe the detailed morphology of young male and female Octopus vulgaris olfactory epithelium, and using a combination of classical morphology and 3D reconstruction techniques, we propose a new classification for O. vulgaris olfactory sensory neurons. Furthermore, using specific markers such as olfactory marker protein (OMP) and proliferating cell nuclear antigen (PCNA) we have been able to identify and differentially localize both mature olfactory sensory neurons and olfactory sensory neurons involved in epithelium turnover. Taken together, our data suggest that the O. vulgaris olfactory organ is extremely plastic, capable of changing its shape and also proliferating its cells in older specimens. © 2016. Published by The Company of Biologists Ltd.

  18. D(--)-lactic acid and d(--)-lactate dehydrohgenase in octopus spermatozoa.

    PubMed

    Mann, T; Martin, A W; Thiersch, J B; Lutwak-Mann, C; Brooks, D E; Jones, R

    1974-08-02

    The spermatozoa of Octopus dofleini martini produce anaerobically D(-)-lactic acid and possess a very active D(-)-lactate dehydrogenase. In this respect, while resembling certain microorganisms, they differ strikingly from mammalian spermatozoa which produce L(+)-lactic acid and contain L(+)-lactate dehydrogenase.

  19. Dynamic octopus amphiphiles as powerful activators of DNA transporters: differential fragrance sensing and beyond.

    PubMed

    Montenegro, Javier; Bonvin, Pauline; Takeuchi, Toshihide; Matile, Stefan

    2010-12-17

    We report the design, synthesis and evaluation of dynamic "octopus" amphiphiles with emphasis on their efficiency as activators in synthetic membrane-based sensing systems. Previously, we found that the in situ treatment of charged hydrazides with hydrophobic aldehydes or ketones gives amphiphilic counterion activators of polyion transporters in lipid bilayers, and that their efficiency increases with the number of their hydrophobic tails. Herein, we expand this series to amphiphiles with one cationic head (guanidinium or ammonium) and four exchangeable hydrophobic tails. These results, with the highest number of tails reported to date, confirm that dynamic octopus amphiphiles provide access to maximal activity and selectivity. Odorants, such as muscone, carvone, or anisaldehyde are used to outline their usefulness in differential sensing systems that operate based on counterion-activated DNA transporters in fluorogenic vesicles. The enhanced ability of octopus amphiphiles to enable the discrimination of enantiomers as well as that of otherwise intractable ortho, meta, and para isomers and short cyclo-/alkyl tails is demonstrated. These findings identify dynamic octopus amphiphiles as being promising for application to differential sensing, "fragrant" cellular uptake, and slow release.

  20. Molecular characterization of a KIF3B-like kinesin gene in the testis of Octopus tankahkeei (Cephalopoda, Octopus).

    PubMed

    Dang, Ran; Zhu, Jun-Quan; Tan, Fu-Qing; Wang, Wei; Zhou, Hong; Yang, Wan-Xi

    2012-05-01

    KIF3B is known for maintaining and assembling cilia and flagellum. To date, the function of KIF3B and its relationship with KIF3A during spermiogenesis in the cephalopod Octopus tankahkeei remains unknown. In the present study, we characterized a gene encoding a homologue of rat KIF3B in the O. tankahkeei testis and examined its temporal and spatial expression pattern during spermiogenesis. The cDNA of KIF3B was obtained with degenerate and RACE PCR and the distribution pattern of ot-kif3b were observed with RT-PCR. The morphological development during spermiogenesis was illustrated by histological and transmission electron microscopy and mRNA expression of ot-kif3b was observed by in situ hybridization. The 2,365 nucleotides cDNA consisted of a 102 bp 5' untranslated region (UTR), a 2,208 bp open reading frame (ORF) encoding a protein of 736 amino acids, and a 55 bp 3' UTR. Multiple alignments revealed that the putative Ot-KIF3B shared 68, 68, 69, 68, and 67% identity with that of Homo sapiens, Mus musculus, Gallus gallus, Danio rerio, and Xenopus laevis, respectively, along with high identities with Ot-KIF3A in fundamental structures. Ot-kif3b transcripts appeared gradually in early spermatids, increased in intermediate spermatids and maximized in drastically remodeled and final spermatids. The kif3b gene is identified and its expression pattern is demonstrated for the first time in O. tankahkeei. Compared to ot-kif3a reported by our laboratory before, our data suggested that the putative heterodimeric motor proteins Ot-KIF3A/B may be involved in intraspermatic transport and might contribute to structural changes during spermiogenesis.

  1. The role of DNA methylation on Octopus vulgaris development and their perspectives

    PubMed Central

    Díaz-Freije, Eva; Gestal, Camino; Castellanos-Martínez, Sheila; Morán, Paloma

    2014-01-01

    DNA methylation is a common regulator of gene expression and development in mammalian and other vertebrate genomes. DNA methylation has been studied so far in a few bivalve mollusk species, finding a wide spectrum of levels. We focused our study in the common octopus, Octopus vulgaris, an important organism for neuroscience, physiology and ethology research as well as for human consumption. We aim to confirm the existence of DNA methylation in O. vulgaris and ultimately, if methylation plays a role in gene regulation during octopus development. We used a genome-wide approach, methylation-sensitive amplified polymorphism (MSAP), firstly in four different tissues from the same specimens from adult benthonic individuals to test whether gene expression is regulated by methylation. Secondly, we tested the hypothesis that methylation underlies development by assessing MSAP patters from paralarvae to adult developmental stages. Our data indicate that octopus genome is widely methylated since clear differences can be observed, and the methylation pattern changes with the development. The statistical analyses showed significant differences in methylation pattern between paralarvae, where higher internal cytosine methylation is observed, and the three other post-hatching stages. This suggests an important role of cytosine methylation during the first step of development, when major morphological changes take place. However, methylation seems to have little effect on gene expression during the benthonic phase, since no significant effect was revealed in the analyses of molecular variance (AMOVA) performed. Our observations highlight the importance of epigenetic mechanisms in the first developmental steps of the common octopus and opens new perspectives to overcome high mortality rate during paralarvae growth. Thus, better understanding the molecular regulation patterns could lead to new approaches that increase the efficiency of husbandry of this emergent species for

  2. The octopus genome and the evolution of cephalopod neural and morphological novelties.

    PubMed

    Albertin, Caroline B; Simakov, Oleg; Mitros, Therese; Wang, Z Yan; Pungor, Judit R; Edsinger-Gonzales, Eric; Brenner, Sydney; Ragsdale, Clifton W; Rokhsar, Daniel S

    2015-08-13

    Coleoid cephalopods (octopus, squid and cuttlefish) are active, resourceful predators with a rich behavioural repertoire. They have the largest nervous systems among the invertebrates and present other striking morphological innovations including camera-like eyes, prehensile arms, a highly derived early embryogenesis and a remarkably sophisticated adaptive colouration system. To investigate the molecular bases of cephalopod brain and body innovations, we sequenced the genome and multiple transcriptomes of the California two-spot octopus, Octopus bimaculoides. We found no evidence for hypothesized whole-genome duplications in the octopus lineage. The core developmental and neuronal gene repertoire of the octopus is broadly similar to that found across invertebrate bilaterians, except for massive expansions in two gene families previously thought to be uniquely enlarged in vertebrates: the protocadherins, which regulate neuronal development, and the C2H2 superfamily of zinc-finger transcription factors. Extensive messenger RNA editing generates transcript and protein diversity in genes involved in neural excitability, as previously described, as well as in genes participating in a broad range of other cellular functions. We identified hundreds of cephalopod-specific genes, many of which showed elevated expression levels in such specialized structures as the skin, the suckers and the nervous system. Finally, we found evidence for large-scale genomic rearrangements that are closely associated with transposable element expansions. Our analysis suggests that substantial expansion of a handful of gene families, along with extensive remodelling of genome linkage and repetitive content, played a critical role in the evolution of cephalopod morphological innovations, including their large and complex nervous systems.

  3. The octopus genome and the evolution of cephalopod neural and morphological novelties

    PubMed Central

    Albertin, Caroline B.; Simakov, Oleg; Mitros, Therese; Wang, Z. Yan; Pungor, Judit R.; Edsinger-Gonzalez, Eric; Brenner, Sydney; Ragsdale, Clifton W.; Rokhsar, Daniel S.

    2016-01-01

    Coleoid cephalopods (octopus, squid, and cuttlefish) are active, resourceful predators with a rich behavioral repertoire1. They have the largest nervous systems among the invertebrates2 and present other striking morphological innovations including camera-like eyes, prehensile arms, a highly derived early embryogenesis, and the most sophisticated adaptive coloration system among all animals1,3. To investigate the molecular bases of cephalopod brain and body innovations we sequenced the genome and multiple transcriptomes of the California two-spot octopus, Octopus bimaculoides. We found no evidence for hypothesized whole genome duplications in the octopus lineage4–6. The core developmental and neuronal gene repertoire of the octopus is broadly similar to that found across invertebrate bilaterians, except for massive expansions in two gene families formerly thought to be uniquely enlarged in vertebrates: the protocadherins, which regulate neuronal development, and the C2H2 superfamily of zinc finger transcription factors. Extensive mRNA editing generates transcript and protein diversity in genes involved in neural excitability, as previously described7, as well as in genes participating in a broad range of other cellular functions. We identified hundreds of cephalopod-specific genes, many of which showed elevated expression levels in such specialized structures as the skin, the suckers, and the nervous system. Finally, we found evidence for large-scale genomic rearrangements that are closely associated with transposable element expansions. Our analysis suggests that substantial expansion of a handful of gene families, along with extensive remodeling of genome linkage and repetitive content, played a critical role in the evolution of cephalopod morphological innovations, including their large and complex nervous systems. PMID:26268193

  4. Resonance Raman studies of the HOOP modes in octopus bathorhodopsin with deuterium-labeled retinal chromophores.

    PubMed

    Deng, H; Manor, D; Weng, G; Rath, P; Koutalos, Y; Ebrey, T; Gebhard, R; Lugtenburg, J; Tsuda, M; Callender, R H

    1991-05-07

    Resonance Raman spectra of the hydrogen out-of-plane (HOOP) vibrational modes in the retinal chromophore of octopus bathorhodopsin with deuterium label(s) along the polyene chain have been obtained. In clear contrast with bovine bathorhodopsin's HOOP modes, there are only two major HOOP bands at 887 and 940 cm-1 for octopus bathorhodopsin. On the basis of their isotopic shifts upon deuterium labeling, we have assigned the band at 887 cm-1 to C10H and C14H HOOP modes, and the band at 940 cm-1 to C11H = C12H Au-like HOOP mode. Except for a 26 cm-1 downward shift, the C11H = C12H Au-like wag appears to be little disturbed in octopus bathorhodopsin from the chromophore in solution since its changes upon deuterium labeling are close to those found in solution model-compound studies. We found also that the C10H and C14H HOOP wags are also similar to those in the model-compound studies. However, we have found that the interaction between the C7H and C8H HOOP internal coordinates of the chromophore in octopus bathorhodopsin is different from that of the chromophore in solution. The intensity of the C11H = C12H and the other HOOP modes suggests that the chromophore of octopus bathorhodopsin is somewhat torsionally distorted from a planar trans geometry. Importantly, a twist about C11 = C12 double bond is inferred. Such a twist breaks the local symmetry, resulting in the observation of the normally Raman-forbidden C11H = C12H Au-like HOOP mode. The twisted nature of the chromophore, semiquantitatively discussed here, likely affects the lambda max of the chromophore and its enthalpy.(ABSTRACT TRUNCATED AT 250 WORDS)

  5. Nuclear and mitochondrial markers reveal evidence for genetically segregated cryptic speciation in giant Pacific octopuses from Prince William Sound, Alaska

    USGS Publications Warehouse

    Toussaint, Rebecca K.; Scheel, David; Sage, G.K.; Talbot, S.L.

    2012-01-01

    Multiple species of large octopus are known from the north Pacific waters around Japan, however only one large species is known in the Gulf of Alaska (the giant Pacific octopus, Enteroctopus dofleini). Current taxonomy of E. dofleini is based on geographic and morphological characteristics, although with advances in genetic technology that is changing. Here, we used two mitochondrial genes (cytochrome b and cytochrome oxidase I), three nuclear genes (rhodopsin, octopine dehydrogenase, and paired-box 6), and 18 microsatellite loci for phylogeographic and phylogenetic analyses of octopuses collected from across southcentral and the eastern Aleutian Islands (Dutch Harbor), Alaska. Our results suggest the presence of a cryptic Enteroctopus species that is allied to, but distinguished from E. dofleini in Prince William Sound, Alaska. Existence of an undescribed and previously unrecognized taxon raises important questions about the taxonomy of octopus in southcentral Alaska waters.

  6. A learning and memory area in the octopus brain manifests a vertebrate-like long-term potentiation.

    PubMed

    Hochner, Binyamin; Brown, Euan R; Langella, Marina; Shomrat, Tal; Fiorito, Graziano

    2003-11-01

    Cellular mechanisms underlying learning and memory were investigated in the octopus using a brain slice preparation of the vertical lobe, an area of the octopus brain involved in learning and memory. Field potential recordings revealed long-term potentiation (LTP) of glutamatergic synaptic field potentials similar to that in vertebrates. These findings suggest that convergent evolution has led to the selection of similar activity-dependent synaptic processes that mediate complex forms of learning and memory in vertebrates and invertebrates.

  7. De novo transcriptome sequencing of the Octopus vulgaris hemocytes using Illumina RNA-Seq technology: response to the infection by the gastrointestinal parasite Aggregata octopiana.

    PubMed

    Castellanos-Martínez, Sheila; Arteta, David; Catarino, Susana; Gestal, Camino

    2014-01-01

    Octopus vulgaris is a highly valuable species of great commercial interest and excellent candidate for aquaculture diversification; however, the octopus' well-being is impaired by pathogens, of which the gastrointestinal coccidian parasite Aggregata octopiana is one of the most important. The knowledge of the molecular mechanisms of the immune response in cephalopods, especially in octopus is scarce. The transcriptome of the hemocytes of O. vulgaris was de novo sequenced using the high-throughput paired-end Illumina technology to identify genes involved in immune defense and to understand the molecular basis of octopus tolerance/resistance to coccidiosis. A bi-directional mRNA library was constructed from hemocytes of two groups of octopus according to the infection by A. octopiana, sick octopus, suffering coccidiosis, and healthy octopus, and reads were de novo assembled together. The differential expression of transcripts was analysed using the general assembly as a reference for mapping the reads from each condition. After sequencing, a total of 75,571,280 high quality reads were obtained from the sick octopus group and 74,731,646 from the healthy group. The general transcriptome of the O. vulgaris hemocytes was assembled in 254,506 contigs. A total of 48,225 contigs were successfully identified, and 538 transcripts exhibited differential expression between groups of infection. The general transcriptome revealed genes involved in pathways like NF-kB, TLR and Complement. Differential expression of TLR-2, PGRP, C1q and PRDX genes due to infection was validated using RT-qPCR. In sick octopuses, only TLR-2 was up-regulated in hemocytes, but all of them were up-regulated in caecum and gills. The transcriptome reported here de novo establishes the first molecular clues to understand how the octopus immune system works and interacts with a highly pathogenic coccidian. The data provided here will contribute to identification of biomarkers for octopus resistance against

  8. Skin lesion-associated pathogens from Octopus vulgaris: first detection of Photobacterium swingsii, Lactococcus garvieae and betanodavirus.

    PubMed

    Fichi, G; Cardeti, G; Perrucci, S; Vanni, A; Cersini, A; Lenzi, C; De Wolf, T; Fronte, B; Guarducci, M; Susini, F

    2015-07-23

    The common octopus Octopus vulgaris Cuvier, 1798 is extremely important in fisheries and is a useful protein source in most Mediterranean countries. Here we investigated pathogens associated with skin lesions in 9 naturally deceased specimens that included both cultured and wild common octopus. Within 30 min after death, each octopus was stored at 4°C and microbiologically examined within 24 h. Bacterial colonies, cultured from swabs taken from the lesions, were examined using taxonomical and biochemical analyses. Vibrio alginolyticus and V. parahaemolyticus were only isolated from cultured animals. A conventional PCR targeting the 16S ribosomal RNA (rRNA) gene and sequencing were performed on 2 bacterial isolates that remained unidentified after taxonomical and biochemical analysis. The sequence results indicated that the bacteria had a 99% identity with Lactococcus garvieae and Photobacterium swingsii. L. garvieae was confirmed using a specific PCR based on the 16S-23S rRNA internal transcribed spacer region, while P. swingsii was confirmed by phylogenetic analyses. Although all animals examined were found to be infected by the protozoan species Aggregata octopiana localised in the intestines, it was also present in skin lesions of 2 of the animals. Betanodavirus was detected in both cultured and wild individuals by cell culture, PCR and electron microscopy. These findings are the first report of L. garvieae and betanodavirus from skin lesions of common octopus and the first identification of P. swingsii both in octopus skin lesions and in marine invertebrates in Italy.

  9. Life history of the bathyal octopus Pteroctopus tetracirrhus (Mollusca, Cephalopoda) in the Mediterranean Sea

    NASA Astrophysics Data System (ADS)

    Quetglas, Antoni; Ordines, Francesc; González, María; Franco, Ignacio

    2009-08-01

    The life cycle of the deep-sea octopus Pteroctopus tetracirrhus was studied from monthly samples obtained throughout the year in different areas of the western Mediterranean (mainly around the Balearic Islands and along the coast of the Iberian Peninsula). A total of 373 individuals (205 females, 168 males) were analyzed; females ranged from 4.5 to 14.0 cm mantle length (ML) and males from 4.5 to 11.5 cm ML. There were few small-sized octopuses (<7 cm ML) in the samples, which might indicate that these individuals inhabit rocky grounds that are not accessible to trawlers or waters deeper than the maximum depth sampled (800 m). The species occurred more frequently around the Balearic Islands than along the Iberian Peninsula as they appeared in 20% and 7%, respectively, of the hauls in these areas. The octopus inhabits the lower continental shelf and upper slope in both areas, primarily between 200 and 500 m depth. Modal lengths were followed from autumn, when recruits were caught by trawlers, to summer, when reproduction took place. Females grew from 8 to 10 cm ML from winter to spring, but this modal size did not increase further in summer; males grew from 7 to 9 cm ML from winter to spring. The total disappearance of large individuals after summer suggests a life cycle lasting a single year. The evolution of the monthly mean sizes showed that the growth was best described by log-linear functions in both sexes. The length at first maturity was clearly higher in females (12 cm ML) than in males (8 cm ML). A total of 30 different prey items, belonging to four major taxonomic groups (crustaceans, osteichthyes, cephalopods and gastropods), were identified in the stomach contents. The diet of the octopus was based on crustaceans and teleosts, which accounted for 75% and 23% of the prey items, respectively. Cephalopods and gastropods were accessory prey as they only represented 1.6% and 0.7%, respectively, of the total. The octopus showed a marked preference for the

  10. Time Course of Metabolic Capacities in Paralarvae of the Common Octopus, Octopus vulgaris, in the First Stages of Life. Searching Biomarkers of Nutritional Imbalance

    PubMed Central

    Morales, Amalia E.; Cardenete, Gabriel; Hidalgo, M. Carmen; Garrido, Diego; Martín, M. Virginia; Almansa, Eduardo

    2017-01-01

    The culture of the common octopus (Octopus vulgaris) is promising since the species has a relatively short lifecycle, rapid growth, and high food conversion ratios. However, recent attempts at successful paralarvae culture have failed due to slow growth and high mortality rates. Establishing an optimal nutritional regime for the paralarvae seems to be the impeding step in successful culture methods. Gaining a thorough knowledge of food regulation and assimilation is essential for paralarvae survival and longevity under culture conditions. The aim of this study, then, was to elucidate the characteristic metabolic organization of octopus paralarvae throughout an ontogenic period of 12 days post-hatching, as well as assess the effect of diet enrichment with live prey containing abundant marine phospholipids. Our results showed that throughout the ontogenic period studied, an increase in anaerobic metabolism took place largely due to an increased dependence of paralarvae on exogenous food. Our studies showed that this activity was supported by octopine dehydrogenase activity, with a less significant contribution of lactate dehydrogenase activity. Regarding aerobic metabolism, the use of amino acids was maintained for the duration of the experiment. Our studies also showed a significant increase in the rate of oxidation of fatty acids from 6 days after-hatching. A low, although sustained, capacity for de novo synthesis of glucose from amino acids and glycerol was also observed. Regardless of the composition of the food, glycerol kinase activity significantly increased a few days prior to a massive mortality event. This could be related to a metabolic imbalance in the redox state responsible for the high mortality. Thus, glycerol kinase might be used as an effective nutritional and welfare biomarker. The studies in this report also revealed the important finding that feeding larvae with phospholipid-enriched Artemia improved animal viability and welfare, significantly

  11. Discovery of an Unexplored Protein Structural Scaffold of Serine Protease from Big Blue Octopus (Octopus cyanea): A New Prospective Lead Molecule.

    PubMed

    Panda, Subhamay; Kumari, Leena

    2017-01-01

    Serine proteases are a group of enzymes that hydrolyses the peptide bonds in proteins. In mammals, these enzymes help in the regulation of several major physiological functions such as digestion, blood clotting, responses of immune system, reproductive functions and the complement system. Serine proteases obtained from the venom of Octopodidae family is a relatively unexplored area of research. In the present work, we tried to effectively utilize comparative composite molecular modeling technique. Our key aim was to propose the first molecular model structure of unexplored serine protease 5 derived from big blue octopus. The other objective of this study was to analyze the distribution of negatively and positively charged amino acid over molecular modeled structure, distribution of secondary structural elements, hydrophobicity molecular surface analysis and electrostatic potential analysis with the aid of different bioinformatic tools. In the present study, molecular model has been generated with the help of I-TASSER suite. Afterwards the refined structural model was validated with standard methods. For functional annotation of protein molecule we used Protein Information Resource (PIR) database. Serine protease 5 of big blue octopus was analyzed with different bioinformatical algorithms for the distribution of negatively and positively charged amino acid over molecular modeled structure, distribution of secondary structural elements, hydrophobicity molecular surface analysis and electrostatic potential analysis. The functionally critical amino acids and ligand- binding site (LBS) of the proteins (modeled) were determined using the COACH program. The molecular model data in cooperation to other pertinent post model analysis data put forward molecular insight to proteolytic activity of serine protease 5, which helps in the clear understanding of procoagulant and anticoagulant characteristics of this natural lead molecule. Our approach was to investigate the octopus

  12. Combined Transcriptomic and Proteomic Analysis of the Posterior Salivary Gland from the Southern Blue-Ringed Octopus and the Southern Sand Octopus.

    PubMed

    Whitelaw, Brooke L; Strugnell, Jan M; Faou, Pierre; da Fonseca, Rute R; Hall, Nathan E; Norman, Mark; Finn, Julian; Cooke, Ira R

    2016-09-02

    This study provides comprehensive proteomic profiles from the venom producing posterior salivary glands of octopus (superorder Octopodiformes) species. A combined transcriptomic and proteomic approach was used to identify 1703 proteins from the posterior salivary gland of the southern blue-ringed octopus, Hapalochlaena maculosa and 1300 proteins from the posterior salivary gland of the southern sand octopus, Octopus kaurna. The two proteomes were broadly similar; clustering of proteins into orthogroups revealed 937 that were shared between species. Serine proteases were particularly diverse and abundant in both species. Other abundant proteins included a large number of secreted proteins, many of which had no known conserved domains, or homology to proteins with known function. On the basis of homology to known venom proteins, 23 putative toxins were identified in H. maculosa and 24 in O. kaurna. These toxins span nine protein families: CAP (cysteine rich secretory proteins, antigen 5, parthenogenesis related), chitinase, carboxylesterase, DNase, hyaluronidase, metalloprotease, phospholipase, serine protease and tachykinin. Serine proteases were responsible for 70.9% and 86.3% of putative toxin expression in H. maculosa and O. kaurna, respectively, as determined using intensity based absolute quantification (iBAQ) measurements. Phylogenetic analysis of the putative toxin serine proteases revealed a similar suite of diverse proteins present in both species. Posterior salivary gland composition of H. maculosa and O. kaurna differ in several key aspects. While O. kaurna expressed the proteinaceous neurotoxin, tachykinin, this was absent from H. maculosa, perhaps reflecting the acquisition of a potent nonproteinaceous neurotoxin, tetrodotoxin (TTX) produced by bacteria in the salivary glands of that species. The dispersal factor, hyaluronidase was particularly abundant in H. maculosa. Chitinase was abundant in both species and is believed to facilitate

  13. Formation of a Fluorous/Organic Biphasic Supramolecular Octopus Assembly for Enhanced Porphyrin Phosphorescence in Air

    DOE PAGES

    Yang, Chi; Arvapally, Ravi K.; Tekarli, Sammer M.; ...

    2015-03-03

    The trinuclear triangle-shaped system [tris{3,5-bis(heptafluoropropyl)-1,2,4-triazolatosilver(I)}] (1) and the multi-armed square-shaped metalloporphyrin PtOEP or the free porphyrin base H2OEP serve as excellent octopus hosts (OEP=2,3,7,8,12,13,17,18-octaethyl-21H,23H-porphine). Coupling of the fluorous/organic molecular octopi 1 and H2OEP or PtOEP by strong quadrupole-quadrupole and metal- interactions affords the supramolecular assemblies [1PtOEP] or [1H(2)OEP] (2a), which feature nanoscopic cavities surrounding the upper triangular and lower square cores. The fluorous/organic biphasic configuration of [1PtOEP] leads to an increase in the phosphorescence of PtOEP under ambient conditions. Guest molecules can be included in the biphasic double-octopus assembly in three different site-selective modes.

  14. A closed marine culture system for rearing Octopus joubini and other large-egged benthic octopods.

    PubMed

    Forsythe, J W; Hanlon, R T

    1980-04-01

    The system consists of 2 adjoining 150 litre aquaria, one functioning as the water-conditioning tank and the other as the principal rearing tank. Water quality remained high with biological and mechanical filtration, physical adsorption and ultraviolet-light disinfection taking place exclusively in the conditioning tank. The pH ranged from 7.58 to 8.00 and ammonia and nitrite levels never exceeded 0.004 mg/l and 0.198 mg/l, respectively. Nitrate levels were maintained at 40 mg/l or less with no adverse affects. Adult octopuses readily mated and females produced 50-150 eggs, with 95% hatching success. When fed small liver crabs, the octopus hatchlings were reared to sexual maturity either in groups or individually in about 120-150 days. Growth rates (4% bodyweight/day) and food conversion efficiences (30-40%) were as high as those obtained in open systems by previous workers.

  15. Microsatellite loci from the endemic Southern Ocean octopus Adelieledone polymorpha (Robson, 1930).

    PubMed

    Strugnell, Jan M; Allcock, A Louise; Watts, Phillip C

    2009-05-01

    To determine the pattern of spatial genetic structure in the endemic Southern Ocean octopus Adelieledone polymorpha, microsatellite loci were isolated from partial genomic libraries enriched for repetitive DNA motifs. Seven dinucleotide and two trinucleotide microsatellite loci were isolated successfully and levels of polymorphism were quantified in 34 individuals sampled from the Southern Ocean near South Georgia. No pairs of microsatellite loci were linked significantly; however, one locus deviated (P < 0.05) from Hardy-Weinberg equilibrium. Overall, the nine loci produced between five and 16 alleles, with observed and expected heterozygosities varying between 0.22 and 0.86 and between 0.21 and 0.94 respectively. This is the first description of microsatellite loci from an octopus endemic to the Southern Ocean, and these genetic markers are being used to quantify spatial structure within A. polymorpha.

  16. Coccidian infection may explain the differences in the life history of octopus host populations.

    PubMed

    Storero, Lorena P; Narvarte, Maite A

    2013-11-01

    The prevalence of coccidian parasites in three Octopus tehuelchus populations from San Matías Gulf (Patagonia, Argentina) is compared. The prevalence was similar between sexes, but varied between seasons (being highest during cold months) and sites. Islote Lobos had the highest prevalence (42.7-100%) followed by San Antonio Bay (0-66%) and El Fuerte (0-24.5%). Octopuses under 27 mm of dorsal mantle length showed a low prevalence (less than 50%), which increased with size. We hypothesize that the high prevalence of parasites, which affect the three populations differentially, could account for the observed variability in life-span and growth, size-frequency distributions, reproduction and densities of O. tehuelchus populations.

  17. Functional characterization on invertebrate and vertebrate tissues of tachykinin peptides from octopus venoms.

    PubMed

    Ruder, Tim; Ali, Syed Abid; Ormerod, Kiel; Brust, Andreas; Roymanchadi, Mary-Louise; Ventura, Sabatino; Undheim, Eivind A B; Jackson, Timothy N W; Mercier, A Joffre; King, Glenn F; Alewood, Paul F; Fry, Bryan G

    2013-09-01

    It has been previously shown that octopus venoms contain novel tachykinin peptides that despite being isolated from an invertebrate, contain the motifs characteristic of vertebrate tachykinin peptides rather than being more like conventional invertebrate tachykinin peptides. Therefore, in this study we examined the effect of three variants of octopus venom tachykinin peptides on invertebrate and vertebrate tissues. While there were differential potencies between the three peptides, their relative effects were uniquely consistent between invertebrate and vertebrae tissue assays. The most potent form (OCT-TK-III) was not only the most anionically charged but also was the most structurally stable. These results not only reveal that the interaction of tachykinin peptides is more complex than previous structure-function theories envisioned, but also reinforce the fundamental premise that animal venoms are rich resources of novel bioactive molecules, which are useful investigational ligands and some of which may be useful as lead compounds for drug design and development.

  18. Ontogeny of the digestive system of the Octopus bimaculatus paralarvae (Verril, 1883).

    PubMed

    López-Peraza, Diana Judith; Hernández-Rodríguez, Mónica; Barón-Sevilla, Benjamín

    2014-01-01

    The high mortalities registered in the larval stage during octopus culturing are mainly due to nutritional deficiencies of the food provided. To understand the cause of this problem, we studied the ontogenetic development of the digestive system of Octopus bimaculatus paralarvae. An egg batch was obtained from a gravid female collected in the Bay of Los Angeles, Baja California, Mexico, and it was incubated in the laboratory during the summer of 2011. We observed that the formation of the digestive system began at 33 days post-laying (DPL). The newly hatched paralarvae had already formed the organs involved in food ingestion and digestion, although it was not possible to know accurately their degree of maturity. The present research constitutes the first description at the histological level of the ontogenic development of the digestive system of the O. bimaculatus paralarvae. This serves as a basis for future studies of the digestive physiology of this species.

  19. Ciliated sensory cells and associated neurons in the lip of Octopus joubini Robson.

    PubMed

    Emery, D G

    1975-01-01

    The lip of Octopus joubini is a fleshy fold around the beak that is subdivided distally into finger-like papillae and overlayed by an uninterrupted noncellular cuticle. The muscular core of the lip has a high proportion of nervous tissue. The simple epithelium contains numerous ciliated sensory cells, especially in the papillae. In many of these cells the cilia lie deep within the cytoplasm and usually appear to extend toward the surface. Receptors with intracellular cilia also lie below the epithelium and send dendrites bearing cilia to the surface. Large unipolar interneurons that may receive synapses from the ciliated receptors lie in the musculature near the papillae. The sensory system of the octopus lip is more advanced than that of the squid, and it is very similar to that of Sepia. The relationship of these findings to the phylogeny and ecology of cephalopods is discussed.

  20. Centrifugal neurons of the octopus optic lobe cortex are immunopositive for calcitonin gene-related peptide.

    PubMed

    Suzuki, Hirohumi; Yamamoto, Toshiharu

    2002-05-10

    Distribution of calcitonin gene-related peptide (CGRP)-like substance in the optic lobe cortex and retina of the octopus was examined immunohistochemically. Wheat germ agglutinin (WGA), a retrograde-transporting marker, was also used to label the centrifugal neurons. CGRP-immunoreactive (CGRP-IR) somata were seen in the inner granular cell layer, but not in the outer granular cell layer or the retina. CGRP-IR fibers were seen not only in the optic lobe cortex, but also in the retinal nerve plexus. Retrogradely labeled somata were seen in the inner granular cell layer, but not in the outer granular cell layer. Immunohistochemical double staining indicated that WGA-labeled centrifugal neurons were immunopositive for CGRP. These results suggested that the centrifugal neurons in the octopus optic lobe cortex are CGRP-like peptide-containing neurons, and that the peptide may modulate photoreceptor cell functions.

  1. The gyri of the octopus vertical lobe have distinct neurochemical identities.

    PubMed

    Shigeno, Shuichi; Ragsdale, Clifton W

    2015-06-15

    The cephalopod vertical lobe is the largest learning and memory structure known in invertebrate nervous systems. It is part of the visual learning circuit of the central brain, which also includes the superior frontal and subvertical lobes. Despite the well-established functional importance of this system, little is known about neuropil organization of these structures and there is to date no evidence that the five longitudinal gyri of the vertical lobe, perhaps the most distinctive morphological feature of the octopus brain, differ in their connections or molecular identities. We studied the histochemical organization of these structures in hatchling and adult Octopus bimaculoides brains with immunostaining for serotonin, octopus gonadotropin-releasing hormone (oGNRH), and octopressin-neurophysin (OP-NP). Our major finding is that the five lobules forming the vertical lobe gyri have distinct neurochemical signatures. This is most prominent in the hatchling brain, where the median and mediolateral lobules are enriched in OP-NP fibers, the lateral lobule is marked by oGNRH innervation, and serotonin immunostaining heavily labels the median and lateral lobules. A major source of input to the vertical lobe is the superior frontal lobe, which is dominated by a neuropil of interweaving fiber bundles. We have found that this neuropil also has an intrinsic neurochemical organization: it is partitioned into territories alternately enriched or impoverished in oGNRH-containing fascicles. Our findings establish that the constituent lobes of the octopus superior frontal-vertical system have an intricate internal anatomy, one likely to reflect the presence of functional subsystems within cephalopod learning circuitry.

  2. Development of microsatellite markers to genetically differentiate populations of Octopus minor from Korea and China.

    PubMed

    Kang, Jung-Ha; Kim, Yi-Kyung; Park, Jung-Youn; An, Chel-Min; Jun, Je-Chun

    2012-08-01

    Of the more than 300 octopus species, Octopus minor is one of the most popular and economically important species in Eastern Asia, including Korea, along with O. vulgaris, O. ocellatus, and O. aegina. We developed 19 microsatellite markers from Octopus minor and eight polymorphic markers were developed to analyze the genetic diversity and relationships among four octopus populations from Korea and three from China. The number of alleles per locus varied from 10 to 49, and allelic richness per locus ranged from 2 to 16.4 across all populations. The average allele number among the populations was 11.1, with a minimum of 8.3 and a maximum of 13.6. The mean allelic richness was 8.7 in all populations. The Hardy-Weinberg equilibrium (HWE) test revealed significant deviation in 19 of the 56 single-locus sites, and null alleles were presumed in five of eight loci. The pairwise F ( ST ) values between populations from Korea and China differed significantly in all pairwise comparisons. The genetic distances between the China and Korea samples ranged from 0.161 to 0.454. The genetic distances among the populations from Korea ranged from 0.033 to 0.090, with an average of 0.062; those among populations from China ranged from 0.191 to 0.316, with an average of 0.254. The populations from Korea and China formed clearly separated into clusters via an unweighted pair group method with arithmetic mean dendrogram. Furthermore, a population from muddy flats on the western coast of the Korean Peninsula and one from a rocky area on Jeju Island formed clearly separated subclusters. An assignment test based on the allele distribution discriminated between the Korean and Chinese origins with 96.9 % accuracy.

  3. Octopus arm movements under constrained conditions: adaptation, modification and plasticity of motor primitives.

    PubMed

    Richter, Jonas N; Hochner, Binyamin; Kuba, Michael J

    2015-04-01

    The motor control of the eight highly flexible arms of the common octopus (Octopus vulgaris) has been the focus of several recent studies. Our study is the first to manage to introduce a physical constraint to an octopus arm and investigate the adaptability of stereotypical bend propagation in reaching movements and the pseudo-limb articulation during fetching. Subjects (N=6) were placed inside a transparent Perspex box with a hole at the center that allowed the insertion of a single arm. Animals had to reach out through the hole toward a target, to retrieve a food reward and fetch it. All subjects successfully adjusted their movements to the constraint without an adaptation phase. During reaching tasks, the animals showed two movement strategies: stereotypical bend propagation reachings, which were established at the hole of the Perspex box and variant waving-like movements that showed no bend propagations. During fetching movements, no complete pseudo-joint fetching was observed outside the box and subjects pulled their arms through the hole in a pull-in like movement. Our findings show that there is some flexibility in the octopus motor system to adapt to a novel situation. However, at present, it seems that these changes are more an effect of random choices between different alternative motor programs, without showing clear learning effects in the choice between the alternatives. Interestingly, animals were able to adapt the fetching movements to the physical constraint, or as an alternative explanation, they could switch the motor primitive fetching to a different motor primitive 'arm pulling'.

  4. Phylogenetic analysis of the hyperthermophilic pink filament community in Octopus Spring, Yellowstone National Park

    SciTech Connect

    Reysenbach, A.L.; Wickham, G.S.; Pace, N.R.

    1994-06-01

    This study uses a molecular phylogenetic approach to characterize the pink filament community at the outflow of Octopus Spring in Yellowstone National Park. The temperature range of the spring is from 84 to 88 C. The authors show that the pink filaments are most closely related to the hydrogen-oxidizing bacterium Aquifex pyrophilus and a close relative Hydrogenobacter thermophilus. 38 refs., 4 figs., 1 tab.

  5. Autoradiographic and biochemical analysis of photoreceptor membrane renewal in Octopus retina.

    PubMed

    Robles, L J; Cabebe, C S; Aguilo, J A; Anyakora, P A; Bok, D

    1984-02-01

    Using autoradiographic and biochemical methods, we have demonstrated the renewal of light-sensitive membranes and photopigments in Octopus visual cells. After the injection of Octopus with [3H]leucine, electron microscope autoradiography revealed an intracellular pathway similar to that in vertebrates for the synthesis and transport of nascent protein from the inner segments to the rhabdomes. However, migration of labelled protein from synthetic sites to the light-sensitive rhabdomes took longer in Octopus than the equivalent process in vertebrates. Biochemical analysis of [3H]leucine-labelled retinas identified some of the labelled protein observed in autoradiographs of the rhabdomes as the visual pigment, rhodopsin. We have shown that retinochrome, a second photopigment in cephalopod retinas, is also renewed. Biochemical analysis 8 h after injection of [3H]leucine revealed heavy labelling of this photoprotein. Light microscope autoradiography of Octopus retina 8 h after injection of [3H]retinol showed labelling of both the rhabdomes and the myeloid bodies of the inner segments. Biochemical data gathered 8 h after injection of [3H]retinol indicated chromophore addition to both rhodopsin and retinochrome with retinochrome being more heavily labelled than rhodopsin. Thus, silver grains observed over the rhabdomes and inner segments could arise from one or both photopigments. These data suggest that retinal is stored in the myeloid bodies of the photoreceptor inner segments. Retinal could then be transferred, perhaps via retinochrome, to newly synthesized opsin before the visual pigment is assembled into new rhabdomeric membranes. Alternatively, retinochrome may serve to transport retinal from the myeloid bodies to the rhabdomes to regenerate rhodopsin as previously proposed.

  6. Time-dependent density-functional theory in massively parallel computer architectures: the OCTOPUS project.

    PubMed

    Andrade, Xavier; Alberdi-Rodriguez, Joseba; Strubbe, David A; Oliveira, Micael J T; Nogueira, Fernando; Castro, Alberto; Muguerza, Javier; Arruabarrena, Agustin; Louie, Steven G; Aspuru-Guzik, Alán; Rubio, Angel; Marques, Miguel A L

    2012-06-13

    Octopus is a general-purpose density-functional theory (DFT) code, with a particular emphasis on the time-dependent version of DFT (TDDFT). In this paper we present the ongoing efforts to achieve the parallelization of octopus. We focus on the real-time variant of TDDFT, where the time-dependent Kohn-Sham equations are directly propagated in time. This approach has great potential for execution in massively parallel systems such as modern supercomputers with thousands of processors and graphics processing units (GPUs). For harvesting the potential of conventional supercomputers, the main strategy is a multi-level parallelization scheme that combines the inherent scalability of real-time TDDFT with a real-space grid domain-partitioning approach. A scalable Poisson solver is critical for the efficiency of this scheme. For GPUs, we show how using blocks of Kohn-Sham states provides the required level of data parallelism and that this strategy is also applicable for code optimization on standard processors. Our results show that real-time TDDFT, as implemented in octopus, can be the method of choice for studying the excited states of large molecular systems in modern parallel architectures.

  7. Delayed reaction after an octopus bite showing a giant cell-rich granulomatous dermatitis/panniculitis.

    PubMed

    Misago, Noriyuki; Inoue, Takuya; Narisawa, Yutaka

    2008-11-01

    Adequate clinical data and a sufficient workup, in addition to the histopathological findings, are frequently required to make a correct diagnosis of granulomatous dermatitis/panniculitis. These lesions with an unexpected etiology may include delayed hypersensitivity granulomatous reactions to various factors, such as metals or marine animal injuries. A 50-year-old male presented with multiple subcutaneous nodules on his right forearm 1 month following an octopus bite at his right wrist. After the disappearance of these lesions, which responded well to low-dose oral prednisone, another type of skin lesion characterized by small, numerous papules reappeared on his right forearm. Histopathologically, a specimen from a subcutaneous nodule showed mostly lobular granulomatous panniculitis, which showed an extensive diffuse infiltrate composed of numerous multinucleated giant cells and epithelioid cells intermingling with lymphocytes and eosinophils. A specimen from a papule that subsequently developed disclosed a diffuse granulomatous dermatitis composed of similar cells and also showed granuloma annulare-like features. This case is considered to be a delayed reaction after an octopus bite showing an unusual giant cell-rich granulomatous dermatitis/panniculitis. Octopus bites should therefore be included among the marine animal injuries, which cause a delayed-type reaction with granulomatous dermatitis/panniculitis.

  8. An octopus-bioinspired solution to movement and manipulation for soft robots.

    PubMed

    Calisti, M; Giorelli, M; Levy, G; Mazzolai, B; Hochner, B; Laschi, C; Dario, P

    2011-09-01

    Soft robotics is a challenging and promising branch of robotics. It can drive significant improvements across various fields of traditional robotics, and contribute solutions to basic problems such as locomotion and manipulation in unstructured environments. A challenging task for soft robotics is to build and control soft robots able to exert effective forces. In recent years, biology has inspired several solutions to such complex problems. This study aims at investigating the smart solution that the Octopus vulgaris adopts to perform a crawling movement, with the same limbs used for grasping and manipulation. An ad hoc robot was designed and built taking as a reference a biological hypothesis on crawling. A silicone arm with cables embedded to replicate the functionality of the arm muscles of the octopus was built. This novel arm is capable of pushing-based locomotion and object grasping, mimicking the movements that octopuses adopt when crawling. The results support the biological observations and clearly show a suitable way to build a more complex soft robot that, with minimum control, can perform diverse tasks.

  9. Octopuses use a human-like strategy to control precise point-to-point arm movements.

    PubMed

    Sumbre, Germán; Fiorito, Graziano; Flash, Tamar; Hochner, Binyamin

    2006-04-18

    One of the key problems in motor control is mastering or reducing the number of degrees of freedom (DOFs) through coordination. This problem is especially prominent with hyper-redundant limbs such as the extremely flexible arm of the octopus. Several strategies for simplifying these control problems have been suggested for human point-to-point arm movements. Despite the evolutionary gap and morphological differences, humans and octopuses evolved similar strategies when fetching food to the mouth. To achieve this precise point-to-point-task, octopus arms generate a quasi-articulated structure based on three dynamic joints. A rotational movement around these joints brings the object to the mouth . Here, we describe a peripheral neural mechanism-two waves of muscle activation propagate toward each other, and their collision point sets the medial-joint location. This is a remarkably simple mechanism for adjusting the length of the segments according to where the object is grasped. Furthermore, similar to certain human arm movements, kinematic invariants were observed at the joint level rather than at the end-effector level, suggesting intrinsic control coordination. The evolutionary convergence to similar geometrical and kinematic features suggests that a kinematically constrained articulated limb controlled at the level of joint space is the optimal solution for precise point-to-point movements.

  10. Calcium currents correlate with oocyte maturation during the reproductive cycle in Octopus vulgaris.

    PubMed

    Cuomo, Annunziata; Di Cristo, Carlo; Paolucci, Marina; Di Cosmo, Anna; Tosti, Elisabetta

    2005-03-01

    Using the whole-cell voltage clamp technique, we have studied the Ca2+ currents and the steady-state conductance during different oocyte growth stages and during the reproductive cycle of the female of Octopus vulgaris. Evidence is presented that L-type Ca2+ currents are high in small pre-vitellogenic oocytes (80-150 microm diameter) and significantly lower in early vitellogenic oocytes (180-300 microm diameter). Similarly, a significant decrease of the steady-state conductance occurred from the pre to early- vitellogenic oocytes. Octopus oocytes showed larger Ca2+ currents in the reproductive rather than non-reproductive periods. These data indicates that ion and L-type Ca2+ currents play a role in oocyte growth and cytoplasmic maturation, and possibly in preparing the plasma membrane to the interaction with the spermatozoon. By using fluorescent microscopy, we show that oocytes from 80 to 400 microm diameter have the large germinal vesicle characteristic of the immature oocytes. In subsequent stages of growth (up to 1000 microm diameter) the nucleus is no more visible and the metaphase spindle appears. These data demonstrate that Octopus vulgaris oocytes are arrested in the first meiotic prophase up to the early-vitellogenic stage and resume meiosis at this stage up to a second block presumably in metaphase I. We discuss a possible role for progesterone as the hormonal stimulus for the first prophase-metaphase meiotic transition.

  11. Time-dependent density-functional theory in massively parallel computer architectures: the octopus project

    NASA Astrophysics Data System (ADS)

    Andrade, Xavier; Alberdi-Rodriguez, Joseba; Strubbe, David A.; Oliveira, Micael J. T.; Nogueira, Fernando; Castro, Alberto; Muguerza, Javier; Arruabarrena, Agustin; Louie, Steven G.; Aspuru-Guzik, Alán; Rubio, Angel; Marques, Miguel A. L.

    2012-06-01

    Octopus is a general-purpose density-functional theory (DFT) code, with a particular emphasis on the time-dependent version of DFT (TDDFT). In this paper we present the ongoing efforts to achieve the parallelization of octopus. We focus on the real-time variant of TDDFT, where the time-dependent Kohn-Sham equations are directly propagated in time. This approach has great potential for execution in massively parallel systems such as modern supercomputers with thousands of processors and graphics processing units (GPUs). For harvesting the potential of conventional supercomputers, the main strategy is a multi-level parallelization scheme that combines the inherent scalability of real-time TDDFT with a real-space grid domain-partitioning approach. A scalable Poisson solver is critical for the efficiency of this scheme. For GPUs, we show how using blocks of Kohn-Sham states provides the required level of data parallelism and that this strategy is also applicable for code optimization on standard processors. Our results show that real-time TDDFT, as implemented in octopus, can be the method of choice for studying the excited states of large molecular systems in modern parallel architectures.

  12. Immunolocalization of choline acetyltransferase of common type in the central brain mass of Octopus vulgaris.

    PubMed

    Casini, A; Vaccaro, R; D'Este, L; Sakaue, Y; Bellier, J P; Kimura, H; Renda, T G

    2012-07-19

    Acetylcholine, the first neurotransmitter to be identified in the vertebrate frog, is widely distributed among the animal kingdom. The presence of a large amount of acetylcholine in the nervous system of cephalopods is well known from several biochemical and physiological studies. However, little is known about the precise distribution of cholinergic structures due to a lack of a suitable histochemical technique for detecting acetylcholine. The most reliable method to visualize the cholinergic neurons is the immunohistochemical localization of the enzyme choline acetyltransferase, the synthetic enzyme of acetylcholine. Following our previous study on the distribution patterns of cholinergic neurons in the Octopus vulgaris visual system, using a novel antibody that recognizes choline acetyltransferase of the common type (cChAT), now we extend our investigation on the octopus central brain mass. When applied on sections of octopus central ganglia, immunoreactivity for cChAT was detected in cell bodies of all central brain mass lobes with the notable exception of the subfrontal and subvertical lobes. Positive varicosed nerves fibers where observed in the neuropil of all central brain mass lobes.

  13. Learning the inverse kinetics of an octopus-like manipulator in three-dimensional space.

    PubMed

    Giorelli, M; Renda, F; Calisti, M; Arienti, A; Ferri, G; Laschi, C

    2015-05-13

    This work addresses the inverse kinematics problem of a bioinspired octopus-like manipulator moving in three-dimensional space. The bioinspired manipulator has a conical soft structure that confers the ability of twirling around objects as a real octopus arm does. Despite the simple design, the soft conical shape manipulator driven by cables is described by nonlinear differential equations, which are difficult to solve analytically. Since exact solutions of the equations are not available, the Jacobian matrix cannot be calculated analytically and the classical iterative methods cannot be used. To overcome the intrinsic problems of methods based on the Jacobian matrix, this paper proposes a neural network learning the inverse kinematics of a soft octopus-like manipulator driven by cables. After the learning phase, a feed-forward neural network is able to represent the relation between manipulator tip positions and forces applied to the cables. Experimental results show that a desired tip position can be achieved in a short time, since heavy computations are avoided, with a degree of accuracy of 8% relative average error with respect to the total arm length.

  14. Purification and characterization of an alpha-macroglobulin proteinase inhibitor from the mollusc Octopus vulgaris.

    PubMed Central

    Thøgersen, I B; Salvesen, G; Brucato, F H; Pizzo, S V; Enghild, J J

    1992-01-01

    The cell-free haemolymph of the mollusc Octopus vulgaris inhibited the proteolytic activity of the thermolysin against the high-molecular-mass substrate hide powder azure. The purified inhibitor was a glycoprotein composed of two identical 180 kDa disulphide-linked subunits. In addition to the inhibition of the metalloproteinase thermolysin, the protein inhibited the serine proteinases human neutrophil elastase, pig pancreatic elastase, bovine chymotrypsin, bovine trypsin and the cysteine proteinase papain. A fraction of the proteinase-inhibitor complex resisted dissociation after denaturation indicating that some of the proteinase molecules became covalently bound. The nucleophile beta-aminopropionitrile decreased the covalent binding of proteinases to the Octopus vulgaris protein, suggesting that this interaction is mediated by an internal thiol ester; the reactivity and the amino acid sequence flanking the reactive residues of the putative thiol ester were consistent with this hypothesis. Bound trypsin remained active against the low-molecular-mass chromatogenic substrate H-D-Pro-Phe-Arg p-nitroanilide and was protected from inhibition by active-site-directed protein inhibitors of trypsin; however, the bound trypsin was readily inhibited by small synthetic inhibitors. This indicates that the inhibition of proteinases is accomplished by steric hindrance. The proteinase-inhibitory activity of this protein is characteristic of inhibition by mammalian alpha-macroglobulins and the presence of a putative thiol ester suggests that the Octopus vulgaris proteinase inhibitor is a homologue of human alpha 2-macroglobulin. Images Fig. 1. Fig. 2. Fig. 3. Fig. 5. PMID:1379044

  15. Immunolocalization of choline acetyltransferase of common type in the central brain mass of Octopus vulgaris

    PubMed Central

    Casini, A.; Vaccaro, R.; D'Este, L.; Sakaue, Y.; Bellier, J.P.; Kimura, H.; Renda, T.G.

    2012-01-01

    Acetylcholine, the first neurotransmitter to be identified in the vertebrate frog, is widely distributed among the animal kingdom. The presence of a large amount of acetylcholine in the nervous system of cephalopods is well known from several biochemical and physiological studies. However, little is known about the precise distribution of cholinergic structures due to a lack of a suitable histochemical technique for detecting acetylcholine. The most reliable method to visualize the cholinergic neurons is the immunohistochemical localization of the enzyme choline acetyltransferase, the synthetic enzyme of acetylcholine. Following our previous study on the distribution patterns of cholinergic neurons in the Octopus vulgaris visual system, using a novel antibody that recognizes choline acetyltransferase of the common type (cChAT), now we extend our investigation on the octopus central brain mass. When applied on sections of octopus central ganglia, immunoreactivity for cChAT was detected in cell bodies of all central brain mass lobes with the notable exception of the subfrontal and subvertical lobes. Positive varicosed nerves fibers where observed in the neuropil of all central brain mass lobes. PMID:23027350

  16. Calretinin distribution in the octopus brain: an immunohistochemical and in situ hybridization histochemical analysis.

    PubMed

    Altobelli, Giovanna G; Cimini, Vincenzo

    2007-02-09

    The distribution of calretinin containing neurons examined by in situ hybridization mapping was compared with that obtained by immunocytochemistry in the brain of octopus. Results revealed a close correspondence between the two types of investigations. Western blot analysis disclosed a 29 kDa protein immunostained with anti-calretinin antibody. Calretinin containing neurons were localized mainly in the cortex of octopus lobes, including the vertical, frontal, basal, buccal, palliovisceral, pedal and branchial, with variations of staining intensity and density of immunoreactive cells. The amacrine cells surrounding calretinin containing neuronal bodies of the cortex were also labeled unlike the glial cells. The close correspondence of blotting analysis, immunocytochemistry and in situ hybridization indicates with no doubt that calretinin, like other calcium-binding proteins previously studied, is also present in the nervous system of cephalopods. Furthermore, although recent findings localize calretinin also in endocrine glands, the presence of this calcium-binding protein in the brain of octopus indicates that calretinin appeared early in the phylogeny as a neuronal protein already in invertebrates.

  17. The role of copper and quaternary structure on the conformational properties of Octopus vulgaris hemocyanin.

    PubMed

    Ricchelli, F; Jori, G; Tallandini, L; Zatta, P; Beltramini, M; Salvato, B

    1984-12-01

    Some structural properties of Octopus vulgaris hemocyanin have been investigated by fluorescence spectroscopy. The three-dimensional structure of Octopus hemocyanin is remarkably tight, resulting in a deep burial of almost all the tryptophyl residues of the protein. The hemocyanin conformation has been studied in the two main aggregation states (11 S, 50 S) of the protein, and with respect to the presence or absence of copper in the active site. Upon changing the pH of the solution, Octopus hemocyanin in the 50 S aggregation state can assume at least three different conformations. During the transition between each conformation the fluorescence quantum yield changes, but the environment of tryptophans does not change. Dissociation of the protein from 50 S to 11 S strongly enhances its susceptibility toward denaturating agents such as pH or temperature, and modifies the effects of fluorescence quenchers such as acrylamide. Moreover, these effects are more pronounced when copper is removed from the active site. A comparative analysis of the results shows that the subunit-subunit interactions exerted within the 50 S species are more important in the maintenance of the conformational stability than the copper ions present in the active sites. This behavior can be accounted for by the large amount of Ca(II) ions linked to 50 S hemocyanin.

  18. Purification and characterization of an alpha-macroglobulin proteinase inhibitor from the mollusc Octopus vulgaris.

    PubMed

    Thøgersen, I B; Salvesen, G; Brucato, F H; Pizzo, S V; Enghild, J J

    1992-07-15

    The cell-free haemolymph of the mollusc Octopus vulgaris inhibited the proteolytic activity of the thermolysin against the high-molecular-mass substrate hide powder azure. The purified inhibitor was a glycoprotein composed of two identical 180 kDa disulphide-linked subunits. In addition to the inhibition of the metalloproteinase thermolysin, the protein inhibited the serine proteinases human neutrophil elastase, pig pancreatic elastase, bovine chymotrypsin, bovine trypsin and the cysteine proteinase papain. A fraction of the proteinase-inhibitor complex resisted dissociation after denaturation indicating that some of the proteinase molecules became covalently bound. The nucleophile beta-aminopropionitrile decreased the covalent binding of proteinases to the Octopus vulgaris protein, suggesting that this interaction is mediated by an internal thiol ester; the reactivity and the amino acid sequence flanking the reactive residues of the putative thiol ester were consistent with this hypothesis. Bound trypsin remained active against the low-molecular-mass chromatogenic substrate H-D-Pro-Phe-Arg p-nitroanilide and was protected from inhibition by active-site-directed protein inhibitors of trypsin; however, the bound trypsin was readily inhibited by small synthetic inhibitors. This indicates that the inhibition of proteinases is accomplished by steric hindrance. The proteinase-inhibitory activity of this protein is characteristic of inhibition by mammalian alpha-macroglobulins and the presence of a putative thiol ester suggests that the Octopus vulgaris proteinase inhibitor is a homologue of human alpha 2-macroglobulin.

  19. Properties of the flavoenzyme D-aspartate oxidase from Octopus vulgaris.

    PubMed

    Tedeschi, G; Negri, A; Ceciliani, F; Ronchi, S; Vetere, A; D'Aniello, G; D'Aniello, A

    1994-08-17

    The properties of D-aspartate oxidase from Octopus vulgaris (EC 1.4.3.1) have been investigated. The protein is a monomer of M(r) 37,000 containing one mol flavin/mol protein. The enzyme as isolated exists at least in two forms, one containing FAD and the other, which is catalytically inactive, probably containing 6-OH-FAD, as inferred from the absorption spectrum of the enzyme. An additional form of the enzyme, as far as the nature of the coenzyme is concerned, has been detected in the purified enzyme and shown to derive from the form originally containing FAD. The modulation of the coenzyme reactivity exerted by Octopus D-aspartate oxidase, as studied by spectrophotometric techniques, conforms to the one expected for an enzyme belonging to the oxidase class of flavoproteins. Structural investigations show similarities in both the amino-acid composition and the N-terminal amino-acid sequence to bovine D-aspartate oxidase and porcine D-amino-acid oxidase. In summary, the general properties of the enzyme from Octopus vulgaris closely resemble those of the enzyme from beef kidney. Moreover, kinetic analyses suggest that two active-site residues with pKa of 7.1 and 9.1 are critical for catalysis, and that the ionization of such residues has different effects on the catalytic activity depending whether mono- or dicarboxylic D-amino acids are used as substrate.

  20. A method for isolating RNA from metabolically active bacterial flora associated with octopus.

    PubMed

    de la Cruz-Leyva, M C; Zamudio-Maya, M; Corona-Cruz, A I; González-de la Cruz, J U; Rojas-Herrera, R

    2011-07-01

    Development of a method for the isolation and purification of metagenomic RNA (mgRNA) from the ectopic bacterial flora of octopus. Modifications were made to the methods of Valenzuela-Avendaño et al. (Plant Mol Biol Rep, 2005, 23, 199a) and Chomczynski and Sacchi (Anal Biochem, 1987, 162, 156) to develop a protocol based on chemical lysis with Trizol. This proposed protocol effectively isolated mgRNA. The resulting bacterial RNA transcripts were amplified with universal primers directed to the hypervariable regions of the 16S rRNA gene by complementary DNA synthesis. Protocol efficacy in the study of metabolically active bacterial flora was proven using DGGE, which produced a banding pattern that recovered sequences mainly related to the Vibrionaceae family. The analysed samples were clearly complex, and the proposed protocol was proven to effectively isolate mgRNA from the metabolically active bacterial flora associated with octopus. This is the first protocol proposed for the isolation of bacterial mgRNA that allows identification and study of metabolically active bacterial flora associated with octopus. This is an important step forward in understanding and controlling the microbial community of this economically important fishery resource, aimed at detecting its potentially pathogenic bacteria. © 2011 The Authors. Letters in Applied Microbiology © 2011 The Society for Applied Microbiology.

  1. Soft-robotic arm inspired by the octopus: II. From artificial requirements to innovative technological solutions.

    PubMed

    Mazzolai, B; Margheri, L; Cianchetti, M; Dario, P; Laschi, C

    2012-06-01

    Soft robotics is a current focus in robotics research because of the expected capability of soft robots to better interact with real-world environments. As a point of inspiration in the development of innovative technologies in soft robotics, octopuses are particularly interesting 'animal models'. Octopus arms have unique biomechanical capabilities that combine significant pliability with the ability to exert a great deal of force, because they lack rigid structures but can change and control their degree of stiffness. The octopus arm motor capability is a result of the peculiar arrangement of its muscles and the properties of its tissues. These special abilities have been investigated by the authors in a specific study dedicated to identifying the key principles underlying these biological functions and deriving engineering requirements for robotics solutions. This paper, which is the second in a two-part series, presents how the identified requirements can be used to create innovative technological solutions, such as soft materials, mechanisms and actuators. Experiments indicate the ability of these proposed solutions to ensure the same performance as in the biological model in terms of compliance, elongation and force. These results represent useful and relevant components of innovative soft-robotic systems and suggest their potential use to create a new generation of highly dexterous, soft-bodied robots.

  2. Combined effect of vacuum-packaging and oregano essential oil on the shelf-life of Mediterranean octopus (Octopus vulgaris) from the Aegean Sea stored at 4 degrees C.

    PubMed

    Atrea, I; Papavergou, A; Amvrosiadis, I; Savvaidis, I N

    2009-04-01

    The present study evaluated the use of vacuum packaging (alone) or with addition of oregano essential oil (EO), as an antimicrobial treatment for shelf-life extension of fresh Mediterranean octopus stored under refrigeration for a period of 23 days. Four different treatments were tested: A, control sample; under aerobic storage in the absence of oregano essential oil; VP, under vacuum packaging in the absence of oregano essential oil; and VO1, VO2, treated samples with oregano essential oil 0.2 and 0.4% (v/w), respectively, under VP. Of all the microorganisms enumerated, Pseudomonas spp., H2S-producing bacteria and lactic acid bacteria (LAB) were the groups that prevailed in octopus samples, irrespective of antimicrobial treatment. With regard to the chemical freshness indices determined, thiobarbituric acid (TBA) values were low in all octopus samples, as could have been expected from the low fat content of the product. Both trimethylamine nitrogen (TMA-N) and total volatile basic nitrogen (TVB-N) values of oregano treated under VP octopus samples were significantly lower compared to control samples during the entire refrigerated storage period. Based primarily on sensory evaluation (odor), the use of VP, VO1 and VO2 extended the shelf-life of fresh Mediterranean octopus by ca. 3, 11 and 20 days, respectively.

  3. Total lipids and fatty acids composition of the coastal and the deep-sea common octopus (Octopus vulgaris) populations: a comparative study.

    PubMed

    Ben-Youssef, Saoussen; Selmi, Salah; Ezzeddine-Najai, Sofia; Sadok, Saloua

    2008-01-01

    The aim of this work was to investigate biochemical differences between Octopus vulgaris caught off costal zone and from the deep-sea of the Golf of Gabès (South coast of Tunisia). In both fishing grounds, octopus total lipids constituted almost 1.5% of wet tissue showing no significant difference (p < 0.05). The percentage distribution of fatty acids was not significantly different, neither between males and females, nor between both areas. Polyunsaturated fatty acids constituted about 50 % of the total fatty acids. Docosahexaenoic (DHA; C22:6 omega 3), eicosapentaenoic (EPA; C20:5 omega 3) and the arachidonic acids (C20:4) were the most important of this group with percentages of 25, 14 and 10% respectively. The saturated fraction constituted almost 30% of the total fatty acids. The most dominant saturated fatty acids were palmitic acid (C16:0) and stearic acid (C18:0), with 18% and 7% respectively. The monounsaturated content was found to contribute only 10% of the total fatty acids. Most of the monounsaturated fat was present as oleic acid (C18:1) and palmitoleic acid (C16:1) with 2.5% and 1.5% respectively. The presence of arachidonic acid in substantial proportions with an omega 3 to omega 6 ratios of 3.9 to 1 is of special interest because of the role of cephalopods in the traditional Mediterranean diet.

  4. Neuropeptide Y-immunoreactive neuronal system and colocalization with FMRFamide in the optic lobe and peduncle complex of the octopus (Octopus vulgaris).

    PubMed

    Suzuki, Hirohumi; Yamamoto, Toshiharu; Nakagawa, Miho; Uemura, Haruko

    2002-02-01

    The distribution of neuropeptide Y (NPY)-like immunoreactivity and its colocalization with FMRFamide were investigated in the optic lobe and peduncle complex of the octopus ( Octopus vulgaris) by using immunohistochemical techniques. In the optic lobe cortex, NPY-immunoreactive (NPY-IR) fibers were observed in the plexiform layer, although no NPY-IR somata were observed in the outer or inner granular cell layers. In the optic lobe medulla, NPY-IR somata were seen in the cell islands, and abundant NPY-IR varicose fibers were observed in the neuropil. Most of the NPY-IR structures in the medulla showed FMRFamide-like immunoreactivity. In the peduncle lobe, abundant NPY-IR and FMRFamide-IR (NPY/FMRF-IR) varicose fibers were seen in the basal zone neuropil of the peduncle lobe. In the olfactory lobe, NPY/FMRF-IR varicose fibers were also abundant in the neuropil of the three lobules. NPY/FMRF-IR somata, with processes running to various neuropils, were scattered in the median and posterior lobules. In the optic gland, many NPY/FMRF-IR varicose fibers formed a honeycomb pattern. These observations suggest that NPY/FMRF-IR neurons in the optic lobes participate in the modulation of visual information and that those in the optic gland are involved in the regulation of endocrine function.

  5. OCTOPUS-LIKE 2, a novel player in Arabidopsis root and vascular development, reveals a key role for OCTOPUS family genes in root metaphloem sieve tube differentiation.

    PubMed

    Ruiz Sola, M Aguila; Coiro, Mario; Crivelli, Simona; Zeeman, Samuel C; Schmidt Kjølner Hansen, Signe; Truernit, Elisabeth

    2017-09-06

    Protophloem and metaphloem sieve tubes are essential for transporting carbohydrates and signalling molecules towards sink tissues. OCTOPUS (OPS) was previously identified as an important regulator of protophloem differentiation in Arabidopsis roots. Here, we investigated the role of OCTOPUS-LIKE 2 (OPL2), a gene homologous to OPS. OPL2 expression patterns were analysed, and functional equivalence of OPS and OPL2 was tested. Mutant and double mutant phenotypes were investigated. OPS and OPL2 displayed overlapping expression patterns and a high degree of functional overlap. A mutation in OPL2 revealed redundant functions of OPS and OPL2 in developmental processes in which OPS was known to play a role, notably cotyledon vascular patterning and protophloem development. Moreover, we also uncovered redundant roles for OPS and OPL2 in leaf vascular patterning and, most interestingly, metaphloem sieve tube differentiation. Our results reveal a novel OPS-like protein that, together with OPS, is an important regulator of vascular patterning, root growth and phloem development. OPS and OPL2 are the first genes identified that play a role in metaphloem sieve tube differentiation. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

  6. Gonad development during the early life of Octopus maya (Mollusca: Cephalopoda).

    PubMed

    Avila-Poveda, Omar Hernando; Colin-Flores, Rafael Francisco; Rosas, Carlos

    2009-02-01

    Gonad development during the early life of Octopus maya is described in terms of histological, morphometric, oocytes growth, and somatic-oocyte relationship data obtained from octopus cultured at the UMDI-UNAM, in Sisal, Yucatan, Mexico. This study is the first publication on gonad development during the early life of Octopus maya. A total of 83 O. maya specimens were used; their sizes ranged from 6.5 to 76 mm of total length (TL), 4 to 28 mm of dorsal mantle length (DML), 2.5 to 20 mm of ventral mantle length (VML), and 0.0180 to 7.2940 g of fixed body weight (fBW). Animals were weighed and measured only after preservation. A loss of 10% of living weight was estimated for juvenile octopuses after formalin preservation. The relation of length to weight (VML, DML, TL/fBW) pooled for both sexes had a strong positive correlation (r), as shown by a potential power function that was quite close to 1. Compound images were produced from numerous microscopic fields. The histological examination revealed that, 4 months after hatching, male octopus (24.5 mm DML and 7.2940 g fBW) were in gonad stages 2 (maturing) to 3 (mature), with spermatogonia and spermatocytes in the tubule wall and abundant spermatids and spermatozoa in the central lumen of the seminiferous tubules, suggesting the occurrence of different phases of gonad development at different maturity stages. In contrast, females (22.5 mm DML and 4.8210 g fBW) at the same time since hatching were immature (stage 1), with many oogonia, few oocytes, and germinal epithelium. This suggests that males reach maturity earlier than females, indicating a probable onset of maturity for males at around 4 months of culture or 8 g of wet body weight. Our results indicate the possibility that the size-at-weight can be recognized early with a degree of certainty that allows the sexes to be separated for culture purposes; but more detailed studies on reproduction in relation to endocrinology and nutrition are needed.

  7. Identification and immunolocalization of actin cytoskeletal components in light- and dark-adapted octopus retinas.

    PubMed

    De Velasco, B; Martinez, J M; Ochoa, G H; Miller, A M; Clark, Y M; Matsumoto, B; Robles, L J

    1999-06-01

    Photoreceptors in the octopus retina are of the rhabdomeric type, with rhabdomeres arising from the plasma membrane on opposite sides of the cylindrical outer segment. Each rhabdomere microvillus has an actin filament core, but other actin-binding proteins have not been identified. We used immunoblotting techniques to identify actin-binding proteins in octopus retinal extracts and immunofluorescence microscopy to localize the same proteins in fixed tissue. Antibodies directed against alpha-actinin and vinculin recognized single protein bands on immunoblots of octopus retinal extract with molecular weights comparable to the same proteins in other tissues. Anti-filamin identified two closely spaced bands similar in molecular weight to filamin in other species. Antibodies to the larger of the Drosophila ninaC gene products, p174, identified two bands lower in molecular weight than p174. Anti-villin localized a band that was significantly less in molecular weight than villin found in other cells. Epifluorescence and confocal microscopy were used to map the location of the same actin-binding proteins in dark- and light-adapted octopus photoreceptors and other retinal cells. Antibodies to most of the actin-binding proteins showed heavy staining of the photoreceptor proximal/supportive cell region accompanied by rhabdom membrane and rhabdom tip staining, although subtle differences were detected with individual antibodies. In dark-adapted retinas anti-alpha-actinin stained the photoreceptor proximal/supportive cell region where an extensive junctional complex joins these two cell types, but in the light, immunoreactivity extended above the junctional complex into the rhabdom bases. Most antibodies densely stained the rhabdom tips but anti-villin exhibited a striated pattern of localization at the tips. We believe that the actin-binding proteins identified in the octopus retina may play a significant role in the formation of new rhabdomere microvilli in the dark. We

  8. Voltage-activated calcium currents in octopus cells of the mouse cochlear nucleus.

    PubMed

    Bal, Ramazan; Oertel, Donata

    2007-12-01

    Octopus cells, neurons in the most posterior and dorsal part of the mammalian ventral cochlear nucleus, convey the timing of synchronous firing of auditory nerve fibers to targets in the contralateral superior paraolivary nucleus and ventral nucleus of the lateral lemniscus. The low input resistances and short time constants at rest that arise from the partial activation of a large, low-voltage-activated K(+) conductance (g(KL)) and a large mixed-cation, hyperpolarization-activated conductance (g(h)) enable octopus cells to detect coincident firing of auditory nerve fibers with exceptional temporal precision. Octopus cells fire conventional, Na(+) action potentials but a voltage-sensitive Ca(2+) conductance was also detected. In this study, we explore the nature of that calcium conductance under voltage-clamp. Currents, carried by Ca(2+) or Ba(2+) and blocked by 0.4 mM Cd(2+), were activated by depolarizations positive to -50 mV and peaked at -23 mV. At -23 mV they reached 1.1 +/- 0.1 nA in the presence of 5 mM Ca(2+) and 1.6 +/- 0.1 nA in 5 mM Ba(2+). Ten micromolar BAY K 8644, an agonist of high-voltage-activated L-type channels, enhanced I(Ba) by 63 +/- 11% (n = 8) and 150 microM nifedipine, an antagonist of L-type channels, reduced the I(Ba) by 65 +/- 5% (n = 5). Meanwhile, 0.5 microM omega-Agatoxin IVA, an antagonist of P/Q-type channels, or 1 microM omega-conotoxin GVIA, an antagonist of N-type channels, suppressed I(Ba) by 15 +/- 4% (n = 5) and 9 +/- 4% (n = 5), respectively. On average 16% of the current remained in the presence of the cocktail of blockers, indicative of the presence of R-type channels. Together these experiments show that octopus cells have a depolarization-sensitive g(Ca) that is largely formed from L-type Ca(2+) channels and that P/Q-, N-, and R-type channels are expressed at lower levels in octopus cells.

  9. Voltage-activated Calcium Currents in Octopus Cells of the Mouse Cochlear Nucleus

    PubMed Central

    Bal, Ramazan

    2007-01-01

    Octopus cells, neurons in the most posterior and dorsal part of the mammalian ventral cochlear nucleus, convey the timing of synchronous firing of auditory nerve fibers to targets in the contralateral superior paraolivary nucleus and ventral nucleus of the lateral lemniscus. The low input resistances and short time constants at rest that arise from the partial activation of a large, low-voltage-activated K+ conductance (gKL) and a large mixed-cation, hyperpolarization-activated conductance (gh) enable octopus cells to detect coincident firing of auditory nerve fibers with exceptional temporal precision. Octopus cells fire conventional, Na+ action potentials but a voltage-sensitive Ca2+ conductance was also detected. In this study, we explore the nature of that calcium conductance under voltage-clamp. Currents, carried by Ca2+ or Ba2+ and blocked by 0.4 mM Cd2+, were activated by depolarizations positive to −50 mV and peaked at −23 mV. At −23 mV they reached 1.1 ± 0.1 nA in the presence of 5 mM Ca2+ and 1.6 ± 0.1 nA in 5 mM Ba2+. Ten micromolar BAY K 8644, an agonist of high-voltage-activated L-type channels, enhanced IBa by 63 ± 11% (n = 8) and 150 μM nifedipine, an antagonist of L-type channels, reduced the IBa by 65 ± 5% (n = 5). Meanwhile, 0.5 μM ω-Agatoxin IVA, an antagonist of P/Q-type channels, or 1 μM ω-conotoxin GVIA, an antagonist of N-type channels, suppressed IBa by 15 ± 4% (n = 5) and 9 ± 4% (n = 5), respectively. On average 16% of the current remained in the presence of the cocktail of blockers, indicative of the presence of R-type channels. Together these experiments show that octopus cells have a depolarization-sensitive gCa that is largely formed from L-type Ca2+ channels and that P/Q-, N-, and R-type channels are expressed at lower levels in octopus cells. PMID:17710492

  10. Persistent Contamination of Octopuses and Mussels with Lipophilic Shellfish Toxins during Spring Dinophysis Blooms in a Subtropical Estuary

    PubMed Central

    Mafra, Luiz L.; Lopes, Daiana; Bonilauri, Vanessa C.; Uchida, Hajime; Suzuki, Toshiyuki

    2015-01-01

    This study investigates the occurrence of diarrhetic shellfish toxins (DSTs) and their producing phytoplankton species in southern Brazil, as well as the potential for toxin accumulation in co-occurring mussels (Perna perna) and octopuses (Octopus vulgaris). During the spring in 2012 and 2013, cells of Dinophysis acuminata complex were always present, sometimes at relatively high abundances (max. 1143 cells L−1), likely the main source of okadaic acid (OA) in the plankton (max. 34 ng L−1). Dinophysis caudata occurred at lower cell densities in 2013 when the lipophilic toxins pectenotoxin-2 (PTX-2) and PTX-2 seco acid were detected in plankton and mussel samples. Here, we report for the first time the accumulation of DSTs in octopuses, probably linked to the consumption of contaminated bivalves. Perna perna mussels were consistently contaminated with different DSTs (max. 42 µg kg−1), and all octopuses analyzed (n = 5) accumulated OA in different organs/tissues: digestive glands (DGs) > arms > gills > kidneys > stomach + intestine. Additionally, similar concentrations of 7-O-palmytoyl OA and 7-O-palmytoly dinophysistoxin-1 (DTX-1) were frequently detected in the hepatopancreas of P. perna and DGs of O. vulgaris. Therefore, octopuses can be considered a potential vector of DSTs to both humans and top predators such as marine mammals. PMID:26096277

  11. Persistent Contamination of Octopuses and Mussels with Lipophilic Shellfish Toxins during Spring Dinophysis Blooms in a Subtropical Estuary.

    PubMed

    Mafra, Luiz L; Lopes, Daiana; Bonilauri, Vanessa C; Uchida, Hajime; Suzuki, Toshiyuki

    2015-06-18

    This study investigates the occurrence of diarrhetic shellfish toxins (DSTs) and their producing phytoplankton species in southern Brazil, as well as the potential for toxin accumulation in co-occurring mussels (Perna perna) and octopuses (Octopus vulgaris). During the spring in 2012 and 2013, cells of Dinophysis acuminata complex were always present, sometimes at relatively high abundances (max. 1143 cells L-1), likely the main source of okadaic acid (OA) in the plankton (max. 34 ng L-1). Dinophysis caudata occurred at lower cell densities in 2013 when the lipophilic toxins pectenotoxin-2 (PTX-2) and PTX-2 seco acid were detected in plankton and mussel samples. Here, we report for the first time the accumulation of DSTs in octopuses, probably linked to the consumption of contaminated bivalves. Perna perna mussels were consistently contaminated with different DSTs (max. 42 µg kg-1), and all octopuses analyzed (n = 5) accumulated OA in different organs/tissues: digestive glands (DGs) > arms > gills > kidneys > stomach + intestine. Additionally, similar concentrations of 7-O-palmytoyl OA and 7-O-palmytoly dinophysistoxin-1 (DTX-1) were frequently detected in the hepatopancreas of P. perna and DGs of O. vulgaris. Therefore, octopuses can be considered a potential vector of DSTs to both humans and top predators such as marine mammals.

  12. Tuberculoventral neurons project to the multipolar cell area but not to the octopus cell area of the posteroventral cochlear nucleus.

    PubMed

    Wickesberg, R E; Whitlon, D; Oertel, D

    1991-11-15

    Tuberculoventral neurons in the deep layer of the dorsal cochlear nucleus (DCN) provide frequency-specific inhibition to neurons in the anteroventral cochlear nucleus (AVCN) of the mouse (Wickesberg and Oertel, '88, '90). The present experiments examine the projection from the deep DCN to the posteroventral cochlear nucleus (PVCN). Horseradish peroxidase (HRP) injections into the PVCN reveal that the multipolar cell area, but not the octopus cell area, is innervated by neurons in the deep layer of the DCN. Injections into the multipolar cell area, in the rostral and ventral PVCN, labeled neurons across the entire rostrocaudal extent of the deep DCN. The labeled tuberculoventral neurons generally lay within the band of labeled auditory nerve terminals in the DCN. Injections of HRP into the octopus cell area, in the dorsal caudal PVCN, labeled almost no cells within the band of auditory nerve fiber terminals that were labeled by the same injection. The inhibition from tuberculoventral neurons onto ventral cochlear nucleus (VCN) neurons is likely to be mediated by glycine (Wickesberg and Oertel, '90). Slices of the cochlear nuclear complex were immunolabeled by an antibody against glycine conjugated with glutaraldehyde to bovine serum albumin (Wenthold et al., '87). Glycine-like immunoreactivity was found throughout the DCN, the AVCN and the multipolar cell area, but there was little labeling in the octopus cell area. This finding provides independent evidence that tuberculoventral neurons do not innervate the octopus cell area and indicates that the octopus cell area is anatomically and functionally distinct.

  13. Microdistribution of tetrodotoxin in two species of blue-ringed octopuses (Hapalochlaena lunulata and Hapalochlaena fasciata) detected by fluorescent immunolabeling.

    PubMed

    Williams, Becky L; Stark, Michael R; Caldwell, Roy L

    2012-12-01

    Blue-ringed octopuses (genus Hapalochlaena) possess the potent neurotoxin tetrodotoxin (TTX). We examined the microdistribution of TTX in ten tissues of Hapalochlaena lunulata and Hapalochlaena fasciata by immunolabeling for fluorescent light microscopy (FLM). We visualized TTX throughout the posterior salivary gland, but the toxin was concentrated in cells lining the secretory tubules within the gland. Tetrodotoxin was present just beneath the epidermis of the integument (mantle and arms) and also concentrated in channels running through the dermis. This was suggestive of a TTX transport mechanism in the blood of the octopus, which would also explain the presence of the toxin in the blood-rich brachial hearts, gills, nephridia, and highly vascularized Needham's sac (testes contents). We also present the first report of TTX in any cephalopod outside of the genus Hapalochlaena. A specimen of Octopus bocki from French Polynesia contained a small amount of TTX in the digestive gland.

  14. Genetic structure of Octopus vulgaris (Cephalopoda, Octopodidae) in the central Mediterranean Sea inferred from the mitochondrial COIII gene.

    PubMed

    Fadhlaoui-Zid, Karima; Knittweis, Leyla; Aurelle, Didier; Nafkha, Chaala; Ezzeddine, Soufia; Fiorentino, Fabio; Ghmati, Hisham; Ceriola, Luca; Jarboui, Othman; Maltagliati, Ferruccio

    2012-01-01

    The polymorphism of the mitochondrial gene cytochrome oxidase III was studied in the Mediterranean octopus, Octopus vulgaris Cuvier, 1797. A total of 202 specimens from seven sampling sites were analysed with the aim of elucidating patterns of genetic structure in the central Mediterranean Sea and to give an insight into the phylogeny of the Octopus genus. Phylogenetic analyses showed that individuals from the central Mediterranean belong to the O. vulgaris species whose limits should nevertheless be clarified. Concerning genetic structure, two high-frequency haplotypes were present in all locations. The overall genetic divergence (Φ(ST)=0.05, P<0.05) indicated a significant genetic structuring in the study area and an AMOVA highlighted a significant break between western and eastern Mediterranean basins (Φ(CT)=0.094, P<0.05). Possible explanations for the observed patterns of genetic structuring are discussed with reference to their relevance for fisheries management.

  15. Multiple-electrode radiofrequency ablations using Octopus® electrodes in an in vivo porcine liver model.

    PubMed

    Lee, E S; Lee, J M; Kim, W S; Choi, S H; Joo, I; Kim, M; Yoo, D H; Yoo, R-E; Han, J K; Choi, B I

    2012-09-01

    The objective of this study was to determine the in vivo efficacy of radiofrequency ablation (RFA) in porcine liver using Octopus® electrodes for creating a large coagulation compared with RFA using clustered electrodes. A total of 39 coagulations were created using a 200-W generator and clustered electrodes or Octopus electrodes during laparotomy in 19 pigs. Radiofrequency was applied to the livers using four protocols: (1) Group A-1, monopolar mode using a clustered electrode (n=11); (2) Group A-2, monopolar mode using an Octopus electrode (n=11); (3) Group B-1, consecutive monopolar mode using three, clustered electrodes (n=8); and (4) Group B-2, switching monopolar mode using two Octopus electrodes (n=9). The energy efficiency, shape, diameters (D) and volume (V) of the coagulation volume were compared in each of the two groups. The mean maximum D and V of the coagulations in Group A-2 (4.7 cm and 33.1 cm(3), respectively) were significantly larger than those in Group A-1 (4.1 cm and 20.3 cm(3), respectively) (p<0.05). Furthermore, the mean minimum D, maximum D and V of the coagulations in Group B-2 were significantly larger than those in Group B-1, i.e. 5.3 vs 4.0 cm, 6.6 vs 4.9 cm and 66.9 vs 30.2 cm(3), respectively (p<0.05). The energy efficiencies were also significantly higher in Groups A-2 and B-2 than in Groups A-1 and B-1 (p<0.05). The Octopus electrodes were more efficient for creating a large ablation zone than clustered electrodes, and the efficacy of RFA with Octopus electrodes can be amplified in the switching monopolar mode.

  16. How nervous systems evolve in relation to their embodiment: what we can learn from octopuses and other molluscs.

    PubMed

    Hochner, Binyamin

    2013-01-01

    Cephalopods such as the octopus show the most advanced behavior among invertebrates, which they accomplish with an exceptionally flexible body plan. In this review I propose that the embodied organization approach, developed by roboticists to design efficient autonomous robots, is useful for understanding the evolution and development of the efficient adaptive interaction of animals with their environment, using the octopus as the leading example. The embodied organization approach explains adaptive behavior as emerging from the continuous dynamical and reciprocal physical and informational interactions between four elements: the controller, the mechanical and the sensory systems and the environment. In contrast to hierarchical organization, in embodied organization, self-organization processes can take part in the emergence of the adaptive properties. I first discuss how the embodiment concept explains covariation of body form, nervous system organization, and level of behavioral complexity using the Mollusca as an example. This is an ideal phylum to test such a qualitative correlation between body/brain/behavior, because they show the greatest variations of body plan within a single phylum. In some cases the covariation of nervous system and body structure seems to arise independently of close phylogenetic relationships. Next, I dwell on the octopus as an ideal model to test the embodiment concept within a single biological system. Here, the unusual body morphology of the octopus exposes the uniqueness of the four components comprising the octopus' embodiment. Considering together the results from behavioral, physiological, anatomical, and motor control research suggests that these four elements mutually influence each other. It is this mutual interactions and self-organization which have led to their unique evolution and development to create the unique and highly efficient octopus embodiment.

  17. The pKa of the protonated Schiff bases of gecko cone and octopus visual pigments.

    PubMed Central

    Liang, J; Steinberg, G; Livnah, N; Sheves, M; Ebrey, T G; Tsuda, M

    1994-01-01

    A visual pigment is composed of retinal bound to its apoprotein by a protonated Schiff base linkage. Light isomerizes the chromophore and eventually causes the deprotonation of this Schiff base linkage at the meta II stage of the bleaching cycle. The meta II intermediate of the visual pigment is the active form of the pigment that binds to and activates the G protein transducin, starting the visual cascade. The deprotonation of the Schiff base is mandatory for the formation of meta II intermediate. We studied the proton binding affinity, pKa, of the Schiff base of both octopus rhodopsin and the gecko cone pigment P521 by spectral titration. Several fluorinated retinal analogs have strong electron withdrawing character around the Schiff base region and lower the Schiff base pKa in model compounds. We regenerated octopus and gecko visual pigments with these fluorinated and other retinal analogs. Experiments on these artificial pigments showed that the spectral changes seen upon raising the pH indeed reflected the pKa of the Schiff base and not the denaturation of the pigment or the deprotonation of some other group in the pigment. The Schiff base pKa is 10.4 for octopus rhodopsin and 9.9 for the gecko cone pigment. We also showed that although the removal of Cl- ions causes considerable blue-shift in the gecko cone pigment P521, it affects the Schiff base pKa very little, indicating that the lambda max of visual pigment and its Schiff base pKa are not tightly coupled. PMID:7948697

  18. Chemical Tools of Octopus maya during Crab Predation Are Also Active on Conspecifics

    PubMed Central

    Pech-Puch, Dawrin; Cruz-López, Honorio; Canche-Ek, Cindy; Campos-Espinosa, Gabriela; García, Elpidio; Mascaro, Maite; Rosas, Carlos; Chávez-Velasco, Daniel; Rodríguez-Morales, Sergio

    2016-01-01

    Octopus maya is a major socio-economic resource from the Yucatán Peninsula in Mexico. In this study we report for the first time the chemical composition of the saliva of O. maya and its effect on natural prey, i.e. the blue crab (Callinectes sapidus), the crown conch snail (Melongena corona bispinosa), as well as conspecifics. Salivary posterior glands were collected from octopus caught by local fishers and extracted with water; this extract paralyzed and predigested crabs when it was injected into the third pereiopod. The water extract was fractionated by membrane ultrafiltration with a molecular weight cut-off of 3kDa leading to a metabolic phase (>3kDa) and a neurotoxic fraction (<3kDa). The neurotoxic fraction injected in the crabs caused paralysis and postural changes. Crabs recovered to their initial condition within two hours, which suggests that the effects of the neurotoxic fraction were reversible. The neurotoxic fraction was also active on O. maya conspecifics, partly paralyzing and sedating them; this suggests that octopus saliva might be used among conspecifics for defense and for reduction of competition. Bioguided separation of the neurotoxic fraction by chromatography led to a paralysis fraction and a relaxing fraction. The paralyzing activity of the saliva was exerted by amino acids, while the relaxing activity was due to the presence of serotonin. Prey-handling studies revealed that O. maya punctures the eye or arthrodial membrane when predating blue crabs and uses the radula to bore through crown conch shells; these differing strategies may help O. maya to reduce the time needed to handle its prey. PMID:26895025

  19. Chemical Tools of Octopus maya during Crab Predation Are Also Active on Conspecifics.

    PubMed

    Pech-Puch, Dawrin; Cruz-López, Honorio; Canche-Ek, Cindy; Campos-Espinosa, Gabriela; García, Elpidio; Mascaro, Maite; Rosas, Carlos; Chávez-Velasco, Daniel; Rodríguez-Morales, Sergio

    2016-01-01

    Octopus maya is a major socio-economic resource from the Yucatán Peninsula in Mexico. In this study we report for the first time the chemical composition of the saliva of O. maya and its effect on natural prey, i.e. the blue crab (Callinectes sapidus), the crown conch snail (Melongena corona bispinosa), as well as conspecifics. Salivary posterior glands were collected from octopus caught by local fishers and extracted with water; this extract paralyzed and predigested crabs when it was injected into the third pereiopod. The water extract was fractionated by membrane ultrafiltration with a molecular weight cut-off of 3 kDa leading to a metabolic phase (>3 kDa) and a neurotoxic fraction (<3 kDa). The neurotoxic fraction injected in the crabs caused paralysis and postural changes. Crabs recovered to their initial condition within two hours, which suggests that the effects of the neurotoxic fraction were reversible. The neurotoxic fraction was also active on O. maya conspecifics, partly paralyzing and sedating them; this suggests that octopus saliva might be used among conspecifics for defense and for reduction of competition. Bioguided separation of the neurotoxic fraction by chromatography led to a paralysis fraction and a relaxing fraction. The paralyzing activity of the saliva was exerted by amino acids, while the relaxing activity was due to the presence of serotonin. Prey-handling studies revealed that O. maya punctures the eye or arthrodial membrane when predating blue crabs and uses the radula to bore through crown conch shells; these differing strategies may help O. maya to reduce the time needed to handle its prey.

  20. Distribution of tubulin, kinesin, and dynein in light- and dark-adapted octopus retinas.

    PubMed

    Martinez, J M; Elfarissi, H; De Velasco, B; Ochoa, G H; Miller, A M; Clark, Y M; Matsumoto, B; Robles, L J

    2000-01-01

    Cephalopod retinas exhibit several responses to light and dark adaptation, including rhabdom size changes, photopigment movements, and pigment granule migration. Light- and dark-directed rearrangements of microfilament and microtubule cytoskeletal transport pathways could drive these changes. Recently, we localized actin-binding proteins in light-/dark-adapted octopus rhabdoms and suggested that actin cytoskeletal rearrangements bring about the formation and degradation of rhabdomere microvilli subsets. To determine if the microtubule cytoskeleton and associated motor proteins control the other light/dark changes, we used immunoblotting and immunocytochemical procedures to map the distribution of tubulin, kinesin, and dynein in dorsal and ventral halves of light- and dark-adapted octopus retinas. Immunoblots detected alpha- and beta-tubulin, dynein intermediate chain, and kinesin heavy chain in extracts of whole retinas. Epifluorescence and confocal microscopy showed that the tubulin proteins were distributed throughout the retina with more immunoreactivity in retinas exposed to light. Kinesin localization was heavy in the pigment layer of light- and dark-adapted ventral retinas but was less prominent in the dorsal region. Dynein distribution also varied in dorsal and ventral retinas with more immunoreactivity in light- and dark-adapted ventral retinas and confocal microscopy emphasized the granular nature of this labeling. We suggest that light may regulate the distribution of microtubule cytoskeletal proteins in the octopus retina and that position, dorsal versus ventral, also influences the distribution of motor proteins. The microtubule cytoskeleton is most likely involved in pigment granule migration in the light and dark and with the movement of transport vesicles from the photoreceptor inner segments to the rhabdoms.

  1. What drives seasonal fluctuations of body condition in a semelparous income breeder octopus?

    NASA Astrophysics Data System (ADS)

    Quetglas, Antoni; Ordines, Francesc; Valls, Maria

    2011-09-01

    The vast majority of modern cephalopods is single-season breeders, or semelparous in the strict sense, that die soon after the reproduction takes place. Individual body condition in these marine invertebrates is expected to be highly affected by reproduction because: 1) the gonad weight of females, which represents <1% of body weight when immature, increases up to 20-50% during maturation; and 2) octopus females reduce or even cease their food intake during breeding. Based on this expectation, we analysed the interrelationship between condition and reproduction in the temperate octopus Eledone cirrhosa. Results from a previous work using biochemical analyses showed that reproduction in this species is not fuelled by stored reserves (capital breeder), but by food intakes (income breeder). Since income breeders depend strongly on food resources, the effect of several environmental variables related to food availability such as primary production, sea temperature (ST) and river discharges were also analysed. Condition showed a marked intrannual cycle independently of the sex and, noteworthy, the maturity stage. Given that immature individuals are not expected to display seasonal fluctuations in body condition related to maturation, these results preclude reproduction as a driving factor for the observed circannual cycle. Condition was significantly correlated with all the environmental variables analysed, except with ST at the depths where the species lives. Although this last result also precludes concurrent ST as a driving factor of body condition, those correlations suggest that condition might display an intrinsic seasonal cycle, as many other life-history traits in most species such as reproduction, migration or moulting. Finally, there also remains the possibility that condition in this octopus species is determined genetically, as has been reported in recent studies across different taxonomical groups.

  2. Composition and metabolism of phospholipids in Octopus vulgaris and Sepia officinalis hatchlings.

    PubMed

    Reis, Diana B; Acosta, Nieves G; Almansa, Eduardo; Tocher, Douglas R; Andrade, José P; Sykes, António V; Rodríguez, Covadonga

    2016-10-01

    The objective of the present study was to characterise the fatty acid (FA) profiles of the major phospholipids, of Octopus vulgaris and Sepia officinalis hatchlings, namely phosphatidylcholine (PC), phosphatidylserine (PS), phosphatidylinositol (PI) and phosphatidylethanolamine (PE); and to evaluate the capability of both cephalopod species on dietary phospholipid remodelling. Thus, O. vulgaris and S. officinalis hatchlings were in vivo incubated with 0.3μM of L-∝-1-palmitoyl-2-[1-(14)C]arachidonyl-PC or L-∝-1-palmitoyl-2-[1-(14)C]arachidonyl-PE. Octopus and cuttlefish hatchlings phospholipids showed a characteristic FA profiles with PC presenting high contents of 16:0 and 22:6n-3 (DHA); PS having high 18:0, DHA and 20:5n-3 (EPA); PI a high content of saturated FA; and PE showing high contents of DHA and EPA. Interestingly, the highest content of 20:4n-6 (ARA) was found in PE rather than PI. Irrespective of the phospholipid in which [1-(14)C]ARA was initially bound (either PC or PE), the esterification pattern of [1-(14)C]ARA in octopus lipids was similar to that found in their tissues with high esterification of this FA into PE. In contrast, in cuttlefish hatchlings [1-(14)C]ARA was mainly recovered in the same phospholipid that was provided. These results showed a characteristic FA profiles in the major phospholipids of the two species, as well as a contrasting capability to remodel dietary phospholipids, which may suggest a difference in phospholipase activities. Copyright © 2016 Elsevier Inc. All rights reserved.

  3. Neuromuscular system of the flexible arm of the octopus: physiological characterization.

    PubMed

    Matzner, H; Gutfreund, Y; Hochner, B

    2000-03-01

    The octopus arm is an outstanding example of an efficient boneless and highly flexible appendage. We have begun characterizing the neuromuscular system of the octopus arm in both innervated muscle preparations and dissociated muscle cells. Functionally antagonistic longitudinal and transverse muscle fibers showed no differences in membrane properties and mode of innervation. The muscle cells are excitable but have a broad range of linear membrane properties. They are electrotonically very compact so that localized synaptic inputs can control the membrane potential of the entire muscle cell. Three distinct excitatory neuronal inputs to each arm muscle cell were identified; their reversal potentials were extrapolated to be about -10 mV. These appear to be cholinergic as they are blocked by hexamethonium, D-tubocurarine, and atropine. Two inputs have low quantal amplitude (1-7 mV) and slow rise times (4-15 ms), whereas the third has a large size (5-25 mV) and fast rise time (2-4 ms). This large synaptic input is most likely due to exceptionally large quantal events. The probability of release is rather low, suggesting a stochastic activation of muscle cells. All inputs demonstrated a modest activity-dependent plasticity typical of fast neuromuscular systems. The pre- and postsynaptic properties suggest a rather direct relation between neuronal activity and muscle action. The lack of significant electrical coupling between muscle fibers and the indications for the small size of the motor units suggest that the neuromuscular system of the octopus arm has evolved to ensure a high level of precise localization in the neural control of arm function.

  4. The pKa of the protonated Schiff bases of gecko cone and octopus visual pigments.

    PubMed

    Liang, J; Steinberg, G; Livnah, N; Sheves, M; Ebrey, T G; Tsuda, M

    1994-08-01

    A visual pigment is composed of retinal bound to its apoprotein by a protonated Schiff base linkage. Light isomerizes the chromophore and eventually causes the deprotonation of this Schiff base linkage at the meta II stage of the bleaching cycle. The meta II intermediate of the visual pigment is the active form of the pigment that binds to and activates the G protein transducin, starting the visual cascade. The deprotonation of the Schiff base is mandatory for the formation of meta II intermediate. We studied the proton binding affinity, pKa, of the Schiff base of both octopus rhodopsin and the gecko cone pigment P521 by spectral titration. Several fluorinated retinal analogs have strong electron withdrawing character around the Schiff base region and lower the Schiff base pKa in model compounds. We regenerated octopus and gecko visual pigments with these fluorinated and other retinal analogs. Experiments on these artificial pigments showed that the spectral changes seen upon raising the pH indeed reflected the pKa of the Schiff base and not the denaturation of the pigment or the deprotonation of some other group in the pigment. The Schiff base pKa is 10.4 for octopus rhodopsin and 9.9 for the gecko cone pigment. We also showed that although the removal of Cl- ions causes considerable blue-shift in the gecko cone pigment P521, it affects the Schiff base pKa very little, indicating that the lambda max of visual pigment and its Schiff base pKa are not tightly coupled.

  5. Automated flicker perimetry in glaucoma using Octopus 311: a comparative study with the Humphrey Matrix.

    PubMed

    Matsumoto, Chota; Takada, Sonoko; Okuyama, Sachiko; Arimura, Eiko; Hashimoto, Shigeki; Shimomura, Yoshikazu

    2006-04-01

    We evaluated the clinical usefulness of flicker perimetry in glaucoma and glaucoma suspect patients using the new Octopus 311 automated perimeter. A total of 52 eyes of 52 glaucoma patients, 26 eyes of 26 glaucoma suspect patients and 61 eyes of 61 normal subjects were examined using standard automated perimetry (SAP), flicker perimetry and frequency doubling technology (FDT) perimetry. Flicker perimetry was performed using the Octopus 311 and its remote software package. Suprathreshold four-zone probability strategy was used to classify the critical fusion frequency probability level. The classified levels were set at 5% and 1% of probability of normality and 5 Hz. Frequency doubling technology perimetry was performed using 24-2-5, 24-2-1, N-30-5, N-30-1 screening programs using Humphrey Matrix perimetry. Standard automated perimetry was performed using the Humphrey field analyser program 24-2 full threshold. Optical coherence tomography using Stratus OCT was used for evaluating the retinal nerve fibre layer thickness in all glaucoma and glaucoma suspect patients. Receiver operating characteristic (ROC) curves were calculated. In the early stage of glaucoma, the areas under the ROC curve (AUCs) were 0.96 in flicker and 0.90 in Matrix perimetry. In the moderate and advanced stages of glaucoma, the AUCs were almost 1.0 in all tests. In glaucoma suspect patients, the AUC of the 5% probability level in flicker was significantly higher than in Matrix perimetry. The four-zone probability strategy using the Octopus 311 is a useful method for evaluating the flicker field in early glaucoma and glaucoma suspect patients.

  6. Development of Visual Field Screening Procedures: A Case Study of the Octopus Perimeter

    PubMed Central

    Turpin, Andrew; Myers, Jonathan S.; McKendrick, Allison M.

    2016-01-01

    Purpose We develop a methodology for designing perimetric screening procedures, using Octopus perimeters as a case study. Methods The process has three stages: analytically determining specificity and number of presentations required for different multisampling suprathreshold schemes at a single location of the visual field, ranking visual field locations by their positive predictive value (PPV) for glaucoma, and determining a pass/fail criteria for the test. For the case study the Octopus G-program visual field test pattern is used, and a dataset of 385 glaucoma and 86 normal patients. Results Using a 1-of-3 sampling strategy at a level equal to the 95 percentile of normal observers gave the most robust specificity under the influences of false-negative responses using an average of 1.5 presentations per location. The PPV analysis gave 19 locations that completely classified our glaucomatous data. A further 9 points were added to screen for nonglaucomatous loss. The final stage found that insisting that 3 locations are missed for the screening to fail gave a simulated specificity and sensitivity of approximately 95% for unreliable responders. Conclusions Our method gives a principled approach to choosing between the many parameters of a visual field screening procedure. We have developed a procedure for the Octopus that should terminate in less than 1 minute for normal observers with high specificity and sensitivity to glaucoma. Translational Relevance Visual field screening is used in community settings and eye care practice. This study provides a principled approach to the development of such screening procedures and details a new procedure. PMID:27190698

  7. Microsatellite marker isolation and development for the giant Pacific Octopus (Enteroctopus dofleini)

    USGS Publications Warehouse

    Toussaint, Rebecca K.; Sage, G. Kevin; Talbot, Sandra L.; Scheel, David

    2012-01-01

    We isolated and developed 18 novel microsatellite markers for the giant Pacific octopus (Enteroctopus dofleini) and examined them for 31 individuals from Prince William Sound (PWS), Alaska. These loci displayed moderate levels of allelic diversity (averaging 11 alleles per locus) and heterozygosity (averaging 65%). Seven loci deviated from Hardy–Weinberg Equilibrium (HWE) due to heterozygote deficiency for the PWS population, although deviations were not observed for all these loci in other populations, suggesting the PWS population is not in mutation-drift equilibrium. These novel microsatellite loci yielded sufficient genetic diversity for potential use in population genetics, individual identification, and parentage studies.

  8. Indole Alkaloids from the Sea Anemone Heteractis aurora and Homarine from Octopus cyanea.

    PubMed

    Shaker, Kamel H; Göhl, Matthias; Müller, Tobias; Seifert, Karlheinz

    2015-11-01

    The two new indole alkaloids 2-amino-1,5-dihydro-5-(1H-indol-3-ylmethyl)-4H-imidazol-4-one (1), 2-amino-5-[(6-bromo-1H-indol-3-yl)methyl]-3,5-dihydro-3-methyl-4H-imidazol-4-one (2), and auramine (3) have been isolated from the sea anemone Heteractis aurora. Both indole alkaloids were synthesized for the confirmation of the structures. Homarine (4), along with uracil (5), hypoxanthine (6), and inosine (7) have been obtained from Octopus cyanea.

  9. Stereotypical reaching movements of the octopus involve both bend propagation and arm elongation.

    PubMed

    Hanassy, S; Botvinnik, A; Flash, T; Hochner, B

    2015-05-13

    The bend propagation involved in the stereotypical reaching movement of the octopus arm has been extensively studied. While these studies have analyzed the kinematics of bend propagation along the arm during its extension, possible length changes have been ignored. Here, the elongation profiles of the reaching movements of Octopus vulgaris were assessed using three-dimensional reconstructions. The analysis revealed that, in addition to bend propagation, arm extension movements involve elongation of the proximal part of the arm, i.e., the section from the base of the arm to the propagating bend. The elongations are quite substantial and highly variable, ranging from an average strain along the arm of -0.12 (i.e. shortening) up to 1.8 at the end of the movement (0.57 ± 0.41, n = 64 movements, four animals). Less variability was discovered in an additional set of experiments on reaching movements (0.64 ± 0.28, n = 30 movements, two animals), where target and octopus positions were kept more stationary. Visual observation and subsequent kinematic analysis suggest that the reaching movements can be broadly segregated into two groups. The first group involves bend propagation beginning at the base of the arm and propagating towards the arm tip. In the second, the bend is formed or present more distally and reaching is achieved mainly by elongation and straightening of the segment proximal to the bend. Only in the second type of movements is elongation significantly positively correlated with the distance of the bend from the target. We suggest that reaching towards a target is generated by a combination of both propagation of a bend along the arm and arm elongation. These two motor primitives may be combined to create a broad spectrum of reaching movements. The dynamical model, which recapitulates the biomechanics of the octopus muscular hydrostatic arm, suggests that achieving the observed elongation requires an extremely low ratio of longitudinal to transverse muscle

  10. A multilevel approach to examining cephalopod growth using Octopus pallidus as a model.

    PubMed

    Semmens, Jayson; Doubleday, Zoë; Hoyle, Kate; Pecl, Gretta

    2011-08-15

    Many aspects of octopus growth dynamics are poorly understood, particularly in relation to sub-adult or adult growth, muscle fibre dynamics and repro-somatic investment. The growth of 5 month old Octopus pallidus cultured in the laboratory was investigated under three temperature regimes over a 12 week period: seasonally increasing temperatures (14-18°C); seasonally decreasing temperatures (18-14°C); and a constant temperature mid-way between seasonal peaks (16°C). Differences in somatic growth at the whole-animal level, muscle tissue structure and rate of gonad development were investigated. Continuous exponential growth was observed, both at a group and at an individual level, and there was no detectable effect of temperature on whole-animal growth rate. Juvenile growth rate (from 1 to 156 days) was also monitored prior to the controlled experiment; exponential growth was observed, but at a significantly faster rate than in the older experimental animals, suggesting that O. pallidus exhibit a double-exponential two-phase growth pattern. There was considerable variability in size-at-age even between individuals growing under identical thermal regimes. Animals exposed to seasonally decreasing temperatures exhibited a higher rate of gonad development compared with animals exposed to increasing temperatures; however, this did not coincide with a detectable decline in somatic growth rate or mantle condition. The ongoing production of new mitochondria-poor and mitochondria-rich muscle fibres (hyperplasia) was observed, indicated by a decreased or stable mean muscle fibre diameter concurrent with an increase in whole-body size. Animals from both seasonal temperature regimes demonstrated higher rates of new mitochondria-rich fibre generation relative to those from the constant temperature regime, but this difference was not reflected in a difference in growth rate at the whole-body level. This is the first study to record ongoing hyperplasia in the muscle tissue of an

  11. The complete mitochondrial genome of Octopus conispadiceus (Sasaki, 1917) (Cephalopoda: Octopodidae).

    PubMed

    Ma, Yuanyuan; Zheng, Xiaodong; Cheng, Rubin; Li, Qi

    2016-01-01

    In this paper, we determined the complete mitochondrial genome of Octopus conispadiceus (Cephalopoda: Octopodidae). The whole mitogenome of O. conispadiceus is 16,027 basepairs (bp) in length with a base composition of 41.4% A, 34.8% T, 16.1% C, 7.7% G and contains 13 protein-coding genes, 2 ribosomal RNA genes, 22 transfer RNA genes, and a major non-coding region (MNR). The gene arrangements of O. conispadiceus showed remarkable similarity to that of O. vulgaris, Amphioctopus fangsiao, Cistopus chinensis and C. taiwanicus.

  12. Observations on associated histopathology with Aggregata octopiana infection (Protista: Apicomplexa) in Octopus vulgaris.

    PubMed

    Gestal, C; Abollo, E; Pascual, S

    2002-06-21

    Gamogony and sporogony of Aggregata octopiana were commonly observed during histological examination of the digestive tract of wild Octopus vulgaris from Ria de Vigo (NW Spain). A. octopiana infected noncuticularized caecum and intestine, and cuticularized oesophagus and crop. Infection was also observed in the gills and in covering mesenterium, mainly of the digestive gland and gonad. Histological and ultrastructural lesions associated with A. octopiana included host cell hypertrophy with nuclear displacement, inflammation, phagocytosis, ulceration and destruction of organ architecture. The possible existence of a malabsorption syndrome in the host is deduced.

  13. Experimental infection of octopus vulgaris (Cuvier, 1797) with Photobacterium damsela subsp. piscicida. Immunohistochemical tracking of antigen and tissue responses.

    PubMed

    Bakopoulos, Vasileios; White, Daniella; Valsamidis, Michail-Aggelos; Vasilaki, Feli

    2017-01-17

    Adult common octopus individuals were intramuscularly infected with Photobacterium damsela subsp. piscicida in order to investigate if this species is sensitive to this common and important fish pathogen. The fate of the bacterial antigens and the tissue responses of Octopus vulgaris were studied employing immunohistochemical techniques. Strong reaction at the site of injection was evident from day 2 post-infection that continued until day 14. Great numbers of hemocytes that were attracted at the site of infection were involved in phagocytosis of bacteria. Very early in the infection, a transition of cells to fibroblasts and an effort to isolate the infection was observed. During the course of the study, very large necrotic cells were seen at the site of infection, whereas during the later stages hemocytes with phagocytosed bacteria were observed in well-defined pockets inside the muscle tissue. None of the internal organs tested for the presence of the bacterium were positive with the exception of the digestive gland where antigen staining was observed which was not associated with hemocyte infiltration. The high doses of bacterial cells used in this experimental infection and the lack of disease signs from Octopus vulgaris suggest that, under normal conditions, octopus is resistant to Photobacterium damsela subsp. piscicida.

  14. Perfused Gills Reveal Fundamental Principles of pH Regulation and Ammonia Homeostasis in the Cephalopod Octopus vulgaris

    PubMed Central

    Hu, Marian Y.; Sung, Po-Hsuan; Guh, Ying-Jey; Lee, Jay-Ron; Hwang, Pung-Pung; Weihrauch, Dirk

    2017-01-01

    In contrast to terrestrial animals most aquatic species can be characterized by relatively higher blood NH4+ concentrations despite its potential toxicity to the central nervous system. Although many aquatic species excrete NH4+ via specialized epithelia little information is available regarding the mechanistic basis for NH3/NH4+ homeostasis in molluscs. Using perfused gills of Octopus vulgaris we studied acid-base regulation and ammonia excretion pathways in this cephalopod species. The octopus gill is capable of regulating ammonia (NH3/NH4+) homeostasis by the accumulation of ammonia at low blood levels (<260 μM) and secretion at blood ammonia concentrations exceeding in vivo levels of 300 μM. NH4+ transport is sensitive to the adenylyl cyclase inhibitor KH7 indicating that this process is mediated through cAMP-dependent pathways. The perfused octopus gill has substantial pH regulatory abilities during an acidosis, accompanied by an increased secretion of NH4+. Immunohistochemical and qPCR analyses revealed tissue specific expression and localization of Na+/K+-ATPase, V-type H+-ATPase, Na+/H+-exchanger 3, and Rhesus protein in the gill. Using the octopus gill as a molluscan model, our results highlight the coupling of acid-base regulation and nitrogen excretion, which may represent a conserved pH regulatory mechanism across many marine taxa. PMID:28373845

  15. Octopus gonadotrophin-releasing hormone: a multifunctional peptide in the endocrine and nervous systems of the cephalopod.

    PubMed

    Minakata, H; Shigeno, S; Kano, N; Haraguchi, S; Osugi, T; Tsutsui, K

    2009-03-01

    The optic gland, which is analogous to the anterior pituitary in the context of gonadal maturation, is found on the upper posterior edge of the optic tract of the octopus Octopus vulgaris. In mature octopus, the optic glands enlarge and secrete a gonadotrophic hormone. A peptide with structural features similar to that of vertebrate gonadotrophin-releasing hormone (GnRH) was isolated from the brain of octopus and was named oct-GnRH. Oct-GnRH showed luteinising hormone-releasing activity in the anterior pituitary cells of the Japanese quail Coturnix coturnix. Oct-GnRH immunoreactive signals were observed in the glandular cells of the mature optic gland. Oct-GnRH stimulated the synthesis and release of sex steroids from the ovary and testis, and elicited contractions of the oviduct. Oct-GnRH receptor was expressed in the gonads and accessory organs, such as the oviduct and oviducal gland. These results suggest that oct-GnRH induces the gonadal maturation and oviposition by regulating sex steroidogenesis and a series of egg-laying behaviours via the oct-GnRH receptor. The distribution and expression of oct-GnRH in the central and peripheral nervous systems suggest that oct-GnRH acts as a multifunctional modulatory factor in feeding, memory processing, sensory, movement and autonomic functions.

  16. A soft body as a reservoir: case studies in a dynamic model of octopus-inspired soft robotic arm

    PubMed Central

    Nakajima, Kohei; Hauser, Helmut; Kang, Rongjie; Guglielmino, Emanuele; Caldwell, Darwin G.; Pfeifer, Rolf

    2013-01-01

    The behaviors of the animals or embodied agents are characterized by the dynamic coupling between the brain, the body, and the environment. This implies that control, which is conventionally thought to be handled by the brain or a controller, can partially be outsourced to the physical body and the interaction with the environment. This idea has been demonstrated in a number of recently constructed robots, in particular from the field of “soft robotics”. Soft robots are made of a soft material introducing high-dimensionality, non-linearity, and elasticity, which often makes the robots difficult to control. Biological systems such as the octopus are mastering their complex bodies in highly sophisticated manners by capitalizing on their body dynamics. We will demonstrate that the structure of the octopus arm cannot only be exploited for generating behavior but also, in a sense, as a computational resource. By using a soft robotic arm inspired by the octopus we show in a number of experiments how control is partially incorporated into the physical arm's dynamics and how the arm's dynamics can be exploited to approximate non-linear dynamical systems and embed non-linear limit cycles. Future application scenarios as well as the implications of the results for the octopus biology are also discussed. PMID:23847526

  17. A soft body as a reservoir: case studies in a dynamic model of octopus-inspired soft robotic arm.

    PubMed

    Nakajima, Kohei; Hauser, Helmut; Kang, Rongjie; Guglielmino, Emanuele; Caldwell, Darwin G; Pfeifer, Rolf

    2013-01-01

    The behaviors of the animals or embodied agents are characterized by the dynamic coupling between the brain, the body, and the environment. This implies that control, which is conventionally thought to be handled by the brain or a controller, can partially be outsourced to the physical body and the interaction with the environment. This idea has been demonstrated in a number of recently constructed robots, in particular from the field of "soft robotics". Soft robots are made of a soft material introducing high-dimensionality, non-linearity, and elasticity, which often makes the robots difficult to control. Biological systems such as the octopus are mastering their complex bodies in highly sophisticated manners by capitalizing on their body dynamics. We will demonstrate that the structure of the octopus arm cannot only be exploited for generating behavior but also, in a sense, as a computational resource. By using a soft robotic arm inspired by the octopus we show in a number of experiments how control is partially incorporated into the physical arm's dynamics and how the arm's dynamics can be exploited to approximate non-linear dynamical systems and embed non-linear limit cycles. Future application scenarios as well as the implications of the results for the octopus biology are also discussed.

  18. Comprehensive screening of octopus amphiphiles as DNA activators in lipid bilayers: implications on transport, sensing and cellular uptake.

    PubMed

    Montenegro, Javier; Fin, Andrea; Matile, Stefan

    2011-04-21

    Dynamic octopus amphiphiles contain one charged "head," here a guanidinium cation, together several hydrophobic "tails" (or "tentacles") that can be attached and exchanged in situ by reversible hydrazone formation. Quite surprisingly, their ability to activate DNA as transporters in lipid bilayer membranes was found to increase with the number of tails (up to four) as well as with their length (up to eight carbons). Both encouraged and puzzled by these results, we decided that a comprehensive screening of octopus amphiphiles with regard to number (from one to six) and length (from three to eighteen carbons) of their tails would be appropriate at this point. For this purpose, we here report the synthesis of cationic hexahydrazide peptide dendrons together with that of aldehydes with long, saturated, unsaturated and branched hydrophobic tails. Comprehensive screening of the completed collection of tails and heads reveals that the ability of octopus amphiphiles to activate DNA transporters shifts with increasing number of tails to decreasing length of the tails. Moreover, cis-alkenyl and branched alkyl tails are more active than their linear analogs, branched aromatic tails are best. These overall very meaningful trends for octopus amphiphiles will be of importance for sensing applications and fragrant cellular uptake.

  19. Perfused Gills Reveal Fundamental Principles of pH Regulation and Ammonia Homeostasis in the Cephalopod Octopus vulgaris.

    PubMed

    Hu, Marian Y; Sung, Po-Hsuan; Guh, Ying-Jey; Lee, Jay-Ron; Hwang, Pung-Pung; Weihrauch, Dirk; Tseng, Yung-Che

    2017-01-01

    In contrast to terrestrial animals most aquatic species can be characterized by relatively higher blood [Formula: see text] concentrations despite its potential toxicity to the central nervous system. Although many aquatic species excrete [Formula: see text] via specialized epithelia little information is available regarding the mechanistic basis for NH3/[Formula: see text] homeostasis in molluscs. Using perfused gills of Octopus vulgaris we studied acid-base regulation and ammonia excretion pathways in this cephalopod species. The octopus gill is capable of regulating ammonia (NH3/[Formula: see text]) homeostasis by the accumulation of ammonia at low blood levels (<260 μM) and secretion at blood ammonia concentrations exceeding in vivo levels of 300 μM. [Formula: see text] transport is sensitive to the adenylyl cyclase inhibitor KH7 indicating that this process is mediated through cAMP-dependent pathways. The perfused octopus gill has substantial pH regulatory abilities during an acidosis, accompanied by an increased secretion of [Formula: see text]. Immunohistochemical and qPCR analyses revealed tissue specific expression and localization of Na(+)/K(+)-ATPase, V-type H(+)-ATPase, Na(+)/H(+)-exchanger 3, and Rhesus protein in the gill. Using the octopus gill as a molluscan model, our results highlight the coupling of acid-base regulation and nitrogen excretion, which may represent a conserved pH regulatory mechanism across many marine taxa.

  20. Tools and methods for experimental in-vivo measurement and biomechanical characterization of an Octopus vulgaris arm.

    PubMed

    Margheri, Laura; Mazzolai, Barbara; Cianchetti, Matteo; Dario, Paolo; Laschi, Cecilia

    2009-01-01

    This work illustrates new tools and methods for an in vivo and direct, but non-invasive, measurement of an octopus arm mechanical properties. The active elongation (longitudinal stretch) and the pulling force capability are measured on a specimen of Octopus vulgaris in order to quantitatively characterize the parameters describing the arm mechanics, for biomimetic design purposes. The novel approach consists of observing and measuring a living octopus with minimally invasive methods, which allow the animal to move with its complete ability. All tools are conceived in order to create a collaborative interaction with the animal for the acquisition of active measures. The data analysis is executed taking into account the presence of an intrinsic error due to the mobility of the subject and the aquatic environment. Using a system of two synchronized high-speed high-resolution cameras and purpose-made instruments, the maximum elongation of an arm and its rest length (when all muscles fibres are relaxed during propulsion movement) are measured and compared to define the longitudinal stretch, with the impressive average result of 194%. With a similar setup integrated with a force sensor, the pulling force capability is measured as a function of grasp point position along the arm. The measured parameters are used as real specifications for the design of an octopus-like arm with a biomimetic approach.

  1. Octopus visual system: a functional MRI model for detecting neuronal electric currents without a BOLD confound

    PubMed Central

    Jiang, Xia; Lu, Hanbing; Shigeno, Shuichi; Tan, Li-Hai; Yang, Yihong; Ragsdale, Clifton W.; Gao, Jia-Hong

    2014-01-01

    Purpose Despite the efforts that have been devoted to detecting the transient magnetic fields generated by neuronal firing, the conclusion that a functionally relevant signal can be measured with magnetic resonance imaging (MRI) is still controversial. For human studies of neuronal current MRI (nc-MRI), the blood-oxygen-level-dependent (BOLD) effect remains an irresolvable confound. For tissue studies where hemoglobin is removed, natural sensory stimulation is not possible. This study investigates the feasibility of detecting a physiologically induced nc-MRI signal in vivo in a BOLD-free environment. Methods The cephalopod mollusc Octopus bimaculoides has vertebrate-like eyes, large optic lobes (OLs) and blood that does not contain hemoglobin. Visually evoked potentials were measured in the octopus retina and OL by electroretinogram and local field potential. nc-MRI scans were conducted at 9.4 Tesla to capture these activities. Results Electrophysiological recording detected strong responses in the retina and OL in vivo; however, nc-MRI failed to demonstrate any statistically significant signal change with a detection threshold of 0.2° for phase and 0.2% for magnitude. Experiments in a dissected eye-OL preparation yielded similar results. Conclusion These findings in a large hemoglobin-free nervous system suggest that sensory evoked neuronal magnetic fields are too weak for direct detection with current MRI technology. PMID:24301336

  2. Self-Assembly of Octopus Nanoparticles into Pre-Programmed Finite Clusters

    NASA Astrophysics Data System (ADS)

    Halverson, Jonathan; Tkachenko, Alexei

    2012-02-01

    The precise control of the spatial arrangement of nanoparticles (NP) is often required to take full advantage of their novel optical and electronic properties. NPs have been shown to self-assemble into crystalline structures using either patchy surface regions or complementary DNA strands to direct the assembly. Due to a lack of specificity of the interactions these methods lead to only a limited number of structures. An emerging approach is to bind ssDNA at specific sites on the particle surface making so-called octopus NPs. Using octopus NPs we investigate the inverse problem of the self-assembly of finite clusters. That is, for a given target cluster (e.g., arranging the NPs on the vertices of a dodecahedron) what are the minimum number of complementary DNA strands needed for the robust self-assembly of the cluster from an initially homogeneous NP solution? Based on the results of Brownian dynamics simulations we have compiled a set of design rules for various target clusters including cubes, pyramids, dodecahedrons and truncated icosahedrons. Our approach leads to control over the kinetic pathway and has demonstrated nearly perfect yield of the target.

  3. Transcriptional and Biochemical Effects of Cadmium and Manganese on the Defense System of Octopus vulgaris Paralarvae

    PubMed Central

    Salamone, Monica; Mazzola, Salvatore; Cuttitta, Angela

    2015-01-01

    Due to anthropogenic activities the relative concentrations of cadmium and manganese have increased in the marine environment. Cephalopods are able to accumulate such metals and, as inhabitant of coastal waters, Octopus vulgaris is continuously exposed to anthropogenic activities. Since no study is available on the effects of heavy metals at molecular level in developing octopuses, herein we exposed 1-day-old paralarvae for 24 h to 10, 100, and 1000 μg/L of CdCl2 or MnCl2. Cd exerted a concentration-dependent inhibition of survival and a reduction in growth rate was shown while Mn exposure did not affect the survival rate even at the highest concentrations. Gene expression profiles of hsp70, sod, cat, and gst genes were analyzed by quantitative real-time PCR and defined patterns of transcription were observed. Moreover posttranscriptional analyses were also performed suggesting the impairment of metabolic functions, under strong oxidative conditions (as occurred in paralarvae exposed to Cd) or the complete detoxification events (as occurred in paralarvae exposed to Mn). PMID:25705660

  4. [Microbiological analysis of red octopus in fishing ports of Campeche, Mexico].

    PubMed

    Estrella-Gómez, Neyi; Escalante-Réndiz, Diana; González-Burgos, Araceli; Sosa-Cordero, Delta; Rojas-Herrera, Rafael

    2016-08-01

    In this work we studied the microbiological quality of the red octopus given its important economic and social impact on the region South-Southeast of Mexico. Samples were taken in different areas of capture of the species and analyzed with biochemical tests described in the Mexican official standards, identifying strains belonging to the genus Vibrio, Salmonella and faecal coliforms, and E. coli O157: H7. We used the BAx System for the identification of microorganisms through their bacterial DNA. The results obtained in biochemical and molecular methods were confirmed. Bland-Altman statistical method pointed out that both techniques can be used interchangeably. McNemar test showed that both methods have the same efficacy for the identification of pathogens (value X2=0.5 ρ=0.4795). The microbiological quality of the octopus in the South-Southeast region of Mexico is deficient due to the presence of pathogenic intestinal flora that might represent an epidemiological risk. The indexes established by the regulations suggest the need to apply effective and rapid identification technologies, such as the BAx System.This alternative method of analysis can contribute to the implementation of effective strategies that allow compliance with the minimal sanitary specifications during the processing of fishing products, thus strengthening the control systems to decrease the risks of epidemiological outbreaks in the region.

  5. How does the blue-ringed octopus (Hapalochlaena lunulata) flash its blue rings?

    PubMed

    Mäthger, Lydia M; Bell, George R R; Kuzirian, Alan M; Allen, Justine J; Hanlon, Roger T

    2012-11-01

    The blue-ringed octopus (Hapalochlaena lunulata), one of the world's most venomous animals, has long captivated and endangered a large audience: children playing at the beach, divers turning over rocks, and biologists researching neurotoxins. These small animals spend much of their time in hiding, showing effective camouflage patterns. When disturbed, the octopus will flash around 60 iridescent blue rings and, when strongly harassed, bite and deliver a neurotoxin that can kill a human. Here, we describe the flashing mechanism and optical properties of these rings. The rings contain physiologically inert multilayer reflectors, arranged to reflect blue-green light in a broad viewing direction. Dark pigmented chromatophores are found beneath and around each ring to enhance contrast. No chromatophores are above the ring; this is unusual for cephalopods, which typically use chromatophores to cover or spectrally modify iridescence. The fast flashes are achieved using muscles under direct neural control. The ring is hidden by contraction of muscles above the iridophores; relaxation of these muscles and contraction of muscles outside the ring expose the iridescence. This mechanism of producing iridescent signals has not previously been reported in cephalopods and we suggest that it is an exceptionally effective way to create a fast and conspicuous warning display.

  6. Octopus lipid and vitamin E composition: interspecies, interorigin, and nutritional variability.

    PubMed

    Torrinha, Alvaro; Cruz, Rebeca; Gomes, Filipa; Mendes, Eulália; Casal, Susana; Morais, Simone

    2014-08-20

    Octopus vulgaris, Octopus maya, and Eledone cirrhosa from distinct marine environments [Northeast Atlantic (NEA), Northwest Atlantic (NWA), Eastern Central Atlantic, Western Central Atlantic (WCA), Pacific Ocean, and Mediterranean Sea] were characterized regarding their lipid and vitamin E composition. These species are those commercially more relevant worldwide. Significant interspecies and interorigin differences were observed. Unsaturated fatty acids account for more than 65% of total fatty acids, mostly ω-3 PUFA due to docosahexaenoic (18.4-29.3%) and eicosapentanoic acid (11.4-23.9%) contributions. The highest ω-3 PUFA amounts and ω-3/ω-6 ratios were quantified in the heaviest specimens, O. vulgaris from NWA, with high market price, and simultaneously in the lowest graded samples, E. cirrhosa from NEA, of reduced dimensions. Although having the highest cholesterol contents, E. cirrhosa from NEA and O. maya from WCA have also higher protective fatty acid indexes. Chemometric discrimination allowed clustering the selected species and several origins based on lipid and vitamin E profiles.

  7. Transcriptional and biochemical effects of cadmium and manganese on the defense system of Octopus vulgaris paralarvae.

    PubMed

    Nicosia, Aldo; Salamone, Monica; Mazzola, Salvatore; Cuttitta, Angela

    2015-01-01

    Due to anthropogenic activities the relative concentrations of cadmium and manganese have increased in the marine environment. Cephalopods are able to accumulate such metals and, as inhabitant of coastal waters, Octopus vulgaris is continuously exposed to anthropogenic activities. Since no study is available on the effects of heavy metals at molecular level in developing octopuses, herein we exposed 1-day-old paralarvae for 24 h to 10, 100, and 1000 μg/L of CdCl2 or MnCl2. Cd exerted a concentration-dependent inhibition of survival and a reduction in growth rate was shown while Mn exposure did not affect the survival rate even at the highest concentrations. Gene expression profiles of hsp70, sod, cat, and gst genes were analyzed by quantitative real-time PCR and defined patterns of transcription were observed. Moreover posttranscriptional analyses were also performed suggesting the impairment of metabolic functions, under strong oxidative conditions (as occurred in paralarvae exposed to Cd) or the complete detoxification events (as occurred in paralarvae exposed to Mn).

  8. N-methyl-D-aspartate receptor-like immunoreactivity in the brain of Sepia and Octopus.

    PubMed

    Di Cosmo, Anna; Paolucci, Marina; Di Cristo, Carlo

    2004-09-13

    Ionotropic glutamate receptors have been subdivided into N-methyl-D-aspartate (NMDA) and AMPA/kainate classes. NMDA receptor subunit 2A and 2B immunoreactivity is shown to be present in specific regions of the central nervous system (CNS) of the cephalopod molluscs Sepia officinalis and Octopus vulgaris. An antibody that recognizes both mammalian NMDAR2A and NMDAR2B subunits equally was used. SDS-PAGE/Western blot analysis performed on membrane proteins revealed an immunoreactive band at 170 kDa for both species. Immunoreactive bands from both Octopus and Sepia brains disappeared when the antibody was preabsorbed with membrane proteins from rat hippocampus or from their own brains. The same antibody was then used for immunohistochemical staining of serial sections of the CNS to reveal localized specific staining of cell bodies and fibers in several lobes of the brain. Staining was found in lower motor centers, in some higher motor centers, in learning centers, and in the optic lobes. Immunopositivity was also found in the areas of brain that control the activity of the optic gland, a gonadotropic endocrine gland. These findings suggest that glutamate, via NMDA receptors, may be involved as a signaling molecule in motor, learning, visual, and olfactory systems in the cephalopod brain.

  9. Role of FMRFamide in the reproduction of Octopus vulgaris: molecular analysis and effect on visual input.

    PubMed

    Di Cristo, Carlo; Delli Bovi, Pasquale; Di Cosmo, Anna

    2003-10-01

    As a part of continuous research on the neurobiology of the cephalopods in general, and the neuroendocrine control of reproduction in Octopus vulgaris in particular, the presence, the molecular analysis and the effect of FMRFamide on the screening-pigment migration in the visual system have been analysed. FMRFamide immunoreactive fibres are present in the outer plexiform layer of the retina as well as in the plexiform zone of the deep retina. These fibres presumably come from optic and olfactory lobes. We isolated an incomplete Octopus FMRFamide cDNA which encodes an amino terminal truncated precursor containing several FMRFamide-related peptides (FaRPs) showing a high degree of identity with the FaRPs encoded in the precursor of Sepia officinalis, except for the presence of an Rpamide related peptide, present only in cnidarians. Finally, stimulation of isolated retina demonstrated that the effect of this tetrapeptide, coupled with dopamine, is the induction of an extreme adaptation of the retina to the light condition. This situation de facto inhibits sexual maturation. Our results on the effect of FMRFamide on the retina confirm the suggested hypothesis that this peptide plays an inhibitory role on the activity of optic gland.

  10. The presence of APGWamide in Octopus vulgaris: a possible role in the reproductive behavior.

    PubMed

    Di Cristo, Carlo; Van Minnen, Jan; Di Cosmo, Anna

    2005-01-01

    The concerted action of many neuropeptides has been implicated in the nervous control of specific behaviors in many molluscs. In the present study, the presence of amidated tetrapeptide Ala-Pro-Gly-Trp-NH2 (APGWamide) in those lobes that are involved in the control of reproductive behavior in Octopus vulgaris has been investigated. APGWamide immunoreactivity was mainly confined to the posterior olfactory lobule and in the inferior frontal system. These areas are involved in Octopus in the processing of either chemotactile sense or olfaction. From these lobes, immunoreactive fibers reached other lobes of the central nervous system (CNS) which could be indirectly involved in the reproductive behavior. APGWamide immunoreactivity was also present in the glandular cells of the oviducal gland in the female reproductive system. These results constitute the first detailed immunolocalization of APGWamide in cephalopods and open a new insight into the possible effects that both distant and close chemical stimuli can exert on neuropeptidergic circuitries, which may affect the reproductive behavior of cephalopods.

  11. Octopus vulgaris (Cuvier, 1797) in the Mediterranean Sea: Genetic Diversity and Population Structure

    PubMed Central

    De Luca, Daniele; Catanese, Gaetano; Procaccini, Gabriele; Fiorito, Graziano

    2016-01-01

    The common octopus, Octopus vulgaris Cuvier 1797, is a largely exploited cephalopod species in the Mediterranean Sea and the Atlantic Ocean, as well as along the coasts of Africa, Brazil and Japan, where its taxonomic identity is still debated. The assessment of its genetic structure is a pressing need to correctly manage the resource and to avoid overfishing and collapsing of local stocks. Here we analysed genetic variation and population structure of O. vulgaris using thirteen microsatellite loci in seven sampling localities from the Mediterranean Sea and one from the Atlantic Ocean. We also used a DNA barcoding approach by COI gene fragment to understand the phylogenetic relationships among the specimens here investigated and the ones whose sequences are available in literature. Our results reveal high levels of allelic richness and moderate heterozygosity in all samples investigated, and a pronounced differentiation of the Atlantic and Sicilian specimens. This latter aspect seems to support the isolation of the biota within the Strait of Messina. A certain degree of differentiation was detected among the other geographic samples within the Mediterranean Sea, which is more compatible with an island model than isolation by distance. The occurrence of null alleles affected more genetic diversity indices than population structure estimations. This study provides new insights about the genetic diversity and structure of O. vulgaris in the area of interest, which can be used as guidelines for a fisheries management perspective. PMID:26881847

  12. Inter-cohort growth for three tropical resources: tilapia, octopus and lobster.

    PubMed

    Velázquez-Abunader, Iván; Gómez-Muñoz, Victor Manuel; Salas, Silvia; Ruiz-Velazco, Javier M J

    2015-09-01

    Growth parameters are an important component for the stock assessment of exploited aquatic species. However, it is often difficult to apply direct methods to estimate growth and to analyse the differences between males and females, particularly in tropical areas. The objective of this study was to analyse the inter-cohort growth of three tropical resources and discuss the possible fisheries management implications. A simple method was used to compare individual growth curves obtained from length frequency distribution analysis, illustrated by case studies of three tropical species from different aquatic environments: tilapia (Oreochromis aureus), red octopus (Octopus maya) and the Caribbean spiny lobster (Panulirus argus). The analysis undertaken compared the size distribution of males and females of a given cohort through modal progression analysis. The technique used proved to be useful for highlighting the differences in growth between females and males of a specific cohort. The potential effect of extrinsic and intrinsic factors on the organism's development as reflected in the size distribution of the cohorts is discussed.

  13. Differential proteins of the optic ganglion in octopus vulgaris under methanol stress revealed using proteomics.

    PubMed

    Huang, Lin; Huang, Qing-Yu; Chen, Hai-Bin; Huang, Fu-Sheng; Huang, He-Qing

    2011-10-01

    An analytical approach using the two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) technique separated the proteome from the optic ganglia of Octopus vulgaris (OVOG). Approximately 600 protein spots were detected from the extraction when applying 150 μg protein to a 2D-PAGE gel in the pH range 5.0-8.0. Compared to the control, significant changes of 18 protein spots were observed in OVOG under the stress of native seawater containing 2% methanol for 72 h. Among these spots, we found that eight were down-regulated and ten were up-regulated in the gels, which were further identified using both peptide mass fingerprinting and database searches. Significant proteins such as glyceraldehyde-3-phosphate dehydrogenase, alpha subunit of succinyl-CoA synthetase, alcohol dehydrogenase, and long-chain specific acyl-CoA dehydrogenase were up-regulated proteins, whereas putative ABC transporter was a down -regulated protein. These differential proteins at the level of subcellular localization were further classified using LOCtree software with a hierarchical system of support vector machines. We found that most of the differential proteins in the gel could be identified as mitochondrial proteins, suggesting that these protective or marker proteins might help to prevent methanol poisoning via the mitochondria in the optical ganglia. The results indicated that both beta-tubulin and beta-actin were potential biomarkers as up-regulated proteins for monitoring methanol toxicosis associated with fish foods such as octopus and shark.

  14. Octopus vulgaris (Cuvier, 1797) in the Mediterranean Sea: Genetic Diversity and Population Structure.

    PubMed

    De Luca, Daniele; Catanese, Gaetano; Procaccini, Gabriele; Fiorito, Graziano

    2016-01-01

    The common octopus, Octopus vulgaris Cuvier 1797, is a largely exploited cephalopod species in the Mediterranean Sea and the Atlantic Ocean, as well as along the coasts of Africa, Brazil and Japan, where its taxonomic identity is still debated. The assessment of its genetic structure is a pressing need to correctly manage the resource and to avoid overfishing and collapsing of local stocks. Here we analysed genetic variation and population structure of O. vulgaris using thirteen microsatellite loci in seven sampling localities from the Mediterranean Sea and one from the Atlantic Ocean. We also used a DNA barcoding approach by COI gene fragment to understand the phylogenetic relationships among the specimens here investigated and the ones whose sequences are available in literature. Our results reveal high levels of allelic richness and moderate heterozygosity in all samples investigated, and a pronounced differentiation of the Atlantic and Sicilian specimens. This latter aspect seems to support the isolation of the biota within the Strait of Messina. A certain degree of differentiation was detected among the other geographic samples within the Mediterranean Sea, which is more compatible with an island model than isolation by distance. The occurrence of null alleles affected more genetic diversity indices than population structure estimations. This study provides new insights about the genetic diversity and structure of O. vulgaris in the area of interest, which can be used as guidelines for a fisheries management perspective.

  15. Quantitative elemental imaging of octopus stylets using PIXE and the nuclear microprobe

    NASA Astrophysics Data System (ADS)

    Doubleday, Zoë; Belton, David; Pecl, Gretta; Semmens, Jayson

    2008-01-01

    By utilising targeted microprobe technology, the analysis of elements incorporated within the hard bio-mineralised structures of marine organisms has provided unique insights into the population biology of many species. As hard structures grow, elements from surrounding waters are incorporated effectively providing a natural 'tag' that is often unique to the animal's particular location or habitat. The spatial distribution of elements within octopus stylets was investigated, using the nuclear microprobe, to assess their potential for determining dispersal and population structure in octopus populations. Proton Induced X-ray Emission (PIXE) was conducted using the Dynamic Analysis method and GeoPIXE software package, which produced high resolution, quantitative elemental maps of whole stylet cross-sections. Ten elements were detected within the stylets which were heterogeneously distributed throughout the microstructure. Although Ca decreased towards the section edge, this trend was consistent between individuals and remained homogeneous in the inner region of the stylet, and thus appears a suitable internal standard for future microprobe analyses. Additional analyses used to investigate the general composition of the stylet structure suggested that they are amorphous and largely organic, however, there was some evidence of phosphatic mineralisation. In conclusion, this study indicates that stylets are suitable for targeted elemental analysis, although this is currently limited to the inner hatch region of the microstructure.

  16. Sex identification and mating in the blue-ringed octopus, Hapalochlaena lunulata.

    PubMed

    Cheng; Caldwell

    2000-07-01

    We studied the reproductive behaviour of the blue-ringed octopus, Hapalochlaena lunulata, in the laboratory by examining 15 male-male and nine male-female interactions. The initiation of physical contact was independent of sex, size or residency status, and there were no noticeable changes in behaviour such as sexual displays associated with courtship or aggression prior to contact. Males did not distinguish between females or other males and copulated (defined as the insertion of the hectocotylus into the mantle cavity of another octopus) readily with both. Spermatophores were released in all copulations with females but not with males. The duration of copulation was significantly longer in male-female interactions (median 160.5 min) than in male-male interactions (median 30 s). Although male-male copulations ended passively with the withdrawal of the hectocotylus by the initiating animal, male-female copulations were always terminated by the females following an intense struggle. These studies suggest the inability of male H. lunulata to determine the sexual identity of potential mates prior to the insertion of the hectocotylus and demonstrate the active role of the female during copulation. Copyright 2000 The Association for the Study of Animal Behaviour.

  17. Nerve degeneration and regeneration in the cephalopod mollusc Octopus vulgaris: the case of the pallial nerve

    PubMed Central

    Imperadore, Pamela; Shah, Sameer B.; Makarenkova, Helen P.; Fiorito, Graziano

    2017-01-01

    Regeneration is a process that restores structure and function of tissues damaged by injury or disease. In mammals complete regeneration is often unsuccessful, while most of the low phyla animals can re-grow many parts of their body after amputation. Cephalopod molluscs, and in particular Octopus vulgaris, are well known for their capacity to regenerate their arms and other body parts, including central and peripheral nervous system. To better understand the mechanism of recovery following nerve injury in this species we investigated the process of axon regrowth and nerve regeneration after complete transection of the Octopus pallial nerves. This injury induces scar formation and activates the proliferation of hemocytes which invade the lesion site. Hemocytes appear involved in debris removal and seem to produce factors that foster axon re-growth. Connective tissue is involved in driving regenerating fibers in a single direction, outlining for them a well-defined pathway. Injured axons are able to quickly re-grow thus to restoring structure and function. PMID:28425503

  18. Formation of a fluorous/organic biphasic supramolecular octopus assembly for enhanced porphyrin phosphorescence in air.

    PubMed

    Yang, Chi; Arvapally, Ravi K; Tekarli, Sammer M; Salazar, Gustavo A; Elbjeirami, Oussama; Wang, Xiaoping; Omary, Mohammad A

    2015-04-13

    The trinuclear triangle-shaped system [tris{3,5-bis(heptafluoropropyl)-1,2,4-triazolatosilver(I)}] (1) and the multi-armed square-shaped metalloporphyrin PtOEP or the free porphyrin base H2OEP serve as excellent octopus hosts (OEP=2,3,7,8,12,13,17,18-octaethyl-21H,23H-porphine). Coupling of the fluorous/organic molecular octopi 1 and H2OEP or PtOEP by strong quadrupole-quadrupole and metal-π interactions affords the supramolecular assemblies [1⋅PtOEP] or [1⋅H2OEP] (2 a), which feature nanoscopic cavities surrounding the upper triangular and lower square cores. The fluorous/organic biphasic configuration of [1⋅PtOEP] leads to an increase in the phosphorescence of PtOEP under ambient conditions. Guest molecules can be included in the biphasic double-octopus assembly in three different site-selective modes. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Carbocyanine dye labeling reveals a new motor nucleus in octopus brain.

    PubMed

    Robertson, J D; Schwartz, O M; Lee, P

    1993-02-22

    This work aims at a better understanding of the organization of the brain of Octopus vulgaris, emphasizing the touch and visual learning centers. We injected the carbocyanine dye, DiI, into the cerebrobrachial connectives and, separately, into the brachial nerves of living octopuses. In both experiments, retrogradely transported granules of DiI appeared in motor neurons in the superior buccal, posterior buccal and subvertical lobes and in a hitherto unsuspected motor nucleus of several hundred neurons in the posterior dorsal basal and median basal lobes. In addition we labeled afferent fibers by injecting DiI into the caudal (sensory) division of the cerebrobrachial connective on one side; the label spread throughout the superior buccal, posterior buccal and the lateral and median inferior frontal lobes mainly on the injected side. It extended through the cerebral tract into the subvertical lobe, into the superior frontal lobe through the interfrontal tract, through the posterior buccal commissure into the opposite posterior buccal lobe and into the median inferior frontal lobe. The work suggests a new function for the posterior dorsal and median basal lobes, which are shown for the first time to project through the inferior frontal lobe system into the brachial nerves. In addition it represents the first full report of the successful use of the carbocyanine dyes DiI and DiO for labeling nerve tissue in a live invertebrate animal.

  20. Patterns of motor activity in the isolated nerve cord of the octopus arm.

    PubMed

    Gutfreund, Yoram; Matzner, Henry; Flash, Tamar; Hochner, Binyamin

    2006-12-01

    The extremely flexible octopus arm provides a unique opportunity for studying movement control in a highly redundant motor system. We describe a novel preparation that allows analysis of the peripheral nervous system of the octopus arm and its interaction with the muscular and mechanosensory elements of the arm's intrinsic muscular system. First we examined the synaptic responses in muscle fibers to identify the motor pathways from the axial nerve cord of the arm to the surrounding musculature. We show that the motor axons project to the muscles via nerve roots originating laterally from the arm nerve cord. The motor field of each nerve is limited to the region where the nerve enters the arm musculature. The same roots also carry afferent mechanosensory information from the intrinsic muscle to the axial nerve cord. Next, we characterized the pattern of activity generated in the dorsal roots by electrically stimulating the axial nerve cord. The evoked activity, although far reaching and long lasting, cannot alone account for the arm extension movements generated by similar electrical stimulation. The mismatch between patterns of activity in the isolated cord and in an intact arm may stem from the involvement of mechanosensory feedback in natural arm extension.

  1. Light-/dark-induced changes in rhabdom structure in the retina of Octopus bimaculoides.

    PubMed

    Torres, S C; Camacho, J L; Matsumoto, B; Kuramoto, R T; Robles, L J

    1997-10-01

    We examined rhabdom structure and the distribution of filamentous actin in the photoreceptor outer segments of the retina of Octopus bimaculoides. Animals were dark- or light-adapted, fixed, embedded and sectioned for light and electron microscopy. Statistical analyses were used to compare relative cross-sectional areas of rhabdom microvilli and core cytoplasm within and between the two lighting conditions. Dark-/light-adapted rhabdoms were also prepared for confocal laser scanning microscopy and labeled with fluorescence-tagged phalloidin. Results show differences in the morphology of dark- and light-adapted octopus rhabdoms with the cross-sectional areas of the rhabdoms increasing in dark-adapted retinas and diminishing in the light. Comparisons between the lighting conditions show that an avillar portion of the photoreceptor outer segment membrane, prominent in the light-adapted retina, is recruited to form new rhabdomere microvilli in dark-adapted eyes. Filamentous actin was associated with the avillar membrane in light-adapted retinas, which may indicate that actin and other microvillus core proteins remain linked to the avillar membrane to support rapid microvillus formation in the dark. Photopigment redistributions also occur in light- and dark-adapted retinas, and this study suggests that these changes must be coordinated with the simultaneous breakdown and reformation of the rhabdomere microvilli.

  2. Acute toxicity of crude and dispersed oil to Octopus pallidus (Hoyle, 1885) hatchlings.

    PubMed

    Long, Sara M; Holdway, Douglas A

    2002-06-01

    There is an increasing risk of a major oil spill in Australian waters over the next 20 years but there have been few studies on the impact of oil spills, and subsequent remedial action, on native Australian fauna. Octopus pallidus is a native Australian octopus species found in south-eastern Australia. The aim of the experiment was to investigate the effects of acute exposure to crude and dispersed crude oil and 4-chlorophenol (a reference toxicant) on recently hatched O. pallidus by calculating the 48-h LC50. Water-accommodated fraction (WAF) of Bass Strait crude oil was prepared using a ratio of one part crude oil to nine parts filtered seawater and mixing for 23 h. Dispersed-WAF was prepared using a ratio of one part Corexit 9527 to 50 parts crude oil and an oil to water ratio of one to nine and mixing for 23 h. Mean (SE) 48 h LC50 values were 0.39 (0.04), 1.83 (0.64) and 0.89 (0.08) ppm for WAF, dispersed-WAF and 4 chlorophenol, respectively. These results demonstrate that addition of the chemical dispersant Corexit 9527 to WAF does not increase the toxicity of WAF to O. pallidus hatchlings.

  3. High concentrations of dimethylamine and methylamine in squid and octopus and their implications in tumour aetiology.

    PubMed

    Lin, J K; Lee, Y J; Chang, H W

    1983-04-01

    The levels of the common secondary amines in various squid, in octopus and in 17 other seafoods were determined by HPLC. Ammonia and dimethylamine were found in all of the seafoods tested and some of them also contained methylamine and/or ethylamine. Particularly high levels of dimethylamine (946-2043 ppm) and methylamine (38-255 ppm) were detected in various species of squid and in the octopus. Reaction of nitrite in acidic medium with aqueous extract of squid yielded appreciable amounts of N-nitrosodimethylamine. The optimum pH for this reaction was around 2.4. Dimethylamine in dried squid tissues was readily extracted with water or 1% sodium carbonate solution. Heat treatment of dried squid at 200 degrees C was found to increase its amine content dramatically. It appeared that pyrolytic decarboxylation of some amino acids might cause this increase. Squid is a popular seafood in Japan and other oriental countries. The high incidence of stomach cancer in Japan and China is thought by epidemiologists to be associated with traditional Japanese and Chinese diets. Our present finding that squid and other seafoods contain unusually high levels of dimethylamine and other amines adds to the evidence that dietary factors may have an important role in the aetiology of stomach cancer and other gastro-intestinal tumours.

  4. Progesterone receptor in the reproductive system of the female of Octopus vulgaris: characterization and immunolocalization.

    PubMed

    Di Cosmo, A; Paolucci, M; Di Cristo, C; Botte, V; Ciarcia, G

    1998-08-01

    In this study for the first time we have characterized a progesterone receptor in the reproductive system of the female of Octopus vulgaris. Scatchard analysis revealed that one binding component with high affinity and low capacity for the ligand was present only in the nuclear extract. Competition experiments showed that the progesterone receptor was strictly specific for progesterone. DNA-cellulose binding and DEAE-Sephacel both confirmed the presence of one 3H-progesterone binding component which eluted at a salt concentration of 0.14 +/- 0.05 M NaCl and 0.15 +/- 0.05 M NaCl respectively. By using monoclonal antibodies against chicken progesterone receptor (subunits A and B), we have localized on Western Blot one band of about 70 kDa. Immunoreactivity for progesterone binding molecules has been localized in the nuclei of the follicle cells of the ovary, of the proximal portion of the oviduct and of the outer region of the nidimental gland. These data, taken together, provide evidence that in Octopus vulgaris the progesterone receptor has biochemical and immunohistochemical characteristics resembling those of progesterone receptor in vertebrates.

  5. The argonaut shell: gas-mediated buoyancy control in a pelagic octopus.

    PubMed

    Finn, Julian K; Norman, Mark D

    2010-10-07

    Argonauts (Cephalopoda: Argonautidae) are a group of rarely encountered open-ocean pelagic octopuses with benthic ancestry. Female argonauts inhabit a brittle 'paper nautilus' shell, the role of which has puzzled naturalists for millennia. The primary role attributed to the shell has been as a receptacle for egg deposition and brooding. Our observations of wild argonauts have revealed that the thin calcareous shell also functions as a hydrostatic structure, employed by the female argonaut to precisely control buoyancy at varying depths. Female argonauts use the shell to 'gulp' a measured volume of air at the sea surface, seal off the captured gas using flanged arms and forcefully dive to a depth where the compressed gas buoyancy counteracts body weight. This process allows the female argonaut to attain neutral buoyancy at depth and potentially adjust buoyancy to counter the increased (and significant) weight of eggs during reproductive periods. Evolution of this air-capture strategy enables this negatively buoyant octopus to survive free of the sea floor. This major shift in life mode from benthic to pelagic shows strong evolutionary parallels with the origins of all cephalopods, which attained gas-mediated buoyancy via the closed-chambered shells of the true nautiluses and their relatives.

  6. The argonaut shell: gas-mediated buoyancy control in a pelagic octopus

    PubMed Central

    Finn, Julian K.; Norman, Mark D.

    2010-01-01

    Argonauts (Cephalopoda: Argonautidae) are a group of rarely encountered open-ocean pelagic octopuses with benthic ancestry. Female argonauts inhabit a brittle ‘paper nautilus’ shell, the role of which has puzzled naturalists for millennia. The primary role attributed to the shell has been as a receptacle for egg deposition and brooding. Our observations of wild argonauts have revealed that the thin calcareous shell also functions as a hydrostatic structure, employed by the female argonaut to precisely control buoyancy at varying depths. Female argonauts use the shell to ‘gulp’ a measured volume of air at the sea surface, seal off the captured gas using flanged arms and forcefully dive to a depth where the compressed gas buoyancy counteracts body weight. This process allows the female argonaut to attain neutral buoyancy at depth and potentially adjust buoyancy to counter the increased (and significant) weight of eggs during reproductive periods. Evolution of this air-capture strategy enables this negatively buoyant octopus to survive free of the sea floor. This major shift in life mode from benthic to pelagic shows strong evolutionary parallels with the origins of all cephalopods, which attained gas-mediated buoyancy via the closed-chambered shells of the true nautiluses and their relatives. PMID:20484241

  7. Population dynamics and stock assessment for Octopus maya (Cephalopoda: Octopodidae) fishery in the Campeche Bank, Gulf of Mexico.

    PubMed

    Arreguín-Sánchez, F; Solís-Ramírez, M J; González de la Rosa, M E

    2000-01-01

    The octopus (Octopus maya) is one of the most important fish resources in the Mexican Gulf of Mexico with a mean annual yield of 9000 ton, and a reasonable number of jobs created; O. maya represents 80% of the total octopus catch, followed by Octopus vulgaris. There are two artisanal fleets based on Octopus maya and a middle-size fleet that covers both species. Catch-at-length structured data from the artisanal fleets, for the 1994 season (August 1st to December 15th) were used to analyze the O. maya population dynamics and stock and to estimate the current level of exploitation. Von Bertalanffy growth parameters were: L infinity = 252 mm, mantle length; K = 1.4 year-1; oscillation parameters C = 1.0, WP = 0.6; and tz = 0.842 years. A rough estimate of natural mortality was M = 2.2, total mortality from catch curve Z = 8.77, and exploitation rate F/Z = 0.75. This last value suggests an intensive exploitation, even when yield per recruit analysis indicates both fleets may increase the minimum legal size on about 10% to increase yields. The length-based VPA also shows that the stock is being exploited under its maximum acceptable biological limit. These apparently contradictory results are explained by biological and behavioral characteristics of this species. Because most females die after reproduction, a new gross estimation of natural mortality was computed as M = 3.3. The new estimate of exploitation rate was F/Z = 0.57. This new value coincides with results from the length-VPA and the Thompson and Bell methods, the former suggesting that a reduction of 20% in fishing mortality may provide larger yields. This fishery resource is fully exploited and current management measures must be revised to sustain and probably optimize yields.

  8. Immunohistochemical localization of two types of choline acetyltransferase in neurons and sensory cells of the octopus arm.

    PubMed

    Sakaue, Yuko; Bellier, Jean-Pierre; Kimura, Shin; D'Este, Loredana; Takeuchi, Yoshihiro; Kimura, Hiroshi

    2014-01-01

    Cholinergic structures in the arm of the cephalopod Octopus vulgaris were studied by immunohistochemistry using specific antisera for two types (common and peripheral) of acetylcholine synthetic enzyme choline acetyltransferase (ChAT): antiserum raised against the rat common type ChAT (cChAT), which is cross-reactive with molluscan cChAT, and antiserum raised against the rat peripheral type ChAT (pChAT), which has been used to delineate peripheral cholinergic structures in vertebrates, but not previously in invertebrates. Western blot analysis of octopus extracts revealed a single pChAT-positive band, suggesting that pChAT antiserum is cross-reactive with an octopus counterpart of rat pChAT. In immunohistochemistry, only neuronal structures of the octopus arm were stained by cChAT and pChAT antisera, although the pattern of distribution clearly differed between the two antisera. cChAT-positive varicose nerve fibers were observed in both the cerebrobrachial tract and neuropil of the axial nerve cord, while pChAT-positive varicose fibers were detected only in the neuropil of the axial nerve cord. After epitope retrieval, pChAT-positive neuronal cells and their processes became visible in all ganglia of the arm, including the axial and intramuscular nerve cords, and in ganglia of suckers. Moreover, pChAT-positive structures also became detectable in nerve fibers connecting the different ganglia, in smooth nerve fibers among muscle layers and dermal connective tissues, and in sensory cells of the suckers. These results suggest that the octopus arm has two types of cholinergic nerves: cChAT-positive nerves from brain ganglia and pChAT-positive nerves that are intrinsic to the arm.

  9. Wind-driven upwelling effects on cephalopod paralarvae: Octopus vulgaris and Loliginidae off the Galician coast (NE Atlantic)

    NASA Astrophysics Data System (ADS)

    Otero, Jaime; Álvarez-Salgado, X. Antón; González, Ángel F.; Souto, Carlos; Gilcoto, Miguel; Guerra, Ángel

    2016-02-01

    Circulation patterns of coastal upwelling areas may have central consequences for the abundance and cross-shelf transport of the larval stages of many species. Previous studies have provided evidences that larvae distribution results from a combination of subtidal circulation, species-specific behaviour and larval sources. However, most of these works were conducted on organisms characterised by small-sized and abundant early life phases. Here, we studied the influence of the hydrography and circulation of the Ría de Vigo and adjacent shelf (NW Iberian upwelling system) on the paralarval abundance of two contrasting cephalopods, the benthic common octopus (Octopus vulgaris) and the pelagic squids (Loliginidae). We sampled repeatedly a cross-shore transect during the years 2003-2005 and used zero inflated models to accommodate the scarcity and patchy distribution of cephalopod paralarvae. The probability of catching early stages of both cephalopods was higher at night. Octopus paralarvae were more abundant in the surface layer at night whereas loliginids preferred the bottom layer regardless of the sampling time. Abundance of both cephalopods increased when shelf currents flowed polewards, water temperature was high and water column stability was low. The probability of observing an excess of zero catches decreased during the year for octopus and at high current speed for loliginids. In addition, the circulation pattern conditioned the body size distribution of both paralarvae; while the average size of the captured octopuses increased (decreased) with poleward currents at daylight (nighttime), squids were smaller with poleward currents regardless of the sampling time. These results contribute to the understanding of the effects that the hydrography and subtidal circulation of a coastal upwelling have on the fate of cephalopod early life stages.

  10. De Novo Transcriptome Sequencing of the Octopus vulgaris Hemocytes Using Illumina RNA-Seq Technology: Response to the Infection by the Gastrointestinal Parasite Aggregata octopiana

    PubMed Central

    Castellanos-Martínez, Sheila; Arteta, David; Catarino, Susana; Gestal, Camino

    2014-01-01

    Background Octopus vulgaris is a highly valuable species of great commercial interest and excellent candidate for aquaculture diversification; however, the octopus’ well-being is impaired by pathogens, of which the gastrointestinal coccidian parasite Aggregata octopiana is one of the most important. The knowledge of the molecular mechanisms of the immune response in cephalopods, especially in octopus is scarce. The transcriptome of the hemocytes of O. vulgaris was de novo sequenced using the high-throughput paired-end Illumina technology to identify genes involved in immune defense and to understand the molecular basis of octopus tolerance/resistance to coccidiosis. Results A bi-directional mRNA library was constructed from hemocytes of two groups of octopus according to the infection by A. octopiana, sick octopus, suffering coccidiosis, and healthy octopus, and reads were de novo assembled together. The differential expression of transcripts was analysed using the general assembly as a reference for mapping the reads from each condition. After sequencing, a total of 75,571,280 high quality reads were obtained from the sick octopus group and 74,731,646 from the healthy group. The general transcriptome of the O. vulgaris hemocytes was assembled in 254,506 contigs. A total of 48,225 contigs were successfully identified, and 538 transcripts exhibited differential expression between groups of infection. The general transcriptome revealed genes involved in pathways like NF-kB, TLR and Complement. Differential expression of TLR-2, PGRP, C1q and PRDX genes due to infection was validated using RT-qPCR. In sick octopuses, only TLR-2 was up-regulated in hemocytes, but all of them were up-regulated in caecum and gills. Conclusion The transcriptome reported here de novo establishes the first molecular clues to understand how the octopus immune system works and interacts with a highly pathogenic coccidian. The data provided here will contribute to identification of biomarkers

  11. Hyperpolarization-activated, mixed-cation current (I(h)) in octopus cells of the mammalian cochlear nucleus.

    PubMed

    Bal, R; Oertel, D

    2000-08-01

    Octopus cells in the posteroventral cochlear nucleus of mammals detect the coincidence of synchronous firing in populations of auditory nerve fibers and convey the timing of that coincidence with great temporal precision. Earlier recordings in current clamp have shown that two conductances contribute to the low input resistance and therefore to the ability of octopus cells to encode timing precisely, a low-threshold K(+) conductance and a hyperpolarization-activated mixed-cation conductance, g(h). The present experiments describe the properties of g(h) in octopus cells as they are revealed under voltage clamp with whole-cell, patch recordings. The hyperpolarization-activated current, I(h), was blocked by extracellular Cs(+) (5 mM) and 4-(N-ethyl-N-phenylamino)-1,2-dimethyl-6-(methylamino) pyridinium chloride (50-100 nM) but not by extracellular Ba(2+) (2 mM). The reversal potential for I(h) in octopus cells under normal physiological conditions was -38 mV. Increasing the extracellular potassium concentration from 3 to 12 mM shifted the reversal potential to -26 mV; lowering extracellular sodium concentration from 138 to 10 mM shifted the reversal potential to -77 mV. These pharmacological and ion substitution experiments show that I(h) in octopus cells is a mixed-cation current that resembles I(h) in other neurons and in heart muscle cells. Under control conditions when cells were perfused intracellularly with ATP and GTP, I(h) had an activation threshold between about -35 to -40 mV and became fully activated at -110 mV. The maximum conductance associated with hyperpolarizing voltage steps to -112 mV ranged from 87 to 212 nS [150 +/- 30 (SD) nS, n = 36]. The voltage dependence of g(h) obtained from peak tail currents is fit by a Boltzmann function with a half-activation potential of -65 +/- 3 mV and a slope factor of 7. 7 +/- 0.7. This relationship reveals that g(h) was activated 41% at the mean resting potential of octopus cells, -62 mV, and that at rest I

  12. Neuroendocrine–Immune Systems Response to Environmental Stressors in the Cephalopod Octopus vulgaris

    PubMed Central

    Di Cosmo, Anna; Polese, Gianluca

    2016-01-01

    Under a continuous changing environment, animals are challenged with stresses and stimuli which demanding adaptation at behavioral and physiological levels. The adaptation strategies are finely regulated by animal nervous, endocrine, and immune systems. Although it's been established by now the usage of integrative approach to the study the endocrine and nervous systems (neuroendocrine), yet our understanding of how they cooperate with the immune system remains far from complete. The possible role that immune system plays as a component of the network has only been recognized recently. Octopus vulgaris is an important member of cephalopods and is considered as a model species, with considerable information about the neuroendocrine and immune systems. In the current review, we anticipate to shed light on the complexity and cross talk among the three systems and how they cooperate in setting physiological response to stresses-stimuli in O. vulgaris as a target species and primary example. PMID:27733834

  13. The giant deep-sea octopus Haliphron atlanticus forages on gelatinous fauna

    PubMed Central

    Hoving, H.J.T.; Haddock, S.H.D.

    2017-01-01

    Feeding strategies and predator-prey interactions of many deep-sea pelagic organisms are still unknown. This is also true for pelagic cephalopods, some of which are very abundant in oceanic ecosystems and which are known for their elaborate behaviors and central role in many foodwebs. We report on the first observations of the giant deep-sea octopus Haliphron atlanticus with prey. Using remotely operated vehicles, we saw these giant octopods holding medusae in their arms. One of the medusae could be identified as Phacellophora camtschatica (the egg-yolk jelly). Stomach content analysis confirmed predation on cnidarians and gelatinous organisms. The relationship between medusae and H. atlanticus is discussed, also in comparison with other species of the Argonautoidea, all of which have close relationships with gelatinous zooplankton. PMID:28344325

  14. A review of simultaneous visual discrimination as a method of training octopuses.

    PubMed

    Boal, J G

    1996-05-01

    I have presented a review and critique of the procedures employed in simultaneous discrimination training experiments using octopuses as subjects. Procedural variables were analyzed statistically for their influence on experimental outcome. The variables most significantly associated with successful discriminations included use of a specific start location for subjects, shock as negative reinforcement, fewer trials per session, more sessions per day, and discriminations based on stimulus brightness. No experiment controlled all potential sources of inadvertent cues, and subjects' performances appeared to be sensitive to exact procedural details. The most common practice diminishing evidence for learning involved reward that coincided with the subject's pre-existing preferences. I found no evidence that sub-optimal experimental designs biased experimental outcomes in any significant and systematic way. Although there is sufficient reason for rejecting results of published simultaneous discrimination training experiments, careful conclusive experiments remain to be performed.

  15. RNA editing underlies temperature adaptation in K+ channels from polar octopuses.

    PubMed

    Garrett, Sandra; Rosenthal, Joshua J C

    2012-02-17

    To operate in the extreme cold, ion channels from psychrophiles must have evolved structural changes to compensate for their thermal environment. A reasonable assumption would be that the underlying adaptations lie within the encoding genes. Here, we show that delayed rectifier K(+) channel genes from an Antarctic and a tropical octopus encode channels that differ at only four positions and display very similar behavior when expressed in Xenopus oocytes. However, the transcribed messenger RNAs are extensively edited, creating functional diversity. One editing site, which recodes an isoleucine to a valine in the channel's pore, greatly accelerates gating kinetics by destabilizing the open state. This site is extensively edited in both Antarctic and Arctic species, but mostly unedited in tropical species. Thus adenosine-to-inosine RNA editing can respond to the physical environment.

  16. Hairy suckers: the surface microstructure and its possible functional significance in the Octopus vulgaris sucker

    PubMed Central

    Appel, Esther

    2014-01-01

    Summary Octopus suckers are able to attach to any smooth surface and many rough surfaces. Here, we have discovered that the sucker surface, which has been hypothesised to be responsible for sealing the orifice during adhesion, is not smooth as previously assumed, but is completely covered by a dense network of hair-like micro-outgrowths. This finding is particularly important because it provides another demonstration of the role of hair-structures in a sealing mechanism in water, similar to that previously described for clingfish and abalones. Moreover, the discovered hairs may provide an additional adhesive mechanism that works in concert with suction. The discovered surface structures might be potentially interesting for biomimetics of novel technical suction cups with improved adhesion capabilities on non-smooth surfaces. PMID:24991492

  17. Delineation of an octopus-like thrombus attached to the eustachian valve.

    PubMed

    Kalcik, Macit; Toprak, Cüneyt; Ozan Gursoy, M; Yesin, Mahmut; Ocal, Lutfi; Eren, Hayati; Özkan, Mehmet

    2014-04-01

    Eustachian valve (EV) is a vestige of the valve of the inferior vena cava which directs the umbilical vein blood through open foramen ovale in fetal life. Following birth it gradually regresses, but it may persist in variable size, shape, and thickness as a functionless and benign structure. However, there are reports suggesting that persistent EV may not be completely innocent. It has been accused of being a predisposing cause of patent foramen ovale and paradoxical embolism and also interfering with transseptal interventional procedures. It may serve as a site of infective vegetations and be mistaken as a tumor or thrombus. In the present case, an octopus-like thrombus attached to the EV was delineated with the utility of two-dimensional and real time three-dimensional transesophageal echocardiography. EV was considered to play an essential role in preventing potential pulmonary embolism.

  18. Biometrical relationships in developing eggs and neonates of Octopus vulgaris in relation to parental diet

    NASA Astrophysics Data System (ADS)

    Márquez, Lorenzo; Quintana, Daniel; Lorenzo, Antonio; Almansa, Eduardo

    2013-09-01

    Captive Octopus vulgaris adults were fed three mono-diets based on pilchard, crab and squid and allowed to grow until reproduction under controlled temperature. Spawns from each dietary treatment were isolated, and the embryonic development, egg length, width and wet weight, in addition to neonate dry weight, dorsal mantle length and ventral mantle length were monitored. Pilchard-diet spawns developed faster in terms of thermal time. Initial egg wet weight was higher for squid and crab diets. Irrespective of the parental diet, eggs passed through a swelling process so that egg width and wet weight increased in a nonlinear way, whereas egg length was left nearly unaffected. Egg length and initial wet weight showed a high correlation with neonate dry weight. Egg length, even at advanced incubation, can be used as a good proxy for neonate dry weight, this fact having potential implications for the ecological and aquaculture research on O. vulgaris.

  19. The giant deep-sea octopus Haliphron atlanticus forages on gelatinous fauna.

    PubMed

    Hoving, H J T; Haddock, S H D

    2017-03-27

    Feeding strategies and predator-prey interactions of many deep-sea pelagic organisms are still unknown. This is also true for pelagic cephalopods, some of which are very abundant in oceanic ecosystems and which are known for their elaborate behaviors and central role in many foodwebs. We report on the first observations of the giant deep-sea octopus Haliphron atlanticus with prey. Using remotely operated vehicles, we saw these giant octopods holding medusae in their arms. One of the medusae could be identified as Phacellophora camtschatica (the egg-yolk jelly). Stomach content analysis confirmed predation on cnidarians and gelatinous organisms. The relationship between medusae and H. atlanticus is discussed, also in comparison with other species of the Argonautoidea, all of which have close relationships with gelatinous zooplankton.

  20. Elemental characterization of tissues of Octopus vulgaris along the Portuguese coast.

    PubMed

    Napoleão, P; Pinheiro, T; Sousa Reis, C

    2005-06-01

    The concentrations of V, Mn, Fe, Ni, Cu, Zn, As, Se, Mo, and Pb were measured in digestive gland (DG), branchial hearts (BH), gill (G), and muscle (M) of Octopus vulgaris Cuvier, 1797 caught in three fishing areas of the Portuguese coast, Viana do Castelo, Cascais, and Santa Luzia, for 2 years. The elemental concentrations measured for the different tissues were in accordance with values reported in the literature. The digestive gland presented high concentration levels of Fe, Cu, and Zn, while the branchial hearts showed elevated levels of V, Ni, Mo, as well as Fe and Cu. Significant variations in As, V, Cu, Mo, and Pb tissue concentrations were observed for animals originated from different sampling sites. Pb and As determined in the digestive gland and branchial hearts of animals from Cascais and Santa Luzia, can reflect local environmental characteristics. The variability observed in the elemental concentrations may be useful to further assess the species susceptibility to environmental conditions.

  1. OCTOPUS, a polarly localised membrane-associated protein, regulates phloem differentiation entry in Arabidopsis thaliana.

    PubMed

    Truernit, Elisabeth; Bauby, Hélène; Belcram, Katia; Barthélémy, Julien; Palauqui, Jean-Christophe

    2012-04-01

    Vascular development is embedded into the developmental context of plant organ differentiation and can be divided into the consecutive phases of vascular patterning and differentiation of specific vascular cell types (phloem and xylem). To date, only very few genetic determinants of phloem development are known. Here, we identify OCTOPUS (OPS) as a potentiator of phloem differentiation. OPS is a polarly localised membrane-associated protein that is initially expressed in provascular cells, and upon vascular cell type specification becomes restricted to the phloem cell lineage. OPS mutants display a reduction of cotyledon vascular pattern complexity and discontinuous phloem differentiation, whereas OPS overexpressers show accelerated progress of cotyledon vascular patterning and phloem differentiation. We propose that OPS participates in vascular differentiation by interpreting longitudinal signals that lead to the transformation of vascular initials into differentiating protophloem cells.

  2. Identical linkage and cooperativity of oxygen and carbon monoxide binding to Octopus dofleini hemocyanin

    SciTech Connect

    Connelly, P.R.; Gill, S.J.; Miller, K.I.; Zhou, G.; van Holde, K.E. )

    1989-02-21

    Employment of high-precision thin-layer methods has enabled detailed functional characterization of oxygen and carbon monoxide binding for (1) the fully assembled form with 70 binding sites and (2) the isolated chains with 7 binding sites of octopus dofleini hemocyanin. The striking difference in the cooperativities of the two ligands for the assembled decamer is revealed through an examination of the binding capacities and the partition coefficient, determined as functions of the activities of both ligands. A global analysis of the data sets supported by a two-state allosteric model assuming an allosteric unit of 7. Higher level allosteric interactions were not indicated. This contrasts to results obtained for arthropod hemocyanins. Oxygen and carbon monoxide experiments performed on the isolated subunit chain confirmed the presence of functional heterogeneity reported previously. The analysis shows two types of binding sites in the ratio of 4:3.

  3. Neuroendocrine-Immune Systems Response to Environmental Stressors in the Cephalopod Octopus vulgaris.

    PubMed

    Di Cosmo, Anna; Polese, Gianluca

    2016-01-01

    Under a continuous changing environment, animals are challenged with stresses and stimuli which demanding adaptation at behavioral and physiological levels. The adaptation strategies are finely regulated by animal nervous, endocrine, and immune systems. Although it's been established by now the usage of integrative approach to the study the endocrine and nervous systems (neuroendocrine), yet our understanding of how they cooperate with the immune system remains far from complete. The possible role that immune system plays as a component of the network has only been recognized recently. Octopus vulgaris is an important member of cephalopods and is considered as a model species, with considerable information about the neuroendocrine and immune systems. In the current review, we anticipate to shed light on the complexity and cross talk among the three systems and how they cooperate in setting physiological response to stresses-stimuli in O. vulgaris as a target species and primary example.

  4. RNA Editing Underlies Temperature Adaptation in K+ Channels from Polar Octopuses

    PubMed Central

    Garrett, Sandra; Rosenthal, Joshua J.C.

    2014-01-01

    To operate in the extreme cold, ion channels from psychrophiles must have evolved structural changes to compensate for their thermal environment. A reasonable assumption would be that the underlying adaptations lie within the encoding genes. Here we show that delayed rectifier K+ channel genes from an Antarctic and a tropical octopus encode channels that differ at only four positions and display very similar behavior when expressed in Xenopus oocytes. However, the transcribed mRNAs are extensively edited, creating functional diversity. One editing site, which recodes an isoleucine to a valine in the channel’s pore, greatly accelerates gating kinetics by destabilizing the open state. This site is extensively edited in both Antarctic and Arctic species, but mostly unedited in tropical species. Thus A-to-I RNA editing can respond to the physical environment. PMID:22223739

  5. Functional and comparative assessments of the octopus learning and memory system.

    PubMed

    Hochner, Binyamin

    2010-01-01

    The octopus and its close relatives the cuttlefish and squid are the most advanced of the invertebrates, possessing the largest brains both in weight and cell numbers. Here I review recent studies of the neurophysiological properties of the vertical lobe system (VL) in the cephalopod brain, a system already thought to be dedicated to learning and memory. Summarizing from the point of view of comparative evolution, I relate these results to other systems where anatomical and electrophysiological data are available, mainly the insect mushroom bodies and the mammalian hippocampus. The emerging results suggest that a convergent evolutionary process has resulted in similar neural organization and activity-dependent long-term synaptic plasticity in all these learning and memory systems, even though the invertebrate systems conserve their typical anatomical and electrophysiological features. And finally, functional inferences based on the comparison with the insect mushroom.

  6. Convergent inputs to Octopus oculomotor neurones demonstrated in a brain slice preparation.

    PubMed

    Williamson, R; Budelmann, B U

    1991-01-02

    A brain slice preparation was developed to permit recordings to be made from neurones in the anterior lateral pedal lobe of the octopus CNS. These are the first intracellular recordings obtained from identified neurones in the cephalopod CNS. The neurones had membrane resting potentials of around -40 mV and action potentials up to 20 mV in amplitude. Spontaneous synaptic potentials could be seen in some cells. All of the oculomotor neurones, identified by stimulation of the anterior oculomotor nerve to evoke an antidromic potential, received an excitatory input from the visual system, shown by electrical stimulation of the optic tract, and some also received an excitatory input from the statocyst, as shown by electrical stimulation of the macula nerve.

  7. Relationship between photoreceptor terminations and centrifugal neurons in the optic lobe of octopus.

    PubMed

    Saidel, W M

    1979-01-01

    Retinal bundles, connecting the retina of the octopus to the ipsilateral optic lobe, contain both retinal photoreceptor axons that terminate in the optic lobe and centrifugal axons whose cell bodies lie within the lobe. Staining axonal elements in proximal stubs of individual retinal bundles by cobalt diffusion and subsequent sulphide treatment reveals the topographic relationship between afferent terminals and centrifugal cell bodies. At the outer border of the plexiform layer, stained terminal bags (photoreceptor axon enlargements), an indicator of photoreceptor terminal spread within this layer, overlap stained centrifugal cell bodies located within the inner granule layer. The details of this overlap indicate a dorsoventral representation of each retinal bundle within the optic lobe cortex.

  8. Neuronal and synaptic organization in the gravity receptor system of the statocyst of Octopus vulgaris.

    PubMed

    Colmers, W F

    1977-12-28

    The neuronal and synaptic organization of the sensory epithelium (macula) of the gravity receptor system of Octopus vulgaris was investigated by serial electron microscopic reconstruction. Three different types of afferent neurons, unipolar, bipolar, and multipolar, are described. Afferent synapses exist between the secondary sensory cells (hair cells) and the afferent neurons. Consequently, the neurons are first-order neurons. Two morphologically distinct types of afferent synapses could be identified: the most common type, present on every hair cell, has a finger-like postsynaptic process; the second type, which does not occur on every hair cell, has a flat or somewhat curved postsynaptic process. As a rule, the hair cells each form synapses with more than one afferent neuron. The neurons, in turn, form synapses with more than one hair cell. A complicated arrangement of efferent synapses was found at the level of both the hair cells and the neurons. The results are discussed with reference to their physiological consequences.

  9. [The modalities of the sexual cycle of Octopus vulgaris in the southern Moroccan Atlantic (Tantan, Boujdour)].

    PubMed

    Idrissi, Farah Hounaida; Koueta, Noussithé; Idhalla, Mohamed; Belghyti, Driss; Bencherifi, Salah

    2006-11-01

    The reproduction of Octopus vulgaris between Tan Tan and Boujdour is studied. The samples used are sorted monthly from commercial catches of coastal trawlers operating in this area from December 2001 to May 2003. The study shows that sexual maturity is in advance for males than for females. Two spawning periods are made out by the follow-up of the RGS: a spring period from March to July, and an autumnal period, which is less intense, between September and October. The division of spermatogonia and spermatocytes reaches its maximal intensity in July and December, whereas the spermiogenesis is active until the time of mating. The vitellogenesis starts in mid-December and extends until the following spawning period. This reveals a later gonadic development for females than for males; approximately seven months for females and three months for males.

  10. PGE from Octopus aegina Induces Apoptosis in Ehrlich's Ascites Carcinoma of Mice.

    PubMed

    Karthigayan, S; Balasubashini, M Sri; Balasubramanian, T; Somasundaram, S T

    2007-01-01

    ABSTRACT The present study was carried out to assess the antitumor effect of venomous peptide from the cephalopod Octopus aegina on Ehrlich's ascites carcinoma (EAC). Male albino Swiss mice were used in the present study. Four groups of animals were treated with three doses of the sublethal dose of venom, 15, 75, and 150 mug/kg body weight (intraperitoneal injection), along with the standard drug 5-fluorouracil (20 mg/kg b.w.). After 10 days of treatment, six animals from each group were sacrificed for the biochemical analysis and the rest were left to calculate the mean survival time. In EAC-bearing mice, mean lifespan, tumor volume, hemoglobin, red blood cells, and lymphocytes were significantly decreased when compared to the normal animals. While body weight, neutrophils, and viable tumor cell count were increased in the EAC-bearing mice, these changes were brought back to near normal levels in different treatment groups. The macromolecule concentration of peritoneal cells, such as DNA, RNA, and protein, were altered in the EAC-bearing mice and observed to be near normal in the treatment groups. The caspase-3 activity was significantly increased in the peritoneal cells of the treatment groups when compared to the EAC-bearing mice. The role of apoptotic cascade in EAC cell death was confirmed by the DNA fragmentation on agarose gel. Apart from the antitumor effect, octopus venom reduced the tumor burden on the liver and altered the changes in the activities of alanine transaminase (ALT), aspartate transaminase (AST), and alkaline phosphatase (ALP). Therefore, the venom from O. aegina has a potential antitumor effect on the EAC-bearing mice.

  11. Thermopreference, tolerance and metabolic rate of early stages juvenile Octopus maya acclimated to different temperatures.

    PubMed

    Noyola, Javier; Caamal-Monsreal, Claudia; Díaz, Fernando; Re, Denisse; Sánchez, Adolfo; Rosas, Carlos

    2013-01-01

    Thermopreference, tolerance and oxygen consumption rates of early juveniles Octopus maya (O. maya; weight range 0.38-0.78g) were determined after acclimating the octopuses to temperatures (18, 22, 26, and 30°C) for 20 days. The results indicated a direct relationship between preferred temperature (PT) and acclimated temperature, the PT was 23.4°C. Critical Thermal Maxima, (CTMax; 31.8±1.2, 32.7±0.9, 34.8±1.4 and 36.5±1.0) and Critical Thermal Minima, (CTMin; 11.6±0.2, 12.8±0.6, 13.7±1.0, 19.00±0.9) increased significantly (P<0.05) with increasing acclimation temperatures. The endpoint for CTMax was ink release and for CTMin was tentacles curled, respectively. A thermal tolerance polygon over the range of 18-30°C resulted in a calculated area of 210.0°C(2). The oxygen consumption rate increased significantly α=0.05 with increasing acclimation temperatures between 18 and 30°C. Maximum and minimum temperature quotients (Q10) were observed between 26-30°C and 22-26°C as 3.03 and 1.71, respectively. These results suggest that O. maya has an increased capability for adapting to moderate temperatures, and suggest increased culture potential in subtropical regions southeast of México.

  12. Behavioural and immunological responses to an immune challenge in Octopus vulgaris.

    PubMed

    Locatello, Lisa; Fiorito, Graziano; Finos, Livio; Rasotto, Maria B

    2013-10-02

    Behavioural and immunological changes consequent to stress and infection are largely unexplored in cephalopods, despite the wide employment of species such as Octopus vulgaris in studies that require their manipulation and prolonged maintenance in captivity. Here we explore O. vulgaris behavioural and immunological (i.e. haemocyte number and serum lysozyme activity) responses to an in vivo immune challenge with Escherichia coli lipopolysaccharides (LPS). Behavioural changes of immune-treated and sham-injected animals were observed in both sight-allowed and isolated conditions, i.e. visually interacting or not with a conspecific. Immune stimulation primarily caused a significant increase in the number of circulating haemocytes 4h after the treatment, while serum lysozyme activity showed a less clear response. However, the effect of LPS on the circulating haemocytes begins to vanish 24h after injection. Our observations indicate a significant change in behaviour consequent to LPS administration, with treated octopuses exhibiting a decrease of general activity pattern when kept in the isolated condition. A similar decrease was not observed in the sight-allowed condition, where we noticed a specific significant reduction only in the time spent to visually interact with the conspecific. Overall, significant, but lower, behavioural and immunological effects of injection were detected also in sham-injected animals, suggesting a non-trivial susceptibility to manipulation and haemolymph sampling. Our results gain importance in light of changes of the regulations for the use of cephalopods in scientific procedures that call for the prompt development of guidelines, covering many aspects of cephalopod provision, maintenance and welfare.

  13. Comparison of Reconstruction and Control algorithms on the ESO end-to-end simulator OCTOPUS

    NASA Astrophysics Data System (ADS)

    Montilla, I.; Béchet, C.; Lelouarn, M.; Correia, C.; Tallon, M.; Reyes, M.; Thiébaut, É.

    Extremely Large Telescopes are very challenging concerning their Adaptive Optics requirements. Their diameters, the specifications demanded by the science for which they are being designed for, and the planned use of Extreme Adaptive Optics systems, imply a huge increment in the number of degrees of freedom in the deformable mirrors. It is necessary to study new reconstruction algorithms to implement the real time control in Adaptive Optics at the required speed. We have studied the performance, applied to the case of the European ELT, of three different algorithms: the matrix-vector multiplication (MVM) algorithm, considered as a reference; the Fractal Iterative Method (FrIM); and the Fourier Transform Reconstructor (FTR). The algorithms have been tested on ESO's OCTOPUS software, which simulates the atmosphere, the deformable mirror, the sensor and the closed-loop control. The MVM is the default reconstruction and control method implemented in OCTOPUS, but it scales in O(N2) operations per loop so it is not considered as a fast algorithm for wave-front reconstruction and control on an Extremely Large Telescope. The two other methods are the fast algorithms studied in the E-ELT Design Study. The performance, as well as their response in the presence of noise and with various atmospheric conditions, has been compared using a Single Conjugate Adaptive Optics configuration for a 42 m diameter ELT, with a total amount of 5402 actuators. Those comparisons made on a common simulator allow to enhance the pros and cons of the various methods, and give us a better understanding of the type of reconstruction algorithm that an ELT demands.

  14. Control of GnRH expression in the olfactory lobe of Octopus vulgaris.

    PubMed

    Di Cristo, Carlo; De Lisa, Emilia; Di Cosmo, Anna

    2009-03-01

    In the cephalopod mollusk Octopus vulgaris, the gonadotropic hormone released by the optic gland controls sexual maturity. Several lobes of the central nervous system control the activity of this gland. In one of these lobes, the olfactory lobe, a gonadotropin releasing hormone (GnRH) neuronal system has been described. We assume that several inputs converge on the olfactory lobes in order to activate GnRH neurons and that a glutamatergic system mediates the integration of stimuli on these neuropeptidergic neurons. The presence of N-methyl-d-aspartate (NMDA) receptor immunoreactivity in the neuropil of olfactory lobes and in the fibers of the optic gland nerve, along with the GnRH nerve endings strongly supports this hypothesis. A distinctive role in the control of GnRH secretion has also been attributed, in vertebrates, to nitric oxide (NO). The lobes and nerves involved in the nervous control of reproduction in Octopus contain nitric oxide synthase (NOS). Using a set of experiments aimed at manipulate a putative l-glutamate/NMDA/NO signal transduction pathway, we have demonstrated, by quantitative real-time PCR, that NMDA enhances the expression of GnRH mRNA in a dose-response manner. The reverting effect of a selective antagonist of NMDA receptors (NMDARs), 2-amino-5-phosphopentanoic acid (D-APV), confirms that such an enhancing action is a NMDA receptor-mediated response. Nitric oxide and calcium also play a positive role on GnRH mRNA expression. The results suggest that in Octopusl-glutamate could be a key molecule in the nervous control of sexual maturation.

  15. Lactogenic Activity of an Enzymatic Hydrolysate from Octopus vulgaris and Carica papaya in SD Rats.

    PubMed

    Cai, Bingna; Chen, Hua; Sun, Han; Sun, Huili; Wan, Peng; Chen, Deke; Pan, Jianyu

    2015-11-01

    The traditional Chinese medicine theory believes that octopus papaya soup can stimulate milk production in lactating women. The objective of this study was to determine whether dietary supplementation with an enzymatic hydrolysate of Octopus vulgaris and Carica papaya (EHOC) could increase milk production and nutritional indexes in Sprague Dawley (SD) rats. Female SD rats (n = 24) were fed a control diet (n = 8), EHOC-supplemented diet, or a positive control diet (Shengruzhi) from day 10 of pregnancy to day 10 of lactation. Maternal serum, mammary gland (day 10 of lactation), milk, and pup weight (daily) were collected for analysis. Results showed that the EHOC diet obviously elevated daily milk yield and pup weight compared to the control group (P < .05). The EHOC diet was found to increase the concentration of prolactin (PRL), progesterone (P), estradiol (E2), and growth hormone (GH) significantly in the circulation and mammary gland. Mammary glands of EHOC-treated dams showed clear lobuloalveolar development and proliferation of myoepithelial cells, but no striking variations were observed among the groups. Furthermore, the nutrition content and immune globulin concentration in the milk of EHOC-supplemented dams were higher than those of the control group, especially the cholesterol, glucose, and IgG were higher by 44.98% (P < .001), 42.76% (P < .01), and 42.23% (P < .01), respectively. In conclusion, this article demonstrates that EHOC administration has beneficial effects on milk production in the dams and on performance of the dam and pup. These results indicate that EHOC could be explored as a potentially lactogenic nutriment for lactating women.

  16. Ionic currents underlying fast action potentials in the obliquely striated muscle cells of the octopus arm.

    PubMed

    Rokni, Dan; Hochner, Binyamin

    2002-12-01

    The octopus arm provides a unique model for neuromuscular systems of flexible appendages. We previously reported the electrical compactness of the arm muscle cells and their rich excitable properties ranging from fast oscillations to overshooting action potentials. Here we characterize the voltage-activated ionic currents in the muscle cell membrane. We found three depolarization-activated ionic currents: 1) a high-voltage-activated L-type Ca(2+) current, which began activating at approximately -35 mV, was eliminated when Ca(2+) was substituted by Mg(2+), was blocked by nifedipine, and showed Ca(2+)-dependent inactivation. This current had very rapid activation kinetics (peaked within milliseconds) and slow inactivation kinetics (tau in the order of 50 ms). 2) A delayed rectifier K(+) current that was totally blocked by 10 mM TEA and partially blocked by 10 mM 4-aminopyridine (4AP). This current exhibited relatively slow activation kinetics (tau in the order of 15 ms) and inactivated only partially with a time constant of ~150 ms. And 3) a transient A-type K(+) current that was totally blocked by 10 mM 4AP and was partially blocked by 10 mM TEA. This current exhibited very fast activation kinetics (peaked within milliseconds) and inactivated with a time constant in the order of 60 ms. Inactivation of the A-type current was almost complete at -40 mV. No voltage-dependent Na(+) current was found in these cells. The octopus arm muscle cells generate fast (~3 ms) overshooting spikes in physiological conditions that are carried by a slowly inactivating L-type Ca(2+) current.

  17. Evaluation of Octopus Polar Trend Analysis for detection of glaucomatous progression.

    PubMed

    Holló, Gábor; Naghizadeh, Farzaneh

    2014-01-01

    To investigate the clinical usefulness of Polar Trend Analysis (PTA) of the Octopus Field Analysis software for detection of glaucoma progression in medically treated glaucoma. One eye each of 52 participants underwent Octopus Normal G2 perimetry and imaging with the RTVue-100 optical coherence tomograph at 6-month intervals (median follow-up 5 years). The eyes were classified as progressors or nonprogressors with PTA, which graphically presents pointwise linear regression analysis of focal defect at the corresponding nerve fiber angle at the disc margin. Polar Trend Analysis progression was defined as more than 1 significantly progressing test point location per sector. Progression of the retinal nerve fiber layer thickness (RNFLT) and ganglion cell complex (GCC) thickness parameters were evaluated with linear regression analysis. Seventeen eyes were classified as PTA progressors (all in the inferotemporal or superotemporal areas or in both), and 35 eyes as nonprogressors. Frequencies of statistically significant RNFLT and GCC progressions did not differ significantly between the groups for any peripapillary area (p>0.05 for all comparisons). Significant inferior average RNFLT progression occurred in 50% of the PTA progressor eyes. Long-term measurement variability during the follow-up period was significantly higher in the PTA progressor group for inferior and superior GCC thickness and inferior average RNFLT (p<0.001 for all comparisons). In glaucoma, PTA may indicate glaucomatous progression earlier than linear regression analysis of the RNFLT and GCC parameters. It may already draw attention to glaucomatous progression when the alteration of the corresponding structural parameters is represented only by increased long-term variability.

  18. Mechanisms of onset responses in octopus cells of the cochlear nucleus: implications of a model.

    PubMed

    Cai, Y; Walsh, E J; McGee, J

    1997-08-01

    The octopus cells of the posteroventral cochlear nucleus receive inputs from auditory-nerve fibers and form one of the major ascending auditory pathways. They respond to acoustic and electrical stimulation transiently and are believed to carry temporal information in the precise timing of their action potentials. The mechanism whereby onset responses are generated is not clear. Proposals aimed at elucidating the mechanism range from neural circuitry and/or inhibition, "depolarization block" (or inactivation of Na+ channels), and the involvement of a 4-aminopyridine (4-AP)-sensitive, low-threshold channel (K(LT)). In the present study, we used a compartment model to investigate possible mechanisms. The model cell contains a soma, an axon, and four passive dendrites. Four kinds of ionic channels were included in the soma compartment: the Hodgkin-Huxley-like Na+ and K+ channels, a 4-AP-sensitive, low-threshold channel, K(LT), and a Cs+-sensitive, hyperpolarization-activated inward rectifier, Ih. DC currents and half-wave-rectified sine waves were used as stimuli. Our results showed that an onset response can be generated in the absence of neuronal circuitry of any form, thus suggesting that the onset response in octopus cells is regulated intrinsically. Among the many factors involved, low-input impedance, partly contributed by Ih, appears to be essential to the basic onset response pattern; also, the K(LT) conductance plays a major role, whereas the inactivation of Na+ channels probably plays only a secondary role. The dynamics of Ih also can modify the response pattern, but due to its slow kinetics, its role is probably limited to longer-term regulation under the conditions simulated in this study.

  19. Determination of the average orientation of DNA in the octopus sperm [ital Eledone] [ital cirrhossa] through polarized light scattering

    SciTech Connect

    Shapiro, D.B.; Maestre, M.F.; McClain, W.M.; Hull, P.G.; Shi, Y.; Quinby-Hunt, M.S.; Hearst, J.E.; Hunt, A.J. )

    1994-08-20

    The coupled-dipole approximation has been used to model polarized light-scattering data obtained from the sperm of the octopus [ital Eledone] [ital cirrhosa]. Mueller scattering-matrix elements (which describe how a sample alters the intensity and degree of polarization of scattered light) were measured as a function of angle. The sample was modeled as a helical fiber believed to correspond to a DNA protein complex. It was necessary to propose an inherent anisotropy in the polarizability of the fiber in order to fit the data. The direction of the principle axes of the polarizability were determined by comparing the model with experimental data. The results suggest that the 2-nm DNA fibers are perpendicular to the thick fiber that defines the helical geometry of the octopus sperm head.

  20. A numerical investigation of flow around octopus-like arms: near-wake vortex patterns and force development.

    PubMed

    Kazakidi, A; Vavourakis, V; Tsakiris, D P; Ekaterinaris, J A

    2015-01-01

    The fluid dynamics of cephalopods has so far received little attention in the literature, due to their complexity in structure and locomotion. The flow around octopuses, in particular, can be complicated due to their agile and dexterous arms, which frequently display some of the most diverse mechanisms of motion. The study of this flow amounts to a specific instance of the hydrodynamics problem for rough tapered cylinder geometries. The outstanding manipulative and locomotor skills of octopuses could inspire the development of advanced robotic arms, able to operate in fluid environments. Our primary aim was to study the hydrodynamic characteristics of such bio-inspired robotic models and to derive the hydrodynamic force coefficients as a concise description of the vortical flow effects. Utilizing computational fluid dynamic methods, the coefficients were computed on realistic morphologies of octopus-like arm models undergoing prescribed solid-body movements; such motions occur in nature for short durations in time, e.g. during reaching movements and exploratory behaviors. Numerical simulations were performed on translating, impulsively rotating, and maneuvering arms, around which the flow field structures were investigated. The results reveal in detail the generation of complex vortical flow structures around the moving arms. Hydrodynamic forces acting on a translating arm depend on the angle of incidence; forces generated during impulsive rotations of the arms are independent of their exact morphology and the angle of rotation; periodic motions based on a slow recovery and a fast power stroke are able to produce considerable propulsive thrust while harmonic motions are not. Parts of these results have been employed in bio-inspired models of underwater robotic mechanisms. This investigation may further assist elucidating the hydrodynamics underlying aspects of octopus locomotion and exploratory behaviors.

  1. Respiratory failure and lethal hypotension due to blue-ringed octopus and tetrodotoxin envenomation observed and counteracted in animal models.

    PubMed

    Flachsenberger, W A

    The effects of crude blue-ringed octopus venom gland extract and tetrodotoxin (TTX) on anaesthetised rats and rabbits were studied. Paralysis of the respiratory musculature causing anoxia and cyanosis was overcome with positive, artificial respiration. The second lethal mechanism of the toxins: rapid and severe hypotension, had to be counteracted peripherally, since neural transmission had been drastically reduced by the toxins. Noradrenaline, d-amphetamine, phenylephrine and methoxamine, agonists acting on vascular adrenergic a-receptors, were tested.

  2. Immunohistochemical and biochemical evidence for the presence of serotonin-containing neurons and nerve fibers in the octopus arm.

    PubMed

    Bellier, Jean-Pierre; Xie, Yu; Farouk, Sameh Mohamed; Sakaue, Yuko; Tooyama, Ikuo; Kimura, Hiroshi

    2017-02-28

    The octopus arm contains a tridimensional array of muscles with a massive sensory-motor system. We herein provide the first evidence for the existence of serotonin (5-HT) in the octopus arm nervous system and investigated its distribution using immunohistochemistry. 5-HT-like immunoreactive (5-HT-lir) nerve cell bodies were exclusively localized in the cellular layer of the axial nerve cord. Those cell bodies emitted 5-HT-lir nerve fibers in the direction of the sucker, the intramuscular nerves cords, the ganglion of the sucker, and the intrinsic musculature. Others 5-HT-lir nerve fibers were observed in various tissues, including the cerebrobrachial tract, the skin, and the blood vessels. 5-HT was detected by high-performance liquid chromatography in various regions of the octopus arm at levels matching the density of 5-HT-lir staining. The absence of 5-HT-lir interconnections between the cerebrobrachial tract and the other components of the axial nerve cord suggests that two types of 5-HT-lir innervation exist in the arm. One type, which originates from the brain, may innervate the periphery through the cerebrobrachial tract. Another type, which originates in the cellular layer of the axial nerve cord, may form an intrinsic network in the arm. In addition, 5-HT-lir fibers likely emitted from the neuropil of the axial nerve cord were found to project into cells showing staining for peripheral choline acetyltransferase, a marker of sensory cells of the sucker. Taken together, these observations suggest that intrinsic 5-HT-lir innervation may participate in the sensory transmission in the octopus arm.

  3. Octopus photoreceptor membranes. Surface charge density and pK of the Schiff base of the pigments.

    PubMed

    Koutalos, Y; Ebrey, T G; Gilson, H R; Honig, B

    1990-08-01

    The chromophore of octopus rhodopsin is 11-cis retinal, linked via a protonated Schiff base to the protein backbone. Its stable photoproduct, metarhodopsin, has all-trans retinal as its chromphore. The Schiff base of acid metarhodopsin (lambda max = 510 nm) is protonated, whereas that of alkaline metarhodopsin (lambda max = 376 nm) is unprotonated. Metarhodopsin in photoreceptor membranes was titrated and the apparent pK of the Schiff base was measured at different ionic strengths. From these salt-dependent pKs the surface charge density of the octopus photoreceptor membranes and the intrinsic Schiff base pK of metarhodopsin were obtained. The surface charge density is sigma = -1.6 +/- 0.1 electronic charges per 1,000 A2. Comparison of the measured surface charge density with values from octopus rhodopsin model structures suggests that the measured value is for the extracellular surface and so the Schiff base in metarhodopsin is freely accessible to protons from the extracellular side of the membrane. The intrinsic Schiff base pK of metarhodopsin is 8.44 +/- 0.12, whereas that of rhodopsin is found to be 10.65 +/- 0.10 in 4.0 M KCl. These pK values are significantly higher than the pK value around 7.0 for a retinal Schiff base in a polar solvent; we suggest that a plausible mechanism to increase the pK of the retinal pigments is the preorganization of their chromophore-binding sites. The preorganized site stabilizes the protonated Schiff base with respect to the unprotonated one. The difference in the pK for the octopus rhodopsin compared with metarhodopsin is attributed to the relative freedom of the latter's chromophore-binding site to rearrange itself after deprotonation of the Schiff base.

  4. Octopus photoreceptor membranes. Surface charge density and pK of the Schiff base of the pigments.

    PubMed Central

    Koutalos, Y; Ebrey, T G; Gilson, H R; Honig, B

    1990-01-01

    The chromophore of octopus rhodopsin is 11-cis retinal, linked via a protonated Schiff base to the protein backbone. Its stable photoproduct, metarhodopsin, has all-trans retinal as its chromphore. The Schiff base of acid metarhodopsin (lambda max = 510 nm) is protonated, whereas that of alkaline metarhodopsin (lambda max = 376 nm) is unprotonated. Metarhodopsin in photoreceptor membranes was titrated and the apparent pK of the Schiff base was measured at different ionic strengths. From these salt-dependent pKs the surface charge density of the octopus photoreceptor membranes and the intrinsic Schiff base pK of metarhodopsin were obtained. The surface charge density is sigma = -1.6 +/- 0.1 electronic charges per 1,000 A2. Comparison of the measured surface charge density with values from octopus rhodopsin model structures suggests that the measured value is for the extracellular surface and so the Schiff base in metarhodopsin is freely accessible to protons from the extracellular side of the membrane. The intrinsic Schiff base pK of metarhodopsin is 8.44 +/- 0.12, whereas that of rhodopsin is found to be 10.65 +/- 0.10 in 4.0 M KCl. These pK values are significantly higher than the pK value around 7.0 for a retinal Schiff base in a polar solvent; we suggest that a plausible mechanism to increase the pK of the retinal pigments is the preorganization of their chromophore-binding sites. The preorganized site stabilizes the protonated Schiff base with respect to the unprotonated one. The difference in the pK for the octopus rhodopsin compared with metarhodopsin is attributed to the relative freedom of the latter's chromophore-binding site to rearrange itself after deprotonation of the Schiff base. PMID:2207250

  5. Identification of a Δ5-like fatty acyl desaturase from the cephalopod Octopus vulgaris (Cuvier 1797) involved in the biosynthesis of essential fatty acids.

    PubMed

    Monroig, Oscar; Navarro, Juan C; Dick, James R; Alemany, Frederic; Tocher, Douglas R

    2012-08-01

    Long-chain polyunsaturated fatty acids (LC-PUFA) have been identified as essential compounds for common octopus (Octopus vulgaris), but precise dietary requirements have not been determined due, in part, to the inherent difficulties of performing feeding trials on paralarvae. Our objective is to establish the essential fatty acid (EFA) requirements for paralarval stages of the common octopus through characterisation of the enzymes of endogenous LC-PUFA biosynthetic pathways. In this study, we isolated a cDNA with high homology to fatty acyl desaturases (Fad). Functional characterisation in recombinant yeast showed that the octopus Fad exhibited Δ5-desaturation activity towards saturated and polyunsaturated fatty acyl substrates. Thus, it efficiently converted the yeast's endogenous 16:0 and 18:0 to 16:1n-11 and 18:1n-13, respectively, and desaturated exogenously added PUFA substrates 20:4n-3 and 20:3n-6 to 20:5n-3 (EPA) and 20:4n-6 (ARA), respectively. Although the Δ5 Fad enables common octopus to produce EPA and ARA, the low availability of its adequate substrates 20:4n-3 and 20:3n-6, either in the diet or by limited endogenous synthesis from C(18) PUFA, might indicate that EPA and ARA are indeed EFA for this species. Interestingly, the octopus Δ5 Fad can also participate in the biosynthesis of non-methylene-interrupted FA, PUFA that are generally uncommon in vertebrates but have been found previously in marine invertebrates, including molluscs, and now also confirmed to be present in specific tissues of common octopus.

  6. Selection of reliable reference genes for RT-qPCR studies in Octopus vulgaris paralarvae during development and immune-stimulation.

    PubMed

    García-Fernández, P; Castellanos-Martínez, S; Iglesias, J; Otero, J J; Gestal, C

    2016-07-01

    The common octopus, Octopus vulgaris is a new candidate species for aquaculture. However, rearing of octopus paralarvae is hampered by high mortality and poor growth rates that impede its entire culture. The study of genes involved in the octopus development and immune response capability could help to understand the key of paralarvae survival and thus, to complete the octopus life cycle. Quantitative real-time PCR (RT-qPCR) is the most frequently tool used to quantify the gene expression because of specificity and sensitivity. However, reliability of RT-qPCR requires the selection of appropriate normalization genes whose expression must be stable across the different experimental conditions of the study. Hence, the aim of the present work is to evaluate the stability of six candidate genes: β-actin (ACT), elongation factor 1-α (EF), ubiquitin (UBI), β-tubulin (TUB), glyceraldehyde 3-phosphate dehydrogenase (GADPH) and ribosomal RNA 18 (18S) in order to select the best reference gene. The stability of gene expression was analyzed using geNorm, NormFinder and Bestkeeper, in octopus paralarvae of seven developmental stages (embryo, paralarvae of 0, 10, 15, 20, 30 and 34days) and paralarvae of 20days after challenge with Vibrio lentus and Vibrio splendidus. The results were validated by measuring the expression of PGRP, a stimuli-specific gene. Our results showed UBI, EF and 18S as the most suitable reference genes during development of octopus paralarvae, and UBI, ACT and 18S for bacterial infection. These results provide a basis for further studies exploring molecular mechanism of their development and innate immune defense. Copyright © 2016 Elsevier Inc. All rights reserved.

  7. Deep-sea octopus (Graneledone boreopacifica) conducts the longest-known egg-brooding period of any animal.

    PubMed

    Robison, Bruce; Seibel, Brad; Drazen, Jeffrey

    2014-01-01

    Octopuses typically have a single reproductive period and then they die (semelparity). Once a clutch of fertilized eggs has been produced, the female protects and tends them until they hatch. In most shallow-water species this period of parental care can last from 1 to 3 months, but very little is known about the brooding of deep-living species. In the cold, dark waters of the deep ocean, metabolic processes are often slower than their counterparts at shallower depths. Extrapolations from data on shallow-water octopus species suggest that lower temperatures would prolong embryonic development periods. Likewise, laboratory studies have linked lower temperatures to longer brooding periods in cephalopods, but direct evidence has not been available. We found an opportunity to directly measure the brooding period of the deep-sea octopus Graneledone boreopacifica, in its natural habitat. At 53 months, it is by far the longest egg-brooding period ever reported for any animal species. These surprising results emphasize the selective value of prolonged embryonic development in order to produce competitive hatchlings. They also extend the known boundaries of physiological adaptations for life in the deep sea.

  8. Histone H1-like protein and a testis-specific variant in the reproductive tracts of Octopus vulgaris.

    PubMed

    Faraone Mennella, Maria Rosaria; Farina, Benedetta; Irace, Maria Venezia; Di Cristo, Carlo; Di Cosmo, Anna

    2002-11-01

    In this study, we have identified a 28-kDa protein resembling the linker H1 in the testis and prostate of the reproductive system of Octopus vulgaris. This protein, OvH1, was partially purified by reverse phase high-pressure liquid chromatography (HPLC) of the perchloric acid extract from testis nuclei. It showed electrophoretic mobility, CD spectrum and amino acid composition highly comparable with those of the mammalian histone. Moreover, it was microheterogeneous, as resulted from prostate and testis HPLC and mass spectrometry analyses. Such analysis showed that in testis there are two H1 subfractions, which do not appear in the prostate. Amino acid composition of the major testis specific variant (OvH1t) showed high similarity with rat testis specific H1t. The histone-like nature of OvH1 was confirmed by its ability to bind DNA as tested both by circular dichroism and protection of the nucleic acid toward deoxyribonuclease I activity. The circular dichroism spectra of Octopus DNA in the absence and presence of increasing amounts of the protein showed a dose-dependent effect, leading to a progressive compactness of the polynucleotide. OvH1/DNA complexes were also resistant to nuclease digestion. The presence of H1 in the testis and prostate of the reproductive system of Octopus is discussed in light of the fact that there is a similarity between its behavior and that of vertebrates.

  9. Deep-Sea Octopus (Graneledone boreopacifica) Conducts the Longest-Known Egg-Brooding Period of Any Animal

    PubMed Central

    Robison, Bruce; Seibel, Brad; Drazen, Jeffrey

    2014-01-01

    Octopuses typically have a single reproductive period and then they die (semelparity). Once a clutch of fertilized eggs has been produced, the female protects and tends them until they hatch. In most shallow-water species this period of parental care can last from 1 to 3 months, but very little is known about the brooding of deep-living species. In the cold, dark waters of the deep ocean, metabolic processes are often slower than their counterparts at shallower depths. Extrapolations from data on shallow-water octopus species suggest that lower temperatures would prolong embryonic development periods. Likewise, laboratory studies have linked lower temperatures to longer brooding periods in cephalopods, but direct evidence has not been available. We found an opportunity to directly measure the brooding period of the deep-sea octopus Graneledone boreopacifica, in its natural habitat. At 53 months, it is by far the longest egg-brooding period ever reported for any animal species. These surprising results emphasize the selective value of prolonged embryonic development in order to produce competitive hatchlings. They also extend the known boundaries of physiological adaptations for life in the deep sea. PMID:25075745

  10. The octopus vertical lobe modulates short-term learning rate and uses LTP to acquire long-term memory.

    PubMed

    Shomrat, Tal; Zarrella, Ilaria; Fiorito, Graziano; Hochner, Binyamin

    2008-03-11

    Analyzing the processes and neuronal circuitry involved in complex behaviors in phylogenetically remote species can help us understand the evolution and function of these systems. Cephalopods, with their vertebrate-like behaviors but much simpler brains, are ideal for such an analysis. The vertical lobe (VL) of Octopus vulgaris is a pivotal brain station in its learning and memory system. To examine the organization of the learning and memory circuitry and to test whether the LTP that we discovered in the VL is involved in behavioral learning, we tetanized the VL to induce a global synaptic enhancement of the VL pathway. The effects of tetanization on learning and memory of a passive avoidance task were compared to those of transecting the same pathway. Tetanization accelerated and transection slowed short-term learning to avoid attacking a negatively reinforced object. However, both treatments impaired long-term recall the next day. Our results suggest that the learning and memory system in the octopus, as in mammals [9], is separated into short- and long-term memory sites. In the octopus, the two memory sites are not independent; the VL, which mediates long-term memory acquisition through LTP, also modulates the circuitry controlling behavior and short-term learning.

  11. Octopus, which owns the most advanced brain in invertebrates, has two members of vasopressin/oxytocin superfamily as in vertebrates.

    PubMed

    Takuwa-Kuroda, Kyoko; Iwakoshi-Ukena, Eiko; Kanda, Atsuhiro; Minakata, Hiroyuki

    2003-09-15

    A novel member of the vasopressin/oxytocin superfamily, octopressin (OP), has been isolated from Octopus vulgaris. Since another peptide of this superfamily, cephalotocin (CT), was isolated from the same species [Neurosci. Lett. 134 (1992) 191], Octopus has two members of the superfamily as in vertebrates, an observation made for the first time in invertebrates. Octopressin caused contractions of the Octopus peripheral tissues such as oviduct, aorta, rectum, etc. Cephalotocin had no effects on tested tissues. The octopressin and cephalotocin precursors were composed of a signal peptide, a nonapeptide, and a neurophysin domain-the typical structural organizations of the superfamily precursors. Reverse transcription polymerase chain reaction (RT-PCR)/Southern blot analysis revealed that octopressin mRNA was expressed in the supraesophageal and subesophageal brains, and the buccal and gastric ganglia. Cephalotocin mRNA was expressed mostly in the subesophageal brain. In situ hybridization in the brain showed that octopressin mRNA was localized in many lobes. Expression of cephalotocin mRNA was almost limited in the ventral median vasomotor lobe. Some of the neurons in this lobe are the source of the neurosecretory system of the vena cava, where cephalotocin was originally isolated. These results suggest that octopressin may be a multifunctional neuropeptide contributing to reproduction, cardiac circulation, and feeding. Cephalotocin may play important roles in metabolism, homeostasis, etc., as a neurohormone.

  12. Recordings from slices indicate that octopus cells of the cochlear nucleus detect coincident firing of auditory nerve fibers with temporal precision.

    PubMed

    Golding, N L; Robertson, D; Oertel, D

    1995-04-01

    Acoustic information in auditory nerve discharges is integrated in the cochlear nuclei, and ascends through several parallel pathways to higher centers. Octopus cells of the posteroventral cochlear nucleus form a pathway known to carry information in the timing of action potentials. Octopus cells have dendrites oriented to receive converging input from many auditory nerve fibers. In all 34 intracellular recordings from anatomically identified octopus cells in slices, shocks to the auditory nerve evoked brief, consistent, graded EPSPs. EPSPs were about 1 msec in duration. At all but the lowest shock strengths, the delays between shocks and the peaks of resultant EPSPs had SDs of 0.02 msec. Polysynaptic excitation, perhaps arising from the axon collaterals of octopus cells, was observed. No detectable glycinergic or GABAergic inhibition was evoked with shocks. The input resistances were low, around 10 M omega, voltage changes were rapid, with time constants of about 1 msec, and action potentials were small. The low input resistance resulted in part from a Cs(+)-sensitive conductance. In the presence of 10 or 15 mM extracellular Cs+ the time constants increased 20-fold in the hyperpolarizing voltage range. As several subthreshold inputs were required to produce suprathreshold responses, octopus cells detect the coincident firing of auditory nerve fibers. Under physiological conditions the low input resistance and resulting short time constant limit the time over which temporal summation of excitation from auditory nerve fibers can occur and thus provide temporal precision to electrical signaling.

  13. Prey Capture, Ingestion, and Digestion Dynamics of Octopus vulgaris Paralarvae Fed Live Zooplankton.

    PubMed

    Nande, Manuel; Presa, Pablo; Roura, Álvaro; Andrews, Paul L R; Pérez, Montse

    2017-01-01

    Octopus vulgaris is a species of great interest in research areas such as neurobiology, ethology, and ecology but also a candidate species for aquaculture as a food resource and for alleviating the fishing pressure on its wild populations. This study aimed to characterize the predatory behavior of O. vulgaris paralarvae and to quantify their digestive activity. Those processes were affordable using the video-recording analysis of 3 days post-hatching (dph), mantle-transparent paralarvae feeding on 18 types of live zooplanktonic prey. We show for the first time in a live cephalopod that octopus paralarvae attack, immobilize, drill, and ingest live cladocerans and copepods with 100% efficiency, which decreases dramatically to 60% on decapod prey (Pisidia longicornis). The majority (85%) of successful attacks targeted the prey cephalothorax while unsuccessful attacks either targeted the dorsal cephalothorax or involved prey defensive strategies (e.g., juvenile crab megalopae) or prey protected by thick carapaces (e.g., gammaridae amphipods). After immobilization, the beak, the buccal mass and the radula were involved in exoskeleton penetration and content ingestion. Ingestion time of prey content was rapid for copepods and cladocerans (73.13 ± 23.34 s) but much slower for decapod zoeae and euphausiids (152.49 ± 29.40 s). Total contact time with prey was always <5 min. Contrary to the conventional view of crop filling dynamics observed in adult O. vulgaris, food accumulated first in the stomach of paralarvae and the crop filled after the stomach volume plateaued. Peristaltic crop contractions (~18/min) moved food into the stomach (contractions ~30/min) from where it passed to the caecum. Pigmented food particles were seen to enter the digestive gland, 312 ± 32 s after the crop reached its maximum volume. Digestive tract contents passed into the terminal intestine by peristalsis (contraction frequency ~50/min) and defaecation was accompanied by an increased frequency

  14. Prey Capture, Ingestion, and Digestion Dynamics of Octopus vulgaris Paralarvae Fed Live Zooplankton

    PubMed Central

    Nande, Manuel; Presa, Pablo; Roura, Álvaro; Andrews, Paul L. R.; Pérez, Montse

    2017-01-01

    Octopus vulgaris is a species of great interest in research areas such as neurobiology, ethology, and ecology but also a candidate species for aquaculture as a food resource and for alleviating the fishing pressure on its wild populations. This study aimed to characterize the predatory behavior of O. vulgaris paralarvae and to quantify their digestive activity. Those processes were affordable using the video-recording analysis of 3 days post-hatching (dph), mantle-transparent paralarvae feeding on 18 types of live zooplanktonic prey. We show for the first time in a live cephalopod that octopus paralarvae attack, immobilize, drill, and ingest live cladocerans and copepods with 100% efficiency, which decreases dramatically to 60% on decapod prey (Pisidia longicornis). The majority (85%) of successful attacks targeted the prey cephalothorax while unsuccessful attacks either targeted the dorsal cephalothorax or involved prey defensive strategies (e.g., juvenile crab megalopae) or prey protected by thick carapaces (e.g., gammaridae amphipods). After immobilization, the beak, the buccal mass and the radula were involved in exoskeleton penetration and content ingestion. Ingestion time of prey content was rapid for copepods and cladocerans (73.13 ± 23.34 s) but much slower for decapod zoeae and euphausiids (152.49 ± 29.40 s). Total contact time with prey was always <5 min. Contrary to the conventional view of crop filling dynamics observed in adult O. vulgaris, food accumulated first in the stomach of paralarvae and the crop filled after the stomach volume plateaued. Peristaltic crop contractions (~18/min) moved food into the stomach (contractions ~30/min) from where it passed to the caecum. Pigmented food particles were seen to enter the digestive gland, 312 ± 32 s after the crop reached its maximum volume. Digestive tract contents passed into the terminal intestine by peristalsis (contraction frequency ~50/min) and defaecation was accompanied by an increased frequency

  15. Steady-state kinetics and chemical mechanism of octopus hepatopancreatic glutathione transferase.

    PubMed Central

    Tang, S S; Chang, G G

    1995-01-01

    The kinetic mechanism of glutathione S-transferase (GST) from Octopus vulgaris hepatopancreas was investigated by steady-state analysis. Initial-velocity studies showed an intersecting pattern, which suggests a sequential kinetic mechanism for the enzyme. Product-inhibition patterns by chloride and the conjugate product were all non-competitive with respect to glutathione or 1-chloro-2,4-dinitrobenzene (CDNB), which indicates that the octopus digestive gland GST conforms to a steady-state sequential random Bi Bi kinetic mechanism. Dead-end inhibition patterns indicate that ethacrynic acid ([2,3-dichloro-4-(2-methyl-enebutyryl) phenoxy]acetic acid) binds at the hydrophobic H-site, norophthalmic acid (gamma-glutamylalanylglycine) binds at the glutathione G-site, and glutathione-ethacrynate conjugate occupied both H- and G-sites of the enzyme. The chemical mechanism of the enzyme was examined by pH and kinetic solvent-isotope effects. At pH (and p2H) = 8.011, in which kcat. was independent of pH or p2H, the solvent isotope effects on V and V/KmGSH were near unity, in the range 1.069-1.175. An inverse isotope effect was observed for V/KmCDNB (0.597), presumably resulting from the hydrogen-bonding of enzyme-bound glutathione, which has pKa of 6.83 +/- 0.04, a value lower by 2.34 pH units than the pKa of glutathione in aqueous solution. This lowering of the pKa value for the sulphydryl group of the bound glutathione was presumably due to interaction with the active site Tyr7, which had a pKa value of 8.46 +/- 0.09 that was raised to 9.63 +/- 0.08 in the presence of glutathione thiolate. Subsequent chemical reaction involves attacking of thiolate anion at the electrophilic substrate with the formation of a negatively charged Meisenheimer complex, which is the rate-limiting step of the reaction. Images Scheme 2 PMID:7619078

  16. Steady-state kinetics and chemical mechanism of octopus hepatopancreatic glutathione transferase.

    PubMed

    Tang, S S; Chang, G G

    1995-07-01

    The kinetic mechanism of glutathione S-transferase (GST) from Octopus vulgaris hepatopancreas was investigated by steady-state analysis. Initial-velocity studies showed an intersecting pattern, which suggests a sequential kinetic mechanism for the enzyme. Product-inhibition patterns by chloride and the conjugate product were all non-competitive with respect to glutathione or 1-chloro-2,4-dinitrobenzene (CDNB), which indicates that the octopus digestive gland GST conforms to a steady-state sequential random Bi Bi kinetic mechanism. Dead-end inhibition patterns indicate that ethacrynic acid ([2,3-dichloro-4-(2-methyl-enebutyryl) phenoxy]acetic acid) binds at the hydrophobic H-site, norophthalmic acid (gamma-glutamylalanylglycine) binds at the glutathione G-site, and glutathione-ethacrynate conjugate occupied both H- and G-sites of the enzyme. The chemical mechanism of the enzyme was examined by pH and kinetic solvent-isotope effects. At pH (and p2H) = 8.011, in which kcat. was independent of pH or p2H, the solvent isotope effects on V and V/KmGSH were near unity, in the range 1.069-1.175. An inverse isotope effect was observed for V/KmCDNB (0.597), presumably resulting from the hydrogen-bonding of enzyme-bound glutathione, which has pKa of 6.83 +/- 0.04, a value lower by 2.34 pH units than the pKa of glutathione in aqueous solution. This lowering of the pKa value for the sulphydryl group of the bound glutathione was presumably due to interaction with the active site Tyr7, which had a pKa value of 8.46 +/- 0.09 that was raised to 9.63 +/- 0.08 in the presence of glutathione thiolate. Subsequent chemical reaction involves attacking of thiolate anion at the electrophilic substrate with the formation of a negatively charged Meisenheimer complex, which is the rate-limiting step of the reaction.

  17. Can Fishing Pressure Invert the Outcome of Interspecific Competition? The Case of the Thiof and of the Octopus Along the Senegalese Coast.

    PubMed

    Nguyen-Phuong, Thuy; Nguyen-Ngoc, Doanh; Auger, Pierre; Ly, Sidy; Jouffre, Didier

    2016-12-01

    We present a mathematical model of two competing marine species that are harvested. We consider three models according to different levels of complexity, without and with species refuge and density-independent and density-dependent species movement between fishing area and refuge. We particularly study the effects of the fishing pressure on the outcome of the competition. We focus on conditions that allow an inferior competitor to invade as a result of fishing pressure. The model is discussed in relationship to the case of the thiof and the octopus along the Atlantic West African coast. At the origin, the thiof was abundant and the octopus scarce in that region. Since, the fishing pressure has strongly increased in some fishing areas leading to the depletion of the thiof and the invasion of its competitor, the octopus.

  18. Ultra-fast escape maneuver of an octopus-inspired robot.

    PubMed

    Weymouth, G D; Subramaniam, V; Triantafyllou, M S

    2015-02-02

    We design and test an octopus-inspired flexible hull robot that demonstrates outstanding fast-starting performance. The robot is hyper-inflated with water, and then rapidly deflates to expel the fluid so as to power the escape maneuver. Using this robot we verify for the first time in laboratory testing that rapid size-change can substantially reduce separation in bluff bodies traveling several body lengths, and recover fluid energy which can be employed to improve the propulsive performance. The robot is found to experience speeds over ten body lengths per second, exceeding that of a similarly propelled optimally streamlined rigid rocket. The peak net thrust force on the robot is more than 2.6 times that on an optimal rigid body performing the same maneuver, experimentally demonstrating large energy recovery and enabling acceleration greater than 14 body lengths per second squared. Finally, over 53% of the available energy is converted into payload kinetic energy, a performance that exceeds the estimated energy conversion efficiency of fast-starting fish. The Reynolds number based on final speed and robot length is [Formula: see text]. We use the experimental data to establish a fundamental deflation scaling parameter [Formula: see text] which characterizes the mechanisms of flow control via shape change. Based on this scaling parameter, we find that the fast-starting performance improves with increasing size.

  19. An octopus toxin, maculotoxin, selectively blocks sodium current in squid axons.

    PubMed

    Gage, P W; Moore, J W; Westerfield, M

    1976-07-01

    1. A low molecular weight, stable, cationic neurotoxin (maculotoxin, MTX) extracted from the posterior salivary glands of the octopus Hapalochlaena maculosa, blocked sodium current in voltage-clamped squid axons without affecting potassium current. 2. The effectiveness of MTX was increased by repetitive, brief, depolarizing pulses but not by a single prolonged depolarization. 3. The potency of MTX decreased at pHs from 8 to 9. Effectiveness could be restored be restored by lowering the pH to 7-1 again. It was concluded that MTX is active in its cationic form. 4. MTX affected sodium conductance kinetics, slowing the turn-on of sodium current. This effect was most noticeable with small deploarizations but became progressively less with larger depolarizations. Neither the turn-off of sodium current nor sodium inactivation kinetics were affected by the toxin. 5. MTX inhibited sodium current without inhibiting sodium gating current. 6. The effectiveness of MTX was not detectably changed when calcium concentration was varied from 50 to 10 mM, or sodium concentration was varied from 225 to 750 mM.

  20. OCTOPUS Negatively Regulates BIN2 to Control Phloem Differentiation in Arabidopsis thaliana.

    PubMed

    Anne, Pauline; Azzopardi, Marianne; Gissot, Lionel; Beaubiat, Sébastien; Hématy, Kian; Palauqui, Jean-Christophe

    2015-10-05

    The phloem is a vascular strand that conducts photoassimilates and systemic signals throughout the plant to coordinate growth. To date, few molecular genetic determinants have been identified to control both specification and differentiation of this tissue [1-3]. Among them, OCTOPUS (OPS) protein was previously identified as a polarly localized plasma membrane-associated protein of unknown biochemical function whose broad provascular expression becomes restricted to the phloem upon differentiation [2]. OPS loss-of-function mutants showed an altered vascular network in cotyledons and an intermittent phloem differentiation in the root [2, 4]. Here, we demonstrate a role for OPS as a positive regulator of the brassinosteroid (BR) signaling pathway. Indeed, transgenic lines overexpressing OPS (OPS-OE) display the hallmarks of constitutively overactivated BR mutants. Physiological and genetic analyses place OPS as a positive regulator of the BR signaling pathway upstream of the key transcription factors BES1 and BZR1. Directed protein interactions with known BR signaling proteins identified BIN2, a GSK3 protein involved in multiple signaling pathways, as a partner of OPS. This interaction recruits BIN2 to the plasma membrane, thus preventing its inhibitory activity in the nucleus. Finally, both bikinin (a potent inhibitor of GSK3 [5]) treatment and downstream dominant mutants bes1-D [6] and bzr1-D [7] can rescue phloem defects of ops in the root. Together, our data show that OPS antagonizes BIN2 to promote phloem differentiation.

  1. The ultrastructure of the spermatozoon of Octopus ocellatus Gray, 1849 (Cephalopoda: Octopoda)

    NASA Astrophysics Data System (ADS)

    Yang, Jianmin; Wang, Weijun; Zheng, Xiaodong; Zhou, Quanli; Zhang, Yu; Sun, Guohua; Liu, Xiangquan

    2011-01-01

    Morphology of the spermatozoon of Octopus ocellatus was studied by light, scanning electron, and transmission electron microscopes. Sperm are 600-700 μm long, with a large number of granules in diameter about 130 nm. Each spermatozoon is composed of a head, neck, and tail. The head is made up of an acrosomal complex anterior to the nucleus. The spiral acrosomal complex consists of an electron-lucent vesicle, lacuna, and an electron-dense acrosomal vesicle. Additionally, the spiral acrosomal vesicle has numerous equidistant striations, and is surrounded by many small granules (20 nm diameter). A long straight nucleus, which is electron-densed, has a deep posterior concavity, the nuclear vacuole. At the terminal end of the nucleus is a sleeve-like structure with a concave posterior nuclear fossa (PNF). The neck is short connecting the PNF. The basal body is located in the PNF and gives rise to the axoneme. This structure connects the head, neck, and tail. The tail is divided into a middle piece and a principal piece. The middle piece, having a 9+9+2 arrangement, is surrounded by a mitochondrial sheath and terminates by an electron-dense fibrous sheath. The principal piece is the longest part of the sperm with coarse fibers tapering posteriorly. The results of this study shall provide some useful information for artificial breeding of this species.

  2. On gonadic maturation and reproductive strategy in deep-sea benthic octopus Graneledone macrotyla

    NASA Astrophysics Data System (ADS)

    Guerra, Ángel; Sieiro, María Pilar; Roura, Álvaro; Portela, Julio M.; del Río, José Luís

    2013-09-01

    The new information reported in this paper is based on five maturing and mature females of the large-tuberculate octopus Graneledone macrotyla. These specimens were caught in bottom trawl surveys ATLANTIS 2009 (February 24 to April 1, 2009) and ATLANTIS 2010 (March 9 to April 5, 2010) carried out off the Argentinean Economic Exclusive Zone. Capture depth ranged from 475 to 921 m and sea bottom temperature between 2.8 and 3.1 °C. Development of the complex ovary, oviducts, and oviducal glands during gonadic maturation is described. The absence of spermathecae in the oviducal glands and the presence of fertilized eggs inside the ovary suggested that fertilization took place within the ovary. Histological techniques showed the presence of four types of oocytes. Maturing oocyte size-frequency distribution was polymodal. Fluorescence reaction showed that atresia occurred in both early and later oocyte maturation stages. Atresia affected 48-55 % of the initial number of oocytes. The maximum observed potential fecundity was estimated at 250-300 eggs. G. macrotyla showed a group-synchronous ovulation pattern, regulative atresia, and a batching spawning pattern with a few egg batches spawned intermittently over an extended period of spawning.

  3. Dynamics of underwater legged locomotion: modeling and experiments on an octopus-inspired robot.

    PubMed

    Calisti, M; Corucci, F; Arienti, A; Laschi, C

    2015-07-30

    This paper studies underwater legged locomotion (ULL) by means of a robotic octopus-inspired prototype and its associated model. Two different types of propulsive actions are embedded into the robot model: reaction forces due to leg contact with the ground and hydrodynamic forces such as the drag arising from the sculling motion of the legs. Dynamic parameters of the model are estimated by means of evolutionary techniques and subsequently the model is exploited to highlight some distinctive features of ULL. Specifically, the separation between the center of buoyancy (CoB)/center of mass and density affect the stability and speed of the robot, whereas the sculling movements contribute to propelling the robot even when its legs are detached from the ground. The relevance of these effects is demonstrated through robotic experiments and model simulations; moreover, by slightly changing the position of the CoB in the presence of the same feed-forward activation, a number of different behaviors (i.e. forward and backward locomotion at different speeds) are achieved.

  4. Morphologic characterisation and elemental distribution of Octopus vulgaris Cuvier, 1797 vestigial shell

    NASA Astrophysics Data System (ADS)

    Napoleão, P.; Reis, C. Sousa; Alves, L. C.; Pinheiro, T.

    2005-04-01

    The elemental composition of mineral structures in marine organisms can provide useful information to reconstruct environmental histories of individuals and distinguish populations or stocks. In cephalopods, as Octopus vulgaris, morpho-physiological description of vestigial shells may contribute to a better understanding of the physiology, of the process involved in the increment growth and may eventually provide important and useful tools for the validation of age determination methods. Nuclear microprobe analysis was used to map chemical elements in O. vulgaris vestigial shell. The maps contain elemental and morphological information, and enabled especially through Cl and Ca distributions to classify bands of concentric rings. The levels of P, Ca and Sr decrease from central region to external rings, while those of S and Cl showed an inverse tendency. Enhanced concentrations of Fe, Cu and Zn were found in external rings, and no significant variations were detected in the K and Br contents. The results indicate that three regions can be established on the basis of the elemental contents distributions. Specially, the P and Ca variability can distinguish rings from central and external regions. The differential incorporation of elements in the vestigial shell observed may reflect environmental and physiological factors that are affecting the life cycle of this species.

  5. An eco-friendly approach for heavy metal adsorbent regeneration using CO2-responsive molecular octopus.

    PubMed

    Bai, Yu; Liang, Yen Nan; Hu, Xiao

    2017-10-01

    Perennial problems of adsorption in wastewater treatment include adsorbent recycling, generation of waste sludge and secondary pollution because harmful concentrated acids, bases or strong chelators are often used for adsorbent regeneration and adsorbate recovery. We report, for the first time, an eco-friendly regeneration concept demonstrated with a CO2-responsive octopus-like polymeric adsorbent. Various heavy metals can be scavenged at very high Qe by such adsorbent through coordination. Most importantly, the rapid and complete regeneration of the adsorbent and recovery of the heavy metal ions can be readily achieved by CO2 bubbling within a few minutes under mild conditions, i.e., room temperature and atmospheric pressure. The adsorbent can then be restored to its adsorptive state and reused upon removal of CO2 by simply bubbling another gas. This eco-friendly, effective, ultra-fast and repeatable CO2-triggered regeneration process using CO2-responsive adsorbent with versatile structure, morphology or form can be incorporated into a sustainable closed-loop wastewater treatment process to solve the perennial problems. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Temperature affects voltage-sensitive conductances differentially in octopus cells of the mammalian cochlear nucleus.

    PubMed

    Cao, Xiao-Jie; Oertel, Donata

    2005-07-01

    Temperature is an important physiological variable the influence of which on macroscopic electrophysiological measurements in slices is not well documented. We show that each of three voltage-sensitive conductances of octopus cells of the mammalian ventral cochlear nucleus (VCN) is affected differently by changes in temperature. As expected, the kinetics of the currents were faster at higher than at lower temperature. Where they could be measured, time constants of activation, deactivation, and inactivation had Q10 values between 1.8 and 4.6. The magnitude of the peak conductances was differentially affected by temperature. While the peak magnitude of the high-voltage-activated K+ conductance, g(KH), was unaffected by changes in temperature, the peak of the low-voltage-activated K+ conductance, g(KL), was reduced by half when the temperature was lowered from 33 to 23 degrees C (Q10 = 2). Changing the temperature changed the kinetics and the magnitude of the hyperpolarization-activated mixed cation conductance, g(h), but the changes in magnitude were transient. The voltage sensitivity of the three conductances was unaffected by temperature. The action of temperature on these conductances is reflected in the resting potentials and in the shapes of action potentials.

  7. Electron-microscopic observations of the gravity receptor epithelia of normal and spinner juvenile Octopus maya.

    PubMed

    Fermin, C D; Colmers, W F; Igarashi, M

    1985-01-01

    Light and electron microscopy of the gravity receptor epithelia (maculae) of statocysts of normal and "spinner" juvenile Octopus maya showed differences between the structures of the hair cells, supporting cells, and afferent neurons of these cephalopods. The maculae of spinner animals were approximately 30% smaller in their surface area and had 40% fewer hair cells. Moreover, the average distance between randomly-chosen hair bundles in scanning electron micrographs of maculae of normal animals was significantly greater (4.33 +/- 6.47 microns) than those of maculae of spinner animals (3.38 +/- 4.90 microns; P less than 0.0001). The sectional area of the supporting cell's microvilli in spinner maculae was larger (0.16 +/- 0.18 microns) than those of normal (0.10 +/- 0.10 micron; P less than 0.0001) O. maya. The morphological differences observed between certain structural components of the maculae of normal and spinner O. maya may be related to the absence and/or malformation of the neuroepithelial suprastructures in spinners. This may have direct or indirect effects to their inability to orient to gravity with these organs.

  8. The relationship between structure and function as measured by OCT and Octopus perimetry.

    PubMed

    Monsalve, Blanca; Ferreras, Antonio; Khawaja, Anthony P; Calvo, Pilar; Ara, Mirian; Fogagnolo, Paolo; Iester, Michele

    2015-09-01

    To determine the structure-function relationship between equivalent visual field areas obtained with the Octopus perimeter (OP), and the peripapillary retinal nerve fibre layer (RNFL) thickness measured with spectral-domain optical coherence tomography (OCT) in healthy individuals and patients with glaucomatous optic neuropathy. Eighty-eight normal subjects and 150 patients with open-angle glaucoma were prospectively recruited. Eligible participants for the glaucoma group were required to have elevated intraocular pressure and glaucomatous optic nerve head morphology. All participants underwent reliable automated perimetry with OP, and optic nerve head imaging with the Cirrus OCT. Principal component analysis of the mean threshold values for the visual field test points were performed independently for each hemifield. Pearson correlations were calculated between visual field regions and RNFL thickness sectors. Mild to moderate correlations were observed between the visual field regions and the peripapillary RNFL thicknesses. Each visual field region was significantly correlated with more than one RNFL sector, and vice versa. The strongest correlation was observed between the RNFL thickness at 5 and 7 clock-hour positions and the superonasal region of OP (r=0.63). Retinal sensitivity evaluated with OP correlated moderately well with the RNFL thickness measured by OCT. There was an overlap of the visual field regions within the optic disc. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  9. Arrangement of subunits and domains within the Octopus dofleini hemocyanin molecule.

    PubMed

    Miller, K I; Schabtach, E; van Holde, K E

    1990-02-01

    Native Octopus dofleini hemocyanin appears as a hollow cylinder in the electron microscope. It is composed of 10 polypeptide subunits, each folded into seven globular oxygen-binding domains. The native structure reassociates spontaneously from subunits in the presence of Mg2+ ions. We have selectively removed the C-terminal domain and purified the resulting six-domain subunits. Although these six-domain subunits do not associate efficiently at pH 7.2, they undergo nearly complete reassociation at pH 8.0. The resulting molecule looks like the native cylindrical whole molecule but lacks the usual fivefold protrusions into the central cavity. Partially reassociated mixtures show dimers of the subunit that have a characteristic parallelogram shape when lying flat on the electron microscope grid, and a "boat" form in side view. Removal of the C-terminal domain from monomers results in the removal of two characteristically placed domains in the dimers. These observations allow the development of a model for the arrangement of the subunits within the whole molecule. The model predicts exactly the views seen in the electron microscope of both whole molecule and dimeric intermediates.

  10. Chromatin organization during spermiogenesis in Octopus vulgaris. II: DNA-interacting proteins.

    PubMed

    Giménez-Bonafé, Pepita; Soler, Fina Martínez; Buesa, Carlos; Sautière, Pierre-Eric; Ausió, Juan; Kouach, Mostafa; Kasinsky, Harold E; Chiva, Manel

    2004-06-01

    In this article we study the proteins responsible for chromatin condensation during spermiogenesis in the cephalopod Octopus vulgaris. The DNA of ripe sperm nuclei in this species is condensed by a set of five different proteins. Four of these proteins are protamines. The main protamine (Po2), a protein of 44 amino acid residues, is extraordinarily simple (composed of only three different amino acid types: arginine (R), serine (S), and glycine (G). It is a basic molecule consisting of 79.5 mol% arginine residues. The rest of the protamines (Po3, Po4, Po5) are smaller molecules (33, 28, and 30 amino acid residues, respectively) that are homologous among themselves and probably with the main Po2 protamine. The ripe sperm nucleus of O. vulgaris also contains a small quantity of a molecule (Po1) that is similar to Po2 protamine. This protein could represent a Po2 protamine-precursor in a very advanced step of its processing. We discuss the characteristics of these proteins, as well as the relation between the complexity of chromatin condensation and the transitions of nuclear proteins during spermiogenesis in O. vulgaris. Copyright 2004 Wiley-Liss, Inc.

  11. Arrangement of subunits and domains within the Octopus dofleini hemocyanin molecule.

    PubMed Central

    Miller, K I; Schabtach, E; van Holde, K E

    1990-01-01

    Native Octopus dofleini hemocyanin appears as a hollow cylinder in the electron microscope. It is composed of 10 polypeptide subunits, each folded into seven globular oxygen-binding domains. The native structure reassociates spontaneously from subunits in the presence of Mg2+ ions. We have selectively removed the C-terminal domain and purified the resulting six-domain subunits. Although these six-domain subunits do not associate efficiently at pH 7.2, they undergo nearly complete reassociation at pH 8.0. The resulting molecule looks like the native cylindrical whole molecule but lacks the usual fivefold protrusions into the central cavity. Partially reassociated mixtures show dimers of the subunit that have a characteristic parallelogram shape when lying flat on the electron microscope grid, and a "boat" form in side view. Removal of the C-terminal domain from monomers results in the removal of two characteristically placed domains in the dimers. These observations allow the development of a model for the arrangement of the subunits within the whole molecule. The model predicts exactly the views seen in the electron microscope of both whole molecule and dimeric intermediates. Images PMID:2304914

  12. An investigation of the nature of Bohr, Root, and Haldane effects in Octopus dofleini hemocyanin.

    PubMed

    Miller, K I; Mangum, C P

    1988-01-01

    1. The pH dependence of Octopus dofleini hemocyanin oxygenation is so great that below pH 7.0 the molecule does not become fully oxygenated, even in pure O2 at 1 atm pressure. However, the curves describing percent oxygenation as a function of PO2 appear to be gradually increasing in oxygen saturation, rather than leveling out at less than full saturation. Hill plots indicate that at pH 6.6 and below the molecule is stabilized in its low affinity conformation. Thus, the low saturation of this hemocyanin in air is due to the very large Bohr shift, and not to the disabling of one or more functionally distinct O2 binding sites on the native molecule. 2. Experiments in which pH was monitored continuously while oxygenation was manipulated in the presence of CO2 provide no evidence of O2 linked binding of CO2. While CO2 does influence O2 affinity independently of pH, its effect may be due to high levels of HCO3- and CO3-, rather than molecular CO2, and it may entail a lowering of the activities of the allosteric effectors Mg2+ and Ca2+.

  13. Phosphosite charge rather than shootward localization determines OCTOPUS activity in root protophloem.

    PubMed

    Breda, Alice S; Hazak, Ora; Hardtke, Christian S

    2017-07-11

    Polar cellular localization of proteins is often associated with their function and activity. In plants, relatively few polar-localized factors have been described. Among them, the plasma membrane-associated Arabidopsis proteins OCTOPUS (OPS) and BREVIS RADIX (BRX) display shootward and rootward polar localization, respectively, in developing root protophloem cells. Both ops and brx null mutants exhibit defects in protophloem differentiation. Here we show that OPS and BRX act genetically in parallel in this process, although OPS dosage increase mends defects caused by brx loss-of-function. OPS protein function is ancient and conserved in the most basal angiosperms; however, many highly conserved structural OPS features are not strictly required for OPS function. They include a BRASSINOSTEROID INSENSITIVE 2 (BIN2) interaction domain, which supposedly mediates gain-of-function effects obtained through ectopic OPS overexpression. However, engineering an increasingly positive charge in a critical phosphorylation site, S318, progressively amplifies OPS activity. Such hyperactive OPS versions can even complement the severe phenotype of brx ops double mutants, and the most active variants eventually trigger gain-of-function phenotypes. Finally, BRX-OPS as well as OPS-BRX fusion proteins localize to the rootward end of developing protophloem cells, but complement ops mutants as efficiently as shootward localized OPS. Thus, our results suggest that S318 phosphorylation status, rather than a predominantly shootward polar localization, is a primary determinant of OPS activity.

  14. Role of the tertiary structure in the diphenol oxidase activity of Octopus vulgaris hemocyanin.

    PubMed

    Campello, S; Beltramini, M; Giordano, G; Di Muro, P; Marino, S M; Bubacco, L

    2008-03-15

    The functional differences between the oxygen transport protein Hemocyanin and the enzymes Tyrosinase and Catechol oxidase are believed to be governed, at least in part, by the tertiary structure, which differs in these molecules and controls the accessibility of their copper containing active site for substrate(s). Accordingly, Octopus vulgaris Hemocyanin catalyses the o-diphenol oxidation to o-quinone at a very low rate. The crystallographic structure of one of the functional units (called Odg) of O. dofleini Hemocyanin shows two domains, a mainly alpha-helical domain that directly binds the copper ions of the reaction center and a beta-strand domain that precludes access to the active site to ligands bigger than molecular oxygen. In this work, we have first cleaved the whole protein and then purified different oxygen binding functional units from O. vulgaris Hemocyanin. These functional units were used in activity assays with l-DOPA, the paradigmatic substrate for Catechol oxidase. All functional units show a negligible enzymatic activity. The procedure to generate the functional units induces in only one of them a proteolytic cleavage. Amino terminal sequencing and mass spectroscopy of the fragments allow to place the cleavage site between the alpha and beta domains of the functional unit homologous to Odd, in the O. dofleini sequence. An increase, up to three orders of magnitude, of Tyrosinase-like activity was observed when the cleaved Odd-like was incubated with the substrate in the presence of trifluoroethanol or hexafluoroisopropanol.

  15. Phylogenetic analysis of the hyperthermophilic pink filament community in Octopus Spring, Yellowstone National Park.

    PubMed Central

    Reysenbach, A L; Wickham, G S; Pace, N R

    1994-01-01

    The phylogenetic diversity of a well-known pink filament community associated with the 84 to 88 degrees C outflow from Octopus Spring, Yellowstone National Park, was examined. Three phylogenetic types ("phylotypes"), designated EM 3, EM 17, and EM 19, were identified by cloning and sequencing the small subunit rRNA genes (16S rDNA) obtained by PCR amplification of mixed-population DNA. All three phylotypes diverge deeply within the phylogenetic domain Bacteria sensu Woese (C. R. Woese, O. Kandler, and M. L. Wheelis, Proc. Natl. Acad. Sci. USA 87:4576-4579, 1990). No members of the Archaea or Eucarya were detected. EM 3 comprises a unique lineage within the Thermotogales group, and EM 17 and EM 19 are affiliated with the Aquificales. A total of 35 clones were examined, of which the majority (26 clones) were of a single sequence type (EM 17) closely related to Aquifex pyrophilus. In situ hybridization with clone-specific probes attributes the majority sequence, EM 17, to the pink filaments. Images PMID:7518219

  16. Octopus: a platform for the virtual high-throughput screening of a pool of compounds against a set of molecular targets.

    PubMed

    Maia, Eduardo Habib Bechelane; Campos, Vinícius Alves; Dos Reis Santos, Bianca; Costa, Marina Santos; Lima, Iann Gabriel; Greco, Sandro J; Ribeiro, Rosy I M A; Munayer, Felipe M; da Silva, Alisson Marques; Taranto, Alex Gutterres

    2017-01-01

    Octopus is an automated workflow management tool that is scalable for virtual high-throughput screening (vHTS). It integrates MOPAC2016, MGLTools, PyMOL, and AutoDock Vina. In contrast to other platforms, Octopus can perform docking simulations of an unlimited number of compounds into a set of molecular targets. After generating the ligands in a drawing package in the Protein Data Bank (PDB) format, Octopus can carry out geometry refinement using the semi-empirical method PM7 implemented in MOPAC2016. Docking simulations can be performed using AutoDock Vina and can utilize the Our Own Molecular Targets (OOMT) databank. Finally, the proposed software compiles the best binding energies into a standard table. Here, we describe two successful case studies that were verified by biological assay. In the first case study, the vHTS process was carried out for 22 (phenylamino)urea derivatives. The vHTS process identified a metalloprotease with the PDB code 1GKC as a molecular target for derivative LE&007. In a biological assay, compound LE&007 was found to inhibit 80% of the activity of this enzyme. In the second case study, compound Tx001 was submitted to the Octopus routine, and the results suggested that Plasmodium falciparum ATP6 (PfATP6) as a molecular target for this compound. Following an antimalarial assay, Tx001 was found to have an inhibitory concentration (IC50) of 8.2 μM against PfATP6. These successful examples illustrate the utility of this software for finding appropriate molecular targets for compounds. Hits can then be identified and optimized as new antineoplastic and antimalarial drugs. Finally, Octopus has a friendly Linux-based user interface, and is available at www.drugdiscovery.com.br . Graphical Abstract Octopus: A platform for inverse virtual screening (IVS) to search new molecular targets for drugs.

  17. First visualization of cholinergic cells and fibers by immunohistochemistry for choline acetyltransferase of the common type in the optic lobe and peduncle complex of Octopus vulgaris.

    PubMed

    D'Este, Loredana; Kimura, Shin; Casini, Arianna; Matsuo, Akinori; Bellier, Jean-Pierre; Kimura, Hiroshi; Renda, Tindaro G

    2008-08-20

    This study provides the first immunohistochemical evidence visualizing cholinergic octopus neurons containing choline acetyltransferase (ChAT), the synthetic enzyme of acetylcholine. Because the antiserum applied here was raised against a recombinant protein encoded by exons 7 and 8 of the rat gene for ChAT, and initially used for studies in mammals, to validate antibody specificity for the octopus counterpart enzyme we therefore used three methods. Immunoprecipitation using Pansorbin indicated that immunoreactive octopus brain molecules were capable of synthesizing acetylcholine. Western blot analysis after denatured gel electrophoresis of octopus brain extracts revealed a single band at approximately 81 kDa. A gel slice containing the 81-kDa protein after native (nondenatured) gel electrophoresis exhibited high ChAT activity. All findings obtained with these three methods clearly indicated that the antiserum effectively recognizes octopus ChAT. The immunohistochemical use of the antiserum in the retina, optic lobe, and its neighboring peduncle complex detected enzyme-containing neuronal cell bodies in only two regions, the cell islands of the optic lobe medulla and the cortical layer of the posterior olfactory lobule. Immunoreactive fibers and probable nerve terminals were also found in the plexiform layer of the deep retina, within the stroma of the optic gland, and the neuropils of the optic lobe, peduncle lobe, and olfactory lobe. These results provide information on the morphology and distribution patterns of cholinergic neurons in the octopus visual system, a useful invertebrate model for learning and memory where the cholinergic system, as in higher vertebrates including mammals, plays an important role. Copyright 2008 Wiley-Liss, Inc.

  18. Positive Catch & Economic Benefits of Periodic Octopus Fishery Closures: Do Effective, Narrowly Targeted Actions 'Catalyze' Broader Management?

    PubMed

    Oliver, Thomas A; Oleson, Kirsten L L; Ratsimbazafy, Hajanaina; Raberinary, Daniel; Benbow, Sophie; Harris, Alasdair

    2015-01-01

    Eight years of octopus fishery records from southwest Madagascar reveal significant positive impacts from 36 periodic closures on: (a) fishery catches and (b) village fishery income, such that (c) economic benefits from increased landings outweigh costs of foregone catch. Closures covered ~20% of a village's fished area and lasted 2-7 months. Octopus landings and catch per unit effort (CPUE) significantly increased in the 30 days following a closure's reopening, relative to the 30 days before a closure (landings: +718%, p<0.0001; CPUE: +87%, p<0.0001; n = 36). Open-access control sites showed no before/after change when they occurred independently of other management ("no ban", n = 17/36). On the other hand, open-access control sites showed modest catch increases when they extended a 6-week seasonal fishery shutdown ("ban", n = 19/36). The seasonal fishery shutdown affects the entire region, so confound all potential control sites. In villages implementing a closure, octopus fishery income doubled in the 30 days after a closure, relative to 30 days before (+132%, p<0.001, n = 28). Control villages not implementing a closure showed no increase in income after "no ban" closures and modest increases after "ban" closures. Villages did not show a significant decline in income during closure events. Landings in closure sites generated more revenue than simulated landings assuming continued open-access fishing at that site (27/36 show positive net earnings; mean +$305/closure; mean +57.7% monthly). Benefits accrued faster than local fishers' time preferences during 17-27 of the 36 closures. High reported rates of illegal fishing during closures correlated with poor economic performance. We discuss the implications of our findings for broader co-management arrangements, particularly for catalyzing more comprehensive management.

  19. Octopus Cells in the Posteroventral Cochlear Nucleus Provide the Main Excitatory Input to the Superior Paraolivary Nucleus.

    PubMed

    Felix Ii, Richard A; Gourévitch, Boris; Gómez-Álvarez, Marcelo; Leijon, Sara C M; Saldaña, Enrique; Magnusson, Anna K

    2017-01-01

    Auditory streaming enables perception and interpretation of complex acoustic environments that contain competing sound sources. At early stages of central processing, sounds are segregated into separate streams representing attributes that later merge into acoustic objects. Streaming of temporal cues is critical for perceiving vocal communication, such as human speech, but our understanding of circuits that underlie this process is lacking, particularly at subcortical levels. The superior paraolivary nucleus (SPON), a prominent group of inhibitory neurons in the mammalian brainstem, has been implicated in processing temporal information needed for the segmentation of ongoing complex sounds into discrete events. The SPON requires temporally precise and robust excitatory input(s) to convey information about the steep rise in sound amplitude that marks the onset of voiced sound elements. Unfortunately, the sources of excitation to the SPON and the impact of these inputs on the behavior of SPON neurons have yet to be resolved. Using anatomical tract tracing and immunohistochemistry, we identified octopus cells in the contralateral cochlear nucleus (CN) as the primary source of excitatory input to the SPON. Cluster analysis of miniature excitatory events also indicated that the majority of SPON neurons receive one type of excitatory input. Precise octopus cell-driven onset spiking coupled with transient offset spiking make SPON responses well-suited to signal transitions in sound energy contained in vocalizations. Targets of octopus cell projections, including the SPON, are strongly implicated in the processing of temporal sound features, which suggests a common pathway that conveys information critical for perception of complex natural sounds.

  20. Vault-poly-ADP-ribose polymerase in the Octopus vulgaris brain: a regulatory factor of actin polymerization dynamic.

    PubMed

    De Maio, Anna; Natale, Emiliana; Rotondo, Sergio; Di Cosmo, Anna; Faraone-Mennella, Maria Rosaria

    2013-09-01

    Our previous behavioural, biochemical and immunohistochemical analyses conducted in selected regions (supra/sub oesophageal masses) of the Octopus vulgaris brain detected a cytoplasmic poly-ADP-ribose polymerase (more than 90% of total enzyme activity). The protein was identified as the vault-free form of vault-poly-ADP-ribose polymerase. The present research extends and integrates the biochemical characterization of poly-ADP-ribosylation system, namely, reaction product, i.e., poly-ADP-ribose, and acceptor proteins, in the O. vulgaris brain. Immunochemical analyses evidenced that the sole poly-ADP-ribose acceptor was the octopus cytoskeleton 50-kDa actin. It was present in both free, endogenously poly-ADP-ribosylated form (70kDa) and in complex with V-poly-ADP-ribose polymerase and poly-ADP-ribose (260kDa). The components of this complex, alkali and high salt sensitive, were purified and characterized. The kind and the length of poly-ADP-ribose corresponded to linear chains of 30-35 ADP-ribose units, in accordance with the features of the polymer synthesized by the known vault-poly-ADP-ribose polymerase. In vitro experiments showed that V-poly-ADP-ribose polymerase activity of brain cytoplasmic fraction containing endogenous actin increased upon the addition of commercial actin and was highly reduced by ATP. Anti-actin immunoblot of the mixture in the presence and absence of ATP showed that the poly-ADP-ribosylation of octopus actin is a dynamic process balanced by the ATP-dependent polymerization of the cytoskeleton protein, a fundamental mechanism for synaptic plasticity.

  1. Octopus Cells in the Posteroventral Cochlear Nucleus Provide the Main Excitatory Input to the Superior Paraolivary Nucleus

    PubMed Central

    Felix II, Richard A.; Gourévitch, Boris; Gómez-Álvarez, Marcelo; Leijon, Sara C. M.; Saldaña, Enrique; Magnusson, Anna K.

    2017-01-01

    Auditory streaming enables perception and interpretation of complex acoustic environments that contain competing sound sources. At early stages of central processing, sounds are segregated into separate streams representing attributes that later merge into acoustic objects. Streaming of temporal cues is critical for perceiving vocal communication, such as human speech, but our understanding of circuits that underlie this process is lacking, particularly at subcortical levels. The superior paraolivary nucleus (SPON), a prominent group of inhibitory neurons in the mammalian brainstem, has been implicated in processing temporal information needed for the segmentation of ongoing complex sounds into discrete events. The SPON requires temporally precise and robust excitatory input(s) to convey information about the steep rise in sound amplitude that marks the onset of voiced sound elements. Unfortunately, the sources of excitation to the SPON and the impact of these inputs on the behavior of SPON neurons have yet to be resolved. Using anatomical tract tracing and immunohistochemistry, we identified octopus cells in the contralateral cochlear nucleus (CN) as the primary source of excitatory input to the SPON. Cluster analysis of miniature excitatory events also indicated that the majority of SPON neurons receive one type of excitatory input. Precise octopus cell-driven onset spiking coupled with transient offset spiking make SPON responses well-suited to signal transitions in sound energy contained in vocalizations. Targets of octopus cell projections, including the SPON, are strongly implicated in the processing of temporal sound features, which suggests a common pathway that conveys information critical for perception of complex natural sounds. PMID:28620283

  2. Structure formation in binary mixtures of surfactants: vesicle opening-up to bicelles and octopus-like micelles

    NASA Astrophysics Data System (ADS)

    Noguchi, Hiroshi

    Micelle formation in binary mixtures of surfactants is studied using a coarse-grained molecular simulation. When a vesicle composed of lipid and detergent types of molecules is ruptured, a disk-shaped micelle, the bicelle, is typically formed. It is found that cup-shaped vesicles and bicelles connected with worm-like micelles are also formed depending on the surfactant ratio and critical micelle concentration. The obtained octopus shape of micelles agree with those observed in the cryo-TEM images reported in [S. Jain and F. S. Bates, Macromol. 37, 1511 (2004).]. Two types of connection structures between the worm-like micelles and the bicelles are revealed.

  3. Metal-catalyzed oxidation and cleavage of octopus glutathione transferase by the Cu(II)-ascorbate system.

    PubMed

    Tang, S S; Lin, C C; Chang, G G

    1996-01-01

    Glutathione transferase (GST) from octopus hepatopancreas was rapidly inactivated by micromolar concentration of Cu(II) in the presence of ascorbate at neutral pH and 0 degree C. Omitting the metal ion or ascorbate, or replacing the Cu(II) with Fe(II) did not result in any inactivation. Glutathione or the conjugation product of glutathione and 1-chloro-2,4-dinitrobenzene offered complete protection of the enzyme from Cu(II)-induced inactivation. 1-Chloro-2,4-dinitrobenzene, however, did not provide any protection. The inactivation was time and Cu(II) concentration dependent. The dependence of inactivation rate on Cu(II) concentration displayed saturation kinetics, which suggests that the inactivation occurs in two steps with Cu(II) binding with the enzyme first (KdCu = 260 microM), then the locally generated free radicals modify the essential amino acid residues in the active center, which results in enzyme inactivation. The Cu(II)-ascorbate system is, thus, an affinity reagent for the octopus GST. The enzyme inactivation was demonstrated to be followed by protein cleavage. Native octopus GST has a subunit M(r) of 24,000. The inactivated enzyme was cleaved at the C-terminal domain (domain II) of the enzyme molecule and resulted in the formation of peptide fragment of M(r) 15,300, which has the identical N-terminal amino acid sequence as the native enzyme. The other half of the peptide with M(r) approximately 7700 was visible in the gels only after silver staining, which also revealed a minor cleavage site, also located at the domain II, to produce peptide fragments of M(r) approximately 11,300 and 8300. The oxygen carrier molecule in the cephalopods' blood is the copper-containing hemocyanin, which during turnover will release Cu(II). Our results indicate that Cu(II) catalyzes a site-specific oxidation of the essential amino acid residues at the C-terminus of GST causing enzyme inactivation. The modified-enzyme is then affinity cleaved at the putative metal binding

  4. Rapid method for controlling the correct labeling of products containing common octopus (Octopus vulgaris) and main substitute species (Eledone cirrhosa and Dosidicus gigas) by fast real-time PCR.

    PubMed

    Espiñeira, Montserrat; Vieites, Juan M

    2012-12-15

    The TaqMan real-time PCR has the highest potential for automation, therefore representing the currently most suitable method for screening, allowing the detection of fraudulent or unintentional mislabeling of species. This work describes the development of a real-time polymerase chain reaction (RT-PCR) system for the detection and identification of common octopus (Octopus vulgaris) and main substitute species (Eledone cirrhosa and Dosidicus gigas). This technique is notable for the combination of simplicity, speed, sensitivity and specificity in an homogeneous assay. The method can be applied to all kinds of products; fresh, frozen and processed, including those undergoing intensive processes of transformation. This methodology was validated to check how the degree of food processing affects the method and the detection of each species. Moreover, it was applied to 34 commercial samples to evaluate the labeling of products made from them. The methodology herein developed is useful to check the fulfillment of labeling regulations for seafood products and to verify traceability in commercial trade and for fisheries control.

  5. Expression analysis of HSP70 in the testis of Octopus tankahkeei under thermal stress.

    PubMed

    Long, Ling-Li; Han, Ying-Li; Sheng, Zhang; Du, Chen; Wang, You-Fa; Zhu, Jun-Quan

    2015-09-01

    The gene encoding heat shock protein 70 (HSP70) was identified in Octopus tankahkeei by homologous cloning and rapid amplification of cDNA ends (RACE). The full-length cDNA (2471 bp) consists of a 5'-untranslated region (UTR) (89 bp), a 3'-UTR (426 bp), and an open reading frame (1956 bp) that encodes 651 amino acid residues with a predicted molecular mass of 71.8 kDa and an isoelectric point of 5.34. Based on the amino acid sequence analysis and multiple sequence alignment, this cDNA is a member of cytoplasmic hsp70 subfamily of the hsp70 family and was designated as ot-hsp70. Tissue expression analysis showed that HSP70 expression is highest in the testes when all examined organs were compared. Immunohistochemistry analysis, together with hematoxylin-eosin staining, revealed that the HSP70 protein was expressed in all spermatogenic cells, but not in fibroblasts. In addition, O. tankahkeei were heat challenged by exposure to 32 °C seawater for 2 h, then returned to 13 °C for various recovery time (0-24 h). Relative expression of ot-hsp70 mRNA in the testes was measured at different time points post-challenge by quantitative real-time PCR. A clear time-dependent mRNA expression of ot-hsp70 after thermal stress indicates that the HSP70 gene is inducible. Ultrastructural changes of the heat-stressed testis were observed by transmission electron microscopy. We suggest that HSP70 plays an important role in spermatogenesis and testis protection against thermal stress in O. tankahkeei.

  6. Retinoid cycling proteins redistribute in light-/dark-adapted octopus retinas.

    PubMed

    Robles, L J; Camacho, J L; Torres, S C; Flores, A; Fariss, R N; Matsumoto, B

    1995-08-07

    In cephalopods, the complex rhodopsin-retinochrome system serves to regenerate metarhodopsin and metaretinochrome after illumination. In the dark, a soluble protein, retinal-binding protein (RALBP), shuttles 11-cis retinal released from metaretinochrome located in the photoreceptor inner segments to metarhodopsin present in the rhabdoms. While in the rhabdoms, RALBP delivers 11-cis retinal to regenerate rhodopsin and in turn binds the all-trans isomer released by metarhodopsin. RALBP then returns all-trans retinal to the inner segments to restore retinochrome. The conventional interpretation of retinoid cycling is contradicted by immunocytochemical studies showing that, in addition to rhodopsin, retinochrome is present in the rhabdomal compartment, making possible the direct exchange of chromophores between the metapigments with the potential exclusion of RALBP. By using immunofluorescence and laser scanning confocal microscopy, we have precisely located opsin, aporetinochrome, and RALBP in light-/dark-adapted octopus retinas. We found differences in the distribution of all three proteins throughout the retina. Most significantly, comparison of cross sections though light- and dark-adapted rhabdoms showed a dramatic shift in position of the proteins. In the dark, opsin and retinochrome colocalized at the base of the rhabdomal microvilli. In the light, opsin redistributed along the length of the microvillar membranes, and retinochrome retreated to a location that is perhaps extracellular. RALBP was present in the core cytoplasm of the photoreceptor outer segments in the dark, and RALBP moved to the periphery in the light. Because of the colocalization of opsin and retinochrome in the dark, we believe that the two metapigments participate directly in chromophore exchange. RALBP may serve to transport additional chromophore from the inner segments to the rhabdoms and may not be immediately involved in the exchange process.

  7. The enzymatic properties of Octopus vulgaris hemocyanin: o-diphenol oxidase activity.

    PubMed

    Salvato, B; Santamaria, M; Beltramini, M; Alzuet, G; Casella, L

    1998-10-06

    Hemocyanin and tyrosinase are dinuclear copper proteins capable of reversibly binding dioxygen. Despite the great similarity of structure and properties of their active site, the two proteins perform different biological functions (oxygen transport/storage versus monooxygenase and oxidase activity). In this paper, we show that Octopus vulgaris hemocyanin exhibits a tyrosinase-like activity; namely, it is capable of utilizing dioxygen for the oxidation of o-diphenol to quinone. The reaction is specific for this isomer of diphenol, the meta and para isomers being unreactive, and is strongly controlled by steric factors. Dioxygen represents a cosubstrate of the reaction, and it is involved in the catalytic turnover by binding to the dinuclear copper site of the protein to form, under steady-state conditions, oxy-Hc, which is the active species. The generation of semiquinone radicals, detected by EPR and by their reaction with N,N,N',N'-tetramethyl-1,4-phenylenediamine, strongly supports a reaction mechanism in which such radicals represent the reaction products of one-electron oxidation of the substrate, quinone being generated by dismutation of semiquinones. Met-Hc is regenerated by the substrate to the deoxy form. To close the catalytic cycle, the proposed reaction mechanism also involves the participation of two transient protein forms with the total oxidation state of the active site (V and IV) intermediate between that of oxy-Hcy, [CuIIO22-CuII]VI, and deoxy-Hc, [CuICuI]II. A mathematical model has been elaborated to describe the reaction kinetics. The differences in reaction mechanisms between hemocyanin and tyrosinase are discussed in terms of accessibility to exogenous molecules of their active sites.

  8. Responses of a thermophilic Synechococcus isolate from the microbial mat of Octopus Spring to light.

    PubMed

    Kilian, Oliver; Steunou, Anne-Soisig; Fazeli, Fariba; Bailey, Shaun; Bhaya, Devaki; Grossman, Arthur R

    2007-07-01

    Thermophilic cyanobacteria of the genus Synechococcus are major contributors to photosynthetic carbon fixation in the photic zone of microbial mats in Octopus Spring, Yellowstone National Park. Synechococcus OS-B' was characterized with regard to the ability to acclimate to a range of different light irradiances; it grows well at 25 to 200 micromol photons m(-2) s(-1) but dies when the irradiance is increased to 400 micromol photons m(-2) s(-1). At 200 micromol photons m(-2) s(-1) (high light [HL]), we noted several responses that had previously been associated with HL acclimation of cyanobacteria, including cell bleaching, reduced levels of phycobilisomes and chlorophyll, and elevated levels of a specific carotenoid. Synechococcus OS-B' synthesizes the carotenoids zeaxanthin and beta,beta-carotene and a novel myxol-anhydrohexoside. Interestingly, 77-K fluorescence emission spectra suggest that Synechococcus OS-B' accumulates very small amounts of photosystem II relative to that of photosystem I. This ratio further decreased at higher growth irradiances, which may reflect potential photodamage following exposure to HL. We also noted that HL caused reduced levels of transcripts encoding phycobilisome components, particularly that for CpcH, a 20.5-kDa rod linker polypeptide. There was enhanced transcript abundance of genes encoding terminal oxidases, superoxide dismutase, tocopherol cyclase, and phytoene desaturase. Genes encoding the photosystem II D1:1 and D1:2 isoforms (psbAI and psbAII/psbAIII, respectively) were also regulated according to the light regimen. The results are discussed in the context of how Synechococcus OS-B' may cope with high light irradiances in the high-temperature environment of the microbial mat.

  9. Presence of two neuropeptides in the fusiform ganglion and reproductive ducts of Octopus vulgaris: FMRFamide and gonadotropin-releasing hormone (GnRH).

    PubMed

    Di Cristo, Carlo; Paolucci, Marina; Iglesias, Josè; Sanchez, Javier; Di Cosmo, Anna

    2002-02-15

    We have found evidence of FMRFamide-like and cGnRH-I-like immunoreactivity in the central nervous system (CNS) and in the reproductive ducts of both female and male cephalopod Octopus vulgaris. Cell bodies and fibers were immunolocalized in the fusiform ganglion from which the nerves that reach the female and male reproductive ducts arise. FMRFamide-like and cGnRH-I-like immunoreactive nerve endings were present in the oviduct, and in the oviducal gland of the female and in the seminal vesicle of the male. The GnRH-like peptide from the reproductive ducts has been partially characterized by HPLC. The retention time of the Octopus vulgaris GnRH-like peptide was similar to the retention time of cGnRH-I. Based on these observations we suggest that FMRFamide-like and a novel GnRH-like peptide are involved in the control of reproductive ducts of Octopus vulgaris. One possibility is that the peptides affect gamete transport. Another possibility is that they regulate secretory products such as mucus and mucilaginous substances from the oviducal gland and the seminal vesicle. Our data provide further evidence to support the hypothesis of the existence of a central and peripheral peptidergic control of reproduction of Octopus vulgaris.

  10. Octopus S-crystallins with endogenous glutathione S-transferase (GST) activity: sequence comparison and evolutionary relationships with authentic GST enzymes.

    PubMed Central

    Chiou, S H; Yu, C W; Lin, C W; Pan, F M; Lu, S F; Lee, H J; Chang, G G

    1995-01-01

    S-Crystallin is a major protein present in the lenses of cephalopods (octopus and squid). To facilitate the cloning of this crystallin gene, cDNA was constructed from the poly(A)+ mRNA of octopus lenses, and amplified by PCR for nucleotide sequencing. Sequencing of 10 of 15 positive clones coding for this crystallin revealed three distinct S-crystallin isoforms with 61-64% identity in nucleotide sequences and 42-58% similarity in amino acid sequences when compared with homologous crystallins in squid lenses. These charge-isomeric crystallins also show between 26 and 33% amino acid sequence identity to four major classes of glutathione S-transferase (GST), a major detoxification enzyme present in most mammalian tissues. For further analysis, expression of one of the S-crystallin cDNAs was carried out in the bacterial expression system pQE-30, and the S-crystallin protein produced in Escherichia coli was purified to homogeneity to determine the enzymic properties. We found that the expressed octopus S-crystallin possessed much lower GST activity than the authentic GSTs from other tissues. Sequence comparison and construction of phylogenetic trees for S-crystallins from squid and octopus lenses and various classes of GSTs revealed that S-crystallins represent a multigene family which is structurally related to Alpha-class GSTs and probably derived from the ancestral GST by gene duplication and subsequent multiple mutational substitutions. Images Figure 2 Figure 3 Figure 6 Figure 7 PMID:7639695

  11. Characterization of proteases from Planomicrobium sp. L-2 isolated from the gastrointestinal tract of Octopus variabilis (Sasaki)

    NASA Astrophysics Data System (ADS)

    Jin, Yulan; Wang, Yurong; Xiao, Lin; Lin, Xiukun

    2016-05-01

    A crude protease produced from Planomicrobium sp. L-2 is described, and its effectiveness as an additive in liquid detergent evaluated. We isolate the protease-producing Planomicrobium sp. L-2 from the gastrointestinal tract of Octopus variabilis. At least three caseinolytic protease clear bands were observed in zymogram analysis. The crude alkaline protease was highly tolerant of a pH range from 7.0 to 9.0, and temperatures to 50°C after incubation for 1 h. Proteolytic enzymes were stable towards three surfactants (5% Tween 80, 1% Triton X-100 and 0.05% SDS) and an oxidizing agent (1% hydrogen peroxide), in addition to being highly stable and compatible with popular commercial laundry powered detergent brands available in China. Our study demonstrates the potential these proteases have for development into novel classes of detergent additive. This study also suggests that the gastrointestinal tract of Octopus variabilis may be a rich source of commercially valuable strains of enzyme.

  12. Origin of the human alcohol dehydrogenase system: implications from the structure and properties of the octopus protein.

    PubMed Central

    Kaiser, R; Fernández, M R; Parés, X; Jörnvall, H

    1993-01-01

    In contrast to the multiplicity of alcohol dehydrogenase in vertebrates, a class III type of the enzyme [i.e., a glutathione-dependent formaldehyde dehydrogenase; formaldehyde; NAD+ oxidoreductase (glutathione-formylating), EC 1.2.1.1.] is the only form detectable in appreciable yield in octopus. It is enzymatically and structurally highly similar to the human class III enzyme, with limited overall residue differences (26%) and only a few conservative residue exchanges at the substrate and coenzyme pockets, reflecting "constant" characteristics of this class over wide time periods. It is distinct from the ethanol-active "variable" class I type of the enzyme (i.e., classical liver alcohol dehydrogenase; alcohol:NAD+ oxidoreductase, EC 1.1.1.1). The residue conservation of class III is also spaced differently from that of class I but is typical of that of proteins in general, emphasizing that class I, with divergence at three functional segments, is the form with deviating properties. In spite of the conservation in class III, surface charges differ considerably. The apparent absence of a class I enzyme in octopus and the constant nature of the class III enzyme support the concept of a duplicative origin of the class I line from the ancient class III form. Still more distant relationships define further enzyme lines that have subunits with other properties. PMID:8248232

  13. Intra-organismal distribution of tetrodotoxin in two species of blue-ringed octopuses (Hapalochlaena fasciata and H. lunulata).

    PubMed

    Williams, Becky L; Caldwell, Roy L

    2009-09-01

    In-depth studies on the intra-organismal distribution of toxin may yield valuable clues about potential ecological functions. The distribution of tetrodotoxin (TTX) in previously unexamined tissues of two species of blue-ringed octopuses, wild-caught Hapalochlaena fasciata and Hapalochlaena lunulata from the aquarium industry, was surveyed. Tissues from each individual were examined separately. Tetrodotoxin was detected in posterior salivary gland (PSG), arm, mantle, anterior salivary glands, digestive gland, testes contents, brachial heart, nephridia, gill, and oviducal gland of H. fasciata. By contrast TTX was found only in the PSG, mantle tissue, and ink of H. lunulata. The highest concentrations of TTX resided in the PSG of both species; however, the arms and mantle contained the greatest absolute amounts of TTX. Minimum total amounts of TTX per octopus ranged from 60 to 405 microg in H. fasciata and from 0 to 174 microg in H. lunulata and correlated well with the amounts in the PSG. Transport of TTX in the blood is loosely suggested by the presence of the toxin in blood-rich organs such as the gill and brachial hearts. The distributional data also suggest both offensive and defensive functions of TTX.

  14. DNA damage and metal accumulation in four tissues of feral Octopus vulgaris from two coastal areas in Portugal.

    PubMed

    Raimundo, Joana; Costa, Pedro M; Vale, Carlos; Costa, Maria Helena; Moura, Isabel

    2010-10-01

    The alkaline comet assay has been employed for the first time to estimate the basal DNA damage in the digestive gland, gills, kidney and gonads of Octopus vulgaris. Octopuses were captured in two coastal areas adjacent to the cities of Matosinhos (N) and Olhão (S), Portugal. The area of Matosinhos is influenced by discharges of the Douro River, city of Porto, industries and intensive agriculture, while Olhão is an important fisheries port. Previous works point to contrasting metal availability in the two coastal areas. Among the analysed tissues digestive gland presented the highest levels of Zn, Cu, Cd and Pb. Tissues of specimens from Matosinhos exhibited high levels of Cd and from Olhão enhanced Pb concentrations. The DNA damages in digestive gland, gills and kidney were more accentuated in specimens from Matosinhos than from Olhão, suggesting a stronger effect of contaminants. Elevated strand breakages were registered in digestive gland, recognised for its ability to store and detoxify accumulated metals. The DNA damages in kidney, gills and gonads were lower, reflecting reduced metal accumulation or efficient detoxification. The broad variability of damages in the three tissues may also mirror tissue function, specific defences to genotoxicants and cell-cycle turnover.

  15. A estradiol-17beta receptor in the reproductive system of the female of Octopus vulgaris: characterization and immunolocalization.

    PubMed

    Di Cosmo, Anna; Di Cristo, Carlo; Paolucci, Marina

    2002-03-01

    In this study, for the first time we have identified an estradiol-17beta receptor (ER) in the reproductive system of the female of Octopus vulgaris. Scatchard analysis revealed that one binding component with high affinity and low capacity for the ligand was present in the cytosol, but not in the nuclear extract of the ovary and the oviduct. A steroid specificity competition assay showed that 3H-estradiol-17beta binding activity showed a preference for estradiol-17beta. DNA-cellulose chromatography confirmed the presence of one 3H-estradiol-17beta binding component. By using antibodies anti ER (578-595), we have localized by Western blotting one band of about 70 kDa. ER immunoreactivity has been localized in the nuclei of the follicle cells of the ovary, in the nuclei of the epithelium lining the proximal portion of the oviduct and in the nuclei, and in the cytoplasm of the inner region of the oviducal gland and in the cytoplasm of the outer region of the oviducal gland. These data, taken together, provide evidence that in Octopus vulgaris the ER has biochemical and immunohistochemical characteristics resembling those of ER in vertebrates.

  16. Genetic differentiation of Octopus minor (Mollusca, Cephalopoda) off the northern coast of China as revealed by amplified fragment length polymorphisms.

    PubMed

    Yang, J M; Sun, G H; Zheng, X D; Ren, L H; Wang, W J; Li, G R; Sun, B C

    2015-12-02

    Octopus minor (Sasaki, 1920) is an economically important cephalopod that is found in the northern coastal waters of China. In this study, we investigated genetic differentiation in fishery populations using amplified fragment length polymorphisms (AFLPs). A total of 150 individuals were collected from five locations: Dalian (DL), Yan-tai (YT), Qingdao (QD), Lianyungang (LY), and Zhoushan (ZS), and 243 reproducible bands were amplified using five AFLP primer combinations. The percentage of polymorphic bands ranged from 53.33 to 76.08%. Nei's genetic identity ranged from 0.9139 to 0.9713, and the genetic distance ranged from 0.0291 to 0.0900. A phylogenetic tree was constructed using the unweighted pair group method with arithmetic mean, based on the genetic distance. The DL and YT populations originated from one clade, while the QD, LY, and ZS populations originated from another. The results indicate that the O. minor stock consisted of two genetic populations with an overall significantly analogous FST value (0.1088, P < 0.05). Most of the variance was within populations. These findings will be important for more sustainable octopus fisheries, so that this marine resource can be conserved for its long-term utilization.

  17. Model based optimization of feeding regimens in aquaculture: application to the improvement of Octopus vulgaris viability in captivity.

    PubMed

    Hormiga, José A; Almansa, Eduardo; Sykes, António V; Torres, Néstor V

    2010-09-01

    The culture of common octopus (Octopus vulgaris), one important candidate to the aquaculture diversification, faces significant difficulties, mainly related with an inadequate first development stages diet. A mathematical model integrating disperse information on the nutrient composition throughout the species ontogenic development as well as on the effects of broodstock feeding and diet composition data of O. vulgaris, allowed us to predict the time evolution of paralarvae nutritional composition in terms of protein and lipid fractions and to design an optimal diet composition with the objective to ensure the maximal survival. The optimization routine showed that a diet based on the spider crab (Maja squinado) zoea composition is the most suitable for reaching the best survival rates. Results are verified by comparison with available experimental data. The obtained results and the prospective developments are a good example of how the systemic, quantitative model based approach can be used to analyse and contribute to the understanding of complex biological systems. Copyright 2009 Elsevier B.V. All rights reserved.

  18. Blue-ringed octopus (Hapalochlaena sp.) envenomation of a 4-year-old boy: a case report.

    PubMed

    Cavazzoni, Elena; Lister, Bruce; Sargent, Phillip; Schibler, Andreas

    2008-09-01

    The blue-ringed octopus (Hapalochlaena sp.) is a small animal, which can inject a toxin that produces a respiratory arrest within minutes. This envenomation is a rare occurrence with very few reported outcomes in children. A 4-year-old boy was bitten by a blue-ringed octopus (Hapalochlaena sp.) whilst playing at a popular beach in Queensland, Australia. Within ten minutes of the bite, he had vomited three times, lost the ability to stand and complained of blurred vision. An ambulance was called by the time he presented to the local emergency department (20 minutes after the bite) he had acute and progressive skeletal muscle weakness. He was intubated, ventilated, and transferred to a pediatric intensive care unit for specialized supportive care. He was ventilated for a total of 17 hours with spontaneous muscular activity returning at around 15 hours from envenomation. If not treated appropriately the bite of this small and innocuous looking animal could have lead to death within minutes. This case report serves as a reminder of how appropriate treatment can ensure discharge from hospital with no long-term consequences. It also highlights the importance of education for beach goers and in particular parents to prevent exposure of tetrodotoxin to children.

  19. Two new species of dicyemid mesozoans (Dicyemida: Dicyemidae) from Octopus maya Voss & Solis-Ramirez (Octopodidae) off Yucatan, Mexico.

    PubMed

    Castellanos-Martinez, Sheila; Aguirre-Macedo, M Leopoldina; Furuya, Hidetaka

    2016-07-01

    Two new dicyemid species are described from the endemic cephalopod Octopus maya Voss & Solis-Ramirez collected off Yucatan, Mexico. The renal sacs of 40 juvenile and adult octopuses from four localities were examined. Dicyema hochbergi n. sp. is a medium-sized species that reaches 2,245 µm in length. The vermiform stages consist of 18-24 peripheral cells, a conical calotte and the extension of the axial cell between the base and middle of the metapolar cells. Infusoriform embryos consist of 39 cells with urn cell containing one germinal cell, two nuclei and solid refringent bodies. Dicyema mexcayae n. sp. is a relatively small species that reaches 1,114 µm in length. The vermiform stages are constituted by 14-16 peripheral cells, an elongate calotte and the axial cell extending forward to the middle of the metapolar cells. The infusoriform embryos consist of 37 cells, two solid refringent bodies and urn cells with two nuclei each. The present study represents the first description of a dicyemid species from O. maya and increases the number of described species from Mexican waters to 11.

  20. Octopus visual system: a functional MRI model for detecting neuronal electric currents without a blood-oxygen-level-dependent confound.

    PubMed

    Jiang, Xia; Lu, Hanbing; Shigeno, Shuichi; Tan, Li-Hai; Yang, Yihong; Ragsdale, Clifton W; Gao, Jia-Hong

    2014-11-01

    Despite the efforts that have been devoted to detecting the transient magnetic fields generated by neuronal firing, the conclusion that a functionally relevant signal can be measured with MRI is still controversial. For human studies of neuronal current MRI (nc-MRI), the blood-oxygen-level-dependent (BOLD) effect remains an irresolvable confound. For tissue studies where hemoglobin is removed, natural sensory stimulation is not possible. This study investigates the feasibility of detecting a physiologically induced nc-MRI signal in vivo in a BOLD-free environment. The cephalopod mollusc Octopus bimaculoides has vertebrate-like eyes, large optic lobes (OLs), and blood that does not contain hemoglobin. Visually evoked potentials were measured in the octopus retina and OL by electroretinogram and local field potential. nc-MRI scans were conducted at 9.4 Tesla to capture these activities. Electrophysiological recording detected strong responses in the retina and OL in vivo; however, nc-MRI failed to demonstrate any statistically significant signal change with a detection threshold of 0.2° for phase and 0.2% for magnitude. Experiments in a dissected eye-OL preparation yielded similar results. These findings in a large hemoglobin-free nervous system suggest that sensory evoked neuronal magnetic fields are too weak for direct detection with current MRI technology. Copyright © 2013 Wiley Periodicals, Inc.

  1. Quaternary Structure Heterogeneity of Oligomeric Proteins: A SAXS and SANS Study of the Dissociation Products of Octopus vulgaris Hemocyanin

    PubMed Central

    Spinozzi, Francesco; Mariani, Paolo; Mičetić, Ivan; Ferrero, Claudio; Pontoni, Diego; Beltramini, Mariano

    2012-01-01

    Octopus vulgaris hemocyanin shows a particular self-assembling pattern, characterized by a hierarchical organization of monomers. The highest molecular weight aggregate is a decamer, the stability of which in solution depends on several parameters. Different pH values, buffer compositions, H2O/D2O ratios and Hofmeister’s salts result in modifications of the aggregation state of Octopus vulgaris hemocyanin. The new QUAFIT method, recently applied to derive the structure of the decameric and the monomeric assembly from small-angle scattering data, is used here to model the polydisperse system that results from changing the solution conditions. A dataset of small-angle X-rays and neutron scattering curves is analysed by QUAFIT to derive structure, composition and concentration of different assemblies present in solution. According to the hierarchy of the association/dissociation processes and the possible number of different aggregation products in solution, each sample has been considered as a heterogeneous mixture composed of the entire decamer, the dissociated “loose” monomer and all the intermediate dissociation products. Scattering curves corresponding to given experimental conditions are well fitted by using a linear combination of single particle form factors. QUAFIT has proved to be a method of general validity to describe solutions of proteins that, even after purification processes, result to be intrinsically heterogeneous. PMID:23166737

  2. Using Age-Based Life History Data to Investigate the Life Cycle and Vulnerability of Octopus cyanea

    PubMed Central

    Herwig, Jade N.; Depczynski, Martial; Roberts, John D.; Semmens, Jayson M.; Gagliano, Monica; Heyward, Andrew J.

    2012-01-01

    Octopus cyanea is taken as an unregulated, recreationally fished species from the intertidal reefs of Ningaloo, Western Australia. Yet despite its exploitation and importance in many artisanal fisheries throughout the world, little is known about its life history, ecology and vulnerability. We used stylet increment analysis to age a wild O. cyanea population for the first time and gonad histology to examine their reproductive characteristics. O. cyanea conforms to many cephalopod life history generalisations having rapid, non-asymptotic growth, a short life-span and high levels of mortality. Males were found to mature at much younger ages and sizes than females with reproductive activity concentrated in the spring and summer months. The female dominated sex-ratios in association with female brooding behaviours also suggest that larger conspicuous females may be more prone to capture and suggests that this intertidal octopus population has the potential to be negatively impacted in an unregulated fishery. Size at age and maturity comparisons between our temperate bordering population and lower latitude Tanzanian and Hawaiian populations indicated stark differences in growth rates that correlate with water temperatures. The variability in life history traits between global populations suggests that management of O. cyanea populations should be tailored to each unique set of life history characteristics and that stylet increment analysis may provide the integrity needed to accurately assess this. PMID:22912898

  3. Origin of the human alcohol dehydrogenase system: implications from the structure and properties of the octopus protein.

    PubMed

    Kaiser, R; Fernández, M R; Parés, X; Jörnvall, H

    1993-12-01

    In contrast to the multiplicity of alcohol dehydrogenase in vertebrates, a class III type of the enzyme [i.e., a glutathione-dependent formaldehyde dehydrogenase; formaldehyde; NAD+ oxidoreductase (glutathione-formylating), EC 1.2.1.1.] is the only form detectable in appreciable yield in octopus. It is enzymatically and structurally highly similar to the human class III enzyme, with limited overall residue differences (26%) and only a few conservative residue exchanges at the substrate and coenzyme pockets, reflecting "constant" characteristics of this class over wide time periods. It is distinct from the ethanol-active "variable" class I type of the enzyme (i.e., classical liver alcohol dehydrogenase; alcohol:NAD+ oxidoreductase, EC 1.1.1.1). The residue conservation of class III is also spaced differently from that of class I but is typical of that of proteins in general, emphasizing that class I, with divergence at three functional segments, is the form with deviating properties. In spite of the conservation in class III, surface charges differ considerably. The apparent absence of a class I enzyme in octopus and the constant nature of the class III enzyme support the concept of a duplicative origin of the class I line from the ancient class III form. Still more distant relationships define further enzyme lines that have subunits with other properties.

  4. Differential postsynaptic distribution of GluRs 1-4 on cartwheel and octopus cell somata in the gerbil cochlear nucleus.

    PubMed

    Schwartz, I R; Keh, A; Eager, P R

    2000-09-01

    Differences were demonstrated in the distribution of glutamate receptors (GluR) 1, 2, 2/3 and 4 postsynaptic immunoreactivity (PSIR) on the somata of cartwheel and octopus cells in the adult gerbil cochlear nucleus (CN). Montages of electron micrographs of cartwheel and octopus cells immunoreacted with antibodies to GluR 1, 2, 2/3 and 4 were prepared. The number of synaptic terminals with PSIR were counted on all cells for each antibody, normalized to the total length of somatic surface analyzed. The density of terminals apposed to PSIR on octopus cells was similar for the antibodies GluR1, 2/3 and 4, but significantly less for GluR2. On cartwheel somata the numbers of terminals apposed to immunoreactive postsynaptic specializations with GluR1, 2, 2/3 or 4 were not significantly different from each other. The density of terminals apposed to GluR2/3 and 4 positive postsynaptic specializations was significantly less on cartwheel cells than on octopus somata. The data suggest that the decreased presence of the GluR2 subunit, which confers calcium impermeability to the assembled receptor and slower gating kinetics to receptors with a high GluR4 content, is the major difference in the AMPA receptors on the somata of these cell types. The presence on cartwheel cells of a majority of AMPA receptors which contain GluR2 may account for the fact that cartwheel cells respond to shocks to the auditory nerve with 100 ms excitatory postsynaptic potentials (EPSPs), while octopus cells, most of whose AMPA receptors lack GluR2, respond with 1 ms EPSPs.

  5. Molecular basis for the polymerization of octopus lens S-crystallin.

    PubMed Central

    Chang, H C; Lin, T L; Chang, G G

    2000-01-01

    S-Crystallin from octopus lens has a tertiary structure similar to sigma-class glutathione transferase (GST). However, after isolation from the lenses, S-crystallin was found to aggregate more easily than sigma-GST. In vitro experiments showed that the lens S-crystallin can be polymerized and finally denatured at increasing concentration of urea or guanidinium chloride (GdmCl). In the intermediate concentrations of urea or GdmCl, the polymerized form of S-crystallin is aggregated, as manifested by the increase in light scattering and precipitation of the protein. There is a delay time for the initiation of polymerization. Both the delay time and rate of polymerization depend on the protein concentration. The native protein showed a maximum fluorescence emission spectrum at 341 nm. The GdmCl-denatured protein exhibited two fluorescence maxima at 310 nm and 358 nm, respectively, whereas the urea-denatured protein showed a fluorescence peak at 358 nm with a small peak at 310 nm. The fluorescence intensity was quenched. Monomers, dimers, trimers, and polymers of the native protein were observed by negative-stain electron microscopic analysis. The aggregated form, however, showed irregular structure. The aggregate was solubilized in high concentrations of urea or GdmCl. The redissolved denatured protein showed an identical fluorescence spectrum to the protein solution that was directly denatured with high concentrations of urea or GdmCl. The denatured protein was readily refolded to its native state by diluting with buffer solution. The fluorescence spectrum of the renatured protein solution was similar to that of the native form. The phase diagrams for the S-crystallin in urea and GdmCl were constructed. Both salt concentration and pH value of the solution affect the polymerization rate, suggesting the participation of ionic interactions in the polymerization. Comparison of the molecular models of the S-crystallin and sigma-GST suggests that an extra ion-pair between

  6. Ongoing compound field potentials from octopus brain are labile and vertebrate-like.

    PubMed

    Bullock, T H

    1984-05-01

    Ongoing electrical activity was recorded from the brain of the virtually intact, semirestrained, unanesthetized octopus by semimicroelectrodes thrust through the cartilage into the optic, vertical or basal lobe. With flexible lead-in wires such electrodes were carried by and moved with the head without causing movement artifacts. Controls suggest that the activity reported comes from the brain; it is reversibly flattened by doses of urethane that do not embarrass respiration. Muscle potentials are only troublesome on occasion. Seen through a wideband filter, neuronal spikes are usually small or below noise level under these conditions; slow waves (1-70 Hz) dominate, with a maximum less than 25 Hz, usually less than 10 Hz and no consistent sharp peaks. The fall in power above ca. 25 Hz is usually slower than in the typical vertebrate EEG but the average power spectrum is much more like those of vertebrate brains than of cerebral ganglia of other invertebrates (insect, crustacean, gastropod). Variance among sample epochs is large, e.g. short spells may have relatively much more low frequency (less than 25 Hz) or more 'hashy' high frequency (greater than 50 Hz) energy; there may be runs of spikes. Fluctuation in the composition of ongoing activity is graphically shown by writing out in parallel the outputs of several narrow band (one octave) filters; this shows irregular low frequency waxing and waning of the amplitude in each band. The envelopes were computed and their peak power is around 1 Hz or lower; the waxing and waning in the several bands is sometimes strongly correlated, especially when the envelope amplitude is large and slow. Optic lobe activity tends usually to be faster, with more small spikey hash than in the vertical lobe. The described electrical activity of the brain is strikingly episodic; it is recorded during seconds or minutes separated by long intervals of nearly electrical silence (10-40 dB lower power; the difference larger at frequencies

  7. S-crystallin and arginine kinase bind F-actin in light- and dark-adapted octopus retinas.

    PubMed

    Zuniga, Freddi Isaac; Ochoa, Gina H; Kelly, Shannon D; Robles, Laura J

    2004-05-01

    Rhabdomere microvilli dramatically reorganize in conditions of light and dark. This reorganization involves remodeling of the microvillus actin cytoskeleton. We are using the rhabdomeric retina of Octopus bimaculoides to identify actin-binding proteins that may be involved in this remodeling. Octopus were light-/dark-adapted, retinas separated into dorsal and ventral halves, and homogenized. Actin-binding proteins were recognized using F-actin overlay blot assays and selected proteins from the overlays were identified using N-terminal sequencing methods or mass spectroscopy. Protein concentrations were quantified and compared by statistical analysis. Total protein gels of light-/dark-adapted, ventral/dorsal halves were almost identical except for a protein band at 26 kD. The relative amount of this protein in the dark was almost double that found in the light. The levels of other proteins did not vary significantly between the light and dark. F-actin overlays also showed matching patterns of actin-binding proteins except for the 26 kD protein. Although the 26 kD protein from light-adapted retinas transferred to the blotting membranes, it did not bind F-actin while the 26 kD protein on overlays from dark-adapted retinas always demonstrated F-actin binding. Besides the 26 kD protein, other proteins at 200 kD, 80 kD, 40 kD appeared on the overlays. These proteins and the 26 kD protein were sequenced and identified as hemocynanin, transitional ER ATPase, arginine kinase and S-crystallin, respectively. The amount of S-crystallin present in the octopus retina is significantly greater in dark-adapted retinas and it binds to F-actin. In the light, the level of S-crystallin is greatly reduced and there is no apparent F-actin binding. No other studies, to our knowledge, show that S-crystallin binds to the actin cytoskeleton or that its expression is regulated by light. Arginine kinase may provide energy for cytoskeletal remodeling as it may in other neural tissues.

  8. Contributions of ion conductances to the onset responses of octopus cells in the ventral cochlear nucleus: simulation results.

    PubMed

    Cai, Y; McGee, J; Walsh, E J

    2000-01-01

    The onset response pattern displayed by octopus cells has been attributed to intrinsic membrane properties, low membrane impedance, and/or synaptic inputs. Although the importance of a low membrane impedance generally is acknowledged as an essential component, views differ on the role that ion channels play in producing the onset response. In this study, we use a computer model to investigate the contributions of ion channels to the responses of octopus cells. Simulations using current ramps indicate that, during the "ramp-up" stage, the membrane depolarizes, activating a low-threshold K(+) channel, K(LT), which increases membrane conductance and dynamically increases the current required to evoke an action potential. As a result, the model is sensitive to the rate that membrane potential changes when initiating an action potential. Results obtained when experimentally recorded spike trains of auditory-nerve fibers served as model inputs (simulating acoustic stimulation) demonstrate that a model with K(LT) conductance as the dominant conductance produces realistic onset response patterns. Systematically replacing the K(LT) conductance by a h-type conductance (which corresponds to a hyperpolarization-activated inward rectifier current, I(h)) or by a leakage conductance reduces the model's sensitivity to rate of change in membrane potential, and the model's response to "acoustic stimulation" becomes more chopper-like. Increasing the h-type conductance while maintaining a large K(LT) conductance causes an increase in threshold to both current steps and acoustic stimulation but does not significantly affect the model's sensitivity to rate of change in membrane potential and the onset response pattern under acoustic stimulation. These findings support the idea that K(LT), which is activated during depolarization, is the primary membrane conductance determining the response properties of octopus cells, and its dynamic role cannot be provided by a static membrane

  9. Positive Catch & Economic Benefits of Periodic Octopus Fishery Closures: Do Effective, Narrowly Targeted Actions ‘Catalyze’ Broader Management?

    PubMed Central

    Oliver, Thomas A.; Oleson, Kirsten L. L.; Ratsimbazafy, Hajanaina; Raberinary, Daniel; Benbow, Sophie; Harris, Alasdair

    2015-01-01

    Overview Eight years of octopus fishery records from southwest Madagascar reveal significant positive impacts from 36 periodic closures on: (a) fishery catches and (b) village fishery income, such that (c) economic benefits from increased landings outweigh costs of foregone catch. Closures covered ~20% of a village’s fished area and lasted 2-7 months. Fishery Catches from Each Closed Site Octopus landings and catch per unit effort (CPUE) significantly increased in the 30 days following a closure’s reopening, relative to the 30 days before a closure (landings: +718%, p<0.0001; CPUE: +87%, p<0.0001; n = 36). Open-access control sites showed no before/after change when they occurred independently of other management (“no ban”, n = 17/36). On the other hand, open-access control sites showed modest catch increases when they extended a 6-week seasonal fishery shutdown (“ban”, n = 19/36). The seasonal fishery shutdown affects the entire region, so confound all potential control sites. Fishery Income in Implementing Villages In villages implementing a closure, octopus fishery income doubled in the 30 days after a closure, relative to 30 days before (+132%, p<0.001, n = 28). Control villages not implementing a closure showed no increase in income after “no ban” closures and modest increases after “ban” closures. Villages did not show a significant decline in income during closure events. Net Economic Benefits from Each Closed Site Landings in closure sites generated more revenue than simulated landings assuming continued open-access fishing at that site (27/36 show positive net earnings; mean +$305/closure; mean +57.7% monthly). Benefits accrued faster than local fishers’ time preferences during 17-27 of the 36 closures. High reported rates of illegal fishing during closures correlated with poor economic performance. Broader Co-Management We discuss the implications of our findings for broader co-management arrangements, particularly for catalyzing

  10. Localization of corticotropin-releasing factor-immunoreactive nervous tissue and colocalization with neuropeptide Y-like substance in the optic lobe and peduncle complex of the octopus (Octopus vulgaris).

    PubMed

    Suzuki, Hirohumi; Muraoka, Tomofusa; Yamamoto, Toshiharu

    2003-07-01

    The distribution of corticotropin-releasing factor (CRF)-like immunoreactivity and its colocalization with neuropeptide Y (NPY)-like substances were investigated in the optic lobe and peduncle complex of the octopus (Octopus vulgaris) using immunohistochemical techniques. In the optic lobe cortex, CRF-immunoreactive (CRF-IR) and NPY-immunonegative varicose fibers were observed in the plexiform layer. In the medulla, CRF-IR somata were seen in the cell islands, and CRF-IR varicose fibers were observed in the neuropil. About half of the CRF-IR structures in the medulla showed NPY-like immunoreactivity. In the peduncle lobe, no CRF-IR somata but abundant CRF-IR varicose fibers were observed, and about half of them showed NPY-like immunoreactivity. In the olfactory lobe, CRF-IR somata and abundant CRF-IR varicose fibers were observed. Almost all the CRF-IR somata located in the posterior olfactory lobule showed NPY-like immunoreactivity, whereas those seen in the median olfactory lobule were immunonegative for NPY. About half of the CRF-IR fibers in the anterior lobule neuropil were immunopositive for NPY, but those in the median and posterior lobule neuropils were immunonegative for NPY. In the optic gland, almost all the CRF-IR varicose fibers were immunoreactive for NPY. Western blot analysis of the optic lobe and peduncle complex indicated that anti-CRF antiserum labeled approximate 16.4- and 14.6-kDa bands and that anti-NPY antiserum labeled an approximate 16.2-kDa band. CRF-IR and NPY-immunoreactive neurons in the optic lobe may participate in the modulation of visual information and those in the optic gland may be involved in the regulation of endocrine function.

  11. Real-space grids and the Octopus code as tools for the development of new simulation approaches for electronic systems

    NASA Astrophysics Data System (ADS)

    Andrade, Xavier; Strubbe, David; De Giovannini, Umberto; Larsen, Ask Hjorth; Oliveira, Micael J. T.; Alberdi-Rodriguez, Joseba; Varas, Alejandro; Theophilou, Iris; Helbig, Nicole; Verstraete, Matthieu J.; Stella, Lorenzo; Nogueira, Fernando; Aspuru-Guzik, Alán; Castro, Alberto; Marques, Miguel A. L.; Rubio, Angel

    Real-space grids are a powerful alternative for the simulation of electronic systems. One of the main advantages of the approach is the flexibility and simplicity of working directly in real space where the different fields are discretized on a grid, combined with competitive numerical performance and great potential for parallelization. These properties constitute a great advantage at the time of implementing and testing new physical models. Based on our experience with the Octopus code, in this article we discuss how the real-space approach has allowed for the recent development of new ideas for the simulation of electronic systems. Among these applications are approaches to calculate response properties, modeling of photoemission, optimal control of quantum systems, simulation of plasmonic systems, and the exact solution of the Schr\\"odinger equation for low-dimensionality systems.

  12. Assembly of Octopus dofleini hemocyanin. A study of the kinetics by sedimentation, light scattering and electron microscopy.

    PubMed

    van Holde, K E; Miller, K; Schabtach, E; Libertini, L

    1991-01-20

    The kinetics of association of Octopus dofleini hemocyanin subunits to form the native decameric molecule have been studied with a combination of sedimentation, light scattering and electron microscopy. The reaction, initiated by addition of magnesium, is relatively slow, requiring hours to reach completion, with monomer and decamer as predominant molecular species throughout. Analysis of the light-scattering data, including stopped-flow studies, reveals an initial lag period in the reaction, followed by a second-order process that is rate limiting. The lag period depends on both protein and magnesium ion concentration. Electron microscope studies reveal intermediates in the process, and support a model of assembly in which nucleation begins at the dimer level. Theoretical models for the process are compared.

  13. Real-space grids and the Octopus code as tools for the development of new simulation approaches for electronic systems.

    PubMed

    Andrade, Xavier; Strubbe, David; De Giovannini, Umberto; Larsen, Ask Hjorth; Oliveira, Micael J T; Alberdi-Rodriguez, Joseba; Varas, Alejandro; Theophilou, Iris; Helbig, Nicole; Verstraete, Matthieu J; Stella, Lorenzo; Nogueira, Fernando; Aspuru-Guzik, Alán; Castro, Alberto; Marques, Miguel A L; Rubio, Angel

    2015-12-21

    Real-space grids are a powerful alternative for the simulation of electronic systems. One of the main advantages of the approach is the flexibility and simplicity of working directly in real space where the different fields are discretized on a grid, combined with competitive numerical performance and great potential for parallelization. These properties constitute a great advantage at the time of implementing and testing new physical models. Based on our experience with the Octopus code, in this article we discuss how the real-space approach has allowed for the recent development of new ideas for the simulation of electronic systems. Among these applications are approaches to calculate response properties, modeling of photoemission, optimal control of quantum systems, simulation of plasmonic systems, and the exact solution of the Schrödinger equation for low-dimensionality systems.

  14. Body size, growth and life span: implications for the polewards range shift of Octopus tetricus in south-eastern Australia.

    PubMed

    Ramos, Jorge E; Pecl, Gretta T; Moltschaniwskyj, Natalie A; Strugnell, Jan M; León, Rafael I; Semmens, Jayson M

    2014-01-01

    Understanding the response of any species to climate change can be challenging. However, in short-lived species the faster turnover of generations may facilitate the examination of responses associated with longer-term environmental change. Octopus tetricus, a commercially important species, has undergone a recent polewards range shift in the coastal waters of south-eastern Australia, thought to be associated with the southerly extension of the warm East Australian Current. At the cooler temperatures of a polewards distribution limit, growth of a species could be slower, potentially leading to a bigger body size and resulting in a slower population turnover, affecting population viability at the extreme of the distribution. Growth rates, body size, and life span of O. tetricus were examined at the leading edge of a polewards range shift in Tasmanian waters (40°S and 147°E) throughout 2011. Octopus tetricus had a relatively small body size and short lifespan of approximately 11 months that, despite cooler temperatures, would allow a high rate of population turnover and may facilitate the population increase necessary for successful establishment in the new extended area of the range. Temperature, food availability and gender appear to influence growth rate. Individuals that hatched during cooler and more productive conditions, but grew during warming conditions, exhibited faster growth rates and reached smaller body sizes than individuals that hatched into warmer waters but grew during cooling conditions. This study suggests that fast growth, small body size and associated rapid population turnover may facilitate the range shift of O. tetricus into Tasmanian waters.

  15. Neuropeptidergic control of the optic gland of Octopus vulgaris: FMRF-amide and GnRH immunoreactivity.

    PubMed

    Di Cosmo, A; Di Cristo, C

    1998-08-17

    In cephalopods, the endocrine optic glands on the optic tract control the maturation of the gonads. The glands are innervated by the optic gland nerve, which originates in the central nervous system. To explore the involvement of neuropeptides in the nervous control of the optic gland of Octopus vulgaris, the presence and distribution of Phe-Met-Arg-Phe-NH2 (FMRF-amide)-like and gonadotropin releasing homone (GnRH)-like peptides were examined in the central nervous system and optic gland by immunohistochemistry. For GnRH immunodetection, antibodies against four different forms of GnRH were used: cGnRH-I, cGnRH-II, sGnRH, and mGnRH. The optic gland nerve provides direct and indirect signals coming from the centres of integration of chemical, visual, and olfactive stimuli to modulate the glandular activity. In these centres, the subpedunculate area, the olfactory and optic lobes, and FMRF-amide-like and GnRH-like immunoreactivities were detected. The subpedunculate area seems to be the source of the FMRF-amide-like peptide, whereas the posterior olfactory lobule is the source of the GnRH-like peptide. The immunoreactive fibres for both neuropeptides leave their sources and directly enter the optic gland nerve. FMRF-amide- and GnRH-immunoreactive nerve endings are seen on the glandular cells. The evidence of a possible neuropeptidergic control of optic gland activity reinforces the analogies and the functional parallels in the octopus, insect, crustacean, and vertebrate hormonal systems.

  16. Relationship between optical coherence tomography sector peripapillary angioflow-density and Octopus visual field cluster mean defect values

    PubMed Central

    2017-01-01

    Purpose To compare the relationship of Octopus perimeter cluster mean-defect (cluster MD) values with the spatially corresponding optical coherence tomography (OCT) sector peripapillary angioflow vessel-density (PAFD) and sector retinal nerve fiber layer thickness (RNFLT) values. Methods High quality PAFD and RNFLT images acquired on the same day with the Angiovue/RTVue-XR Avanti OCT (Optovue Inc., Fremont, USA) on 1 eye of 27 stable early-to-moderate glaucoma, 22 medically controlled ocular hypertensive and 13 healthy participants were analyzed. Octopus G2 normal visual field test was made within 3 months from the imaging. Results Total peripapillary PAFD and RNFLT showed similar strong positive correlation with global mean sensitivity (r-values: 0.6710 and 0.6088, P<0.0001), and similar (P = 0.9614) strong negative correlation (r-values: -0.4462 and -0.4412, P≤0.004) with global MD. Both inferotemporal and superotemporal sector PAFD were significantly (≤0.039) lower in glaucoma than in the other groups. No significant difference between the corresponding inferotemporal and superotemporal parameters was seen. The coefficient of determination (R2) calculated for the relationship between inferotemporal sector PAFD and superotemporal cluster MD (0.5141, P<0.0001) was significantly greater than that between inferotemporal sector RNFLT and superotemporal cluster MD (0.2546, P = 0.0001). The R2 values calculated for the relationships between superotemporal sector PAFD and RNFLT, and inferotemporal cluster MD were similar (0.3747 and 0.4037, respectively, P<0.0001). Conclusion In the current population the relationship between inferotemporal sector PAFD and superotemporal cluster MD was strong. It was stronger than that between inferotemporal sector RNFLT and superotemporal cluster MD. Further investigations are necessary to clarify if our results are valid for other populations and can be usefully applied for glaucoma research. PMID:28152106

  17. Dose-dependent effects of the clinical anesthetic isoflurane on Octopus vulgaris: a contribution to cephalopod welfare.

    PubMed

    Polese, Gianluca; Winlow, William; Di Cosmo, Anna

    2014-12-01

    Recent progress in animal welfare legislation relating to invertebrates has provoked interest in methods for the anesthesia of cephalopods, for which different approaches to anesthesia have been tried but in most cases without truly anesthetizing the animals. For example, several workers have used muscle relaxants or hypothermia as forms of "anesthesia." Several inhalational anesthetics are known to act in a dose-dependent manner on the great pond snail Lymnaea stagnalis, a pulmonate mollusk. Here we report, for the first time, on the effects of clinical doses of the well-known inhalational clinical anesthetic isoflurane on the behavioral responses of the common octopus Octopus vulgaris. In each experiment, isoflurane was equilibrated into a well-aerated seawater bath containing a single adult O. vulgaris. Using a web camera, we recorded each animal's response to touch stimuli eliciting withdrawal of the arms and siphon and observed changes in the respiratory rate and the chromatophore pattern over time (before, during, and after application of the anesthetic). We found that different animals of the same size responded with similar behavioral changes as the isoflurane concentration was gradually increased. After gradual application of 2% isoflurane for a maximum of 5 min (at which time all the responses indicated deep anesthesia), the animals recovered within 45-60 min in fresh aerated seawater. Based on previous findings in gastropods, we believe that the process of anesthesia induced by isoflurane is similar to that previously observed in Lymnaea. In this study we showed that isoflurane is a good, reversible anesthetic for O. vulgaris, and we developed a method for its use.

  18. Body Size, Growth and Life Span: Implications for the Polewards Range Shift of Octopus tetricus in South-Eastern Australia

    PubMed Central

    Ramos, Jorge E.; Pecl, Gretta T.; Moltschaniwskyj, Natalie A.; Strugnell, Jan M.; León, Rafael I.; Semmens, Jayson M.

    2014-01-01

    Understanding the response of any species to climate change can be challenging. However, in short-lived species the faster turnover of generations may facilitate the examination of responses associated with longer-term environmental change. Octopus tetricus, a commercially important species, has undergone a recent polewards range shift in the coastal waters of south-eastern Australia, thought to be associated with the southerly extension of the warm East Australian Current. At the cooler temperatures of a polewards distribution limit, growth of a species could be slower, potentially leading to a bigger body size and resulting in a slower population turnover, affecting population viability at the extreme of the distribution. Growth rates, body size, and life span of O. tetricus were examined at the leading edge of a polewards range shift in Tasmanian waters (40°S and 147°E) throughout 2011. Octopus tetricus had a relatively small body size and short lifespan of approximately 11 months that, despite cooler temperatures, would allow a high rate of population turnover and may facilitate the population increase necessary for successful establishment in the new extended area of the range. Temperature, food availability and gender appear to influence growth rate. Individuals that hatched during cooler and more productive conditions, but grew during warming conditions, exhibited faster growth rates and reached smaller body sizes than individuals that hatched into warmer waters but grew during cooling conditions. This study suggests that fast growth, small body size and associated rapid population turnover may facilitate the range shift of O. tetricus into Tasmanian waters. PMID:25090250

  19. Purification and Characterization of a Protease Produced by a Planomicrobium sp. L-2 from Gut of Octopus vulgaris

    PubMed Central

    Liu, Qing; Sun, Shujing; Piao, Meizi; Yang, Ji Young

    2013-01-01

    Protease widely exists in the digestive tract of animals and humans, playing a very important role in protein digestion and absorption. In this study, a high protease-producing strain Planomicrobium sp. L-2 was isolated and identified from the digestive tract of Octopus variabilis. The strain was identified by physiological and biochemical experiments and 16S rDNA sequences analysis. A protease was obtained from the strain Planomicrobium sp. L-2 through ammonium sulfate precipitation, dialysis and enrichment, DEAE-Sephadex A50 anion-exchange chromatography, and Sephadex G-100 gel chromatography. The molecular weight and properties of the protease were characterized, including optimum temperature and pH, thermal stability, protease inhibitions and metal ions. According to our results, the protease from Planomicrobium sp. L-2 strain designated as F1-1 was obtained by three-step separation and purification from crude enzyme. The molecular weight of the protease was 61.4 kDa and its optimum temperature was 40°C. The protease F1-1 showed a broad pH profile for casein hydrolysis between 5.0~11.0. No residual activity was observed after incubation for 40 min at 60°C and 60 min at 50°C. F1-1 protease was inhibited by Mn2+, Hg2+, Pb2+, Zn2+, and Cu2+ ions, as well as PMSF, indicating that the protease F1-1 was a serine protease. Additionally, research basis provided by this study could be considered for industrial application of octopus intestinal proteases. PMID:24551830

  20. Relationship between optical coherence tomography sector peripapillary angioflow-density and Octopus visual field cluster mean defect values.

    PubMed

    Holló, Gábor

    2017-01-01

    To compare the relationship of Octopus perimeter cluster mean-defect (cluster MD) values with the spatially corresponding optical coherence tomography (OCT) sector peripapillary angioflow vessel-density (PAFD) and sector retinal nerve fiber layer thickness (RNFLT) values. High quality PAFD and RNFLT images acquired on the same day with the Angiovue/RTVue-XR Avanti OCT (Optovue Inc., Fremont, USA) on 1 eye of 27 stable early-to-moderate glaucoma, 22 medically controlled ocular hypertensive and 13 healthy participants were analyzed. Octopus G2 normal visual field test was made within 3 months from the imaging. Total peripapillary PAFD and RNFLT showed similar strong positive correlation with global mean sensitivity (r-values: 0.6710 and 0.6088, P<0.0001), and similar (P = 0.9614) strong negative correlation (r-values: -0.4462 and -0.4412, P≤0.004) with global MD. Both inferotemporal and superotemporal sector PAFD were significantly (≤0.039) lower in glaucoma than in the other groups. No significant difference between the corresponding inferotemporal and superotemporal parameters was seen. The coefficient of determination (R2) calculated for the relationship between inferotemporal sector PAFD and superotemporal cluster MD (0.5141, P<0.0001) was significantly greater than that between inferotemporal sector RNFLT and superotemporal cluster MD (0.2546, P = 0.0001). The R2 values calculated for the relationships between superotemporal sector PAFD and RNFLT, and inferotemporal cluster MD were similar (0.3747 and 0.4037, respectively, P<0.0001). In the current population the relationship between inferotemporal sector PAFD and superotemporal cluster MD was strong. It was stronger than that between inferotemporal sector RNFLT and superotemporal cluster MD. Further investigations are necessary to clarify if our results are valid for other populations and can be usefully applied for glaucoma research.

  1. Comparison of structure-function relationship between corresponding retinal nerve fibre layer thickness and Octopus visual field cluster defect values determined by normal and tendency-oriented strategies.

    PubMed

    Holló, Gábor

    2017-02-01

    Previously, we found a strong structure-function relationship between Octopus visual field cluster sensitivity and corresponding sector retinal nerve fibre layer thickness (RNFLT) values, using normal strategy and 16 custom-made cluster-sector pairs. However, Octopus commercially offers 10 clusters, correction for diffuse defect (corrected clusters) and tendency-oriented perimetry (TOP) strategy. In the current investigation, we evaluated structure-function relationship for these conditions, respectively. Twenty-four healthy, 45 ocular hypertensive and 63 glaucoma eyes underwent Octopus perimetry (normal and TOP strategies) and RNFLT measurements on the same day. Pearson's correlation between corresponding cluster defect and sector RNFLT values was investigated. Correlation between the corresponding cluster defect and sector RNFLT values was significant (p<0.0001) for all clusters, with both test strategies. The r values ranged from -0.3529 and -0.3877 to -0.5798 and -0.5893, respectively. The highest r values were found for the inferotemporal RNFLT sector superior and superior paracentral cluster pairs with both strategies. No difference in correlation was seen between the strategies (p≥0.183). For corrected clusters, significant correlation (p<0.01) was seen only for two inferotemporal and one superotemporal RNFLT sectors, with both strategies (r values: -0.2446, -0.2375; -0.3526, -0.3119; -0.2392, -0.2340, respectively). Octopus normal and TOP strategies provide similar, moderate-to-strong negative correlation between the corresponding cluster defect and sector RNFLT values for all 10 manufacturer-provided clusters. For corrected clusters the relationship is poor, which suggests that by correcting for diffuse sensitivity loss some local glaucomatous defect is removed. For structure-function based clinical decisions, use of TOP is possible but use of corrected clusters is not recommended. Published by the BMJ Publishing Group Limited. For permission to use

  2. A novel rhodopsin kinase in octopus photoreceptor possesses a pleckstrin homology domain and is activated by G protein betagamma-subunits.

    PubMed

    Kikkawa, S; Yoshida, N; Nakagawa, M; Iwasa, T; Tsuda, M

    1998-03-27

    G protein-coupled receptor kinases (GRKs) play an important role in stimulus-dependent receptor phosphorylation and desensitization of the receptors. Mammalian rhodopsin kinase (RK) and beta-adrenergic receptor kinase (betaARK) are the most studied members among known GRKs. In this work, we purified RK from octopus photoreceptors for the first time from invertebrate tissues. The molecular mass of the purified enzyme was 80 kDa as estimated by SDS-polyacrylamide gel electrophoresis, and this was 17 kDa larger than that of the vertebrate enzymes. Unlike vertebrate RK, octopus RK (ORK) was directly activated by betagamma-subunits of a photoreceptor G protein. We examined the effects of various known activators and inhibitors of GRKs on the activity of the purified ORK and found that their effects were different from those on either bovine RK or betaARK. To analyze the primary structure of the enzyme, we cloned the cDNA encoding ORK from an octopus retinal cDNA library. The deduced amino acid sequence of the cDNA was highly homologous to betaARK over the entire molecule, including a pleckstrin homology domain located in the C-terminal region, and homology to RK was significantly lower. Furthermore, Western blot analysis of various octopus tissues with an antibody against the purified ORK showed that ORK is expressed solely in the retina, which confirmed the identity of the enzyme as rhodopsin kinase. Thus, ORK appears to represent a unique subgroup in the GRK family, which is distinguished from vertebrate RK.

  3. Signature Lipids and Stable Carbon Isotope Analyses of Octopus Spring Hyperthermophilic Communities Compared with Those of Aquificales Representatives

    PubMed Central

    Jahnke, Linda L.; Eder, Wolfgang; Huber, Robert; Hope, Janet M.; Hinrichs, Kai-Uwe; Hayes, John M.; Des Marais, David J.; Cady, Sherry L.; Summons, Roger E.

    2001-01-01

    The molecular and isotopic compositions of lipid biomarkers of cultured Aquificales genera have been used to study the community and trophic structure of the hyperthermophilic pink streamers and vent biofilm from Octopus Spring. Thermocrinis ruber, Thermocrinis sp. strain HI 11/12, Hydrogenobacter thermophilus TK-6, Aquifex pyrophilus, and Aquifex aeolicus all contained glycerol-ether phospholipids as well as acyl glycerides. The n-C20:1 and cy-C21 fatty acids dominated all of the Aquificales, while the alkyl glycerol ethers were mainly C18:0. These Aquificales biomarkers were major constituents of the lipid extracts of two Octopus Spring samples, a biofilm associated with the siliceous vent walls, and the well-known pink streamer community (PSC). Both the biofilm and the PSC contained mono- and dialkyl glycerol ethers in which C18 and C20 alkyl groups were prevalent. Phospholipid fatty acids included both the Aquificales n-C20:1 and cy-C21, plus a series of iso-branched fatty acids (i-C15:0 to i-C21:0), indicating an additional bacterial component. Biomass and lipids from the PSC were depleted in 13C relative to source water CO2 by 10.9 and 17.2‰, respectively. The C20–21 fatty acids of the PSC were less depleted than the iso-branched fatty acids, 18.4 and 22.6‰, respectively. The biomass of T. ruber grown on CO2 was depleted in 13C by only 3.3‰ relative to C source. In contrast, biomass was depleted by 19.7‰ when formate was the C source. Independent of carbon source, T. ruber lipids were heavier than biomass (+1.3‰). The depletion in the C20–21 fatty acids from the PSC indicates that Thermocrinis biomass must be similarly depleted and too light to be explained by growth on CO2. Accordingly, Thermocrinis in the PSC is likely to have utilized formate, presumably generated in the spring source region. PMID:11679343

  4. Signature lipids and stable carbon isotope analyses of Octopus Spring hyperthermophilic communities compared with those of Aquificales representatives

    NASA Technical Reports Server (NTRS)

    Jahnke, L. L.; Eder, W.; Huber, R.; Hope, J. M.; Hinrichs, K. U.; Hayes, J. M.; Des Marais, D. J.; Cady, S. L.; Summons, R. E.

    2001-01-01

    The molecular and isotopic compositions of lipid biomarkers of cultured Aquificales genera have been used to study the community and trophic structure of the hyperthermophilic pink streamers and vent biofilm from Octopus Spring. Thermocrinis ruber, Thermocrinis sp. strain HI 11/12, Hydrogenobacter thermophilus TK-6, Aquifex pyrophilus, and Aquifex aeolicus all contained glycerol-ether phospholipids as well as acyl glycerides. The n-C(20:1) and cy-C(21) fatty acids dominated all of the Aquificales, while the alkyl glycerol ethers were mainly C(18:0). These Aquificales biomarkers were major constituents of the lipid extracts of two Octopus Spring samples, a biofilm associated with the siliceous vent walls, and the well-known pink streamer community (PSC). Both the biofilm and the PSC contained mono- and dialkyl glycerol ethers in which C(18) and C(20) alkyl groups were prevalent. Phospholipid fatty acids included both the Aquificales n-C(20:1) and cy-C(21), plus a series of iso-branched fatty acids (i-C(15:0) to i-C(21:0)), indicating an additional bacterial component. Biomass and lipids from the PSC were depleted in (13)C relative to source water CO(2) by 10.9 and 17.2 per thousand, respectively. The C(20-21) fatty acids of the PSC were less depleted than the iso-branched fatty acids, 18.4 and 22.6 per thousand, respectively. The biomass of T. ruber grown on CO(2) was depleted in (13)C by only 3.3 per thousand relative to C source. In contrast, biomass was depleted by 19.7 per thousand when formate was the C source. Independent of carbon source, T. ruber lipids were heavier than biomass (+1.3 per thousand). The depletion in the C(20-21) fatty acids from the PSC indicates that Thermocrinis biomass must be similarly depleted and too light to be explained by growth on CO(2). Accordingly, Thermocrinis in the PSC is likely to have utilized formate, presumably generated in the spring source region.

  5. Gene expression profiles of prohibitin in testes of Octopus tankahkeei (ot-phb) revealing its possible role during spermiogenesis.

    PubMed

    Mao, Hai-Tao; Wang, Da-Hui; Lan, Zhou; Zhou, Hong; Yang, Wan-Xi

    2012-05-01

    Prohibitin is essential for intracellular homeostasis and stabilization of mitochondrial respiratory chain complexes. To explore its functions during spermiogenesis of Octopus tankahkeei (O. tankahkeei), we have cloned and sequenced the cDNA of this mammalian PHB homologue (termed ot-PHB) from the testes of O. tankahkeei. The 1165 bp ot-phb cDNA contains a 100 bp 5' UTR, a 882 bp open reading frame and a 183 bp 3' UTR. The putative ot-PHB protein owns a transmembrane domain from 6 to 31 amino acid (aa) and a putative PHB domain from 26 to 178 aa. Protein alignment demonstrated that ot-PHB had 73.3, 73.6, 74.0, 75.1, and 45.4% identity with its homologues in Homo sapiens, Mus muculus, Danio rerio, Xenopus tropicalis and Trypanosoma brucei, respectively. Tissue distribution profile analysis revealed its presence in all the tissues examined. In situ hybridization in spermiogenic cells demonstrated that ot-phb was expressed moderately at the beginning of the spermiogenesis. The abundance of transcripts increased in intermediate spermatids and in drastically remodeling final spermatids. In mature spermatozoa, the residuary transcripts concentrated around the chondriosomal mantle where mitochondria assemble around. In summary, the expression of ot-phb during spermiogenesis implicates a potential function of this protein during mitochondrial ubiquitination. It is the first time to implicate the role of prohibitin in cephalopod spermiogenesis.

  6. Cryptic speciation and the circumpolarity debate: A case study on endemic Southern Ocean octopuses using the COI barcode of life

    NASA Astrophysics Data System (ADS)

    Allcock, A. Louise; Barratt, Iain; Eléaume, Marc; Linse, Katrin; Norman, Mark D.; Smith, Peter J.; Steinke, Dirk; Stevens, Darren W.; Strugnell, Jan M.

    2011-03-01

    Three hundred and fifty specimens of the endemic Southern Ocean octopus genus Pareledone, were sequenced for the barcoding gene COI. Geographic coverage comprised the South Shetland Islands, the Ross Sea, Adélie Land, George V Land, the Weddell Sea, under the site of the former Larsen B ice shelf, Prydz Bay, the South Orkney Islands and the Amundsen Sea. The greatest number of specimens was captured at the three first-mentioned localities. At least 11 species were represented in the samples and the analyses revealed cryptic species. Six species were found to have extended distributions. Circumpolarity is supported for at least one species. Evidence is presented for a barrier to gene flow to the west of the Antarctic Peninsula, with haplotypes of P. aequipapillae becoming progressively more diverse in a clockwise direction from the South Shetland Islands to the Amundsen Sea. This pattern is akin to that seen in ring species, although we suggest that comparatively warm bottom water acts as a physical barrier preventing completion of the ring.

  7. Ontogeny of tetrodotoxin levels in blue-ringed octopuses: maternal investment and apparent independent production in offspring of Hapalochlaena lunulata.

    PubMed

    Williams, Becky L; Hanifin, Charles T; Brodie, Edmund D; Caldwell, Roy L

    2011-01-01

    Many organisms provision offspring with antipredator chemicals. Adult blue-ringed octopuses (Hapalochlaena spp.) harbor tetrodotoxin (TTX), which may be produced by symbiotic bacteria. Regardless of the ultimate source, we find that females invest TTX into offspring and offspring TTX levels are significantly correlated with female TTX levels. Because diversion of TTX to offspring begins during the earliest stages of egg formation, when females are still actively foraging and looking for mates, females may face an evolutionary tradeoff between provisioning larger stores of TTX in eggs and retaining that TTX for their own defense and offense (venom). Given that total TTX levels appear to increase during development and that female TTX levels correlate with those of offspring, investment may be an active adaptive process. Even after eggs have been laid, TTX levels continue to increase, suggesting that offspring or their symbionts begin producing TTX independently. The maternal investment of TTX in offspring of Hapalochlaena spp. represents a rare examination of chemical defenses, excepting ink, in cephalopods.

  8. Conservative nature of oestradiol signalling pathways in the brain lobes of octopus vulgaris involved in reproduction, learning and motor coordination.

    PubMed

    De Lisa, E; Paolucci, M; Di Cosmo, A

    2012-02-01

    Oestradiol plays crucial roles in the mammalian brain by modulating reproductive behaviour, neural plasticity and pain perception. The cephalopod Octopus vulgaris is considered, along with its relatives, to be the most behaviourally advanced invertebrate, although the neurophysiological basis of its behaviours, including pain perception, remain largely unknown. In the present study, using a combination of molecular and imaging techniques, we found that oestradiol up-regulated O. vulgaris gonadotrophin-releasing hormone (Oct-GnRH) and O. vulgaris oestrogen receptor (Oct-ER) mRNA levels in the olfactory lobes; in turn, Oct-ER mRNA was regulated by NMDA in lobes involved in learning and motor coordination. Fluorescence resonance energy transfer analysis revealed that oestradiol binds Oct-ER causing conformational modifications and nuclear translocation consistent with the classical genomic mechanism of the oestrogen receptor. Moreover, oestradiol triggered a calcium influx and cyclic AMP response element binding protein phosphorylation via membrane receptors, providing evidence for a rapid nongenomic action of oestradiol in O. vulgaris. In the present study, we demonstrate, for the first time, the physiological role of oestradiol in the brain lobes of O. vulgaris involved in reproduction, learning and motor coordination.

  9. Identification and Expression of Acetylcholinesterase in Octopus vulgaris Arm Development and Regeneration: a Conserved Role for ACHE?

    PubMed

    Fossati, Sara Maria; Candiani, Simona; Nödl, Marie-Therese; Maragliano, Luca; Pennuto, Maria; Domingues, Pedro; Benfenati, Fabio; Pestarino, Mario; Zullo, Letizia

    2015-08-01

    Acetylcholinesterase (ACHE) is a glycoprotein with a key role in terminating synaptic transmission in cholinergic neurons of both vertebrates and invertebrates. ACHE is also involved in the regulation of cell growth and morphogenesis during embryogenesis and regeneration acting through its non-cholinergic sites. The mollusk Octopus vulgaris provides a powerful model for investigating the mechanisms underlying tissue morphogenesis due to its high regenerative power. Here, we performed a comparative investigation of arm morphogenesis during adult arm regeneration and embryonic arm development which may provide insights on the conserved ACHE pathways. In this study, we cloned and characterized O. vulgaris ACHE, finding a single highly conserved ACHE hydrophobic variant, characterized by prototypical catalytic sites and a putative consensus region for a glycosylphosphatidylinositol (GPI)-anchor attachment at the COOH-terminus. We then show that its expression level is correlated to the stage of morphogenesis in both adult and embryonic arm. In particular, ACHE is localized in typical neuronal sites when adult-like arm morphology is established and in differentiating cell locations during the early stages of arm morphogenesis. This possibility is also supported by the presence in the ACHE sequence and model structure of both cholinergic and non-cholinergic sites. This study provides insights into ACHE conserved roles during processes of arm morphogenesis. In addition, our modeling study offers a solid basis for predicting the interaction of the ACHE domains with pharmacological blockers for in vivo investigations. We therefore suggest ACHE as a target for the regulation of tissue morphogenesis.

  10. Pre- and postsynaptic excitation and inhibition at octopus optic lobe photoreceptor terminals; implications for the function of the 'presynaptic bags'.

    PubMed

    Piscopo, Stefania; Moccia, Francesco; Di Cristo, Carlo; Caputi, Luigi; Di Cosmo, Anna; Brown, Euan R

    2007-10-01

    Synaptic transmission was examined in the plexiform zone of Octopus vulgaris optic lobes using field-potential recording from optic lobe slices. Stimulation of the optic nerve produced pre- and postsynaptic field potentials. Transmission was abolished in calcium-free seawater, L- glutamate or the AMPA/Kainate receptor blocker CNQX (EC(50), 40 microm), leaving an intact presynaptic field potential. ACh markedly reduced or blocked and d-tubocurarine augmented both pre- and postsynaptic field potentials, while alpha-bungarotoxin and atropine were without effect. Paired-pulse stimulation showed short-term depression of pre- and postsynaptic components with a half-time of recovery of approximately 500 ms. The depression was partially relieved in the presence of d-tubocurarine (half-time of recovery, 350 ms). No long-term changes in synaptic strength were induced by repetitive stimulation. A polyclonal antibody raised against a squid glutamate receptor produced positive staining in the third radial layer of the plexiform zone. No positive staining was observed in the other layers. Taking into account previous morphological data and our results, we propose that the excitatory terminations of the photoreceptors are in the innermost layer of the plexiform zone where the transmitter is likely to be glutamate and postsynaptic receptors are AMPA/kainate-like. Thus, the function of the terminal bags is to provide a location for a presynaptic cholinergic inhibitory shunt. The results imply that this arrangement provides a temporal filter for visual processing and enhances the perception of moving vs. stationary objects.

  11. Immunohistochemical observations of methionine-enkephalin and delta opioid receptor in the digestive system of Octopus ocellatus.

    PubMed

    Sha, Ailong; Sun, Hushan; Wang, Yiyan

    2013-02-01

    The study was designed to determine whether methionine-enkephalin (met-Enk) or delta opioid receptor was present in the digestive system of Octopus ocellatus. The results showed that they were both in the bulbus oris, esophagus, crop, stomach, gastric cecum, intestine, posterior salivary glands of O. ocellatus, one of them, met-Enk in the rectum, anterior salivary glands, digestive gland. And the distributions were extensive in the digestive system. Strong or general met-Enk immunoreactivity was observed in the inner epithelial cells of the bulbus oris, esophagus, stomach, gastric cecum, intestine, anterior salivary glands and the adventitia of the intestine and rectum, and so was the delta opioid receptor immunoreactivity in the inner epithelial cells of the bulbus oris, esophagus, and crop, however, they were weak in other parts. Combining with delta opioid receptor, met-Enk may be involved in the regulations of food intake, absorption, movement of gastrointestinal smooth muscle and secretion of digestive gland. The different densities of met-Enk and delta opioid receptor may be related to the different functions in the digestive system of O. ocellatus.

  12. Conformation and structural changes of diblock copolymers with octopus-like micelle formation in the presence of external stimuli

    NASA Astrophysics Data System (ADS)

    Dammertz, K.; Saier, A. M.; Marti, O.; Amirkhani, M.

    2014-04-01

    External stimuli such as vapours and electric fields can be used to manipulate the formation of AB-diblock copolymers on surfaces. We study the conformational variation of PS-b-PMMA (polystyrene-block-poly(methyl methacrylate)), PS and PMMA adsorbed on mica and their response to saturated water or chloroform atmospheres. Using specimens with only partial polymer coverage, new unanticipated effects were observed. Water vapour, a non-solvent for all three polymers, was found to cause high surface mobility. In contrast, chloroform vapour (a solvent for all three polymers) proved to be less efficient. Furthermore, the influence of an additional applied electric field was investigated. A dc field oriented parallel to the sample surface induces the formation of polymer islands which assemble into wormlike chains. Moreover, PS-b-PMMA forms octopus-like micelles (OLMs) on mica. Under the external stimuli mentioned above, the wormlike formations of OLMs are able to align in the direction of the external electric field. In the absence of an electric field, the OLMs disaggregate and exhibit phase separated structures under chloroform vapour.

  13. Reproductive traits of sandbird octopus, Amphioctopus aegina (Gray, 1849) from Mandapam coastal waters (Palk Bay), Southeast Coast of India

    NASA Astrophysics Data System (ADS)

    Ignatius, Boby; Srinivasan, Muthukumarasamy; Balakrishnan, Srinivasan

    2011-09-01

    The sandbird octopus Amphioctopus aegina (Gray, 1849) is one of the important octopod species in trawl catches in Mandapam waters (Palk Bay). The reproductive biology of this species from these waters was studied from October 2001 to September 2002. In the majority of months(Jan-June), the sex ratio was biased towards males. The ratios of males to females increased consistently with respect to weight Total weight at first maturity were 78.78g for females and 40.8 g for males. Four maturity stags were recognized for females and two for males. Maturation and spawning occur all year round, with a peak during October and another peak during January-February. In males, no definite seasonal changes were observed in gonadosomatic index (GSI) values. In females there were two peaks in GSI values during October and January-February. For individuals of a DML range of 67-85 mm fecundity varied between 2,962-8,820 oocytes. The average relative fecundity was estimated at 68 to 83 and the average number oocytes per gram of ovary were 488 to 539.

  14. A new species of pouched octopus, Cistopus Gray, 1849 (Cephalopoda: Octopodidae) from the southwest coast of India.

    PubMed

    Sreeja, Vijayamma; Norman, Mark D; Kumar, Appukuttannair Biju

    2015-12-16

    Octopuses of the genus Cistopus Gray, 1849 are commercially valuable catches in the cephalopod fisheries of India. The primary and unique diagnostic character of this genus is the possession of eight small mucous pouches embedded in the oral faces of the webs between the bases of each arm. Historically only a single species of Cistopus, C. indicus, had been reported from Indian waters. In reviewing the octopod fauna off the Kerala coast, we have detected three species of Cistopus, of which one is described here as a new species. Cistopus platinoidus sp. nov. is distinct from Cistopus species described to date (C. indicus, C. taiwanicus and C. chinensis) on the basis of sucker counts, the number and position of enlarged suckers in males, and presence/absence of a calamus. Our studies of catch composition of Kerala octopod fisheries indicate a higher diversity of target species than previously suspected, including a number of undescribed species. Taxonomic resolution and collation of biological and distributional data are required for effective monitoring and management of these valuable fisheries.

  15. Cholinergic modulation of L-type calcium current in isolated sensory hair cells of the statocyst of octopus, Eledone cirrhosa.

    PubMed

    Chrachri, Abdesslam; Williamson, Roddy

    2004-04-22

    Whole-cell voltage-clamp recordings from dissociated hair cells of the statocyst of octopus, Eledone cirrhosa, demonstrated that application of ACh, carbachol or muscarine (10 microM) reversibly decreased the amplitude of L-type calcium current (I(Ca,L)), while nicotine (10-100 microM) did not have any effect. Furthermore, atropine blocked the effect of ACh and agonists suggesting that ACh reduces I(Ca,L) through activation of muscarinic receptors. Internal dialysis of these cells with guanosine 5'-O-3-thiotriphosphate (GTPgammaS), a non-hydrolysable GTP analogue, mimicked the ACh-induced inhibition of I(Ca,L) and occluded any further ACh-induced inhibition. Internal dialysis of these hair cells with guanosine 5'-O-(2-thiodiphosphate) (GDPbetaS) reduced the ACh-induced inhibition I(Ca,L). The inhibitory effects of ACh were abolished by pre-incubation of these cells with pretussis toxin (PTX) suggesting that ACh-induced inhibition of I(Ca,L) involves a PTX-sensitive G protein pathway.

  16. Structure and function of the carboxyl-terminal oxygen-binding domain from the subunit of Octopus dofleini hemocyanin.

    PubMed

    Miller, K I; van Holde, K E; Toumadje, A; Johnson, W C; Lamy, J

    1988-09-20

    The C-terminal domain, Od-1, of the 7-domain subunit of Octopus dofleini hemocyanin has been prepared by partial trypsinolysis followed by ion-exchange chromatography. It binds oxygen reversibly and is homogeneous in molecular weight. Its physical properties have been compared with those of the subunit. The domain molecular weight is found by sedimentation equilibrium to be 4.7 X 10(4), in excellent agreement with the result recently obtained in our laboratory from cDNA sequencing of this domain [Lang, W. H. (1988) Biochemistry (preceding paper in this issue)]. It has a sedimentation coefficient of 3.8 S. Both the molecular weight and sedimentation coefficient are consistent with the domain constituting approximately one-seventh of the Mr 3.5 X 10(5) subunit. Its amino acid composition and carbohydrate content differ significantly from that of the whole subunit, confirming the heterogeneity in domains previously established on an immunological basis. Circular dichroism predicts similar secondary structure for the domain and subunit. The domain does not self-associate in the presence of Mg2+ but does bind to the whole molecule in a ratio of approximately 1 domain/subunit. The oxygen affinity of this domain is quite low. It shows intrinsic magnesium and Bohr effects similar to those of the whole molecule but of greatly reduced magnitude.

  17. Cloning and sequencing of Octopus dofleini hemocyanin cDNA: derived sequences of functional units Ode and Odf.

    PubMed Central

    Lang, W H; van Holde, K E

    1991-01-01

    A number of additional cDNA clones coding for portions of the very large polypeptide chain of Octopus dofleini hemocyanin were isolated and sequenced. These data reveal two very similar coding sequences, which we have denoted "A-type" and "G-type." We have obtained complete A-type sequences coding for functional units Ode and Odf; consequently a total of three such unit sequences are now known from a single subunit of one molluscan hemocyanin. This presents the opportunity to make sequence comparisons within one hemocyanin subunit. Domains within one subunit show on the average 42% identity in amino acid residues; corresponding functional units from hemocyanins of different species show degrees of identity of 53-75%. Therefore, molluscan hemocyanins already existed before the individual molluscan classes diverged in the early Cambrian. Sequence comparisons of molluscan hemocyanins with arthropodan hemocyanins and tyrosinases allow us to identify the ligands of the "Copper B" site with high probability. Possible ligands for the "Copper A" site are proposed, based on sequence comparisons between molluscan hemocyanins and tyrosinases. Besides two histidine side chains, a methionine side chain might be involved in binding of Copper A, a result not in conflict with spectroscopic studies. Images PMID:1898774

  18. Further approaches to the quaternary structure of octopus hemocyanin: a model based on immunoelectron microscopy and image processing.

    PubMed

    Lamy, J; Gielens, C; Lambert, O; Taveau, J C; Motta, G; Loncke, P; De Geest, N; Préaux, G; Lamy, J

    1993-08-15

    The direction of the polypeptide chains and the location of the functional units in Octopus vulgaris hemocyanin were studied by various methods. Monoclonal antibodies specific for the Ovc (clone Ov409) and Ovg (clone Ov315) functional units produced immunocomplex strings which were examined in the electron microscope. In both cases the immunocomplexes contained more than two hemocyanin molecules in their side view, demonstrating that in the whole hemocyanin neighboring polypeptide chains run in antiparallel directions. The interhemocyanin distances in the immunocomplexes also indicated that Ovg is located inside the cylinder, while Ovc is located in the external layers of functional units. In addition, the fact that the binding point of the Fab arm to the hemocyanin molecule was occasionally visible confirmed the external location of functional unit Ovc. Image processing of the whole hemocyanin cross-linked with dimethyl suberimidate showed that the end-on view is not a perfect cylinder but a regular pentahedron and that the five-arch collar is probably composed of five pairs of functional unit Ovg located inside the cylinder. The accessibility of cross-linked hemocyanin to functional unit-specific polyclonal antibodies, studied in immunoelectrophoresis, showed that Ovb and Ove are highly accessible, while Ovd, Ovf, and Ovg are not. The low accessibility of Ovd may be at least partially explained by its high sugar content which could hamper the accessibility of the antibody to the antigen.

  19. Tailored Synthesis of Octopus-type Janus Nanoparticles for Synergistic Actively-Targeted and Chemo-Photothermal Therapy.

    PubMed

    Zhang, Lingyu; Chen, Yinyin; Li, Zilu; Li, Lu; Saint-Cricq, Philippe; Li, Chunxia; Lin, Jun; Wang, Chungang; Su, Zhongmin; Zink, Jeffrey I

    2016-02-05

    A facile, reproducible, and scalable method was explored to construct uniform Au@poly(acrylic acid) (PAA) Janus nanoparticles (JNPs). The as-prepared JNPs were used as templates to preferentially grow a mesoporous silica (mSiO2 ) shell and Au branches separately modified with methoxy-poly(ethylene glycol)-thiol (PEG) to improve their stability, and lactobionic acid (LA) for tumor-specific targeting. The obtained octopus-type PEG-Au-PAA/mSiO2 -LA Janus NPs (PEG-OJNP-LA) possess pH and NIR dual-responsive release properties. Moreover, DOX-loaded PEG-OJNP-LA, upon 808 nm NIR light irradiation, exhibit obviously higher toxicity at the cellular and animal levels compared with chemotherapy or photothermal therapy alone, indicating the PEG-OJNP-LA could be utilized as a multifunctional nanoplatform for in vitro and in vivo actively-targeted and chemo-photothermal cancer therapy. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Purification and properties of a soluble reduced nicotinamide–adenine dinucleotide (phosphate) dehydrogenase from the hepatopancreas of Octopus vulgaris

    PubMed Central

    Di Prisco, G.; Casola, L.; Giuditta, A.

    1967-01-01

    1. The oxidation of NADH and NADPH catalysed by the soluble supernatant from the hepatopancreas of Octopus vulgaris is due to a single enzyme, which has been purified approximately 100-fold. The enzyme reacts rapidly with potassium ferricyanide, and more slowly with 2,6-dichlorophenol-indophenol. No activity is obtained with oxygen, cytochrome c, lipoic acid, vitamin K1, vitamin K3, ubiquinone-30, p-benzoquinone, 2-p-iodophenyl-3-p-nitrophenyl-5-phenyltetrazolium chloride or methylene blue. 2. GSH, cysteine and mercaptoethanol stimulate the enzymic activity up to fivefold. GSSG is without any apparent effect. When stimulated by GSH the enzyme becomes sensitive to dicoumarol, which produces an inhibition competitive with respect to the activator. 3. The purified enzyme contains an acid-removable flavine component, which has been identified as FMN by spectrofluorimetry and chromatography in three solvent systems. After acid ammonium sulphate treatment the enzymic activity is lost, but it can be almost fully restored by incubation with FMN. FAD produces only a partial reactivation. PMID:4171422

  1. Radio-Protective Effects of Octopus ocellatus Meat Consisted of a Plentiful Taurine Against Damages Caused by Gamma Ray Irradiation.

    PubMed

    Lee, WonWoo; Kim, Eun A; Um, Ju Hyung; Kang, Nalae; Han, Eui Jeong; Oh, Jae Young; Park, Soo Yeon; Jeon, You-Jin; Ahn, Ginnae

    2017-01-01

    Gamma ray irradiation causes immune suppressive responses by inducing oxidative stress such as reduction of cell viability and damages in immune cells. In this present study, we investigated whether Octopus ocellatus meet (OM) consisted of a plentiful taurine has protective effects against damages caused by oxidative stress in murine splenocytes. First of all, we prepared the aqueous extract from OM (OMA) and identified it contained a plentiful taurine content. The result also showed that OMA exhibited the antioxidant activity by scavenging DPPH and ABTS(+) radicals and hydrogen peroxide. In addition, OMA improved the cell viability without cytotoxicity in gamma ray-irradiated murine splenocytes. Moreover, OMA significantly reduced the production of reactive oxygen species (ROS) in gamma ray-irradiated splenocytes. In further study, we identified that OMA protected zebrafish embryo via improving the reduced survival rate and decreasing the formation of deformity caused by the exposure of gamma ray irradiation. Also, OMA decreased the production of NO and ROS in gamma ray-irradiated zebrafish embryos as well as the induction of cell death. In these results, this study suggests that the consumption of taurine-rich foods, such as O. ocellatus, may be useful for the useful material for the protection against oxidative stress.

  2. Aggregation behavior and in vitro biocompatibility study of octopus-shaped macromolecules based on tert-butylcalix[4]arenes.

    PubMed

    Momekova, Denitsa; Budurova, Desislava; Drakalska, Elena; Shenkov, Stoycho; Momekov, Georgi; Trzebicka, Barbara; Lambov, Nikolay; Tashev, Emil; Rangelov, Stanislav

    2012-10-15

    A series of products based on tert-butylcalix[4]arene have been synthesized by anionic polymerization of ethylene oxide. The resulting products are amphiphilic octopus-shaped macromolecules, consisting of a hydrophobic calix[4]arene core and four arms of hydrophilic poly(ethylene oxide) chains. In aqueous solutions the polyoxyethylated tert-butylcalix[4]arenes were found to self-associate above certain CMC determined by dye solubilization technique. The light scattering study reveals that the polyoxyethylated tert-butylcalix[4]arenes form aggregates of narrow size distribution and hydrodynamic diameters ranging from about 155 to 245 nm and aggregation numbers from tens to hundreds macromolecules per particle depending on the degree of polymerization of the PEO chains. An in vitro biocompatibility study showed that the tested compounds are practically devoid of intrinsic cytotoxic and hemolytic effects and moreover they failed to modulate the mitogen-induced interleukin-2 release from the human T-lymphocyte cell line Jurkat E6-1. Taken together the excellent in vitro biocompatibility profile and the favorable physicochemical characteristics of the tested polyoxyethylated calix[4]arenes give us reason to consider them as promising for further evaluation as drug delivery platforms. Copyright © 2012 Elsevier B.V. All rights reserved.

  3. Effect of Different Formulations of Magnesium Chloride Used As Anesthetic Agents on the Performance of the Isolated Heart of Octopus vulgaris.

    PubMed

    Pugliese, Chiara; Mazza, Rosa; Andrews, Paul L R; Cerra, Maria C; Fiorito, Graziano; Gattuso, Alfonsina

    2016-01-01

    Magnesium chloride (MgCl2) is commonly used as a general anesthetic in cephalopods, but its physiological effects including those at cardiac level are not well-characterized. We used an in vitro isolated perfused systemic heart preparation from the common octopus, Octopus vulgaris, to investigate: (a) if in vivo exposure to MgCl2 formulations had an effect on cardiac function in vitro and, if so, could this impact recovery and (b) direct effects of MgCl2 formulations on cardiac function. In vitro hearts removed from animals exposed in vivo to 3.5% MgCl2 in sea water (20 min) or to a mixture of MgCl2+ ethanol (1.12/1%; 20 min) showed cardiac function (heart rate, stroke volume, cardiac output) comparable to hearts removed from animals killed under hypothermia. However, 3.5% MgCl2 (1:1, sea water: distilled water, 20 min) produced a significant impairment of the Frank-Starling response as did 45 min exposure to the MgCl2+ ethanol mixture. Perfusion of the isolated heart with MgCl2± ethanol formulations produced a concentration-related bradycardia (and arrest), a decreased stroke volume and cardiac output indicating a direct effect on the heart. The cardiac effects of MgCl2 are discussed in relation to the involvement of magnesium, sodium, chloride, and calcium ions, exposure time and osmolality of the formulations and the implications for the use of various formulations of MgCl2 as anesthetics in octopus. Overall, provided that the in vivo exposure to 3.5% MgCl2 in sea water or to a mixture of MgCl2+ ethanol is limited to ~20 min, residual effects on cardiac function are unlikely to impact post-anesthetic recovery.

  4. Effect of Different Formulations of Magnesium Chloride Used As Anesthetic Agents on the Performance of the Isolated Heart of Octopus vulgaris

    PubMed Central

    Pugliese, Chiara; Mazza, Rosa; Andrews, Paul L. R.; Cerra, Maria C.; Fiorito, Graziano; Gattuso, Alfonsina

    2016-01-01

    Magnesium chloride (MgCl2) is commonly used as a general anesthetic in cephalopods, but its physiological effects including those at cardiac level are not well-characterized. We used an in vitro isolated perfused systemic heart preparation from the common octopus, Octopus vulgaris, to investigate: (a) if in vivo exposure to MgCl2 formulations had an effect on cardiac function in vitro and, if so, could this impact recovery and (b) direct effects of MgCl2 formulations on cardiac function. In vitro hearts removed from animals exposed in vivo to 3.5% MgCl2 in sea water (20 min) or to a mixture of MgCl2+ ethanol (1.12/1%; 20 min) showed cardiac function (heart rate, stroke volume, cardiac output) comparable to hearts removed from animals killed under hypothermia. However, 3.5% MgCl2 (1:1, sea water: distilled water, 20 min) produced a significant impairment of the Frank-Starling response as did 45 min exposure to the MgCl2+ ethanol mixture. Perfusion of the isolated heart with MgCl2± ethanol formulations produced a concentration-related bradycardia (and arrest), a decreased stroke volume and cardiac output indicating a direct effect on the heart. The cardiac effects of MgCl2 are discussed in relation to the involvement of magnesium, sodium, chloride, and calcium ions, exposure time and osmolality of the formulations and the implications for the use of various formulations of MgCl2 as anesthetics in octopus. Overall, provided that the in vivo exposure to 3.5% MgCl2 in sea water or to a mixture of MgCl2+ ethanol is limited to ~20 min, residual effects on cardiac function are unlikely to impact post-anesthetic recovery. PMID:28082904

  5. First descriptions of dicyemid mesozoans (Dicyemida: Dicyemidae) from Australian octopus (Octopodidae) and cuttlefish (Sepiidae), including a new record of Dicyemennea in Australian waters.

    PubMed

    Catalano, Sarah R

    2013-09-01

    Three new species of dicyemid mesozoans are described for the first time from Australian octopus and cuttlefish species. Dicyemennea floscephalum sp. n. is described from Octopus berrima Stranks et Norman (southern keeled octopus) collected from Spencer Gulf and Gulf St. Vincent, South Australia, Australia and represents the first description of a species of Dicyemennea Whitman, 1883 from Australian waters. Dicyema papuceum sp. n. and D. furuyi sp. n. are described from Sepia papuensis Hoyle (Papuan cuttlefish) collected from Shark Bay, Western Australia, Australia. Dicyemennea floscephalum sp. n. is a medium to large species that reaches approximately 4.9 mm in length. The vermiform stages are characterised by having 23-28 peripheral cells, and a disc-shaped, flower-like calotte in larger individuals. An anterior abortive axial cell is absent in vermiform embryos and verruciform cells were not observed in nematogens and rhombogens. Infusoriform embryos comprise 37 cells; one nucleus is present in each urn cell. Dicyema papuceum sp. n. is a small species that reaches approximately 1.1 mm in length. The vermiform stages are characterised by having 30-33 peripheral cells and a relatively small, cap-shaped calotte. An anterior abortive axial cell is absent in vermiform embryos and verruciform cells were occasionally observed in nematogens. Infusoriform embryos comprise 37 cells; two nuclei are present in each urn cell. Dicyema furuyi sp. n. is a large species that reaches approximately 5.3 mm in length. The vermiform stages are characterised by having 22-24 peripheral cells and an elongate calotte. An anterior abortive axial cell is absent in vermiform embryos and verruciform cells were not observed in nematogens and rhombogens. Infusoriform embryos comprise 37 cells; one nucleus is present in each urn cell. Three secondary nematogens were also observed in the right renal appendages of two host individuals, confirming the occurrence of this form.

  6. Serotonin is a facilitatory neuromodulator of synaptic transmission and "reinforces" long-term potentiation induction in the vertical lobe of Octopus vulgaris.

    PubMed

    Shomrat, T; Feinstein, N; Klein, M; Hochner, B

    2010-08-11

    The modern cephalopod mollusks (coleoids) are considered the most behaviorally advanced invertebrate, yet little is known about the neurophysiological basis of their behaviors. Previous work suggested that the vertical lobe (VL) of cephalopods is a crucial site for the learning and memory components of these behaviors. We are therefore studying the neurophysiology of the VL in Octopus vulgaris and have discovered a robust activity-dependent long-term potentiation (LTP) of the synaptic input to the VL. Moreover, we have shown that the VL and its LTP are involved in behavioral long-term memory acquisition. To advance our understanding of the VL as a learning neural network we explore the possible involvement of neuromodulation in VL function. Here we examine whether the well studied serotonergic modulation in simple models of learning in gastropods mollusks is conserved in the octopus VL. We demonstrate histochemically that the VL is innervated by afferent terminals containing 5-HT immunoreactivity (5-HT-IR). Physiologically, 5-HT has a robust facilitatory effect on synaptic transmission and activity-dependent LTP induction. These results suggest that serotonergic neuromodulation is a part of a reinforcing/reward signaling system conserved in both simple and complex learning systems of mollusks. However, there are notable functional differences. First, the effective concentration of 5-HT in the VL is rather high (100 microM); secondly, only neuropilar regions but not cell bodies in the VL are innervated by terminals containing 5-HT-IR. Thirdly, repetitive or long exposures to 5-HT do not lead to a clear long-term facilitation. We propose that in the octopus VL, while the basic facilitatory properties of molluscan 5-HT system are conserved, the system has adapted to convey signals from other brain areas to reinforce the activity-dependent associations at specific sites in the large connections matrix in the VL. Copyright (c) 2010 IBRO. Published by Elsevier Ltd. All

  7. You Are What You Eat: A Genomic Analysis of the Gut Microbiome of Captive and Wild Octopus vulgaris Paralarvae and Their Zooplankton Prey

    PubMed Central

    Roura, Álvaro; Doyle, Stephen R.; Nande, Manuel; Strugnell, Jan M.

    2017-01-01

    The common octopus (Octopus vulgaris) is an attractive species for aquaculture, however, several challenges inhibit sustainable commercial production. Little is known about the early paralarval stages in the wild, including diet and intestinal microbiota, which likely play a significant role in development and vitality of this important life stage. High throughput sequencing was used to characterize the gastrointestinal microbiome of wild O. vulgaris paralarvae collected from two different upwelling regions off the coast of North West Spain (n = 41) and Morocco (n = 35). These were compared to that of paralarvae reared with Artemia for up to 25 days in captivity (n = 29). In addition, the gastrointestinal microbiome of zooplankton prey (crabs, copepod and krill) was also analyzed to determine if the microbial communities present in wild paralarvae are derived from their diet. Paralarvae reared in captivity with Artemia showed a depletion of bacterial diversity, particularly after day 5, when almost half the bacterial species present on day 0 were lost and two bacterial families (Mycoplasmataceae and Vibrionaceae) dominated the microbial community. In contrast, bacterial diversity increased in wild paralarvae as they developed in the oceanic realm of both upwelling systems, likely due to the exposure of new bacterial communities via ingestion of a wide diversity of prey. Remarkably, the bacterial diversity of recently hatched paralarvae in captivity was similar to that of wild paralarvae and zooplankton, thus suggesting a marked effect of the diet in both the microbial community species diversity and evenness. This study provides a comprehensive overview of the bacterial communities inhabiting the gastrointestinal tract of O. vulgaris paralarvae, and reveals new research lines to challenge the current bottlenecks preventing sustainable octopus aquaculture. PMID:28620315

  8. Sphero-echinocytosis of human red blood cells caused by snake, red-back spider, bee and blue-ringed octopus venoms and its inhibition by snake sera.

    PubMed

    Flachsenberger, W; Leigh, C M; Mirtschin, P J

    1995-06-01

    It was found that bee (Apis mellifera) venom, red-back spider (Latrodectus mactans) venom, blue-ringed octopus (Hapalochlaena maculosa) venom, ten different snake venoms, phospholipase A2 and four snake toxins caused sphero-echinocytosis of human red blood cells at 200 ng/ml. Most venoms and toxins lost the ability to deform human red blood cells when their components of less than mol. wt 10,000 were applied. In a number of cases the sphero-echinocytotic effect was also inhibited by blood sera of Notechis scutatus and Pseudonaja textilis.

  9. Involvement of a Serpin serine protease inhibitor (OoSerpin) from mollusc Octopus ocellatus in antibacterial response.

    PubMed

    Wei, Xiumei; Xu, Jie; Yang, Jianmin; Liu, Xiangquan; Zhang, Ranran; Wang, Weijun; Yang, Jialong

    2015-01-01

    Serpin is an important member of serine protease inhibitors (SPIs), which is capable of regulating proteolytic events and involving in a variety of physiological processes. In present study, a Serpin homolog was identified from Octopus ocellatus (designated as OoSerpin). Full-length cDNA of OoSerpin was of 1735 bp, containing a 5' untranslated region of 214 bp, a 3' UTR of 282 bp, and an open reading frame of 1239 bp. The open reading frame encoded a polypeptide of 412 amino acids which has a predicted molecular weight of 46.5 kDa and an isoelectric point of 8.52. The OoSerpin protein shares 37% sequence identity with other Serpins from Mus musculus (NP_941373) and Ixodes scapularis (XP_002407493). The existence of a conserved SERPIN domain strongly suggested that OoSerpin was a member of the Serpin subfamily. Expression patterns of OoSerpin, both in tissues and towards bacterial stimulation, were then characterized. The mRNA of OoSerpin was constitutively expressed at different levels in all tested tissues of untreated O. ocellatus, including mantle (lowest), muscle, renal sac, gill, hemocyte, gonad, systemic heart, and hepatopancreas (highest). The transcriptional level of OoSerpin was significantly up-regulated (P<0.01) in O. ocellatus upon bacterial challenges with Vibrio anguillarum and Micrococcus luteus, indicating its involvement in the antibacterial immune response. Furthermore, rOoSerpin, the recombinant protein of OoSerpin, exhibited strong abilities to inhibit proteinase activities of trypsin and chymotrypsin as well as the growth of Escherichia coli. Our results demonstrate that OoSerpin is a potential antibacterial factor involved in the immune response of O. ocellatus against bacterial infection.

  10. Comparison of visual and tactile learning in octopus after lesions to one of the two memory systems.

    PubMed

    Bradley, E A; Young, J Z

    1975-01-01

    Sets of animals with lesions to either the vertical lobe or median inferior frontal lobe were trained first visually and then by touch. Lesions of the vertical lobe system did not affect the increase produced by food in tendency to attack a moving figure in the visual field. Any lesion that interrupted the circuit through the vertical lobe greatly impaired the capacity to inhibit attacks on crabs when these attacks resulted in shocks. Removal of the median inferior frontal lobe did not impair this capacity to learn not to attack a crab in the octopus's visual field. The capacity to learn to respond positively to a black disc but to avoid a white one was grossly impaired by an interruption of the vertical lobe circuit. After such operations the animals showed a strong preference for white over black. The capacity to learn to discriminate between black and white was not affected by removal of the median inferior frontal lobe. Animals with interruptions of the vertical lobe circuit could learn to make discrimination between white as a positive figure and black as a negative one, but they made more mistakes than controls. Most mistakes consisted of attacks on the negative (black) figure, but there were also some failures to attack the white. In tactile discrimination between rough and smooth spheres given successively, animals with vertical lobe lesions were, under some circumstances, less accurate than controls. They took more objects than controls. They were less able than controls to reverse the the discrimination. After removal of the median inferior frontal lobe tactile discrimination was greatly impaired. The animals showed a strong preference for rough objects and could not learn to take smooth objects. However, they showed improvement in discrimination when trained with smooth negative and are therefore not wholly incapable of long-term memory storage.

  11. KIFC1-Like Motor Protein Associates with the Cephalopod Manchette and Participates in Sperm Nuclear Morphogenesis in Octopus tankahkeei

    PubMed Central

    Tan, Fu-Qing; Yang, Wan-Xi

    2010-01-01

    Background Nuclear morphogenesis is one of the most fundamental cellular transformations taking place during spermatogenesis. In rodents, a microtubule-based perinuclear structure, the manchette, and a C-terminal kinesin motor KIFC1 are believed to play crucial roles in this process. Spermatogenesis in Octopus tankahkeei is a good model system to explore whether evolution has created a cephalopod prototype of mammalian manchette-based and KIFC1-dependent sperm nuclear shaping machinery. Methodology/Principal Findings We detected the presence of a KIFC1-like protein in the testis, muscle, and liver of O. tankahkeei by Western Blot. Then we tracked its dynamic localization in spermatic cells at various stages using Immunofluorescence and Immunogold Electron Microscopy. The KIFC1-like protein was not expressed at early stages of spermatogenesis when no significant morphological changes occur, began to be present in early spermatid, localized around and in the nucleus of intermediate and late spermatids where the nucleus was dramatically elongated and compressed, and concentrated at one end of final spermatid. Furthermore, distribution of the motor protein during nuclear elongation and condensation overlapped with that of the cephalopod counterpart of manchette at a significant level. Conclusions/Significance The results support the assumption that the protein is actively involved in sperm nuclear morphogenesis in O. tankahkeei possibly through bridging the manchette-like perinuclear microtubules to the nucleus and assisting in the nucleocytoplasmic trafficking of specific cargoes. This study represents the first description of the role of a motor protein in sperm nuclear shaping in cephalopod. PMID:21187923

  12. Degradation of myofibrillar proteins by a calpain-like proteinase in the arm muscle of Octopus vulgaris.

    PubMed

    Hatzizisis, D; Gaitanaki, C; Beis, I

    2000-09-01

    The effects of a calpain-like proteinase (CaDP) isolated from the arm muscle of Octopus vulgaris on the myofibrils and myofibrillar proteins isolated from the same tissue were examined. Our studies clearly showed that treatment of intact myofibrils with CaDP in the presence of 5 mM Ca2+ results in the degradation of the major myofibrillar proteins myosin, paramyosin, and actin. From the isolated alpha- and beta-paramyosins only beta-paramyosin is degraded by CaDP in the presence of 5 mM Ca2+ producing three groups of polypeptides of 80, 75, and 60 kDa, respectively. The degradation rate depends on the proteinase to substrate ratio, temperature, and time of proteolysis and is inhibited by the endogenous CaDP inhibitory factor (CIF), as well as by various known cysteine proteinase inhibitors (E-64, leupeptin, and antipain). From the other myofibrillar proteins examined myosin, but not actin, is degraded by CaDP; myosin heavy chain (MHC, 200 kDa) is degraded by CaDP producing four groups of polypeptides of lower molecular masses (155, 125, 115, and 102 kDa, respectively); the degradation rate depends on the incubation time and the proteinase to substrate ratio. Furthermore, CaDP undergoes limited autolysis in the presence of both the exogenous casein and the endogenous beta-paramyosin producing two large active fragments of 52 and 50.6 kDa, respectively; CIF reversibly inhibits this CaDP autolysis.

  13. Selection and validation of a set of reliable reference genes for quantitative RT-PCR studies in the brain of the Cephalopod Mollusc Octopus vulgaris

    PubMed Central

    Sirakov, Maria; Zarrella, Ilaria; Borra, Marco; Rizzo, Francesca; Biffali, Elio; Arnone, Maria Ina; Fiorito, Graziano

    2009-01-01

    Background Quantitative real-time polymerase chain reaction (RT-qPCR) is valuable for studying the molecular events underlying physiological and behavioral phenomena. Normalization of real-time PCR data is critical for a reliable mRNA quantification. Here we identify reference genes to be utilized in RT-qPCR experiments to normalize and monitor the expression of target genes in the brain of the cephalopod mollusc Octopus vulgaris, an invertebrate. Such an approach is novel for this taxon and of advantage in future experiments given the complexity of the behavioral repertoire of this species when compared with its relatively simple neural organization. Results We chose 16S, and 18S rRNA, actB, EEF1A, tubA and ubi as candidate reference genes (housekeeping genes, HKG). The expression of 16S and 18S was highly variable and did not meet the requirements of candidate HKG. The expression of the other genes was almost stable and uniform among samples. We analyzed the expression of HKG into two different set of animals using tissues taken from the central nervous system (brain parts) and mantle (here considered as control tissue) by BestKeeper, geNorm and NormFinder. We found that HKG expressions differed considerably with respect to brain area and octopus samples in an HKG-specific manner. However, when the mantle is treated as control tissue and the entire central nervous system is considered, NormFinder revealed tubA and ubi as the most suitable HKG pair. These two genes were utilized to evaluate the relative expression of the genes FoxP, creb, dat and TH in O. vulgaris. Conclusion We analyzed the expression profiles of some genes here identified for O. vulgaris by applying RT-qPCR analysis for the first time in cephalopods. We validated candidate reference genes and found the expression of ubi and tubA to be the most appropriate to evaluate the expression of target genes in the brain of different octopuses. Our results also underline the importance of choosing a proper

  14. Enriched Environment Increases PCNA and PARP1 Levels in Octopus vulgaris Central Nervous System: First Evidence of Adult Neurogenesis in Lophotrochozoa.

    PubMed

    Bertapelle, Carla; Polese, Gianluca; Di Cosmo, Anna

    2017-03-02

    Organisms showing a complex and centralized nervous system, such as teleosts, amphibians, reptiles, birds and mammals, and among invertebrates, crustaceans and insects, can adjust their behavior according to the environmental challenges. Proliferation, differentiation, migration, and axonal and dendritic development of newborn neurons take place in brain areas where structural plasticity, involved in learning, memory, and sensory stimuli integration, occurs. Octopus vulgaris has a complex and centralized nervous system, located between the eyes, with a hierarchical organization. It is considered the most "intelligent" invertebrate for its advanced cognitive capabilities, as learning and memory, and its sophisticated behaviors. The experimental data obtained by immunohistochemistry and western blot assay using proliferating cell nuclear antigen and poli (ADP-ribose) polymerase 1 as marker of cell proliferation and synaptogenesis, respectively, reviled cell proliferation in areas of brain involved in learning, memory, and sensory stimuli integration. Furthermore, we showed how enriched environmental conditions affect adult neurogenesis.

  15. Alpha-fucosidase-ganglioside interactions. Action of alpha-L-fucosidase from the hepatopancreas of Octopus vulgaris on a fucose-containing ganglioside (Fuc-GM1).

    PubMed Central

    Masserini, M; Giuliani, A; Venerando, B; Fiorilli, A; D'Aniello, A; Tettamanti, G

    1985-01-01

    alpha-L-Fucosidase, prepared in highly purified form (Mr 70 000-74 000) from Octopus hepatopancreas, was able to hydrolyse a fucose-containing ganglioside, namely Fuc-GM1 (II3NeuAc,IV2Fuc-GgOse4-Cer). The enzyme showed an irregular kinetic behaviour (v/[S] and v/[E] relationships following sigmoidal curves) when working on micellar Fuc-GM1 (Mr of the micelle 500 000), but obeyed regular hyperbolic kinetics when acting on low-Mr substances. It was observed that, on incubation with micellar Fuc-GM1 under the conditions used for the enzyme assay, Octopus alpha-L-fucosidase produced a ganglioside-enzyme complex that was catalytically inactive. This complex had an Mr exceeding 500 000 and a ganglioside/protein ratio of 4:1 (w/w), which is consistent with a stoichiometric combination of one ganglioside micelle with two enzyme molecules. Inactivation of alpha-L-fucosidase by formation of the corresponding complexes was also obtained with micellar gangliosides GM1 (II3NeuAc-GgOse4-Cer), GD1a (II3NeuAc,IV3NeuAc-GgOse4-Cer) and GT1b [II3(NeuAc)2,IV3-NeuAc-GgOse4-Cer], which are not substrates for the enzyme, indicating that the ganglioside micelles per se act as enzyme inhibitors. However, alpha-L-fucosidase easily forms a Fuc-GM1-alpha-L-fucosidase complex, displaying regular Michaelis-Menten kinetics. Therefore the anomalous behaviour exhibited by alpha-L-fucosidase on micellar Fuc-GM1 is likely due to formation of the complex, which separates the fucosyl linkage from the active site of the complexed enzyme, but makes it available to the enzyme in the free form. Images Fig. 2. Fig. 9. PMID:4052012

  16. Alpha-fucosidase-ganglioside interactions. Action of alpha-L-fucosidase from the hepatopancreas of Octopus vulgaris on a fucose-containing ganglioside (Fuc-GM1).

    PubMed

    Masserini, M; Giuliani, A; Venerando, B; Fiorilli, A; D'Aniello, A; Tettamanti, G

    1985-08-01

    alpha-L-Fucosidase, prepared in highly purified form (Mr 70 000-74 000) from Octopus hepatopancreas, was able to hydrolyse a fucose-containing ganglioside, namely Fuc-GM1 (II3NeuAc,IV2Fuc-GgOse4-Cer). The enzyme showed an irregular kinetic behaviour (v/[S] and v/[E] relationships following sigmoidal curves) when working on micellar Fuc-GM1 (Mr of the micelle 500 000), but obeyed regular hyperbolic kinetics when acting on low-Mr substances. It was observed that, on incubation with micellar Fuc-GM1 under the conditions used for the enzyme assay, Octopus alpha-L-fucosidase produced a ganglioside-enzyme complex that was catalytically inactive. This complex had an Mr exceeding 500 000 and a ganglioside/protein ratio of 4:1 (w/w), which is consistent with a stoichiometric combination of one ganglioside micelle with two enzyme molecules. Inactivation of alpha-L-fucosidase by formation of the corresponding complexes was also obtained with micellar gangliosides GM1 (II3NeuAc-GgOse4-Cer), GD1a (II3NeuAc,IV3NeuAc-GgOse4-Cer) and GT1b [II3(NeuAc)2,IV3-NeuAc-GgOse4-Cer], which are not substrates for the enzyme, indicating that the ganglioside micelles per se act as enzyme inhibitors. However, alpha-L-fucosidase easily forms a Fuc-GM1-alpha-L-fucosidase complex, displaying regular Michaelis-Menten kinetics. Therefore the anomalous behaviour exhibited by alpha-L-fucosidase on micellar Fuc-GM1 is likely due to formation of the complex, which separates the fucosyl linkage from the active site of the complexed enzyme, but makes it available to the enzyme in the free form.

  17. Analysis of the 3' untranslated regions of alpha-tubulin and S-crystallin mRNA and the identification of CPEB in dark- and light-adapted octopus retinas.

    PubMed

    Kelly, Shannan; Yamamoto, Hideki; Robles, Laura J

    2008-08-04

    We previously reported the differential expression and translation of mRNA and protein in dark- and light-adapted octopus retinas, which may result from cytoplasmic polyadenylation element (CPE)-dependent mRNA masking and unmasking. Here we investigate the presence of CPEs in alpha-tubulin and S-crystallin mRNA and report the identification of cytoplasmic polyadenylation element binding protein (CPEB) in light- and dark-adapted octopus retinas. 3'-RACE and sequencing were used to isolate and analyze the 3'-UTRs of alpha-tubulin and S-crystallin mRNA. Total retinal protein isolated from light- and dark-adapted octopus retinas was subjected to western blot analysis followed by CPEB antibody detection, PEP-171 inhibition of CPEB, and dephosphorylation of CPEB. The following CPE-like sequence was detected in the 3'-UTR of isolated long S-crystallin mRNA variants: UUUAACA. No CPE or CPE-like sequences were detected in the 3'-UTRs of alpha-tubulin mRNA or of the short S-crystallin mRNA variants. Western blot analysis detected CPEB as two putative bands migrating between 60-80 kDa, while a third band migrated below 30 kDa in dark- and light-adapted retinas. The detection of CPEB and the identification of the putative CPE-like sequences in the S-crystallin 3'-UTR suggest that CPEB may be involved in the activation of masked S-crystallin mRNA, but not in the regulation of alpha-tubulin mRNA, resulting in increased S-crystallin protein synthesis in dark-adapted octopus retinas.

  18. Analysis of the 3’ untranslated regions of α-tubulin and S-crystallin mRNA and the identification of CPEB in dark- and light-adapted octopus retinas

    PubMed Central

    Kelly, Shannan; Yamamoto, Hideki

    2008-01-01

    Purpose We previously reported the differential expression and translation of mRNA and protein in dark- and light-adapted octopus retinas, which may result from cytoplasmic polyadenylation element (CPE)–dependent mRNA masking and unmasking. Here we investigate the presence of CPEs in α-tubulin and S-crystallin mRNA and report the identification of cytoplasmic polyadenylation element binding protein (CPEB) in light- and dark-adapted octopus retinas. Methods 3’-RACE and sequencing were used to isolate and analyze the 3’-UTRs of α-tubulin and S-crystallin mRNA. Total retinal protein isolated from light- and dark-adapted octopus retinas was subjected to western blot analysis followed by CPEB antibody detection, PEP-171 inhibition of CPEB, and dephosphorylation of CPEB. Results The following CPE-like sequence was detected in the 3’-UTR of isolated long S-crystallin mRNA variants: UUUAACA. No CPE or CPE-like sequences were detected in the 3’-UTRs of α-tubulin mRNA or of the short S-crystallin mRNA variants. Western blot analysis detected CPEB as two putative bands migrating between 60-80 kDa, while a third band migrated below 30 kDa in dark- and light-adapted retinas. Conclusions The detection of CPEB and the identification of the putative CPE-like sequences in the S-crystallin 3’-UTR suggest that CPEB may be involved in the activation of masked S-crystallin mRNA, but not in the regulation of α-tubulin mRNA, resulting in increased S-crystallin protein synthesis in dark-adapted octopus retinas. PMID:18682811

  19. The octopus orientation theory.

    PubMed

    Minzlaff, P

    1991-09-01

    Starting a new position is an exciting opportunity that can and should be a positive experience. Listed below are some general concepts that may be applied to help the transition. 1. Volunteer to serve on committees. Don't isolate yourself. Consider being cochair of the United Way or of a fund drive. 2. Keep promises. If you commit to something, do it! No matter how trivial or minor the request, it is important to your credibility that you follow through. If asked when you can accomplish a certain task, evaluate the request and add in a safety margin. Report back to the employee and tell them of your timetable, then deliver it earlier than you promised. Exceed their expectations. 3. Set goals and share them with your staff. Stay focused on these goals, keeping the employees' concentration on the objectives. Peter Druker was on target when he wrote: "Concentration is the key to results, no other principle of effectiveness is violated as constantly today as the basic principle of concentration." 4. Distribute "justice to all." It is critical to your success that you always apply fairness, consistency, or whatever term you associate with equality. Don't establish double standards; making exceptions only leads you down a dark path with no end in sight. 5. "Don't fix it unless it's broken." It is like pulling that tiny thread on your new sweater: once pulled, you immediately realize that you have caused an even bigger problem--one that you can't repair.(ABSTRACT TRUNCATED AT 250 WORDS)

  20. Feeding Relationship between Octopus vulgaris (Cuvier, 1797) Early Life-Cycle Stages and Their Prey in the Western Iberian Upwelling System: Correlation of Reciprocal Lipid and Fatty Acid Contents.

    PubMed

    Lourenço, Sílvia; Roura, Álvaro; Fernández-Reiriz, María-José; Narciso, Luís; González, Ángel F

    2017-01-01

    Under the influence of the Western Iberian upwelling system, the Iberian Atlantic coast holds important hatcheries and recruitment areas for Octopus vulgaris. Recently identified as an octopus hatchery, the Ría de Vigo harbors an important mesozooplankton community that supports O. vulgaris paralarvae during the first days of their planktonic stage. This study represents a preliminary approach to determine the nutritional link between wild O. vulgaris hatchlings, paralarvae and their zooplankton prey in the Ría de Vigo, by analyzing their lipid class content and fatty acid profiles. The results show that octopus hatchlings are richer in structural lipids as phospholipids and cholesterol, while the zooplankton is richer in reserve lipids like triacylglycerol and waxes. Zooplankton samples are also particularly rich in C18:1n9 and 22:6n3 (DHA), that seem to be successfully incorporated by O. vulgaris paralarvae thus resulting in a distinct fatty acid profile to that of the hatchlings. On the other hand, content in C20:4n6 (ARA) is maintained high through development, even though the zooplankton is apparently poorer in this essential fatty acid, confirming its importance for the development of O. vulgaris paralarvae. The content in monounsaturated fatty acids, particularly C18:1n7, and the DHA: EPA ratio are suggested as trophic markers of the diet of O. vulgaris paralarvae.

  1. Biosynthesis of Polyunsaturated Fatty Acids in Octopus vulgaris: Molecular Cloning and Functional Characterisation of a Stearoyl-CoA Desaturase and an Elongation of Very Long-Chain Fatty Acid 4 Protein.

    PubMed

    Monroig, Óscar; de Llanos, Rosa; Varó, Inmaculada; Hontoria, Francisco; Tocher, Douglas R; Puig, Sergi; Navarro, Juan C

    2017-03-21

    Polyunsaturated fatty acids (PUFAs) have been acknowledged as essential nutrients for cephalopods but the specific PUFAs that satisfy the physiological requirements are unknown. To expand our previous investigations on characterisation of desaturases and elongases involved in the biosynthesis of PUFAs and hence determine the dietary PUFA requirements in cephalopods, this study aimed to investigate the roles that a stearoyl-CoA desaturase (Scd) and an elongation of very long-chain fatty acid 4 (Elovl4) protein play in the biosynthesis of essential fatty acids (FAs). Our results confirmed the Octopus vulgaris Scd is a ∆9 desaturase with relatively high affinity towards saturated FAs with ≥ C18 chain lengths. Scd was unable to desaturate 20:1n-15 ((∆5)20:1) suggesting that its role in the biosynthesis of non-methylene interrupted FAs (NMI FAs) is limited to the introduction of the first unsaturation at ∆9 position. Interestingly, the previously characterised ∆5 fatty acyl desaturase was indeed able to convert 20:1n-9 ((∆11)20:1) to (∆5,11)20:2, an NMI FA previously detected in octopus nephridium. Additionally, Elovl4 was able to mediate the production of 24:5n-3 and thus can contribute to docosahexaenoic acid (DHA) biosynthesis through the Sprecher pathway. Moreover, the octopus Elovl4 was confirmed to play a key role in the biosynthesis of very long-chain (>C24) PUFAs.

  2. Biosynthesis of Polyunsaturated Fatty Acids in Octopus vulgaris: Molecular Cloning and Functional Characterisation of a Stearoyl-CoA Desaturase and an Elongation of Very Long-Chain Fatty Acid 4 Protein

    PubMed Central

    Monroig, Óscar; de Llanos, Rosa; Varó, Inmaculada; Hontoria, Francisco; Tocher, Douglas R.; Puig, Sergi; Navarro, Juan C.

    2017-01-01

    Polyunsaturated fatty acids (PUFAs) have been acknowledged as essential nutrients for cephalopods but the specific PUFAs that satisfy the physiological requirements are unknown. To expand our previous investigations on characterisation of desaturases and elongases involved in the biosynthesis of PUFAs and hence determine the dietary PUFA requirements in cephalopods, this study aimed to investigate the roles that a stearoyl-CoA desaturase (Scd) and an elongation of very long-chain fatty acid 4 (Elovl4) protein play in the biosynthesis of essential fatty acids (FAs). Our results confirmed the Octopus vulgaris Scd is a ∆9 desaturase with relatively high affinity towards saturated FAs with ≥ C18 chain lengths. Scd was unable to desaturate 20:1n-15 (∆520:1) suggesting that its role in the biosynthesis of non-methylene interrupted FAs (NMI FAs) is limited to the introduction of the first unsaturation at ∆9 position. Interestingly, the previously characterised ∆5 fatty acyl desaturase was indeed able to convert 20:1n-9 (∆1120:1) to ∆5,1120:2, an NMI FA previously detected in octopus nephridium. Additionally, Elovl4 was able to mediate the production of 24:5n-3 and thus can contribute to docosahexaenoic acid (DHA) biosynthesis through the Sprecher pathway. Moreover, the octopus Elovl4 was confirmed to play a key role in the biosynthesis of very long-chain (>C24) PUFAs. PMID:28335553

  3. Feeding Relationship between Octopus vulgaris (Cuvier, 1797) Early Life-Cycle Stages and Their Prey in the Western Iberian Upwelling System: Correlation of Reciprocal Lipid and Fatty Acid Contents

    PubMed Central

    Lourenço, Sílvia; Roura, Álvaro; Fernández-Reiriz, María-José; Narciso, Luís; González, Ángel F.

    2017-01-01

    Under the influence of the Western Iberian upwelling system, the Iberian Atlantic coast holds important hatcheries and recruitment areas for Octopus vulgaris. Recently identified as an octopus hatchery, the Ría de Vigo harbors an important mesozooplankton community that supports O. vulgaris paralarvae during the first days of their planktonic stage. This study represents a preliminary approach to determine the nutritional link between wild O. vulgaris hatchlings, paralarvae and their zooplankton prey in the Ría de Vigo, by analyzing their lipid class content and fatty acid profiles. The results show that octopus hatchlings are richer in structural lipids as phospholipids and cholesterol, while the zooplankton is richer in reserve lipids like triacylglycerol and waxes. Zooplankton samples are also particularly rich in C18:1n9 and 22:6n3 (DHA), that seem to be successfully incorporated by O. vulgaris paralarvae thus resulting in a distinct fatty acid profile to that of the hatchlings. On the other hand, content in C20:4n6 (ARA) is maintained high through development, even though the zooplankton is apparently poorer in this essential fatty acid, confirming its importance for the development of O. vulgaris paralarvae. The content in monounsaturated fatty acids, particularly C18:1n7, and the DHA: EPA ratio are suggested as trophic markers of the diet of O. vulgaris paralarvae. PMID:28769811

  4. Thermal biology of prey (Melongena corona bispinosa, Strombus pugilis, Callinectes similis, Libinia dubia) and predators (Ocyurus chrysurus, Centropomus undecimalis) of Octopus maya from the Yucatan Peninsula.

    PubMed

    Noyola Regil, Javier; Mascaro, Maite; Díaz, Fernando; Denisse Re, Ana; Sánchez-Zamora, Adolfo; Caamal-Monsreal, Claudia; Rosas, Carlos

    2015-10-01

    On the Yucatan Peninsula there is an upwelling which allows access to a body of cold water that controls temperature in this area. This modulates the ecology and distribution of organisms that inhabit the continental shelf. The objective of this study was to determine the effect of different acclimation temperatures on the thermal biology of prey as mollusc, crustacean (Melongena corona bispinosa, Strombus pugilis, Callinectes similis, Libinia dubia) and predators as fish (Ocyurus chrysurus, Centropomus undecimalis) of Octopus maya. Octopus prey preferred temperatures between 23.5°C and 26.0°C, while predators preferred temperatures 26.4-28.5°C. The species with largest thermal windows were M. corona bispinosa (328.8°C(2)), C. similis (322.8°C(2)), L. dubia (319.2°C(2)), C. undecimalis (288.6°C(2)), O. chrysurus (237.5°C(2)), while the smallest thermal window was for S. pugilis (202.0°C(2)). The acclimation response ratios (ARR) estimated for prey ranged from 0.24-0.55 in animals exposed to CTMax and 0.21-0.65 in those exposed to CTMin. Amongst predators, ARR ranged from 0.30 to 0.60 and 0.41 to 0.53 for animals exposed to CTMax and CTMin, respectively. Correlating the optimal temperature limits of prey and predators with surface temperatures on the continental shelf and those 4m deep showed that the main prey, Callinectes similis and L. dubia, shared a thermal niche and that an increase in temperature could force these species to migrate to other sites to find optimal temperatures for their physiological functions. As a consequence the continental shelf community would undergo a structural change. Predators were found to be near their optimal temperatures in surface temperatures on the continental shelf. We conclude that they would remain in the area in a warming scenario. The size of the thermal window was related to the type of ecosystem inhabited by these species. These ARR intervals allowed us to categorize the species as temperate or tropical

  5. Fatty Acid Profile of Neutral and Polar Lipid Fraction of Wild Eggs and Hatchlings from Wild and Captive Reared Broodstock of Octopus vulgaris.

    PubMed

    Estefanell, Juan; Mesa-Rodríguez, Antonio; Ramírez, Besay; La Barbera, Antonio; Socorro, Juan; Hernandez-Cruz, Carmen María; Izquierdo, María Soledad

    2017-01-01

    The culture of Octopus vulgaris is constrained by unsolved problems in paralarvae rearing, mainly associated to the unknown nutritional requirements of this species in early stages. In this article we studied the fatty acid profile (total, neutral, and polar lipid fractions) in wild eggs and wild hatchlings, collected in Gran Canaria (SW) (Spain) with artificial dens, in comparison to hatchlings obtained in captivity from broodstock fed on trash fish species. Total lipids were 11.5-13.5% dw, with the polar fraction representing a 70.6-75.5% of total lipid, with lower values in wild hatchling in comparison with captive ones. Docosahexaenoic acid (DHA) was the main component in neutral and polar fatty acid profile in all samples, underlying its importance in this species. Decreasing levels of saturates and arachidonic acid (ARA) from wild eggs to hatchlings, mainly associated to the polar fraction, suggest their use during embryonic development. In hatchlings, increasing levels of oleic acid in the neutral fraction and eicosapentaenoic acid (EPA) in the polar fraction, suggests their importance in hatchlings quality. Wild hatchlings showed in the polar fraction higher oleic acid and ARA, and lower DHA/ARA and EPA/ARA ratios in comparison with captive hatchlings, suggesting a difference in paralarvae nutritional status. These results suggest the importance of n-3 highly unsaturated fatty acids (HUFA), oleic acid, and ARA, presented in the adequate lipid fraction, in the diet of broodstock and paralarvae of O. vulgaris.

  6. Surface orientation affects the direction of cone growth by Leptolyngbya sp. strain C1, a likely architect of coniform structures Octopus Spring (Yellowstone National Park).

    PubMed

    Reyes, Kristina; Gonzalez, Nicolas I; Stewart, Joshua; Ospino, Frank; Nguyen, Dickie; Cho, David T; Ghahremani, Nahal; Spear, John R; Johnson, Hope A

    2013-02-01

    Laminated, microbially produced stromatolites within the rock record provide some of the earliest evidence for life on Earth. The chemical, physical, and biological factors that lead to the initiation of these organosedimentary structures and shape their morphology are unclear. Modern coniform structures with morphological features similar to stromatolites are found on the surface of cyanobacterial/microbial mats. They display a vertical element of growth, can have lamination, can be lithified, and observably grow with time. To begin to understand the microbial processes and interactions required for cone formation, we determined the phylogenetic composition of the microbial community of a coniform structure from a cyanobacterial mat at Octopus Spring, Yellowstone National Park, and reconstituted coniform structures in vitro. The 16S rRNA clone library from the coniform structure was dominated by Leptolyngbya sp. Other cyanobacteria and heterotrophic bacteria were present in much lower abundance. The same Leptolyngbya sp. identified in the clone library was also enriched in the laboratory and could produce cones in vitro. When coniform structures were cultivated in the laboratory, the initial incubation conditions were found to influence coniform morphology. In addition, both the angle of illumination and the orientation of the surface affected the angle of cone formation demonstrating how external factors can influence coniform, and likely, stromatolite morphology.

  7. Surface Orientation Affects the Direction of Cone Growth by Leptolyngbya sp. Strain C1, a Likely Architect of Coniform Structures Octopus Spring (Yellowstone National Park)

    PubMed Central

    Reyes, Kristina; Gonzalez, Nicolas I.; Stewart, Joshua; Ospino, Frank; Nguyen, Dickie; Cho, David T.; Ghahremani, Nahal; Spear, John R.

    2013-01-01

    Laminated, microbially produced stromatolites within the rock record provide some of the earliest evidence for life on Earth. The chemical, physical, and biological factors that lead to the initiation of these organosedimentary structures and shape their morphology are unclear. Modern coniform structures with morphological features similar to stromatolites are found on the surface of cyanobacterial/microbial mats. They display a vertical element of growth, can have lamination, can be lithified, and observably grow with time. To begin to understand the microbial processes and interactions required for cone formation, we determined the phylogenetic composition of the microbial community of a coniform structure from a cyanobacterial mat at Octopus Spring, Yellowstone National Park, and reconstituted coniform structures in vitro. The 16S rRNA clone library from the coniform structure was dominated by Leptolyngbya sp. Other cyanobacteria and heterotrophic bacteria were present in much lower abundance. The same Leptolyngbya sp. identified in the clone library was also enriched in the laboratory and could produce cones in vitro. When coniform structures were cultivated in the laboratory, the initial incubation conditions were found to influence coniform morphology. In addition, both the angle of illumination and the orientation of the surface affected the angle of cone formation demonstrating how external factors can influence coniform, and likely, stromatolite morphology. PMID:23241986

  8. Genetic differentiation of octopuses from different habitats near the Korean Peninsula and eastern China based on analysis of the mDNA cytochrome C oxidase 1 gene.

    PubMed

    Kang, J-H; Park, J-Y; Choi, T-J

    2012-11-21

    Distributed along the coastal waters of Korea and China, Octopus minor is found in various habitats, including the mud flats in the southern and western coasts of the Korean Peninsula and the rocky areas around Jeju Island; however, the genetic relationships among the different populations are unknown and have not been studied. We compared 630-nucleotide sequences of the CO1 gene from O. minor specimens collected from five regions around the Korean Peninsula and three regions from eastern China in order to determine population structure and genetic relationships. Based on the sequences at 12 polymorphic sites in this region, 11 haplotypes were identified from 85 specimens. Individuals from Jeju Island had unique haplotypes, including two haplotypes not found in the other populations. Nucleotide and haplotype diversity for all populations ranged from 0.03-0.37 and 0.20-0.64, respectively. Pairwise F(ST) values indicated significant genetic differences in populations from Korea and China. An UPGMA dendrogram showed separation of the eight populations into three clusters; one included only the Jeju population, another included the rest of the Korean populations and some from Dalian, China; a third cluster consisted of two other populations from China. We conclude that there are discrete genetic differences in O. minor from the different habitats, suggesting that the populations should be considered as management units in the ongoing recovery program.