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. ((c) 2006 APA, all rights reserved).

Immunological and Toxinological Responses to Jellyfish Stings

PubMed Central

Tibballs, James; Yanagihara, Angel A.; Turner, Helen C.; Winkel, Ken

2013-01-01

Just over a century ago, animal responses to injections of jellyfish extracts unveiled the phenomenon of anaphylaxis. Yet, until very recently, understanding of jellyfish sting toxicity has remained limited. Upon contact, jellyfish stinging cells discharge complex venoms, through thousands of barbed tubules, into the skin resulting in painful and, potentially, lethal envenomations. This review examines the immunological and toxinological responses to stings by prominent species of jellyfish including Physalia sp. (Portuguese Man-o-War, Blue-bottle), Cubozoan jellyfish including Chironex fleckeri, several Carybdeids including Carybdea arborifera and Alatina moseri, Linuche unguiculta (Thimble jellyfish), a jellyfish responsible for Irukandji syndrome (Carukia barnesi) and Pelagia noctiluca. Jellyfish venoms are composed of potent proteinaceous porins (cellular membrane pore-forming toxins), neurotoxic peptides, bioactive lipids and other small molecules whilst the tubules contain ancient collagens and chitins. We postulate that immunologically, both tubular structural and functional biopolymers as well as venom components can initiate innate, adaptive, as well as immediate and delayed hypersensitivity reactions that may be amenable to topical anti-inflammatory-immunomodifier therapy. The current challenge for immunotoxinologists is to deconstruct the actions of venom components to target therapeutic modalities for sting treatment. PMID:21824077

Optimization and preliminary characterization of venom isolated from 3 medically important jellyfish: the box (Chironex fleckeri), Irukandji (Carukia barnesi), and blubber (Catostylus mosaicus) jellyfish.

PubMed

Wiltshire, C J; Sutherland, S K; Fenner, P J; Young, A R

2000-01-01

To optimize venom extraction and to undertake preliminary biochemical studies of venom from the box jellyfish (Chironex fleckeri), the Irukandji jellyfish (Carukia barnesi), and the blubber jellyfish (Catostylus mosaicus). Lyophilized crude venoms from box jellyfish tentacles and whole Irukandji jellyfish were prepared in water by homogenization, sonication, and rapid freeze thawing. A second technique, consisting of grinding samples with a glass mortar and pestle and using phosphate-buffered saline, was used to prepare crude venom from isolated nematocysts of the box jellyfish, the bells of Irukandji jellyfish, and the oral lobes of blubber jellyfish. Venoms were compared by use of sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and Western blot test. Toxicity of some venoms was determined by intravenous median lethal dose assay in mice. Different venom extraction techniques produced significantly different crude venoms for both box and Irukandji jellyfish. Irukandji and blubber venom SDS-PAGE protein profiles were established for the first time. Analysis of Western blot tests revealed that box jellyfish antivenin reacted specifically with the venom of each jellyfish. Toxicity was found in Irukandji jellyfish venom derived by use of the mortar-and-pestle method, but not in the lyophilized venom. Glass mortar-and-pestle grinding and use of an appropriate buffer was found to be a simple and suitable method for the preparation of venom from each jellyfish species studied. This study contributes to biochemical investigations of jellyfish venoms, particularly the venom of the Irukandji jellyfish, for which there are, to our knowledge, no published studies. It also highlights the importance of optimizing venom extraction as the first step toward understanding the complex biological effects of jellyfish venoms.

Pain from bluebottle jellyfish stings.

PubMed

Li, Li; McGee, Richard G; Webster, Angela C

2015-07-01

An 11-year-old girl presented to the emergency department with severe pain after a jellyfish sting at a New South Wales beach. Bluebottle (Physalia) jellyfish was deemed the most likely cause considering her geographical location. The Australian Resuscitation Council Guideline (2010) suggests immersing in water as hot as can be tolerated for 20 min for treating pain from jellyfish stings. This guideline was written based on past case reports, books and randomised controlled trials (RCTs). We performed a search to assess the most current evidence for relief of pain from Bluebottle jellyfish stings, which yielded two systematic reviews and seven RCTs. Both systematic reviews had similar conclusions, with one of the RCTs used in both reviews showing the most relevance to our presenting patient in terms of demographics, location and jellyfish type. This journal club article is an appraisal of this RCT by Loten et al. and the validity of its conclusion that hot water immersion is most effective for the relief of pain from Bluebottle stings. © 2015 The Authors. Journal of Paediatrics and Child Health © 2015 Paediatrics and Child Health Division (Royal Australasian College of Physicians).

Micro- and Macrorheology of Jellyfish Extracellular Matrix

PubMed Central

Gambini, Camille; Abou, Bérengère; Ponton, Alain; Cornelissen, Annemiek J.M.

2012-01-01

Mechanical properties of the extracellular matrix (ECM) play a key role in tissue organization and morphogenesis. Rheological properties of jellyfish ECM (mesoglea) were measured in vivo at the cellular scale by passive microrheology techniques: microbeads were injected in jellyfish ECM and their Brownian motion was recorded to determine the mechanical properties of the surrounding medium. Microrheology results were compared with macrorheological measurements performed with a shear rheometer on slices of jellyfish mesoglea. We found that the ECM behaved as a viscoelastic gel at the macroscopic scale and as a much softer and heterogeneous viscoelastic structure at the microscopic scale. The fibrous architecture of the mesoglea, as observed by differential interference contrast and scanning electron microscopy, was in accord with these scale-dependent mechanical properties. Furthermore, the evolution of the mechanical properties of the ECM during aging was investigated by measuring microrheological properties at different jellyfish sizes. We measured that the ECM in adult jellyfish was locally stiffer than in juvenile ones. We argue that this stiffening is a consequence of local aggregations of fibers occurring gradually during aging of the jellyfish mesoglea and is enhanced by repetitive muscular contractions of the jellyfish. PMID:22225792

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.

Micro- and macrorheology of jellyfish extracellular matrix.

PubMed

Gambini, Camille; Abou, Bérengère; Ponton, Alain; Cornelissen, Annemiek J M

2012-01-04

Mechanical properties of the extracellular matrix (ECM) play a key role in tissue organization and morphogenesis. Rheological properties of jellyfish ECM (mesoglea) were measured in vivo at the cellular scale by passive microrheology techniques: microbeads were injected in jellyfish ECM and their Brownian motion was recorded to determine the mechanical properties of the surrounding medium. Microrheology results were compared with macrorheological measurements performed with a shear rheometer on slices of jellyfish mesoglea. We found that the ECM behaved as a viscoelastic gel at the macroscopic scale and as a much softer and heterogeneous viscoelastic structure at the microscopic scale. The fibrous architecture of the mesoglea, as observed by differential interference contrast and scanning electron microscopy, was in accord with these scale-dependent mechanical properties. Furthermore, the evolution of the mechanical properties of the ECM during aging was investigated by measuring microrheological properties at different jellyfish sizes. We measured that the ECM in adult jellyfish was locally stiffer than in juvenile ones. We argue that this stiffening is a consequence of local aggregations of fibers occurring gradually during aging of the jellyfish mesoglea and is enhanced by repetitive muscular contractions of the jellyfish. Copyright © 2012 Biophysical Society. Published by Elsevier Inc. All rights reserved.

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.

Recurrent jellyfish blooms are a consequence of global oscillations

PubMed Central

Condon, Robert H.; Duarte, Carlos M.; Pitt, Kylie A.; Robinson, Kelly L.; Lucas, Cathy H.; Sutherland, Kelly R.; Mianzan, Hermes W.; Bogeberg, Molly; Purcell, Jennifer E.; Decker, Mary Beth; Uye, Shin-ichi; Madin, Laurence P.; Brodeur, Richard D.; Haddock, Steven H. D.; Malej, Alenka; Parry, Gregory D.; Eriksen, Elena; Quiñones, Javier; Acha, Marcelo; Harvey, Michel; Arthur, James M.; Graham, William M.

2013-01-01

A perceived recent increase in global jellyfish abundance has been portrayed as a symptom of degraded oceans. This perception is based primarily on a few case studies and anecdotal evidence, but a formal analysis of global temporal trends in jellyfish populations has been missing. Here, we analyze all available long-term datasets on changes in jellyfish abundance across multiple coastal stations, using linear and logistic mixed models and effect-size analysis to show that there is no robust evidence for a global increase in jellyfish. Although there has been a small linear increase in jellyfish since the 1970s, this trend was unsubstantiated by effect-size analysis that showed no difference in the proportion of increasing vs. decreasing jellyfish populations over all time periods examined. Rather, the strongest nonrandom trend indicated jellyfish populations undergo larger, worldwide oscillations with an approximate 20-y periodicity, including a rising phase during the 1990s that contributed to the perception of a global increase in jellyfish abundance. Sustained monitoring is required over the next decade to elucidate with statistical confidence whether the weak increasing linear trend in jellyfish after 1970 is an actual shift in the baseline or part of an oscillation. Irrespective of the nature of increase, given the potential damage posed by jellyfish blooms to fisheries, tourism, and other human industries, our findings foretell recurrent phases of rise and fall in jellyfish populations that society should be prepared to face. PMID:23277544

Recurrent jellyfish blooms are a consequence of global oscillations.

PubMed

Condon, Robert H; Duarte, Carlos M; Pitt, Kylie A; Robinson, Kelly L; Lucas, Cathy H; Sutherland, Kelly R; Mianzan, Hermes W; Bogeberg, Molly; Purcell, Jennifer E; Decker, Mary Beth; Uye, Shin-ichi; Madin, Laurence P; Brodeur, Richard D; Haddock, Steven H D; Malej, Alenka; Parry, Gregory D; Eriksen, Elena; Quiñones, Javier; Acha, Marcelo; Harvey, Michel; Arthur, James M; Graham, William M

2013-01-15

A perceived recent increase in global jellyfish abundance has been portrayed as a symptom of degraded oceans. This perception is based primarily on a few case studies and anecdotal evidence, but a formal analysis of global temporal trends in jellyfish populations has been missing. Here, we analyze all available long-term datasets on changes in jellyfish abundance across multiple coastal stations, using linear and logistic mixed models and effect-size analysis to show that there is no robust evidence for a global increase in jellyfish. Although there has been a small linear increase in jellyfish since the 1970s, this trend was unsubstantiated by effect-size analysis that showed no difference in the proportion of increasing vs. decreasing jellyfish populations over all time periods examined. Rather, the strongest nonrandom trend indicated jellyfish populations undergo larger, worldwide oscillations with an approximate 20-y periodicity, including a rising phase during the 1990s that contributed to the perception of a global increase in jellyfish abundance. Sustained monitoring is required over the next decade to elucidate with statistical confidence whether the weak increasing linear trend in jellyfish after 1970 is an actual shift in the baseline or part of an oscillation. Irrespective of the nature of increase, given the potential damage posed by jellyfish blooms to fisheries, tourism, and other human industries, our findings foretell recurrent phases of rise and fall in jellyfish populations that society should be prepared to face.

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. Copyright © 2016 Elsevier Ltd. All rights reserved.

Ocean acidification alters fish–jellyfish symbiosis

PubMed Central

Nagelkerken, Ivan; Pitt, Kylie A.; Rutte, Melchior D.; Geertsma, Robbert C.

2016-01-01

Symbiotic relationships are common in nature, and are important for individual fitness and sustaining species populations. Global change is rapidly altering environmental conditions, but, with the exception of coral–microalgae interactions, we know little of how this will affect symbiotic relationships. We here test how the effects of ocean acidification, from rising anthropogenic CO2 emissions, may alter symbiotic interactions between juvenile fish and their jellyfish hosts. Fishes treated with elevated seawater CO2 concentrations, as forecast for the end of the century on a business-as-usual greenhouse gas emission scenario, were negatively affected in their behaviour. The total time that fish (yellowtail scad) spent close to their jellyfish host in a choice arena where they could see and smell their host was approximately three times shorter under future compared with ambient CO2 conditions. Likewise, the mean number of attempts to associate with jellyfish was almost three times lower in CO2-treated compared with control fish, while only 63% (high CO2) versus 86% (control) of all individuals tested initiated an association at all. By contrast, none of three fish species tested were attracted solely to jellyfish olfactory cues under present-day CO2 conditions, suggesting that the altered fish–jellyfish association is not driven by negative effects of ocean acidification on olfaction. Because shelter is not widely available in the open water column and larvae of many (and often commercially important) pelagic species associate with jellyfish for protection against predators, modification of the fish–jellyfish symbiosis might lead to higher mortality and alter species population dynamics, and potentially have flow-on effects for their fisheries. PMID:27358374

Ocean acidification alters fish-jellyfish symbiosis.

PubMed

Nagelkerken, Ivan; Pitt, Kylie A; Rutte, Melchior D; Geertsma, Robbert C

2016-06-29

Symbiotic relationships are common in nature, and are important for individual fitness and sustaining species populations. Global change is rapidly altering environmental conditions, but, with the exception of coral-microalgae interactions, we know little of how this will affect symbiotic relationships. We here test how the effects of ocean acidification, from rising anthropogenic CO2 emissions, may alter symbiotic interactions between juvenile fish and their jellyfish hosts. Fishes treated with elevated seawater CO2 concentrations, as forecast for the end of the century on a business-as-usual greenhouse gas emission scenario, were negatively affected in their behaviour. The total time that fish (yellowtail scad) spent close to their jellyfish host in a choice arena where they could see and smell their host was approximately three times shorter under future compared with ambient CO2 conditions. Likewise, the mean number of attempts to associate with jellyfish was almost three times lower in CO2-treated compared with control fish, while only 63% (high CO2) versus 86% (control) of all individuals tested initiated an association at all. By contrast, none of three fish species tested were attracted solely to jellyfish olfactory cues under present-day CO2 conditions, suggesting that the altered fish-jellyfish association is not driven by negative effects of ocean acidification on olfaction. Because shelter is not widely available in the open water column and larvae of many (and often commercially important) pelagic species associate with jellyfish for protection against predators, modification of the fish-jellyfish symbiosis might lead to higher mortality and alter species population dynamics, and potentially have flow-on effects for their fisheries. © 2016 The Author(s).

Jellyfish Body Plans Provide Allometric Advantages beyond Low Carbon Content

PubMed Central

Pitt, Kylie A.; Duarte, Carlos M.; Lucas, Cathy H.; Sutherland, Kelly R.; Condon, Robert H.; Mianzan, Hermes; Purcell, Jennifer E.; Robinson, Kelly L.; Uye, Shin-Ichi

2013-01-01

Jellyfish form spectacular blooms throughout the world’s oceans. Jellyfish body plans are characterised by high water and low carbon contents which enables them to grow much larger than non-gelatinous animals of equivalent carbon content and to deviate from non-gelatinous pelagic animals when incorporated into allometric relationships. Jellyfish have, however, been argued to conform to allometric relationships when carbon content is used as the metric for comparison. Here we test the hypothesis that differences in allometric relationships for several key functional parameters remain for jellyfish even after their body sizes are scaled to their carbon content. Data on carbon and nitrogen contents, rates of respiration, excretion, growth, longevity and swimming velocity of jellyfish and other pelagic animals were assembled. Allometric relationships between each variable and the equivalent spherical diameters of jellyfish and other pelagic animals were compared before and after sizes of jellyfish were standardised for their carbon content. Before standardisation, the slopes of the allometric relationships for respiration, excretion and growth were the same for jellyfish and other pelagic taxa but the intercepts differed. After standardisation, slopes and intercepts for respiration were similar but excretion rates of jellyfish were 10× slower, and growth rates 2× faster than those of other pelagic animals. Longevity of jellyfish was independent of size. The slope of the allometric relationship of swimming velocity of jellyfish differed from that of other pelagic animals but because they are larger jellyfish operate at Reynolds numbers approximately 10× greater than those of other pelagic animals of comparable carbon content. We conclude that low carbon and high water contents alone do not explain the differences in the intercepts or slopes of the allometric relationships of jellyfish and other pelagic animals and that the evolutionary longevity of jellyfish and

Jellyfish body plans provide allometric advantages beyond low carbon content.

PubMed

Pitt, Kylie A; Duarte, Carlos M; Lucas, Cathy H; Sutherland, Kelly R; Condon, Robert H; Mianzan, Hermes; Purcell, Jennifer E; Robinson, Kelly L; Uye, Shin-Ichi

2013-01-01

Jellyfish form spectacular blooms throughout the world's oceans. Jellyfish body plans are characterised by high water and low carbon contents which enables them to grow much larger than non-gelatinous animals of equivalent carbon content and to deviate from non-gelatinous pelagic animals when incorporated into allometric relationships. Jellyfish have, however, been argued to conform to allometric relationships when carbon content is used as the metric for comparison. Here we test the hypothesis that differences in allometric relationships for several key functional parameters remain for jellyfish even after their body sizes are scaled to their carbon content. Data on carbon and nitrogen contents, rates of respiration, excretion, growth, longevity and swimming velocity of jellyfish and other pelagic animals were assembled. Allometric relationships between each variable and the equivalent spherical diameters of jellyfish and other pelagic animals were compared before and after sizes of jellyfish were standardised for their carbon content. Before standardisation, the slopes of the allometric relationships for respiration, excretion and growth were the same for jellyfish and other pelagic taxa but the intercepts differed. After standardisation, slopes and intercepts for respiration were similar but excretion rates of jellyfish were 10× slower, and growth rates 2× faster than those of other pelagic animals. Longevity of jellyfish was independent of size. The slope of the allometric relationship of swimming velocity of jellyfish differed from that of other pelagic animals but because they are larger jellyfish operate at Reynolds numbers approximately 10× greater than those of other pelagic animals of comparable carbon content. We conclude that low carbon and high water contents alone do not explain the differences in the intercepts or slopes of the allometric relationships of jellyfish and other pelagic animals and that the evolutionary longevity of jellyfish and

Immunostimulatory effects of collagen from jellyfish in vivo.

PubMed

Morishige, Hitoshi; Sugahara, Takuya; Nishimoto, Sogo; Muranaka, Ayako; Ohno, Fumi; Shiraishi, Ryusuke; Doi, Mikiharu

2011-10-01

We focused on the biological activity of the collagen extracts obtained from the giant edible jellyfish, Nemopilema nomurai. Jellyfish collagen extracts stimulates the production of immunoglobulins (Igs) and cytokines by human hybridoma cells and human peripheral blood lymphocytes. Therefore, we examined the immunoregulatory function of jellyfish collagen extracts in mice. Intake of jellyfish collagen extracts facilitated the Ig production activity of lymphocytes from spleen and Peyer's patch. Furthermore, the levels of Igs in the serum clearly increased after the administration of jellyfish collagen extracts. Intake of bovine collagen from Achilles' tendon also activated lymphocytes activity in mice. The activity of total and antigen-specific Ig production in splenocytes from OVA-challenged mice was also enhanced by collagen intake. However, the total and OVA-specific IgE levels in the serum were not affected by the collagen intake. These results suggested that jellyfish collagen extracts stimulates an immune response in vivo, without inducing allergic complications.

[Causes of jellyfish blooms and their influence on marine environment].

PubMed

Qu, Chang-feng; Song, Jin-ming; Li, Ning

2014-12-01

Jellyfish blooms have damaged the normal composition and function of marine ecosystem and ecological environments, which have been one of the new marine ecological disasters. In this study, we summarized the possible inducements of jellyfish blooms, and the influences of jellyfish blooms on biogenic elements, dissolved oxygen, seawater acidity and biological community were discussed emphatically. The results showed that jellyfish blooms had a close contact with its physiological structure and life history, which had favorable characteristics including simple body struc- ture, rapid growth, thriving reproduction and short generation interval to tolerate harsh environment better. Jellyfish abundance increased rapidly when it encountered suitable conditions. The temperature variations of seawater might be the major inducing factor which could result in jellyfish blooms. Jellyfish blooms may benefit from warmer temperature that could increase the food availability of jellyfish and promote jellyfish reproduction, especially for warm temperate jellyfish species. Eutrophication, climate change, overfishing, alien invasions and habitat modification were all possible important contributory factors of jellyfish blooms. Jellyfish could significantly influence the form distribution and biogeochemical cycling of biogenic elements. Jellyfish excreted NH4+ and P04(3-) at a rate of 59.1-91.5 micromol N x kg(-1) x h(-1) and 1.1-1.8 micromol P x kg(-1) x h(-1), which could meet about 8%-10% and 21.6% of the phytoplankton primary production requirement of N and P, respectively. Live jellyfish released dissolved organic carbon (DOC) at a rate of 1.0 micromol C x g(-1) x d(-1). As jellyfish decomposing, the effluxes of total N and total P were 4000 micromol N x kg(-1) x d(-1) and 120 micromol P x kg(-1) x d(-1), respectively, while the efflux of DOC reached 30 micromol C x g(-1) x d(-1). Jellyfish decomposition could cause seawater acidification and lowered level of dissolved oxygen

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.

From Undersea to Outer Space: The STS-40 Jellyfish Experiment

NASA Technical Reports Server (NTRS)

1994-01-01

This is an educational production featuring 'Ari', animated jellyfish who recounts his journey into space. Jellyfish were flown aboard the shuttle to study the effects of microgravity on living organisms. Topics Ari explores are: microgravity, life sciences, similarities between jellyfish and humans, and the life cycle and anatomy of a jellyfish.

Indonesian jellyfish as potential for raw materials of food and drug

NASA Astrophysics Data System (ADS)

Yusuf, S.; Fahmid, I. M.; Abdullah, N.; Zulhaeriah

2018-05-01

Jellyfish used to be considered as a pest of fish and a nuisance to fishing operations. Yet, forty years ago this jellyfish was found to be materials of food, medicine and cosmetics and the utilization of jellyfish is now familiar in Indonesia after being imported by China and Japan industry. This study aims to determine the potential development of jellyfish commodities as food and drugs from Indonesia with the target to improve the welfare of fishermen. This research used methods of rapid observation, limited interview, processing with immersion experiment and desiccation. In addition, various literatures were also used to enrich the knowledge about jellyfish business. Observation showed that the appearance of jellyfish in Indonesian waters varies based on the fertility of the waters affected by oceanographic conditions. Jellyfish contains low calorie and fat content, high protein and minerals as well as total collagen. Thus, jellyfish is a nutritious food source to be developed into food supplements, nutricosmetics and functional foods. Due to its large size, the jellyfish from Bunyu Island is more viable than jellyfish from Suppa Pinrang to be exported as raw material. Therefore, the manufacture of food and medicines from jellyfish materials is possible to be done in Indonesia.

AN ADULT CASE OF ANAPHYLAXIS CAUSED BY ALLERGY TO JELLYFISH.

PubMed

Suzuki, Shintaro; Miyata, Yoshito; Jinno, Megumi; Kishino, Yasunari; Homma, Tetsuya; Ota, Shin; Tanaka, Akihiko; Yokoe, Takuya; Ohnishi, Tsukasa; Sagara, Hironori; Kurata, Naomi; Shimakura, Kuniyoshi; Kurose, Kouichi

2017-01-01

A 35-year-old female, professional diver, reported nausea, vomiting, and systemic hives 20 to 30 minutes after ingestion of antipasto made with jellyfish. Patient reported prior episodes of swelling after stings from several different creatures, including jelly fish. She also developed a systemic allergic reaction after sting from an unknown creature while diving. On the initial visit to our hospital, serum total IgE level was 545IU/ml. We extracted crude allergen from jellyfish and evaluated allergen specific IgE antibody levels using ELISA. Patient samples showed higher levels of jellyfish-derived allergen specific IgE than healthy control samples. Basophils were isolated from the peripheral blood of patient. Stimulation with jellyfish-derived allergen showed expression of surface antigens on basophils increased in a concentration-dependent manner. Methods using sodium dodecyl sulfate poly acrylamide gel electrophoresis and immunoblotting showed acid-soluble collagen fraction from jellyfish contained above 250kDa weighed protein that may have caused this current event. A provocation test using jellyfish samples was not performed due to risk of anaphylactic shock. The patient was diagnosed with a jellyfish allergy due to IgE mediated anaphylaxis after ingestion. She was asked to refrain from consuming any food containing jellyfish. IgE-mediated food allergy caused by jellyfish is rare worldwide. Collagen was speculated to be an allergen in this study. Additional study to detect specific allergens related to jellyfish allergy would be particularly useful to specify disease phenotypes and individual care in future.

Jellyfish Patch Detecting Using Low Latitude Remote Sensing System

NASA Astrophysics Data System (ADS)

Lee, J. S.; Jo, Y. H.

2015-12-01

Jellyfish can be asexual and sexual reproduction depending on the environment, and it has excellent environmental adaptability and reproduction than other sea creatures. If the marine environment become worse, jellyfish can take advantage in the competition for survival. Marine environmental changes caused by rapid climate change, dyke construction and land reclamation will increase the amount of jellyfish and as a result can lead to a various social and economic problems. In this study, jellyfish were observed in coastal area using a low-altitude Helikite remote sensing system for the first time. Helikite is a type of helium balloon plus a kite that can get the data with optical sensors for the desired spatial resolutions by adjusting the altitudes. In addition, it has an advantage that can monitor any objects for a long time at one place as long as the electric power and helium last. In this study, we observed the jellyfish patches using a digital camera in the Chesapeake Bay and estimate populations and size of jellyfish patches through image processing. Research results suggests that we can have long-term real-time observations for not only jellyfish, but also other harmful marine creatures.

Environmental DNA reflects spatial and temporal jellyfish distribution

PubMed Central

Fukuda, Miho; Katsuhara, Koki R.; Fujiwara, Ayaka; Hidaka, Shunsuke; Yamamoto, Satoshi; Takahashi, Kohji; Masuda, Reiji

2017-01-01

Recent development of environmental DNA (eDNA) analysis allows us to survey underwater macro-organisms easily and cost effectively; however, there have been no reports on eDNA detection or quantification for jellyfish. Here we present the first report on an eDNA analysis of marine jellyfish using Japanese sea nettle (Chrysaora pacifica) as a model species by combining a tank experiment with spatial and temporal distribution surveys. We performed a tank experiment monitoring eDNA concentrations over a range of time intervals after the introduction of jellyfish, and quantified the eDNA concentrations by quantitative real-time PCR. The eDNA concentrations peaked twice, at 1 and 8 h after the beginning of the experiment, and became stable within 48 h. The estimated release rates of the eDNA in jellyfish were higher than the rates previously reported in fishes. A spatial survey was conducted in June 2014 in Maizuru Bay, Kyoto, in which eDNA was collected from surface water and sea floor water samples at 47 sites while jellyfish near surface water were counted on board by eye. The distribution of eDNA in the bay corresponded with the distribution of jellyfish inferred by visual observation, and the eDNA concentration in the bay was ~13 times higher on the sea floor than on the surface. The temporal survey was conducted from March to November 2014, in which jellyfish were counted by eye every morning while eDNA was collected from surface and sea floor water at three sampling points along a pier once a month. The temporal fluctuation pattern of the eDNA concentrations and the numbers of observed individuals were well correlated. We conclude that an eDNA approach is applicable for jellyfish species in the ocean. PMID:28245277

Not all jellyfish are equal: isotopic evidence for inter- and intraspecific variation in jellyfish trophic ecology

PubMed Central

Fleming, Nicholas E.C.; Newton, Jason; Houghton, Jonathan D.R.

2015-01-01

Jellyfish are highly topical within studies of pelagic food-webs and there is a growing realisation that their role is more complex than once thought. Efforts being made to include jellyfish within fisheries and ecosystem models are an important step forward, but our present understanding of their underlying trophic ecology can lead to their oversimplification in these models. Gelatinous zooplankton represent a polyphyletic assemblage spanning >2,000 species that inhabit coastal seas to the deep-ocean and employ a wide variety of foraging strategies. Despite this diversity, many contemporary modelling approaches include jellyfish as a single functional group feeding at one or two trophic levels at most. Recent reviews have drawn attention to this issue and highlighted the need for improved communication between biologists and theoreticians if this problem is to be overcome. We used stable isotopes to investigate the trophic ecology of three co-occurring scyphozoan jellyfish species (Aurelia aurita, Cyanea lamarckii and C. capillata) within a temperate, coastal food-web in the NE Atlantic. Using information on individual size, time of year and δ13C and δ15N stable isotope values, we examined: (1) whether all jellyfish could be considered as a single functional group, or showed distinct inter-specific differences in trophic ecology; (2) Were size-based shifts in trophic position, found previously in A. aurita, a common trait across species?; (3) When considered collectively, did the trophic position of three sympatric species remain constant over time? Differences in δ15N (trophic position) were evident between all three species, with size-based and temporal shifts in δ15N apparent in A. aurita and C. capillata. The isotopic niche width for all species combined increased throughout the season, reflecting temporal shifts in trophic position and seasonal succession in these gelatinous species. Taken together, these findings support previous assertions that

Not all jellyfish are equal: isotopic evidence for inter- and intraspecific variation in jellyfish trophic ecology.

PubMed

Fleming, Nicholas E C; Harrod, Chris; Newton, Jason; Houghton, Jonathan D R

2015-01-01

Jellyfish are highly topical within studies of pelagic food-webs and there is a growing realisation that their role is more complex than once thought. Efforts being made to include jellyfish within fisheries and ecosystem models are an important step forward, but our present understanding of their underlying trophic ecology can lead to their oversimplification in these models. Gelatinous zooplankton represent a polyphyletic assemblage spanning >2,000 species that inhabit coastal seas to the deep-ocean and employ a wide variety of foraging strategies. Despite this diversity, many contemporary modelling approaches include jellyfish as a single functional group feeding at one or two trophic levels at most. Recent reviews have drawn attention to this issue and highlighted the need for improved communication between biologists and theoreticians if this problem is to be overcome. We used stable isotopes to investigate the trophic ecology of three co-occurring scyphozoan jellyfish species (Aurelia aurita, Cyanea lamarckii and C. capillata) within a temperate, coastal food-web in the NE Atlantic. Using information on individual size, time of year and δ (13)C and δ (15)N stable isotope values, we examined: (1) whether all jellyfish could be considered as a single functional group, or showed distinct inter-specific differences in trophic ecology; (2) Were size-based shifts in trophic position, found previously in A. aurita, a common trait across species?; (3) When considered collectively, did the trophic position of three sympatric species remain constant over time? Differences in δ (15)N (trophic position) were evident between all three species, with size-based and temporal shifts in δ (15)N apparent in A. aurita and C. capillata. The isotopic niche width for all species combined increased throughout the season, reflecting temporal shifts in trophic position and seasonal succession in these gelatinous species. Taken together, these findings support previous assertions

[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.

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

Eating jellyfish: safety, chemical and sensory properties.

PubMed

Raposo, António; Coimbra, Alice; Amaral, Luís; Gonçalves, Amparo; Morais, Zilda

2018-01-31

People's preference for fish with a high trophic level, like Atlantic cod and tuna, leads to a large food footprint. Responsible seafood consumption should include underutilised local products; hence the culinary use of edible jellyfish can be an effective contribution. The present work focused on Catostylus tagi to contribute to the consumption of edible jellyfish in the West. A questionnaire conducted with 192 young people showed an interest in tasting jellyfish-based food (64.6%). The resulting product, obtained by an alternative cooking process to traditional Asian ones, was chemically characterised and underwent microbiological and heavy metals control. The results indicated its non-toxicity. Patients who were allergic to seafood as well as non-allergic volunteers revealed no allergic reaction to the jellyfish umbrella product (intakes up to 5 mg/kg body weight and 8 mg/kg, respectively). Seafood-trained panellists defined the product's main impact on the mouth as freshness (72 mg/kg body weight). The preliminary snack, a pâté, was positively accepted by allergic (7 in 9; n = 20) and non-allergic volunteers (6 in 7; n = 21). The present study confirmed that jellyfish intake is safe, even for allergic individuals, and its organoleptic properties were accepted by the study population. © 2018 Society of Chemical Industry. © 2018 Society of Chemical Industry.

Uniocular and binocular fields of rotation measures: Octopus versus Goldmann.

PubMed

Rowe, Fiona J; Hanif, Sahira

2011-06-01

To compare the range of ocular rotations measured by Octopus versus Goldmann perimetry. Forty subjects (20 controls and 20 patients with impaired ocular movements) were prospectively recruited, age range 21-83 years. Range of uniocular rotations was measured in six vectors corresponding to extraocular muscle actions: 0°, 67°, 141°, 180°, 216°, 293°. Fields of binocular single vision were assessed at 30° intervals. Vector measurements were utilised to calculate an area score for the field of uniocular rotations or binocular field of single vision. Two test speeds were used for Octopus testing: 3°/ and 10°/second. Test duration was two thirds quicker for Octopus 10°/second than for 3°/second stimulus speed, and slightly quicker for Goldmann. Mean area for control subjects for uniocular field was 7910.45 degrees(2) for Goldmann, 7032.14 for Octopus 3°/second and 7840.66 for Octopus 10°/second. Mean area for patient subjects of right uniocular field was 8567.21 degrees(2) for Goldmann, 5906.72 for Octopus 3°/second and 8806.44 for Octopus 10°/second. Mean area for left uniocular field was 8137.49 degrees(2) for Goldmann, 8127.9 for Octopus 3°/second and 8950.54 for Octopus 10°/second. Range of measured rotation was significantly larger for Octopus 10°/second speed. Our results suggest that the Octopus perimeter is an acceptable alternative method of assessment for uniocular ductions and binocular field of single vision. Speed of stimulus significantly alters test duration for Octopus perimetry. Comparisons of results from both perimeters show that quantitative measurements differ, although qualitatively the results are similar. Differences per mean vectors were less than 5° (within clinically accepted variances) for both controls and patients when comparing Goldmann to Octopus 10°/second speed. However, differences were almost 10° for the patient group when comparing Goldmann to Octopus 3°/second speed. Thus, speed of stimulus must be considered

The global susceptibility of coastal forage fish to competition by large jellyfish

PubMed Central

Mariani, Patrizio

2016-01-01

Competition between large jellyfish and forage fish for zooplankton prey is both a possible cause of jellyfish increases and a concern for the management of marine ecosystems and fisheries. Identifying principal factors affecting this competition is therefore important for marine management, but the lack of both good quality data and a robust theoretical framework have prevented general global analyses. Here, we present a general mechanistic food web model that considers fundamental differences in feeding modes and predation pressure between fish and jellyfish. The model predicts forage fish dominance at low primary production, and a shift towards jellyfish with increasing productivity, turbidity and fishing. We present an index of global ecosystem susceptibility to shifts in fish–jellyfish dominance that compares well with data on jellyfish distributions and trends. The results are a step towards better understanding the processes that govern jellyfish occurrences globally and highlight the advantage of considering feeding traits in ecosystem models. PMID:28120793

The global susceptibility of coastal forage fish to competition by large jellyfish.

PubMed

Schnedler-Meyer, Nicolas Azaña; Mariani, Patrizio; Kiørboe, Thomas

2016-11-16

Competition between large jellyfish and forage fish for zooplankton prey is both a possible cause of jellyfish increases and a concern for the management of marine ecosystems and fisheries. Identifying principal factors affecting this competition is therefore important for marine management, but the lack of both good quality data and a robust theoretical framework have prevented general global analyses. Here, we present a general mechanistic food web model that considers fundamental differences in feeding modes and predation pressure between fish and jellyfish. The model predicts forage fish dominance at low primary production, and a shift towards jellyfish with increasing productivity, turbidity and fishing. We present an index of global ecosystem susceptibility to shifts in fish-jellyfish dominance that compares well with data on jellyfish distributions and trends. The results are a step towards better understanding the processes that govern jellyfish occurrences globally and highlight the advantage of considering feeding traits in ecosystem models. © 2016 The Author(s).

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

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.

Dermoscopic Findings of Jellyfish Stings Caused by Pelagia noctiluca.

PubMed

Del Pozo, L J; Knöpfel, N; Martín-Santiago, A; Escudero-Góngora, M M; Saus, C; Izquierdo-Herce, N; Bauzà-Alonso, A

2016-01-01

Jellyfish are free-living members of the phylum Cnidaria who share a specialized stinging cell, the cnidocyte. Pelagia noctiluca is the most frequent and toxic jellyfish species found in the Balearic beaches and cnidocytes are arranged in pigmented clusters called "warts". Dermoscopy continues to expand its use much beyond the pigmentary lesions and to date, there is no data regarding dermoscopic findings in jellyfish stings. The aim of the present work was to study the dermoscopic findings of jellyfish stings in the island of Mallorca. We retrospectively reviewed the clinical and dermoscopic images of 25 episodes of jellyfish stings caused by P. noctiluca that occurred between 2009 and 2015. Overall, the following dermoscopic features were found: brown dots (84%), pinkish hue (56%), pinpoint brown crusts (44%), scale-crust (40%), brown "Chinese characters pattern" (32%), "serpentine" ulceration (28%), linear purpura (20%), and whitish-yellow crusts (15%). Vessels were mainly dotted (36%) or reticular (16%). Scale-crust, serpentine ulceration and pinkish hue were significantly more frequent in lesions older than 2 days. Our study identifies 4 dermoscopic features that may represent the contact with P. noctiluca cnidocytes: brown dots, brown "Chinese characters pattern", pinpoint brown crusts and whitish-yellow crusts. A peculiar finding of "serpentine ulceration" with brown dots would be very suggestive of P. noctiluca sting. We believe dermoscopy is a valuable tool in the diagnosis of jellyfish stings when a clear history of contact is lacking. Further studies are needed to validate our findings in other jellyfish species. Copyright © 2016 AEDV. Published by Elsevier España, S.L.U. All rights reserved.

Deterministic Factors Overwhelm Stochastic Environmental Fluctuations as Drivers of Jellyfish Outbreaks.

PubMed

Benedetti-Cecchi, Lisandro; Canepa, Antonio; Fuentes, Veronica; Tamburello, Laura; Purcell, Jennifer E; Piraino, Stefano; Roberts, Jason; Boero, Ferdinando; Halpin, Patrick

2015-01-01

Jellyfish outbreaks are increasingly viewed as a deterministic response to escalating levels of environmental degradation and climate extremes. However, a comprehensive understanding of the influence of deterministic drivers and stochastic environmental variations favouring population renewal processes has remained elusive. This study quantifies the deterministic and stochastic components of environmental change that lead to outbreaks of the jellyfish Pelagia noctiluca in the Mediterranen Sea. Using data of jellyfish abundance collected at 241 sites along the Catalan coast from 2007 to 2010 we: (1) tested hypotheses about the influence of time-varying and spatial predictors of jellyfish outbreaks; (2) evaluated the relative importance of stochastic vs. deterministic forcing of outbreaks through the environmental bootstrap method; and (3) quantified return times of extreme events. Outbreaks were common in May and June and less likely in other summer months, which resulted in a negative relationship between outbreaks and SST. Cross- and along-shore advection by geostrophic flow were important concentrating forces of jellyfish, but most outbreaks occurred in the proximity of two canyons in the northern part of the study area. This result supported the recent hypothesis that canyons can funnel P. noctiluca blooms towards shore during upwelling. This can be a general, yet unappreciated mechanism leading to outbreaks of holoplanktonic jellyfish species. The environmental bootstrap indicated that stochastic environmental fluctuations have negligible effects on return times of outbreaks. Our analysis emphasized the importance of deterministic processes leading to jellyfish outbreaks compared to the stochastic component of environmental variation. A better understanding of how environmental drivers affect demographic and population processes in jellyfish species will increase the ability to anticipate jellyfish outbreaks in the future.

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.

Jellyfish Bioactive Compounds: Methods for Wet-Lab Work

PubMed Central

Frazão, Bárbara; Antunes, Agostinho

2016-01-01

The study of bioactive compounds from marine animals has provided, over time, an endless source of interesting molecules. Jellyfish are commonly targets of study due to their toxic proteins. However, there is a gap in reviewing successful wet-lab methods employed in these animals, which compromises the fast progress in the detection of related biomolecules. Here, we provide a compilation of the most effective wet-lab methodologies for jellyfish venom extraction prior to proteomic analysis—separation, identification and toxicity assays. This includes SDS-PAGE, 2DE, gel chromatography, HPLC, DEAE, LC-MS, MALDI, Western blot, hemolytic assay, antimicrobial assay and protease activity assay. For a more comprehensive approach, jellyfish toxicity studies should further consider transcriptome sequencing. We reviewed such methodologies and other genomic techniques used prior to the deep sequencing of transcripts, including RNA extraction, construction of cDNA libraries and RACE. Overall, we provide an overview of the most promising methods and their successful implementation for optimizing time and effort when studying jellyfish. PMID:27077869

Jellyfish Bioactive Compounds: Methods for Wet-Lab Work.

PubMed

Frazão, Bárbara; Antunes, Agostinho

2016-04-12

The study of bioactive compounds from marine animals has provided, over time, an endless source of interesting molecules. Jellyfish are commonly targets of study due to their toxic proteins. However, there is a gap in reviewing successful wet-lab methods employed in these animals, which compromises the fast progress in the detection of related biomolecules. Here, we provide a compilation of the most effective wet-lab methodologies for jellyfish venom extraction prior to proteomic analysis-separation, identification and toxicity assays. This includes SDS-PAGE, 2DE, gel chromatography, HPLC, DEAE, LC-MS, MALDI, Western blot, hemolytic assay, antimicrobial assay and protease activity assay. For a more comprehensive approach, jellyfish toxicity studies should further consider transcriptome sequencing. We reviewed such methodologies and other genomic techniques used prior to the deep sequencing of transcripts, including RNA extraction, construction of cDNA libraries and RACE. Overall, we provide an overview of the most promising methods and their successful implementation for optimizing time and effort when studying jellyfish.

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.

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.

On the dynamics of jellyfish locomotion via 3D particle tracking velocimetry

NASA Astrophysics Data System (ADS)

Piper, Matthew; Kim, Jin-Tae; Chamorro, Leonardo P.

2016-11-01

The dynamics of jellyfish (Aurelia aurita) locomotion is experimentally studied via 3D particle tracking velocimetry. 3D locations of the bell tip are tracked over 1.5 cycles to describe the jellyfish path. Multiple positions of the jellyfish bell margin are initially tracked in 2D from four independent planes and individually projected in 3D based on the jellyfish path and geometrical properties of the setup. A cubic spline interpolation and the exponentially weighted moving average are used to estimate derived quantities, including velocity and acceleration of the jellyfish locomotion. We will discuss distinctive features of the jellyfish 3D motion at various swimming phases, and will provide insight on the 3D contraction and relaxation in terms of the locomotion, the steadiness of the bell margin eccentricity, and local Reynolds number based on the instantaneous mean diameter of the bell.

Estimated harvesting on jellyfish in Sarawak

NASA Astrophysics Data System (ADS)

Bujang, Noriham; Hassan, Aimi Nuraida Ali

2017-04-01

There are three species of jellyfish recorded in Sarawak which are the Lobonema smithii (white jellyfish), Rhopilema esculenta (red jellyfish) and Mastigias papua. This study focused on two particular species which are L.smithii and R.esculenta. This study was done to estimate the highest carrying capacity and the population growth rate of both species by using logistic growth model. The maximum sustainable yield for the harvesting of this species was also determined. The unknown parameters in the logistic model were estimated using center finite different method. As for the results, it was found that the carrying capacity for L.smithii and R.esculenta were 4594.9246456819 tons and 5855.9894242086 tons respectively. Whereas, the population growth rate for both L.smithii and R.esculenta were estimated at 2.1800463754 and 1.144864086 respectively. Hence, the estimated maximum sustainable yield for harvesting for L.smithii and R.esculenta were 2504.2872047638 tons and 1676.0779949431 tons per year.

Pediatric jellyfish envenomation in the Mediterranean Sea.

PubMed

Glatstein, Miguel; Adir, Dikla; Galil, Bella; Scolnik, Dennis; Rimon, Ayelet; Pivko-Levy, Dikla; Hoyte, Christopher

2017-06-20

Several species of jellyfish native to the western Indian Ocean have entered the Mediterranean Sea through the Suez Canal. Since the late 1980s, each summer Rhopilema nomadica forms swarms as long as 100 km in the southeastern Levant and since the millennium aggregations of additional nonnative jellyfish have been sighted. The aim of this study was to evaluate children seen in the emergency department after jellyfish envenomations and to establish patterns of toxicity associated with this organism. A retrospective chart review was performed of all children presenting after jellyfish envenomations to the pediatric emergency department during the jellyfish swarming seasons (June-August) between 2010 and 2015. Extracted data included age, location of envenomation, pain scores, local and systemic manifestations, treatment provided in the emergency department and hospital, and disposition. Forty-one patients fulfilled the inclusion criteria; their ages ranged from 1 to 16 years and the median age was 9.4 years. Clinical manifestations were evident in all patients. Pain, present in 100% of patients, and an erythematous, whip-like, linear rash present in 87.8%, were the most common manifestations. The majority of 'burns' associated with jellyfish stings were first and second degree. The upper limb was affected in 34% and the lower limb was affected in 61% of cases. One patient suffered a sting to the abdomen and three patients suffered a sting to the face. Treatment in the emergency department included pain control, with nonsteroidal anti-inflammatory drugs and opiates, and antihistamines and topical corticosteroids in some cases. Nearly 49% of patients were seen during the summer of 2015 alone and seven patients in this group needed hospitalization. Reasons for hospitalization included systemic symptoms such as fever, chills, tachycardia, and muscle spasms. Two patients developed severe cellulitis, one patient had an anaphylactic reaction, and one was admitted to the

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.

Hypertonic saline in the treatment of corneal jellyfish stings.

PubMed

Yu Yao, Hsin; Cho, Ta Hsiung; Lu, Ching Hsiang; Lin, Feng Chi; Horng, Chi Ting

2016-02-01

A 20-year-old male soldier was hit by the jellyfish. The ophthalmic examination revealed that epithelial keratitis and corneal oedema in the right eye. We prescribed 3% NaCl eyedrops and 0.3% Norfloxacin eyedrops in the treatment of the corneal jellyfish stings. Two weeks later, the cornea in the right eye healed. In this case report, 3% NaCl eyedrops was effective in the treatment of acute phase of jellyfish stings of the cornea. © International Society of Travel Medicine, 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Jellyfish as vectors of bacterial disease for farmed salmon (Salmo salar).

PubMed

Ferguson, Hugh W; Delannoy, Christian M J; Hay, Stephen; Nicolson, James; Sutherland, David; Crumlish, Margaret

2010-05-01

Swarms or blooms of jellyfish are increasingly problematic and can result in high mortality rates of farmed fish. Small species of jellyfish, such as Phialella quadrata (13 mm in diameter), are capable of passing through the mesh of sea cages and being sucked into the mouth of fish during respiration. Results of the current study show that the initial damage to gills of farmed Atlantic salmon, likely produced by nematocyst-derived toxins from the jellyfish, was compounded by secondary bacterial infection with Tenacibaculum maritimum. Results also demonstrate that these filamentous bacteria were present on the mouth of the jellyfish and that their DNA sequences were almost identical to those of bacteria present on the salmon gills. This suggests that the bacterial lesions were not the result of an opportunistic infection of damaged tissue, as previously thought. Instead, P. quadrata is probably acting as a vector for this particular bacterial pathogen, and it is the first time that evidence to support such a link has been presented. No prior literature describing the presence of bacteria associated with jellyfish, except studies about their decay, could be found. It is not known if all jellyfish of this and other species carry similar bacteria or the relationship to each other. Their source, the role they play under other circumstances, and indeed whether the jellyfish were themselves diseased are also not known. The high proteolytic capabilities of T. maritimum mean that partially digested gill tissues were readily available to the jellyfish, which rely heavily on intracellular digestion for their nutrition.

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. Copyright © 2015 Elsevier Ltd. All rights reserved.

Observation of Moon Jellyfish Spatial Distribution Using a Scientific Echo Sounder and Underwater Camera

NASA Astrophysics Data System (ADS)

Mano, T.; Guo, X.; Fujii, N.; Yoshie, N.; Takeoka, H.

2016-02-01

Jellyfishes often form dense aggregation that causes a variety of social problems such as clogging seawater intake of power plant, breaking fisheries net and more. Understanding on jellyfish aggregation is not sufficient due to the difficulty of observation on this phenomenon. In this study, high-resolution observations using scientific echo sounder and underwater camera were carried out to reveal the fine structure of moon jellyfish distribution in a 3D space, as well as its abundance and temporal variation. In addition, water temperature, salinity and current speed were also measured for inferring formation mechanisms of jellyfish aggregation. The field observations with a target on moon jellyfish were carried out in August 2013 and August 2014, in a semi-enclosed bay in Japan. The ship equipped with scientific echo sounder was cruised over the entire bay to reveal the distribution and the form of the moon jellyfish aggregation. In August 2013, the jellyfish aggregations present a high density (maximum: 70 ind. /m3) and their outline shows spherical or zonal shape with a hollow structure. In August 2014, the jellyfish aggregations present a low density (maximum: 20 ind./m3) and the jellyfishes distributed in a layer structure over a wide area. The depth of jellyfish aggregation was consistent with thermocline. During three days of observations in 2014, the average population density of jellyfish reduced by one-tenth, showing a possibility that the jellyfish abundance in a bay may vary significantly in a short timescale of several days. Not only the active swimming of jellyfishes but also the ambient flow field associated with internal waves or Langmuir circulation may contribute to the jellyfish aggregations. In order to clarify the mechanisms for the formation of high density patchy aggregation, we plan to perform more detailed observations and numerical simulations that are able to capture the fine structure of these physical processes in the future.

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. Copyright © 2012 Elsevier B.V. All rights reserved.

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.

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. Copyright © 2013 Elsevier B.V. All rights reserved.

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.

Prediction, location, collection and transport of jellyfish (Cnidaria) and their polyps.

PubMed

Pierce, Justin

2009-03-01

With growing interest in research and display of living jellyfish workers are realizing the difficulty in obtaining and maintaining a healthy collection consistently. This report identifies the causes for the uncertainty in locating specimens and summarizes the latest technology, techniques and avenues for acquiring jellyfish for captive maintenance. Responsibility inherent with jellyfish transport for the prevention of incidental escape is also discussed.

Optimal hash arrangement of tentacles in jellyfish

NASA Astrophysics Data System (ADS)

Okabe, Takuya; Yoshimura, Jin

2016-06-01

At first glance, the trailing tentacles of a jellyfish appear to be randomly arranged. However, close examination of medusae has revealed that the arrangement and developmental order of the tentacles obey a mathematical rule. Here, we show that medusa jellyfish adopt the best strategy to achieve the most uniform distribution of a variable number of tentacles. The observed order of tentacles is a real-world example of an optimal hashing algorithm known as Fibonacci hashing in computer science.

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.

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

Ocular Jellyfish Stings: Report of 2 Cases and Literature Review.

PubMed

Mao, Chen; Hsu, Chien-Chin; Chen, Kuo-Tai

2016-09-01

An ocular jellyfish sting is an ophthalmic emergency and is rarely reported in the medical literature. With the evolution of aquatic activities and entertainment in recent decades, we anticipate that more patients with ocular jellyfish stings may be taken to the emergency department. However, most physicians are unaware of the typical presentations, suitable treatments, prognosis, and possible complications of ocular jellyfish stings. We reported 2 cases with ocular jellyfish stings and collected cases series from literature review. The most common clinical features of ocular jellyfish stings were pain, conjunctival injection, corneal lesion, and photophobia. All patients who sustained ocular stings did so during aquatic activities, and the best management at the scene was proper analgesics and copious irrigation of affected eyes with seawater or saline. The ocular lesions were treated with topical cycloplegics, topical steroids, topical antibiotics, topical antihistamines, and removal of nematocysts. The prognosis was good, and all patients recovered without any permanent sequelae. However, symptoms in some patients may last longer than 1 week. Reported complications included iritis, increased intraocular pressures, mydriasis, decreased accommodation, and peripheral anterior synechiae. Copyright © 2016 Wilderness Medical Society. Published by Elsevier Inc. All rights reserved.

Environmental forcing on jellyfish communities in a small temperate estuary.

PubMed

Primo, Ana Lígia; Marques, Sónia C; Falcão, Joana; Crespo, Daniel; Pardal, Miguel A; Azeiteiro, Ulisses M

2012-08-01

The impact of biological, hydrodynamic and large scale climatic variables on the jellyfish community of Mondego estuary was evaluated from 2003 to 2010. Plankton samples were collected at the downstream part of the estuary. Siphonophora Muggiaea atlantica and Diphyes spp. were the main jellyfish species. Jellyfish density was generally higher in summer and since 2005 densities had increased. Summer community analysis pointed out Acartia clausi, estuarine temperature and salinity as the main driven forces for the assemblage's structure. Also, Chl a, estuarine salinity, runoff and SST were identified as the major environmental factors influencing the siphonophores summer interannual variability. Temperature influenced directly and indirectly the community and fluctuation of jellyfish blooms in the Mondego estuary. This study represents a contribution to a better knowledge of the gelatinous plankton communities in small temperate estuaries. Copyright © 2012 Elsevier Ltd. All rights reserved.

Nutritional composition and total collagen content of three commercially important edible jellyfish.

PubMed

Khong, Nicholas M H; Yusoff, Fatimah Md; Jamilah, B; Basri, Mahiran; Maznah, I; Chan, Kim Wei; Nishikawa, Jun

2016-04-01

The study aimed to evaluate nutraceutical potential of three commercially significant edible jellyfish species (Acromitus hardenbergi, Rhopilema hispidum and Rhopilema esculentum). The bell and oral arms of these jellyfishes were analyzed for their proximate composition, calorific value, collagen content, amino acid profile, chemical score and elemental constituent. In general, all jellyfish possessed low calorific values (1.0-4.9 kcal/g D.W.) and negligible fat contents (0.4-1.8 g/100 g D.W.), while protein (20.0-53.9 g/100 g D.W.) and minerals (15.9-57.2g/100g D.W.) were found to be the richest components. Total collagen content of edible jellyfish varied from 122.64 to 693.92 mg/g D.W., accounting for approximately half its total protein content. The dominant amino acids in both bell and oral arms of all jellyfish studied includes glycine, glutamate, threonine, proline, aspartate and arginine, while the major elements were sodium, potassium, chlorine, magnesium, sulfur, zinc and silicon. Among the jellyfish, A. hardenbergi exhibited significantly higher total amino acids, chemical scores and collagen content (p<0.05) compared to R. hispidum and R. esculentum. Having good protein quality and low calories, edible jellyfish is an appealing source of nutritive ingredients for the development of oral formulations, nutricosmetics and functional food. Copyright © 2015 Elsevier Ltd. All rights reserved.

THE CASE OF A 14-YEAR-OLD BOY WHO EXPERIENCED ANAPHYLAXIS DUE TO JELLYFISH (MASTIGIAS PAPUA) INGESTION.

PubMed

Kubota, Shohei; Nozawa, Asako; Yanai, Takanori; Ozasa, Koji; Mori, Satomi; Kurihara, Kazuyuki

2017-01-01

We report a case of jellyfish allergy diagnosed via an oral food challenge. A 14-year-old boy had no history of jellyfish stings and had been eating commercially available jellyfish products twice yearly for the past 5-6 years. Five minutes after eating a commercially available boiled jellyfish product (100g), he experienced nausea, wheezing, and erythema and had visited our hospital. We suspected an anaphylactic reaction and treated him with intramuscular adrenaline injection, corticosteroid and antihistamine infusions, volume resuscitation, and salbutamol sulfate inhalation, which resulted in an improvement of the symptoms. One-month later in our hospital, we administered an oral food challenge of the same boiled jellyfish product bought at the same grocery store to the patient. After ingesting 14g of boiled jellyfish, he experienced erythema, wheezing, nausea, and abdominal pain. Several reports have described anaphylaxis caused by the ingestion of jellyfish, but the allergens in jellyfish have not been analyzed. A skin prick test for poly-gamma-glutamic acid (PGA) which is a component of jellyfish stings was negative. This suggests that he was sensitized to some allergen other than PGA via a route different from that of jellyfish sting. Our skin prick test for several kinds of edible jellyfish suggests that allergenicity may be different for different jellyfish.

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

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. Copyright © 2014 Elsevier Ltd. All rights reserved.

Kinematic decomposition and classification of octopus arm movements.

PubMed

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.

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

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. Copyright © 2015 Elsevier Ltd. All rights reserved.

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.

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.

Modeling Global Relationships Between Climate and Scyphozoan Jellyfish Blooms

NASA Astrophysics Data System (ADS)

Henschke, N.; Stock, C. A.; Sarmiento, J. L.

2016-02-01

Scyphozoan jellyfish have a complex lifecycle that involves alternation between a sexually reproducing medusa stage and a benthic, asexually reproducing polyp. Elevated jellyfish concentrations, or blooms, are a natural feature of healthy pelagic ecosystems, but it has been suggested that the frequency and magnitude of these blooms may increase globally as a result of anthropogenic changes such as overfishing, eutrophication and climate change. It has been difficult to substantiate this hypothesis, however, due to insufficient long-term datasets and limited life cycle data, particularly for the polyp stage. Polyp mortality is considered to be more important than medusa mortality for determining the biomass of the medusa population. We have developed a population model that incorporates both benthic and pelagic life history stages to better understand controls on jellyfish distributions their response to climate variability and change. The model tracks cohorts of both life stages with temperature and/or consumption driven relationships for growth, reproduction and mortality. The model was forced with a time-series of temperature and zooplankton biomass from three locations: Southampton Estuary, the Gulf of Mexico and the Black Sea and compared against co-located long-term ( 20 years) near monthly samples of jellyfish biomass. The model reproduces seasonal cycles and average medusa biomass at each location. Medusa biomass is positively correlated with increased temperature and food availability, and was more sensitive to changes in polyp mortality than medusa mortality - confirming the importance of the benthic polyp generation in regulating jellyfish bloom size. We are presently studying drivers of inter-annual variability at these sites before integration with global simulations.

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. Copyright © 2015 Elsevier Ltd. All rights reserved.

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

Jumbo Jellyfish or Massive Star?

NASA Image and Video Library

2010-06-17

Some might see a blood-red jellyfish, while others might see a pair of lips. In fact, the red-colored object in this new image from NASA Wide-field Infrared Survey Explorer is a sphere of stellar innards.

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.

Control of abusive water addition to Octopus vulgaris with non-destructive methods.

PubMed

Mendes, Rogério; Schimmer, Ove; Vieira, Helena; Pereira, João; Teixeira, Bárbara

2018-01-01

Abusive water addition to octopus has evidenced the need for quick non-destructive methods for product qualification in the industry and control of fresh commercial products in markets. Electric conductivity (EC)/pH and dielectric property measurements were selected to detect water uptake in octopus. A significant EC decrease was determined after soaking octopus in freshwater for 4 h. EC reflected the water uptake of octopus and the correspondent concentration decrease of available ions in the interstitial fluid. Significant correlations were determined between octopus water uptake, EC (R = -0.940) and moisture/protein (M/P) ratio (R = 0.923) changes. Seasonal and spatial variation in proximate composition did not introduce any uncertainty in EC discrimination of freshwater tampering. Immersion in 5 g L -1 sodium tripolyphosphate (STPP) increased EC to a value similar to control octopus. EC false negatives resulting from the use of additives (STPP and citric acid) were eliminated with the additional determination of pH. Octopus soaked in freshwater, STPP and citric acid can also be clearly discriminated from untreated samples (control) and also from frozen (thawed) ones using the dielectric properties. No significant differences in the dielectric property scores were found between octopus sizes or geographical locations. Simultaneous EC/pH or dielectric property measurements can be used in a handheld device for non-destructive water addition detection in octopus. M/P ratio can be used as a reference destructive method. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Protective Effect of Tetracycline against Dermal Toxicity Induced by Jellyfish Venom

PubMed Central

Kang, Changkeun; Jin, Yeung Bae; Kwak, Jeongsoo; Jung, Hongseok; Yoon, Won Duk; Yoon, Tae-Jin; Kim, Jong-Shu; Kim, Euikyung

2013-01-01

Background Previously, we have reported that most, if not all, of the Scyphozoan jellyfish venoms contain multiple components of metalloproteinases, which apparently linked to the venom toxicity. Further, it is also well known that there is a positive correlation between the inflammatory reaction of dermal tissues and their tissue metalloproteinase activity. Based on these, the use of metalloproteinase inhibitors appears to be a promising therapeutic alternative for the treatment of jellyfish envenomation. Methodology and Principal Findings Tetracycline (a metalloproteinase inhibitor) has been examined for its activity to reduce or prevent the dermal toxicity induced by Nemopilema nomurai (Scyphozoa: Rhizostomeae) jellyfish venom (NnV) using in vitro and in vivo models. HaCaT (human keratinocyte) and NIH3T3 (mouse fibroblast) incubated with NnV showed decreases in cell viability, which is associated with the inductions of metalloproteinase-2 and -9. This result suggests that the use of metalloproteinase inhibitors, such as tetracycline, may prevent the jellyfish venom-mediated local tissue damage. In vivo experiments showed that comparing with NnV-alone treatment, tetracycline pre-mixed NnV demonstrated a significantly reduced progression of dermal toxicity upon the inoculation onto rabbit skin. Conclusions/Significance It is believed that there has been no previous report on the therapeutic agent of synthetic chemical origin for the treatment of jellyfish venom-induced dermonecrosis based on understanding its mechanism of action except the use of antivenom treatment. Furthermore, the current study, for the first time, has proposed a novel mechanism-based therapeutic intervention for skin damages caused by jellyfish stings. PMID:23536767

LLL Octopus network: some lessons and future directions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Watson, R.W.

1978-06-27

The Octopus network, designed and developed by the Lawrence Livermore Laboratory, is a pioneering, high-performance, local computer network. Several lessons derived from the 14 years of experience in the evolution of Octopus are described, and some of the directions to be taken in its medium-term future are indicated. 3 figures.

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

Marine envenomations. Part 2--Other marine envenomations.

PubMed

Nimorakiotakis, B; Winkel, K D

2003-12-01

Australian waters contain a variety of venomous creatures, including jellyfish, stinging fish, blue-ringed octopus, sea snakes, cone snails and stingrays. Part 2 of this article focusses on common marine envenomations other than jellyfish stings. Even though mortality from these envenomations is low, there is a high level of morbidity especially with stonefish and other stinging fish envenomations. Some envenomations, however, are serious enough to require antivenom treatment and deaths still occasionally occur.

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. Copyright © 2014 Elsevier Ltd. All rights reserved.

Jellyfish (Cyanea nozakii) decomposition and its potential influence on marine environments studied via simulation experiments.

PubMed

Qu, Chang-Feng; Song, Jin-Ming; Li, Ning; Li, Xue-Gang; Yuan, Hua-Mao; Duan, Li-Qin; Ma, Qing-Xia

2015-08-15

A growing body of evidence suggests that the jellyfish population in Chinese seas is increasing, and decomposition of jellyfish strongly influences the marine ecosystem. This study investigated the change in water quality during Cyanea nozakii decomposition using simulation experiments. The results demonstrated that the amount of dissolved nutrients released by jellyfish was greater than the amount of particulate nutrients. NH4(+) was predominant in the dissolved matter, whereas the particulate matter was dominated by organic nitrogen and inorganic phosphorus. The high N/P ratios demonstrated that jellyfish decomposition may result in high nitrogen loads. The inorganic nutrients released by C. nozakii decomposition were important for primary production. Jellyfish decomposition caused decreases in the pH and oxygen consumption associated with acidification and hypoxia or anoxia; however, sediments partially mitigated the changes in the pH and oxygen. These results imply that jellyfish decomposition can result in potentially detrimental effects on marine environments. Copyright © 2015 Elsevier Ltd. All rights reserved.

Jellyfish Stings and Their Management: A Review

PubMed Central

Cegolon, Luca; Heymann, William C.; Lange, John H.; Mastrangelo, Giuseppe

2013-01-01

Jellyfish (cnidarians) have a worldwide distribution. Despite most being harmless, some species may cause local and also systemic reactions. Treatment of jellyfish envenomation is directed at: alleviating the local effects of venom, preventing further nematocyst discharges and controlling systemic reactions, including shock. In severe cases, the most important step is stabilizing and maintaining vital functions. With some differences between species, there seems to be evidence and consensus on oral/topical analgesics, hot water and ice packs as effective painkillers and on 30 s application of domestic vinegar (4%–6% acetic acid) to prevent further discharge of unfired nematocysts remaining on the skin. Conversely, alcohol, methylated spirits and fresh water should be carefully avoided, since they could massively discharge nematocysts; pressure immobilization bandaging should also be avoided, as laboratory studies show that it stimulates additional venom discharge from nematocysts. Most treatment approaches are presently founded on relatively weak evidence; therefore, further research (especially randomized clinical trials) is strongly recommended. Dissemination of appropriate treatment modalities should be deployed to better inform and educate those at risk. Adequate signage should be placed at beaches to notify tourists of the jellyfish risk. Swimmers in risky areas should wear protective equipment. PMID:23434796

Mediterranean Jellyfish Venoms: A Review on Scyphomedusae

PubMed Central

Mariottini, Gian Luigi; Pane, Luigi

2010-01-01

The production of natural toxins is an interesting aspect, which characterizes the physiology and the ecology of a number of marine species that use them for defence/offence purposes. Cnidarians are of particular concern from this point of view; their venoms are contained in specialized structures–the nematocysts–which, after mechanical or chemical stimulation, inject the venom in the prey or in the attacker. Cnidarian stinging is a serious health problem for humans in the zones where extremely venomous jellyfish or anemones are common, such as in temperate and tropical oceanic waters and particularly along several Pacific coasts, and severe cases of envenomation, including also lethal cases mainly induced by cubomedusae, were reported. On the contrary, in the Mediterranean region the problem of jellyfish stings is quite modest, even though they can have anyhow an impact on public health and be of importance from the ecological and economic point of view owing to the implications on ecosystems and on some human activities such as tourism, bathing and fishing. This paper reviews the knowledge about the various aspects related to the occurrence and the stinging of the Mediterranean scyphozoan jellyfish as well as the activity of their venoms. PMID:20479971

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. Copyright 2010 Elsevier Ltd. All rights reserved.

Comprehensive analysis of the origin of giant jellyfish near Qinhuangdao in summer

NASA Astrophysics Data System (ADS)

Wu, Lingjuan; Wu, Xiaofen; Bai, Tao

2017-09-01

A massive bloom of the giant jellyfish Nemopilema nomurai occurred in waters offQinhuangdao, a port city in Hebei Province, in July 2013. However, jellyfish larvae were not found in this location during the previous winter and spring. To determine the possible origin of the giant jellyfish medusa in the Bohai Sea, we developed a backward particle-tracking model and a series of numerical simulations were conducted by using the hydrodynamic, three-dimensional Regional Ocean Modeling System (ROMS) results. The simulated results showed that passive particles, representing jellyfish medusae, released in surface waters at different dates during the summer had consistent trajectories. Particles released at the sea surface on August 1 and 15 could be traced back to the center of the Bohai Sea and to waters between Feiyan Shoal and the new Huanghe (Yellow) River estuary. Particles released on July 1 and 15 could also be traced back to the center of the Bohai Sea and to waters between Feiyan Shoal and only to Zhuangxi tide station. However, none of the particles released in the middle and bottom water layers could be traced back to those areas. Based on the results of the numerical simulations, the distribution characteristics of seafloor sediments, and observational data for giant jellyfish in the region, we suggest that waters between Feiyan Shoal and the new Huanghe River estuary are the likely origin of giant jellyfish observed near Qinhuangdao in summer.

Hematological parameters on the effect of the jellyfish venom Cassiopea andromeda in animal models.

PubMed

Nabipour, Iraj; Mohebbi, Gholamhossein; Vatanpour, Hossein; Vazirizadeh, Amir

2017-04-01

For the first time, we previously recorded an enormous population of the Cassiopea andromeda jellyfish that had increased dramatically from Bushehr coasts of Iran. The sub-acute toxicity of the jellyfish venom in rat organs was correspondingly carried out. The data presented in this paper relate to the in vivo and in vitro hematological effects of this venomous species of jellyfish venom.

The elusive life cycle of scyphozoan jellyfish - metagenesis revisited

NASA Astrophysics Data System (ADS)

Ceh, Janja; Gonzalez, Jorge; Pacheco, Aldo S.; Riascos, José M.

2015-07-01

Massive proliferations of scyphozoan jellyfish considerably affect human industries and irreversibly change food webs. Efforts to understand the role of jellyfish in marine ecosystems are based on a life cycle model described 200 years ago. According to this paradigm the pelagic medusae is considered seasonal and alternates with the benthic polyp stage from which it derives. However, we provide evidence that a) the occurrence of several species of medusae is not restricted to a season in the year, they overwinter, b) polyp- and medusa generations are neither temporally nor spatially separated, and c) “metagenesis” which is defined as the alternation between sexual and asexual generations does not always occur. Hence we recommend additions to the current model and argue that the scyphozoan life cycle should be considered multi-modal, rather than metagenetic. The implications of these findings for jellyfish proliferations, including possible consequences and associated environmental drivers, are discussed.

The elusive life cycle of scyphozoan jellyfish--metagenesis revisited.

PubMed

Ceh, Janja; Gonzalez, Jorge; Pacheco, Aldo S; Riascos, José M

2015-07-08

Massive proliferations of scyphozoan jellyfish considerably affect human industries and irreversibly change food webs. Efforts to understand the role of jellyfish in marine ecosystems are based on a life cycle model described 200 years ago. According to this paradigm the pelagic medusae is considered seasonal and alternates with the benthic polyp stage from which it derives. However, we provide evidence that a) the occurrence of several species of medusae is not restricted to a season in the year, they overwinter, b) polyp- and medusa generations are neither temporally nor spatially separated, and c) "metagenesis" which is defined as the alternation between sexual and asexual generations does not always occur. Hence we recommend additions to the current model and argue that the scyphozoan life cycle should be considered multi-modal, rather than metagenetic. The implications of these findings for jellyfish proliferations, including possible consequences and associated environmental drivers, are discussed.

New design for interfacing computers to the Octopus network

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sloan, L.J.

1977-03-14

The Lawrence Livermore Laboratory has several large-scale computers which are connected to the Octopus network. Several difficulties arise in providing adequate resources along with reliable performance. To alleviate some of these problems a new method of bringing large computers into the Octopus environment is proposed.

[Skin cell response after jellyfish sting].

PubMed

Adamicová, Katarína; Výbohová, Desanka; Fetisovová, Želmíra; Nováková, Elena; Mellová, Yvetta

2016-01-01

Jellyfish burning is not commonly part of the professional finding in the central Europe health care laboratory. Holiday seaside tourism includes different and unusual presentations of diseases for our worklplaces. Sea water-sports and leisure is commonly connected with jellyfish burning and changes in the skin, that are not precisely described. Authors focused their research on detection of morphological and quantitative changes of some inflammatory cells in the skin biopsy of a 59-years-old woman ten days after a jellyfish stinging. Because of a comparison of findings the biopsy was performed in the skin with lesional and nonlesional skin. Both excisions of the skin were tested by imunohistochemical methods to detect CD68, CD163, CD30, CD4, CD3, CD8, CD20 a CD1a, to detect histiocytes, as well as several clones of lymphocytes and Langerhans cells (antigen presenting cells of skin), CD 117, toluidin blue and chloracetase esterase to detect mastocytes and neutrophils. Material was tested by immunofluorescent methods to detect IgA, IgM, IgG, C3, C4, albumin and fibrinogen. Representative view-fields were documented by microscope photocamera Leica DFC 420 C. Registered photos from both samples of the skin were processed by morphometrical analysis by the Vision Assistant software. A student t-test was used for statistical analysis of reached results. Mean values of individual found cells in the sample with lesion and without lesion were as follows: CD117 -2.64/0.37, CD68-6.86/1.63, CD163-3.13/2.23, CD30-1.36/0.02, CD4-3.51/0.32, CD8-8.22/0.50, CD3-10.69/0.66, CD20-0.56/0.66, CD1a-7.97/0.47 respectively. Generally mild elevation of eosinofils in lesional skin was detected. Increased values of tested cells seen in excision from lesional skin when compared with nonlesional ones were statistically significant in eight case at the level p = 0.033 to 0.001. A not statistically significant difference was found only in the group of CD163+ histiocytes. Authors detected numbers

Biomass of scyphozoan jellyfish, and its spatial association with 0-group fish in the Barents Sea.

PubMed

Eriksen, Elena; Prozorkevich, Dmitry; Trofimov, Aleksandr; Howell, Daniel

2012-01-01

An 0-group fish survey is conducted annually in the Barents Sea in order to estimate fish population abundance. Data on jellyfish by-catch have been recorded since 1980, although this dataset has never been analysed. In recent years, however, the ecological importance of jellyfish medusae has become widely recognized. In this paper the biomass of jellyfish (medusae) in 0-60 m depths is calculated for the period 1980-2010. During this period the climate changed from cold to warm, and changes in zooplankton and fish distribution and abundance were observed. This paper discusses the less well known ecosystem component; jellyfish medusae within the Phylum Cnidaria, and their spatial and temporal variation. The long term average was ca. 9×10⁸ kg, with some years showing biomasses in excess of 5×10⁹ kg. The biomasses were low during 1980s, increased during 1990s, and were highest in early 2000s with a subsequent decline. The bulk of the jellyfish were observed in the central parts of the Barents Sea, which is a core area for most 0-group fishes. Jellyfish were associated with haddock in the western area, with haddock and herring in the central and coastal area, and with capelin in the northern area of the Barents Sea. The jellyfish were present in the temperature interval 1°Cjellyfish occurring between 4.0-7.0°C. It seems that the ongoing warming trend may be favourable for Barents Sea jellyfish medusae; however their biomass has showed a recent moderate decline during years with record high temperatures in the Barents Sea. Jellyfish are undoubtedly an important component of the Barents Sea ecosystem, and the data presented here represent the best summary of jellyfish biomass and distribution yet published for the region.

Characterization of jellyfish turning using 3D-PTV

NASA Astrophysics Data System (ADS)

Xu, Nicole; Dabiri, John

2017-11-01

Aurelia aurita are oblate, radially symmetric jellyfish that consist of a gelatinous bell and subumbrellar muscle ring, which contracts to provide motive force. Swimming is typically modeled as a purely vertical motion; however, asymmetric activations of swim pacemakers (sensory organs that innervate the muscle at eight locations around the bell margin) result in turning and more complicated swim behaviors. More recent studies have examined flow fields around turning jellyfish, but the input/output relationship between locomotive controls and swim trajectories is unclear. To address this, bell kinematics for both straight swimming and turning are obtained using 3D particle tracking velocimetry (3D-PTV) by injecting biocompatible elastomer tags into the bell, illuminating the tank with ultraviolet light, and tracking the resulting fluorescent particles in a multi-camera setup. By understanding these kinematics in both natural and externally controlled free-swimming animals, we can connect neuromuscular control mechanisms to existing flow measurements of jellyfish turning for applications in designing more energy efficient biohybrid robots and underwater vehicles. NSF GRFP.

Hemolytic venoms from marine cnidarian jellyfish - an overview.

PubMed

Mariottini, Gian Luigi

2014-01-01

Cnidarian jellyfish are viewed as an emergent problem in several coastal zones throughout the world. Recurrent outbreaks pose a serious threat to tourists and bathers, as well as to sea-workers, involving health and economical aspects. As a rule, cnidarian stinging as a consequence of nematocyst firing induces merely local symptoms but cardiovascular or neurological complications can also occur. Hemolysis is a frequent effect of cnidarian stinging; this dangerous condition is known to be caused by several venoms and can sometimes be lethal. At present, the bulk of data concerning hemolytic cnidarian venoms comes from the study of benthic species, such as sea anemones and soft corals, but hemolytic factors were found in venoms of several siphonophore, cubozoan and scyphozoan jellyfish, which are mainly involved in the envenomation of bathers and sea-workers. Therefore, the aim of this paper is to review the scientific literature concerning the hemolytic venoms from cnidarian jellyfish taking into consideration their importance in human pathology as well as health implications and possible therapeutic measures.

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.

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. Copyright © 2012 Elsevier Ltd. All rights reserved.

Biogeography of jellyfish in the North Atlantic, by traditional and genomic methods

NASA Astrophysics Data System (ADS)

Licandro, P.; Blackett, M.; Fischer, A.; Hosia, A.; Kennedy, J.; Kirby, R. R.; Raab, K.; Stern, R.; Tranter, P.

2015-07-01

Scientific debate on whether or not the recent increase in reports of jellyfish outbreaks represents a true rise in their abundance has outlined a lack of reliable records of Cnidaria and Ctenophora. Here we describe different jellyfish data sets produced within the EU programme EURO-BASIN. These data were assembled with the aim of creating an improved baseline and providing new data that can be used to evaluate the current diversity and standing stocks of jellyfish in the North Atlantic region. Using a net adapted to sample gelatinous zooplankton quantitatively, cnidarians and ctenophores were collected from the epipelagic layer during spring-summer 2010-2013, in inshore and offshore waters between lat 59 and 68° N and long 62° W and 5° E. Jellyfish were also identified and counted in samples opportunistically collected by other sampling equipment in the same region and at two coastal stations in the Bay of Biscay and in the Gulf of Cadiz. Continuous Plankton Recorder (CPR) samples collected in 2009-2012 were re-analysed with the aim of identifying the time and location of cnidarian blooms across the North Atlantic Basin. Overall the data show high variability in jellyfish abundance and diversity, mainly in relation to different water masses and bathymetry. Higher densities were generally recorded on the shelves, where the communities tend to be more diverse due to the presence of meropelagic medusae. Comparison of net records from the G.O. Sars transatlantic cruise shows that information on jellyfish diversity differs significantly depending on the sampling gear utilised. Indeed, the big trawls mostly collect relatively large scyphozoan and hydrozoan species, while small hydrozoans and early stages of Ctenophora are only caught by smaller nets. Based on CPR data from 2009 to 2012, blooms of cnidarians occurred in all seasons across the whole North Atlantic Basin. Molecular analysis revealed that, contrary to previous hypotheses, the CPR is able to detect

Offshore marine constructions as propagators of moon jellyfish dispersal

NASA Astrophysics Data System (ADS)

Vodopivec, Martin; Peliz, Álvaro J.; Malej, Alenka

2017-08-01

We have studied the influence of offshore marine constructions on the moon jellyfish population in the Adriatic sea, where the newly set up substrates enable the formation of a new population based in the formerly unpopulated open waters. Our five-year long computer simulation uses a high resolution coupled bio-physical individual-based model to track the dispersal of the offspring from subpopulations originating from offshore and shore-based sources. According to our study, the platforms enhance connectivity between subpopulations of jellyfish polyps, help sustain existing shore-based subpopulations, contribute to jellyfish blooms in some areas, and play an important role in establishing connection with the rest of the Mediterranean, in addition to representing substantial amounts of available substrate. This is an aspect that is usually overlooked when evaluating the ecological impact of existing and future wind farms, oil and gas platforms, etc. Our approach could serve as a role model in future studies of ecological impacts of planned offshore constructions.

Ephyra jellyfish as a new model for ecotoxicological bioassays.

PubMed

Faimali, M; Garaventa, F; Piazza, V; Costa, E; Greco, G; Mazzola, V; Beltrandi, M; Bongiovanni, E; Lavorano, S; Gnone, G

2014-02-01

The aim of this study was a preliminary investigation on the possibility of using the ephyra of Scyphozoan jellyfish Aurelia aurita (Linnaeus, 1758), the common moon jellyfish, as an innovative model organism in marine ecotoxicology. A series of sequential experiments have been carried out in laboratory in order to investigate the influence of different culturing and methodological parameters (temperature, photoperiod, ephyrae density and age) on behavioural end-points (% of Frequency of Pulsations) and standardize a testing protocol. After that, the organisms have been exposed to two well known reference toxic compounds (Cadmium Nitrate and SDS) in order to analyse the acute and behavioural responses during static exposure. Results of this work indicate that the proposed behavioural end-point, frequency of pulsations (Fp), is an easily measurable one and can be used coupled with an acute one (immobilization) and that ephyrae of jellyfish are very promising model organisms for ecotoxicological investigation. Copyright © 2013 Elsevier Ltd. All rights reserved.

User's guide to the Octopus computer network (the SHOC manual)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schneider, C.; Thompson, D.; Whitten, G.

1975-06-02

This guide explains how to enter, run, and debug programs on the Octopus network. It briefly describes the network's operation, and directs the reader to other documents for further information. It stresses those service programs that will be most useful in the long run; ''quick'' methods that have little flexibility are not discussed. The Octopus timesharing network gives the user access to four CDC 7600 computers and a broad array of peripheral equipment, from any of 800 remote terminals. Octopus will soon include the Laboratory's STAR-100 computers. 9 figures, 5 tables. (auth)

Comparison of Diagnostic Accuracy between Octopus 900 and Goldmann Kinetic Visual Fields

PubMed Central

Rowe, Fiona J.; Rowlands, Alison

2014-01-01

Purpose. To determine diagnostic accuracy of kinetic visual field assessment by Octopus 900 perimetry compared with Goldmann perimetry. Methods. Prospective cross section evaluation of 40 control subjects with full visual fields and 50 patients with known visual field loss. Comparison of test duration and area measurement of isopters for Octopus 3, 5, and 10°/sec stimulus speeds. Comparison of test duration and type of visual field classification for Octopus versus Goldmann perimetry. Results were independently graded for presence/absence of field defect and for type and location of defect. Statistical evaluation comprised of ANOVA and paired t test for evaluation of parametric data with Bonferroni adjustment. Bland Altman and Kappa tests were used for measurement of agreement between data. Results. Octopus 5°/sec perimetry had comparable test duration to Goldmann perimetry. Octopus perimetry reliably detected type and location of visual field loss with visual fields matched to Goldmann results in 88.8% of results (K = 0.775). Conclusions. Kinetic perimetry requires individual tailoring to ensure accuracy. Octopus perimetry was reproducible for presence/absence of visual field defect. Our screening protocol when using Octopus perimetry is 5°/sec for determining boundaries of peripheral isopters and 3°/sec for blind spot mapping with further evaluation of area of field loss for defect depth and size. PMID:24587983

Jellyfish collagen matrices conserve the chondrogenic phenotype in two- and three-dimensional collagen matrices.

PubMed

Sewing, Judith; Klinger, Matthias; Notbohm, Holger

2017-03-01

Cartilage is a tissue with a very low capability of self-repair and the search for suitable materials supporting the chondrogenic phenotype and thus avoiding fibrotic dedifferentiation for matrix-associated chondrocyte transplantation (MACI) is ongoing. Jellyfish collagen was thought to be a suitable material mainly because of its good availability and easy handling. Collagen was extracted from jellyfish Rhopilema esculentum and the spreading of porcine chondrocytes on two (2D) and three dimensional (3D) collagen matrices examined in comparison with vertebrate collagens, placenta collagen and a commercially available matrix from porcine collagen type I (Optimaix®). In 2D, most chondrocytes kept their round shape on jellyfish collagen and vertebrate collagen type II compared with vertebrate collagen type I. This was also confirmed in 3D experiments, where chondrocytes preserved their phenotype on jellyfish collagen, as indicated by high collagen II/(II + I) ratios (≥54 % and ~92 % collagen type II in mRNA and protein, respectively) and no proliferation during 28 days of cultivation. These observations were discussed with a view to potential structural differences of jellyfish collagen, which might influence the integrin-mediated adhesion mechanisms of vertebrate cells on jellyfish collagen. This probably results from a lack of integrin-binding sites and the existence of an alternative binding mechanism such that cells kept their round shape on jellyfish collagen, preventing chondrocytes from dedifferentiation. Thus, collagen from R. esculentum is a very suitable and promising material for cartilage tissue engineering. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

Characterization and neutralization of Nemopilema nomurai (Scyphozoa: Rhizostomeae) jellyfish venom using polyclonal antibody.

PubMed

Kang, Changkeun; Han, Dae-Yong; Park, Kwang-Il; Pyo, Min-Jung; Heo, Yunwi; Lee, Hyunkyoung; Kim, Gon Sup; Kim, Euikyung

2014-08-01

Jellyfish stings have often caused serious health concerns for sea bathers especially in tropical waters. In the coastal areas of Korea, China and Japan, the blooming and stinging accidents of poisonous jellyfish species have recently increased, including Nemopilema nomurai. We have generated a polyclonal antibody against N. nomurai jellyfish venom (NnV) by the immunization of white rabbits with NnV antigen. In the present study, the antibody has been characterized for its neutralizing effect against NnV. At first, the presence of NnV polyclonal antibody has been confirmed from the immunized rabbit serum by Enzyme linked immunosorbent assay (ELISA). Then, the neutralizing activities of the polyclonal antibody have been investigated using cell-based toxicity test, hemolysis assay, and mice lethality test. When the polyclonal antibody was preincubated with NnV, it shows a high effectiveness in neutralizing the NnV toxicities in a concentration-dependent manner. Moreover, we explored proteomic analyses using 2-D SDS-PAGE and MALDI-TOF mass spectrometry to illustrate the molecular identities of the jellyfish venom. From this, 18 different protein families have been identified as jellyfish venom-derived proteins; the main findings of which are matrix metalloproteinase-14, astacin-like metalloprotease toxin 3 precursor. It is expected that the present results would have contributed to our understandings of the envenomation by N. nomurai, their treatment and some valuable knowledge on the pathological processes of the jellyfish stinging. Copyright © 2014 Elsevier Ltd. All rights reserved.

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

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.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Koutalos, Y.; Ebrey, T.G.; Tsuda, M.

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 bovinemore » 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.« less

Geographic patterns of fishes and jellyfish in Puget Sound surface waters

USGS Publications Warehouse

Rice, Casimir A.; Duda, Jeffrey J.; Greene, Correigh M.; Karr, James R.

2012-01-01

We explored patterns of small pelagic fish assemblages and biomass of gelatinous zooplankton (jellyfish) in surface waters across four oceanographic subbasins of greater Puget Sound. Our study is the first to collect data documenting biomass of small pelagic fishes and jellyfish throughout Puget Sound; sampling was conducted opportunistically as part of a juvenile salmon survey of daytime monthly surface trawls at 52 sites during May–August 2003. Biomass composition differed spatially and temporally, but spatial differences were more distinct. Fish dominated in the two northern basins of Puget Sound, whereas jellyfish dominated in the two southern basins. Absolute and relative abundance of jellyfish, hatchery Chinook salmon Oncorhynchus tshawytscha, and chum salmon O. keta decreased with increasing latitude, whereas the absolute and relative abundance of most fish species and the average fish species richness increased with latitude. The abiotic factors with the strongest relationship to biomass composition were latitude, water clarity, and sampling date. Further study is needed to understand the spatial and temporal heterogeneity in the taxonomic composition we observed in Puget Sound surface waters, especially as they relate to natural and anthropogenic influences.

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. Published by Elsevier Ireland Ltd.

Stings of edible jellyfish (Rhopilema hispidum, Rhopilema esculentum and Nemopilema nomurai) in Japanese waters.

PubMed

Kawahara, M; Uye, S; Burnett, J; Mianzan, H

2006-11-01

Three edible jellyfish Rhopilema hispidum, R. esculentum and Nemopilema nomurai are virulent to humans. We monitored one patient that was stung sequentially by these three species of jellyfish. The first species caused a persistent eruption, the second produced significant pruritus and the last induced only cutaneous symptoms rather than severe systemic disorders reported for its Chinese counterpart. The lesions of these jellyfish species are characteristic and common in workers harvesting medusae. There is no significant incidence of symptoms by ingesting these animals.

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.

Decomposition of jellyfish carrion in situ: Short-term impacts on infauna, benthic nutrient fluxes and sediment redox conditions.

PubMed

Chelsky, Ariella; Pitt, Kylie A; Ferguson, Angus J P; Bennett, William W; Teasdale, Peter R; Welsh, David T

2016-10-01

Jellyfish often form blooms that persist for weeks to months before they collapse en masse, resulting in the sudden release of large amounts of organic matter to the environment. This study investigated the biogeochemical and ecological effects of the decomposition of jellyfish in a shallow coastal lagoon in New South Wales, Australia. Catostylus mosaicus carrion was added to the surface of shallow sub-tidal sediments and biogeochemical parameters and macrofaunal abundance immediately below the jellyfish carrion were measured over three days. Sediment plots without jellyfish served as controls. Sediment oxygen demand and carbon and nitrogen efflux increased by up to 60-fold in the jellyfish plots, compared to control plots, and dissolved organic nutrient fluxes were more sustained than in previous studies due to the use of fresh rather than frozen biomass. The decomposing jellyfish progressively altered sediment redox conditions, indicated by an increase in porewater iron (II) and sulfide concentrations measured by high-resolution in situ diffusive samplers. Abundance of some macrofaunal taxa in the jellyfish plots decreased relative to controls, however, the abundance of a carnivorous gastropod, which was presumably feeding on the carrion, increased in the jellyfish plots. While jellyfish carrion may be a food source for some macrofauna, low oxygen conditions coupled with the accumulation of toxic dissolved sulfides in the near-surface sediments may explain the overall change in the macroinfaunal community. Copyright © 2016 Elsevier B.V. All rights reserved.

Learning from jellyfish: Fluid transport in muscular pumps at intermediate Reynolds numbers

NASA Astrophysics Data System (ADS)

Nawroth, Janna; Dabiri, John

2010-11-01

Biologically inspired hydrodynamic propulsion and maneuvering strategies promise the advancement of medical implants and minimally invasive clinical tools. We have chosen juvenile jellyfish as a model system for investigating fluid dynamics and morphological properties underlying fluid transport by a muscular pump at intermediate Reynolds numbers. Recently we have described how natural variations in viscous forces are balanced by changes in jellyfish body shape (phenotypic plasticity), to the effect of facilitating efficient body-fluid interaction. Complementing these studies in our live model organisms, we are also engaged in engineering an artificial jellyfish, that is, a jellyfish-inspired construct of a flexible plastic sheet actuated by a monolayer of rat cardiomyocytes. The main challenges here are (1) to derive a body shape and deformation suitable for effective fluid transport under physiological conditions, (2) to understand the mechanical properties of the muscular film and derive a design capable of the desired deformation, (3) to master the proper alignment and timely contraction of the muscle component needed to achieve the desired deformation, and (4) to evaluate the performance of the design.

Impact of stinging jellyfish proliferations along south Italian coasts: human health hazards, treatment and social costs.

PubMed

De Donno, Antonella; Idolo, Adele; Bagordo, Francesco; Grassi, Tiziana; Leomanni, Alessandro; Serio, Francesca; Guido, Marcello; Canitano, Mariarita; Zampardi, Serena; Boero, Ferdinando; Piraino, Stefano

2014-02-27

Stinging jellyfish outbreaks represent a health hazard, causing contact dermatitis and systemic reactions. This study investigated the epidemiology, severity, and treatment protocols of jellyfish stings in a coastal area with high tourist development and frequent stinging jellyfish outbreaks of the central Mediterranean (Salento, Southern Italy), and the associated costs for the Italian National Health Service. In 2007-2011, 1,733 bathers (mostly children and females) sought medical assistance following jellyfish stings, the main cause of human pathologies due to contact with marine organisms. The majority of events were reported in the years 2007-2009, whereas the occurrence of cnidarian jellyfish outbreaks has been increasingly reported in the same area since summer 2010. Most symptoms were limited to local and cutaneous reactions; conversely, 8.7% of cases evoked complications, mainly due to allergic reactions. The main drugs used were corticosteroids, locally applied and systemic (46% and 43%, respectively), and with ammonia (74%) as the main non-pharmacological treatment. The estimated cost of jellyfish-related first-aid services along the Salento coastline over the 5-year period was approximately 400,000 Euros. Therefore the management of jellyfish outbreak phenomena need coordinated research efforts towards a better understanding of underlying ecological mechanisms, together with the adoption of effective prevention policy, mitigation strategies, and appropriate planning of health services at tourist hot spots.

Environmental Control of Phase Transition and Polyp Survival of a Massive-Outbreaker Jellyfish

PubMed Central

Prieto, Laura; Astorga, Diana; Navarro, Gabriel; Ruiz, Javier

2010-01-01

A number of causes have been proposed to account for the occurrence of gelatinous zooplankton (both jellyfish and ctenophore) blooms. Jellyfish species have a complex life history involving a benthic asexual phase (polyp) and a pelagic sexual phase (medusa). Strong environmental control of jellyfish life cycles is suspected, but not fully understood. This study presents a comprehensive analysis on the physicochemical conditions that control the survival and phase transition of Cotylorhiza tuberculata; a scyphozoan that generates large outbreaks in the Mediterranean Sea. Laboratory experiments indicated that the influence of temperature on strobilation and polyp survival was the critical factor controlling the capacity of this species to proliferate. Early life stages were less sensitive to other factors such as salinity variations or the competitive advantage provided by zooxanthellae in a context of coastal eutrophication. Coherently with laboratory results, the presence/absence of outbreaks of this jellyfish in a particular year seems to be driven by temperature. This is the first time the environmental forcing of the mechanism driving the life cycle of a jellyfish has been disentangled via laboratory experimentation. Projecting this understanding to a field population under climatological variability results in a pattern coherent with in situ records. PMID:21072185

An analysis of dynamical factors influencing 2013 giant jellyfish bloom near Qinhuangdao in the Bohai Sea, China∗

NASA Astrophysics Data System (ADS)

Wu, Lingjuan; Wang, Jia; Gao, Song; Zheng, Xiangrong; Huang, Rui

2017-02-01

The explosive growth of Nemopilema nomurai occurred near the coastal waters of Qinhuangdao in July 2013. However, it did not take place in 2012. In this paper, the dynamical factors of wind, ocean current and sea temperature on giant jellyfish bloom in 2013 is analyzed by a comprehensive investigation. The numerical experiments are based on a numerical trajectory model of the jellyfish particles, which are released into the waters from Feiyan Shoal to New Yellow River Mouth, where is speculated as the most likely remote source of Qinhuangdao jellyfish bloom. The results show that in surface layer the jellyfish drift is jointly driven by the surface wind and surface current. For example, in northeastern Bohai Bay, the giant jellyfish moved northwestward in surface layer with influence of the westward wind and current anomalies during the second half of May in 2013, then approached the south of Jingtang Port by early June, and accumulated near Qinhuangdao in early July. The 2012 scenario during the same period was quite different. The jellyfish particles influencing waters near Qinhuangdao decreased with depth and there was few (no) particles influencing Qinhuangdao in middle (bottom) layer because the anticyclonic residual circulation weakened with depth in Bohai Bay. Besides, in the potential source waters of jellyfish, sea temperature in 2012 was more suitable for jellyfish bloom than that in 2013 if there was adequate bait. Hence, the specified direction of wind and current pattern in the Bohai Sea in surface layer (especially in the northeastern Bohai Bay during the second half of May) was more important for jellyfish bloom near Qinhuangdao than the sea temperature in the potential source.

Hemolytic venoms from marine cnidarian jellyfish – an overview

PubMed Central

Mariottini, Gian Luigi

2014-01-01

Cnidarian jellyfish are viewed as an emergent problem in several coastal zones throughout the world. Recurrent outbreaks pose a serious threat to tourists and bathers, as well as to sea-workers, involving health and economical aspects. As a rule, cnidarian stinging as a consequence of nematocyst firing induces merely local symptoms but cardiovascular or neurological complications can also occur. Hemolysis is a frequent effect of cnidarian stinging; this dangerous condition is known to be caused by several venoms and can sometimes be lethal. At present, the bulk of data concerning hemolytic cnidarian venoms comes from the study of benthic species, such as sea anemones and soft corals, but hemolytic factors were found in venoms of several siphonophore, cubozoan and scyphozoan jellyfish, which are mainly involved in the envenomation of bathers and sea-workers. Therefore, the aim of this paper is to review the scientific literature concerning the hemolytic venoms from cnidarian jellyfish taking into consideration their importance in human pathology as well as health implications and possible therapeutic measures. PMID:25386336

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. Copyright © 2011 Elsevier Ltd. All rights reserved.

High occurrence of jellyfish predation by black-browed and Campbell albatross identified by DNA metabarcoding.

PubMed

McInnes, Julie C; Alderman, Rachael; Lea, Mary-Anne; Raymond, Ben; Deagle, Bruce E; Phillips, Richard A; Stanworth, Andrew; Thompson, David R; Catry, Paulo; Weimerskirch, Henri; Suazo, Cristián G; Gras, Michaël; Jarman, Simon N

2017-09-01

Gelatinous zooplankton are a large component of the animal biomass in all marine environments, but are considered to be uncommon in the diet of most marine top predators. However, the diets of key predator groups like seabirds have conventionally been assessed from stomach content analyses, which cannot detect most gelatinous prey. As marine top predators are used to identify changes in the overall species composition of marine ecosystems, such biases in dietary assessment may impact our detection of important ecosystem regime shifts. We investigated albatross diet using DNA metabarcoding of scats to assess the prevalence of gelatinous zooplankton consumption by two albatross species, one of which is used as an indicator species for ecosystem monitoring. Black-browed and Campbell albatross scats were collected from eight breeding colonies covering the circumpolar range of these birds over two consecutive breeding seasons. Fish was the main dietary item at most sites; however, cnidarian DNA, primarily from scyphozoan jellyfish, was present in 42% of samples overall and up to 80% of samples at some sites. Jellyfish was detected during all breeding stages and consumed by adults and chicks. Trawl fishery catches of jellyfish near the Falkland Islands indicate a similar frequency of jellyfish occurrence in albatross diets in years of high and low jellyfish availability, suggesting jellyfish consumption may be selective rather than opportunistic. Warmer oceans and overfishing of finfish are predicted to favour jellyfish population increases, and we demonstrate here that dietary DNA metabarcoding enables measurements of the contribution of gelatinous zooplankton to the diet of marine predators. © 2017 John Wiley & Sons Ltd.

A numerical study of the benefits of driving jellyfish bells at their natural frequency.

PubMed

Hoover, Alexander; Miller, Laura

2015-06-07

A current question in swimming and flight is whether or not driving flexible appendages at their resonant frequency results in faster or more efficient locomotion. It has been suggested that jellyfish swim faster when the bell is driven at its resonant frequency. The goal of this study was to determine whether or not driving a jellyfish bell at its resonant frequency results in a significant increase in swimming velocity. To address this question, the immersed boundary method was used to solve the fully coupled fluid structure interaction problem of a flexible bell in a viscous fluid. Free vibration numerical experiments were used to determine the resonant frequency of the jellyfish bell. The jellyfish bells were then driven at frequencies ranging from above and below the resonant frequency. We found that jellyfish do swim fastest for a given amount of applied force when the bells are driven near their resonant frequency. Nonlinear effects were observed for larger deformations, shifting the optimal frequency to higher than the resonant frequency. We also found that the benefit of resonant forcing decreases for lower Reynolds numbers. Published by Elsevier Ltd.

Biogeography of jellyfish in the North Atlantic, by traditional and genomic methods

NASA Astrophysics Data System (ADS)

Licandro, P.; Blackett, M.; Fischer, A.; Hosia, A.; Kennedy, J.; Kirby, R. R.; Raab, K.; Stern, R.; Tranter, P.

2014-11-01

Scientific debate on whether the recent increase in reports of jellyfish outbreaks is related to a true rise in their abundance, have outlined the lack of reliable records of Cnidaria and Ctenophora. Here we describe different data sets produced within the EU program EUROBASIN, which have been assembled with the aim of presenting an up to date overview of the diversity and standing stocks of jellyfish in the North Atlantic region. Using a net adapted to sample gelatinous zooplankton quantitatively, Cnidaria and Ctenophora were collected in the epipelagic layer during spring-summer 2010-2013, in inshore and offshore waters between 59-68° N Lat and 62° W-5° E Long. Jellyfish were also identified and counted in samples opportunistically collected by other sampling equipment in the same region and at two coastal stations in the Bay of Biscay and in the Gulf of Cadiz. Continuous Plankton Recorder (CPR) samples collected in 2009-2012 were re-analysed with the aim of identifying the time and location of Cnidarian blooms across the North Atlantic basin. Overall the data show high variability in jellyfish abundance and diversity, mainly in relation with different water masses and with the bathymetry. Higher densities were generally recorded on the shelves, where populations tend to be more diversified due to the presence of meropelagic medusae. Comparisons of net records from the G.O. Sars transatlantic cruise show that information on jellyfish diversity differs significantly depending on the sampling gear utilised. Indeed, the big trawls mostly collect relatively large scyphozoan and hydrozoan species, while small hydrozoans and early stages of ctenophora are only caught by smaller nets. Based on CPR data from 2009-2012, blooms of Cnidarians occurred in all seasons across the whole North Atlantic basin. Molecular analysis revealed that, in contrast with what was previously hypothesized, the CPR is able to detect blooms of meroplanktonic and holoplanktonic hydrozoans and

The elusive life cycle of scyphozoan jellyfish – metagenesis revisited

PubMed Central

Ceh, Janja; Gonzalez, Jorge; Pacheco, Aldo S.; Riascos, José M.

2015-01-01

Massive proliferations of scyphozoan jellyfish considerably affect human industries and irreversibly change food webs. Efforts to understand the role of jellyfish in marine ecosystems are based on a life cycle model described 200 years ago. According to this paradigm the pelagic medusae is considered seasonal and alternates with the benthic polyp stage from which it derives. However, we provide evidence that a) the occurrence of several species of medusae is not restricted to a season in the year, they overwinter, b) polyp- and medusa generations are neither temporally nor spatially separated, and c) “metagenesis” which is defined as the alternation between sexual and asexual generations does not always occur. Hence we recommend additions to the current model and argue that the scyphozoan life cycle should be considered multi-modal, rather than metagenetic. The implications of these findings for jellyfish proliferations, including possible consequences and associated environmental drivers, are discussed. PMID:26153534

Fine-scale detection of pollutants by a benthic marine jellyfish.

PubMed

Epstein, Hannah E; Templeman, Michelle A; Kingsford, Michael J

2016-06-15

Local sources of pollution can vary immensely on small geographic scales and short time frames due to differences in runoff and adjacent land use. This study examined the rate of uptake and retention of trace metals in Cassiopea maremetens, a benthic marine jellyfish, over a short time frame and in the presence of multiple pollutants. This study also validated the ability of C. maremetens to uptake metals in the field. Experimental manipulation demonstrated that metal accumulation in jellyfish tissue began within 24h of exposure to treated water and trended for higher accumulation in the presence of multiple pollutants. C. maremetens was found to uptake trace metals in the field and provide unique signatures among locations. This fine-scale detection and rapid accumulation of metals in jellyfish tissue can have major implications for both biomonitoring and the trophic transfer of pollutants through local ecosystems. Copyright © 2016 Elsevier Ltd. All rights reserved.

Distribution of moon jellyfish Aurelia aurita in relation to summer hypoxia in Hiroshima Bay, Seto Inland Sea

NASA Astrophysics Data System (ADS)

Shoji, Jun; Kudoh, Takaya; Takatsuji, Hideyuki; Kawaguchi, Osamu; Kasai, Akihide

2010-02-01

Biological and physical surveys were conducted in order to investigate the relationship between environmental conditions and the distribution of moon jellyfish Aurelia aurita in Hiroshima Bay, western Seto Inland Sea, Japan. Moon jellyfish and ichthyoplankton were collected at 13 stations in Hiroshima Bay during monthly surveys from July to September in 2006 and 2007. Surface temperature in 2006 was significantly lower during the August and September cruises and surface salinity was lower during all cruises than in 2007. Moon jellyfish was the most dominant gelatinous plankton collected, accounting for 89.7% in wet weight. Mean moon jellyfish abundance in 2006 was higher than that in 2007 from July through September, with significant inter-year differences for July and September. Variability in precipitation and nutritional input from the Ohta River, northernmost part of Hiroshima Bay, were suggested as possible factors affecting the inter-annual variability in moon jellyfish abundance in the coastal areas of northern Hiroshima Bay. Moon jellyfish were more abundant in the coastal areas of northern Hiroshima Bay, where the dissolved oxygen (DO) concentration was lower, while low in the central part of the bay. Japanese anchovy Engraulis japonicus eggs were most dominant (58.1% in number) among the ichthyoplankton and were abundant in the central area of Hiroshima Bay. Explanatory analysis was conducted to detect possible effects of environmental conditions on the abundance of moon jellyfish and Japanese anchovy eggs during the summer months in Hiroshima Bay. Of the environmental conditions tested (temperature, salinity and DO of surface and bottom layers at each sampling station), bottom DO had the most significant effect on the moon jellyfish abundance: there was a negative correlation between the bottom DO and the moon jellyfish abundance in Hiroshima Bay during summer.

How to move with no rigid skeleton? The octopus has the answers.

PubMed

Yekutieli, Yoram; Sumbre, German; Flash, Tamar; Hochner, Binyamin

2002-12-01

The octopus is amazingly flexible and shows exceptional control and coordination in all its movements. It seems remarkable to us skeletal creatures that the octopus achieves all this without a single bone.

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.

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. © 2015 Wiley Periodicals, Inc.

Jellyfish extract induces apoptotic cell death through the p38 pathway and cell cycle arrest in chronic myelogenous leukemia K562 cells

PubMed Central

Kwak, Choong-Hwan; Abekura, Fukushi; Park, Jun-Young; Park, Nam Gyu; Chang, Young-Chae; Lee, Young-Choon; Chung, Tae-Wook; Ha, Ki-Tae; Son, Jong-Keun

2017-01-01

Jellyfish species are widely distributed in the world’s oceans, and their population is rapidly increasing. Jellyfish extracts have several biological functions, such as cytotoxic, anti-microbial, and antioxidant activities in cells and organisms. However, the anti-cancer effect of Jellyfish extract has not yet been examined. We used chronic myelogenous leukemia K562 cells to evaluate the mechanisms of anti-cancer activity of hexane extracts from Nomura’s jellyfish in vitro. In this study, jellyfish are subjected to hexane extraction, and the extract is shown to have an anticancer effect on chronic myelogenous leukemia K562 cells. Interestingly, the present results show that jellyfish hexane extract (Jellyfish-HE) induces apoptosis in a dose- and time-dependent manner. To identify the mechanism(s) underlying Jellyfish-HE-induced apoptosis in K562 cells, we examined the effects of Jellyfish-HE on activation of caspase and mitogen-activated protein kinases (MAPKs), which are responsible for cell cycle progression. Induction of apoptosis by Jellyfish-HE occurred through the activation of caspases-3,-8 and -9 and phosphorylation of p38. Jellyfish-HE-induced apoptosis was blocked by a caspase inhibitor, Z-VAD. Moreover, during apoptosis in K562 cells, p38 MAPK was inhibited by pretreatment with SB203580, an inhibitor of p38. SB203580 blocked jellyfish-HE-induced apoptosis. Additionally, Jellyfish-HE markedly arrests the cell cycle in the G0/G1 phase. Therefore, taken together, the results imply that the anti-cancer activity of Jellyfish-HE may be mediated apoptosis by induction of caspases and activation of MAPK, especially phosphorylation of p38, and cell cycle arrest at the Go/G1 phase in K562 cells. PMID:28133573

[Release and supplement of carbon, nitrogen and phosphorus from jellyfish (Nemopilema nomurai) decomposition in seawater].

PubMed

Qu, Chang-feng; Song, Jin-ming; Li, Ning; Li, Xue-gang; Yuan, Hua-mao; Duan, Li-qin

2016-01-01

Abstract: Jellyfish bloom has been increasing in Chinese seas and decomposition after jellyfish bloom has great influences on marine ecological environment. We conducted the incubation of Nemopilema nomurai decomposing to evaluate its effect on carbon, nitrogen and phosphorus recycling of water column by simulated experiments. The results showed that the processes of jellyfish decomposing represented a fast release of biogenic elements, and the release of carbon, nitrogen and phosphorus reached the maximum at the beginning of jellyfish decomposing. The release of biogenic elements from jellyfish decomposition was dominated by dissolved matter, which had a much higher level than particulate matter. The highest net release rates of dissolved organic carbon and particulate organic carbon reached (103.77 ± 12.60) and (1.52 ± 0.37) mg · kg⁻¹ · h⁻¹, respectively. The dissolved nitrogen was dominated by NH₄⁺-N during the whole incubation time, accounting for 69.6%-91.6% of total dissolved nitrogen, whereas the dissolved phosphorus was dominated by dissolved organic phosphorus during the initial stage of decomposition, being 63.9%-86.7% of total dissolved phosphorus and dominated by PO₄³⁻-P during the late stage of decomposition, being 50.4%-60.2%. On the contrary, the particulate nitrogen was mainly in particulate organic nitrogen, accounting for (88.6 ± 6.9) % of total particulate nitrogen, whereas the particulate phosphorus was mainly in particulate. inorganic phosphorus, accounting for (73.9 ±10.5) % of total particulate phosphorus. In addition, jellyfish decomposition decreased the C/N and increased the N/P of water column. These indicated that jellyfish decomposition could result in relative high carbon and nitrogen loads.

An analog VLSI chip emulating polarization vision of Octopus retina.

PubMed

Momeni, Massoud; Titus, Albert H

2006-01-01

Biological systems provide a wealth of information which form the basis for human-made artificial systems. In this work, the visual system of Octopus is investigated and its polarization sensitivity mimicked. While in actual Octopus retina, polarization vision is mainly based on the orthogonal arrangement of its photoreceptors, our implementation uses a birefringent micropolarizer made of YVO4 and mounted on a CMOS chip with neuromorphic circuitry to process linearly polarized light. Arranged in an 8 x 5 array with two photodiodes per pixel, each consuming typically 10 microW, this circuitry mimics both the functionality of individual Octopus retina cells by computing the state of polarization and the interconnection of these cells through a bias-controllable resistive network.

A Survey of Jellyfish Sting Knowledge among Naval Personnel in Northeast China.

PubMed

Kan, Ting; Gui, Li; Shi, Wenwen; Huang, Yan; Li, Shuang; Qiu, Chen

2016-07-19

Jellyfish envenomation is common along the coastal area, and can cause severe consequences. Naval personnel are among the high-risk population for this injury. The aim of this study was to assess knowledge regarding jellyfish envenomation among naval personnel in a navy unit in northeast China. A predesigned questionnaire was distributed to 120 naval members in January 2015. The data of 108 respondents were included in the statistical analysis. We found that 38.0% of the respondents selected jellyfish sting as the common wound in their units, and 13.0% had experienced or observed this injury. In addition, 63.0% of the participants rated their own knowledge as "low" or "none". The average score they got was 5.77 ± 2.50, with only 16.7% getting a score above 60% of the full score. The correct rates of five questions were below 60%. No statistical differences existed in the knowledge score among different groups of respondents defined by socio-demographic variables. Jellyfish sting is common in this navy unit, but personnel got a low score on the knowledge assessment. They also lacked confidence in first aid. Medical education and training should be implemented to address this issue.

Extract from the zooxanthellate jellyfish Cotylorhiza tuberculata modulates gap junction intercellular communication in human cell cultures.

PubMed

Leone, Antonella; Lecci, Raffaella Marina; Durante, Miriana; Piraino, Stefano

2013-05-22

On a global scale, jellyfish populations in coastal marine ecosystems exhibit increasing trends of abundance. High-density outbreaks may directly or indirectly affect human economical and recreational activities, as well as public health. As the interest in biology of marine jellyfish grows, a number of jellyfish metabolites with healthy potential, such as anticancer or antioxidant activities, is increasingly reported. In this study, the Mediterranean "fried egg jellyfish" Cotylorhiza tuberculata (Macri, 1778) has been targeted in the search forputative valuable bioactive compounds. A medusa extract was obtained, fractionated, characterized by HPLC, GC-MS and SDS-PAGE and assayed for its biological activity on breast cancer cells (MCF-7) and human epidermal keratinocytes (HEKa). The composition of the jellyfish extract included photosynthetic pigments, valuable ω-3 and ω-6 fatty acids, and polypeptides derived either from jellyfish tissues and their algal symbionts. Extract fractions showed antioxidant activity and the ability to affect cell viability and intercellular communication mediated by gap junctions (GJIC) differentially in MCF-7 and HEKa cells. A significantly higher cytotoxicity and GJIC enhancement in MCF-7 compared to HEKa cells was recorded. A putative action mechanism for the anticancer bioactivity through the modulation of GJIC has been hypothesized and its nutraceutical and pharmaceutical potential was discussed.

Resonance Raman spectroscopy of octopus rhodopsin and its photoproducts

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pande, C.; Pande, A.; Yue, K.T.

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 atmore » 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.« less

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.

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.

Rapid scavenging of jellyfish carcasses reveals the importance of gelatinous material to deep-sea food webs.

PubMed

Sweetman, Andrew K; Smith, Craig R; Dale, Trine; Jones, Daniel O B

2014-12-07

Jellyfish blooms are common in many oceans, and anthropogenic changes appear to have increased their magnitude in some regions. Although mass falls of jellyfish carcasses have been observed recently at the deep seafloor, the dense necrophage aggregations and rapid consumption rates typical for vertebrate carrion have not been documented. This has led to a paradigm of limited energy transfer to higher trophic levels at jelly falls relative to vertebrate organic falls. We show from baited camera deployments in the Norwegian deep sea that dense aggregations of deep-sea scavengers (more than 1000 animals at peak densities) can rapidly form at jellyfish baits and consume entire jellyfish carcasses in 2.5 h. We also show that scavenging rates on jellyfish are not significantly different from fish carrion of similar mass, and reveal that scavenging communities typical for the NE Atlantic bathyal zone, including the Atlantic hagfish, galatheid crabs, decapod shrimp and lyssianasid amphipods, consume both types of carcasses. These rapid jellyfish carrion consumption rates suggest that the contribution of gelatinous material to organic fluxes may be seriously underestimated in some regions, because jelly falls may disappear much more rapidly than previously thought. Our results also demonstrate that the energy contained in gelatinous carrion can be efficiently incorporated into large numbers of deep-sea scavengers and food webs, lessening the expected impacts (e.g. smothering of the seafloor) of enhanced jellyfish production on deep-sea ecosystems and pelagic-benthic coupling. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dupont, C.; Jongen, Y.; Arakawa, K.

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.more » 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.« less

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...

Jellyfish Stings Trigger Gill Disorders and Increased Mortality in Farmed Sparus aurata (Linnaeus, 1758) in the Mediterranean Sea.

PubMed

Bosch-Belmar, Mar; M'Rabet, Charaf; Dhaouadi, Raouf; Chalghaf, Mohamed; Daly Yahia, Mohamed Néjib; Fuentes, Verónica; Piraino, Stefano; Kéfi-Daly Yahia, Ons

2016-01-01

Jellyfish are of particular concern for marine finfish aquaculture. In recent years repeated mass mortality episodes of farmed fish were caused by blooms of gelatinous cnidarian stingers, as a consequence of a wide range of hemolytic, cytotoxic, and neurotoxic properties of associated cnidocytes venoms. The mauve stinger jellyfish Pelagia noctiluca (Scyphozoa) has been identified as direct causative agent for several documented fish mortality events both in Northern Europe and the Mediterranean Sea aquaculture farms. We investigated the effects of P. noctiluca envenomations on the gilthead sea bream Sparus aurata by in vivo laboratory assays. Fish were incubated for 8 hours with jellyfish at 3 different densities in 300 l experimental tanks. Gill disorders were assessed by histological analyses and histopathological scoring of samples collected at time intervals from 3 hours to 4 weeks after initial exposure. Fish gills showed different extent and severity of gill lesions according to jellyfish density and incubation time, and long after the removal of jellyfish from tanks. Jellyfish envenomation elicits local and systemic inflammation reactions, histopathology and gill cell toxicity, with severe impacts on fish health. Altogether, these results shows P. noctiluca swarms may represent a high risk for Mediterranean finfish aquaculture farms, generating significant gill damage after only a few hours of contact with farmed S. aurata. Due to the growth of the aquaculture sector and the increased frequency of jellyfish blooms in the coastal waters, negative interactions between stinging jellyfish and farmed fish are likely to increase with the potential for significant economic losses.

Jellyfish Stings Trigger Gill Disorders and Increased Mortality in Farmed Sparus aurata (Linnaeus, 1758) in the Mediterranean Sea

PubMed Central

Dhaouadi, Raouf; Chalghaf, Mohamed; Daly Yahia, Mohamed Néjib; Fuentes, Verónica; Piraino, Stefano; Kéfi-Daly Yahia, Ons

2016-01-01

Jellyfish are of particular concern for marine finfish aquaculture. In recent years repeated mass mortality episodes of farmed fish were caused by blooms of gelatinous cnidarian stingers, as a consequence of a wide range of hemolytic, cytotoxic, and neurotoxic properties of associated cnidocytes venoms. The mauve stinger jellyfish Pelagia noctiluca (Scyphozoa) has been identified as direct causative agent for several documented fish mortality events both in Northern Europe and the Mediterranean Sea aquaculture farms. We investigated the effects of P. noctiluca envenomations on the gilthead sea bream Sparus aurata by in vivo laboratory assays. Fish were incubated for 8 hours with jellyfish at 3 different densities in 300 l experimental tanks. Gill disorders were assessed by histological analyses and histopathological scoring of samples collected at time intervals from 3 hours to 4 weeks after initial exposure. Fish gills showed different extent and severity of gill lesions according to jellyfish density and incubation time, and long after the removal of jellyfish from tanks. Jellyfish envenomation elicits local and systemic inflammation reactions, histopathology and gill cell toxicity, with severe impacts on fish health. Altogether, these results shows P. noctiluca swarms may represent a high risk for Mediterranean finfish aquaculture farms, generating significant gill damage after only a few hours of contact with farmed S. aurata. Due to the growth of the aquaculture sector and the increased frequency of jellyfish blooms in the coastal waters, negative interactions between stinging jellyfish and farmed fish are likely to increase with the potential for significant economic losses. PMID:27100175

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

A Novel Approach to Primary Cell Culture for Octopus vulgaris Neurons

PubMed Central

Maselli, Valeria; Xu, Fenglian; Syed, Naweed I.; Polese, Gianluca; Di Cosmo, Anna

2018-01-01

Octopus vulgaris is a unique model system for studying complex behaviors in animals. It has a large and centralized nervous system made up of lobes that are involved in controlling various sophisticated behaviors. As such, it may be considered as a model organism for untangling the neuronal mechanisms underlying behaviors—including learning and memory. However, despite considerable efforts, Octopus lags behind its other counterparts vis-à-vis its utility in deciphering the cellular, molecular and synaptic mechanisms underlying various behaviors. This study represents a novel approach designed to establish a neuronal cell culture protocol that makes this species amenable to further exploitation as a model system. Here we developed a protocol that enables dissociation of neurons from two specific Octopus' brain regions, the vertical-superior frontal system and the optic lobes, which are involved in memory, learning, sensory integration and adult neurogenesis. In particular, cells dissociated with enzyme papain and cultured on Poly-D-Lysine-coated dishes with L15-medium and fetal bovine serum yielded high neuronal survival, axon growth, and re-growth after injury. This model was also explored to define optimal culture conditions and to demonstrate the regenerative capabilities of adult Octopus neurons after axotomy. This study thus further underscores the importance of Octopus neurons as a model system for deciphering fundamental molecular and cellular mechanism of complex brain function and underlying behaviors. PMID:29666582

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

Systems approach modelling of the interactive effects of fisheries, jellyfish and tourism in the Catalan coast

NASA Astrophysics Data System (ADS)

Tomlinson, Benjamin; Maynou, Francesc; Sabatés, Ana; Fuentes, Verónica; Canepa, Antonio; Sastre, Sergio

2018-02-01

Despite the large fluctuation in annual recordings of gelatinous plankton along the Catalan coast in the north western Mediterranean and the lack of long term data sets, there is a general perception that jellyfish abundances are increasing. Local authorities are concerned about the stranding events and arrivals of jellyfish to beaches and believe it could reduce the recreational appeal of the beaches - a valuable ecosystem service for the regional tourist industry. Previous studies also demonstrate the predation of jellyfish (Pelagia noctiluca ephyrae) upon some small pelagic fish larvae (Engraulis encrasicolus). Small pelagics are the principal source of revenue for the local fisheries. A social-ecological model was created in order to capture the effects of changes in abundance of P. noctiluca upon the local fisheries, the tourist industry and the wider economy. The following sub-models were constructed and connected following the systems approach framework methodology: an age-class based fisheries model; a jellyfish population matrix model; a jellyfish stranding model; a study on the impact of jellyfish strandings on beach users; and an economic input-output matrix. Various future scenarios for different abundances of jellyfish blooms were run. The "Expected blooms" scenario is similar to the quantity and size of blooms for 2000-2010. For a hypothetical "No blooms" scenario (standard background level of jellyfish but without any blooms) landings would increase by around 294 tonnes (5.1%) per year (averaged over 10 years) or approximately 0.19 M€ in profits per year (4.5%), and strandings would decrease by 49%. In a "Frequent blooms" scenario, landings would decrease by around 147 tonnes per year (2.5%) and decrease profits by 0.10 M€ per year (2.3%), and strandings would increase by 32%. Given the changes that these scenarios would cause on the regional gross domestic product and employment, this study concludes that the overall impact of either of these

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

Successful use of heat as first aid for tropical Australian jellyfish stings.

PubMed

Little, Mark; Fitzpatrick, Richard; Seymour, Jamie

2016-11-01

Currently the Australian Resuscitation Council (ARC) recommends dousing with vinegar followed by ice as first aid for jellyfish stings in tropical Australia, with limited evidence to support this recommendation (Li et al., 2013). We report our successful experience in using hot water immersion as first aid in treating two people stung by venomous tropical Australian jellyfish, one by Chironex fleckeri and one by Carukia barnesi. Copyright © 2016 Elsevier Ltd. All rights reserved.

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]. Copyright © 2014 Elsevier Ltd. All rights reserved.

Octopus senescence: the beginning of the end.

PubMed

Anderson, Roland C; Wood, James B; Byrne, Ruth A

2002-01-01

Senescence is a normal stage of an octopus's life cycle that often occurs before death. Some of the following symptoms typify it: lack of feeding, retraction of skin around the eyes, uncoordinated movement, increased undirected activity, and white unhealing lesions on the body. There is inter- and intraspecific variability. Senescence is not a disease or a result of disease, although diseases can also be a symptom of it. Both males and females go through a senescent stage before dying-the males after mating, the females while brooding eggs and after the eggs hatch. There are many aspects of octopus senescence that have not yet been studied. This study discusses the ecological implications of senescence.

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.

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.

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.

Jellyfish collagen scaffolds for cartilage tissue engineering.

PubMed

Hoyer, Birgit; Bernhardt, Anne; Lode, Anja; Heinemann, Sascha; Sewing, Judith; Klinger, Matthias; Notbohm, Holger; Gelinsky, Michael

2014-02-01

Porous scaffolds were engineered from refibrillized collagen of the jellyfish Rhopilema esculentum for potential application in cartilage regeneration. The influence of collagen concentration, salinity and temperature on fibril formation was evaluated by turbidity measurements and quantification of fibrillized collagen. The formation of collagen fibrils with a typical banding pattern was confirmed by atomic force microscopy and transmission electron microscopy analysis. Porous scaffolds from jellyfish collagen, refibrillized under optimized conditions, were fabricated by freeze-drying and subsequent chemical cross-linking. Scaffolds possessed an open porosity of 98.2%. The samples were stable under cyclic compression and displayed an elastic behavior. Cytotoxicity tests with human mesenchymal stem cells (hMSCs) did not reveal any cytotoxic effects of the material. Chondrogenic markers SOX9, collagen II and aggrecan were upregulated in direct cultures of hMSCs upon chondrogenic stimulation. The formation of typical extracellular matrix components was further confirmed by quantification of sulfated glycosaminoglycans. Copyright © 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Evaluating Energy Flows Through Jellyfish and Forage Fish and the Effects of Fishing on the Northern Humboldt Current Ecosystem

NASA Astrophysics Data System (ADS)

Chiaverano, L.; Robinson, K. L.; Ruzicka, J.; Quiñones, J.; Tam, J.; Acha, M.; Graham, W. M.; Brodeur, R.; Decker, M. B.; Hernandez, F., Jr.; Leaf, R.; Mianzan, H.; Uye, S. I.

2016-02-01

Increases in the frequency of jellyfish mass occurrences in a number of coastal areas around the globe have intensified concerns that some ecosystems are becoming "jellyfish-dominated". Gelatinous planktivores not only compete with forage fish for food, but also feed on fish eggs and larvae. When jellyfish abundance is high, the fraction of the energy and the efficiency at which it is transferred upwards in the food web are reduced compared with times when fish are dominant. Hence, ecosystems supporting major forage fish fisheries are the most likely to experience fish-to-jellyfish shifts due to the harvest pressure on mid-trophic planktivores. Although forage fish-jellyfish replacement cycles have been detected in recent decades in some productive, coastal ecosystems (e.g. Gulf of Mexico, Northern California Current), jellyfish are typically not included in ecosystem-based fisheries management (EBFM) production models. Here we explored the roles of jellyfish and forage fish as trophic energy transfer pathways to higher trophic levels in the Northern Humboldt Current (NHC) ecosystem, one of the most productive ecosystems in the world. A trophic network model with 33 functional groups was developed using ECOPATH and transformed to an end-to-end model using ECOTRAN techniques to map food web energy flows. Predicted, relative changes in functional group productivity were analyzed in simulations with varying forage fish consumption rates, jellyfish consumption rates, and forage fish harvest rates in a suite of static, alternative-energy-demand scenarios. Our modeling efforts will not only improve EBFM of forage fish and their predators in the NHC ecosystem, but also increase our understanding of trophic interactions between forage fish and large jellyfish, an important, but overlooked component in most ecosystem models to date.

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.

Concurrent jellyfish blooms and tenacibaculosis outbreaks in Northern Norwegian Atlantic salmon (Salmo salar) farms

PubMed Central

Brevik, Øyvind Jakobsen; Frisch, Kathleen; Watanabe, Kuninori; Duesund, Henrik; Nylund, Are

2017-01-01

Tenacibaculosis is an increasing problem in the Norwegian Atlantic salmon aquaculture industry causing significant economic losses. In September 2015, two separate outbreaks of suspected tenacibaculosis occurred at two Atlantic salmon farms in Finnmark County in Northern Norway. The events resulted in major losses of smolts newly transferred into seawater. Prior to, and during the outbreaks, large numbers of small jellyfish, identified as Dipleurosoma typicum (Boeck) were observed in the vicinity of the farms and inside the net-pens. This study investigates the possible link between the jellyfish, Tenacibaculum spp. and the tenacibaculosis outbreaks. Bacteriology, histology, scanning and transmission electron microscopy, and real-time RT-PCR screening were performed on both fish and jellyfish samples. Based on the findings, Tenacibaculum finnmarkense was found to be the dominant bacteria associated with the tenacibaculosis outbreaks at both sites and that D. typicum is unlikely to be a vector for this fish pathogenic bacterium. However, results do show that the jellyfish caused direct damage to the fish’s skin and may have exacerbated the bacterial infection by allowing an entry point for bacteria. PMID:29095885

Concurrent jellyfish blooms and tenacibaculosis outbreaks in Northern Norwegian Atlantic salmon (Salmo salar) farms.

PubMed

Småge, Sverre Bang; Brevik, Øyvind Jakobsen; Frisch, Kathleen; Watanabe, Kuninori; Duesund, Henrik; Nylund, Are

2017-01-01

Tenacibaculosis is an increasing problem in the Norwegian Atlantic salmon aquaculture industry causing significant economic losses. In September 2015, two separate outbreaks of suspected tenacibaculosis occurred at two Atlantic salmon farms in Finnmark County in Northern Norway. The events resulted in major losses of smolts newly transferred into seawater. Prior to, and during the outbreaks, large numbers of small jellyfish, identified as Dipleurosoma typicum (Boeck) were observed in the vicinity of the farms and inside the net-pens. This study investigates the possible link between the jellyfish, Tenacibaculum spp. and the tenacibaculosis outbreaks. Bacteriology, histology, scanning and transmission electron microscopy, and real-time RT-PCR screening were performed on both fish and jellyfish samples. Based on the findings, Tenacibaculum finnmarkense was found to be the dominant bacteria associated with the tenacibaculosis outbreaks at both sites and that D. typicum is unlikely to be a vector for this fish pathogenic bacterium. However, results do show that the jellyfish caused direct damage to the fish's skin and may have exacerbated the bacterial infection by allowing an entry point for bacteria.

Venom Proteome of the Box Jellyfish Chironex fleckeri

PubMed Central

Brinkman, Diane L.; Aziz, Ammar; Loukas, Alex; Potriquet, Jeremy; Seymour, Jamie; Mulvenna, Jason

2012-01-01

The nematocyst is a complex intracellular structure unique to Cnidaria. When triggered to discharge, the nematocyst explosively releases a long spiny, tubule that delivers an often highly venomous mixture of components. The box jellyfish, Chironex fleckeri, produces exceptionally potent and rapid-acting venom and its stings to humans cause severe localized and systemic effects that are potentially life-threatening. In an effort to identify toxins that could be responsible for the serious health effects caused by C. fleckeri and related species, we used a proteomic approach to profile the protein components of C. fleckeri venom. Collectively, 61 proteins were identified, including toxins and proteins important for nematocyte development and nematocyst formation (nematogenesis). The most abundant toxins identified were isoforms of a taxonomically restricted family of potent cnidarian proteins. These toxins are associated with cytolytic, nociceptive, inflammatory, dermonecrotic and lethal properties and expansion of this important protein family goes some way to explaining the destructive and potentially fatal effects of C. fleckeri venom. Venom proteins and their post-translational modifications (PTMs) were further characterized using toxin-specific antibodies and phosphoprotein/glycoprotein-specific stains. Results indicated that glycosylation is a common PTM of the toxin family while a lack of cross-reactivity by toxin-specific antibodies infers there is significant divergence in structure and possibly function among family members. This study provides insight into the depth and diversity of protein toxins produced by harmful box jellyfish and represents the first description of a cubozoan jellyfish venom proteome. PMID:23236347

Evaluating the role of large jellyfish and forage fishes as energy pathways, and their interplay with fisheries, in the Northern Humboldt Current System

NASA Astrophysics Data System (ADS)

Chiaverano, Luciano M.; Robinson, Kelly L.; Tam, Jorge; Ruzicka, James J.; Quiñones, Javier; Aleksa, Katrina T.; Hernandez, Frank J.; Brodeur, Richard D.; Leaf, Robert; Uye, Shin-ichi; Decker, Mary Beth; Acha, Marcelo; Mianzan, Hermes W.; Graham, William M.

2018-05-01

Large jellyfish are important consumers of plankton, fish eggs and fish larvae in heavily fished ecosystems worldwide; yet they are seldom included in fisheries production models. Here we developed a trophic network model with 41 functional groups using ECOPATH re-expressed in a donor-driven, end-to-end format to directly evaluate the efficiency of large jellyfish and forage fish at transferring energy to higher trophic levels, as well as the ecosystem-wide effects of varying jellyfish and forage fish consumption rates and fishing rates, in the Northern Humboldt Current system (NHCS) off of Peru. Large jellyfish were an energy-loss pathway for high trophic-level consumers, while forage fish channelized the production of lower trophic levels directly into production of top-level consumers. A simulated jellyfish bloom resulted in a decline in productivity of all functional groups, including forage fish (12%), with the exception of sea turtles. A modeled increase in forage fish consumption rate by 50% resulted in a decrease in large jellyfish productivity (29%). A simulated increase of 40% in forage fish harvest enhanced jellyfish productivity (24%), while closure of all fisheries caused a decline in large jellyfish productivity (26%) and productivity increases in upper level consumers. These outcomes not only suggest that jellyfish blooms and fisheries have important effects on the structure of the NHCS, but they also support the hypothesis that forage fishing provides a competitive release for large jellyfish. We recommend including jellyfish as a functional group in future ecosystem modeling efforts, including ecosystem-based approaches to fishery management of coastal ecosystems worldwide.

Analyzing Beach Recreationists' Preferences for the Reduction of Jellyfish Blooms: Economic Results from a Stated-Choice Experiment in Catalonia, Spain.

PubMed

Nunes, Paulo A L D; Loureiro, Maria L; Piñol, Laia; Sastre, Sergio; Voltaire, Louinord; Canepa, Antonio

2015-01-01

Jellyfish outbreaks and their consequences appear to be on the increase around the world, and are becoming particularly relevant in the Mediterranean. No previous studies have quantified tourism losses caused by jellyfish outbreaks. We used a stated-choice questionnaire and a Random Utility Model to estimate the amount of time respondents would be willing to add to their journey, in terms of reported extra travel time, in order to reduce the risk of encountering jellyfish blooms in the Catalan coast. The estimation results indicated that the respondents were willing to spend on average an additional 23.8% of their travel time to enjoy beach recreation in areas with a lower risk of jellyfish blooms. Using as a reference the opportunity cost of time, we found that the subsample of individuals who made a trade-off between the disutility generated by travelling longer in order to lower the risk of jellyfish blooms, and the utility gained from reducing this risk, are willing to pay on average €3.20 per beach visit. This estimate, combined with the respondents' mean income, yielded annual economic gains associated with reduction of jellyfish blooms on the Catalan coast around €422.57 million, or about 11.95% of the tourism expenditures in 2012. From a policy-making perspective, this study confirms the importance of the economic impacts of jellyfish blooms and the need for mitigation strategies. In particular, providing daily information using social media applications or other technical devices may reduce these social costs. The current lack of knowledge about jellyfish suggests that providing this information to beach recreationists may be a substantially effective policy instrument for minimising the impact of jellyfish blooms.

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

GASP. IX. Jellyfish galaxies in phase-space: an orbital study of intense ram-pressure stripping in clusters

NASA Astrophysics Data System (ADS)

Jaffé, Yara L.; Poggianti, Bianca M.; Moretti, Alessia; Gullieuszik, Marco; Smith, Rory; Vulcani, Benedetta; Fasano, Giovanni; Fritz, Jacopo; Tonnesen, Stephanie; Bettoni, Daniela; Hau, George; Biviano, Andrea; Bellhouse, Callum; McGee, Sean

2018-06-01

It is well known that galaxies falling into clusters can experience gas stripping due to ram pressure by the intra-cluster medium. The most spectacular examples are galaxies with extended tails of optically bright stripped material known as `jellyfish'. We use the first large homogeneous compilation of jellyfish galaxies in clusters from the WINGS and OmegaWINGS surveys, and follow-up MUSE observations from the GASP MUSE programme to investigate the orbital histories of jellyfish galaxies in clusters and reconstruct their stripping history through position versus velocity phase-space diagrams. We construct analytic models to define the regions in phase-space where ram-pressure stripping is at play. We then study the distribution of cluster galaxies in phase-space and find that jellyfish galaxies have on average higher peculiar velocities (and higher cluster velocity dispersion) than the overall population of cluster galaxies at all cluster-centric radii, which is indicative of recent infall into the cluster and radial orbits. In particular, the jellyfish galaxies with the longest gas tails reside very near the cluster cores (in projection) and are moving at very high speeds, which coincides with the conditions of the most intense ram pressure. We conclude that many of the jellyfish galaxies seen in clusters likely formed via fast (˜1-2 Gyr), incremental, outside-in ram-pressure stripping during first infall into the cluster in highly radial orbits.

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

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.

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.

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

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

Acute lion's mane jellyfish, Cyanea capillata (Cnideria: Scyphozoa), exposure to Atlantic salmon (Salmo salar L.).

PubMed

Powell, M D; Åtland, Å; Dale, T

2018-05-01

Jellyfish-induced gill pathology relies upon occasional diagnostic observations yet the extent and impact of jellyfish blooms on aquaculture may be significant. Idiopathic gill lesions are often observed in apparently healthy fish. This study exposed Atlantic salmon (Salmo salar L.) smolts to macerated Cyanea capillata at 2.5 and 5 g/L for 2 hr under controlled laboratory conditions. Blood chemistry and gill histopathology were examined over a subsequent 4-week period. Fish showed an acute response to the presence of jellyfish, including characteristic external "whiplash" discoloration of the skin and acute increases in blood electrolytes and CO 2 concentration; however, these were resolved within 4 days after exposure. Histopathologically, gills showed first an acute oedema with epithelial separation followed by focal haemorrhage and thrombus formation, and then progressive inflammatory epithelial hyperplasia that progressively resolved over the 4 weeks post-exposure. Results were consistent with the envenomation of gills with cytotoxic neurotoxins and haemolysins known to be produced by C. capillata. This study suggests that many focal hyperplastic lesions on gills, especially those involving focal thrombi, may be the result of jellyfish stings. Thus, the presence of jellyfish and their impact may be severe and understated in terms of marine fish aquaculture and fish welfare. © 2018 John Wiley & Sons Ltd.

Marine envenomations.

PubMed

Berling, Ingrid; Isbister, Geoffrey

2015-01-01

Marine stings are common but most are minor and do not require medical intervention. Severe and systemic marine envenoming is uncommon, but includes box jellyfish stings, Irukandji syndrome, major stingray trauma and blue-ringed octopus envenoming. Almost all marine injuries are caused by jellyfish stings, and penetrating injuries from spiny fish, stingrays or sea urchins. This article describes the presentation and management of marine envenomations and injuries that may occur in Australia. First aid for jellyfish includes tentacle removal, application of vinegar for box jellyfish, and hot water immersion (45°C for 20 min) for bluebottle jellyfish stings. Basic life support is essential for severe marine envenomings that result in cardiac collapse or paralysis. Irukandji syndrome causes severe generalised pain, autonomic excess and minimal local pain, which may require large amounts of analgesia, and, uncommonly, myocardial depression and pulmonary oedema occur. Penetrating marine injuries can cause significant trauma depending on location of the injury. Large and unclean wounds may have delayed healing and secondary infection if not adequately irrigated, debrided and observed.

Analyzing Beach Recreationists’ Preferences for the Reduction of Jellyfish Blooms: Economic Results from a Stated-Choice Experiment in Catalonia, Spain

PubMed Central

Nunes, Paulo A. L. D.; Loureiro, Maria L.; Piñol, Laia; Sastre, Sergio; Voltaire, Louinord; Canepa, Antonio

2015-01-01

Jellyfish outbreaks and their consequences appear to be on the increase around the world, and are becoming particularly relevant in the Mediterranean. No previous studies have quantified tourism losses caused by jellyfish outbreaks. We used a stated-choice questionnaire and a Random Utility Model to estimate the amount of time respondents would be willing to add to their journey, in terms of reported extra travel time, in order to reduce the risk of encountering jellyfish blooms in the Catalan coast. The estimation results indicated that the respondents were willing to spend on average an additional 23.8% of their travel time to enjoy beach recreation in areas with a lower risk of jellyfish blooms. Using as a reference the opportunity cost of time, we found that the subsample of individuals who made a trade-off between the disutility generated by travelling longer in order to lower the risk of jellyfish blooms, and the utility gained from reducing this risk, are willing to pay on average €3.20 per beach visit. This estimate, combined with the respondents’ mean income, yielded annual economic gains associated with reduction of jellyfish blooms on the Catalan coast around €422.57 million, or about 11.95% of the tourism expenditures in 2012. From a policy-making perspective, this study confirms the importance of the economic impacts of jellyfish blooms and the need for mitigation strategies. In particular, providing daily information using social media applications or other technical devices may reduce these social costs. The current lack of knowledge about jellyfish suggests that providing this information to beach recreationists may be a substantially effective policy instrument for minimising the impact of jellyfish blooms. PMID:26053674

Jellyfish as prey: frequency of predation and selective foraging of Boops boops (Vertebrata, Actinopterygii) on the mauve stinger Pelagia noctiluca (Cnidaria, Scyphozoa).

PubMed

Milisenda, Giacomo; Rosa, Sara; Fuentes, Veronica L; Boero, Ferdinando; Guglielmo, Letterio; Purcell, Jennifer E; Piraino, Stefano

2014-01-01

In recent years, jellyfish blooms have attracted considerable scientific interest for their potential impacts on human activities and ecosystem functioning, with much attention paid to jellyfish as predators and to gelatinous biomass as a carbon sink. Other than qualitative data and observations, few studies have quantified direct predation of fish on jellyfish to clarify whether they may represent a seasonally abundant food source. Here we estimate predation frequency by the commercially valuable Mediterranean bogue, Boops boops on the mauve stinger jellyfish, Pelagia noctiluca, in the Strait of Messina (NE Sicily). A total of 1054 jellyfish were sampled throughout one year to quantify predation by B. boops from bite marks on partially eaten jellyfish and energy density of the jellyfish. Predation by B. boops in summer was almost twice that in winter, and they selectively fed according to medusa gender and body part. Calorimetric analysis and biochemical composition showed that female jellyfish gonads had significantly higher energy content than male gonads due to more lipids and that gonads had six-fold higher energy content than the somatic tissues due to higher lipid and protein concentrations. Energetically, jellyfish gonads represent a highly rewarding food source, largely available to B. boops throughout spring and summer. During the remainder of the year, when gonads were not very evident, fish predation switched towards less-selective foraging on the somatic gelatinous biomass. P. noctiluca, the most abundant jellyfish species in the Mediterranean Sea and a key planktonic predator, may represent not only a nuisance for human leisure activities and a source of mortality for fish eggs and larvae, but also an important resource for fish species of commercial value, such as B. boops.

Jellyfish as Prey: Frequency of Predation and Selective Foraging of Boops boops (Vertebrata, Actinopterygii) on the Mauve Stinger Pelagia noctiluca (Cnidaria, Scyphozoa)

PubMed Central

Fuentes, Veronica L.; Boero, Ferdinando; Guglielmo, Letterio; Purcell, Jennifer E.; Piraino, Stefano

2014-01-01

In recent years, jellyfish blooms have attracted considerable scientific interest for their potential impacts on human activities and ecosystem functioning, with much attention paid to jellyfish as predators and to gelatinous biomass as a carbon sink. Other than qualitative data and observations, few studies have quantified direct predation of fish on jellyfish to clarify whether they may represent a seasonally abundant food source. Here we estimate predation frequency by the commercially valuable Mediterranean bogue, Boops boops on the mauve stinger jellyfish, Pelagia noctiluca, in the Strait of Messina (NE Sicily). A total of 1054 jellyfish were sampled throughout one year to quantify predation by B. boops from bite marks on partially eaten jellyfish and energy density of the jellyfish. Predation by B. boops in summer was almost twice that in winter, and they selectively fed according to medusa gender and body part. Calorimetric analysis and biochemical composition showed that female jellyfish gonads had significantly higher energy content than male gonads due to more lipids and that gonads had six-fold higher energy content than the somatic tissues due to higher lipid and protein concentrations. Energetically, jellyfish gonads represent a highly rewarding food source, largely available to B. boops throughout spring and summer. During the remainder of the year, when gonads were not very evident, fish predation switched towards less-selective foraging on the somatic gelatinous biomass. P. noctiluca, the most abundant jellyfish species in the Mediterranean Sea and a key planktonic predator, may represent not only a nuisance for human leisure activities and a source of mortality for fish eggs and larvae, but also an important resource for fish species of commercial value, such as B. boops. PMID:24727977

Extract from the Zooxanthellate Jellyfish Cotylorhiza tuberculata Modulates Gap Junction Intercellular Communication in Human Cell Cultures

PubMed Central

Leone, Antonella; Lecci, Raffaella Marina; Durante, Miriana; Piraino, Stefano

2013-01-01

On a global scale, jellyfish populations in coastal marine ecosystems exhibit increasing trends of abundance. High-density outbreaks may directly or indirectly affect human economical and recreational activities, as well as public health. As the interest in biology of marine jellyfish grows, a number of jellyfish metabolites with healthy potential, such as anticancer or antioxidant activities, is increasingly reported. In this study, the Mediterranean “fried egg jellyfish” Cotylorhiza tuberculata (Macri, 1778) has been targeted in the search forputative valuable bioactive compounds. A medusa extract was obtained, fractionated, characterized by HPLC, GC-MS and SDS-PAGE and assayed for its biological activity on breast cancer cells (MCF-7) and human epidermal keratinocytes (HEKa). The composition of the jellyfish extract included photosynthetic pigments, valuable ω-3 and ω-6 fatty acids, and polypeptides derived either from jellyfish tissues and their algal symbionts. Extract fractions showed antioxidant activity and the ability to affect cell viability and intercellular communication mediated by gap junctions (GJIC) differentially in MCF-7and HEKa cells. A significantly higher cytotoxicity and GJIC enhancement in MCF-7 compared to HEKa cells was recorded. A putative action mechanism for the anticancer bioactivity through the modulation of GJIC has been hypothesized and its nutraceutical and pharmaceutical potential was discussed. PMID:23697954

Effect of additives in the shelflife extension of chilled and frozen stored Indian octopus (Cistopus indicus).

PubMed

Manimaran, Uthaman; Shakila, Robinson Jeya; Shalini, Rajendran; Sivaraman, Balasubramanian; Sumathi, Ganesan; Selvaganapathi, Rajendran; Jeyasekaran, Geevarathnam

2016-02-01

In this study, the effect of commercial additives viz. cafodos and altesa employed to treat Indian octopus (Cistopus indicus) was examined during chilled and frozen storage. Shelf lives of treated and untreated octopus in ice were 6 and 8 days, respectively in ice. Treated and untreated frozen octopus had a shelf life of 40 days. Autolytic and microbiological changes were not controlled by the additives, as evidenced through rapid reduction in non-protein nitrogen (NPN) and α-amino nitrogen (α-AN) compounds; as well as accumulation of water soluble ammoniacal nitrogen and total volatile base- nitrogen (TVB-N) compounds. Loss of texture and colour were the major quality defects noticed in treated octopus as a result of enhanced protein solubility. Therefore, the additives approved for use in octopus neither enhanced the shelf life nor improved the sensory quality.

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

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.

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.

SI NMNH - Jellyfish Romance - Setting the Scene

Science.gov Websites

at least one species, Copula sivickisi (originally described as Carybdea sivickisi), has a more sivickisi medusae are probably not the animals that come to mind when one pictures a jellyfish. They are study were between four millimeters and ten millimeters across (smaller than a dime), and they can

Studying large jellyfish swimming hydrodynamics using a biomimetic robot named Cyro 2

NASA Astrophysics Data System (ADS)

Stewart, Colin; Krummel, Gregory; Villanueva, Alex; Marut, Kenneth; Priya, Shashank

2015-11-01

Some species of jellyfish can grow to great sizes, such as the lion's mane jellyfish (Cyanea capillata), which can span 2 m in diameter with tentacles 30 m long, roughly the same length as a blue whale. This is an impressive feat for an animal that begins its mobile life three orders of magnitude smaller. Such growth can require a large energy budget, suggesting that Cyanea may be a uniquely efficient swimmer, successful predator, or both. Either accolade would stem from a high level of hydrodynamic mastery as oblate jellyfish like Cyanea rely on the flow currents generated by bell pulsation for both propulsive thrust and prey encounter. However, further investigation has been hindered by the lack of reported quantitative flow measurements, perhaps due to the logistic challenges inherent to studying large specimen in vivo. Here, we used a 50 cm diameter biomimetic Cyanea robot named Cyro 2 as a proxy to study the hydrodynamics of large jellyfish. The effect of different trailing structure morphologies (e.g. oral arms and tentacles), swimming gaits, and kinematics on flow patterns were measured using PIV. Baseline swimming performance using biomimetic settings (but no trailing structures) was characterized by a cycle average velocity of 6.58 cm s-1, thrust of 1.9 N, and power input of 5.7 W, yielding a vehicle efficiency of 2.2% and a cost of transport of 15.4 J kg-1 m-1.

Spatiotemporal distribution of protozooplankton and copepod nauplii in relation to the occurrence of giant jellyfish in the Yellow Sea

NASA Astrophysics Data System (ADS)

Wang, Lu; Xu, Kuidong

2013-11-01

The occurrence of the giant jellyfish, Nemopilema nomurai, has been a frequent phenomenon in the Yellow Sea. However, the relationship between the giant jellyfish and protozoa, in particular ciliates, remains largely unknown. We investigated the distribution of nanoflagellates, ciliates, Noctiluca scintillans, and copepod nauplii along the transect 33°N in the Yellow Sea in June and August, 2012, during an occurrence of the giant jellyfish, and in October of that year when the jellyfish was absent. The organisms studied were mainly concentrated in the surface waters in summer, while in autumn they were evenly distributed in the water column. Nanoflagellate, ciliate, and copepod nauplii biomasses increased from early June to August along with jellyfish growth, the first two decreased in October, while N. scintillans biomass peaked in early June to 3 571 μg C/L and decreased in August and October. In summer, ciliate biomass greatly exceeded that of copepod nauplii (4.61-15.04 μg C/L vs. 0.34-0.89 μg C/L). Ciliate production was even more important than biomass, ranging from 6.59 to 34.19 μg C/(L·d) in summer. Our data suggest a tight and positive association among the nano-, micro-, and meso-zooplankton in the study area. Statistical analysis revealed that the abundance and total production of ciliate as well as loricate ciliate biomass were positively correlated with giant jellyfish biomass, indicating a possible predator-prey relationship between ciliates and giant jellyfish. This is in contrast to a previous study, which reported a significant reduction in ciliate standing crops due to the mass occurrence of N. nomurai in summer. Our study indicates that, with its high biomass and, in particular, high production ciliates might support the mass occurrence of giant jellyfish.

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.

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

Mode of action of the immunostimulatory effect of collagen from jellyfish.

PubMed

Nishimoto, Sogo; Goto, Yoko; Morishige, Hitoshi; Shiraishi, Ryusuke; Doi, Mikiharu; Akiyama, Koichi; Yamauchi, Satoshi; Sugahara, Takuya

2008-11-01

We have previously demonstrated that collagen from jellyfish simulated immunoglobulin and cytokine production by human-human hybridoma line HB4C5 cells and by human peripheral blood lymphocytes (hPBL). The mode of action of the collagen as an immunostimulatory factor was investigated. The expression levels of immunoglobulin mRNAs in HB4C5 cells, and those of tumor necrosis factor (TNF)-alpha, interferon (IFN)-gamma, and transforming growth factor (TGF)-beta in hPBL were up-regulated by jellyfish collagen. In addition, this collagen activated IgM production by transcription-suppressed HB4C5 cells that had been treated with actinomycin D. This collagen also enhanced IgM production by translation-suppressed HB4C5 cells that had been treated with sodium fluoride, but was ineffective in accelerating IgM production by HB4C5 cells treated with cycloheximide. Moreover, the intracellular IgM level in HB4C5 cells treated with the post-translation inhibitor, monensin, was increased by this collagen. These results suggest that collagen from jellyfish stimulated not only the transcription activity, but also the translation activity for enhanced immunoglobulin and cytokine production.

Occurrence of fatty acid chlorohydrins in jellyfish lipids.

PubMed

White, R H; Hager, L P

1977-11-01

Fatty acid chlorohydrins are characterized as lipid components of an edible jellyfish. The four isomers 9-chloro-10-hydroxypalmitic acid, 10-chloro-9-hydroxypalmitic acid, 9-chloro-10-hydroxystearic acid, and 10-chloro-9-hydroxystearic acid were identified by gas chromatography-mass spectrometry comparison of the methyl esters and their trimethylsilyl derivatives with known synthetic samples. Two additional isomers, 11-chloro-12-hydroxystearic acid and 12-chloro-11-hydroxystearic acid, were also found in the lipid by the identification of the expected mass spectral fragments of the trimethylsilyl (Me3Si) derivative of their methyl esters. These six isomeric compounds represented approximately 1.4% of the total extractable jellyfish lipid and were released from the lipid as methyl esters by boron trifluoride-methanol treatment. These isomers account for only about 30% of the organic chlorine in the lipid. Evidence is given that the remaining organic chlorine is also present as fatty acid chlorohydrins containing more than one hydroxyl group.

Surfactant-laden drop jellyfish-breakup mode induced by the Marangoni effect

NASA Astrophysics Data System (ADS)

Zhao, Hui; Zhang, Wen-Bin; Xu, Jian-Liang; Li, Wei-Feng; Liu, Hai-Feng

2017-03-01

Drop breakup is a familiar event in both nature and technology. In this study, we find that the bag breakup mode can be replaced by a new breakup mode: jellyfish breakup, when the surfactant concentration of a surfactant-laden drop is high. This new breakup mode has a morphology resembling a jellyfish with many long tentacles. This is due to the inhomogeneous distribution of surfactant in the process of drop deformation and breakup. The thin film of liquid can remain stable as a result of the Marangoni effect. Finally, we propose that the dimensionless surfactant concentration can serve as a criterion for breakup mechanisms.

Self-repairing symmetry in jellyfish through mechanically driven reorganization

PubMed Central

Abrams, Michael J.; Basinger, Ty; Yuan, William; Guo, Chin-Lin; Goentoro, Lea

2015-01-01

What happens when an animal is injured and loses important structures? Some animals simply heal the wound, whereas others are able to regenerate lost parts. In this study, we report a previously unidentified strategy of self-repair, where moon jellyfish respond to injuries by reorganizing existing parts, and rebuilding essential body symmetry, without regenerating what is lost. Specifically, in response to arm amputation, the young jellyfish of Aurelia aurita rearrange their remaining arms, recenter their manubria, and rebuild their muscular networks, all completed within 12 hours to 4 days. We call this process symmetrization. We find that symmetrization is not driven by external cues, cell proliferation, cell death, and proceeded even when foreign arms were grafted on. Instead, we find that forces generated by the muscular network are essential. Inhibiting pulsation using muscle relaxants completely, and reversibly, blocked symmetrization. Furthermore, we observed that decreasing pulse frequency using muscle relaxants slowed symmetrization, whereas increasing pulse frequency by lowering the magnesium concentration in seawater accelerated symmetrization. A mathematical model that describes the compressive forces from the muscle contraction, within the context of the elastic response from the mesoglea and the ephyra geometry, can recapitulate the recovery of global symmetry. Thus, self-repair in Aurelia proceeds through the reorganization of existing parts, and is driven by forces generated by its own propulsion machinery. We find evidence for symmetrization across species of jellyfish (Chrysaora pacifica, Mastigias sp., and Cotylorhiza tuberculata). PMID:26080418

Detection of microvasculature alterations by synchrotron radiation in murine with delayed jellyfish envenomation syndrome.

PubMed

Wang, Beilei; Zhang, Bo; Huo, Hua; Wang, Tao; Wang, Qianqian; Wu, Yuanlin; Xiao, Liang; Ren, Yuqi; Zhang, Liming

2014-04-01

Using the tentacle extract (TE) from the jellyfish Cyanea capillata, we have previously established a delayed jellyfish envenomation syndrome (DJES) model, which is meaningful for clinical interventions against jellyfish stings. However, the mechanism of DJES still remains unclear. Thus, this study aimed to explore its potential mechanism by detecting TE-induced microvasculature alterations in vivo and ex vivo. Using a third-generation synchrotron radiation facility, we, for the first time, directly observed the blood vessel alterations induced by jellyfish venom in vivo and ex vivo. Firstly, microvasculature imaging of whole-body mouse in vivo indicated that the small blood vessel branches in the liver and kidney in the TE-treated group, seemed much thinner than those in the control group. Secondly, 3D imaging of kidney ex vivo showed that the kidneys in the TE-treated group had incomplete vascular trees where distal vessel branches were partly missing and disorderly disturbed. Finally, histopathological analysis found that obvious morphological changes, especially hemorrhagic effects, were also present in the TE-treated kidney. Thus, TE-induced microvasculature changes might be one of the important mechanisms of multiple organ dysfunctions in DJES. In addition, the methods we employed here will probably facilitate further studies on developing effective intervention strategies against DJES. Copyright © 2014 Elsevier Ltd. All rights reserved.

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.

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

User's guide to the Octopus computer network (the SHOC manual)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schneider, C.; Thompson, D.; Whitten, G.

1977-07-18

This guide explains how to enter, run, and debug programs on the Octopus network. It briefly describes the network's operation, and directs the reader to other documents for further information. It stresses those service programs that will be most useful in the long run; ''quick'' methods that have little flexibility are not discussed. The Octopus timesharing network gives the user access to four CDC 7600 computers, two CDC STAR computers, and a broad array of peripheral equipment, from any of 800 or so remote terminals. 16 figures, 7 tables.

User's guide to the Octopus computer network (the SHOC manual)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schneider, C.; Thompson, D.; Whitten, G.

1976-10-07

This guide explains how to enter, run, and debug programs on the Octopus network. It briefly describes the network's operation, and directs the reader to other documents for further information. It stresses those service programs that will be most useful in the long run; ''quick'' methods that have little flexibility are not discussed. The Octopus timesharing network gives the user access to four CDC 7600 computers, two CDC STAR computers, and a broad array of peripheral equipment, from any of 800 or so remote terminals. 8 figures, 4 tables.

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.

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

..., Squid, and Octopus in the Gulf of Alaska AGENCY: National Marine Fisheries Service (NMFS), National... prohibiting directed fishing for sculpins, sharks, squid, and octopus in the Gulf of Alaska (GOA). This action..., and octopus in the GOA. DATES: Effective 1200 hrs, Alaska local time (A.l.t.), January 13, 2011...

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.

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.

Identification of allergens in the box jellyfish Chironex yamaguchii that cause sting dermatitis.

PubMed

Horiike, Takumi; Nagai, Hiroshi; Kitani, Seiichi

2015-01-01

Jellyfish stings cause painful, papular-urticarial eruptions due to the immediate allergic, acute toxic and persistent inflammatory responses. In spite of many marine accidents and their economic impact, modes of first-aid treatment remain conventional and specific allergen and medical treatment are not yet available. The purpose of this study was to define the specific allergen of the box jellyfish Chironex yamaguchii and to study the precise mechanism of the resulting dermatitis. We comprehensively studied the immunoglobulin-binding molecules from the box jellyfish C. yamaguchii with a purification procedure and Western blotting, using sera from 1 patient and from several controls. From the nematocyst wall and spine, we detected IgG-binding acidic glycoprotein (of 66 and 30 kDa) as determined by Western blot and ion-exchange chromatography. In addition, the 66-kDa protein was found to be an asparagine residue-coupled N-linked glycoprotein and the epitope resided in the protein fraction. We found that CqTX-A, the major toxic protein of the nematocyst, is also a heat-stable IgE-binding allergen. This was confirmed as a 45-kDa protein by Western blot from both nematocyst extracts and purified CqTX-A. The detection of these proteins may, in part, explain the combined immediate allergic-toxic and persistent allergic responses. Hopefully, our findings will lead to the development of specific venom immunotherapy for marine professional workers and tourists for jellyfish-sting dermatitis and anaphylaxis. © 2015 S. Karger AG, Basel.

76 FR 17360 - Fisheries of the Exclusive Economic Zone Off Alaska; Octopus in the Bering Sea and Aleutian...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-03-29

.... 101126521-0640-02] RIN 0648-XA322 Fisheries of the Exclusive Economic Zone Off Alaska; Octopus in the Bering... allowable catch of octopus in the Bering Sea and Aleutian Islands (BSAI). This action is necessary to allow... subpart H of 50 CFR part 600 and 50 CFR part 679. The 2011 initial total allowable catch (ITAC) of octopus...

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

... Octopus in the Bering Sea and Aleutian Islands Management Area AGENCY: National Marine Fisheries Service... catch of octopus by vessels using pot gear to fish for Pacific cod the BSAI. DATES: Effective 1200 hrs... and management measures prevent overfishing. The 2011 octopus overfishing level in the BSAI is 528...

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

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.

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.

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

Species-specific crab predation on the hydrozoan clinging jellyfish Gonionemus sp. (Cnidaria, Hydrozoa), subsequent crab mortality, and possible ecological consequences.

PubMed

Carman, Mary R; Grunden, David W; Govindarajan, Annette F

2017-01-01

Here we report a unique trophic interaction between the cryptogenic and sometimes highly toxic hydrozoan clinging jellyfish Gonionemus sp. and the spider crab Libinia dubia . We assessed species-specific predation on the Gonionemus medusae by crabs found in eelgrass meadows in Massachusetts, USA. The native spider crab species L. dubia consumed Gonionemus medusae, often enthusiastically, but the invasive green crab Carcinus maenus avoided consumption in all trials. One out of two blue crabs ( Callinectes sapidus ) also consumed Gonionemus , but this species was too rare in our study system to evaluate further. Libinia crabs could consume up to 30 jellyfish, which was the maximum jellyfish density treatment in our experiments, over a 24-hour period. Gonionemus consumption was associated with Libinia mortality. Spider crab mortality increased with Gonionemus consumption, and 100% of spider crabs tested died within 24 h of consuming jellyfish in our maximum jellyfish density containers. As the numbers of Gonionemus medusae used in our experiments likely underestimate the number of medusae that could be encountered by spider crabs over a 24-hour period in the field, we expect that Gonionemus may be having a negative effect on natural Libinia populations. Furthermore, given that Libinia overlaps in habitat and resource use with Carcinus , which avoids Gonionemus consumption, Carcinus populations could be indirectly benefiting from this unusual crab-jellyfish trophic relationship.

Species–specific crab predation on the hydrozoan clinging jellyfish Gonionemus sp. (Cnidaria, Hydrozoa), subsequent crab mortality, and possible ecological consequences

PubMed Central

Carman, Mary R.; Grunden, David W.

2017-01-01

Here we report a unique trophic interaction between the cryptogenic and sometimes highly toxic hydrozoan clinging jellyfish Gonionemus sp. and the spider crab Libinia dubia. We assessed species–specific predation on the Gonionemus medusae by crabs found in eelgrass meadows in Massachusetts, USA. The native spider crab species L. dubia consumed Gonionemus medusae, often enthusiastically, but the invasive green crab Carcinus maenus avoided consumption in all trials. One out of two blue crabs (Callinectes sapidus) also consumed Gonionemus, but this species was too rare in our study system to evaluate further. Libinia crabs could consume up to 30 jellyfish, which was the maximum jellyfish density treatment in our experiments, over a 24-hour period. Gonionemus consumption was associated with Libinia mortality. Spider crab mortality increased with Gonionemus consumption, and 100% of spider crabs tested died within 24 h of consuming jellyfish in our maximum jellyfish density containers. As the numbers of Gonionemus medusae used in our experiments likely underestimate the number of medusae that could be encountered by spider crabs over a 24-hour period in the field, we expect that Gonionemus may be having a negative effect on natural Libinia populations. Furthermore, given that Libinia overlaps in habitat and resource use with Carcinus, which avoids Gonionemus consumption, Carcinus populations could be indirectly benefiting from this unusual crab–jellyfish trophic relationship. PMID:29085761

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

.... 101126521-0640-02] RIN 0648-XA683 Fisheries of the Exclusive Economic Zone Off Alaska; Octopus in the Bering... 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 reached. DATES: Effective 1200 hrs, Alaska...

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.

Antioxidant activity of the giant jellyfish Nemopilema nomurai measured by the oxygen radical absorbance capacity and hydroxyl radical averting capacity methods.

PubMed

Harada, Kazuki; Maeda, Toshimichi; Hasegawa, Yoshiro; Tokunaga, Takushi; Ogawa, Shinya; Fukuda, Kyoko; Nagatsuka, Norie; Nagao, Keiko; Ueno, Shunshiro

2011-01-01

The giant jellyfish Nemopilema nomurai (reaching sizes of up to 2 m diameter and 150 kg), which forms dense blooms, has caused extensive damage to fisheries by overloading trawl nets, while its toxic nematocysts cause dermatological symptoms. Giant jellyfish are currently discarded on the grounds of pest control. However, the giant jellyfish is considered to be edible and is part of Chinese cuisine. Therefore, we investigated whether any benefits for human health may be derived from consumption of the jellyfish in order to formulate medicated diets. Antioxidant activity of Nemopilema nomurai was measured using the oxygen radical absorbance capacity (ORAC) and hydroxyl radical averting capacity (HORAC) methods. Based on the results, the ORAC value of the giant jellyfish freeze-dried sample was 541 µmol trolox equivalent (TE)/100 g and the HORAC value was 3,687 µmol gallic acid equivalent (GAE)/100 g. On the other hand, the IC50 value of hydroxyl radical scavenging activity measured by using the electron spin resonance method was 3.3%. In conclusion, the results suggest that the freeze-dried powder of the giant jellyfish Nemopilema nomurai is a potentially beneficial food for humans.

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

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

2017-05-01

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 (A 71 G 74 S 69 D 75 T 73 F 72 V 67 ) 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. Copyright © 2017 Elsevier Ltd. All rights reserved.

Jellyfish mucin may have potential disease-modifying effects on osteoarthritis

PubMed Central

2009-01-01

Background We aimed to study the effects of intra-articular injection of jellyfish mucin (qniumucin) on articular cartilage degeneration in a model of osteoarthritis (OA) created in rabbit knees by resection of the anterior cruciate ligament. Qniumucin was extracted from Aurelia aurita (moon jellyfish) and Stomolophus nomurai (Nomura's jellyfish) and purified by ion exchange chromatography. The OA model used 36 knees in 18 Japanese white rabbits. Purified qniumucin extracts from S. nomurai or A. aurita were used at 1 mg/ml. Rabbits were divided into four groups: a control (C) group injected with saline; a hyaluronic acid (HA)-only group (H group); two qniumucin-only groups (M groups); and two qniumucin + HA groups (MH groups). One milligram of each solution was injected intra-articularly once a week for 5 consecutive weeks, starting from 4 weeks after surgery. Ten weeks after surgery, the articular cartilage was evaluated macroscopically and histologically. Results In the C and M groups, macroscopic cartilage defects extended to the subchondral bone medially and laterally. When the H and both MH groups were compared, only minor cartilage degeneration was observed in groups treated with qniumucin in contrast to the group without qniumucin. Histologically, densely safranin-O-stained cartilage layers were observed in the H and two MH groups, but cartilage was strongly maintained in both MH groups. Conclusion At the concentrations of qniumucin used in this study, injection together with HA inhibited articular cartilage degeneration in this model of OA. PMID:19995451

Octopus microvasculature: permeability to ferritin and carbon.

PubMed

Browning, J

1979-01-01

The permeability of Octopus microvasculature was investigated by intravascular injection of carbon and ferritin. Vessels were tight to carbon while ferritin penetrated the pericyte junction, and was found extravascularly 1-2 min after its introduction. Vesicles occurred rarely in pericytes; fenestrae were absent. The discontinuous endothelial layer did not consitute a permeability barrier. The basement membrane, although retarding the movement of ferritin, was permeable to it; carbon did not penetrate the basement membrane. Evidence indicated that ferritin, and thus similarly sized and smaller water soluble materials, traverse the pericyte junction as a result of bulk fluid flow. Comparisons are made with the convective (or junctional) and slower, diffusive (or vesicular) passage of materials known to occur across the endothelium of continuous capillaries in mammals. Previous macrophysiological determinations concerning the permeability of Octopus vessels are questioned in view of these findings. Possible reasons for some major structural differences in the microcirculatory systems of cephalopods and vertebrates are briefly discussed.

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.

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

[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.

Toxic exposure to ethylene dibromide and mercuric chloride: effects on laboratory-reared octopuses.

PubMed

Adams, P M; Hanlon, R T; Forsythe, J W

1988-01-01

The effects of acute and chronic exposure to either ethylene dibromide (EDB) or mercuric chloride (MC) were studied in laboratory-reared Octopus joubini, O. maya and O. bimaculoides. The advantages of using octopuses were that the responses were immediate, highly visible and sensitive. All species demonstrated signs of toxicity to acute and chronic exposure to EDB and to MC. A dosage-sensitive relationship for the loss and subsequent recovery of locomotor response and of chromatophore expansion was found for each species after acute exposure. For each species the LC50 for chronic exposure occurred within 12 hr at 100 mg/l for EDB and within 3 hr at 1,000 mg/l for MC. This study demonstrated the potential usefulness of laboratory-reared octopuses in evaluating the toxicity of marine environmental pollutants.

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.

Jellyfish collagen stimulates production of TNF-α and IL-6 by J774.1 cells through activation of NF-κB and JNK via TLR4 signaling pathway.

PubMed

Putra, Agus Budiawan Naro; Nishi, Kosuke; Shiraishi, Ryusuke; Doi, Mikiharu; Sugahara, Takuya

2014-03-01

We previously reported that jellyfish collagen stimulates both the acquired and innate immune responses. In the acquired immune response, jellyfish collagen enhanced immunoglobulin production by lymphocytes in vitro and in vivo. Meanwhile, in the innate immune response jellyfish collagen promoted cytokine production and phagocytotic activity of macrophages. The facts that jellyfish collagen plays several potential roles in stimulating cytokine production by macrophages have further attracted us to uncover its mechanisms. We herein describe that the cytokine production-stimulating activity of jellyfish collagen was canceled by a Toll-like receptor 4 (TLR4) inhibitor. Moreover, jellyfish collagen stimulated phosphorylation of inhibitor of κBα (IκBα), promoted the translocation of nucleus factor-κB (NF-κB), and activated c-Jun N-terminal kinase (JNK). A JNK inhibitor also abrogated the cytokine production-stimulating activity of jellyfish collagen. These results suggest that jellyfish collagen may facilitate cytokine production by macrophages through activation of NF-κB and JNK via the TLR4 signaling pathways. Copyright © 2013 Elsevier Ltd. All rights reserved.

Concurrent environmental stressors and jellyfish stings impair caged European sea bass (Dicentrarchus labrax) physiological performances

PubMed Central

Bosch-Belmar, Mar; Giomi, Folco; Rinaldi, Alessandro; Mandich, Alberta; Fuentes, Verónica; Mirto, Simone; Sarà, Gianluca; Piraino, Stefano

2016-01-01

The increasing frequency of jellyfish outbreaks in coastal areas has led to multiple ecological and socio-economic issues, including mass mortalities of farmed fish. We investigated the sensitivity of the European sea bass (Dicentrarchus labrax), a widely cultured fish in the Mediterranean Sea, to the combined stressors of temperature, hypoxia and stings from the jellyfish Pelagia noctiluca, through measurement of oxygen consumption rates (MO2), critical oxygen levels (PO2crit), and histological analysis of tissue damage. Higher levels of MO2, PO2crit and gill damage in treated fish demonstrated that the synergy of environmental and biotic stressors dramatically impair farmed fish metabolic performances and increase their health vulnerability. As a corollary, in the current scenario of ocean warming, these findings suggest that the combined effects of recurrent hypoxic events and jellyfish blooms in coastal areas might also threaten wild fish populations. PMID:27301314

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

Exploring the Antibacterial and Antifungal Potential of Jellyfish-Associated Marine Fungi by Cultivation-Dependent Approaches.

PubMed

Yue, Yang; Yu, Huahua; Li, Rongfeng; Xing, Ronge; Liu, Song; Li, Pengcheng

2015-01-01

Fungi isolated from marine invertebrates are of considerable importance as new promising sources of unique secondary metabolites with significant biomedical potential. However, the cultivable fungal community harbored in jellyfish was less investigated. In this work, we seek to recover symbiotic fungi from different tissues of jellyfish Nemopilema nomurai. A total of seven morphotypes were isolated, which were assigned into four genera (Aspergillus, Cladosporium, Purpureocillium, and Tilletiopsis) from two phyla (Ascomycota and Basidiomycota) by comparing the rDNA-ITS sequences with the reference sequences in GenBank. The most fungi were found in the inner tissues of subumbrella. Two of the cultivation-independent procedures, changing media type and co-cultivation, were employed to maximize the complexity of metabolites. Thus, thirteen EtOAc gum were obtained and fingerprinted by High Performance Liquid Chromatography (HPLC) equipped with a photodiode array (PDA) detector. Antibacterial and antifungal activities of these complex mixtures were tested against a panel of bacterial and fungal pathogens. The antimicrobial results showed that all of the 13 EtOAc extracts displayed different levels of antibacterial activity, three of which exhibited strong to significant antibacterial activity to the bacterial pathogens Staphylococcus aureus and Salmonella entrica. Antifungal activity indicated that the EtOAc extracts from pure culture of Aspergillus versicolor and co-culture of A. versicolor and Tilletiopsis sp. in rice media were promising for searching new compounds, with the maximal mycelial growth inhibition of 82.32% ± 0.61% for Rhizoctonia solani and 48.41% ± 11.02% for Botrytis cinerea at 200 μg/ml, respectively. This study is the first report on the antibacterial and antifungal activity of jellyfish-associated fungi and allows the first sight into cultivable fungal community residing in jellyfish. Induced metabolites by cultivation-dependent approaches

Exploring the Antibacterial and Antifungal Potential of Jellyfish-Associated Marine Fungi by Cultivation-Dependent Approaches

PubMed Central

Yue, Yang; Yu, Huahua; Li, Rongfeng; Xing, Ronge; Liu, Song; Li, Pengcheng

2015-01-01

Fungi isolated from marine invertebrates are of considerable importance as new promising sources of unique secondary metabolites with significant biomedical potential. However, the cultivable fungal community harbored in jellyfish was less investigated. In this work, we seek to recover symbiotic fungi from different tissues of jellyfish Nemopilema nomurai. A total of seven morphotypes were isolated, which were assigned into four genera (Aspergillus, Cladosporium, Purpureocillium, and Tilletiopsis) from two phyla (Ascomycota and Basidiomycota) by comparing the rDNA-ITS sequences with the reference sequences in GenBank. The most fungi were found in the inner tissues of subumbrella. Two of the cultivation-independent procedures, changing media type and co-cultivation, were employed to maximize the complexity of metabolites. Thus, thirteen EtOAc gum were obtained and fingerprinted by High Performance Liquid Chromatography (HPLC) equipped with a photodiode array (PDA) detector. Antibacterial and antifungal activities of these complex mixtures were tested against a panel of bacterial and fungal pathogens. The antimicrobial results showed that all of the 13 EtOAc extracts displayed different levels of antibacterial activity, three of which exhibited strong to significant antibacterial activity to the bacterial pathogens Staphylococcus aureus and Salmonella entrica. Antifungal activity indicated that the EtOAc extracts from pure culture of Aspergillus versicolor and co-culture of A. versicolor and Tilletiopsis sp. in rice media were promising for searching new compounds, with the maximal mycelial growth inhibition of 82.32% ± 0.61% for Rhizoctonia solani and 48.41% ± 11.02% for Botrytis cinerea at 200 μg/ml, respectively. This study is the first report on the antibacterial and antifungal activity of jellyfish-associated fungi and allows the first sight into cultivable fungal community residing in jellyfish. Induced metabolites by cultivation-dependent approaches

Establishing and applying of a coupled individual based model of edible jellyfish(Rhopilema esculentum Kishinouye) releasing in the Liaodong Bay

NASA Astrophysics Data System (ADS)

Yin, Liping; Qiao, Fangli

2017-04-01

A three-dimensional circulation-surface wave coupled hydrodynamic model coupled with an individual-based jellyfish model was established to investigate the influence of physical process on edible jellyfish releasing stock enhancement in Liaodong Bay. Sensitivity experiments show that the wind intensity and direction have both direct and indirect impacts on the distribution of the jellyfish. When the wind is strong, the surface current in Liaodong Bay has the same direction of the wind. Under the co-effect of the ocean current transport and the surface wind transport, the jellyfish inhabits in the northeast of Liaodong bay, which is consistent with the observation. In the circumstance of weak wind, the circulation is clockwise and the jellyfish will spread around the 5m isobaths following the circulation. Research of the jellyfish distribution shows that the releasing jellyfish will stay in Liaodong bay in its whole life history, hence Liaodong Bay is a quite suitable area for enhancement releasing. The influence of the temperature on releasing region and date is also investigated. The threshold date during 2008 to 2016 is calculated, which is the date when the temperature of water within 10m isobaths in Liaodong Bay rises up to 15oC. In 2010, the threshold date came about one week later while the medusa releasing date remains the same in 2009. As a result, higher fatality rate of medusa caused by the cold water resulted in lower recapture rate in 2010. Therefore, the releasing date and location should be varied according to environmental conditions. The threshold date tends to appear earlier during 2008 to 2016, which suggests an earlier releasing date. In summer, due to the cold water mass intrusion from the south, the releasing date in the north area should be earlier than in the south.

Seasonal changes in infection with trematode species utilizing jellyfish as hosts: evidence of transmission to definitive host fish via medusivory

PubMed Central

Kondo, Yusuke; Ohtsuka, Susumu; Hirabayashi, Takeshi; Okada, Shoma; Ogawa, Nanako O.; Ohkouchi, Naohiko; Shimazu, Takeshi; Nishikawa, Jun

2016-01-01

In the Seto Inland Sea of western Japan, metacercariae of three species of trematodes, Lepotrema clavatum Ozaki, 1932, Cephalolepidapedon saba Yamaguti, 1970, and Opechona olssoni (Yamaguti, 1934), were found in the mesoglea of the jellyfish Aurelia aurita s.l., Chrysaora pacifica, and Cyanea nozakii. Moreover, these jellyfish frequently harbored juveniles of the fish species Psenopsis anomala, Thamnaconus modestus, and Trachurus japonicus. The former two fish species are well-known medusivores. We investigated seasonal changes in the prevalence and intensity of these metacercariae in their host jellyfish from March 2010 to September 2012 and presumed that infection by the trematodes of the definitive host fish occurs through these associations. The mean intensity of metacercariae in A. aurita s.l. clearly showed seasonality, being consistently high in June of each year. The intensity of metacercariae in C. nozakii was highest among all jellyfish hosts and appeared to be enhanced by medusivory of this second intermediate, and/or paratenic host. Trophic interactions between jellyfish and associated fish were verified using both gut content and stable isotope analyses. The detection of trematodes and nematocysts in the guts of P. anomala and T. modestus juveniles, in addition to stable isotope analysis, suggests that transmission of the parasites occurs via prey-predator relationships. In addition, the stable isotope analysis also suggested that P. anomala is more nutritionally dependent on jellyfish than Th. modestus and Tr. japonicus. PMID:27055563

Long-term fluctuations in circalunar Beach aggregations of the box jellyfish Alatina moseri in Hawaii, with links to environmental variability.

PubMed

Chiaverano, Luciano M; Holland, Brenden S; Crow, Gerald L; Blair, Landy; Yanagihara, Angel A

2013-01-01

The box jellyfish Alatina moseri forms monthly aggregations at Waikiki Beach 8-12 days after each full moon, posing a recurrent hazard to swimmers due to painful stings. We present an analysis of long-term (14 years: Jan 1998- Dec 2011) changes in box jellyfish abundance at Waikiki Beach. We tested the relationship of beach counts to climate and biogeochemical variables over time in the North Pacific Sub-tropical Gyre (NPSG). Generalized Additive Models (GAM), Change-Point Analysis (CPA), and General Regression Models (GRM) were used to characterize patterns in box jellyfish arrival at Waikiki Beach 8-12 days following 173 consecutive full moons. Variation in box jellyfish abundance lacked seasonality, but exhibited dramatic differences among months and among years, and followed an oscillating pattern with significant periods of increase (1998-2001; 2006-2011) and decrease (2001-2006). Of three climatic and 12 biogeochemical variables examined, box jellyfish showed a strong, positive relationship with primary production, >2 mm zooplankton biomass, and the North Pacific Gyre Oscillation (NPGO) index. It is clear that that the moon cycle plays a key role in synchronizing timing of the arrival of Alatina moseri medusae to shore. We propose that bottom-up processes, likely initiated by inter-annual regional climatic fluctuations influence primary production, secondary production, and ultimately regulate food availability, and are therefore important in controlling the inter-annual changes in box jellyfish abundance observed at Waikiki Beach.

Long-Term Fluctuations in Circalunar Beach Aggregations of the Box Jellyfish Alatina moseri in Hawaii, with Links to Environmental Variability

PubMed Central

Chiaverano, Luciano M.; Holland, Brenden S.; Crow, Gerald L.; Blair, Landy; Yanagihara, Angel A.

2013-01-01

The box jellyfish Alatina moseri forms monthly aggregations at Waikiki Beach 8–12 days after each full moon, posing a recurrent hazard to swimmers due to painful stings. We present an analysis of long-term (14 years: Jan 1998– Dec 2011) changes in box jellyfish abundance at Waikiki Beach. We tested the relationship of beach counts to climate and biogeochemical variables over time in the North Pacific Sub-tropical Gyre (NPSG). Generalized Additive Models (GAM), Change-Point Analysis (CPA), and General Regression Models (GRM) were used to characterize patterns in box jellyfish arrival at Waikiki Beach 8–12 days following 173 consecutive full moons. Variation in box jellyfish abundance lacked seasonality, but exhibited dramatic differences among months and among years, and followed an oscillating pattern with significant periods of increase (1998–2001; 2006–2011) and decrease (2001–2006). Of three climatic and 12 biogeochemical variables examined, box jellyfish showed a strong, positive relationship with primary production, >2 mm zooplankton biomass, and the North Pacific Gyre Oscillation (NPGO) index. It is clear that that the moon cycle plays a key role in synchronizing timing of the arrival of Alatina moseri medusae to shore. We propose that bottom-up processes, likely initiated by inter-annual regional climatic fluctuations influence primary production, secondary production, and ultimately regulate food availability, and are therefore important in controlling the inter-annual changes in box jellyfish abundance observed at Waikiki Beach. PMID:24194856

Seasonal changes in infection with trematode species utilizing jellyfish as hosts: evidence of transmission to definitive host fish via medusivory.

PubMed

Kondo, Yusuke; Ohtsuka, Susumu; Hirabayashi, Takeshi; Okada, Shoma; Ogawa, Nanako O; Ohkouchi, Naohiko; Shimazu, Takeshi; Nishikawa, Jun

2016-01-01

In the Seto Inland Sea of western Japan, metacercariae of three species of trematodes, Lepotrema clavatum Ozaki, 1932, Cephalolepidapedon saba Yamaguti, 1970, and Opechona olssoni (Yamaguti, 1934), were found in the mesoglea of the jellyfish Aurelia aurita s.l., Chrysaora pacifica, and Cyanea nozakii. Moreover, these jellyfish frequently harbored juveniles of the fish species Psenopsis anomala, Thamnaconus modestus, and Trachurus japonicus. The former two fish species are well-known medusivores. We investigated seasonal changes in the prevalence and intensity of these metacercariae in their host jellyfish from March 2010 to September 2012 and presumed that infection by the trematodes of the definitive host fish occurs through these associations. The mean intensity of metacercariae in A. aurita s.l. clearly showed seasonality, being consistently high in June of each year. The intensity of metacercariae in C. nozakii was highest among all jellyfish hosts and appeared to be enhanced by medusivory of this second intermediate, and/or paratenic host. Trophic interactions between jellyfish and associated fish were verified using both gut content and stable isotope analyses. The detection of trematodes and nematocysts in the guts of P. anomala and T. modestus juveniles, in addition to stable isotope analysis, suggests that transmission of the parasites occurs via prey-predator relationships. In addition, the stable isotope analysis also suggested that P. anomala is more nutritionally dependent on jellyfish than Th. modestus and Tr. japonicus. © Y. Kondo et al., published by EDP Sciences, 2016.

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.

The low diverse gastric microbiome of the jellyfish Cotylorhiza tuberculata is dominated by four novel taxa.

PubMed

Viver, Tomeu; Orellana, Luis H; Hatt, Janet K; Urdiain, Mercedes; Díaz, Sara; Richter, Michael; Antón, Josefa; Avian, Massimo; Amann, Rudolf; Konstantinidis, Konstantinos T; Rosselló-Móra, Ramon

2017-08-01

Cotylorhiza tuberculata is an important scyphozoan jellyfish producing population blooms in the Mediterranean probably due to pelagic ecosystem's decay. Its gastric cavity can serve as a simple model of microbial-animal digestive associations, yet poorly characterized. Using state-of-the-art metagenomic population binning and catalyzed reporter deposition fluorescence in situ hybridization (CARD-FISH), we show that only four novel clonal phylotypes were consistently associated with multiple jellyfish adults. Two affiliated close to Spiroplasma and Mycoplasma genera, one to chlamydial 'Candidatus Syngnamydia', and one to bacteroidetal Tenacibaculum, and were at least one order of magnitude more abundant than any other bacteria detected. Metabolic modelling predicted an aerobic heterotrophic lifestyle for the chlamydia, which were found intracellularly in Onychodromopsis-like ciliates. The Spiroplasma-like organism was predicted to be an anaerobic fermenter associated to some jellyfish cells, whereas the Tenacibaculum-like as free-living aerobic heterotroph, densely colonizing the mesogleal axis inside the gastric filaments. The association between the jellyfish and its reduced microbiome was close and temporally stable, and possibly related to food digestion and protection from pathogens. Based on the genomic and microscopic data, we propose three candidate taxa: 'Candidatus Syngnamydia medusae', 'Candidatus Medusoplasma mediterranei' and 'Candidatus Tenacibaculum medusae'. © 2017 Society for Applied Microbiology and John Wiley & Sons Ltd.

Symmetrization in jellyfish: reorganization to regain function, and not lost parts.

PubMed

Abrams, Michael J; Goentoro, Lea

2016-02-01

We recently reported a previously unidentified strategy of self-repair in the moon jellyfish Aurelia aurita. Rather than regenerating lost parts, juvenile Aurelia reorganize remaining parts to regain essential body symmetry. This process that we called symmetrization is rapid and frequent, and is not driven by cell proliferation or cell death. Instead, the swimming machinery generates mechanical forces that drive symmetrization. We found evidence for symmetrization across three other species of jellyfish (Chrysaora pacifica, Mastigias sp., and Cotylorhiza tuberculata). We propose reorganization to regain function without recovery of initial morphology as a potentially broad class of self-repair strategy beyond radially symmetrical animals, and discuss the implications of this finding on the evolution of self-repair strategies in animals. Copyright © 2015 The Authors. Published by Elsevier GmbH.. All rights reserved.

Direct evidence of an efficient energy transfer pathway from jellyfish carcasses to a commercially important deep-water species.

PubMed

Dunlop, Kathy M; Jones, Daniel O B; Sweetman, Andrew K

2017-12-12

Here we provide empirical evidence of the presence of an energetic pathway between jellyfish and a commercially important invertebrate species. Evidence of scavenging on jellyfish carcasses by the Norway lobster (Nephrops norvegicus) was captured during two deployments of an underwater camera system to 250-287 m depth in Sognefjorden, western Norway. The camera system was baited with two Periphylla periphylla (Scyphozoa) carcasses to simulate the transport of jellyfish detritus to the seafloor, hereby known as jelly-falls. N. norveigus rapidly located and consumed a large proportion (>50%) of the bait. We estimate that the energy input from jelly-falls may represent a significant contribution to N. norvegicus energy demand (0.21 to 10.7 times the energy required for the population of N. norvegicus in Sognefjorden). This potentially high energetic contribution from jelly-falls highlights a possible role of gelatinous material in the support of commercial fisheries. Such an energetic pathway between jelly-falls and N. norvegicus could become more important with increases in jellyfish blooms in some regions.

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. © 2015 Wiley Periodicals, Inc.

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. © 2015. Published by The Company of Biologists Ltd.

Protective effects of batimastat against hemorrhagic injuries in delayed jellyfish envenomation syndrome models.

PubMed

Wang, Beilei; Liu, Dan; Liu, Guoyan; Zhang, Xin; Wang, Qianqian; Zheng, Jiemin; Zhou, Yonghong; He, Qian; Zhang, Liming

2015-12-15

Previously, we established delayed jellyfish envenomation syndrome (DJES) models and proposed that the hemorrhagic toxins in jellyfish tentacle extracts (TE) play a significant role in the liver and kidney injuries of the experimental model. Further, we also demonstrated that metalloproteinases are the central toxic components of the jellyfish Cyanea capillata (C. capillata), which may be responsible for the hemorrhagic effects. Thus, metalloproteinase inhibitors appear to be a promising therapeutic alternative for the treatment of hemorrhagic injuries in DJES. In this study, we examined the metalloproteinase activity of TE from the jellyfish C. capillata using zymography analyses. Our results confirmed that TE possessed a metalloproteinase activity, which was also sensitive to heat. Then, we tested the effect of metalloproteinase inhibitor batimastat (BB-94) on TE-induced hemorrhagic injuries in DJES models. Firstly, using SR-based X-ray microangiography, we found that BB-94 significantly improved TE-induced hepatic and renal microvasculature alterations in DJES mouse model. Secondly, under synchrotron radiation micro-computed tomography (SR-μCT), we also confirmed that BB-94 reduced TE-induced hepatic and renal microvasculature changes in DJES rat model. In addition, being consistent with the imaging results, histopathological and terminal deoxynucleotidyl transferase-mediated UTP end labeling (TUNEL)-like staining observations also clearly corroborated this hypothesis, as BB-94 was highly effective in neutralizing TE-induced extensive hemorrhage and necrosis in DJES rat model. Although it may require further clinical studies in the near future, the current study opens up the possibilities for the use of the metalloproteinase inhibitor, BB-94, in the treatment of multiple organ hemorrhagic injuries in DJES. Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.

Simultaneous measurements of jellyfish bell kinematics and flow fields using PTV and PIV

NASA Astrophysics Data System (ADS)

Xu, Nicole; Dabiri, John

2016-11-01

A better understanding of jellyfish swimming can potentially improve the energy efficiency of aquatic vehicles or create biomimetic robots for ocean monitoring. Aurelia aurita is a simple oblate invertebrate composed of a flexible bell and coronal muscle, which contracts to eject water from the subumbrellar volume. Jellyfish locomotion can be studied by obtaining body kinematics or by examining the resulting fluid velocity fields using particle image velocimetry (PIV). Typically, swim kinematics are obtained by semi-manually tracking points of interest (POI) along the bell in video post-processing; simultaneous measurements of kinematics and flows involve using this semi-manual tracking method on PIV videos. However, we show that both the kinematics and flow fields can be directly visualized in 3D space by embedding phosphorescent particles in animals free-swimming in seeded environments. Particle tracking velocimetry (PTV) can then be used to calculate bell kinematics, such as pulse frequency, bell deformation, swim trajectories, and propulsive efficiency. By simultaneously tracking POI within the bell and collecting PIV data, we can further study the jellyfish's natural locomotive control mechanisms in conjunction with flow measurements. NSF GRFP.

Feeding currents of the upside down jellyfish in the presence of background flow.

PubMed

Hamlet, Christina L; Miller, Laura A

2012-11-01

The upside-down jellyfish (Cassiopea spp.) is an ideal organism for examining feeding and exchange currents generated by bell pulsations due to its relatively sessile nature. Previous experiments and numerical simulations have shown that the oral arms play an important role in directing new fluid into the bell from along the substrate. All of this work, however, has considered the jellyfish in the absence of background flow, but the natural environments of Cassiopea and other cnidarians are dynamic. Flow velocities and directions fluctuate on multiple time scales, and mechanisms of particle capture may be fundamentally different in moving fluids. In this paper, the immersed boundary method is used to simulate a simplified jellyfish in flow. The elaborate oral arm structure is modeled as a homogenous porous layer. The results show that the oral arms trap vortices as they form during contraction and expansion of the bell. For constant flow conditions, the vortices are directed gently across the oral arms where particle capture occurs. For variable direction flows, the secondary structures change the overall pattern of the flow around the bell and appear to stabilize regions of mixing around the secondary mouths.

Structural and physical properties of collagen extracted from moon jellyfish under neutral pH conditions.

PubMed

Miki, Ayako; Inaba, Satomi; Baba, Takayuki; Kihira, Koji; Fukada, Harumi; Oda, Masayuki

2015-01-01

We extracted collagen from moon jellyfish under neutral pH conditions and analyzed its amino acid composition, secondary structure, and thermal stability. The content of hydroxyproline was 4.3%, which is lower than that of other collagens. Secondary structure analysis using circular dichroism (CD) showed a typical collagen helix. The thermal stability of this collagen at pH 3.0 was lower than those from fish scale and pig skin, which also correlates closely with jellyfish collagen having lower hydroxyproline content. Because the solubility of jellyfish collagen used in this study at neutral pH was quite high, it was possible to analyze its structural and physical properties under physiological conditions. Thermodynamic analysis using CD and differential scanning calorimetry showed that the thermal stability at pH 7.5 was higher than at pH 3.0, possibly due to electrostatic interactions. During the process of unfolding, fibrillation would occur only at neutral pH.

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

PubMed Central

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

2012-01-01

Objectives 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. Methods 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. Results The mean maximum D and V of the coagulations in Group A-2 (4.7 cm and 33.1 cm3, respectively) were significantly larger than those in Group A-1 (4.1 cm and 20.3 cm3, 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 cm3, 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). Conclusion 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. PMID:22422385

Effects of collagen and collagen hydrolysate from jellyfish umbrella on histological and immunity changes of mice photoaging.

PubMed

Fan, Jian; Zhuang, Yongliang; Li, Bafang

2013-01-17

Jellyfish collagen (JC) was extracted from jellyfish umbrella and hydrolyzed to prepare jellyfish collagen hydrolysate (JCH). The effects of JC and JCH on UV-induced skin damage of mice were evaluated by the skin moisture, microscopic analyses of skin and immunity indexes. The skin moisture analyses showed that moisture retention ability of UV-induced mice skin was increased by JC and JCH. Further histological analysis showed that JC and JCH could repair the endogenous collagen and elastin protein fibers, and could maintain the natural ratio of type I to type III collagen. The immunity indexes showed that JC and JCH play a role in enhancing immunity of photoaging mice in vivo. JCH showed much higher protective ability than JC. These results suggest that JCH as a potential novel antiphotoaging agent from natural resources.

Effects of Collagen and Collagen Hydrolysate from Jellyfish Umbrella on Histological and Immunity Changes of Mice Photoaging

PubMed Central

Fan, Jian; Zhuang, Yongliang; Li, Bafang

2013-01-01

Jellyfish collagen (JC) was extracted from jellyfish umbrella and hydrolyzed to prepare jellyfish collagen hydrolysate (JCH). The effects of JC and JCH on UV-induced skin damage of mice were evaluated by the skin moisture, microscopic analyses of skin and immunity indexes. The skin moisture analyses showed that moisture retention ability of UV-induced mice skin was increased by JC and JCH. Further histological analysis showed that JC and JCH could repair the endogenous collagen and elastin protein fibers, and could maintain the natural ratio of type I to type III collagen. The immunity indexes showed that JC and JCH play a role in enhancing immunity of photoaging mice in vivo. JCH showed much higher protective ability than JC. These results suggest that JCH as a potential novel antiphotoaging agent from natural resources. PMID:23344251

Actuation control of a PiezoMEMS biomimetic robotic jellyfish

NASA Astrophysics Data System (ADS)

Alejandre, Alvaro; Olszewski, Oskar; Jackson, Nathan

2017-06-01

Biomimetic micro-robots try to mimic the motion of a living system in the form of a synthetically developed microfabricated device. Dynamic motion of living systems have evolved through the years, but trying to mimic these motions is challenging. Micro-robotics are particular challenging as the fabrication of devices and controlling the motion in 3 dimensions is difficult. However, micro-scale robotics have potential to be used in a wide range of applications. MEMS based robots that can move and function in a liquid environment is of particular interest. This paper describes the development of a piezoMEMS based device that mimics the movement of a jellyfish. The paper focuses on the development of a finite element model that investigates a method of controlling the individual piezoelectric beams in order to create a jet propulsion motion, consisting of a quick excitation pulse followed by a slow recovery pulse in order to maximize thrust and velocity. By controlling the individual beams or legs of the jellyfish robot the authors can control the robot to move precisely in 3 dimensions.

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

Jellyfish prediction of occurrence from remote sensing data and a non-linear pattern recognition approach

NASA Astrophysics Data System (ADS)

Albajes-Eizagirre, Anton; Romero, Laia; Soria-Frisch, Aureli; Vanhellemont, Quinten

2011-11-01

Impact of jellyfish in human activities has been increasingly reported worldwide in recent years. Segments such as tourism, water sports and leisure, fisheries and aquaculture are commonly damaged when facing blooms of gelatinous zooplankton. Hence the prediction of the appearance and disappearance of jellyfish in our coasts, which is not fully understood from its biological point of view, has been approached as a pattern recognition problem in the paper presented herein, where a set of potential ecological cues was selected to test their usefulness for prediction. Remote sensing data was used to describe environmental conditions that could support the occurrence of jellyfish blooms with the aim of capturing physical-biological interactions: forcing, coastal morphology, food availability, and water mass characteristics are some of the variables that seem to exert an effect on jellyfish accumulation on the shoreline, under specific spatial and temporal windows. A data-driven model based on computational intelligence techniques has been designed and implemented to predict jellyfish events on the beach area as a function of environmental conditions. Data from 2009 over the NW Mediterranean continental shelf have been used to train and test this prediction protocol. Standard level 2 products are used from MODIS (NASA OceanColor) and MERIS (ESA - FRS data). The procedure for designing the analysis system can be described as following. The aforementioned satellite data has been used as feature set for the performance evaluation. Ground truth has been extracted from visual observations by human agents on different beach sites along the Catalan area. After collecting the evaluation data set, the performance between different computational intelligence approaches have been compared. The outperforming one in terms of its generalization capability has been selected for prediction recall. Different tests have been conducted in order to assess the prediction capability of the

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.

Efficacy of Venom from Tentacle of Jellyfish Stomolophus meleagris (Nemopilema nomurai) against the Cotton Bollworm Helicoverpa armigera

PubMed Central

Yu, Huahua; Li, Rongfeng; Dong, Xiangli; Xing, Ronge; Liu, Song; Li, Pengcheng

2014-01-01

Efficacy of venom from tentacle of jellyfish Stomolophus meleagris against the cotton bollworm Helicoverpa armigera was determined. Venom from tentacle of jellyfish Stomolophus meleagris could inhibit the growth of Helicoverpa armigera and the weight inhibiting rate of sample NFr-2 was 60.53%. Of the six samples, only NFr-2 had high insecticidal activity against Helicoverpa armigera and the corrected mortality recorded at 7 d was 74.23%. PMID:25162008

Isolation, Characterization and Evaluation of Collagen from Jellyfish Rhopilema esculentum Kishinouye for Use in Hemostatic Applications.

PubMed

Cheng, Xiaochen; Shao, Ziyu; Li, Chengbo; Yu, Lejun; Raja, Mazhar Ali; Liu, Chenguang

2017-01-01

Hemostat has been a crucial focus since human body is unable to control massive blood loss, and collagen proves to be an effective hemostat in previous studies. In this study, collagen was isolated from the mesoglea of jellyfish Rhopilema esculentum Kishinouye and its hemostatic property was studied. The yields of acid-soluble collagen (ASC) and pepsin-soluble (PSC) were 0.12% and 0.28% respectively. The SDS-PAGE patterns indicated that the collagen extracted from jellyfish mesoglea was type I collagen. The lyophilized jellyfish collagen sponges were cross-linked with EDC and interconnected networks in the sponges were revealed by scanning electron microscope (SEM). Collagen sponges exhibited higher water absorption rates than medical gauze and EDC/NHS cross-linking method could improve the stability of the collagen sponges. Compared with medical gauze groups, the blood clotting indexes (BCIs) of collagen sponges were significantly decreased (P < 0.05) and the concentration of collagen also had an influence on the hemostatic property (P < 0.05). Collagen sponges had an improved hemostatic ability compared to the gauze control in tail amputation rat models. Hemostatic mechanism studies showed that hemocytes and platelets could adhere and aggregate on the surface of collagen sponge. All properties make jellyfish collagen sponge to be a suitable candidate used as hemostatic material and for wound healing applications.

Isolation, Characterization and Evaluation of Collagen from Jellyfish Rhopilema esculentum Kishinouye for Use in Hemostatic Applications

PubMed Central

Cheng, Xiaochen; Liu, Chenguang

2017-01-01

Hemostat has been a crucial focus since human body is unable to control massive blood loss, and collagen proves to be an effective hemostat in previous studies. In this study, collagen was isolated from the mesoglea of jellyfish Rhopilema esculentum Kishinouye and its hemostatic property was studied. The yields of acid-soluble collagen (ASC) and pepsin-soluble (PSC) were 0.12% and 0.28% respectively. The SDS-PAGE patterns indicated that the collagen extracted from jellyfish mesoglea was type I collagen. The lyophilized jellyfish collagen sponges were cross-linked with EDC and interconnected networks in the sponges were revealed by scanning electron microscope (SEM). Collagen sponges exhibited higher water absorption rates than medical gauze and EDC/NHS cross-linking method could improve the stability of the collagen sponges. Compared with medical gauze groups, the blood clotting indexes (BCIs) of collagen sponges were significantly decreased (P < 0.05) and the concentration of collagen also had an influence on the hemostatic property (P < 0.05). Collagen sponges had an improved hemostatic ability compared to the gauze control in tail amputation rat models. Hemostatic mechanism studies showed that hemocytes and platelets could adhere and aggregate on the surface of collagen sponge. All properties make jellyfish collagen sponge to be a suitable candidate used as hemostatic material and for wound healing applications. PMID:28103327

Fatal and severe box jellyfish stings, including Irukandji stings, in Malaysia, 2000-2010.

PubMed

Lippmann, John M; Fenner, Peter J; Winkel, Ken; Gershwin, Lisa-Ann

2011-01-01

Jellyfish are a common cause of injury throughout the world, with fatalities and severe systemic events not uncommon after tropical stings. The internet is a recent innovation to gain information on real-time health issues of travel destinations, including Southeast Asia. We applied the model of internet-based retrospective health data aggregation, through the Divers Alert Network Asia-Pacific (DAN AP), together with more conventional methods of literature and media searches, to document the health significance, and clinical spectrum, of box jellyfish stings in Malaysia for the period January 1, 2000 to July 30, 2010. Three fatalities, consistent with chirodropid envenomation, were identified for the period-all tourists to Malaysia. Non-fatal chirodropid stings were also documented. During 2010, seven cases consistent with moderately severe Irukandji syndrome were reported to DAN and two representative cases are discussed here. Photographs of chirodropid (multi-tentacled), carybdeid (four-tentacled) box jellyfish, and of severe sting lesions were also submitted to DAN during this period. This study suggests that the frequency and severity of jellyfish stings affecting tourists in Southeast Asia have been significantly underestimated. Severe and fatal cases of chirodropid-type stings occur in coastal waters off Peninsular Malaysia and Sabah, Borneo. Indeed, the first Malaysian cases consistent with Irukandji-like syndrome are reported here. Reports to DAN, a provider of emergency advice to divers, offer one method to address the historic lack of formalized reporting mechanisms for such events, for photo-documentation of the possible culprit species and treatment advice. The application of marine stinger prevention and treatment principles throughout the region may help reduce the incidence and severity of such stings. Meanwhile travelers and their medical advisors should be aware of the hazards of these stings throughout the Asia-Pacific. © 2011 International

The Jellyfish: smart electro-active polymers for an autonomous distributed sensing node

NASA Astrophysics Data System (ADS)

Blottman, John B.; Richards, Roger T.

2006-05-01

The US Navy has recently placed emphasis on deployable, distributed sensors for Force Protection, Anti-Terrorism and Homeland Defense missions. The Naval Undersea Warfare Center has embarked on the development of a self-contained deployable node that is composed of electro-active polymers (EAP) for use in a covert persistent distributed surveillance system. Electro-Active Polymers (EAP) have matured to a level that permits their application in energy harvesting, hydrophones, electro-elastic actuation and electroluminescence. The problem to resolve is combining each of these functions into an autonomous sensing platform. The concept presented here promises an operational life several orders of magnitude beyond what is expected of a Sonobuoy due to energy conservation and harvesting, and at a reasonable cost. The embodiment envisioned is that of a deployed device resembling a jellyfish, made in most part of polymers, with the body encapsulating the necessary electronic processing and communications package and the tentacles of the jellyfish housing the sonar sensors. It will be small, neutrally buoyant, and will survey the water column much in the manner of a Cartesian Diver. By using the Electro-Active Polymers as artificial muscles, the motion of the jellyfish can be finely controlled. An increased range of detection and true node autonomy is achieved through volumetric array beamforming to focus the direction of interrogation and to null-out extraneous ambient noise.

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

Optimization of antioxidant activity by response surface methodology in hydrolysates of jellyfish (Rhopilema esculentum) umbrella collagen.

PubMed

Zhuang, Yong-liang; Zhao, Xue; Li, Ba-fang

2009-08-01

To optimize the hydrolysis conditions to prepare hydrolysates of jellyfish umbrella collagen with the highest hydroxyl radical scavenging activity, collagen extracted from jellyfish umbrella was hydrolyzed with trypsin, and response surface methodology (RSM) was applied. The optimum conditions obtained from experiments were pH 7.75, temperature (T) 48.77 degrees C, and enzyme-to-substrate ratio ([E]/[S]) 3.50%. The analysis of variance in RSM showed that pH and [E]/[S] were important factors that significantly affected the process (P<0.05 and P<0.01, respectively). The hydrolysates of jellyfish umbrella collagen were fractionated by high performance liquid chromatography (HPLC), and three fractions (HF-1>3000 Da, 1000 Da

Optimization of antioxidant activity by response surface methodology in hydrolysates of jellyfish (Rhopilema esculentum) umbrella collagen*

PubMed Central

Zhuang, Yong-liang; Zhao, Xue; Li, Ba-fang

2009-01-01

To optimize the hydrolysis conditions to prepare hydrolysates of jellyfish umbrella collagen with the highest hydroxyl radical scavenging activity, collagen extracted from jellyfish umbrella was hydrolyzed with trypsin, and response surface methodology (RSM) was applied. The optimum conditions obtained from experiments were pH 7.75, temperature (T) 48.77 °C, and enzyme-to-substrate ratio ([E]/[S]) 3.50%. The analysis of variance in RSM showed that pH and [E]/[S] were important factors that significantly affected the process (P<0.05 and P<0.01, respectively). The hydrolysates of jellyfish umbrella collagen were fractionated by high performance liquid chromatography (HPLC), and three fractions (HF-1>3000 Da, 1000 Da

Predicting the Presence of Scyphozoan Jellyfish in the Gulf of Mexico Using a Biophysical Model

NASA Astrophysics Data System (ADS)

Aleksa, K. T.; Nero, R. W.; Wiggert, J. D.; Graham, W. M.

2016-02-01

The study and quantification of jellyfish (cnidarian medusae and ctenophores) is difficult due to their fragile body plan and a composition similar to their environment. The development of a predictive biophysical jellyfish model would be the first of its kind for the Gulf of Mexico and could provide assistance in ecological research and human interactions. In this study, the collection data of two scyphozoan medusae, Chrysaora quinquecirrha and Aurelia spp., were extracted from SEAMAP trawling surveys and were used to determine biophysical predictors for the presence of large jellyfish medusae in the Gulf of Mexico. Both in situ and remote sensing measurements from 2003 to 2013 were obtained. Logistic regressions were then applied to 27 biophysical parameters derived from these data to explore and determine significant predictors for the presence of medusae. Significant predictors identified by this analysis included water temperature, chlorophyll a, turbidity, distance from shore, and salinity. Future application for this model include foraging assessment of gelatinous predators as well as possible near real time monitoring of the distribution and movement of these medusae in the Gulf of Mexico.

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.

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.

Computer memory: the LLL experience. [Octopus computer network

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fletcher, J.G.

1976-02-01

Those aspects of Octopus computer network design are reviewed that relate to memory and storage. Emphasis is placed on the difficulties and problems that arise because of the limitations of present storage devices, and indications are made of the directions in which technological advance could be of most value. (auth)

[Jellyfish and poison-producing animals that endanger swimmers].

PubMed

Litschauer-Poursadrollah, M; Mayer, D E; Hemmer, W; Jarisch, R

2010-05-01

Exposure to fresh water as well as to sea water can cause unpleasant consequences. The water of lakes or biotopes may be the reason for severe itching reactions on exposed skin, caused by cercariae. Exposure to seawater may lead to skin affections including itching or burning urticarial lesions as well as life threatening reactions. The causes for these reactions are especially species of jellyfish. (c) Georg Thieme Verlag KG Stuttgart. New York.

Comparison of Octopus Semi-Automated Kinetic Perimetry and Humphrey Peripheral Static Perimetry in Neuro-Ophthalmic Cases

PubMed Central

Rowe, Fiona J.; Noonan, Carmel; Manuel, Melanie

2013-01-01

Aim. To compare semikinetic perimetry (SKP) on Octopus 900 perimetry to a peripheral static programme with Humphrey automated perimetry. Methods. Prospective cross-section study comparing Humphrey full field (FF) 120 two zone programme to a screening protocol for SKP on Octopus perimetry. Results were independently graded for presence/absence of field defect plus type and location of defect. Results. 64 patients (113 eyes) underwent dual perimetry assessment. Mean duration of assessment for SKP was 4.54 minutes ±0.18 and 6.17 ± 0.12 for FF120 (P = 0.0001). 80% of results were correctly matched for normal or abnormal visual fields using the I4e target versus FF120, and 73.5% were correctly matched using the I2e target versus FF120. When comparing Octopus results with combined I4e and I2e isopters to the FF120 result, a match for normal or abnormal fields was recorded in 87%. Conclusions. Humphrey perimetry test duration was generally longer than Octopus SKP. In the absence of kinetic perimetry, peripheral static suprathreshold programme options such as FF120 may be useful for detection of visual field defects. However, statokinetic dissociation may occur. Octopus SKP utilising both I4e and I2e targets provides detailed information of both the defect depth and size and may provide a more representative view of the actual visual field defect. PMID:24558605

Problem solving ability of Octopus vulgaris Lamarck (Mollusca, Cephalopoda).

PubMed

Fiorito, G; von Planta, C; Scotto, P

1990-03-01

Experiments presented in this study show that Octopus vulgaris Lamarck is able to open transparent glass jars closed with a plastic plug and containing a live crab (Carcinus mediterraneus). The animals remove the plus (Operandum: O) and seize the crab (Predation :P) in one single attack. The number of unsuccessful attacks appears to decrease over a series of trials (p less than .01); during the same period exploration time remains unchanged. There is a statistically significant increase in performance over trials for O (p less than .01) and P (p less than .05) mean times analyzed by single factor ANOVA, suggesting that the learning process is accomplished either by stimulus-response association or by trial and error. We propose that Octopus vulgaris is capable of learning the solutions of both problems, Operandum and Predation, thus showing a highly developed ability of "integration" of the behavioral program.

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

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. (PsycINFO Database Record (c) 2014 APA, all rights reserved).

The magnitude of severe box jellyfish cases on Koh Samui and Koh Pha-ngan in the Gulf of Thailand.

PubMed

Thaikruea, Lakkana; Siriariyaporn, Potjaman

2016-02-17

Despite recent deaths caused by box jellyfish envenomation occurring on the islands of Samui and Pha-ngan in the Gulf of Thailand, many people do not believe box jellyfish can kill humans and many people dismiss the problem as insignificant. More evidence has been requested from the communities in order to evaluate the need for and the implementation of sustainable prevention measures. We aimed to determine the magnitude of cases of severe stinging by box jellyfish and describe the characteristics of these cases on the islands of Samui and Pha-ngan in Surat Thani Province from 1997 to 2015. Various strategies were integrated prospectively. Toxic jellyfish networks and surveillance system were established. Outbreak investigations were conducted retrospectively and prospectively from 2008 to 2015. There were 15 box jellyfish cases. A small majority of them were women (60.0) with a median age of 26.0 years (range 5.0-45.0 years). The highest incidence by month were August (33.3%), September and October (20.0%), and July (13.3%). Eight cases occurred on Samui (53.3%), 6 cases on Pha-ngan island (40.0%), and one case on the boat. All cases developed symptoms and signs immediately after being stung. More than half of the cases were unconscious. There were six fatal cases (46.7%). The wound characteristics had an appearance similar to caterpillar tracks or step ladder-like burn marks. Almost all cases involved Chirodropidae. One fatal case received fresh water and ice packs applied to the wounds (16.7%). Among the cases with known first aid, only one out of six fatal cases had vinegar applied to the wounds (16.7%), while haft of six surviving cases received the vinegar treatment. The islands of Samui and Pha-ngan have the highest incidence of fatal and near fatal box jellyfish cases in Thailand. There is an urgent need for informed pre-clinical emergent care. Optimal pre-clinical care is an area of active research.

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

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.

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.

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

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.

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.

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. Copyright © 2012 Elsevier Ltd. All rights reserved.

[Molecular identification and detection of moon jellyfish (Aurelia sp.) based on partial sequencing of mitochondrial 16S rDNA and COI].

PubMed

Wang, Jian-Yan; Zhen, Yu; Wang, Guo-shan; Mi, Tie-Zhu; Yu, Zhi-gang

2013-03-01

Taking the moon jellyfish Aurelia sp. commonly found in our coastal sea areas as test object, its genome DNA was extracted, the partial sequences of mt-16S rDNA (650 bp) and mt-COI (709 bp) were PCR-amplified, and, after purification, cloning, and sequencing, the sequences obtained were BLASTn-analyzed. The sequences of greater difference with those of the other jellyfish were chosen, and eight specific primers for the mt-16S rDNA and mt-COI of Aurelia sp. were designed, respectively. The specificity test indicated that the primer AS3 for the mt-16S rDNA and the primer AC3 for the mt-COI were excellent in rapidly detecting the target jellyfish from Rhopilema esculentum, Nemopilema nomurai, Cyanea nozakii, Acromitus sp., and Aurelia sp., and thus, the techniques for the molecular identification and detection of moon jellyfish were preliminarily established, which could get rid of the limitations in classical morphological identification of Aurelia sp. , being able to find the Aurelia sp. in the samples more quickly and accurately.

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.

A sting from an unknown jellyfish species associated with persistent symptoms and raised troponin I levels.

PubMed

McD Taylor, David; Pereira, Peter; Seymour, Jamie; Winkel, Kenneth D

2002-06-01

We describe a patient stung by an unknown jellyfish species offshore in Far North Queensland. The sting caused immediate and severe pain, multiple whip-like skin lesions and constitutional symptoms. The jellyfish tentacular nematocysyts were similar to, but distinct from, those of Carukia barnesi, a cause of the 'Irukandji' syndrome. The patients symptoms largely resolved over seven months and were associated with elevated cardiac troponin levels, in the absence of other evidence of cardiac disease. This case highlights the envenomation risks associated with marine recreation, and the need for critical evaluation of cardiac troponin assays and for further research in marine toxicology.

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

Comparative analysis of methods for concentrating venom from jellyfish Rhopilema esculentum Kishinouye

NASA Astrophysics Data System (ADS)

Li, Cuiping; Yu, Huahua; Feng, Jinhua; Chen, Xiaolin; Li, Pengcheng

2009-02-01

In this study, several methods were compared for the efficiency to concentrate venom from the tentacles of jellyfish Rhopilema esculentum Kishinouye. The results show that the methods using either freezing-dry or gel absorption to remove water to concentrate venom are not applicable due to the low concentration of the compounds dissolved. Although the recovery efficiency and the total venom obtained using the dialysis dehydration method are high, some proteins can be lost during the concentrating process. Comparing to the lyophilization method, ultrafiltration is a simple way to concentrate the compounds at high percentage but the hemolytic activities of the proteins obtained by ultrafiltration appear to be lower. Our results suggest that overall lyophilization is the best and recommended method to concentrate venom from the tentacles of jellyfish. It shows not only the high recovery efficiency for the venoms but high hemolytic activities as well.

Use of octopus as a bioindicator species: Baseline studies

DOE Office of Scientific and Technical Information (OSTI.GOV)

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

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 valuesmore » 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.« less

Nearly automatic motion capture system for tracking octopus arm movements in 3D space.

PubMed

Zelman, Ido; Galun, Meirav; Akselrod-Ballin, Ayelet; Yekutieli, Yoram; Hochner, Binyamin; Flash, Tamar

2009-08-30

Tracking animal movements in 3D space is an essential part of many biomechanical studies. The most popular technique for human motion capture uses markers placed on the skin which are tracked by a dedicated system. However, this technique may be inadequate for tracking animal movements, especially when it is impossible to attach markers to the animal's body either because of its size or shape or because of the environment in which the animal performs its movements. Attaching markers to an animal's body may also alter its behavior. Here we present a nearly automatic markerless motion capture system that overcomes these problems and successfully tracks octopus arm movements in 3D space. The system is based on three successive tracking and processing stages. The first stage uses a recently presented segmentation algorithm to detect the movement in a pair of video sequences recorded by two calibrated cameras. In the second stage, the results of the first stage are processed to produce 2D skeletal representations of the moving arm. Finally, the 2D skeletons are used to reconstruct the octopus arm movement as a sequence of 3D curves varying in time. Motion tracking, segmentation and reconstruction are especially difficult problems in the case of octopus arm movements because of the deformable, non-rigid structure of the octopus arm and the underwater environment in which it moves. Our successful results suggest that the motion-tracking system presented here may be used for tracking other elongated objects.

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.

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.

Global Transcriptome Analysis of the Tentacle of the Jellyfish Cyanea capillata Using Deep Sequencing and Expressed Sequence Tags: Insight into the Toxin- and Degenerative Disease-Related Transcripts

PubMed Central

Liu, Dan; Wang, Qianqian; Ruan, Zengliang; He, Qian; Zhang, Liming

2015-01-01

Background Jellyfish contain diverse toxins and other bioactive components. However, large-scale identification of novel toxins and bioactive components from jellyfish has been hampered by the low efficiency of traditional isolation and purification methods. Results We performed de novo transcriptome sequencing of the tentacle tissue of the jellyfish Cyanea capillata. A total of 51,304,108 reads were obtained and assembled into 50,536 unigenes. Of these, 21,357 unigenes had homologues in public databases, but the remaining unigenes had no significant matches due to the limited sequence information available and species-specific novel sequences. Functional annotation of the unigenes also revealed general gene expression profile characteristics in the tentacle of C. capillata. A primary goal of this study was to identify putative toxin transcripts. As expected, we screened many transcripts encoding proteins similar to several well-known toxin families including phospholipases, metalloproteases, serine proteases and serine protease inhibitors. In addition, some transcripts also resembled molecules with potential toxic activities, including cnidarian CfTX-like toxins with hemolytic activity, plancitoxin-1, venom toxin-like peptide-6, histamine-releasing factor, neprilysin, dipeptidyl peptidase 4, vascular endothelial growth factor A, angiotensin-converting enzyme-like and endothelin-converting enzyme 1-like proteins. Most of these molecules have not been previously reported in jellyfish. Interestingly, we also characterized a number of transcripts with similarities to proteins relevant to several degenerative diseases, including Huntington’s, Alzheimer’s and Parkinson’s diseases. This is the first description of degenerative disease-associated genes in jellyfish. Conclusion We obtained a well-categorized and annotated transcriptome of C. capillata tentacle that will be an important and valuable resource for further understanding of jellyfish at the molecular

Global Transcriptome Analysis of the Tentacle of the Jellyfish Cyanea capillata Using Deep Sequencing and Expressed Sequence Tags: Insight into the Toxin- and Degenerative Disease-Related Transcripts.

PubMed

Liu, Guoyan; Zhou, Yonghong; Liu, Dan; Wang, Qianqian; Ruan, Zengliang; He, Qian; Zhang, Liming

2015-01-01

Jellyfish contain diverse toxins and other bioactive components. However, large-scale identification of novel toxins and bioactive components from jellyfish has been hampered by the low efficiency of traditional isolation and purification methods. We performed de novo transcriptome sequencing of the tentacle tissue of the jellyfish Cyanea capillata. A total of 51,304,108 reads were obtained and assembled into 50,536 unigenes. Of these, 21,357 unigenes had homologues in public databases, but the remaining unigenes had no significant matches due to the limited sequence information available and species-specific novel sequences. Functional annotation of the unigenes also revealed general gene expression profile characteristics in the tentacle of C. capillata. A primary goal of this study was to identify putative toxin transcripts. As expected, we screened many transcripts encoding proteins similar to several well-known toxin families including phospholipases, metalloproteases, serine proteases and serine protease inhibitors. In addition, some transcripts also resembled molecules with potential toxic activities, including cnidarian CfTX-like toxins with hemolytic activity, plancitoxin-1, venom toxin-like peptide-6, histamine-releasing factor, neprilysin, dipeptidyl peptidase 4, vascular endothelial growth factor A, angiotensin-converting enzyme-like and endothelin-converting enzyme 1-like proteins. Most of these molecules have not been previously reported in jellyfish. Interestingly, we also characterized a number of transcripts with similarities to proteins relevant to several degenerative diseases, including Huntington's, Alzheimer's and Parkinson's diseases. This is the first description of degenerative disease-associated genes in jellyfish. We obtained a well-categorized and annotated transcriptome of C. capillata tentacle that will be an important and valuable resource for further understanding of jellyfish at the molecular level and information on the underlying

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Deng, H.; Manor, D.; Weng, G.

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 themore » 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.« less

Jellyfish venomics and venom gland transcriptomics analysis of Stomolophus meleagris to reveal the toxins associated with sting.

PubMed

Li, Rongfeng; Yu, Huahua; Xue, Wei; Yue, Yang; Liu, Song; Xing, Ronge; Li, Pengcheng

2014-06-25

Jellyfish Stomolophus meleagris is a very dangerous animal because of its strong toxicity. However, the composition of the venom is still unclear. Both proteomics and transcriptomics approaches were applied in present study to investigate the major components and their possible relationships to the sting. The proteomics of the venom from S. meleagris was conducted by tryptic digestion of the crude venom followed by RP-HPLC separation and MS/MS analysis of the tryptic peptides. The venom gland transcriptome was analyzed using a high-throughput Illumina sequencing platform HiSeq 2000 with de novo assembly. A total of 218 toxins were identified including C-type lectin, phospholipase A₂ (PLA₂), potassium channel inhibitor, protease inhibitor, metalloprotease, hemolysin and other toxins, most of which should be responsible for the sting. Among them, serine protease inhibitor, PLA₂, potassium channel inhibitor and metalloprotease are predominant, representing 28.44%, 21.56%, 16.06% and 15.14% of the identified venom proteins, respectively. Overall, our combined proteomics and transcriptomics approach provides a systematic overview of the toxins in the venom of jellyfish S. meleagris and it will be significant to understand the mechanism of the sting. Jellyfish Stomolophus meleagris is a very dangerous animal because of its strong toxicity. It often bloomed in the coast of China in recent years and caused thousands of people stung and even deaths every year. However, the components which caused sting are still unknown yet. In addition, no study about the venomics of jellyfish S. meleagris has been reported. In the present study, both proteomics and transcriptomics approaches were applied to investigate the major components related to the sting. The result showed that major component included C-type lectin, phospholipase A₂, potassium channel inhibitor, protease inhibitor, metalloprotease, hemolysin and other toxins, which should be responsible for the effect of

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.

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.

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.

Antibacterial polyketides from the jellyfish-derived fungus Paecilomyces variotii.

PubMed

Liu, Juan; Li, Famei; Kim, Eun La; Li, Jian Lin; Hong, Jongki; Bae, Kyung Sook; Chung, Hae Young; Kim, Hyung Sik; Jung, Jee H

2011-08-26

Four new polyketides (1-4) were isolated from the fungus Paecilomyces variotii, which was derived from the jellyfish Nemopilema nomurai. The planar structures and relative configurations of these polyketides were elucidated on the basis of spectroscopic analyses, including 2D NMR experiments. The compounds showed inhibitory activity against pathogenic bacteria including methicillin-resistant Staphylococcus aureus 3089 and multi-drug-resistant Vibrio parahemolyticus 7001 with MIC values in the range 5-40 μg/mL.

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'. © 2015. Published by The Company of Biologists Ltd.

Scyphozoan jellyfish's mesoglea supports attachment, spreading and migration of anthozoans' cells in vitro.

PubMed

Frank, U; Rinkevich, B

1999-01-01

Mechanically and enzymatically dissociated cells from five anthozoan species were laid on seven substrates in vitro. Cells were taken from two sea anemones (Aiptasia sp. and Anemonia sulcata), a scleractinian coral (Stylophora pistillata) and two alcyonacean corals (Heteroxenia fuscescence and Nephthea sp). Substrates tested: glass (coverslips), plastic (uncoated tissue culture plates), type IV collagen, gelatin, fibronectin, mesoglea pieces from the scyphozoan jellyfish Rhopilema nomadica and acetic acid extract of jellyfish mesoglea. Except for the mesoglea pieces, cells did not respond to any one of the other substrates, retaining their rounded shape. Following contact with mesoglea pieces, cells attached and spread. Subsequently they migrated into the mesogleal matrix at a rate of 5-10 microm/h during the first 2-5 h. No difference was found between the behavior of cells from the five different cnidarian species. Copyright 1999 Academic Press.

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.

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.

The homeobox gene Msx in development and transdifferentiation of jellyfish striated muscle.

PubMed

Galle, Sabina; Yanze, Nathalie; Seipel, Katja

2005-01-01

Bilaterian Msx homeobox genes are generally expressed in areas of cell proliferation and in association with multipotent progenitor cells. Likewise, jellyfish Msx is expressed in progenitor cells of the developing entocodon, a cell layer giving rise to the striated and smooth muscles of the medusa. However, in contrast to the bilaterian homologs, Msx gene expression is maintained at high levels in the differentiated striated muscle of the medusa in vivo and in vitro. This tissue exhibits reprogramming competence. Upon induction, the Msx gene is immediately switched off in the isolated striated muscle undergoing transdifferentiation, to be upregulated again in the emerging smooth muscle cells which, in a stem cell like manner, undergo quantal cell divisions producing two cell types, a proliferating smooth muscle cell and a differentiating nerve cell. This study indicates that the Msx protein may be a key component of the reprogramming machinery responsible for the extraordinary transdifferentation and regeneration potential of striated muscle in the hydrozoan jellyfish.

A gonad-expressed opsin mediates light-induced spawning in the jellyfish Clytia

PubMed Central

Quiroga Artigas, Gonzalo; Lapébie, Pascal; Leclère, Lucas; Takeda, Noriyo; Deguchi, Ryusaku; Jékely, Gáspár

2018-01-01

Across the animal kingdom, environmental light cues are widely involved in regulating gamete release, but the molecular and cellular bases of the photoresponsive mechanisms are poorly understood. In hydrozoan jellyfish, spawning is triggered by dark-light or light-dark transitions acting on the gonad, and is mediated by oocyte maturation-inducing neuropeptide hormones (MIHs) released from the ectoderm. We determined in Clytia hemisphaerica that blue-cyan light triggers spawning in isolated gonads. A candidate opsin (Opsin9) was found co-expressed with MIH within specialised ectodermal cells. Opsin9 knockout jellyfish generated by CRISPR/Cas9 failed to undergo oocyte maturation and spawning, a phenotype reversible by synthetic MIH. Gamete maturation and release in Clytia is thus regulated by gonadal photosensory-neurosecretory cells that secrete MIH in response to light via Opsin9. Similar cells in ancestral eumetazoans may have allowed tissue-level photo-regulation of diverse behaviours, a feature elaborated in cnidarians in parallel with expansion of the opsin gene family. PMID:29303477

To Pee, or Not to Pee: A Review on Envenomation and Treatment in European Jellyfish Species.

PubMed

Montgomery, Louise; Seys, Jan; Mees, Jan

2016-07-08

There is a growing cause for concern on envenoming European species because of jellyfish blooms, climate change and globalization displacing species. Treatment of envenomation involves the prevention of further nematocyst release and relieving local and systemic symptoms. Many anecdotal treatments are available but species-specific first aid response is essential for effective treatment. However, species identification is difficult in most cases. There is evidence that oral analgesics, seawater, baking soda slurry and 42-45 °C hot water are effective against nematocyst inhibition and giving pain relief. The application of topical vinegar for 30 s is effective on stings of specific species. Treatments, which produce osmotic or pressure changes can exacerbate the initial sting and aggravate symptoms, common among many anecdotal treatments. Most available therapies are based on weak evidence and thus it is strongly recommended that randomized clinical trials are undertaken. We recommend a vital increase in directed research on the effect of environmental factors on envenoming mechanisms and to establish a species-specific treatment. Adequate signage on jellyfish stings and standardized first aid protocols with emphasis on protective equipment and avoidance of jellyfish to minimize cases should be implemented in areas at risk.

To Pee, or Not to Pee: A Review on Envenomation and Treatment in European Jellyfish Species

PubMed Central

Montgomery, Louise; Seys, Jan; Mees, Jan

2016-01-01

There is a growing cause for concern on envenoming European species because of jellyfish blooms, climate change and globalization displacing species. Treatment of envenomation involves the prevention of further nematocyst release and relieving local and systemic symptoms. Many anecdotal treatments are available but species-specific first aid response is essential for effective treatment. However, species identification is difficult in most cases. There is evidence that oral analgesics, seawater, baking soda slurry and 42–45 °C hot water are effective against nematocyst inhibition and giving pain relief. The application of topical vinegar for 30 s is effective on stings of specific species. Treatments, which produce osmotic or pressure changes can exacerbate the initial sting and aggravate symptoms, common among many anecdotal treatments. Most available therapies are based on weak evidence and thus it is strongly recommended that randomized clinical trials are undertaken. We recommend a vital increase in directed research on the effect of environmental factors on envenoming mechanisms and to establish a species-specific treatment. Adequate signage on jellyfish stings and standardized first aid protocols with emphasis on protective equipment and avoidance of jellyfish to minimize cases should be implemented in areas at risk. PMID:27399728

Digestive enzymes of the Californian two-spot octopus, Octopus bimaculoides (Pickford and McConnaughey, 1949).

PubMed

Ibarra-García, Laura Elizabeth; Tovar-Ramírez, Dariel; Rosas, Carlos; Campa-Córdova, Ángel Isidro; Mazón-Suástegui, José Manuel

2018-01-01

Octopus bimaculoides is an important commercially fished species in the California Peninsula with aquaculture potential; however, to date limited information is available regarding its digestive physiology. The objective of this study was focused on biochemically characterizing the main enzymes involved in the digestion of O. bimaculoides. Optimum pH, temperature and thermostability were determined for amylases, lipases, trypsin and chymotrypsin; optimum pH and protease inhibitor effect were assessed for acidic and alkaline proteases, and the effect of divalent ions on trypsin and chymotrypsin activity was evaluated in enzymatic extracts from the digestive (DG) and salivary glands (SG) and crop gastric juices (GJ). High amylase activity was detected in GD and GJ whereas this activity is very low in other cephalopods. Salivary glands had the greatest activity in most of the enzyme groups, showing the importance of this organ in digestion. Optimum pH was different depending on the organ and enzyme analyzed. The optimum pH in DG was 3 showing the predominance of acidic proteases in the digestion process. All enzymes were resistant and stable at high temperatures in contrast with other marine species. Trypsin and chymotrypsin activity were highly incremented with the presence of Mg 2+ , Co 2+ , Cu 2+ and Zn 2+ in some tissues. The inhibitor assay showed the importance of serine proteases, metalloproteases and aspartic proteases in the digestive process of this species. This study is the first in assessing the main digestive enzymes of O. bimaculoides and in remarking the importance of other digestive enzyme groups besides proteases in octopuses. Copyright © 2017 Elsevier Inc. All rights reserved.

Isolation and in vitro partial characterization of hemolytic proteins from the nematocyst venom of the jellyfish Stomolophus meleagris.

PubMed

Li, Rongfeng; Yu, Huahua; Xing, Ronge; Liu, Song; Qing, Yukun; Li, Kecheng; Li, Bing; Meng, Xiangtao; Cui, Jinhui; Li, Pengcheng

2013-09-01

Jellyfish venom contains various toxins and can cause itching, edema, muscle aches, shortness of breath, blood pressure depression, shock or even death after being stung. Hemolytic protein is one of the most hazardous components in the venom. The present study investigated the hemolytic activity of the nematocyst venom from jellyfish Stomolophus meleagris. Anion exchange chromatography, DEAE Sepharose Fast Flow, and gel filtration chromatography, Superdex200 had been employed to isolate hemolytic proteins from the nematocyst venom of jellyfish S. meleagris. Hemolysis of chicken red blood cells was used to quantify hemolytic potency of crude nematocyst venom and chromatography fractions during the purification process. Native-PAGE profile displayed one protein band in the purified hemolytic protein (SmTX); however, two protein bands with apparent molecular weights of ≈ 45 kDa and 52 kDa were observed in the reducing SDS-PAGE analysis. Approximately 70 μg/mL of SmTX caused 50% hemolysis (HU50) of the erythrocyte suspension. The hemolytic activity of SmTX was shown to be temperature and pH dependent, with the optimum temperature and pH being 37°C and pH 5.0. The present study is the first report of isolation and partial characterization of hemolytic proteins from the nematocyst venom of the jellyfish S. meleagris. The mechanism of the hemolytic activity of SmTX is not clear and deserves further investigation. Copyright © 2013. Published by Elsevier Ltd.

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…

Clinical toxicology: a tropical Australian perspective.

PubMed

Currie, B J

2000-02-01

Tropical Australia has an amazing diversity of venomous fauna, from "the world's most venomous creature," the multi-tentacled (chirodropid) box jellyfish Chironex fleckeri, to aggressive spiders whose venom remains to be characterized. All genera of highly venomous Australasian elapid snakes are present, except for tiger snakes. Most notable is the taipan (Oxyuranus scutellatus), with the most efficient "snap-release" biting mechanism of any snake and venom components causing the full constellation of clinical envenoming features: coagulopathy from fibrinogen depletion (procoagulant), neurotoxicity (predominantly presynaptic neurotoxin) and rhabdomyolysis (myotoxin). Brown snakes (Pseudonaja textilis and P. nuchalis) now account for most snake bite fatalities in Australia, as a result of severe coagulopathy and a poorly defined early scenario of collapse, postulated to be caused by profound hypotension caused by transient myocardial dysfunction associated with prothrombin activation. Other venomous entities include paralyzing ticks, the blue-ringed octopus, stone fish and other marine animals with venomous spines, paralyzing cone shells, and a wide range of jellyfish including Carukia barnesi and possibly other four-tentacled (carybdeid) box jellyfish causing the Irukandji syndrome.

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. Copyright © 2011 Elsevier Ltd. All rights reserved.

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

Subducting Slabs: Jellyfishes in the Earth's Mantle

NASA Astrophysics Data System (ADS)

Loiselet, C.; Braun, J.; Husson, L.; Le Carlier de Veslud, C.; Thieulot, C.; Yamato, P.; Grujic, D.

2010-12-01

The constantly improving resolution of geophysical data, seismic tomography and seismicity in particular, shows that the lithosphere does not subduct as a slab of uniform thickness but is rather thinned in the upper mantle and thickened around the transition zone between the upper and lower mantle. This observation has traditionally been interpreted as evidence for the buckling and piling of slabs at the boundary between the upper and lower mantle, where a strong contrast in viscosity may exist and cause resistance to the penetration of slabs into the lower mantle. The distribution and character of seismicity reveal, however, that slabs undergo vertical extension in the upper mantle and compression near the transition zone. In this paper, we demonstrate that during the subduction process, the shape of low viscosity slabs (1 to 100 times more viscous than the surrounding mantle) evolves toward an inverted plume shape that we coin jellyfish. Results of a 3D numerical model show that the leading tip of slabs deform toward a rounded head skirted by lateral tentacles that emerge from the sides of the jellyfish head. The head is linked to the body of the subducting slab by a thin tail. A complete parametric study reveals that subducting slabs may achieve a variety of shapes, in good agreement with the diversity of natural slab shapes evidenced by seismic tomography. Our work also suggests that the slab to mantle viscosity ratio in the Earth is most likely to be lower than 100. However, the sensitivity of slab shapes to upper and lower mantle viscosities and densities, which remain poorly constrained by independent evidence, precludes any systematic deciphering of the observations.

Subducting slabs: Jellyfishes in the Earth's mantle

NASA Astrophysics Data System (ADS)

Loiselet, Christelle; Braun, Jean; Husson, Laurent; Le Carlier de Veslud, Christian; Thieulot, Cedric; Yamato, Philippe; Grujic, Djordje

2010-08-01

The constantly improving resolution of geophysical data, seismic tomography and seismicity in particular, shows that the lithosphere does not subduct as a slab of uniform thickness but is rather thinned in the upper mantle and thickened around the transition zone between the upper and lower mantle. This observation has traditionally been interpreted as evidence for the buckling and piling of slabs at the boundary between the upper and lower mantle, where a strong contrast in viscosity may exist and cause resistance to the penetration of slabs into the lower mantle. The distribution and character of seismicity reveal, however, that slabs undergo vertical extension in the upper mantle and compression near the transition zone. In this paper, we demonstrate that during the subduction process, the shape of low viscosity slabs (1 to 100 times more viscous than the surrounding mantle) evolves toward an inverted plume shape that we coin jellyfish. Results of a 3D numerical model show that the leading tip of slabs deform toward a rounded head skirted by lateral tentacles that emerge from the sides of the jellyfish head. The head is linked to the body of the subducting slab by a thin tail. A complete parametric study reveals that subducting slabs may achieve a variety of shapes, in good agreement with the diversity of natural slab shapes evidenced by seismic tomography. Our work also suggests that the slab to mantle viscosity ratio in the Earth is most likely to be lower than 100. However, the sensitivity of slab shapes to upper and lower mantle viscosities and densities, which remain poorly constrained by independent evidence, precludes any systematic deciphering of the observations.

Exploring single nucleotide polymorphism (SNP), microsatellite (SSR) and differentially expressed genes in the jellyfish (Rhopilema esculentum) by transcriptome sequencing.

PubMed

Li, Yunfeng; Zhou, Zunchun; Tian, Meilin; Tian, Yi; Dong, Ying; Li, Shilei; Liu, Weidong; He, Chongbo

2017-08-01

In this study, single nucleotide polymorphism (SNP), microsatellite (SSR) and differentially expressed genes (DEGs) in the oral parts, gonads, and umbrella parts of the jellyfish Rhopilema esculentum were analyzed by RNA-Seq technology. A total of 76.4 million raw reads and 72.1 million clean reads were generated from deep sequencing. Approximately 119,874 tentative unigenes and 149,239 transcripts were obtained. A total of 1,034,708 SNP markers were detected in the three tissues. For microsatellite mining, 5088 SSRs were identified from the unigene sequences. The most frequent repeat motifs were mononucleotide repeats, which accounted for 61.93%. Transcriptome comparison of the three tissues yielded a total of 8841 DEGs, of which 3560 were up-regulated and 5281 were down-regulated. This study represents the greatest sequencing effort carried out for a jellyfish and provides the first high-throughput transcriptomic resource for jellyfish. Copyright © 2017 Elsevier B.V. All rights reserved.

Octopus-toolkit: a workflow to automate mining of public epigenomic and transcriptomic next-generation sequencing data

PubMed Central

Kim, Taemook; Seo, Hogyu David; Hennighausen, Lothar; Lee, Daeyoup

2018-01-01

Abstract Octopus-toolkit is a stand-alone application for retrieving and processing large sets of next-generation sequencing (NGS) data with a single step. Octopus-toolkit is an automated set-up-and-analysis pipeline utilizing the Aspera, SRA Toolkit, FastQC, Trimmomatic, HISAT2, STAR, Samtools, and HOMER applications. All the applications are installed on the user's computer when the program starts. Upon the installation, it can automatically retrieve original files of various epigenomic and transcriptomic data sets, including ChIP-seq, ATAC-seq, DNase-seq, MeDIP-seq, MNase-seq and RNA-seq, from the gene expression omnibus data repository. The downloaded files can then be sequentially processed to generate BAM and BigWig files, which are used for advanced analyses and visualization. Currently, it can process NGS data from popular model genomes such as, human (Homo sapiens), mouse (Mus musculus), dog (Canis lupus familiaris), plant (Arabidopsis thaliana), zebrafish (Danio rerio), fruit fly (Drosophila melanogaster), worm (Caenorhabditis elegans), and budding yeast (Saccharomyces cerevisiae) genomes. With the processed files from Octopus-toolkit, the meta-analysis of various data sets, motif searches for DNA-binding proteins, and the identification of differentially expressed genes and/or protein-binding sites can be easily conducted with few commands by users. Overall, Octopus-toolkit facilitates the systematic and integrative analysis of available epigenomic and transcriptomic NGS big data. PMID:29420797

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.

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.

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

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.

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.

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

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.

Driving the Heliospheric Jellyfish

NASA Astrophysics Data System (ADS)

Leamon, R. J.; Mcintosh, S. W.

2016-12-01

Recent observational work has demonstrated that the enigmatic sunspotcycle and global magnetic environment of the Sun which source theeruptive events and modulate the solar wind, respectively, can beexplained in terms of the intra- and extra-hemispheric interaction ofmagnetic activity bands that belong to the 22-year magnetic polaritycycle. Those activity bands appear to be anchored deep in the Sun'sconvective interior and governed by the rotation of our star's radiativezone. We have also observed that those magnetic bands exhibit strongquasi-annual variability in the rotating convecting system which resultsin a significant local modulation of solar surface magnetism, forcingthe production of large eruptive events in each hemisphere that mouldsthe global-scale solar magnetic field and the solar-wind-inflatedheliosphere. Together with significant changes in the Sun's ultraviolet(UV), extreme ultraviolet (EUV), and X-Ray irradiance, these eruptivefluctuations ensnare all the Heliosphere (all of Heliophysics) like thetentacles of a jellyfish, and can be inferred in variations of suchwide-ranging phenomena as the South Atlantic Anomaly, the thermosphere,the radiation belts, and the can address ``Has Voyager left theHeliosphere?''

Speciation and isotopic composition of sulfur in sediments from Jellyfish Lake, Palau

USGS Publications Warehouse

Bates, A.L.; Spiker, E. C.; Orem, W.H.; Burnett, W.C.

1993-01-01

Jellyfish Lake, Palau, is a meromictic marine lake with high organic productivity, low reactive Fe content, and anoxic bottom waters. Sediment samples from Jellyfish Lake were examined for the distribution of sulfur species and their isotopic signatures in order to gain a better understanding of sedimentary sulfur incorporation in Fe-poor environments. Surface samples were taken along a transect from a near-shore site to the center of the lake, and include a sample below oxic water, a sample below the chemocline layer, and samples below anoxic waters. Three additional samples were taken from a core, 2 m long, collected near the lake center. Sulfur to organic carbon weight ratios in all samples were lower than the expected value of 0.36 for normal marine sediment, probably because the lake water is deficient in reactive Fe to form iron sulfides. Total sulfur contents in the surface sediments indicated no changes with distance from shore; however, the sulfur content of the surface sample at the chemocline layer may be slightly higher. Total sulfur content increased with depth in the core and is inversely related to organic carbon content. Organic sulfur is the major sulfur species in the samples, followed in descending order by sulfate, disulfides and monosulfides. Sulfate sulfur isotope ??34S-values are positive (from +20.56 to +12.04???), reflecting the marine source of sulfate in Jellyfish Lake. Disulfide and monosulfide ??34S-values are negative (from -25.07 to -7.60???), because of fractionation during bacterial reduction of sulfate. Monosulfide ??34S-values are somewhat higher than those of disulfides, and they are close to the ??34S-values of organic sulfur. These results indicate that most of the organic sulfur is formed by reaction of bacteriogenic monosulfides, or possibly monosulfide-derived polysulfides, with organic matter in the sediment. ?? 1993.

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.

JELLYFISH GALAXY CANDIDATES AT LOW REDSHIFT

DOE Office of Scientific and Technical Information (OSTI.GOV)

Poggianti, B. M.; Fasano, G.; Omizzolo, A.

Galaxies that are being stripped of their gas can sometimes be recognized from their optical appearance. Extreme examples of stripped galaxies are the so-called “jellyfish galaxies” that exhibit tentacles of debris material with a characteristic jellyfish morphology. We have conducted the first systematic search for galaxies that are being stripped of their gas at low-z (z = 0.04−0.07) in different environments, selecting galaxies with varying degrees of morphological evidence for stripping. We have visually inspected B- and V-band images and identified 344 candidates in 71 galaxy clusters of the OMEGAWINGS+WINGS sample and 75 candidates in groups and lower mass structuresmore » in the PM2GC sample. We present the atlas of stripping candidates and a first analysis of their environment and their basic properties, such as morphologies, star formation rates and galaxy stellar masses. Candidates are found in all clusters and at all clustercentric radii, and their number does not correlate with the cluster velocity dispersion σ or X-ray luminosity L{sub X}. Interestingly, convincing cases of candidates are also found in groups and lower mass halos (10{sup 11}−10{sup 14}M{sub ⊙}), although the physical mechanism at work needs to be securely identified. All the candidates are disky, have stellar masses ranging from log M/M{sub ⊙} < 9 to > 11.5 and the majority of them form stars at a rate that is on average a factor of 2 higher (2.5σ) compared to non-stripped galaxies of similar mass. The few post-starburst and passive candidates have weak stripping evidence. We conclude that disturbed morphologies suggestive of stripping phenomena are ubiquitous in clusters and could be present even in groups and low mass halos. Further studies will reveal the physics of the gas stripping and clarify the mechanisms at work.« less

Radioactivity in three species of eastern Mediterranean jellyfish.

PubMed

Mamish, S; Al-Masri, M S; Durgham, H

2015-11-01

Activity concentrations of (137)Cs, (40)K, (210)Po, (210)Pb, (234)U and (238)U were determined in umbrella and oral arms of three widely distributed jellyfish species; namely Rhopilema nomadica Galil, 1990, Aurelia aurita Linne, 1758 and Aequorea forskalea Péron & Lesueur, 1810 collected from February 2011 to January 2012 in four sampling locations along the Syrian coast (Eastern Mediterranean Sea). The results have shown significant variations in radionuclides activity concentrations amongst the species. The average activity concentrations of (40)K, (210)Po, (210)Pb, (234)U and (238)U in the umbrella of R. nomadica species were higher than the average activity concentrations in the umbrella of A. aurita species by about 3.2, 1.4, 1.8, 3.2 and 3.2 folds, and A. forskalea species by about 45.5, 15.4, 19, 7.4 and 7.6 folds, respectively. The average activity concentrations of (40)K, (210)Po, (210)Pb, (234)U and (238)U in oral arms of R. nomadica species were higher than the average activity concentrations in oral arms of A. aurita species by about 3.8, 1.7, 1.9, 2.8 and 2.9 folds, respectively. (137)Cs activity concentrations were below the detection limit in all measured samples. In addition, activity concentrations of (137)Cs, (40)K, (210)Po, (210)Pb, (234)U and (238)U were also determined in 44 surface seawater samples and the activity concentrations ranged between 10.6 and 11.9 Bq l(-1) for (40)K, 1.1 and 1.4 mBq l(-1) for (210)Po, 0.5 and 0.7 mBq l(-1) for (210)Pb, 40.8 and 44.5 mBq l(-1) for (234)U, and 36.9 and 38.4 mBq l(-1) for (238)U, while (137)Cs activity concentrations were below the detection limit in all measured samples. Moreover, the umbrella and oral arms readily accumulated (40)K, (210)Po, (210)Pb, (234)U and (238)U above ambient seawater levels in the sequence of (210)Po > (210)Pb > (4) K > (234)U and (238)U. Concentration ratio (CR) values were relatively high for (210)Po and (210)Pb and reached 10(3) and 10(2), respectively for the jellyfish R

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.

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

Hovering of a jellyfish-like flying machine

NASA Astrophysics Data System (ADS)

Ristroph, Leif; Childress, Stephen

2013-11-01

Ornithopters, or flapping-wing aircraft, offer an alternative to helicopters in achieving maneuverability at small scales, although stabilizing such aerial vehicles remains a key challenge. Here, we present a hovering machine that achieves self-righting flight using flapping wings alone, without relying on additional aerodynamic surfaces and without feedback control. We design, construct, and test-fly a prototype that opens and closes four wings, resembling the motions of swimming jellyfish more so than any insect or bird. Lift measurements and high-speed video of free-flight are used to inform an aerodynamic model that explains the stabilization mechanism. These results show the promise of flapping-flight strategies beyond those that directly mimic the wing motions of flying animals.

[Lipid variation in oocytes of the jellyfish Stomolophus meleagris (Scyphozoa: Rhizostomeae) from Las Guasimas Lagoon, Mexico, during gonadal development].

PubMed

Carvalho-Saucedo, Liliana; García-Domínguez, Federico; Rodríguez-Jaramillo, Carmen; López-Martínez, Juana

2010-03-01

The jellyfish Stomolophus meleagris has potential for commercial exploitation but there is little information on their reproductive biology. This paper seeks to evaluate some biochemical and demographic characteristics of the species. Samples were taken monthly during 2005 and 2006. Jellyfish collected in 2005 were used to describe the characteristics and quantity of oocyte triglycerides and phospholipids with the Sudan black technique, and to ascertain the degree of gonadal development and sex ratio by the hematoxylin-eosin technique. The 2006 jellyfish were used to determine the size at first maturity and protein and total lipids contents. Four stages of development in both sexes were determined, with a continuous gamete development. The highest percentage of mature organisms was recorded in April. The proportion of sexes was 0.7:1.3. We found higher concentrations of triglycerides than phospholipids in the cytoplasm. There was a positive correlation between triglycerides and the diameter of the oocyte. The size at first maturity for both sexes was 105 mm. The highest protein and lipids contents were obtained in April and March respectively.

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…

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.

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.

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.

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.

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. Copyright © 2013 Elsevier Ltd. All rights reserved.

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.

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.

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

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

Electromyography of the buccal musculature of octopus (Octopus bimaculoides): a test of the function of the muscle articulation in support and movement.

PubMed

Uyeno, Theodore A; Kier, William M

2007-01-01

The buccal mass musculature of the octopus (Octopus bimaculoides) was studied with electromyography to test the predictions of a previous morphological study in which we suggested that the muscles of the buccal mass serve as both the effectors of movement and as the joint itself, forming a new category of flexible joint termed a ;muscle articulation'. The predictions of muscle function were tested by correlating muscle electrical activity in isolated buccal masses with spontaneous beak movements. Bipolar electromyography electrodes were implanted in the various beak muscles and beak position was recorded simultaneously with an electronic movement monitor (N=14). The results are consistent with the hypothesis that the lateral mandibular muscles produce opening movements of the beaks and provide the first definitive explanation of the opening mechanism. The results are also consistent with the hypothesis that the superior mandibular muscle functions primarily in closing. Co-contraction of the lateral mandibular muscles and the superior mandibular muscles was also observed, suggesting that these muscles may also stabilize the beaks during movement or provide a means of controlling the location of the pivot between the beaks. This study provides an important first test of the predictions of the role of the complex musculature found in muscle articulations such as the cephalopod buccal mass.

Biology and ecology of Irukandji jellyfish (Cnidaria: Cubozoa).

PubMed

Gershwin, Lisa-ann; Richardson, Anthony J; Winkel, Kenneth D; Fenner, Peter J; Lippmann, John; Hore, Russell; Avila-Soria, Griselda; Brewer, David; Kloser, Rudy J; Steven, Andy; Condie, Scott

2013-01-01

Irukandji stings are a leading occupational health and safety issue for marine industries in tropical Australia and an emerging problem elsewhere in the Indo-Pacific and Caribbean. Their mild initial sting frequently results in debilitating illness, involving signs of sympathetic excess including excruciating pain, sweating, nausea and vomiting, hypertension and a feeling of impending doom; some cases also experience acute heart failure and pulmonary oedema. These jellyfish are typically small and nearly invisible, and their infestations are generally mysterious, making them scary to the general public, irresistible to the media, and disastrous for tourism. Research into these fascinating species has been largely driven by the medical profession and focused on treatment. Biological and ecological information is surprisingly sparse, and is scattered through grey literature or buried in dispersed publications, hampering understanding. Given that long-term climate forecasts tend toward conditions favourable to jellyfish ecology, that long-term legal forecasts tend toward increasing duty-of-care obligations, and that bioprospecting opportunities exist in the powerful Irukandji toxins, there is a clear need for information to help inform global research and robust management solutions. We synthesise and contextualise available information on Irukandji taxonomy, phylogeny, reproduction, vision, behaviour, feeding, distribution, seasonality, toxins, and safety. Despite Australia dominating the research in this area, there are probably well over 25 species worldwide that cause the syndrome and it is an understudied problem in the developing world. Major gaps in knowledge are identified for future research: our lack of clarity on the socio-economic impacts, and our need for time series and spatial surveys of the species, make this field particularly enticing. © 2013 Elsevier Ltd. All rights reserved.

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.

'Literacy Octopus' Dissemination Trial: Evaluation Report and Executive Summary

ERIC Educational Resources Information Center

Lord, Pippa; Rabiasz, Adam; Styles, Ben

2017-01-01

The "'Literacy Octopus' Dissemination Trial" aimed to test the impact on pupil outcomes of disseminating research summaries and evidence-based resources to schools. The materials aimed to support teaching and learning of Key Stage 2 literacy and were created by leading organisations with experience of engaging schools in evidence use.…

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

2017-03-01

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. Copyright © 2017 Elsevier Inc. All rights reserved.

Development studies of Aurelia (jellyfish) ephyrae which developed during the SLS-1 mission

NASA Technical Reports Server (NTRS)

Spangenberg, D. B.; Jernigan, T.; Mccombs, R.; Lowe, B. T.; Sampson, M.; Slusser, J.

1994-01-01

Aurelia polyps (scyphistomae) and ephyrae were exposed to microgravity for nine days aboard the space shuttle during the SLS-1 mission. During strobilation, polyps segment transversely and each segment develops into an ephyra. Polyps were induced to strobilate at 28 C, using iodine or thyroxine, at L(Launch)-48h, L-24h, and L+8h. Ephyrae developed in the groups tested in space and on Earth. The number of ephyrae formed per polyp was slightly higher in the L+8h groups as compared with those induced at L-24h and L-48h. On Earth, iodine is used by jellyfish to synthesize jellyfish-thyroxine (Jf T(sub 4)), needed for ephyra production. Since iodine-treated polyps strobilated and formed ephyrae in space, it appears that jellyfish can synthesize Jf-T(sub 4) in space. Indeed, two groups of polyps not given inducer formed ephryae in space, presumably due to enhanced Jf-T(sub 4) synthesis, utilization or accumulation. Some ephyrae that formed in space were also fixed in space on Mission Day (MD) 8; others were fixed post-flight. Examination of living ephyrae with the light microscope and fixed ones with the Scanning and Transmission Electron Microscopes revealed that those which developed in space were morphologically very similar to those which developed on Earth. Quantitation of arm numbers determined that there were no significant differences between space and Earth-developed ephyrae. Pulsing abnormalities, however, were found in greater number (18.3%) in space-developed ephyrae than in Earth-developed controls (2.9%). These abnormalities suggest abnormal development of the graviceptors, the neuromuscular system, or a defect in the integration between these systems in apparently microgravity-sensitive animals.

Changes in bacterial community metabolism and composition during the degradation of dissolved organic matter from the jellyfish Aurelia aurita in a Mediterranean coastal lagoon.

PubMed

Blanchet, Marine; Pringault, Olivier; Bouvy, Marc; Catala, Philippe; Oriol, Louise; Caparros, Jocelyne; Ortega-Retuerta, Eva; Intertaglia, Laurent; West, Nyree; Agis, Martin; Got, Patrice; Joux, Fabien

2015-09-01

Spatial increases and temporal shifts in outbreaks of gelatinous plankton have been observed over the past several decades in many estuarine and coastal ecosystems. The effects of these blooms on marine ecosystem functioning and particularly on the dynamics of the heterotrophic bacteria are still unclear. The response of the bacterial community from a Mediterranean coastal lagoon to the addition of dissolved organic matter (DOM) from the jellyfish Aurelia aurita, corresponding to an enrichment of dissolved organic carbon (DOC) by 1.4, was assessed for 22 days in microcosms (8 l). The high bioavailability of this material led to (i) a rapid mineralization of the DOC and dissolved organic nitrogen from the jellyfish and (ii) the accumulation of high concentrations of ammonium and orthophosphate in the water column. DOM from jellyfish greatly stimulated heterotrophic prokaryotic production and respiration rates during the first 2 days; then, these activities showed a continuous decay until reaching those measured in the control microcosms (lagoon water only) at the end of the experiment. Bacterial growth efficiency remained below 20%, indicating that most of the DOM was respired and a minor part was channeled to biomass production. Changes in bacterial diversity were assessed by tag pyrosequencing of partial bacterial 16S rRNA genes, DNA fingerprints, and a cultivation approach. While bacterial diversity in control microcosms showed little changes during the experiment, the addition of DOM from the jellyfish induced a rapid growth of Pseudoalteromonas and Vibrio species that were isolated. After 9 days, the bacterial community was dominated by Bacteroidetes, which appeared more adapted to metabolize high-molecular-weight DOM. At the end of the experiment, the bacterial community shifted toward a higher proportion of Alphaproteobacteria. Resilience of the bacterial community after the addition of DOM from the jellyfish was higher for metabolic functions than diversity

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.

First complete mitochondrial genome sequence from a box jellyfish reveals a highly fragmented linear architecture and insights into telomere evolution.

PubMed

Smith, David Roy; Kayal, Ehsan; Yanagihara, Angel A; Collins, Allen G; Pirro, Stacy; Keeling, Patrick J

2012-01-01

Animal mitochondrial DNAs (mtDNAs) are typically single circular chromosomes, with the exception of those from medusozoan cnidarians (jellyfish and hydroids), which are linear and sometimes fragmented. Most medusozoans have linear monomeric or linear bipartite mitochondrial genomes, but preliminary data have suggested that box jellyfish (cubozoans) have mtDNAs that consist of many linear chromosomes. Here, we present the complete mtDNA sequence from the winged box jellyfish Alatina moseri (the first from a cubozoan). This genome contains unprecedented levels of fragmentation: 18 unique genes distributed over eight 2.9- to 4.6-kb linear chromosomes. The telomeres are identical within and between chromosomes, and recombination between subtelomeric sequences has led to many genes initiating or terminating with sequences from other genes (the most extreme case being 150 nt of a ribosomal RNA containing the 5' end of nad2), providing evidence for a gene conversion-based model of telomere evolution. The silent-site nucleotide variation within the A. moseri mtDNA is among the highest observed from a eukaryotic genome and may be associated with elevated rates of recombination.

Investigation into the hemolytic activity of tentacle venom from jellyfish Cyanea nozakii Kishinouye

NASA Astrophysics Data System (ADS)

Li, Cuiping; Yu, Huahua; Li, Rongfeng; Xing, Ronge; Liu, Song; Li, Pengcheng

2016-03-01

Cyanea nozakii Kishinouy e ( C. nozakii), a giant cnidarian of the class Scyphomedusae, order Semaeostomeae and family Cyaneidae, is widely distributed in the East China Sea, the Yellow Sea and the Bohai Sea, and is abundant from late summer to early autumn. Venom produced by C. nozakii during mass agglomerations can contaminate seawater resulting in death of the halobios and seriously damage commercial fisheries. Swimmers and fishermen commonly suff er painful stings from this jellyfish, resulting in local edema, tingling, breathing difficulties, depressed blood pressure and even death. Such effects arise from the complex mixture of biologically active molecules that make up jellyfish venom. In the present study, the hemolytic activity of venom from tentacles of C. nozakii and factors aff ecting its activity were assayed. The HU50 ( defined as the amount of protein required to lyse 50 % of erythrocytes) of the venom against dove and chicken erythrocytes was 34 and 59 μg/mL, respectively. Carboxylmethyl chitosan and glycerol could increase hemolytic activity at concentrations greater than 0.06% and 0.2 mol/L, respectively.

Characterisation of acid-soluble and pepsin-solubilised collagen from jellyfish (Cyanea nozakii Kishinouye).

PubMed

Zhang, Junjie; Duan, Rui; Huang, Lei; Song, Yujie; Regenstein, Joe M

2014-05-01

Annual outbreaks of the Jellyfish (Cyanea nozakii Kishinouye) in the waters of the Yellow Sea and the East China Sea are regarded as a nuisance. Thus, utilizing this jellyfish species is of great significance to reduce harm to fisheries and marine environments. The yield of the acid-soluble collagens (ASCs) from the C. nozakii umbrella was 13.0% (dry weight) and that of the pepsin-solubilised collagens (PSCs) was 5.5% (dry weight). The SDS-PAGE patterns of the ASCs and PSCs differed from that of type I collagen, which indicate the presence of (α1)3. The denaturation temperature (Td) of the collagens was approximately 23.8°C. Fourier transform infrared spectroscopy proved that the ASCs and PSCs retained their helical structures and the As, Pb, and Hg content of the collagens, detected by ICP-MS, were considerably lower than the national standards. The results suggest that collagens isolated from C. nozakii can potentially be used as an alternative source of collagen for use in various applications. Copyright © 2013 Elsevier Ltd. All rights reserved.

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. Copyright © 2013 Elsevier Inc. All rights reserved.

Intervention effects of five cations and their correction on hemolytic activity of tentacle extract from the jellyfish Cyanea capillata

PubMed Central

2017-01-01

Cations have generally been reported to prevent jellyfish venom-induced hemolysis through multiple mechanisms by spectrophotometry. Little attention has been paid to the potential interaction between cations and hemoglobin, potentially influencing the antagonistic effect of cations. Here, we explored the effects of five reported cations, La3+, Mn2+, Zn2+, Cu2+ and Fe2+, on a hemolytic test system and the absorbance of hemoglobin, which was further used to measure their effects on the hemolysis of tentacle extract (TE) from the jellyfish Cyanea capillata. All the cations displayed significant dose-dependent inhibitory effects on TE-induced hemolysis with various dissociation equilibrium constant (Kd) values as follows: La3+ 1.5 mM, Mn2+ 93.2 mM, Zn2+ 38.6 mM, Cu2+ 71.9 μM and Fe2+ 32.8 mM. The transparent non-selective pore blocker La3+ did not affect the absorbance of hemoglobin, while Mn2+ reduced it slightly. Other cations, including Zn2+, Cu2+ and Fe2+, greatly decreased the absorbance with Kd values of 35.9, 77.5 and 17.6 mM, respectively. After correction, the inhibitory Kd values were 1.4 mM, 45.8 mM, 128.5 μM and 53.1 mM for La3+, Zn2+, Cu2+ and Fe2+, respectively. Mn2+ did not inhibit TE-induced hemolysis. Moreover, the inhibitory extent at the maximal given dose of all cations except La3+ was also diminished. These corrected results from spectrophotometry were further confirmed by direct erythrocyte counting under microscopy. Our results indicate that the cations, except for La3+, can interfere with the absorbance of hemoglobin, which should be corrected when their inhibitory effects on hemolysis by jellyfish venoms are examined. The variation in the inhibitory effects of cations suggests that the hemolysis by jellyfish venom is mainly attributed to the formation of non-selective cation pore complexes over other potential mechanisms, such as phospholipases A2 (PLA2), polypeptides, protease and oxidation. Blocking the pore-forming complexes may be a

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. Copyright © 2012. Published by Elsevier SAS.

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.

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

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.

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.

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.

Jellyfish support high energy intake of leatherback sea turtles (Dermochelys coriacea): video evidence from animal-borne cameras.

PubMed

Heaslip, Susan G; Iverson, Sara J; Bowen, W Don; James, Michael C

2012-01-01

The endangered leatherback turtle is a large, highly migratory marine predator that inexplicably relies upon a diet of low-energy gelatinous zooplankton. The location of these prey may be predictable at large oceanographic scales, given that leatherback turtles perform long distance migrations (1000s of km) from nesting beaches to high latitude foraging grounds. However, little is known about the profitability of this migration and foraging strategy. We used GPS location data and video from animal-borne cameras to examine how prey characteristics (i.e., prey size, prey type, prey encounter rate) correlate with the daytime foraging behavior of leatherbacks (n = 19) in shelf waters off Cape Breton Island, NS, Canada, during August and September. Video was recorded continuously, averaged 1:53 h per turtle (range 0:08-3:38 h), and documented a total of 601 prey captures. Lion's mane jellyfish (Cyanea capillata) was the dominant prey (83-100%), but moon jellyfish (Aurelia aurita) were also consumed. Turtles approached and attacked most jellyfish within the camera's field of view and appeared to consume prey completely. There was no significant relationship between encounter rate and dive duration (p = 0.74, linear mixed-effects models). Handling time increased with prey size regardless of prey species (p = 0.0001). Estimates of energy intake averaged 66,018 kJ • d(-1) but were as high as 167,797 kJ • d(-1) corresponding to turtles consuming an average of 330 kg wet mass • d(-1) (up to 840 kg • d(-1)) or approximately 261 (up to 664) jellyfish • d(-1). Assuming our turtles averaged 455 kg body mass, they consumed an average of 73% of their body mass • d(-1) equating to an average energy intake of 3-7 times their daily metabolic requirements, depending on estimates used. This study provides evidence that feeding tactics used by leatherbacks in Atlantic Canadian waters are highly profitable and our results are consistent with estimates of mass gain prior to

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. Copyright © 2012 Elsevier Ltd. All rights reserved.

User's manual for a material transport code on the Octopus Computer Network

DOE Office of Scientific and Technical Information (OSTI.GOV)

Naymik, T.G.; Mendez, G.D.

1978-09-15

A code to simulate material transport through porous media was developed at Oak Ridge National Laboratory. This code has been modified and adapted for use at Lawrence Livermore Laboratory. This manual, in conjunction with report ORNL-4928, explains the input, output, and execution of the code on the Octopus Computer Network.

Structural and Developmental Disparity in the Tentacles of the Moon Jellyfish Aurelia sp.1

PubMed Central

Gold, David A.; Nakanishi, Nagayasu; Hensley, Nicholai M.; Cozzolino, Kira; Tabatabaee, Mariam; Martin, Michelle; Hartenstein, Volker; Jacobs, David K.

2015-01-01

Tentacles armed with stinging cells (cnidocytes) are a defining trait of the cnidarians, a phylum that includes sea anemones, corals, jellyfish, and hydras. While cnidarian tentacles are generally characterized as structures evolved for feeding and defense, significant variation exists between the tentacles of different species, and within the same species across different life stages and/or body regions. Such diversity suggests cryptic distinctions exist in tentacle function. In this paper, we use confocal and transmission electron microscopy to contrast the structure and development of tentacles in the moon jellyfish, Aurelia species 1. We show that polyp oral tentacles and medusa marginal tentacles display markedly different cellular and muscular architecture, as well as distinct patterns of cellular proliferation during growth. Many structural differences between these tentacle types may reflect biomechanical solutions to different feeding strategies, although further work would be required for a precise mechanistic understanding. However, differences in cell proliferation dynamics suggests that the two tentacle forms lack a conserved mechanism of development, challenging the textbook-notion that cnidarian tentacles can be homologized into a conserved bauplan. PMID:26241309

Structural and Developmental Disparity in the Tentacles of the Moon Jellyfish Aurelia sp.1.

PubMed

Gold, David A; Nakanishi, Nagayasu; Hensley, Nicholai M; Cozzolino, Kira; Tabatabaee, Mariam; Martin, Michelle; Hartenstein, Volker; Jacobs, David K

2015-01-01

Tentacles armed with stinging cells (cnidocytes) are a defining trait of the cnidarians, a phylum that includes sea anemones, corals, jellyfish, and hydras. While cnidarian tentacles are generally characterized as structures evolved for feeding and defense, significant variation exists between the tentacles of different species, and within the same species across different life stages and/or body regions. Such diversity suggests cryptic distinctions exist in tentacle function. In this paper, we use confocal and transmission electron microscopy to contrast the structure and development of tentacles in the moon jellyfish, Aurelia species 1. We show that polyp oral tentacles and medusa marginal tentacles display markedly different cellular and muscular architecture, as well as distinct patterns of cellular proliferation during growth. Many structural differences between these tentacle types may reflect biomechanical solutions to different feeding strategies, although further work would be required for a precise mechanistic understanding. However, differences in cell proliferation dynamics suggests that the two tentacle forms lack a conserved mechanism of development, challenging the textbook-notion that cnidarian tentacles can be homologized into a conserved bauplan.

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.

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.

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

2017-12-01

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.

Firing the Sting: Chemically Induced Discharge of Cnidae Reveals Novel Proteins and Peptides from Box Jellyfish (Chironex fleckeri) Venom

PubMed Central

Jouiaei, Mahdokht; Casewell, Nicholas R.; Yanagihara, Angel A.; Nouwens, Amanda; Cribb, Bronwen W.; Whitehead, Darryl; Jackson, Timothy N. W.; Ali, Syed A.; Wagstaff, Simon C.; Koludarov, Ivan; Alewood, Paul; Hansen, Jay; Fry, Bryan G.

2015-01-01

Cnidarian venom research has lagged behind other toxinological fields due to technical difficulties in recovery of the complex venom from the microscopic nematocysts. Here we report a newly developed rapid, repeatable and cost effective technique of venom preparation, using ethanol to induce nematocyst discharge and to recover venom contents in one step. Our model species was the Australian box jellyfish (Chironex fleckeri), which has a notable impact on public health. By utilizing scanning electron microscopy and light microscopy, we examined nematocyst external morphology before and after ethanol treatment and verified nematocyst discharge. Further, to investigate nematocyst content or “venom” recovery, we utilized both top-down and bottom-up transcriptomics–proteomics approaches and compared the proteome profile of this new ethanol recovery based method to a previously reported high activity and recovery protocol, based upon density purified intact cnidae and pressure induced disruption. In addition to recovering previously characterized box jellyfish toxins, including CfTX-A/B and CfTX-1, we recovered putative metalloproteases and novel expression of a small serine protease inhibitor. This study not only reveals a much more complex toxin profile of Australian box jellyfish venom but also suggests that ethanol extraction method could augment future cnidarian venom proteomics research efforts. PMID:25793725

Heat shock protein 70 and heat shock protein 90 expression in light- and dark-adapted adult octopus retinas.

PubMed

Ochoa, Gina H; Clark, Ying Mei; Matsumoto, Brian; Torres-Ruiz, Jose A; Robles, Laura J

2002-02-01

Light- and dark-adaptation leads to changes in rhabdom morphology and photopigment distribution in the octopus retina. Molecular chaperones, including heat shock proteins (Hsps), may be involved in specific signaling pathways that cause changes in photoreceptor actin- and tubulin-based cytoskeletons and movement of the photopigments, rhodopsin and retinochrome. In this study, we used immunoblotting, in situ RT-PCR, immunofluorescence and confocal microscopy to localize the inducible form of Hsp70 and the larger Hsp90 in light- and dark-adapted and dorsal and ventral halves of adult octopus retinas. The Hsps showed differences in distribution between the light and dark and in dorsal vs. ventral position in the retina. Double labeling confocal microscopy co-localized Hsp70 with actin and tubulin, and Hsp90 with the photopigment, retinochrome. Our results demonstrate the presence of Hsp70 and Hsp90 in otherwise non-stressed light- and dark-adapted octopus retinas. These Hsps may help stabilize the cytoskeleton, important for rhabdom structure, and are perhaps involved in the redistribution of retinochrome in conditions of light and dark.

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. Copyright © 2012 Elsevier Ltd. All rights reserved.

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. Copyright © 2015 Elsevier Ltd. All rights reserved.

Jellyfish: Observational Properties of Extreme Ram-Pressure Stripping Events in Massive Galaxy Clusters

NASA Astrophysics Data System (ADS)

Conor, McPartland; Ebeling, Harald; Roediger, Elke

2015-08-01

We investigate the physical origin and observational signatures of extreme ram-pressure stripping (RPS) in 63 massive galaxy clusters at z=0.3-0.7, based on data in the F606W passband obtained with the Advanced Camera for Surveys aboard the Hubble Space Telescope. Using a training set of a dozen ``jellyfish" galaxies identified earlier in the same imaging data, we define quantitative morphological criteria to select candidate galaxies which are similar to known cases of RPS. Considering a sample of 16 ``jellyfish" galaxies (10 of which we present for the first time), we visually derive estimates of the projected direction of motion based on dynamical features such as apparent compression shocks and debris trails. Our findings suggest that the observed events occur primarily at large distances from the cluster core and involve infall trajectories featuring high impact parameters. Simple models of cluster growth show that such trajectories are consistent with two scenarios: 1) galaxy infall along filaments; and 2) infall at high velocities (≥1000 km/s) characteristic of cluster mergers. The observed distribution of events is best described by timescales of ˜few Myr in agreement with recent numerical simulations of RPS. The broader areal coverage of the Hubble Frontier Fields should provide an even larger sample of RPS events to determine the relative contributions of infall and cluster mergers. Prompted by the discovery of several jellyfish galaxies whose brightness in the F606W passband rivals or exceeds that of the respective brightest cluster galaxy, we attempt to constrain the luminosity function of galaxies undergoing RPS. The observed significant excess at the bright end compared to the luminosity functions of blue cluster members strongly suggests enhanced star formation, thus challenging theoretical and numerical studies according to which RPS merely displaces existing star-forming regions. In-depth studies of individual objects will help test our

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.

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. Copyright © 2013 Elsevier Inc. All rights reserved.

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.

Primary processes in photolysis of octopus rhodopsin.

PubMed

Ohtani, H; Kobayashi, T; Tsuda, M; Ebrey, T G

1988-01-01

The photolysis of octopus rhodopsin was studied by picosecond time-resolved spectroscopy at physiological temperature (8 degrees 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 D(2)O takes place more slowly than in H(2)O. This indicates that the lifetime of primerhodopsin is decreased by H(2)O/D(2)O 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.

Evidence-Based Literacy Support: The "Literacy Octopus" Trial. Evaluation Report and Executive Summary

ERIC Educational Resources Information Center

Lord, Pippa; Rabiasz, Adam; Roy, Palak; Harland, Jennie; Styles, Ben; Fowler, Katherine

2017-01-01

The Evidence-based Literacy Support-"Literacy Octopus" Trial tested a range of dissemination interventions and resources, all of which aimed to engage schools in using evidence-based materials to improve teaching and learning in Key Stage 2 literacy. Four delivery partners provided interventions. These included light-touch,…

Molecular characterization of aspartylglucosaminidase, a lysosomal hydrolase upregulated during strobilation in the moon jellyfish, Aurelia aurita.

PubMed

Tsujita, Natsumi; Kuwahara, Hiroyuki; Koyama, Hiroki; Yanaka, Noriyuki; Arakawa, Kenji; Kuniyoshi, Hisato

2017-05-01

The life cycle of the moon jellyfish, Aurelia aurita, alternates between a benthic asexual polyp stage and a planktonic sexual medusa (jellyfish) stage. Transition from polyp to medusa is called strobilation. To investigate the molecular mechanisms of strobilation, we screened for genes that are upregulated during strobilation using the differential display method and we identified aspartylglucosaminidase (AGA), which encodes a lysosomal hydrolase. Similar to AGAs from other species, Aurelia AGA possessed an N-terminal signal peptide and potential N-glycosylation sites. The genomic region of Aurelia AGA was approximately 9.8 kb in length and contained 12 exons and 11 introns. Quantitative RT-PCR analysis revealed that AGA expression increased during strobilation, and was then decreased in medusae. To inhibit AGA function, we administered the lysosomal acidification inhibitors, chloroquine or bafilomycin A1, to animals during strobilation. Both inhibitors disturbed medusa morphogenesis at the oral end, suggesting involvement of lysosomal hydrolases in strobilation.

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.

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

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

Role of Thyroxine in Space-Developed Jellyfish

NASA Technical Reports Server (NTRS)

Spangenberg, Dorothy B.

1997-01-01

The Aurelia Metamorphosis Test System was previously used to determine the effects of the space environment on the development and behavior of tiny (1-2 mm) jellyfish ephyrae during the SLS-1 and IML-2 missions. Results from the SLS-1 experiment included the discovery that statolith numbers were significantly reduced in Earth-formed ephyrae flown for nine days in space as compared with ground-based controls. In addition, upon return to Earth, six times more ephyrae which had developed in space than those developed on Earth had pulsing abnormalities, indicating that either these animals did not form their neuromuscular structures normally while in space or they were unable to adapt to the Ig environment upon return to Earth. The metamorphosis process, which enables the formation of ephyrae from polyps is influenced by a hormone, Jf-T4 Oellyfish thyroxine) which is synthesized following iodine administration. Two groups of polyps in space, however, formed ephyrae without iodine administration indicating that Jf-T4 synthesis, utilization, or excretion was different in. the ephyrae. Increased synthesis or build-up in the media of the hormone may also be linked to the increased demineralization of statoliths found in space-exposed ephyrae. In previous experiments, we found that externally administered thyroxine causes increased demineralization of statoliths on Earth. Abnormal pulsina in ephyrae following return to Earth during the SLS-1 mission may also be traced to increased Jf-T4 levels. Thyroxine is known to be important to the normal development and function of the nervous system, heart, and skeletal muscles in higher animals. For this third Jellyfish-in-Space experiment, we proposed to quantitate the levels of Jf- T4 and of T4 receptors in space-developed ephyrae and media and to compare these levels with those of animals developing and at Ig in space and on Earth. We expected to be able to determine whether Jf-T4 synthesis and/or secretion is different in space

In depth analysis of the in vivo toxicity of venom from the jellyfish Stomolophus meleagris.

PubMed

Li, Rongfeng; Yu, Huahua; Yue, Yang; Liu, Song; Xing, Ronge; Chen, Xiaolin; Wang, Xueqin; Li, Pengcheng

2014-12-15

Jellyfish Stomolophus meleagris, a synonym of Nemopilema nomurai, which has often bloomed in the China Sea in recent years, is becoming an increasing threat to human health and life as a result of its strong toxicity. Each year, hundreds of thousands of people were stung, especially in the high season, and the victims suffered itch, edema, myalgia, dyspnea, hypotension, shock and even death. Here, we present the in-depth analysis of the in vivo toxicity of the venom from the jellyfish S. meleagris by using both an acute toxicological approach and pathological analyses. The venom showed an LD50 of approximately 2.92 μg/g body weight in mice following an intravenous injection and caused renal glomerular swelling, renal vesicle stricture, renal tubules dilatation, hepatic blood sinusoid dilatation, pulmonary edema and malignant pleural effusion. The pathological sections analysis showed that the kidney and liver were significantly damaged, but the heart, spleen and stomach had no observed changes. Additionally, the hemanalysis showed an increase of white blood cells (WBC), middle cells (Mid), alanine aminotransferase (ALT), blood urine nitrogen (BUN) and uric acid (UA) in the blood. Moreover, the mice also displayed convulsions, mouth bleeding, piloerection, dyspnea and death after the injection of the venom. In conclusion, this venom has a strong toxicity to the kidney of the mice and the acute renal failure might be one of the most important factors for the death after a severe sting. Hopefully, the present study will provide a significant reference for the treatment of stings by the jellyfish S. meleagris in the future. Copyright © 2014 Elsevier Ltd. All rights reserved.

Impact assessment of non-indigenous jellyfish species on the estuarine community dynamic: A model of medusa phase

NASA Astrophysics Data System (ADS)

Muha, Teja Petra; Teodósio, Maria Alexandra; Ben-Hamadou, Radhouan

2017-03-01

Non-indigenous jellyfish species (NIJS) Blackforida virginica have recently been introduced to the Guadiana Estuary. A modelling approach was used for the assessment of the species-specific impact on the native community, during the medusa phase. The novel interactions between NIJS and the native community are assessed through biomass variation including hydrodynamic and climatic variables. Sensitivity analysis shows that both native species, as well as NIJS highly depend on the water discharge regime, nutrient contribution and the amount of detritus production. Abiotic factors such as the Northern Atlantic Oscillation, water discharge, nutrient load and detritus production are the most influential factors for the dynamics of the estuarine ecosystem demonstrated by the model. Low water discharge and low nutrient retention rate appear to be the most favourable conditions for B. virginica. The species is a non-selective predator able to integrate into the system effectively and has caused a decrease in the biomass of other organisms in the estuarine ecosystem throughout the summer after dam removal. The B. virginica significant impact can be evaluated only when the jellyfish detritus food pathway is involved. The B. virginica predatory impact potential, as well as food preference, appears to be the most influential factors for the overall biomass variation. On the contrary, winter freshwater pulses reduce the survival rate of jellyfish polyps which results in a decrease of medusa during summer. The model presents a strong ecohydrology movement where the fluctuation of organism biomass strongly depends on the hydrological conditions including the amount of nutrient load.

Livermore time-sharing system. Part I. Octopus. Chapter 3. Teletypewriters. [Manual for teletypewriter use

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fletcher, J.G.; Richards, M.D.; Du Bois, P.

1977-04-15

Most of the interactive terminals in the Octopus system are teletypewriters. The behavior of each teletypewriter is closely associated with the operation of the PDP-8 concentrator to which it is attached. This report contains all information necessary for proper use of the teletypewriter. (RWR)

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.

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.

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.

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

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.

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.

Complete mitochondrial genome of the jellyfish, Chrysaora quinquecirrha (Cnidaria, Scyphozoa).

PubMed

Hwang, Dae-Sik; Park, Eunji; Won, Yong-Jin; Lee, Woo-Jin; Shin, Kyoungsoon; Lee, Jae-Seong

2014-02-01

We sequenced 16,775 bp of the linear mitochondrial DNA of the jellyfish Chrysaora quinquecirrha and characterized them. C. quinquecirrha has 13 protein-coding genes (PCGs), 16S rRNA and 12S rRNA with 3 tRNAs (tRNA-Leu, tRNA-Ser(TGA), tRNA-Met) as shown in Aurelia sp. nov. Both have another two PCGs such as helicase and orf363 with telomeres at both ends. The PCGs of C. quinquecirrha shows anti-G bias on 2nd and 3rd positions of PCGs as well as anti-C bias on 1st and 3rd positions of PCGs.

Prospective study of Chironex fleckeri and other box jellyfish stings in the "Top End" of Australia's Northern Territory.

PubMed

Currie, Bart J; Jacups, Susan P

To describe the epidemiology and clinical features of box jellyfish envenoming in the Top End of the Northern Territory and, in particular, confirmed stings from the major Australian box jellyfish, Chironex fleckeri. Prospective collection of clinical data and skin scrapings or sticky-tape tests for nematocyst identification from patients presenting to Royal Darwin Hospital and remote coastal community health clinics in the Northern Territory, spanning 10 950 km of coastline; analysis of tidal, weather and seasonal data. All patients with jellyfish sting details recorded between 1 April 1991 and 30 May 2004. Demographic and clinical features, use of C. fleckeri antivenom, and associations between weather, seasonal and tidal factors and confirmed C. fleckeri stings. Of 606 jellyfish stings documented, 225 were confirmed to have been caused by C. fleckeri. 37% of C. fleckeri stings were in children, 92% occurred during the "stinger season" (1 October to 1 June), 83% occurred in water 1 m or less deep, and 17% occurred while victims were entering the water. Stings were least common on outgoing tides (P < 0.001) and commonest between 15:00 and 18:00 (P < 0.001) and on days with wind speed less than that month's average (P < 0.001). Nearly all victims experienced immediate pain, but this could often be controlled with ice; only 30% required parenteral narcotics and 8% required hospital admission. Cardiorespiratory arrest occurred within several minutes of the sting in the one fatal case, involving a 3-year-old girl with only 1.2 m of visible tentacle contact. C. fleckeri antivenom was given to another 21 patients, none of whom had life-threatening features at the time they were given antivenom. Most C. fleckeri stings are not life-threatening; patients who die usually have cardiopulmonary arrest within minutes of the sting. The potential benefit of antivenom and magnesium under these circumstances remains to be shown, but a protocol with their rapid use is recommended

Ecosystem relevance of variable jellyfish biomass in the Irish Sea between years, regions and water types

NASA Astrophysics Data System (ADS)

Bastian, Thomas; Lilley, Martin K. S.; Beggs, Steven E.; Hays, Graeme C.; Doyle, Thomas K.

2014-08-01

Monitoring the abundance and distribution of taxa is essential to assess their contribution to ecosystem processes. For marine taxa that are difficult to study or have long been perceived of little ecological importance, quantitative information is often lacking. This is the case for jellyfish (medusae and other gelatinous plankton). In the present work, 4 years of scyphomedusae by-catch data from the 2007-2010 Irish Sea juvenile gadoid fish survey were analysed with three main objectives: (1) to provide quantitative and spatially-explicit species-specific biomass data, for a region known to have an increasing trend in jellyfish abundance; (2) to investigate whether year-to-year changes in catch-biomass are due to changes in the numbers or in the size of medusa (assessed as the mean mass per individual), and (3) to determine whether inter-annual variation patterns are consistent between species and water masses. Scyphomedusae were present in 97% of samples (N = 306). Their overall annual median catch-biomass ranged from 0.19 to 0.92 g m-3 (or 8.6 to 42.4 g m-2). Aurelia aurita and Cyanea spp. (Cyanea lamarckii and Cyanea capillata) made up 77.7% and 21.5% of the total catch-biomass respectively, but species contributions varied greatly between sub-regions and years. No consistent pattern was detected between the distribution and inter-annual variations of the two genera, and contrasting inter-annual patterns emerged when considering abundance either as biomass or as density. Significantly, A. aurita medusae were heavier in stratified than in mixed waters, which we hypothesize may be linked to differences in timing and yield of primary and secondary productions between water masses. These results show the vulnerability of time-series from bycatch datasets to phenological changes and highlight the importance of taking species- and population-specific distribution patterns into account when integrating jellyfish into ecosystem models.

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.

Jellyfish collagen and alginate: Combined marine materials for superior chondrogenesis of hMSC.

PubMed

Pustlauk, W; Paul, B; Gelinsky, M; Bernhardt, A

2016-07-01

Marine, hybrid constructs of porous scaffolds from fibrillized jellyfish collagen and alginate hydrogel are mimicking both of the main tissue components of cartilage, thus being a promising approach for chondrogenic differentiation of human mesenchymal stem cells (hMSC). Investigating their potential for articular cartilage repair, the present study examined scaffolds being either infiltrated with an alginate-cell-suspension (ACS) or seeded with hMSC and embedded in alginate after cell adhesion (EAS). Hybrid constructs with 2×10(5) and 4.5×10(5)hMSC/scaffold were compared to hMSC encapsulated in pure alginate discs, both chondrogenically stimulated for 21days. Typical round, chondrocyte-like morphology was observed in pure alginate gels and ACS scaffolds, while cells in EAS were elongated and tightly attached to the collagen pores. Col 2 gene expression was comparable in all scaffold types examined. However, the Col 2/Col 1 ratio was higher for pure alginate discs and ACS scaffolds compared to EAS. In contrast, cells in EAS scaffolds displayed higher gene expression of Sox 9, Col 11 and ACAN compared to ACS and pure alginate. Secretion of sulfated glycosaminoglycans (sGAG) was comparable for ACS and EAS scaffolds. In conclusion hybrid constructs of jellyfish collagen and alginate support hMSC chondrogenic differentiation and provide more stable and constructs compared to pure hydrogels. Copyright © 2016 Elsevier B.V. All rights reserved.

Lipid Profile in Different Parts of Edible Jellyfish Rhopilema esculentum.

PubMed

Zhu, Si; Ye, Mengwei; Xu, Jilin; Guo, Chunyang; Zheng, Huakun; Hu, Jiabao; Chen, Juanjuan; Wang, Yajun; Xu, Shanliang; Yan, Xiaojun

2015-09-23

Jellyfish Rhopilema esculentum has been exploited commercially as a delicious food for a long time. Although the edible and medicinal values of R. esculentum have gained extensive attention, the effects of lipids on its nutritional value have rarely been reported. In the present of study, the lipid profile including lipid classes, fatty acyl compositions, and fatty acid (FA) positions in lipids from different parts (oral arms, umbrella, and mouth stalk) of R. esculentum was explored by ultraperformance liquid chromatography--electrospray ionization--quadrupole time-of-flight mass spectrometry (UPLC-ESI-Q-TOF-MS). More than 87 species from 10 major lipid classes including phosphatidylcholine (PC), lysophosphatidylcholine (LPC), phosphatidylethanolamine (PE), lysophosphatidylethanolamine (LPE), phosphatidylinositol (PI), lysophosphatidylinositol (LPI), phosphatidylserine (PS), ceramide (Cer), ceramide 2-aminoethylphosphonate (CAEP), and triacylglycerol (TAG) were separated and characterized. Semiquantification of individual lipid species in different parts of R. esculentum was also conducted. Results showed that glycerophospholipids (GPLs) enriched in highly unsaturated fatty acids (HUFAs) were the major compenents in all parts of R. esculentum, which accounted for 54-63% of total lipids (TLs). Considering the high level of GPLs and the FA compositions in GPLs, jellyfish R. esculentum might have great potential as a health-promoting food for humans and as a growth-promoting diet for some commercial fish and crustaceans. Meanwhile, LPC, LPE, and LPI showed high levels in oral arms when compared with umbrella and mouth stalk, which may be due to the high proportion of phospholipase A2 (PLA2) in oral arms. Moreover, a high CAEP level was detected in oral arms, which may render cell membranes with resistance to chemical hydrolysis by PLA2. The relatively low TAG content could be associated with specific functions of oral arms.

Oxidation of Octopus vulgaris hemocyanin by nitrogen oxides

DOE Office of Scientific and Technical Information (OSTI.GOV)

Salvato, B.; Giacometti, G.M.; Beltramini, M.

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 coppermore » without an exogenous nitrogen oxide ligand.« less

Reduced salinity increases susceptibility of zooxanthellate jellyfish to herbicide toxicity during a simulated rainfall event.

PubMed

Klein, Shannon G; Pitt, Kylie A; Carroll, Anthony R

2016-02-01

Accurately predicting how marine biota are likely to respond to changing ocean conditions requires accurate simulation of interacting stressors, exposure regimes and recovery periods. Jellyfish populations have increased in some parts of the world and, despite few direct empirical tests, are hypothesised to be increasing because they are robust to a range of environmental stressors. Here, we investigated the effects of contaminated runoff on a zooxanthellate jellyfish by exposing juvenile Cassiopea sp. medusae to a photosystem II (PSII) herbicide, atrazine and reduced salinity conditions that occur following rainfall. Four levels of atrazine (0ngL(-1), 10ngL(-1), 2μgL(-1), 20μgL(-1)) and three levels of salinity (35 ppt, 25 ppt, 17 ppt) were varied, mimicking the timeline of light, moderate and heavy rainfall events. Normal conditions were then slowly re-established over four days to mimic the recovery of the ecosystem post-rain and the experiment continued for a further 7 days to observe potential recovery of the medusae. Pulse-amplitude modulated (PAM) chlorophyll fluorescence, growth and bell contraction rates of medusae were measured. Medusae exposed to the combination of high atrazine and lowest salinity died. After 3 days of exposure, bell contraction rates were reduced by 88% and medusae were 16% smaller in the lowest salinity treatments. By Day 5 of the experiment, all medusae that survived the initial pulse event began to recover quickly. Although atrazine decreased YII under normal salinity conditions, YII was further reduced when medusae were exposed to both low salinity and atrazine simultaneously. Atrazine breakdown products were more concentrated in jellyfish tissues than atrazine at the end of the experiment, suggesting that although bioaccumulation occurred, atrazine was metabolised. Our results suggest that reduced salinity may increase the susceptibility of medusae to herbicide exposure during heavy rainfall events. Copyright © 2015 Elsevier

[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.

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.

Floating nurseries? Scyphozoan jellyfish, their food and their rich symbiotic fauna in a tropical estuary

PubMed Central

Aguirre, Willington; Hopfe, Charlotte; Morales, Diego; Navarrete, Ángela; Tavera, José

2018-01-01

Background The anthropogenic modification of trophic pathways is seemingly prompting the increase of jellyfish populations at the expense of planktivorous fishes. However, gross generalizations are often made because the most basic aspects of trophic ecology and the diverse interactions of jellyfish with fishes remain poorly described. Here we inquire on the dynamics of food consumption of the medusoid stage of the scyphozoan jellyfish Stomolophus meleagris and characterize the traits and diversity of its symbiotic community. Methods S. meleagris and their associated fauna were sampled in surface waters between November 2015 and April 2017 in Málaga Bay, an estuarine system at the Colombian Pacific. Stomach contents of medusae were examined and changes in prey composition and abundance over time analysed using a multivariate approach. The associated fauna was identified and the relationship between the size of medusae and the size those organisms tested using least-square fitting procedures. Results The presence of S. meleagris medusa in surface waters was seasonal. The gut contents analysis revealed that algae, copepods and fish early life stages were the more abundant items, and PERMANOVA analysis showed that the diet differed within the seasons (P(perm) = 0.001) but not between seasons (P(perm) = 0.134). The majority of the collected medusae (50.4%) were associated with individuals of 11 symbiotic species, 95.3% of them fishes, 3.1% crustaceans and 1.6% molluscs. Therefore, this study reports 10 previously unknown associations. The bell diameter of S. meleagris was positively related to the body sizes of their symbionts. However, a stronger fit was observed when the size relationship between S. meleagris and the fish Hemicaranx zelotes was modelled. Discussion The occurrence of S. meleagris was highly seasonal, and the observed patterns of mean body size through the seasons suggested the arrival of adult medusae to the estuary from adjacent waters. The diet

Floating nurseries? Scyphozoan jellyfish, their food and their rich symbiotic fauna in a tropical estuary.

PubMed

Riascos, José M; Aguirre, Willington; Hopfe, Charlotte; Morales, Diego; Navarrete, Ángela; Tavera, José

2018-01-01

The anthropogenic modification of trophic pathways is seemingly prompting the increase of jellyfish populations at the expense of planktivorous fishes. However, gross generalizations are often made because the most basic aspects of trophic ecology and the diverse interactions of jellyfish with fishes remain poorly described. Here we inquire on the dynamics of food consumption of the medusoid stage of the scyphozoan jellyfish Stomolophus meleagris and characterize the traits and diversity of its symbiotic community. S. meleagris and their associated fauna were sampled in surface waters between November 2015 and April 2017 in Málaga Bay, an estuarine system at the Colombian Pacific. Stomach contents of medusae were examined and changes in prey composition and abundance over time analysed using a multivariate approach. The associated fauna was identified and the relationship between the size of medusae and the size those organisms tested using least-square fitting procedures. The presence of S. meleagris medusa in surface waters was seasonal. The gut contents analysis revealed that algae, copepods and fish early life stages were the more abundant items, and PERMANOVA analysis showed that the diet differed within the seasons ( P (perm)  = 0.001) but not between seasons ( P (perm)  = 0.134). The majority of the collected medusae (50.4%) were associated with individuals of 11 symbiotic species, 95.3% of them fishes, 3.1% crustaceans and 1.6% molluscs. Therefore, this study reports 10 previously unknown associations. The bell diameter of S. meleagris was positively related to the body sizes of their symbionts. However, a stronger fit was observed when the size relationship between S. meleagris and the fish Hemicaranx zelotes was modelled. The occurrence of S. meleagris was highly seasonal, and the observed patterns of mean body size through the seasons suggested the arrival of adult medusae to the estuary from adjacent waters. The diet of S. meleagris in the study

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.

Screening of extraction methods for glycoproteins from jellyfish ( Rhopilema esculentum) oral-arms by high performance liquid chromatography

NASA Astrophysics Data System (ADS)

Ren, Guoyan; Li, Bafang; Zhao, Xue; Zhuang, Yongliang; Yan, Mingyan; Hou, Hu; Zhang, Xiukun; Chen, Li

2009-03-01

In order to select an optimum extraction method for the target glycoprotein (TGP) from jellyfish ( Rhopilema esculentum) oral-arms, a high performance liquid chromatography (HPLC)-assay for the determination of the TGP was developed. Purified target glycoprotein was taken as a standard glycoprotein. The results showed that the calibration curves for peak area plotted against concentration for TGP were linear ( r = 0.9984, y = 4.5895 x+47.601) over concentrations ranging from 50 to 400 mgL-1. The mean extraction recovery was 97.84% (CV2.60%). The fractions containing TGP were isolated from jellyfish ( R. esculentum) oral-arms by four extraction methods: 1) water extraction (WE), 2) phosphate buffer solution (PBS) extraction (PE), 3) ultrasound-assisted water extraction (UA-WE), 4) ultrasound-assisted PBS extraction (UA-PE). The lyophilized extract was dissolved in Milli-Q water and analyzed directly on a short TSK-GEL G4000PWXL (7.8 mm×300 mm) column. Our results indicated that the UA-PE method was the optimum extraction method selected by HPLC.

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.

Receptor units responding to movement in the octopus mantle.

PubMed

Boyle, P R

1976-08-01

1. A preparation of the mantle of Octopus which is inverted over a solid support and which exposes the stellate ganglion and associated nerves is described. 2. Afferent activity can be recorded from stellar nerves following electrical stimulation of the pallial nerve. The latency and frequency of the phasic sensory response is correlated with the contraction of the mantle musculature. 3. It is proposed that receptors cells located in the muscle, and their activity following mantle contraction, form part of a sensory feedback system in the mantle. Large, multipolar nerve cells that were found between the two main layers of circular muscle in the mantle could be such receptors.

Studies on the hemolytic activity of tentacle extracts of jellyfish Rhopilema esculentum Kishinouye: application of orthogonal test.

PubMed

Yu, Huahua; Xing, Ronge; Liu, Song; Li, Cuiping; Guo, Zhanyong; Li, Pengcheng

2007-02-20

The present work is first reporting the hemolytic activity of venom from jellyfish Rhopilema esculentum Kishinouye extracted by different phosphate buffer solutions and incubated at different temperature according to the orthogonal test L6(1) x 3(6). Of the seven controllable independent variables, incubated temperature and phenylmethylsulfonyl fluoride (PMSF) had strongest effect on the hemolytic activity.

Pore Water Pumping by Upside-Down Jellyfish

NASA Astrophysics Data System (ADS)

Gaddam, Manikantam; Santhanakrishnan, Arvind

2016-11-01

Patchy aggregations of Cassiopea medusae, commonly called upside-down jellyfish, are found in sheltered marine environments with low-speed ambient flows. These medusae exhibit a sessile, non-swimming lifestyle, and are oriented such that their bells are attached to the substrate and oral arms point towards sunlight. Pulsations of their bells are used to generate currents for suspension feeding. Their pulsations have also been proposed to generate forces that can release sediment locked nutrients into the surrounding water. The goal of this study is to examine pore water pumping by Cassiopea individuals in laboratory aquaria, as a model for understanding pore water pumping in unsteady flows. Planar laser-induced fluorescence (PLIF) measurements were conducted to visualize the release of pore water via bell motion, using fluorescent dye introduced underneath the substrate. 2D particle image velocimetry (PIV) measurements were conducted on the same individuals to correlate PLIF-based concentration profiles with the jets generated by pulsing of medusae. The effects of varying bell diameter on pore water release and pumping currents will be discussed.

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.

First Report of a Peroxiredoxin Homologue in Jellyfish: Molecular Cloning, Expression and Functional Characterization of CcPrx4 from Cyanea capillata

PubMed Central

Ruan, Zengliang; Liu, Guoyan; Wang, Beilei; Zhou, Yonghong; Lu, Jia; Wang, Qianqian; Zhao, Jie; Zhang, Liming

2014-01-01

We first identified and characterized a novel peroxiredoxin (Prx), designated as CcPrx4, from the cDNA library of the tentacle of the jellyfish Cyanea capillata. The full-length cDNA sequence of CcPrx4 consisted of 884 nucleotides with an open reading frame encoding a mature protein of 247 amino acids. It showed a significant homology to peroxiredoxin 4 (Prx4) with the highly conserved F-motif (93FTFVCPTEI101), hydrophobic region (217VCPAGW222), 140GGLG143 and 239YF240, indicating that it should be a new member of the Prx4 family. The deduced CcPrx4 protein had a calculated molecular mass of 27.2 kDa and an estimated isoelectric point of 6.3. Quantitative real-time PCR analysis showed that CcPrx4 mRNA could be detected in all the jellyfish tissues analyzed. CcPrx4 protein was cloned into the expression vector, pET-24a, and expressed in Escherichia coli Rosetta (DE3) pLysS. Recombinant CcPrx4 protein was purified by HisTrap High Performance chelating column chromatography and analyzed for its biological function. The results showed that the purified recombinant CcPrx4 protein manifested the ability to reduce hydrogen peroxide and protect supercoiled DNA from oxidative damage, suggesting that CcPrx4 protein may play an important role in protecting jellyfish from oxidative damage. PMID:24413803

Cytotoxicity and hemolytic activity of jellyfish Nemopilema nomurai (Scyphozoa: Rhizostomeae) venom.

PubMed

Kang, Changkeun; Munawir, Al; Cha, Mijin; Sohn, Eun-Tae; Lee, Hyunkyoung; Kim, Jong-Shu; Yoon, Won Duk; Lim, Donghyun; Kim, Euikyung

2009-07-01

The recent bloom of a giant jellyfish Nemopilema nomurai has caused a danger to sea bathers and fishery damages in the waters of China, Korea, and Japan. The present study investigated the cytotoxic and hemolytic activities of crude venom extract of N. nomurai using a number of in vitro assays. The jellyfish venom showed a much higher cytotoxic activity in H9C2 heart myoblast than in C2C12 skeletal myoblast (LC(50)=2 microg/mL vs. 12 microg/mL, respectively), suggesting its possible in vivo selective toxicity on cardiac tissue. This result is consistent with our previous finding that cardiovascular function is a target of the venom. In order to determine the stability of N. nomurai venom, its cytotoxicity was examined under the various temperature and pH conditions. The activity was relatively well retained at low environmental temperature (or=60 degrees C). In pH stability test, the venom has abruptly lost its activity at low pH environment (pH

Isolation and characterization of 14 tetranucleotide microsatellite loci for the cannonball jellyfish (Stomolophus sp.) by next generation sequencing.

PubMed

Getino-Mamet, Leandro Nicolás; Valdivia-Carrillo, Tania; Gómez Daglio, Liza; García-De León, Francisco Javier

2017-04-01

The Cannonball jellyfish (Stomolophus sp.) is a species of jellyfish with high relevance in artisanal fishing. Studies of their populations do not extend beyond the morphological descriptions knowing that presents a great morphological variability. However, there are no genetic studies to determine the number of independent populations, so microsatellite markers become a suitable option. Since there are no species-specific microsatellite loci, in this paper, 14 new microsatellite loci are characterized. Microsatellite loci were isolated de novo through next generation sequencing, by two runs on Illumina MiSeq. A total of 506,771,269 base pair were obtained, from which 142,616 were microsatellite loci, and 1546 of them could design primers. We tested 14 primer pairs on 32 individuals from Bahía de La Paz, Gulf of California. We observed low genetic variation among loci (mean number of alleles per locus = 4.33, mean observed heterozygosity 0.381, mean expected heterozygosity 0.501). These loci are the first ones described for the species and will be helpful to carry out genetic diversity and population genetics studies.

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

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. © 2013 Elsevier Inc. All rights reserved.

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.

User's manual for a two-dimensional, ground-water flow code on the Octopus computer network

DOE Office of Scientific and Technical Information (OSTI.GOV)

Naymik, T.G.

1978-08-30

A ground-water hydrology computer code, programmed by R.L. Taylor (in Proc. American Society of Civil Engineers, Journal of Hydraulics Division, 93(HY2), pp. 25-33 (1967)), has been adapted to the Octopus computer system at Lawrence Livermore Laboratory. Using an example problem, this manual details the input, output, and execution options of the code.

Determination of the average orientation of DNA in the octopus sperm [ital Eledone] [ital cirrhossa] through polarized light scattering

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shapiro, D.B.; Maestre, M.F.; McClain, W.M.

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 experimentalmore » 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.« less

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

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.

Insecticidal activity of proteinous venom from tentacle of jellyfish Rhopilema esculentum Kishinouye.

PubMed

Yu, Huahua; Liu, Xiguang; Dong, Xiangli; Li, Cuiping; Xing, Ronge; Liu, Song; Li, Pengcheng

2005-11-15

Insecticidal activity of proteinous venom from tentacle of jellyfish Rhopilema esculentum Kishinouye was determined against three pest species, Stephanitis pyri Fabriciusa, Aphis medicaginis Koch, and Myzus persicae Sulzer. R. esculentum full proteinous venom had different insecticidal activity against S. pyri Fabriciusa, A. medicaginis Koch, and M. persicae Sulzer. The 48 h LC50 values were 123.1, 581.6, and 716.3 microg/mL, respectively. Of the three pests, R. esculentum full proteinous venom had the most potent toxicity against S. pyri Fabriciusa, and the corrected mortality recorded at 48 h was 97.86%. So, S. pyri Fabriciusa could be a potential target pest of R. esculentum full proteinous venom.

Complete mitochondrial genome of the moon jellyfish, Aurelia sp. nov. (Cnidaria, Scyphozoa).

PubMed

Hwang, Dae-Sik; Park, Eunji; Won, Yong-Jin; Lee, Jae-Seong

2014-02-01

We sequenced 16,971 bp of the linear mitochondrial DNA of the moon jellyfish Aurelia sp. nov. and characterized it by comparing with Aurelia aurita. They had 13 protein-coding genes (PCGs), 16S rRNA and 12S rRNA with three tRNAs (tRNA-Leu, tRNA-Ser(TGA), tRNA-Met). Both have another two PCGs, orf969 and orf324 with telomeres at both ends. After comparison of Aurelia sp. nov. with Aurelia aurita, we found low-protein similarity of orf969 (59%) and orf324 (75%), respectively, while the other 13 PCGs showed 80% to 98% protein similarities.

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.

Jellyfish Support High Energy Intake of Leatherback Sea Turtles (Dermochelys coriacea): Video Evidence from Animal-Borne Cameras

PubMed Central

Heaslip, Susan G.; Iverson, Sara J.; Bowen, W. Don; James, Michael C.

2012-01-01

The endangered leatherback turtle is a large, highly migratory marine predator that inexplicably relies upon a diet of low-energy gelatinous zooplankton. The location of these prey may be predictable at large oceanographic scales, given that leatherback turtles perform long distance migrations (1000s of km) from nesting beaches to high latitude foraging grounds. However, little is known about the profitability of this migration and foraging strategy. We used GPS location data and video from animal-borne cameras to examine how prey characteristics (i.e., prey size, prey type, prey encounter rate) correlate with the daytime foraging behavior of leatherbacks (n = 19) in shelf waters off Cape Breton Island, NS, Canada, during August and September. Video was recorded continuously, averaged 1:53 h per turtle (range 0:08–3:38 h), and documented a total of 601 prey captures. Lion's mane jellyfish (Cyanea capillata) was the dominant prey (83–100%), but moon jellyfish (Aurelia aurita) were also consumed. Turtles approached and attacked most jellyfish within the camera's field of view and appeared to consume prey completely. There was no significant relationship between encounter rate and dive duration (p = 0.74, linear mixed-effects models). Handling time increased with prey size regardless of prey species (p = 0.0001). Estimates of energy intake averaged 66,018 kJ•d−1 but were as high as 167,797 kJ•d−1 corresponding to turtles consuming an average of 330 kg wet mass•d−1 (up to 840 kg•d−1) or approximately 261 (up to 664) jellyfish•d-1. Assuming our turtles averaged 455 kg body mass, they consumed an average of 73% of their body mass•d−1 equating to an average energy intake of 3–7 times their daily metabolic requirements, depending on estimates used. This study provides evidence that feeding tactics used by leatherbacks in Atlantic Canadian waters are highly profitable and our results are consistent with estimates of mass gain prior to

Flexibly deployed Pax genes in eye development at the early evolution of animals demonstrated by studies on a hydrozoan jellyfish.

PubMed

Suga, Hiroshi; Tschopp, Patrick; Graziussi, Daria F; Stierwald, Michael; Schmid, Volker; Gehring, Walter J

2010-08-10

Pax transcription factors are involved in a variety of developmental processes in bilaterians, including eye development, a role typically assigned to Pax-6. Although no true Pax-6 gene has been found in nonbilateral animals, some jellyfish have eyes with complex structures. In the cubozoan jellyfish Tripedalia, Pax-B, an ortholog of vertebrate Pax-2/5/8, had been proposed as a regulator of eye development. Here we have isolated three Pax genes (Pax-A, Pax-B, and Pax-E) from Cladonema radiatum, a hydrozoan jellyfish with elaborate eyes. Cladonema Pax-A is strongly expressed in the retina, whereas Pax-B and Pax-E are highly expressed in the manubrium, the feeding and reproductive organ. Misexpression of Cladonema Pax-A induces ectopic eyes in Drosophila imaginal discs, whereas Pax-B and Pax-E do not. Furthermore, Cladonema Pax-A paired domain protein directly binds to the 5' upstream region of eye-specific Cladonema opsin genes, whereas Pax-B does not. Our data suggest that Pax-A, but not Pax-B or Pax-E, is involved in eye development and/or maintenance in Cladonema. Phylogenetic analysis indicates that Pax-6, Pax-B, and Pax-A belong to different Pax subfamilies, which diverged at the latest before the Cnidaria-Bilateria separation. We argue that our data, showing the involvement of Pax genes in hydrozoan eye development as in bilaterians, supports the monophyletic evolutionary origin of all animal eyes. We then propose that during the early evolution of animals, distinct classes of Pax genes, which may have played redundant roles at that time, were flexibly deployed for eye development in different animal lineages.

Insights into the transcriptional and translational mechanisms of linear organellar chromosomes in the box jellyfish Alatina alata (Cnidaria: Medusozoa: Cubozoa).

PubMed

Kayal, Ehsan; Bentlage, Bastian; Collins, Allen G

2016-09-01

In most animals, the mitochondrial genome is characterized by its small size, organization into a single circular molecule, and a relative conservation of the number of encoded genes. In box jellyfish (Cubozoa, Cnidaria), the mitochondrial genome is organized into 8 linear mito-chromosomes harboring between one and 4 genes each, including 2 extra protein-coding genes: mt-polB and orf314. Such an organization challenges the traditional view of mitochondrial DNA (mtDNA) expression in animals. In this study, we investigate the pattern of mitochondrial gene expression in the box jellyfish Alatina alata, as well as several key nuclear-encoded molecular pathways involved in the processing of mitochondrial gene transcription. Read coverage of DNA-seq data is relatively uniform for all 8 mito-chromosomes, suggesting that each mito-chromosome is present in equimolar proportion in the mitochondrion. Comparison of DNA and RNA-seq based assemblies indicates that mito-chromosomes are transcribed into individual transcripts in which the beginning and ending are highly conserved. Expression levels for mt-polB and orf314 are similar to those of other mitochondrial-encoded genes, which provides further evidence for them having functional roles in the mitochondrion. Survey of the transcriptome suggests recognition of the mitochondrial tRNA-Met by the cytoplasmic aminoacyl-tRNA synthetase counterpart and C-to-U editing of the cytoplasmic tRNA-Trp after import into the mitochondrion. Moreover, several mitochondrial ribosomal proteins appear to be lost. This study represents the first survey of mitochondrial gene expression of the linear multi-chromosomal mtDNA in box jellyfish (Cubozoa). Future exploration of small RNAs and the proteome of the mitochondrion will test the hypotheses presented herein.

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. © 2013.

UVIT view of ram-pressure stripping in action: Star formation in the stripped gas of the GASP jellyfish galaxy JO201 in Abell 85

NASA Astrophysics Data System (ADS)

George, K.; Poggianti, B. M.; Gullieuszik, M.; Fasano, G.; Bellhouse, C.; Postma, J.; Moretti, A.; Jaffé, Y.; Vulcani, B.; Bettoni, D.; Fritz, J.; Côté, P.; Ghosh, S. K.; Hutchings, J. B.; Mohan, R.; Sreekumar, P.; Stalin, C. S.; Subramaniam, A.; Tandon, S. N.

2018-06-01

Jellyfish are cluster galaxies that experience strong ram-pressure effects that strip their gas. Their Hα images reveal ionized gas tails up to 100 kpc, which could be hosting ongoing star formation. Here we report the ultraviolet (UV) imaging observation of the jellyfish galaxy JO201 obtained at a spatial resolution ˜ 1.3 kpc. The intense burst of star formation happening in the tentacles is the focus of the present study. JO201 is the "UV-brightest cluster galaxy" in Abell 85 (z ˜ 0.056) with knots and streams of star formation in the ultraviolet. We identify star forming knots both in the stripped gas and in the galaxy disk and compare the UV features with the ones traced by Hα emission. Overall, the two emissions remarkably correlate, both in the main body and along the tentacles. Similarly, also the star formation rates of individual knots derived from the extinction-corrected FUV emission agree with those derived from the Hα emission and range from ˜ 0.01 -to- 2.07 M⊙ yr-1. The integrated star formation rate from FUV flux is ˜ 15 M⊙ yr-1. The unprecedented deep UV imaging study of the jellyfish galaxy JO201 shows clear signs of extraplanar star-formation activity due to a recent/ongoing gas stripping event.

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).

In vitro preparation and assessment of radical reducing peptide from Octopus aegina using digestive proteases.

PubMed

Sudhakar, Sekar; Nazeer, Rasool Abdul

2017-07-01

Antioxidant peptides protect biological macromolecules against radical damages. The use of these peptides was evaluated using free radicals scavenging assays [2,2-diphenyl-1 picrylhydrazyl (DPPH) and hydroxyl] with the help of UV-visible and electron spin resonance (ESR) spectroscopy methods. The Octopus aegina mantle protein were tested upon hydrolysis using gastrointestinal enzymes up to 12 h, where pepsin hydrolysate exhibited superior properties (DPPH: 44.39±0.67% and hydroxyl: 38.84±1.07%) compared with trypsin and α-chymotrypsin. Consequently, the antioxidant activity of the purified hydrolysate increased on a successive purification, and the peptide sequence was determined to be 368.9 Da with Gly-Glu-Tyr amino acids. Tripeptide exerted free radical scavenging efficiency in DNA damage, lipid peroxidation and cellular destruction (MCF7 cells) under stress condition. The results obtained with octopus antioxidant peptide suggested its role as an adjunct in food and pharmaceutical industries. Copyright © 2017 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

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

Stable hovering of a jellyfish-like flying machine

PubMed Central

Ristroph, Leif; Childress, Stephen

2014-01-01

Ornithopters, or flapping-wing aircraft, offer an alternative to helicopters in achieving manoeuvrability at small scales, although stabilizing such aerial vehicles remains a key challenge. Here, we present a hovering machine that achieves self-righting flight using flapping wings alone, without relying on additional aerodynamic surfaces and without feedback control. We design, construct and test-fly a prototype that opens and closes four wings, resembling the motions of swimming jellyfish more so than any insect or bird. Measurements of lift show the benefits of wing flexing and the importance of selecting a wing size appropriate to the motor. Furthermore, we use high-speed video and motion tracking to show that the body orientation is stable during ascending, forward and hovering flight modes. Our experimental measurements are used to inform an aerodynamic model of stability that reveals the importance of centre-of-mass location and the coupling of body translation and rotation. These results show the promise of flapping-flight strategies beyond those that directly mimic the wing motions of flying animals. PMID:24430122

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.

Abrupt Changes in the Marmara Pelagic Ecosystem during the recent jellyfish Liriope tetraphylla invasion and mucilage events

NASA Astrophysics Data System (ADS)

Erkan Kideys, Ahmet; Yüksek, Ahsen; Sur, Halil Ibrahim

2013-04-01

In this study, meteorological and hydrographical conditions as well as chemical and biological parameters have been examined for the period 2005-2009 to determine the impact and cause of the massive mucilage phenomenon observed in the Sea of Marmara in October 2007. Results showed that there is a decrease pattern in chl concentration as well as both phytoplankton and zooplankton abundances from August till October in 2007 whilst the jellyfish Liriope tetraphylla had bloom levels. This period coincided with the maximum intensity of pelagic fishing throughout the years. Nitrogen/phosphate ratio increased prior to the mucilage formation. Invasive Liriope tetraphylla abundance increased exponentially in August and died in masses as a result of starvation and meteorological / oceanographic conditions. In October, following the mucilage matter production another new species for the region Gonyaulax fragilis was observed in high abundance through the basin. It is worthy to note that during basin wide samplings conducted in the Sea of Marmara in both 2005 and 2006, high abundances of Liriope tetraphylla have been detected particularly at the northern parts where no mucilage event was observed. We suggest that overfishing in the Sea of Marmara provided a ground for the establishment of the invasive jellyfish and accompanying mucilage event was due to by synergic combinations of several factors.

Characterising the enzymatic profile of crude tentacle extracts from the South Atlantic jellyfish Olindias sambaquiensis (Cnidaria: Hydrozoa).

PubMed

Knittel, Paloma S; Long, Paul F; Brammall, Lucas; Marques, Antonio C; Almeida, Michelle T; Padilla, Gabriel; Moura-da-Silva, Ana M

2016-09-01

Jellyfish venoms are of medical and biotechnological importance, with toxins displaying antimicrobial, analgesic and anti-tumor activities. Although proteolytic enzymes have also been described, detailed characterisation of these proteins is scant in Olindias spp. High throughput mass spectrometry profiling of cnidarian venoms has become increasingly popular since the first description of the proteomic profile of putative toxins isolated from nematocysts of the hydrozoan jellyfish Olindias sambaquiensis describing the presence of orthologous enzymes as presented in venoms of advanced species as snakes. Rigorous bioinformatics analyses can aid functional annotation, but biochemical assays are prerequisite to unambiguously assign toxic function to a peptide or protein. Here we present results that experimentally confirm previously predicted proteomic analysis that crude venom extracts from tentacles of O. sambaquiensis are composed of polypeptides with metalloproteinase, serine proteinase and phospholipases A2 activities. Surprisingly, levels of serine proteinase and phospholipase A2 activities were comparable to those observed in venoms of Bothrops snakes which were used as positive controls in this study. Hence, these data offer new opportunities to explore serine proteinase and phospholipase A2 activities in the clinical sequelae following O. sambaquiensis envenomation, with future possible biopharmaceutical applications. Copyright © 2016 Elsevier Ltd. All rights reserved.

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.

Cardiovascular Effect Is Independent of Hemolytic Toxicity of Tentacle-Only Extract from the Jellyfish Cyanea capillata

PubMed Central

Qianqian, Wang; Sihua, Liu; Yang, Wang; Guoyan, Liu; Jia, Lu; Xuting, Ye; Liming, Zhang

2012-01-01

Our previous studies have confirmed that the crude tentacle-only extract (cTOE) from the jellyfish Cyanea capillata (Cyaneidae) exhibits hemolytic and cardiovascular toxicities simultaneously. So, it is quite difficult to discern the underlying active component responsible for heart injury caused by cTOE. The inactivation of the hemolytic toxicity from cTOE accompanied with a removal of plenty of precipitates would facilitate the separation of cardiovascular component and the investigation of its cardiovascular injury mechanism. In our research, after the treatment of one-step alkaline denaturation followed by twice dialysis, the protein concentration of the treated tentacle-only extract (tTOE) was about 1/3 of cTOE, and SDS-PAGE showed smaller numbers and lower density of protein bands in tTOE. The hemolytic toxicity of tTOE was completely lost while its cardiovascular toxicity was well retained. The observations of cardiac function, histopathology and ultrastructural pathology all support tTOE with significant cardiovascular toxicity. Blood gas indexes and electrolytes changed far less by tTOE than those by cTOE, though still with significant difference from normal. In summary, the cardiovascular toxicity of cTOE can exist independently of the hemolytic toxicity and tTOE can be employed as a better venom sample for further purification and mechanism research on the jellyfish cardiovascular toxic proteins. PMID:22905209

Cloning a Chymotrypsin-Like 1 (CTRL-1) Protease cDNA from the Jellyfish Nemopilema nomurai

PubMed Central

Heo, Yunwi; Kwon, Young Chul; Bae, Seong Kyeong; Hwang, Duhyeon; Yang, Hye Ryeon; Choudhary, Indu; Lee, Hyunkyoung; Yum, Seungshic; Shin, Kyoungsoon; Yoon, Won Duk; Kang, Changkeun; Kim, Euikyung

2016-01-01

An enzyme in a nematocyst extract of the Nemopilema nomurai jellyfish, caught off the coast of the Republic of Korea, catalyzed the cleavage of chymotrypsin substrate in an amidolytic kinetic assay, and this activity was inhibited by the serine protease inhibitor, phenylmethanesulfonyl fluoride. We isolated the full-length cDNA sequence of this enzyme, which contains 850 nucleotides, with an open reading frame of 801 encoding 266 amino acids. A blast analysis of the deduced amino acid sequence showed 41% identity with human chymotrypsin-like (CTRL) and the CTRL-1 precursor. Therefore, we designated this enzyme N. nomurai CTRL-1. The primary structure of N. nomurai CTRL-1 includes a leader peptide and a highly conserved catalytic triad of His69, Asp117, and Ser216. The disulfide bonds of chymotrypsin and the substrate-binding sites are highly conserved compared with the CTRLs of other species, including mammalian species. Nemopilema nomurai CTRL-1 is evolutionarily more closely related to Actinopterygii than to Scyphozoan (Aurelia aurita) or Hydrozoan (Hydra vulgaris). The N. nomurai CTRL1 was amplified from the genomic DNA with PCR using specific primers designed based on the full-length cDNA, and then sequenced. The N. nomurai CTRL1 gene contains 2434 nucleotides and four distinct exons. The 5′ donor splice (GT) and 3′ acceptor splice sequences (AG) are wholly conserved. This is the first report of the CTRL1 gene and cDNA structures in the jellyfish N. nomurai. PMID:27399771

Cloning a Chymotrypsin-Like 1 (CTRL-1) Protease cDNA from the Jellyfish Nemopilema nomurai.

PubMed

Heo, Yunwi; Kwon, Young Chul; Bae, Seong Kyeong; Hwang, Duhyeon; Yang, Hye Ryeon; Choudhary, Indu; Lee, Hyunkyoung; Yum, Seungshic; Shin, Kyoungsoon; Yoon, Won Duk; Kang, Changkeun; Kim, Euikyung

2016-07-05

An enzyme in a nematocyst extract of the Nemopilema nomurai jellyfish, caught off the coast of the Republic of Korea, catalyzed the cleavage of chymotrypsin substrate in an amidolytic kinetic assay, and this activity was inhibited by the serine protease inhibitor, phenylmethanesulfonyl fluoride. We isolated the full-length cDNA sequence of this enzyme, which contains 850 nucleotides, with an open reading frame of 801 encoding 266 amino acids. A blast analysis of the deduced amino acid sequence showed 41% identity with human chymotrypsin-like (CTRL) and the CTRL-1 precursor. Therefore, we designated this enzyme N. nomurai CTRL-1. The primary structure of N. nomurai CTRL-1 includes a leader peptide and a highly conserved catalytic triad of His(69), Asp(117), and Ser(216). The disulfide bonds of chymotrypsin and the substrate-binding sites are highly conserved compared with the CTRLs of other species, including mammalian species. Nemopilema nomurai CTRL-1 is evolutionarily more closely related to Actinopterygii than to Scyphozoan (Aurelia aurita) or Hydrozoan (Hydra vulgaris). The N. nomurai CTRL1 was amplified from the genomic DNA with PCR using specific primers designed based on the full-length cDNA, and then sequenced. The N. nomurai CTRL1 gene contains 2434 nucleotides and four distinct exons. The 5' donor splice (GT) and 3' acceptor splice sequences (AG) are wholly conserved. This is the first report of the CTRL1 gene and cDNA structures in the jellyfish N. nomurai.

Learning from real and tissue-engineered jellyfish: How to design and build a muscle-powered pump at intermediate Reynolds numbers

NASA Astrophysics Data System (ADS)

Nawroth, Janna; Lee, Hyungsuk; Feinberg, Adam; Ripplinger, Crystal; McCain, Megan; Grosberg, Anna; Dabiri, John; Parker, Kit

2012-11-01

Tissue-engineered devices promise to advance medical implants, aquatic robots and experimental platforms for tissue-fluid interactions. The design, fabrication and systematic improvement of tissue constructs, however, is challenging because of the complex interactions of living cell, synthetic materials and their fluid environments. In a proof of concept study we have tissue-engineered a construct that mimics the swimming of a juvenile jellyfish, a simple model system for muscle-powered pumps at intermediate Reynolds numbers with quantifiable fluid dynamics and morphological properties. Optimally designed constructs achieved jellyfish-like swimming and generated biomimetic propulsion and feeding currents. Focusing on the fluid interactions, we discuss failed and successful designs and the lessons learned in the process. The main challenges were (1) to derive a body shape and deformation suitable for effective fluid transport under physiological fluid conditions, (2) to understand the mechanical properties of muscle and bell matrix and device a design capable of the desired deformation, (3) to establish adequate 3D kinematics of power and recovery stroke, and (4) to evaluate the performance of the design.

Selective effects of an octopus toxin on action potentials

PubMed Central

Dulhunty, Angela; Gage, Peter W.

1971-01-01

1. A lethal, water soluble toxin (Maculotoxin, MTX) with a molecular weight less than 540, can be extracted from the salivary glands of an octopus (Hapalochlaena maculosa). 2. MTX blocks action potentials in sartorius muscle fibres of toads without affecting the membrane potential. Delayed rectification is not inhibited by the toxin. 3. At low concentrations (10-6-10-5 g/ml.) MTX blocks action potentials only after a certain number have been elicited. The number of action potentials, which can be defined accurately, depends on the concentration of MTX and the concentration of sodium ions in the extracellular solution. 4. The toxin has no post-synaptic effect at the neuromuscular junction and it is concluded that it blocks neuromuscular transmission by inhibiting action potentials in motor nerve terminals. PMID:4330930

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.

The public health impact of a new simple practical technique for collection and transfer of toxic jellyfish specimens and for nematocyst identification.

PubMed

Thaikruea, Lakkana; Santidherakul, Sineenart

2018-05-01

Our team aimed to create a new, simple, and inexpensive technique for collecting and transferring of toxic jellyfish specimens and for nematocysts identification. We collected tentacles of Chironex spp., Morbakka spp., and Physalia spp., and transferred them from the beaches by standard and by 'vacuum sticky tape' (VST) techniques. For the VST technique, our team placed the sticky tape on a tentacle and then folded it over to seal the tentacle in the equivalent of a vacuum. We kept the VST in room temperature. For nematocyst identification, we placed the VST on a glass microscope slide and took photographs down the microscope's eye piece using a mobile phone camera. The image quality was as good as when produced by standard techniques. Different classes of toxic jellyfish could be identified. Thus, VST is a potential public health breakthrough because it is practical, durable, inexpensive, allows good discrimination. It enables early warning of danger to health and rapid response via social network.

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

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.

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.

[Spectral diversity among the members of the family of Green Fluorescent Protein in hydroid jellyfish (Cnidaria, Hydrozoa)].

PubMed

Ianushevich, Iu G; Shagin, D A; Fradkov, A F; Shakhbazov, K S; Barsova, E V; Gurskaia, N G; Labas, Iu A; Matts, M V; Luk'ianov, k A; Lul'ianov, S A

2005-01-01

The cDNAs encoding the genes of new proteins homologous to the well-known Green Fluorescent Protein (GFP) from the hydroid jellyfish Aequorea victoria were cloned. Two green fluorescent proteins from one un-identified anthojellyfish, a yellow fluorescent protein from Phialidium sp., and a nonfluorescent chromoprotein from another unidentified anthojellyfish were characterized. Thus, a broad diversity of GFP-like proteins among the organisms of the class Hydrozoa in both spectral properties and primary structure was shown.

β adrenergic receptor/cAMP/PKA signaling contributes to the intracellular Ca2+ release by tentacle extract from the jellyfish Cyanea capillata.

PubMed

Wang, Qianqian; Zhang, Hui; Wang, Bo; Wang, Chao; Xiao, Liang; Zhang, Liming

2017-07-25

Intracellular Ca 2+ overload induced by extracellular Ca 2+ entry has previously been confirmed to be an important mechanism for the cardiotoxicity as well as the acute heart dysfunction induced by jellyfish venom, while the underlying mechanism remains to be elucidated. Under extracellular Ca 2+ -free or Ca 2+ -containing conditions, the Ca 2+ fluorescence in isolated adult mouse cardiomyocytes pre-incubated with tentacle extract (TE) from the jellyfish Cyanea capillata and β blockers was scanned by laser scanning confocal microscope. Then, the cyclic adenosine monophosphate (cAMP) concentration and protein kinase A (PKA) activity in primary neonatal rat ventricular cardiomyocytes were determined by ELISA assay. Furthermore, the effect of propranolol against the cardiotoxicity of TE was evaluated in Langendorff-perfused rat hearts and intact rats. The increase of intracellular Ca 2+ fluorescence signal by TE was significantly attenuated and delayed when the extracellular Ca 2+ was removed. The β adrenergic blockers, including propranolol, atenolol and esmolol, partially inhibited the increase of intracellular Ca 2+ in the presence of 1.8 mM extracellular Ca 2+ and completely abolished the Ca 2+ increase under an extracellular Ca 2+ -free condition. Both cAMP concentration and PKA activity were stimulated by TE, and were inhibited by the β adrenergic blockers. Cardiomyocyte toxicity of TE was antagonized by β adrenergic blockers and the PKA inhibitor H89. Finally, the acute heart dysfuction by TE was antagonized by propranolol in Langendorff-perfused rat hearts and intact rats. Our findings indicate that β adrenergic receptor/cAMP/PKA signaling contributes to the intracellular Ca 2+ overload through intracellular Ca 2+ release by TE from the jellyfish C. capillata.

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.

Feeding Currents generated by Cassiopea jellyfish

NASA Astrophysics Data System (ADS)

Gaddam, M. G.; Santhanakrishnan, A.

2016-02-01

Feeding currents generated by organisms dwelling in the benthic boundary layer can enhance nutrient fluxes in coastal habitats with low-speed ambient flows. Patchy aggregations of Cassiopea medusae, commonly referred to as the "upside-down" jellyfish, are seen in sheltered marine environments such as mangrove forests and coral reefs in shallow regions saturated with sunlight. They exhibit a sessile, non-swimming lifestyle, and are oriented such that their bells are attached to the substrate and oral arms directed toward the free surface. Pulsations of their bells drive flow toward and away from the body, assisting in suspension feeding and for exchange of inorganic and organic matter across the water column. The feeding currents generated by aggregations of these medusae and subsequent effects on mixing in the water column have not been examined. We experimentally investigated currents generated by groups of Cassiopea medusae in a low-speed recirculating water tunnel. Multiple medusae grouping arrangements were tested in the tunnel based on time-lapse videos of the organisms obtained overnight in laboratory aquaria. Fluorescent dye introduced underneath the substrate was used to investigate release of porewater via bell motion. Quantitative flow visualization studies of Cassiopea currents were conducted using 2D high-speed particle image velocimetry. Vertical mixing of medusa-induced jets were observed in the presence of minimal background flow. The implications of feeding currents generated by groups of Cassiopea medusae on mixing in the water column will be presented.

Diet Composition and Variability of Wild Octopus vulgaris and Alloteuthis media (Cephalopoda) Paralarvae: a Metagenomic Approach

PubMed Central

Olmos-Pérez, Lorena; Roura, Álvaro; Pierce, Graham J.; Boyer, Stéphane; González, Ángel F.

2017-01-01

The high mortality of cephalopod early stages is the main bottleneck to grow them from paralarvae to adults in culture conditions, probably because the inadequacy of the diet that results in malnutrition. Since visual analysis of digestive tract contents of paralarvae provides little evidence of diet composition, the use of molecular tools, particularly next generation sequencing (NGS) platforms, offers an alternative to understand prey preferences and nutrient requirements of wild paralarvae. In this work, we aimed to determine the diet of paralarvae of the loliginid squid Alloteuthis media and to enhance the knowledge of the diet of recently hatched Octopus vulgaris paralarvae collected in different areas and seasons in an upwelling area (NW Spain). DNA from the dissected digestive glands of 32 A. media and 64 O. vulgaris paralarvae was amplified with universal primers for the mitochondrial gene COI, and specific primers targeting the mitochondrial gene 16S gene of arthropods and the mitochondrial gene 16S of Chordata. Following high-throughput DNA sequencing with the MiSeq run (Illumina), up to 4,124,464 reads were obtained and 234,090 reads of prey were successfully identified in 96.87 and 81.25% of octopus and squid paralarvae, respectively. Overall, we identified 122 Molecular Taxonomic Units (MOTUs) belonging to several taxa of decapods, copepods, euphausiids, amphipods, echinoderms, molluscs, and hydroids. Redundancy analysis (RDA) showed seasonal and spatial variability in the diet of O. vulgaris and spatial variability in A. media diet. General Additive Models (GAM) of the most frequently detected prey families of O. vulgaris revealed seasonal variability of the presence of copepods (family Paracalanidae) and ophiuroids (family Euryalidae), spatial variability in presence of crabs (family Pilumnidae) and preference in small individual octopus paralarvae for cladocerans (family Sididae) and ophiuroids. No statistically significant variation in the

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. Copyright © 2015 Verlag Helvetica Chimica Acta AG, Zürich.

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.

Prokaryotic microbiota in the digestive cavity of the jellyfish Cotylorhiza tuberculata.

PubMed

Cortés-Lara, Sara; Urdiain, Mercedes; Mora-Ruiz, Merit; Prieto, Laura; Rosselló-Móra, Ramon

2015-10-01

The microbiota associated to the gastric cavity of four exemplars of the jellyfish Cotylorhiza tuberculata has been studied by means of cultured-dependent and -independent methods. The pyrosequencing approach rendered a very reduced diversity of Bacteria with four major groups shared by the four exemplars that made up to 95% of the total diversity. The culturing approach recovered low abundant organisms and some of them also detected by the pyrosequencing approach. The major key organisms were related to the genera Spiroplasma, Thalassospira, Tenacibaculum (from the pyrosequencing data), and Vibrio (from the cultivable fraction). Altogether the results indicate that C. tuberculata harbors an associated microbiota of very reduced diversity. On the other hand, some of the major key players may be potential pathogens and the host may serve as dispersal mechanism. Copyright © 2015 Elsevier GmbH. All rights reserved.

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

Jellyfish: the origin and distribution of extreme ram-pressure stripping events in massive galaxy clusters

NASA Astrophysics Data System (ADS)

McPartland, Conor; Ebeling, Harald; Roediger, Elke; Blumenthal, Kelly

2016-01-01

We investigate the observational signatures and physical origin of ram-pressure stripping (RPS) in 63 massive galaxy clusters at z = 0.3-0.7, based on images obtained with the Hubble Space Telescope. Using a training set of a dozen `jellyfish' galaxies identified earlier in the same imaging data, we define morphological criteria to select 211 additional, less obvious cases of RPS. Spectroscopic follow-up observations of 124 candidates so far confirmed 53 as cluster members. For the brightest and most favourably aligned systems, we visually derive estimates of the projected direction of motion based on the orientation of apparent compression shocks and debris trails. Our findings suggest that the onset of these events occurs primarily at large distances from the cluster core (>400 kpc), and that the trajectories of the affected galaxies feature high-impact parameters. Simple models show that such trajectories are highly improbable for galaxy infall along filaments but common for infall at high velocities, even after observational biases are accounted for, provided the duration of the resulting RPS events is ≲500 Myr. We thus tentatively conclude that extreme RPS events are preferentially triggered by cluster mergers, an interpretation that is supported by the disturbed dynamical state of many of the host clusters. This hypothesis implies that extreme RPS might occur also near the cores of merging poor clusters or even merging groups of galaxies. Finally, we present nine additional `jellyfish" galaxies at z > 0.3 discovered by us, thereby doubling the number of such systems known at intermediate redshift.

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.

Evidence of Cnidarians sensitivity to sound after exposure to low frequency noise underwater sources

NASA Astrophysics Data System (ADS)

Solé, Marta; Lenoir, Marc; Fontuño, José Manuel; Durfort, Mercè; van der Schaar, Mike; André, Michel

2016-12-01

Jellyfishes represent a group of species that play an important role in oceans, particularly as a food source for different taxa and as a predator of fish larvae and planktonic prey. The massive introduction of artificial sound sources in the oceans has become a concern to science and society. While we are only beginning to understand that non-hearing specialists like cephalopods can be affected by anthropogenic noises and regulation is underway to measure European water noise levels, we still don’t know yet if the impact of sound may be extended to other lower level taxa of the food web. Here we exposed two species of Mediterranean Scyphozoan medusa, Cotylorhiza tuberculata and Rhizostoma pulmo to a sweep of low frequency sounds. Scanning electron microscopy (SEM) revealed injuries in the statocyst sensory epithelium of both species after exposure to sound, that are consistent with the manifestation of a massive acoustic trauma observed in other species. The presence of acoustic trauma in marine species that are not hearing specialists, like medusa, shows the magnitude of the problem of noise pollution and the complexity of the task to determine threshold values that would help building up regulation to prevent permanent damage of the ecosystems.

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.

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.

Pelagia benovici sp. nov. (Cnidaria, Scyphozoa): a new jellyfish in the Mediterranean Sea.

PubMed

Piraino, Stefano; Aglieri, Giorgio; Martell, Luis; Mazzoldi, Carlotta; Melli, Valentina; Milisenda, Giacomo; Scorrano, Simonetta; Boero, Ferdinando

2014-05-07

A bloom of an unknown semaestome jellyfish species was recorded in the North Adriatic Sea from September 2013 to early 2014. Morphological analysis of several specimens showed distinct differences from other known semaestome species in the Mediterranean Sea and unquestionably identified them as belonging to a new pelagiid species within genus Pelagia. The new species is morphologically distinct from P. noctiluca, currently the only recognized valid species in the genus, and from other doubtful Pelagia species recorded from other areas of the world. Molecular analyses of mitochondrial cytochrome c oxidase subunit I (COI) and nuclear 28S ribosomal DNA genes corroborate its specific distinction from P. noctiluca and other pelagiid taxa, supporting the monophyly of Pelagiidae. Thus, we describe Pelagia benovici sp. nov. Piraino, Aglieri, Scorrano & Boero.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

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 accessingmore » 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.« less

Temperature-dependent settlement of planula larvae of two scyphozoan jellyfish from the North Sea

NASA Astrophysics Data System (ADS)

Gambill, Maria; McNaughton, Sadie L.; Kreus, Markus; Peck, Myron A.

2018-02-01

Exploring the settlement dynamics of the planula larvae is critical to understanding the establishment of polyp populations that can give rise to blooms of scyphozoan jellyfish. We conducted experiments to examine the effects of temperature on settlement of planulae of the scyphozoans Cyanea lamarckii and Chrysaora hysoscella, two jellyfish commonly encountered within the North Sea. When provided immediate access to substrate, larvae of C. lamarckii were able to settle at each of 12 temperatures between 9 and 27 °C. Most settlement occurred within the first five days and warmer temperatures were not only associated with decreased time to settlement but also increased settlement success. When not allowed access to substrate and maintained in the water column, planula larvae remained competent to settle for 21, 21 and 14 days at 11.3, 13.4 and 19.4 °C, respectively. Based on these maximum times of competency, hydrodynamic model simulations suggested that the planula larvae of C. lamarckii released in May could be transported up to 100 km before settlement. A substrate choice experiment indicated that larvae of C. hysoscella settled in similar numbers onto PET, wood and concrete. Settlement was highest at 20 °C and a 12/12 light/dark regime and lower at 10 °C and 15 °C in total darkness. The results of all three experiments suggest that projected warming of the North Sea will not impede the settlement of planula larvae of resident C. lamarckii and C. hysoscella populations. Species- and/or population-specific differences may exist in the ecophysiology of planula larvae and additional experiments are needed to understand the mechanisms promoting the establishment of new benthic populations of polyps. That information, combined with process knowledge on the productivity of benthic polyps, will be needed to better understand and predict climate-dependent changes in the production of scyphozoans and other gelatinous plankton.

Persian Gulf Jellyfish (Cassiopea andromeda) Venom Fractions Induce Selective Injury and Cytochrome C Release in Mitochondria Obtained from Breast Adenocarcinoma Patients

PubMed

Mirshamsi, Mohammad Reza; Omranipour, Ramesh; Vazirizadeh, Amir; Fakhri, Amir; Zangeneh, Fatemeh; Mohebbi, Gholam Hussain; Seyedian, Ramin; Pourahmad, Jalal

2017-01-01

Objective: This study was conducted to investigate whether fractions of jellyfish Cassiope andromeda venom, could selectively induce toxicity on mitochondria isolated from cancer tissue of patients with breast adenocarcinomas. Methods: Firstly, we extracted two fractions, (f1 and f2) from crude jellyfish venom by gel filtration on Sephadex G-200.Then different dilutions of these extracted fractions were applied to mitochondria isolated from human breast tumoral- and extra-tumoral tissues. Parameters of mitochondrial toxicity including generation of reactive oxygen species (ROS), mitochondrial membrane potential (MMP) collapse, swelling, cytochrome c release, activation of caspase3 and apoptosis were then assayed. Result: Our results demonstrate that fraction 2 of Cassiopea andromeda crude venom significantly (P<0.05) decreased mitochondrial succinate dehydrogenase activity, increased mitochondrial ROS production, induced mitochondrial swelling, MMP collapse and cytochrome c release, activated caspase3 and induced apoptosis only in tumoral mitochondria, and not in mitochondria obtained from extra-tumoral tissue (P<0.05). Conclusion: In conclusion this study suggested that fraction 2 of Cassiopea andromeda crude venom selectively induces ROS mediated cytotoxicity by directly targeting mitochondria isolated from human breast tumor tissue. Creative Commons Attribution License

Persian Gulf Jellyfish (Cassiopea andromeda) Venom Fractions Induce Selective Injury and Cytochrome C Release in Mitochondria Obtained from Breast Adenocarcinoma Patients

PubMed Central

Mirshamsi, Mohammad Reza; Omranipour, Ramesh; Vazirizadeh, Amir; Fakhri, Amir; Zangeneh, Fatemeh; Mohebbi, Gholam Hussain; Seyedian, Ramin; Pourahmad, Jalal

2017-01-01

Objective: This study was conducted to investigate whether fractions of jellyfish Cassiope andromeda venom, could selectively induce toxicity on mitochondria isolated from cancer tissue of patients with breast adenocarcinomas. Methods: Firstly, we extracted two fractions, (f1 and f2) from crude jellyfish venom by gel filtration on Sephadex G-200. Then different dilutions of these extracted fractions were applied to mitochondria isolated from human breast tumoral- and extra-tumoral tissues. Parameters of mitochondrial toxicity including generation of reactive oxygen species (ROS), mitochondrial membrane potential (MMP) collapse, swelling, cytochrome c release, activation of caspase3 and apoptosis were then assayed. Result: Our results demonstrate that fraction 2 of Cassiopea andromeda crude venom significantly (P<0.05) decreased mitochondrial succinate dehydrogenase activity, increased mitochondrial ROS production, induced mitochondrial swelling, MMP collapse and cytochrome c release, activated caspase3 and induced apoptosis only in tumoral mitochondria, and not in mitochondria obtained from extra-tumoral tissue (P<0.05). Conclusion: In conclusion this study suggested that fraction 2 of Cassiopea andromeda crude venom selectively induces ROS mediated cytotoxicity by directly targeting mitochondria isolated from human breast tumor tissue. PMID:28240847

Indoles induce metamorphosis in a broad diversity of jellyfish, but not in a crown jelly (Coronatae).

PubMed

Helm, Rebecca R; Dunn, Casey W

2017-01-01

Many animals go through one or more metamorphoses during their lives, however, the molecular underpinnings of metamorphosis across diverse species are not well understood. Medusozoa (Cnidaria) is a clade of animals with complex life cycles, these life cycles can include a polyp stage that metamorphoses into a medusa (jellyfish). Medusae are produced through a variety of different developmental mechanisms-in some species polyps bud medusae (Hydrozoa), in others medusae are formed through polyp fission (Scyphozoa), while in others medusae are formed through direct transformation of the polyp (Cubozoa). To better understand the molecular mechanisms that may coordinate these different forms of metamorphosis, we tested two compounds first identified to induce metamorphosis in the moon jellyfish Aurelia aurita (indomethacin and 5-methoxy-2-methylindole) on a broad diversity of medusozoan polyps. We discovered that indole-containing compounds trigger metamorphosis across a broad diversity of species. All tested discomedusan polyps metamorphosed in the presence of both compounds, including species representatives of several major lineages within the clade (Pelagiidae, Cyaneidae, both clades of Rhizostomeae). In a cubozoan, low levels of 5-methoxy-2-methylindole reliably induced complete and healthy metamorphosis. In contrast, neither compound induced medusa metamorphosis in a coronate scyphozoan, or medusa production in either hydrozoan tested. Our results support the hypothesis that metamorphosis is mediated by a conserved induction pathway within discomedusan scyphozoans, and possibly cubozoans. However, failure of these compounds to induce metamorphosis in a coronate suggests this induction mechanism may have been lost in this clade, or is convergent between Scyphozoa and Cubozoa.

Indoles induce metamorphosis in a broad diversity of jellyfish, but not in a crown jelly (Coronatae)

PubMed Central

Dunn, Casey W.

2017-01-01

Many animals go through one or more metamorphoses during their lives, however, the molecular underpinnings of metamorphosis across diverse species are not well understood. Medusozoa (Cnidaria) is a clade of animals with complex life cycles, these life cycles can include a polyp stage that metamorphoses into a medusa (jellyfish). Medusae are produced through a variety of different developmental mechanisms—in some species polyps bud medusae (Hydrozoa), in others medusae are formed through polyp fission (Scyphozoa), while in others medusae are formed through direct transformation of the polyp (Cubozoa). To better understand the molecular mechanisms that may coordinate these different forms of metamorphosis, we tested two compounds first identified to induce metamorphosis in the moon jellyfish Aurelia aurita (indomethacin and 5-methoxy-2-methylindole) on a broad diversity of medusozoan polyps. We discovered that indole-containing compounds trigger metamorphosis across a broad diversity of species. All tested discomedusan polyps metamorphosed in the presence of both compounds, including species representatives of several major lineages within the clade (Pelagiidae, Cyaneidae, both clades of Rhizostomeae). In a cubozoan, low levels of 5-methoxy-2-methylindole reliably induced complete and healthy metamorphosis. In contrast, neither compound induced medusa metamorphosis in a coronate scyphozoan, or medusa production in either hydrozoan tested. Our results support the hypothesis that metamorphosis is mediated by a conserved induction pathway within discomedusan scyphozoans, and possibly cubozoans. However, failure of these compounds to induce metamorphosis in a coronate suggests this induction mechanism may have been lost in this clade, or is convergent between Scyphozoa and Cubozoa. PMID:29281657

A Case of Delayed Flare-up Allergic Dermatitis Caused by Jellyfish Sting.

PubMed

Manabe, Yasuaki; Mabuchi, Tomotaka; Kawai, Mayu; Ota, Tami; Ikoma, Norihiro; Ozawa, Akira; Horita, Takushi

2014-09-20

A 7-year-old boy, taking lessons at a yacht school at Enoshima in Kanagawa prefecture in Japan, recognized a linear eruption on his left lower leg during practice in August 2012. As it gradually enlarged, he visited a local medical clinic. The eruption initially improved with topical treatment but exacerbated in October of the same year. Although topical treatment was started again, there was minimal improvement, so the patient visited our hospital in December. At his first visit, he had a hard linear nodule on his left lower leg, and papules with excoriation were scattered over the lower limbs. Considering eczema, topical steroid treatment and occlusive dressing technique were started but the nodule remained. Based on the clinical course, clinical features, and laboratory findings, the lesion was considered to be delayed flare-up allergic dermatitis caused by a jellyfish sting [1].

Factors affecting the protease activity of venom from jellyfish Rhopilema esculentum Kishinouye.

PubMed

Li, Cuiping; Yu, Huahua; Liu, Song; Xing, Ronge; Guo, Zhanyong; Li, Pengcheng

2005-12-15

In this paper, the effects of some chemical and physical factors such as temperature, pH values, glycerol, and divalent metal cations on the protease activity of venom from jellyfish, Rhopilema esculentum Kishinouye, were assayed. Protease activity was dependent on temperature and pH values. Zn(2+), Mg(2+), and Mn(2+) in sodium phosphate buffer (0.02M, pH 8.0) could increase protease activity. Mn(2+) had the best effects among the three metal cations and the effect was about 20 times of that of Zn(2+) or Mg(2+) and its maximal protease activity was 2.3x10(5)U/mL. EDTA could increase protease activity. PMSF had hardly affected protease activity. O-Phenanthroline and glycerol played an important part in inhibiting protease activity and their maximal inhibiting rates were 87.5% and 82.1%, respectively.

Nitrogen and phosphorus budget of a polyculture system of sea cucumber ( Apostichopus japonicus), jellyfish ( Rhopilema esculenta) and shrimp ( Fenneropenaeus chinensis)

NASA Astrophysics Data System (ADS)

Li, Junwei; Dong, Shuanglin; Gao, Qinfeng; Zhu, Changbo

2014-06-01

The nitrogen (N) and phosphorus (P) budget and the ecological efficiency of a polyculture system of sea cucumber ( Apostichopus japonicus), jellyfish ( Rhopilema esculenta) and shrimp ( Fenneropenaeus chinensis) were studied in a cofferdam, 120.2 ha in size. The nutrients were supplied by spring tide inflow. In total, 139600 kg N yr-1 and 9730 kg P yr-1 input to the system; while 118900 kg N yr-1 and 2840 kg P yr-1 outflowed from the system concurrently, thus the outflow was 85.7% (N) and 29.2% (P) of inflow. The production of N and P was 889.5 kg yr-1 and 49.28 kg yr-1 (sea cucumber) and 204 kg yr-1 and 18.03 kg yr-1 (jellyfish and shrimp), respectively. The utilization rate of N and P by polycultured animals was 7.8‰ and 6.9‰, respectively, 21.9% and 38% higher than that of monocultured sea cucumber. Our results indicated that the polyculture system was an efficient culture system of animals and a remediation system of coastal environment as well; it scavenged 14.3% and 70.8% of N and P, respectively. Such an ecological efficiency may be improved further by increasing either the stocking density or the size of sea cucumber or both.

Cell tracking supports secondary gastrulation in the moon jellyfish Aurelia.

PubMed

Gold, David A; Nakanishi, Nagayasu; Hensley, Nicholai M; Hartenstein, Volker; Jacobs, David K

2016-11-01

The moon jellyfish Aurelia exhibits a dramatic reorganization of tissue during its metamorphosis from planula larva to polyp. There are currently two competing hypotheses regarding the fate of embryonic germ layers during this metamorphosis. In one scenario, the original endoderm undergoes apoptosis and is replaced by a secondary endoderm derived from ectodermal cells. In the second scenario, both ectoderm and endoderm remain intact through development. In this study, we performed a pulse-chase experiment to trace the fate of larval ectodermal cells. We observed that prior to metamorphosis, ectodermal cells that proliferated early in larval development concentrate at the future oral end of the polyp. During metamorphosis, these cells migrate into the endoderm, extending all the way to the aboral portion of the gut. We therefore reject the hypothesis that larval endoderm remains intact during metamorphosis and provide additional support for the "secondary gastrulation" hypothesis. Aurelia appears to offer the first and only described case where a cnidarian derives its endoderm twice during normal development, adding to a growing body of evidence that germ layers can be dramatically reorganized in cnidarian life cycles.

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

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

Marine antivenoms.

PubMed

Currie, Bart J

2003-01-01

There is an enormous diversity and complexity of venoms and poisons in marine animals. Fatalities have occurred from envenoming by sea snakes, jellyfish, venomous fish such as stonefish, cone snails, and blue-ringed octopus. Deaths have also followed ingestion of toxins in shellfish, puffer fish (Fugu), and ciguatoxin-containing fish. However antivenoms are generally only available for envenoming by certain sea snakes, the major Australian box jellyfish (Chironex fleckeri) and stonefish. There have been difficulties in characterizing the toxins of C. fleckeri venom, and there are conflicting animals studies on the efficacy of C. fleckeri antivenom. The vast majority of C. fleckeri stings are not life-threatening, with painful skin welts the major finding. However fatalities that do occur usually do so within 5 to 20 minutes of the sting. This unprecedented rapid onset of cardiotoxicity in clinical envenoming suggests that antivenom may need to be given very early (within minutes) and possibly in large doses if a life is to be saved. Forty years of anecdotal experience supports the beneficial effect of stonefish antivenom in relieving the excruciating pain after stonefish spine penetration. It remains uncertain whether stonefish antivenom is efficacious in stings from spines of other venomous fish, and the recommendation of giving the antivenom intramuscularly needs reassessment.

Heavy metals affect nematocysts discharge response and biological activity of crude venom in the jellyfish Pelagia noctiluca (Cnidaria, Scyphozoa).

PubMed

Morabito, Rossana; Dossena, Silvia; La Spada, Giuseppa; Marino, Angela

2014-01-01

Pollution of marine ecosystems and, specifically, heavy metals contamination may compromise the physiology of marine animals with events occurring on a cellular and molecular level. The present study focuses on the effect of short-term exposure to heavy metals like Zinc, Cadmium, Cobalt and Lanthanum (2-10 mM) on the homeostasis of Pelagia noctiluca (Cnidaria, Scyphozoa), a jellyfish abundant in the Mediterranean sea. This species possesses stinging organoids, termed nematocysts, whose discharge and concomitant delivery of venom underlie the survival of all Cnidaria. Nematocysts discharge response, elicited by combined chemico-physical stimulation, was verified on excised oral arms exposed to heavy metals for 20 min. In addition, the hemolytic activity of toxins, contained in the crude venom extracted from nematocysts isolated from oral arms, was tested on human erythrocytes, in the presence of heavy metals or their mixture. Treatment with heavy metals significantly inhibited both nematocysts discharge response and hemolytic activity of crude venom, in a dose-dependent manner, not involving oxidative events, that was irreversible in the case of Lanthanum. Our findings show that the homeostasis of Pelagia noctiluca, in terms of nematocysts discharge capability and effectiveness of venom toxins, is dramatically and rapidly compromised by heavy metals and confirm that this jellyfish is eligible as a model for ecotoxicological investigations. © 2014 S. Karger AG, Basel.

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. Copyright © 2012 Elsevier Ltd. All rights reserved.

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

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

Cellular respiration, oxygen consumption, and trade-offs of the jellyfish Cassiopea sp. in response to temperature change

NASA Astrophysics Data System (ADS)

Aljbour, Samir M.; Zimmer, Martin; Kunzmann, Andreas

2017-10-01

Pelagic jellyfish blooms are increasing worldwide as a potential response to climate-change. However, virtually nothing is known about physiological responses of jellyfish to e.g. sudden changes in water temperature due to extreme weather events. When confronted with a sudden decrease or increase in water temperature by 6 °C, medusae of Cassiopea sp. exhibited a strong response in locomotor activity (i.e., bell pulsation increased and decreased by ca. 37 and 46% in hot and cold acute (2 h) treatments, respectively) relative to control. Although medusae significantly gained in body mass (wet weight) upon chronic (2 weeks) heat treatment, their body size (e.g., bell diameter) did not change over this time interval. In contrast, chronic cold treatment resulted in both significant shrinking (reduced diameter) and mass loss. Measurements of mitochondrial electron transport system (ETS) activities and rate of respiratory oxygen uptake (MO2) are good estimates of energy consumption and the potential aerobic metabolic rates of an organism. While both acute treatments significantly increased ETS-activities, acclimation over two weeks resulted in a drop in activities to the control levels. Whereas acute heat treatment significantly increased MO2, chronic exposure resulted in significant MO2 decrease compared to control; however no changes in MO2 could be observed in both acute and chronic cold treatments. Overall these results suggest an enhanced growth in response to global warming, whereas low temperatures may set the limits for successful invasion of Cassiopea into colder water bodies. Our results provide a framework for understanding the physiological tolerance of Cassiopea under possible future climate changes.

Box Jellyfish Alatina alata Has a Circumtropical Distribution.

PubMed

Lawley, Jonathan W; Ames, Cheryl Lewis; Bentlage, Bastian; Yanagihara, Angel; Goodwill, Roger; Kayal, Ehsan; Hurwitz, Kikiana; Collins, Allen G

2016-10-01

Species of the box jellyfish (Cubozoa) genus Alatina are notorious for their sting along the beaches of several localities of the Atlantic and Pacific. These species include Alatina alata on the Caribbean Island of Bonaire (the Netherlands), A. moseri in Hawaii, and A. mordens in Australia. Most cubozoans inhabit coastal waters, but Alatina is unusual in that specimens have also been collected in the open ocean at great depths. Alatina is notable in that populations form monthly aggregations for spermcast mating in conjunction with the lunar cycle. Nominal species are difficult to differentiate morphologically, and it has been unclear whether they are distinct or a single species with worldwide distribution. Here we report the results of a population genetic study, using nuclear and mitochondrial sequence data from four geographical localities. Our analyses revealed a general lack of geographic structure among Alatina populations, and slight though significant isolation by distance. These data corroborate morphological and behavioral similarities observed in the geographically disparate localities, and indicate the presence of a single, pantropically distributed species, Alatina alata. While repeated, human-mediated introductions of A. alata could explain the patterns we have observed, it seems more likely that genetic metapopulation cohesion is maintained via dispersal through the swimming medusa stage, and perhaps via dispersal of encysted planulae, which are described here for the first time in Alatina.

Abundant box jellyfish, Chironex sp. (Cnidaria: Cubozoa: Chirodropidae), discovered at depths of over 50 m on western Australian coastal reefs.

PubMed

Keesing, John K; Strzelecki, Joanna; Stowar, Marcus; Wakeford, Mary; Miller, Karen J; Gershwin, Lisa-Ann; Liu, Dongyan

2016-02-29

Box jellyfish cause human fatalities and have a life cycle and habit associated with shallow waters (<5 m) in mangrove creeks, coastal beaches, embayments. In north-western Australia, tow video and epibenthic sled surveys discovered large numbers (64 in a 1500 m tow or 0.05 m(-2)) of Chironex sp. very near to the benthos (<50 cm) at depths of 39-56 m. This is the first record of a population of box jellyfish closely associated with the benthos at such depths. Chironex were not widespread, occurring only in 2 of 33 tow videos and 3 of 41 epibenthic sleds spread over 2000 km(2). All Chironex filmed or captured were on low to medium relief reefs with rich filter feeder communities. None were on soft sediment habitat despite these habitats comprising 49% of all sites. The importance of the reef habitat to Chironex remains unclear. Being associated with filter feeder communities might represent a hazard, and other studies have shown C. fleckeri avoid habitats which represent a risk of entanglement of their tentacles. Most of our observations were made during the period of lowest tidal current flow in the morning. This may represent a period favourable for active hunting for prey close to the seabed.

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 (MgCl 2 ) 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 MgCl 2 formulations had an effect on cardiac function in vitro and, if so, could this impact recovery and (b) direct effects of MgCl 2 formulations on cardiac function. In vitro hearts removed from animals exposed in vivo to 3.5% MgCl 2 in sea water (20 min) or to a mixture of MgCl 2 + 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% MgCl 2 (1:1, sea water: distilled water, 20 min) produced a significant impairment of the Frank-Starling response as did 45 min exposure to the MgCl 2 + ethanol mixture. Perfusion of the isolated heart with MgCl 2 ± 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 MgCl 2 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 MgCl 2 as anesthetics in octopus. Overall, provided that the in vivo exposure to 3.5% MgCl 2 in sea water or to a mixture of MgCl 2 + ethanol is limited to ~20 min, residual effects on cardiac function are unlikely to impact post-anesthetic recovery.

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.

Factors influencing hemolytic activity of venom from the jellyfish Rhopilema esculentum Kishinouye.

PubMed

Yu, Huahua; Li, Cuiping; Li, Ronggui; Xing, Ronge; Liu, Song; Li, Pengcheng

2007-07-01

In this study, hemolytic activity of venom from the jellyfish Rhopilema esculentum Kishinouye and some factors affecting it were assayed. The HU(50) of R. esculentum full venom (RFV) against chicken erythrocytes was 3.40 microg/ml and a Hill coefficient value was 1.73 suggesting at least two molecules participated in hemolytic activity. The hemolytic activity of RFV was affected by some chemical and physical factors such as divalent cations, EDTA, (NH(4))(2)SO(4), pH and temperature. In the presence of Mg(2+), Cu(2+), Zn(2+), Fe(2+), Ca(2+) (>or=2 mM), Mn(2+) ((>or=1 mM), EDTA ((>or=2 mM) and (NH(4))(2)SO(4), the hemolytic activity of RFV was reduced. RFV had strong hemolytic activity at the pH 6-10 and the hemolytic ratios were 0.95-1.19. Hemolytic activity was temperature-sensitive and when RFV was pre-incubated at temperatures over 40 degrees C, it was sharply reduced.

Structural characterization and immunomodulatory activity of a new polysaccharide from jellyfish.

PubMed

Li, Qiang-Ming; Wang, Jing-Fei; Zha, Xue-Qiang; Pan, Li-Hua; Zhang, Hai-Lin; Luo, Jian-Ping

2017-03-01

A new polysaccharide (JSP-11) with a molecular weight of 1.25×10 6 Da was extracted and purified from jellyfish. Monosaccharide analysis showed that JSP-11 was composed of mannose, galactose and glucuronic acid with a molar ratio of 2.18:1.00:1.94. According to the analysis of fourier transform-infrared spectroscopy, methylation analysis, and NMR spectroscopy, JSP-11 was determined to contain a linear backbone which consisted of (1→3,6)-linked β-d-Manp and (1→6)-linked β-d-Galp. The branch of (1→)-linked α-d-GlcpA was attached to the C-3 position of (1→3,6)-linked β-d-Manp in the backbone. The immunomodulatory assay exhibited that JSP-11 could significantly enhance the viability of RAW 264.7 macrophage cells, and promote the release of NO, TNF-α, and IL-1β via activating NF-κB, MAPKs and PI3K/Akt signal pathways. Copyright © 2016 Elsevier Ltd. All rights reserved.

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.

First evidence of inbreeding, relatedness and chaotic genetic patchiness in the holoplanktonic jellyfish Pelagia noctiluca (Scyphozoa, Cnidaria).

PubMed

Aglieri, Giorgio; Papetti, Chiara; Zane, Lorenzo; Milisenda, Giacomo; Boero, Ferdinando; Piraino, Stefano

2014-01-01

Genetic drift and non-random mating seldom influence species with large breeding populations and high dispersal potential, characterized by unstructured gene pool and panmixia at a scale lower than the minimum dispersal range of individuals. In the present study, a set of nine microsatellite markers was developed and used to investigate the spatio-temporal genetic patterns of the holoplanktonic jellyfish Pelagia noctiluca (Scyphozoa) in the Southern Tyrrhenian Sea. Homozygote excess was detected at eight loci, and individuals exhibited intra-population relatedness higher than expected by chance in at least three samples. This result was supported by the presence of siblings in at least 5 out 8 samples, 4 of which contained full-sib in addition to half-sib dyads. Having tested and ruled out alternative explanations as null alleles, our results suggest the influence of reproductive and behavioural features in shaping the genetic structure of P. noctiluca, as outcomes of population genetics analyses pointed out. Indeed, the genetic differentiation among populations was globally small but highlighted: a) a spatial genetic patchiness uncorrelated with distance between sampling locations, and b) a significant genetic heterogeneity between samples collected in the same locations in different years. Therefore, despite its extreme dispersal potential, P. noctiluca does not maintain a single homogenous population, but rather these jellyfish appear to have intra-bloom localized recruitment and/or individual cohesiveness, whereby siblings more likely swarm together as a single group and remain close after spawning events. These findings provide the first evidence of family structures and consequent genetic patchiness in a species with highly dispersive potential throughout its whole life cycle, contributing to understanding the patterns of dispersal and connectivity in marine environments.

First Evidence of Inbreeding, Relatedness and Chaotic Genetic Patchiness in the Holoplanktonic Jellyfish Pelagia noctiluca (Scyphozoa, Cnidaria)

PubMed Central

Aglieri, Giorgio; Papetti, Chiara; Zane, Lorenzo; Milisenda, Giacomo; Boero, Ferdinando; Piraino, Stefano

2014-01-01

Genetic drift and non-random mating seldom influence species with large breeding populations and high dispersal potential, characterized by unstructured gene pool and panmixia at a scale lower than the minimum dispersal range of individuals. In the present study, a set of nine microsatellite markers was developed and used to investigate the spatio-temporal genetic patterns of the holoplanktonic jellyfish Pelagia noctiluca (Scyphozoa) in the Southern Tyrrhenian Sea. Homozygote excess was detected at eight loci, and individuals exhibited intra-population relatedness higher than expected by chance in at least three samples. This result was supported by the presence of siblings in at least 5 out 8 samples, 4 of which contained full-sib in addition to half-sib dyads. Having tested and ruled out alternative explanations as null alleles, our results suggest the influence of reproductive and behavioural features in shaping the genetic structure of P. noctiluca, as outcomes of population genetics analyses pointed out. Indeed, the genetic differentiation among populations was globally small but highlighted: a) a spatial genetic patchiness uncorrelated with distance between sampling locations, and b) a significant genetic heterogeneity between samples collected in the same locations in different years. Therefore, despite its extreme dispersal potential, P. noctiluca does not maintain a single homogenous population, but rather these jellyfish appear to have intra-bloom localized recruitment and/or individual cohesiveness, whereby siblings more likely swarm together as a single group and remain close after spawning events. These findings provide the first evidence of family structures and consequent genetic patchiness in a species with highly dispersive potential throughout its whole life cycle, contributing to understanding the patterns of dispersal and connectivity in marine environments. PMID:24977703

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

You Are What You Eat: A Genomic Analysis of the Gut Microbiome of Captive and Wild Octopus vulgaris Paralarvae and Their Zooplankton Prey.

PubMed

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.

Antihypertensive effect of long-term oral administration of jellyfish (Rhopilema esculentum) collagen peptides on renovascular hypertension.

PubMed

Zhuang, Yongliang; Sun, Liping; Zhang, Yufeng; Liu, Gaoxiang

2012-02-01

Antihypertensive effect of long-term oral administration of jellyfish (Rhopilema esculentum) collagen peptides (JCP) on renovascular hypertension rats (RVHs) was evaluated. The systolic blood pressure and diastolic blood pressure of the RVHs were significantly reduced with administration of JCP (p < 0.05), compared with model control group. However, the arterial blood pressure of normal rats showed no significant changes during long-term oral treatment with high dose JCP (p > 0.05). Furthermore, effect of JCP on angiotensin II (Ang II) concentration of plasma had no significance (p > 0.05), but JCP significantly inhibited the Ang II concentration in RVHs' kidney (p < 0.05). The kidney should be the target site of JCP.

Antihypertensive Effect of Long-Term Oral Administration of Jellyfish (Rhopilema esculentum) Collagen Peptides on Renovascular Hypertension

PubMed Central

Zhuang, Yongliang; Sun, Liping; Zhang, Yufeng; Liu, Gaoxiang

2012-01-01

Antihypertensive effect of long-term oral administration of jellyfish (Rhopilema esculentum) collagen peptides (JCP) on renovascular hypertension rats (RVHs) was evaluated. The systolic blood pressure and diastolic blood pressure of the RVHs were significantly reduced with administration of JCP (p < 0.05), compared with model control group. However, the arterial blood pressure of normal rats showed no significant changes during long-term oral treatment with high dose JCP (p > 0.05). Furthermore, effect of JCP on angiotensin II (Ang II) concentration of plasma had no significance (p > 0.05), but JCP significantly inhibited the Ang II concentration in RVHs’ kidney (p < 0.05). The kidney should be the target site of JCP. PMID:22412809

The Occurrence of Type S1A Serine Proteases in Sponge and Jellyfish

NASA Technical Reports Server (NTRS)

Rojas, Ana; Doolittle, Russell F.

2003-01-01

Although serine proteases are found in all kinds of cellular organisms and many viruses, the classic "chymotrypsin family" (Group S1A by th e 1998 Barrett nomenclature) has an unusual phylogenetic distribution , being especially common in animals, entirely absent from plants and protists, and rare among fungi. The distribution in Bacteria is larg ely restricted to the genus Streptomyces, although a few isolated occ urrences in other bacteria have been reported. The family may be enti rely absent from Archaea. Although more than a thousand sequences have been reported for enzymes of this type from animals, none of them ha ve been from early diverging phyla like Porifera or Cnidaria, We now report the existence of Group SlA serine proteases in a sponge (phylu m Porifera) and a jellyfish (phylum Cnidaria), making it safe to conc lude that all animal groups possess these enzymes.

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

First Report of a Thioredoxin Homologue in Jellyfish: Molecular Cloning, Expression and Antioxidant Activity of CcTrx1 from Cyanea capillata

PubMed Central

Zhou, Yonghong; Wang, Qianqian; Chang, Yinlong; Wang, Beilei; Zheng, Jiemin; Zhang, Liming

2014-01-01

Thioredoxins (Trx proteins) are a family of small, highly-conserved and ubiquitous proteins that play significant roles in the resistance of oxidative damage. In this study, a homologue of Trx was identified from the cDNA library of tentacle of the jellyfish Cyanea capillata and named CcTrx1. The full-length cDNA of CcTrx1 was 479 bp with a 312 bp open reading frame encoding 104 amino acids. Bioinformatics analysis revealed that the putative CcTrx1 protein harbored the evolutionarily-conserved Trx active site 31CGPC34 and shared a high similarity with Trx1 proteins from other organisms analyzed, indicating that CcTrx1 is a new member of Trx1 sub-family. CcTrx1 mRNA was found to be constitutively expressed in tentacle, umbrella, oral arm and gonad, indicating a general role of CcTrx1 protein in various physiological processes. The recombinant CcTrx1 (rCcTrx1) protein was expressed in Escherichia coli BL21 (DE3), and then purified by affinity chromatography. The rCcTrx1 protein was demonstrated to possess the expected redox activity in enzymatic analysis and protection against oxidative damage of supercoiled DNA. These results indicate that CcTrx1 may function as an important antioxidant in C. capillata. To our knowledge, this is the first Trx protein characterized from jellyfish species. PMID:24824597

Livermore time-sharing system. Part I. Octopus. Chapter 5. Card reader/card punch. [Description of card reader and formats

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lawrence, J.D.

1970-03-12

The Control Data 405 card reader, modified by the Control Data 3649 card read controller, is the primary mechanism for transferring information from a deck of punched cards into the CDC 6600 and CDC 7600 computers of the LLL Octopus system. The card reader operates at a maximum rate of 1200 cards per minute. A description of the card reader and its operation is given. A discussion of formates is included. (RWR)

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.