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Sample records for jellyfish chironex fleckeri

  1. Chironex fleckeri (Box Jellyfish) Venom Proteins

    PubMed Central

    Brinkman, Diane L.; Konstantakopoulos, Nicki; McInerney, Bernie V.; Mulvenna, Jason; Seymour, Jamie E.; Isbister, Geoffrey K.; Hodgson, Wayne C.

    2014-01-01

    The box jellyfish Chironex fleckeri produces extremely potent and rapid-acting venom that is harmful to humans and lethal to prey. Here, we describe the characterization of two C. fleckeri venom proteins, CfTX-A (∼40 kDa) and CfTX-B (∼42 kDa), which were isolated from C. fleckeri venom using size exclusion chromatography and cation exchange chromatography. Full-length cDNA sequences encoding CfTX-A and -B and a third putative toxin, CfTX-Bt, were subsequently retrieved from a C. fleckeri tentacle cDNA library. Bioinformatic analyses revealed that the new toxins belong to a small family of potent cnidarian pore-forming toxins that includes two other C. fleckeri toxins, CfTX-1 and CfTX-2. Phylogenetic inferences from amino acid sequences of the toxin family grouped CfTX-A, -B, and -Bt in a separate clade from CfTX-1 and -2, suggesting that the C. fleckeri toxins have diversified structurally and functionally during evolution. Comparative bioactivity assays revealed that CfTX-1/2 (25 μg kg−1) caused profound effects on the cardiovascular system of anesthetized rats, whereas CfTX-A/B elicited only minor effects at the same dose. Conversely, the hemolytic activity of CfTX-A/B (HU50 = 5 ng ml−1) was at least 30 times greater than that of CfTX-1/2. Structural homology between the cubozoan toxins and insecticidal three-domain Cry toxins (δ-endotoxins) suggests that the toxins have a similar pore-forming mechanism of action involving α-helices of the N-terminal domain, whereas structural diversification among toxin members may modulate target specificity. Expansion of the cnidarian toxin family therefore provides new insights into the evolutionary diversification of box jellyfish toxins from a structural and functional perspective. PMID:24403082

  2. Growth, Development and Temporal Variation in the Onset of Six Chironex fleckeri Medusae Seasons: A Contribution to Understanding Jellyfish Ecology

    PubMed Central

    Gordon, Matthew; Seymour, Jamie

    2012-01-01

    Despite the worldwide distribution, toxicity and commercial, industrial and medical impacts jellyfish present, many aspects of their ecology remain poorly understood. Quantified here are important ecological parameters of Chironex fleckeri medusae, contributing not only to the understanding of an understudied taxon, the cubozoa, but also to the broader understanding of jellyfish ecology. C. fleckeri medusae were collected across seven seasons (1999, 2000, 2003, 2005–07 and 2010), with growth rates, temporal variation in the medusae season onset and differences in population structure between estuarine and coastal habitats quantified. With a mean of 2 September ±2 d (mean ±95% confidence limits), the earliest date of metamorphosis was temporally constrained between seasons, varying by only 7 d (30 August to 5 September). Juvenile medusae appeared to be added over an extended period, suggesting polyp metamorphosis was an ongoing process once it commenced. At a maximum of 3±0.2 mm d−1 IPD, medusae growth to an asymptotic size of ∼190 mm IPD was rapid, yet, with the oldest medusae estimated to be ∼78 d in age, medusae did not appear to accumulate along the coastline. Furthermore, a greater proportion of juveniles were observed along the coastline, with estuarine populations typified by larger medusae. With key aspects of C. fleckeri's ecology now quantified, medusae season management protocols can be further developed. PMID:22384009

  3. 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

  4. Preliminary observations on the response of Chironex fleckeri (Cnidaria: Cubozoa: Chirodropida) to different colors of light.

    PubMed

    Gershwin, Lisa-Ann; Dawes, Peter

    2008-08-01

    Cubozoans are well known for their attraction to light and light-colored objects. Two highly venomous types are a public safety concern in Australian waters and elsewhere: Chironex fleckeri, long considered the world's deadliest animal and colloquially called the box jellyfish; and the irukandjis, a group of at least 10 species that cause various degrees of debilitating illness. We were asked by the tourism industry whether there might be a color of light that box jellyfish and irukandjis are not attracted to, such that nighttime diving activities might pose less risk of being stung. Our preliminary trials with Chironex fleckeri indicated a marked positive response to lights of white, red, yellow, green, orange, and blue. All colors elicited a strong and directed attraction to light; however, medusae slowed down their pulsation rate, streamed out their tentacles, and performed a series of figure-eight patterns back and forth through the lighted area when exposed to blue light, which we interpreted as feeding behavior. This compares curiously with a report subsequent to our testing, in which the small, mangrove-inhabiting cubomedusa Tripedalia cystophora and the beach-dwelling Chiropsella bronzie demonstrate a peak sensitivity to blue-green light in the region of 500 nm, and that the former is behaviorally attracted to blue and green light, but ignores red. This leaves open the possibility that Irukandji species, which are more closely related to Tripedalia than to Chironex, may be blind to red. PMID:18723637

  5. Comparative study of the toxic effects of Chrysaora quinquecirrha (Cnidaria: Scyphozoa) and Chironex fleckeri (Cnidaria: Cubozoa) venoms using cell-based assays.

    PubMed

    Ponce, Dalia; Brinkman, Diane L; Luna-Ramírez, Karen; Wright, Christine E; Dorantes-Aranda, Juan José

    2015-11-01

    The venoms of jellyfish cause toxic effects in diverse biological systems that can trigger local and systemic reactions. In this study, the cytotoxic and cytolytic effects of Chrysaora quinquecirrha and Chironex fleckeri venoms were assessed and compared using three in vitro assays. Venoms from both species were cytotoxic to fish gill cells and rat cardiomyocytes, and cytolytic in sheep erythrocytes. Both venoms decreased cell viability in a concentration-dependent manner; however, the greatest difference in venom potencies was observed in the fish gill cell line, wherein C. fleckeri was 12.2- (P = 0.0005) and 35.7-fold (P < 0.0001) more potently cytotoxic than C. quinquecirrha venom with 30 min and 120 min cell exposure periods, respectively. Gill cells and rat cardiomyocytes exposed to venoms showed morphological changes characterised by cell shrinkage, clumping and detachment. The cytotoxic effects of venoms may be caused by a group of toxic proteins that have been previously identified in C. fleckeri and other cubozoan jellyfish species. In this study, proteins homologous to CfTX-1 and CfTX-2 toxins from C. fleckeri and CqTX-A toxin from Chironex yamaguchii were identified in C. quinquecirrha venom using tandem mass spectrometry. The presence and relative abundance of these proteins may explain the differences in venom potency between cubozoan and scyphozoan jellyfish and may reflect their importance in the action of venoms. PMID:26385314

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

    PubMed Central

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

    2016-01-01

    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 km2. 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. PMID:26924604

  7. 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

    2016-01-01

    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. PMID:26924604

  8. 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

  9. Variation in lethality and effects of two Australian chirodropid jellyfish venoms in fish.

    PubMed

    Kintner, Anna H; Seymour, Jamie E; Edwards, Susan L

    2005-11-01

    The North Queensland chirodropid box jellyfish Chironex fleckeri and Chiropsalmus sp. share similar nematocyst composition and the same prey of Acetes australis shrimps in their early medusa stages; however, as C. fleckeri individuals reach larger size, the animals add fish to their diet and their complement of nematocyst types changes, allowing larger doses of venom to be delivered to prey. This study demonstrated that the venoms of the two species differ as well: despite similar effects previously documented in crustacean prey models, the two had widely different cardiac and lethal effects in fish, with C. fleckeri being substantially more potent in its ability to cause death. Comparisons between the venom delivery abilities of the two species showed that the change in nematocysts of C. fleckeri cannot alone account for its ontogenetic shift to prey fish; instead, its prey ecology clearly necessitates it having venom capable of acting efficiently to cause death in fish. Although this venom is almost certainly produced at greater metabolic cost to the animal than the less-lethal venom of Chiropsalmus sp., owing to its greater molecular protein complexity, it confers the advantage of increased caloric intake from fish prey, facilitating larger size and potentially greater reproductive output of C. fleckeri over Chiropsalmus sp. PMID:16165181

  10. First record of association of copepods with highly venomous box jellyfish Chironex, with description of new species of Paramacrochiron (Cyclopoida: Macrochironidae).

    PubMed

    Ohtsuka, Susumu; Metillo, Ephrime; Boxshall, Geoffrey A

    2015-04-01

    Paramacrochiron chironecicola n. sp. (Copepoda: Cyclopoida: Macrochironidae) is described from the highly venomous box jellyfish Chironex sp. collected from Malampaya Sound, Palawan Island, The Philippines. This is the first record of copepods associated with cubozoan medusae, although other cnidarian groups such scyphozoans, hydrozoans, and anthozoans are common hosts for symbiotic copepods. The infection sites were on the subumbrella, pedalium, and rhopalium, but also rarely on the adradial furrow. The new species is distinguished from other congeners by a combination of the following features: (1) the fifth pedigerous somite dorsally covering the anterior part of the female genital double-somite; (2) the fine structures of the antenna (relative lengths of segments) and maxilliped (positions of terminal elements) of the female; (3) the relatively long outer spines on the exopodal segments of legs 1-4; (4) the relatively long and thick female leg 5 bearing a long protopodal seta which reaches to the distal margin of the exopod; (5) the relatively short caudal ramus in the female; and (6) the plump prosome and short urosome in the male. Since members of the genus typically parasitize scyphozoans, especially rhizostomes, the association of this parasitic copepod on cubozoans may reflect the relatively close phylogenetic relationship between cubozoans and scyphozoans. PMID:25826070

  11. Length Is Associated with Pain: Jellyfish with Painful Sting Have Longer Nematocyst Tubules than Harmless Jellyfish.

    PubMed

    Kitatani, Ryuju; Yamada, Mayu; Kamio, Michiya; Nagai, Hiroshi

    2015-01-01

    A large number of humans are stung by jellyfish all over the world. The stings cause acute pain followed by persistent pain and local inflammation. Harmful jellyfish species typically cause strong pain, whereas harmless jellyfish cause subtle or no pain. Jellyfish sting humans by injecting a tubule, contained in the nematocyst, the stinging organ of jellyfish. The tubule penetrates into the skin leading to venom injection. The detailed morphology of the nematocyst tubule and molecular structure of the venom in the nematocyst has been reported; however, the mechanism responsible for the difference in pain that is caused by harmful and harmless jellyfish sting has not yet been explored or explained. Therefore, we hypothesized that differences in the length of the nematocyst tubule leads to different degrees of epithelial damage. The initial acute pain might be generated by penetration of the tubule, which stimulates pain receptor neurons, whilst persistent pain might be caused by injection of venom into the epithelium. To test this hypothesis we compared the lengths of discharged nematocyst tubules from harmful and harmless jellyfish species and evaluated their ability to penetrate human skin. The results showed that the harmful jellyfish species, Chrysaora pacifica, Carybdea brevipedalia, and Chironex yamaguchii, causing moderate to severe pain, have nematocyst tubules longer than 200 μm, compared with a jellyfish species that cause little or no pain, Aurelia aurita. The majority of the tubules of harmful jellyfishes, C. yamaguchii and C. brevipedalia, were sufficiently long to penetrate the human epidermis and physically stimulate the free nerve endings of Aδ pain receptor fibers around plexuses to cause acute pain and inject the venom into the human skin epithelium to cause persistent pain and inflammation. PMID:26309256

  12. Length Is Associated with Pain: Jellyfish with Painful Sting Have Longer Nematocyst Tubules than Harmless Jellyfish

    PubMed Central

    Kitatani, Ryuju; Yamada, Mayu; Kamio, Michiya; Nagai, Hiroshi

    2015-01-01

    A large number of humans are stung by jellyfish all over the world. The stings cause acute pain followed by persistent pain and local inflammation. Harmful jellyfish species typically cause strong pain, whereas harmless jellyfish cause subtle or no pain. Jellyfish sting humans by injecting a tubule, contained in the nematocyst, the stinging organ of jellyfish. The tubule penetrates into the skin leading to venom injection. The detailed morphology of the nematocyst tubule and molecular structure of the venom in the nematocyst has been reported; however, the mechanism responsible for the difference in pain that is caused by harmful and harmless jellyfish sting has not yet been explored or explained. Therefore, we hypothesized that differences in the length of the nematocyst tubule leads to different degrees of epithelial damage. The initial acute pain might be generated by penetration of the tubule, which stimulates pain receptor neurons, whilst persistent pain might be caused by injection of venom into the epithelium. To test this hypothesis we compared the lengths of discharged nematocyst tubules from harmful and harmless jellyfish species and evaluated their ability to penetrate human skin. The results showed that the harmful jellyfish species, Chrysaora pacifica, Carybdea brevipedalia, and Chironex yamaguchii, causing moderate to severe pain, have nematocyst tubules longer than 200 μm, compared with a jellyfish species that cause little or no pain, Aurelia aurita. The majority of the tubules of harmful jellyfishes, C. yamaguchii and C. brevipedalia, were sufficiently long to penetrate the human epidermis and physically stimulate the free nerve endings of Aδ pain receptor fibers around plexuses to cause acute pain and inject the venom into the human skin epithelium to cause persistent pain and inflammation. PMID:26309256

  13. Jellyfish stings

    MedlinePlus

    ... extending from each corner. There are over 40 species of box jellies. These range from nearly invisible ... jellyfish are highly dangerous, and more than 8 species have caused deaths. Box jellyfish are found in ...

  14. More on that jellyfish

    NASA Astrophysics Data System (ADS)

    Pataky, Lucky; edprochack

    2014-03-01

    This jellyfish-like flying machine (built by Leif Ristroph and Stephen Childress of New York University) can hover and stabilize itself in flight with no feedback control ("Flying 'jellyfish' is self-stabilizing", 16 January http://ow.ly/tl63X; see also p5).

  15. Kinematics and Fluid Dynamics of Jellyfish Maneuvering

    NASA Astrophysics Data System (ADS)

    Miller, Laura; Hoover, Alex

    2014-11-01

    Jellyfish propel themselves through the water through periodic contractions of their elastic bells. Some jellyfish, such as the moon jellyfish Aurelia aurita and the upside down jellyfish Cassiopea xamachana, can perform turns via asymmetric contractions of the bell. The fluid dynamics of jellyfish forward propulsion and turning is explored here by analyzing the contraction kinematics of several species and using flow visualization to quantify the resulting flow fields. The asymmetric contraction and structure of the jellyfish generates asymmetries in the starting and stopping vortices. This creates a diagonal jet and a net torque acting on the jellyfish. Results are compared to immersed boundary simulations

  16. 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. PMID:12807313

  17. Immunostimulation effect of jellyfish collagen.

    PubMed

    Sugahara, Takuya; Ueno, Masashi; Goto, Yoko; Shiraishi, Ryusuke; Doi, Mikiharu; Akiyama, Koichi; Yamauchi, Satoshi

    2006-09-01

    Certain edible large jellyfishes belonging to the order Rhizostomeae are consumed in large quantities in China and Japan. The exumbrella part of the edible jellyfish Stomolophus nomurai was cut and soaked in dilute hydrochloric acid solution (pH 3.0) for 12 h, and heated at 121 degrees C for 20 min. The immunostimulation effects of the jellyfish extract were examined. The jellyfish extract enhanced IgM production of human hybridoma HB4C5 cells 34-fold. IgM and IgG production of human peripheral blood lymphocytes (PBL) were also accelerated, 2.8- and 1.4-fold respectively. Moreover, production of interferon (IFN)-gamma and tumor necrosis factor (TNF)-alpha by human PBL was stimulated 100- and 17-fold respectively. Collagenase treatment inactivated the immunostimulation activity of the jellyfish extract. In addition, purified collagen from bovine Achilles' tendon accelerated IgM production of hybridoma cells. These facts mean that collagen has an immunostimulation effect, and that the active substance in jellyfish extract is collagen. PMID:16960386

  18. Social behaviour in mesopelagic jellyfish.

    PubMed

    Kaartvedt, Stein; Ugland, Karl I; Klevjer, Thor A; Røstad, Anders; Titelman, Josefin; Solberg, Ingrid

    2015-01-01

    Gelatinous organisms apparently play a central role in deep pelagic ecosystems, but lack of observational methodologies has restricted information on their behaviour. We made acoustic records of diel migrating jellyfish Periphylla periphylla forming small, ephemeral groups at the upper fringe of an acoustic scattering layer consisting of krill. Groups of P. periphylla were also documented photographically using a remotely operated vehicle (ROV). Although the adaptive value of group formation remains speculative, we clearly demonstrate the ability of these jellyfishes to locate and team up with each other. PMID:26065904

  19. Social behaviour in mesopelagic jellyfish

    NASA Astrophysics Data System (ADS)

    Kaartvedt, Stein; Ugland, Karl I.; Klevjer, Thor A.; Røstad, Anders; Titelman, Josefin; Solberg, Ingrid

    2015-06-01

    Gelatinous organisms apparently play a central role in deep pelagic ecosystems, but lack of observational methodologies has restricted information on their behaviour. We made acoustic records of diel migrating jellyfish Periphylla periphylla forming small, ephemeral groups at the upper fringe of an acoustic scattering layer consisting of krill. Groups of P. periphylla were also documented photographically using a remotely operated vehicle (ROV). Although the adaptive value of group formation remains speculative, we clearly demonstrate the ability of these jellyfishes to locate and team up with each other.

  20. Social behaviour in mesopelagic jellyfish

    PubMed Central

    Kaartvedt, Stein; Ugland, Karl I.; Klevjer, Thor A.; Røstad, Anders; Titelman, Josefin; Solberg, Ingrid

    2015-01-01

    Gelatinous organisms apparently play a central role in deep pelagic ecosystems, but lack of observational methodologies has restricted information on their behaviour. We made acoustic records of diel migrating jellyfish Periphylla periphylla forming small, ephemeral groups at the upper fringe of an acoustic scattering layer consisting of krill. Groups of P. periphylla were also documented photographically using a remotely operated vehicle (ROV). Although the adaptive value of group formation remains speculative, we clearly demonstrate the ability of these jellyfishes to locate and team up with each other. PMID:26065904

  1. [Dermatotoxicity of the Adriatic jellyfish].

    PubMed

    Kokelj, F; Stinco, G; Del Negro, P

    1990-12-01

    We have tested the dermatotoxicity of some purified nematocysts preparations of Aurelia aurita, Chrysaora hysoscella, Rhizostoma pulmo, in 25 volunteers by means of scratch-patch test. Our results show the validity of the method used for nematocyst purification. The few skin reactions obtained confirm the low dermototoxicity of the jellyfish studied. PMID:2091981

  2. Jellyfish inspired underwater unmanned vehicle

    NASA Astrophysics Data System (ADS)

    Villanueva, Alex; Bresser, Scott; Chung, Sanghun; Tadesse, Yonas; Priya, Shashank

    2009-03-01

    An unmanned underwater vehicle (UUV) was designed inspired by the form and functionality of a Jellyfish. These natural organisms were chosen as bio-inspiration for a multitude of reasons including: efficiency of locomotion, lack of natural predators, proper form and shape to incorporate payload, and varying range of sizes. The structure consists of a hub body surrounded by bell segments and microcontroller based drive system. The locomotion of UUV was achieved by shape memory alloy "Biometal Fiber" actuation which possesses large strain and blocking force with adequate response time. The main criterion in design of UUV was the use of low-profile shape memory alloy actuators which act as artificial muscles. In this manuscript, we discuss the design of two Jellyfish prototypes and present experimental results illustrating the performance and power consumption.

  3. Dangerous jellyfish blooms are predictable

    PubMed Central

    Gershwin, Lisa-ann; Condie, Scott A.; Mansbridge, Jim V.; Richardson, Anthony J.

    2014-01-01

    The potentially fatal Irukandji syndrome is relatively common in tropical waters throughout the world. It is caused by the sting of the Irukandji jellyfish, a family of box jellyfish that are almost impossible to detect in the water owing to their small size and transparency. Using collated medical records of stings and local weather conditions, we show that the presence of Irukandji blooms in coastal waters can be forecast on the basis of wind conditions. On the Great Barrier Reef, blooms largely coincide with relaxation of the prevailing southeasterly trade winds, with average conditions corresponding to near zero alongshore wind on the day prior to the sting. These conditions are consistent with hypotheses long held by local communities and provide a basis for designing management interventions that have the potential to eliminate the majority of stings. PMID:24829278

  4. Jellyfish Stings: A Practical Approach.

    PubMed

    Lakkis, Najla A; Maalouf, Grace J; Mahmassani, Dina M

    2015-09-01

    Jellyfish have a worldwide distribution. Their stings can cause different reactions, ranging from cutaneous, localized, and self-limited to serious systemic or fatal ones, depending on the envenoming species. Several first aid treatments are used to manage such stings but few have evidence behind their use. This review of the literature describes and discusses the different related first aid and treatment recommendations, ending with a summarized practical approach. Further randomized controlled trials in this field are needed. PMID:25935311

  5. Heat Beats Cold for Treating Jellyfish Stings

    MedlinePlus

    ... page: https://medlineplus.gov/news/fullstory_158584.html Heat Beats Cold for Treating Jellyfish Stings Evidence favors hot water or hot packs to ease pain ... 29, 2016 (HealthDay News) -- If you're unlucky enough to suffer a jellyfish sting, new research says that heat is better than cold for easing the pain. ...

  6. The jellyfish buffet: jellyfish enhance seabird foraging opportunities by concentrating prey.

    PubMed

    Sato, Nobuhiko N; Kokubun, Nobuo; Yamamoto, Takashi; Watanuki, Yutaka; Kitaysky, Alexander S; Takahashi, Akinori

    2015-08-01

    High levels of jellyfish biomass have been reported in marine ecosystems around the world, but understanding of their ecological role remains in its infancy. Jellyfish are generally thought to have indirect negative impacts on higher trophic-level predators, through changes in lower trophic pathways. However, high densities of jellyfish in the water column may affect the foraging behaviour of marine predators more directly, and the effects may not always be negative. Here, we present novel observations of a diving seabird, the thick-billed murre, feeding on fish aggregating among the long tentacles of large jellyfish, by using small video loggers attached to the birds. We show that the birds encountered large jellyfish, Chrysaora melanaster, during most of their dives, commonly fed on fish associated with jellyfish, and appeared to specifically target jellyfish with a high number of fish aggregating in their tentacles, suggesting the use of jellyfish may provide significant energetic benefits to foraging murres. We conclude that jellyfish provide feeding opportunities for diving seabirds by concentrating forage fish, and that the impacts of jellyfish on marine ecosystems are more complex than previously anticipated and may be beneficial to seabirds. PMID:26311157

  7. Jellyfish modulate bacterial dynamic and community structure.

    PubMed

    Tinta, Tinkara; Kogovšek, Tjaša; Malej, Alenka; Turk, Valentina

    2012-01-01

    Jellyfish blooms have increased in coastal areas around the world and the outbreaks have become longer and more frequent over the past few decades. The Mediterranean Sea is among the heavily affected regions and the common bloom-forming taxa are scyphozoans Aurelia aurita s.l., Pelagia noctiluca, and Rhizostoma pulmo. Jellyfish have few natural predators, therefore their carcasses at the termination of a bloom represent an organic-rich substrate that supports rapid bacterial growth, and may have a large impact on the surrounding environment. The focus of this study was to explore whether jellyfish substrate have an impact on bacterial community phylotype selection. We conducted in situ jellyfish-enrichment experiment with three different jellyfish species. Bacterial dynamic together with nutrients were monitored to assess decaying jellyfish-bacteria dynamics. Our results show that jellyfish biomass is characterized by protein rich organic matter, which is highly bioavailable to 'jellyfish-associated' and 'free-living' bacteria, and triggers rapid shifts in bacterial population dynamics and composition. Based on 16S rRNA clone libraries and denaturing gradient gel electrophoresis (DGGE) analysis, we observed a rapid shift in community composition from unculturable Alphaproteobacteria to culturable species of Gammaproteobacteria and Flavobacteria. The results of sequence analyses of bacterial isolates and of total bacterial community determined by culture independent genetic analysis showed the dominance of the Pseudoalteromonadaceae and the Vibrionaceae families. Elevated levels of dissolved proteins, dissolved organic and inorganic nutrient release, bacterial abundance and carbon production as well as ammonium concentrations characterized the degradation process. The biochemical composition of jellyfish species may influence changes in the amount of accumulated dissolved organic and inorganic nutrients. Our results can contribute insights into possible changes in

  8. Jellyfish Modulate Bacterial Dynamic and Community Structure

    PubMed Central

    Tinta, Tinkara; Kogovšek, Tjaša; Malej, Alenka; Turk, Valentina

    2012-01-01

    Jellyfish blooms have increased in coastal areas around the world and the outbreaks have become longer and more frequent over the past few decades. The Mediterranean Sea is among the heavily affected regions and the common bloom - forming taxa are scyphozoans Aurelia aurita s.l., Pelagia noctiluca, and Rhizostoma pulmo. Jellyfish have few natural predators, therefore their carcasses at the termination of a bloom represent an organic-rich substrate that supports rapid bacterial growth, and may have a large impact on the surrounding environment. The focus of this study was to explore whether jellyfish substrate have an impact on bacterial community phylotype selection. We conducted in situ jellyfish - enrichment experiment with three different jellyfish species. Bacterial dynamic together with nutrients were monitored to assess decaying jellyfish-bacteria dynamics. Our results show that jellyfish biomass is characterized by protein rich organic matter, which is highly bioavailable to ‘jellyfish - associated’ and ‘free - living’ bacteria, and triggers rapid shifts in bacterial population dynamics and composition. Based on 16S rRNA clone libraries and denaturing gradient gel electrophoresis (DGGE) analysis, we observed a rapid shift in community composition from unculturable Alphaproteobacteria to culturable species of Gammaproteobacteria and Flavobacteria. The results of sequence analyses of bacterial isolates and of total bacterial community determined by culture independent genetic analysis showed the dominance of the Pseudoalteromonadaceae and the Vibrionaceae families. Elevated levels of dissolved proteins, dissolved organic and inorganic nutrient release, bacterial abundance and carbon production as well as ammonium concentrations characterized the degradation process. The biochemical composition of jellyfish species may influence changes in the amount of accumulated dissolved organic and inorganic nutrients. Our results can contribute insights into

  9. Cubozoan Venom-Induced Cardiovascular Collapse Is Caused by Hyperkalemia and Prevented by Zinc Gluconate in Mice

    PubMed Central

    Yanagihara, Angel A.; Shohet, Ralph V.

    2012-01-01

    Chironex fleckeri (Australian box jellyfish) stings can cause acute cardiovascular collapse and death. We developed methods to recover venom with high specific activity, and evaluated the effects of both total venom and constituent porins at doses equivalent to lethal envenomation. Marked potassium release occurred within 5 min and hemolysis within 20 min in human red blood cells (RBC) exposed to venom or purified venom porin. Electron microscopy revealed abundant ∼12-nm transmembrane pores in RBC exposed to purified venom porins. C57BL/6 mice injected with venom showed rapid decline in ejection fraction with progression to electromechanical dissociation and electrocardiographic findings consistent with acute hyperkalemia. Recognizing that porin assembly can be inhibited by zinc, we found that zinc gluconate inhibited potassium efflux from RBC exposed to total venom or purified porin, and prolonged survival time in mice following venom injection. These findings suggest that hyperkalemia is the critical event following Chironex fleckeri envenomation and that rapid administration of zinc could be life saving in human sting victims. PMID:23251508

  10. Exceptionally Preserved Jellyfishes from the Middle Cambrian

    PubMed Central

    Cartwright, Paulyn; Halgedahl, Susan L.; Hendricks, Jonathan R.; Jarrard, Richard D.; Marques, Antonio C.; Collins, Allen G.; Lieberman, Bruce S.

    2007-01-01

    Cnidarians represent an early diverging animal group and thus insight into their origin and diversification is key to understanding metazoan evolution. Further, cnidarian jellyfish comprise an important component of modern marine planktonic ecosystems. Here we report on exceptionally preserved cnidarian jellyfish fossils from the Middle Cambrian (∼505 million years old) Marjum Formation of Utah. These are the first described Cambrian jellyfish fossils to display exquisite preservation of soft part anatomy including detailed features of structures interpreted as trailing tentacles and subumbrellar and exumbrellar surfaces. If the interpretation of these preserved characters is correct, their presence is diagnostic of modern jellyfish taxa. These new discoveries may provide insight into the scope of cnidarian diversity shortly after the Cambrian radiation, and would reinforce the notion that important taxonomic components of the modern planktonic realm were in place by the Cambrian period. PMID:17971881

  11. Exceptionally preserved jellyfishes from the Middle Cambrian.

    PubMed

    Cartwright, Paulyn; Halgedahl, Susan L; Hendricks, Jonathan R; Jarrard, Richard D; Marques, Antonio C; Collins, Allen G; Lieberman, Bruce S

    2007-01-01

    Cnidarians represent an early diverging animal group and thus insight into their origin and diversification is key to understanding metazoan evolution. Further, cnidarian jellyfish comprise an important component of modern marine planktonic ecosystems. Here we report on exceptionally preserved cnidarian jellyfish fossils from the Middle Cambrian (approximately 505 million years old) Marjum Formation of Utah. These are the first described Cambrian jellyfish fossils to display exquisite preservation of soft part anatomy including detailed features of structures interpreted as trailing tentacles and subumbrellar and exumbrellar surfaces. If the interpretation of these preserved characters is correct, their presence is diagnostic of modern jellyfish taxa. These new discoveries may provide insight into the scope of cnidarian diversity shortly after the Cambrian radiation, and would reinforce the notion that important taxonomic components of the modern planktonic realm were in place by the Cambrian period. PMID:17971881

  12. 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.

  13. Optimal hash arrangement of tentacles in jellyfish.

    PubMed

    Okabe, Takuya; Yoshimura, Jin

    2016-01-01

    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. PMID:27273762

  14. Optimal hash arrangement of tentacles in jellyfish

    PubMed Central

    Okabe, Takuya; Yoshimura, Jin

    2016-01-01

    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. PMID:27273762

  15. Fluid dynamics of forward swimming and turning for jellyfish

    NASA Astrophysics Data System (ADS)

    Miller, Laura

    2012-11-01

    Jellyfish propel themselves through the water through periodic contractions of their elastic bells. Some jellyfish, such as the box jellyfish Tripedalia cystophora and the upside down jellyfish Cassiopea xamachana, can perform turns via asymmetric contractions of the bell and by generating asymmetries in the outflow opening of the bell. The fluid dynamics of jellyfish forward propulsion and turning is explored here using the immersed boundary method. The 2D and 3D Navier-Stokes equations are coupled to the motion of a simplified jellyfish represented by an elastic boundary. An adaptive and parallelized version of the immersed boundary method (IBAMR) is used to resolve the detailed structure of the vortex wake. The asymmetric contraction and structure of the jellyfish generates asymmetries in the starting and stopping vortices. This creates a diagonal jet and a net torque acting on the jellyfish.

  16. 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. PMID:27358374

  17. 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. PMID:23277544

  18. 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

  19. [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

  20. Studies on the serologic response to jellyfish envenomation.

    PubMed

    Burnett, J W; Cobbs, C S; Kelman, S N; Calton, G J

    1983-08-01

    The case histories of three patients with unusual reactions to jellyfish envenomations or increased amounts of anti-jellyfish serum antibodies are presented. These cases demonstrated the following facts: (1) Allergic reactions may play a significant pathophysiologic role in jellyfish envenomation of humans. (2) Elevated specific anti-jellyfish immunoglobulins may persist for several years. (3) Recurrence of the clinical cutaneous reaction to jellyfish stings may occur within a few weeks without additional contact with the tentacles. (4) It is apparent that serologic cross-reactivity between the sea nettle and the man-of-war occur, as do false-positive enzyme-linked immunosorbent assay (ELISA) serologic tests to either jellyfish venom. PMID:6136534

  1. 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. PMID:26883926

  2. Study on the carry capacity of edible jellyfish fishery in Liaodong Bay

    NASA Astrophysics Data System (ADS)

    You, Kui; Bian, Yongning; Ma, Caihua; Chi, Xupeng; Liu, Zhiqiang; Zhang, Yuyu

    2016-06-01

    Jellyfish fishing is a special type of fishery that mainly exists in some countries of East and Southeast Asia. China has the largest jellyfish fishery yield in the world with an annual harvest of around 300 thousand tons. Liaodong Bay is the most important jellyfish fishery ground in China. However, due to the high benefits of jellyfish fishery, which leads to illegal and out-of-season jellyfish fishing occurring each year in Liaodong Bay. Illegal jellyfish fishery in Liaodong Bay is a typical example of the tragedy of the commons. The key problem is that fishermen seek to an illegally initiate jellyfish fishing as early as possible. In this paper, basing on the data of edible jellyfish's biology and ecology, we mainly analyzed the history of jellyfish fishery in China, especially in Liaodong bay, and then we calculated the carry capacity of edible jellyfish in Liaodong Bay which is about 300 thousand tons one year. This number is equal to the recent annual yield of edible jellyfish in China. Furthermore, basing on the carry capacity and reasonable quotas price analysis, we set up a Jellyfish fishing quotas and deficit quotas buyback system which could be a suitable and effective solution for jellyfish fishery management and development in Liaodong Bay at the underlying roots. Although China is the first country with edible jellyfish aquaculture, the annual yield of jellyfish aquaculture is only one fifth of jellyfish fishing. So, there is a very bright developing prospect about edible jellyfish aquaculture in China.

  3. 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

  4. 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

  5. Jellyfish stings and their management: a review.

    PubMed

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

    2013-02-01

    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

  6. Do resonating bells increase jellyfish swimming performance?

    NASA Astrophysics Data System (ADS)

    Hoover, Alexander; Miller, Laura

    2013-11-01

    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 and/or more efficiently when the bell is driven at its resonant frequency. Previous work has modeled the jellyfish bell as a damped harmonic oscillator, and this simplified model suggests that work done by the bell is maximized when force is applied at the resonant frequency of the bell. We extend the idea of resonance phenomena of the jellyfish bell to a fluid structure interaction framework using the immersed boundary method. We first examine the effects of the bending stiffness of the bell on its resonant frequency. We then further our model with the inclusion of a ``muscular'' spring that connects the two sides of a 2D bell and drives it near its resonant frequency. We use this muscular spring to force the bell at varying frequencies and examine the work done by these springs and the resulting swimming speed. We finally augment our model with a flexible, passive bell margin to examine its role in propulsive efficiency.

  7. 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

  8. 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

  9. Mechanical and scaling considerations for efficient jellyfish swimming

    NASA Astrophysics Data System (ADS)

    Hoover, Alexander; Miller, Laura; Griffith, Boyce

    2015-11-01

    With a fossil record dating over half a billion years, jellyfish represent one of the earliest examples of how multicellular organisms first organized into moving systems. Lacking an agonist-antagonist muscle pairing, jellyfish swim via a process of elastic deformation and recoil. Jellyfish propulsion is generated via the coordinated contraction of its elastic bell by its coronal swimming muscles and a complementary re-expansion that is passively driven by stored elastic energy. Recent studies have found jellyfish to be one of the most efficient swimmers due to its low energy expenditure in their forward movement. Using an immersed boundary framework, we will further examine the efficiency of jellyfish swimming by incorporating material models that are informed by the musculature present in jellyfish into a model of the elastic jellyfish bell in three dimensions. The fully-coupled fluid structure interaction problem is solved using an adaptive and parallelized version of the immersed boundary method (IBAMR). This model is then used to explore how variability in the mechanical properties of the bell affect the work done by the bell as well as the cost of transport related to jellyfish locomotion. We then examine how the efficiency of this system is affected by the Reynolds number.

  10. Occurrence of organo-arsenicals in jellyfishes and their mucus.

    PubMed

    Hanaoka, K; Ohno, H; Wada, N; Ueno, S; Goessler, W; Kuehnelt, D; Schlagenhaufen, C; Kaise, T; Irgolic, K J

    2001-08-01

    Water-soluble arsenic compound fractions were extracted from seven species of jellyfishes and subjected to analysis by high-performance liquid chromatography-inductively coupled plasma mass spectrometry (HPLC-ICP-MS) for arsenicals. A low content of arsenic was found to be the characteristic of jellyfish. Arsenobetaine (AB) was the major arsenic compound without exception in the tissues of the jellyfish species and mucus-blobs collected from some of them. Although the arsenic content in Beroe cucumis, which preys on Bolinopsis mikado, was more than 13 times that in B. mikado, the chromatograms of these two species were similar in the distribution pattern of arsenicals. The nine species of jellyfishes including two species treated in the previous paper can be classified into arsenocholine (AC)-rich and AC-poor species. Jellyfishes belonging to Semaostamae were classified as AC-rich species. PMID:11482664

  11. 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.

  12. Evolution and functional diversity of jellyfish opsins.

    PubMed

    Suga, Hiroshi; Schmid, Volker; Gehring, Walter J

    2008-01-01

    Cnidaria are the most basal animal phylum possessing complex eyes [1]. Their eyes predominantly use ciliary photoreceptor cells (c-PRCs) like vertebrates, whereas insect eyes use rhabdomeric photoreceptor cells (r-PRCs) [1-4]. These two cell types show not only different cytoarchitectures but distinct phototransduction cascades, which are triggered by the respective types of opsins (e.g., [5]), ciliary opsins (c-opsins) and rhabdomeric opsins (r-opsins) [6]. Recent reports suggested that the c- and r-PRCs and their respective opsins diverged at least before the deuterostome-protostome split [7-9]. To study the earlier evolution of animal PRCs and opsins, we investigated two hydrozoan jellyfishes. We report here the first-characterized cnidarian opsins. Molecular phylogeny revealed that the cloned 20 jellyfish opsins, together with all the opsins from a hydra and some from a sea anemone, are more closely related to the c-opsins than to any other major opsin subfamily, indicating that the divergence of c- and r-opsins antedates the Cnidaria-Bilateria split. Possible scenarios of animal PRC evolution are discussed. Furthermore, Cladonema opsins show several distinct tissue- and stage-specific expression patterns. The expression of specific opsins in the eyes suggests a role in vision, whereas that in the gonads suggests a role in light-controlled release of gametes. PMID:18160295

  13. Passive mechanics in jellyfish-like locomotion

    NASA Astrophysics Data System (ADS)

    Wilson, Megan; Eldredge, Jeff

    2008-11-01

    The aim of this work is to identify possible benefits of passive flexibility in biologically-inspired locomotion. Substantial energy savings are likely achieved in natural locomotion by allowing a mix of actively controlled and passively responsive deformation. The jellyfish is a useful target of study, due to its relatively simple structure and the availability of recent kinematics and flow-field measurements. In this investigation, the jellyfish consists of a two-dimensional articulated system of rigid bodies linked by hinges. The kinematics -- expressed via the hinge angles -- are adapted from experimentally measured motion. The free swimming system is explored via high-fidelity numerical simulation with a viscous vortex particle method with coupled body dynamics. The computational tool allows the arbitrary designation of individual hinges as ``active'' or ``passive,'' to introduce a mix of flexibility into the system. In some cases, replacing an active hinge with a passive spring can enhance the mean swimming speed, thus reducing the power requirements of the system. Varying the stiffness and damping coefficients of the spring yield different locomotive results. The numerical solution is used to compute the finite-time Lyapunov exponents (FTLE) throughout the field. The FTLE fields reveal manifolds in the flow that act as transport barriers, uncovering otherwise unseen geometric characteristics of the flow field that add new insight into the locomotion mechanics.

  14. Jellyfish blooms in China: Dominant species, causes and consequences.

    PubMed

    Dong, Zhijun; Liu, Dongyan; Keesing, John K

    2010-07-01

    Three jellyfish species, Aurelia aurita, Cyanea nozakii and Nemopilema nomurai, form large blooms in Chinese seas. We report on the distribution and increasing incidence of jellyfish blooms and their consequences in Chinese coastal seas and analyze their relationship to anthropogenically derived changes to the environment in order to determine the possible causes. A. aurita, C. nozakii and N. nomurai form blooms in the temperate Chinese seas including the northern East China Sea, Yellow Sea and Bohai Sea. N. nomurai forms offshore blooms while the other two species bloom mainly in inshore areas. Eutrophication, overfishing, habitat modification for aquaculture and climate change are all possible contributory factors facilitating plausible mechanisms for the proliferation of jellyfish blooms. In the absence of improvement in coastal marine ecosystem health, jellyfish blooms could be sustained and may even spread from the locations in which they now occur. PMID:20553695

  15. A fluid mechanical model for current-generating-feeding jellyfish

    NASA Astrophysics Data System (ADS)

    Peng, Jifeng; Dabiri, John

    2008-11-01

    Many jellyfish species, e.g. moon jellyfish Aurelia aurita, use body motion to generate fluid currents which carry their prey to the vicinity of their capture appendages. In this study, a model was developed to understand the fluid mechanics for this current-generating-feeding mode of jellyfish. The flow generated by free-swimming Aurelia aurita was measured using digital particle image velocimetry. The dynamics of prey (e.g., brine shrimp Artemia) in the flow field were described by a modified Maxey-Riley equation which takes into consideration the inertia of prey and the escape forces, which prey exert in the presence of predator. A Lagrangian analysis was used to identify the region of the flow in which prey can be captured by the jellyfish and the clearance rate was quantified. The study provides a new methodology to study biological current-generating-feeding and the transport and mixing of particles in fluid flow in general.

  16. Scyphozoan jellyfish venom metalloproteinases and their role in the cytotoxicity.

    PubMed

    Lee, Hyunkyoung; Jung, Eun-sun; Kang, Changkeun; Yoon, Won Duk; Kim, Jong-Shu; Kim, Euikyung

    2011-09-01

    The present study, for the first time, comparatively investigated the enzymatic activities (proteases and hyaluronidases) in the venoms of four Scyphozoan jellyfish species, including Nemopilema nomurai, Rhopilema esculenta, Cyanea nozakii, and Aurelia aurita. For this, various zymographic analyses were performed using assay specific substrates. Interestingly, all the four jellyfish venoms showed gelatinolytic, caseinolytic, and fibrinolytic activities, each of which contains a multitude of enzyme components with molecular weights between 17 and 130 kDa. These four jellyfish venoms demonstrated a huge variation in their proteolytic activities in quantitative and qualitative manner depending on the species. Most of these enzymatic activities were disappeared by the treatment of 1,10-phenanthroline, suggesting they might be belonged to metalloproteinases. Toxicological significance of these venom proteases was examined by comparing their proteolytic activity and the cytotoxicity in NIH 3T3 cells. The relative cytotoxic potency was C. nozakii > N. nomurai > A. aurita > R. esculenta. The cytotoxicity of jellyfish venom shows a positive correlation with its overall proteolytic activity. The metalloproteinases appear to play an important role in the induction of jellyfish venom toxicities. In conclusion, the present report proposes a novel finding of Scyphozoan jellyfish venom metalloproteinases and their potential role in the cytotoxicity. PMID:21718715

  17. Muscular Control of Turning and Maneuvering in Jellyfish Bells

    NASA Astrophysics Data System (ADS)

    Hoover, Alexander; Miller, Laura; Griffith, Boyce

    2014-11-01

    Jellyfish represent one of the earliest and simplest examples of swimming by a macroscopic organism. Contractions of an elastic bell that expels water are driven by coronal swimming muscles. The re-expansion of the bell is passively driven by stored elastic energy. A current question in jellyfish propulsion is how the underlying neuromuscular organization of their bell allows for maneuvering. Using an immersed boundary framework, we will examine the mechanics of swimming by incorporating material models that are informed by the musculature present in jellyfish into a model of the elastic jellyfish bell in three dimensions. The fully-coupled fluid structure interaction problem is solved using an adaptive and parallelized version of the immersed boundary method (IBAMR). We then use this model to understand how variability in the muscular activation patterns allows for complicated swimming behavior, such as steering. We will compare the results of the simulations with the actual turning maneuvers of several species of jellyfish. Numerical flow fields will also be compared to those produced by actual jellyfish using particle image velocimetry (PIV).

  18. 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. PMID:10688264

  19. Jellyfish Galaxy Candidates at Low Redshift

    NASA Astrophysics Data System (ADS)

    Poggianti, B. M.; Fasano, G.; Omizzolo, A.; Gullieuszik, M.; Bettoni, D.; Moretti, A.; Paccagnella, A.; Jaffé, Y. L.; Vulcani, B.; Fritz, J.; Couch, W.; D'Onofrio, M.

    2016-03-01

    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 structures 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 LX. Interestingly, convincing cases of candidates are also found in groups and lower mass halos (1011-1014M⊙), although the physical mechanism at work needs to be securely identified. All the candidates are disky, have stellar masses ranging from log M/M⊙ < 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.

  20. 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.

  1. 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.

  2. 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. PMID:27436284

  3. Identification of genetically and oceanographically distinct blooms of jellyfish

    PubMed Central

    Lee, Patricia L. M.; Dawson, Michael N; Neill, Simon P.; Robins, Peter E.; Houghton, Jonathan D. R.; Doyle, Thomas K.; Hays, Graeme C.

    2013-01-01

    Reports of nuisance jellyfish blooms have increased worldwide during the last half-century, but the possible causes remain unclear. A persistent difficulty lies in identifying whether blooms occur owing to local or regional processes. This issue can be resolved, in part, by establishing the geographical scales of connectivity among locations, which may be addressed using genetic analyses and oceanographic modelling. We used landscape genetics and Lagrangian modelling of oceanographic dispersal to explore patterns of connectivity in the scyphozoan jellyfish Rhizostoma octopus, which occurs en masse at locations in the Irish Sea and northeastern Atlantic. We found significant genetic structure distinguishing three populations, with both consistencies and inconsistencies with prevailing physical oceanographic patterns. Our analyses identify locations where blooms occur in apparently geographically isolated populations, locations where blooms may be the source or result of migrants, and a location where blooms do not occur consistently and jellyfish are mostly immigrant. Our interdisciplinary approach thus provides a means to ascertain the geographical origins of jellyfish in outbreaks, which may have wide utility as increased international efforts investigate jellyfish blooms. PMID:23287405

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

    PubMed

    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

  5. 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. PMID:23916371

  6. 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

  7. 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.

  8. GFP: from jellyfish to the Nobel prize and beyond.

    PubMed

    Zimmer, Marc

    2009-10-01

    On December 10, 2008 Osamu Shimomura, Martin Chalfie and Roger Tsien were awarded the Nobel Prize in Chemistry for "the discovery and development of the green fluorescent protein, GFP". The path taken by this jellyfish protein to become one of the most useful tools in modern science and medicine is described. Osamu Shimomura painstakingly isolated GFP from hundreds of thousands of jellyfish, characterized the chromophore and elucidated the mechanism of Aequorean bioluminescence. Martin Chalfie expressed the protein in E. coli and C. elegans, and Roger Tsien developed a palette of fluorescent proteins that could be used in a myriad of applications. PMID:19771329

  9. Jellyfish Bioactive Compounds: Methods for Wet-Lab Work.

    PubMed

    Frazão, Bárbara; Antunes, Agostinho

    2016-04-01

    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

  10. 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

  11. Simulation of prolate swimming jellyfish with jet-based locomotion

    NASA Astrophysics Data System (ADS)

    Park, Sung Goon; Kim, Boyoung; Lee, Jin; Huang, Wei-Xi; Sung, Hyung Jin

    2014-11-01

    The hydrodynamic patterns in the wake of swimming jellyfish are based on the bell morphology. Jellyfish with a prolate bell morphology form a clear jet structure in the wake. A three-dimensional computational model was used to analyze the hydrodynamic patterns. The Froude propulsion efficiency, defined by the ratio of the value of the energy required to deform the elastic bell to the value of the average center velocity multiplied by the thrust, was compared with different forms of the elastic bell deformation. The immersed boundary method was adopted to consider the interaction between the swimming jellyfish and surrounding fluid. Due to the effect of the momentum transferred to the surrounding fluid by the bell deformation, the rotational fluid mass was formed, called vortices. The vortex structures in the wake of prolate swimming jellyfish were elucidated in detail in both quantitative and qualitative ways. A dimensionless temporal parameter was employed to investigate the vortex formation process quantitatively. The starting/stopping vortex structures were generated during the contraction/relaxation phase. During the early stage of the contraction, the vortex structures were mainly generated by the stroke, then the ejected fluid was entrained into the vortex structures. This study was supported by the Creative Research Initiatives (No.2014-001493) program of the National Research Foundation of Korea (MSIP).

  12. Biogeochemical implications of decomposing jellyfish blooms in a changing climate

    NASA Astrophysics Data System (ADS)

    Chelsky, Ariella; Pitt, Kylie A.; Welsh, David T.

    2015-03-01

    Jellyfish often exhibit 'boom and bust' population dynamics whereby they proliferate rapidly and then die en masse and decompose. The few studies that have investigated post-bloom processes have not studied how changing ocean conditions will alter rates of decomposition. Climate change will result in warmer and more acidic waters, and studies therefore need to consider these factors in concert to determine their combined effect on decomposition processes. To quantify the effect, we measured oxygen consumption and nutrient regeneration rates during decomposition of Catostylus mosaicus in mesocosms at current average summer pH and temperature (pH 8.0 and 27 °C) as well as conditions projected for year 2100 (pH 7.8 and 30 °C) and compared these fluxes to control mesocosms without jellyfish over 12 days. We hypothesised that rates of jellyfish decomposition, as measured by oxygen demand and nutrient regeneration, would be accelerated in the end-of-century treatments, compared to present day treatments. Overall decomposition rates were only slightly elevated under end-of-century conditions, and the difference was only significant for ammonium fluxes from 19 h until 43 h after the experiment commenced. The difference between treatments was much smaller than would be expected due to the temperature increase, based on theoretical modelling of jellyfish decomposition which predicts a Q10 of 4.28, or a 1.5 fold increase in decomposition rates. This highlights the importance of investigating net effects on decomposition rates, as simultaneous shifts in temperature and pH may not follow patterns predicted due to one stressor alone. Ultimately, these results suggest that rates of oxygen consumption and nutrient regeneration resulting from collapsed jellyfish blooms may not change drastically over the next 100 years.

  13. 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. PMID:26088540

  14. Anticoagulant activity of Moon jellyfish (Aurelia aurita) tentacle extract.

    PubMed

    Rastogi, Akriti; Biswas, Sumit; Sarkar, Angshuman; Chakrabarty, Dibakar

    2012-10-01

    Moon jellyfish (Aurelia aurita) tentacle extract was studied for its anticoagulant activity in vitro. The Jellyfish Tentacle Extract (JFTE) showed very strong fibrinogenolytic activity by cleaving Aα and Bβ chain of fibrinogen molecule. The fibrinogenolytic activity was found to be stronger than some snake venom derived anticoagulants. JFTE also completely liquefied fibrin clots in 24 h. JFTE was found to contain both high and low molecular weight proteins/peptides. The fibrinogenolysis appears to be caused by high molecular weight fractions of the extract. It has been also noted that PMSF significantly reduced fibrinogenolytic activity and heating totally abolished it. Autolytic degradation of the high molecular weight protein was also noted. Autolysis slowed down, but did not abolish the fibrinogenolytic activity of the extract. PMID:22652129

  15. High time resolution luminosity profiles of Jellyfish (Super) Sprites

    NASA Astrophysics Data System (ADS)

    McHarg, M. G.; Ahrns, J.; Stenbaek-Nielsen, H. C.; Kammae, T.; Haaland, R. K.; Cummer, S. A.; Li, J.; Liu, N.; Yukman, P.

    2011-12-01

    We compare the time history of luminosity and VLF measurements associated with different classes of sprites. In particular we are interested in the larger "jellyfish, or super" sprites that are very bright, very brief duration sprites. Optical observations reveal these sprites are collections of multiple carrot sprites, comprised of both downward and upward propagating streamers. We find the time scales of super sprites are shorter than that for carrot sprites and column sprites. The exponential decrease in sprite luminosity has been related to the conductivity profile assumed for the middle atmosphere by [Barrington-Leigh et. al. (2002), doi: 10.1029/2001JA900117]. We investigate the possibility that the overall brighter and rapid decrease in jellyfish sprite luminosity compared to other types of sprites may be related to changes in the middle atmosphere conductivity, and/or in the driving electrostatic field associated with the causative lightning flash.

  16. Biomass of Scyphozoan Jellyfish, and Its Spatial Association with 0-Group Fish in the Barents Sea

    PubMed Central

    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. PMID:22457732

  17. Reduction of a larval herring population by jellyfish predator.

    PubMed

    Möller, H

    1984-05-11

    The scyphomedusa Aurelia aurita consumes large amounts of yolk-sac herring larvae in Kiel Fjord. The decline of the larval herring population in late spring coincides with a major population growth of the jellyfish. The size of the larval herring population seems to be more significantly affected by the size of the predator stock than by the size of the parental herring stock. PMID:17838355

  18. Modeling and control of a jellyfish-inspired AUV

    NASA Astrophysics Data System (ADS)

    Faria, Cassio T.; Priya, Shashank; Inman, Daniel J.

    2013-04-01

    Current autonomous underwater vehicle (AUV) designs have a serious deficiency in autonomy time due to its ballistic type of construction: a cylindrical body propelled by a rear engine. This type of design does not take complete advantage of the fluid that has to be displaced to move the vehicle forward, reducing the overall system efficiency and consequently its operation time. In order to overcome this limitation, research has focused on understanding of the propulsive mechanisms employed by the natural organisms. Jellyfish is one of the simplest and most relevant model systems as it exhibits one of the lowest cost-of-transport among all the known creatures. The learning and implementation of jellyfish-inspired vehicle design requires an evaluation of the current mathematical modeling approaches in order to adequately describe the dynamics of such a vehicle. This paper develops a time-varying rigid body model for the kinematics and dynamics of an AUV based on jellyfish rowing propulsion. A nonlinear sliding mode controller is also proposed to drive the system.

  19. 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

  20. Jellyfish monitoring on coastlines using remote piloted aircraft

    NASA Astrophysics Data System (ADS)

    Barrado, C.; Fuentes, J. A.; Salamí, E.; Royo, P.; Olariaga, A. D.; López, J.; Fuentes, V. L.; Gili, J. M.; Pastor, E.

    2014-03-01

    In the last 10 years the number of jellyfish shoals that reach the swimming area of the Mediterranean Sea are increasing constantly. The term "Jellyfish" refers to animals from different taxonomic groups but the Scyphomedusae are within the most significant one. Four species of Scyphomedusae are the most conspicuous ones inhabiting the studied area, the Barcelona metropolitan area. Jellyfish are usually found at the surface waters, forming big swarms. This feature makes possible to detect them remotely, using a visual camera and image processing algorithms. In this paper we present the characteristics of a remote piloted aircraft capable to perform monitoring flights during the whole summer season. The requirements of the aircraft are to be easy to operate, to be able to flight at low altitude (100 m) following the buoy line (200 m from the beach line) and to be save for other users of the seaside. The remote piloted aircraft will carry a vision system and a processing board able to obtain useful information on real-time.

  1. 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

  2. Self-repairing symmetry in jellyfish through mechanically driven reorganization.

    PubMed

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

    2015-06-30

    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

  3. The Bright Side of Gelatinous Blooms: Nutraceutical Value and Antioxidant Properties of Three Mediterranean Jellyfish (Scyphozoa).

    PubMed

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

    2015-08-01

    Jellyfish are recorded with increasing frequency and magnitude in many coastal areas and several species display biological features comparable to the most popular Asiatic edible jellyfish. The biochemical and antioxidant properties of wild gelatinous biomasses, in terms of nutritional and nutraceutical values, are still largely unexplored. In this paper, three of the most abundant and commonly recorded jellyfish species (Aurelia sp.1, Cotylorhiza tuberculata and Rhizostoma pulmo) in the Mediterranean Sea were subject to investigation. A sequential enzymatic hydrolysis of jellyfish proteins was set up by pepsin and collagenase treatments of jellyfish samples after aqueous or hydroalcoholic protein extraction. The content and composition of proteins, amino acids, phenolics, and fatty acids of the three species were recorded and compared. Protein content (mainly represented by collagen) up to 40% of jellyfish dry weight were found in two of the three jellyfish species (C. tuberculata and R. pulmo), whereas the presence of ω-3 and ω-6 polyunsaturated fatty acids (PUFAs) was significantly higher in the zooxanthellate jellyfish C. tuberculata only. Remarkable antioxidant ability was also recorded from both proteinaceous and non proteinaceous extracts and the hydrolyzed protein fractions in all the three species. The abundance of collagen, peptides and other bioactive molecules make these Mediterranean gelatinous biomasses a largely untapped source of natural compounds of nutraceutical, cosmeceutical and pharmacological interest. PMID:26230703

  4. CONTINUATION AND EXPANSION OF DOCKWATCH VOLUNTEER REPORTING SYSTEMS FOR NUISANCE AND INVASIVE JELLYFISH

    EPA Science Inventory

    Gather data, using a citizens' monitoring network to track jellyfish occurrence in the northern Gulf of Mexico. The dtat will be incorporated into the database that will establish better linkages between jellyfish, transport and bloom cycles. The project will also be used imp...

  5. Nucleotide sequences of 5S rRNAs from four jellyfishes.

    PubMed

    Hori, H; Ohama, T; Kumazaki, T; Osawa, S

    1982-11-25

    The nucleotide sequences of 5S rRNAs from four jellyfishes, Spirocodon saltatrix, Nemopsis dofleini, Aurelia aurita and Chrysaora quinquecirrha have been determined. The sequences are highly similar to each other. A fairly high similarity was also found between these jellyfishes and a sea anemone, Anthopleura japonica. PMID:6130512

  6. The Bright Side of Gelatinous Blooms: Nutraceutical Value and Antioxidant Properties of Three Mediterranean Jellyfish (Scyphozoa)

    PubMed Central

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

    2015-01-01

    Jellyfish are recorded with increasing frequency and magnitude in many coastal areas and several species display biological features comparable to the most popular Asiatic edible jellyfish. The biochemical and antioxidant properties of wild gelatinous biomasses, in terms of nutritional and nutraceutical values, are still largely unexplored. In this paper, three of the most abundant and commonly recorded jellyfish species (Aurelia sp.1, Cotylorhiza tuberculata and Rhizostoma pulmo) in the Mediterranean Sea were subject to investigation. A sequential enzymatic hydrolysis of jellyfish proteins was set up by pepsin and collagenase treatments of jellyfish samples after aqueous or hydroalcoholic protein extraction. The content and composition of proteins, amino acids, phenolics, and fatty acids of the three species were recorded and compared. Protein content (mainly represented by collagen) up to 40% of jellyfish dry weight were found in two of the three jellyfish species (C. tuberculata and R. pulmo), whereas the presence of ω-3 and ω-6 polyunsaturated fatty acids (PUFAs) was significantly higher in the zooxanthellate jellyfish C. tuberculata only. Remarkable antioxidant ability was also recorded from both proteinaceous and non proteinaceous extracts and the hydrolyzed protein fractions in all the three species. The abundance of collagen, peptides and other bioactive molecules make these Mediterranean gelatinous biomasses a largely untapped source of natural compounds of nutraceutical, cosmeceutical and pharmacological interest. PMID:26230703

  7. A biomimetic jellyfish robot based on ionic polymer metal composite actuators

    NASA Astrophysics Data System (ADS)

    Yeom, Sung-Weon; Oh, Il-Kwon

    2009-08-01

    A biomimetic jellyfish robot based on ionic polymer metal composite actuators was fabricated and activated to mimic real locomotive behavior with pulse and recovery processes. To imitate the curved shape of the jellyfish, a thermal treatment was applied to obtain a permanent initial deformation of a hemispherical form. The bio-inspired input signal was generated for mimicking real locomotion of the jellyfish. The vertical floating displacement and the thrust force of the biomimetic jellyfish robot under various input signals were measured and compared. The present results show that the bio-inspired electrical input signal with pulse-recovery process generates much higher floating velocity of the biomimetic jellyfish robot in comparison with pure sinusoidal excitations. The curved shape of the IPMC actuator through thermal treatments can be successfully applied to mimic the real biomimetic robots with smooth curves.

  8. 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

    2014-03-01

    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. PMID:24583831

  9. 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. PMID:26593577

  10. Impact of Stinging Jellyfish Proliferations along South Italian Coasts: Human Health Hazards, Treatment and Social Costs

    PubMed Central

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

    2014-01-01

    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. PMID:24583831

  11. Evaluation of the effects of various chemicals on discharge of and pain caused by jellyfish nematocysts.

    PubMed

    Birsa, Laura M; Verity, Peter G; Lee, Richard F

    2010-05-01

    Jellyfish tentacles in contact with human skin can produce pain swelling and redness. The pain is due to discharge of jellyfish nematocysts and associated toxins and discharge can be caused by a variety of mechanical and chemical stimuli. A series of tests were carried out with chemicals traditionally used to treat jellyfish stings e.g. acetic acid ammonia meat tenderizer baking soda and urea to determine if these chemicals stimulated or inhibited nematocyst discharge and if they brought relief to testers who were exposed to jellyfish tentacles. Chrysaora quinquecirrha (sea nettle) Chiropsalmus quadrumanus (sea wasp) and Physalia physalis (Portuguese man-of-war) were used in the study. It was found that many of the chemicals traditionally used to treat jellyfish stings stimulated nematocyst discharge and did not relieve the pain. However there was immediate relief when a common anesthetic lidocaine was sprayed on the skin of testers in contact with jellyfish tentacles. Initial exposure of tentacle suspensions to lidocaine prevented the nematocyst discharge by subsequent exposure to acetic acid ethanol ammonia or bromelain. Thus lidocaine in addition to acting as an anesthetic on skin in contact with jellyfish tentacles inhibited nematocyst discharge possibly by blocking sodium and/or calcium channels of the nematocytes. PMID:20116454

  12. 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. PMID:26485278

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

    PubMed Central

    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. PMID:26485278

  14. A tissue-engineered jellyfish with biomimetic propulsion.

    PubMed

    Nawroth, Janna C; Lee, Hyungsuk; Feinberg, Adam W; Ripplinger, Crystal M; McCain, Megan L; Grosberg, Anna; Dabiri, John O; Parker, Kevin Kit

    2012-08-01

    Reverse engineering of biological form and function requires hierarchical design over several orders of space and time. Recent advances in the mechanistic understanding of biosynthetic compound materials, computer-aided design approaches in molecular synthetic biology 4,5 and traditional soft robotics, and increasing aptitude in generating structural and chemical micro environments that promote cellular self-organization have enhanced the ability to recapitulate such hierarchical architecture in engineered biological systems. Here we combined these capabilities in a systematic design strategy to reverse engineer a muscular pump. We report the construction of a freely swimming jellyfish from chemically dissociated rat tissue and silicone polymer as a proof of concept. The constructs, termed 'medusoids', were designed with computer simulations and experiments to match key determinants of jellyfish propulsion and feeding performance by quantitatively mimicking structural design, stroke kinematics and animal-fluid interactions. The combination of the engineering design algorithm with quantitative benchmarks of physiological performance suggests that our strategy is broadly applicable to reverse engineering of muscular organs or simple life forms that pump to survive. PMID:22820316

  15. Cell Proliferation in Cubozoan Jellyfish Tripedalia cystophora and Alatina moseri

    PubMed Central

    Gurska, Daniela; Garm, Anders

    2014-01-01

    Cubozoans (box jellyfish) undergo remarkable body reorganization throughout their life cycle when, first, they metamorphose from swimming larvae to sessile polyps, and second, through the metamorphosis from sessile polyps to free swimming medusae. In the latter they develop complex structures like the central nervous system (CNS) and visual organs. In the present study several aspects of cell proliferation at different stages of the life cycle of the box jellyfish Tripedalia cystophora and Alatina moseri have been examined through in vivo labeling of cells in the synthetic phase (S phase) of the cell cycle. Proliferation zones were found in metamorphosing polyps, as well as in juvenile medusae, where both the rhopalia and pedalia have enhanced rates of proliferation. The results also indicate a rather fast cell turnover in the rhopalia including the rhopalial nervous system (RNS). Moreover, T. cystophora showed diurnal pattern of cell proliferation in certain body parts of the medusa, with higher proliferation rates at nighttime. This is true for two areas in close connection with the CNS: the stalk base and the rhopalia. PMID:25047715

  16. Velarium control and visual steering in box jellyfish.

    PubMed

    Petie, Ronald; Garm, Anders; Nilsson, Dan-Eric

    2013-04-01

    Directional swimming in the box jellyfish Tripedalia cystophora (cubozoa, cnidaria) is controlled by the shape of the velarium, which is a thin muscular sheet that forms the opening of the bell. It was unclear how different patterns of visual stimulation control directional swimming and that is the focus of this study. Jellyfish were tethered inside a small experimental tank, where the four vertical walls formed light panels. All four panels were lit at the start of an experiment. The shape of the opening in the velarium was recorded in response to switching off different combinations of panels. We found that under the experimental conditions the opening in the velarium assumed three distinct shapes during a swim contraction. The opening was (1) centred or it was off-centred and pocketed out either towards (2) a rhopalium or (3) a pedalium. The shape of the opening in the velarium followed the direction of the stimulus as long as the stimulus contained directional information. When the stimulus contained no directional information, the percentage of centred pulses increased and the shape of the off-centred pulses had a random orientation. Removing one rhopalium did not change the directional response of the animals, however, the number of centred pulses increased. When three rhopalia were removed, the percentage of centred pulses increased even further and the animals lost their ability to respond to directional information. PMID:23417442

  17. A tissue-engineered jellyfish with biomimetic propulsion

    PubMed Central

    Nawroth, Janna C; Lee, Hyungsuk; Feinberg, Adam W; Ripplinger, Crystal M; McCain, Megan L; Grosberg, Anna; Dabiri, John O; Parker, Kevin Kit

    2014-01-01

    Reverse engineering of biological form and function requires hierarchical design over several orders of space and time. Recent advances in the mechanistic understanding of biosynthetic compound materials1–3, computer-aided design approaches in molecular synthetic biology4,5 and traditional soft robotics6,7, and increasing aptitude in generating structural and chemical microenvironments that promote cellular self-organization8–10 have enhanced the ability to recapitulate such hierarchical architecture in engineered biological systems. Here we combined these capabilities in a systematic design strategy to reverse engineer a muscular pump. We report the construction of a freely swimming jellyfish from chemically dissociated rat tissue and silicone polymer as a proof of concept. The constructs, termed ‘medusoids’, were designed with computer simulations and experiments to match key determinants of jellyfish propulsion and feeding performance by quantitatively mimicking structural design, stroke kinematics and animal-fluid interactions. The combination of the engineering design algorithm with quantitative benchmarks of physiological performance suggests that our strategy is broadly applicable to reverse engineering of muscular organs or simple life forms that pump to survive. PMID:22820316

  18. A shift to parasitism in the jellyfish symbiont Symbiodinium microadriaticum

    PubMed Central

    Sachs, Joel L; Wilcox, Thomas P

    2005-01-01

    One of the outstanding and poorly understood examples of cooperation between species is found in corals, hydras and jellyfish that form symbioses with algae. These mutualistic algae are mostly acquired infectiously from the seawater and, according to models of virulence evolution, should be selected to parasitize their hosts. We altered algal transmission between jellyfish hosts in the laboratory to examine the potential for virulence evolution in this widespread symbiosis. In one experimental treatment, vertical transmission of algae (parent to offspring) selected for symbiont cooperation, because symbiont fitness was tied to host reproduction. In the other treatment, horizontal transmission (infectious spread) decoupled symbiont fitness from the host, potentially allowing parasitic symbionts to spread. Fitness estimates revealed a striking shift to parasitism in the horizontal treatment. The horizontally transmitted algae proliferated faster within hosts and had higher dispersal rates from hosts compared to the vertical treatment, while reducing host reproduction and growth. However, a trade-off was detected between harm caused to hosts and symbiont fitness. Virulence trade-offs have been modelled for pathogens and may be critical in stabilising ‘infectious’ symbioses. Our results demonstrate the dynamic nature of this symbiosis and illustrate the potential ease with which beneficial symbionts can evolve into parasites. PMID:16615208

  19. Box jellyfish envenomation: case report of effective lemon and oil emulsion treatment.

    PubMed

    Hamann, Carsten R; Hamann, Dathan; Richardson, Clare; Seeburger, Jack

    2014-04-01

    Box jellyfish are highly venomous and numerous possible treatments for envenomation have already been reported in the published literature. The hand of a 55-year-old scuba diver was stung in the Gulf of Guinea resulting in two crops of coalescing vesicles with intense pain and lymphadenopathy. Traditional therapies such as hot water, cold packs and acetic acid were ineffective. Symptoms were rapidly relieved after the application of a lemon-oil emulsion balm. Treatments for jellyfish envenomation generally aim to either denature the jellyfish venom or prevent the discharge of the venom. Lemon-oil emulsion therapy has not yet been reported in the published literature but may be an economical and novel treatment for box jellyfish envenomation. PMID:24334401

  20. The marine biologist--Bob Endean.

    PubMed

    Hawgood, Barbara J

    2006-12-01

    Bob Endean was a dedicated marine biologist with an extensive knowledge of coral reef communities in the Great Barrier Reef and fauna in subtropical Queensland waters. He commenced a study of venomous and poisonous marine animals dangerous to man at a time when the field was new, employing a variety of techniques to investigate the venom apparatus, mode of delivery of venom or toxin, mode of toxic action on excitable tissues, and biochemistry of venom or toxin. Determination of the pharmacological properties of crude venom from Conus marine snails advanced characterization of conotoxins by later workers. A study of four types of nematocysts from the box-jellyfish Chironex fleckeri provided information as to their structure, function, and mechanism of discharge; myotoxins T1 and T2 were isolated from microbasic mastigophores. Endean studied poisonous stonefish (Synanceia trachynis) and, with Ann Cameron, scorpionfish (Notesthes robusta); investigations of ciguatera and of paralytic shellfish poisoning were initiated. He organized the collection of Australian frogs which led to the isolation of caerulein by Erspamer in Italy. Endean highlighted the ecological danger of the population explosion of the crown-of-thorns starfish (Acanthaster planci) and provided the impetus for the creation of the Great Barrier Reef Marine Park. PMID:16952385

  1. 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. PMID:20453210

  2. Jellyfish blooms result in a major microbial respiratory sink of carbon in marine systems.

    PubMed

    Condon, Robert H; Steinberg, Deborah K; del Giorgio, Paul A; Bouvier, Thierry C; Bronk, Deborah A; Graham, William M; Ducklow, Hugh W

    2011-06-21

    Jellyfish blooms occur in many estuarine and coastal regions and may be increasing in their magnitude and extent worldwide. Voracious jellyfish predation impacts food webs by converting large quantities of carbon (C), fixed by primary producers and consumed by secondary producers, into gelatinous biomass, which restricts C transfer to higher trophic levels because jellyfish are not readily consumed by other predators. In addition, jellyfish release colloidal and dissolved organic matter (jelly-DOM), and could further influence the functioning of coastal systems by altering microbial nutrient and DOM pathways, yet the links between jellyfish and bacterioplankton metabolism and community structure are unknown. Here we report that jellyfish released substantial quantities of extremely labile C-rich DOM, relative to nitrogen (25.6 ± 31.6 C:1N), which was quickly metabolized by bacterioplankton at uptake rates two to six times that of bulk DOM pools. When jelly-DOM was consumed it was shunted toward bacterial respiration rather than production, significantly reducing bacterial growth efficiencies by 10% to 15%. Jelly-DOM also favored the rapid growth and dominance of specific bacterial phylogenetic groups (primarily γ-proteobacteria) that were rare in ambient waters, implying that jelly-DOM was channeled through a small component of the in situ microbial assemblage and thus induced large changes in community composition. Our findings suggest major shifts in microbial structure and function associated with jellyfish blooms, and a large detour of C toward bacterial CO(2) production and away from higher trophic levels. These results further suggest fundamental transformations in the biogeochemical functioning and biological structure of food webs associated with jellyfish blooms. PMID:21646531

  3. A Randomized, Controlled Field Trial for the Prevention of Jellyfish Stings With a Topical Sting Inhibitor

    PubMed Central

    Boulware, David R.

    2007-01-01

    Background Jellyfish stings are a common occurrence among ocean goers worldwide with an estimated 150 million envenomations annually. Fatalities and hospitalizations occur annually, particularly in the Indo-Pacific regions. A new topical jellyfish sting inhibitor based on the mucous coating of the clown fish prevents 85% of jellyfish stings in laboratory settings. The field effectiveness is unknown. The objective is to evaluate the field efficacy of the jellyfish sting inhibitor, Safe Sea™. Methods A double-blind, randomized, placebo-controlled trial occurred at the Dry Tortugas National Park, FL, USA and Sapodilla Cayes, Belize. Participants were healthy volunteers planning to snorkel for 30 to 45 minutes. Ten minutes prior to swimming, each participant was directly observed applying a blinded sample of Safe Sea (Nidaria Technology Ltd, Jordan Valley, Israel) to one side of their body and a blinded sample of Coppertone® (Schering-Plough, Kenilworth, NJ, USA) to the contralateral side as placebo control. Masked 26 g samples of both Safe Sea SPF15 and Coppertone® SPF15 were provided in identical containers to achieve 2 mg/cm2 coverage. Sides were randomly chosen by participants. The incidence of jellyfish stings was the main outcome measure. This was assessed by participant interview and examination as subjects exited the water. Results A total of 82 observed water exposures occurred. Thirteen jellyfish stings occurred during the study period for a 16% incidence. Eleven jellyfish stings occurred with placebo, two with the sting inhibitor, resulting in a relative risk reduction of 82% (95% confidence interval: 21%–96%; p = 0.02). No seabather’s eruption or side effects occurred. Conclusions Safe Sea is a topical barrier cream effective at preventing >80% jellyfish stings under real-world conditions. PMID:16706948

  4. Jellyfish-associated bacterial communities and bacterioplankton in Indonesian Marine lakes.

    PubMed

    Cleary, Daniel F R; Becking, Leontine E; Polónia, Ana R M; Freitas, Rossana M; Gomes, Newton C M

    2016-05-01

    In the present study, we compared communities of bacteria in two jellyfish species (the 'golden' jellyfishMastigiascf.papuaand the box jellyfishTripedaliacf.cystophora) and water in three marine lakes located in the Berau region of northeastern Borneo, Indonesia. Jellyfish-associated bacterial communities were compositionally distinct and less diverse than bacterioplankton communities. Alphaproteobacteria, Gammaproteobacteria, Synechococcophycidae and Flavobacteriia were the most abundant classes in water. Jellyfish-associated bacterial communities were dominated by OTUs assigned to the Gammaproteobacteria (family Endozoicimonaceae), Mollicutes, Spirochaetes and Alphaproteobacteria (orders Kiloniellales and Rhodobacterales). Mollicutes were mainly restricted toMastigiaswhereas Spirochaetes and the order Kiloniellales were most abundant inTripedaliahosts. The most abundant OTU overall in jellyfish hosts was assigned to the family Endozoicimonaceae and was highly similar to organisms in Genbank obtained from various hosts including an octocoral, bivalve and fish species. Other abundant OTUs included an OTU assigned to the order Entomoplasmatales and mainly found inMastigiashosts and OTUs assigned to the Spirochaetes and order Kiloniellales and mainly found inTripedaliahosts. The low sequence similarity of the Entomoplasmatales OTU to sequences in Genbank suggests that it may be a novel lineage inhabitingMastigiasand possibly restricted to marine lakes. PMID:27004797

  5. High activity and Lévy searches: jellyfish can search the water column like fish

    PubMed Central

    Hays, Graeme C.; Bastian, Thomas; Doyle, Thomas K.; Fossette, Sabrina; Gleiss, Adrian C.; Gravenor, Michael B.; Hobson, Victoria J.; Humphries, Nicolas E.; Lilley, Martin K. S.; Pade, Nicolas G.; Sims, David W.

    2012-01-01

    Over-fishing may lead to a decrease in fish abundance and a proliferation of jellyfish. Active movements and prey search might be thought to provide a competitive advantage for fish, but here we use data-loggers to show that the frequently occurring coastal jellyfish (Rhizostoma octopus) does not simply passively drift to encounter prey. Jellyfish (327 days of data from 25 jellyfish with depth collected every 1 min) showed very dynamic vertical movements, with their integrated vertical movement averaging 619.2 m d−1, more than 60 times the water depth where they were tagged. The majority of movement patterns were best approximated by exponential models describing normal random walks. However, jellyfish also showed switching behaviour from exponential patterns to patterns best fitted by a truncated Lévy distribution with exponents (mean μ = 1.96, range 1.2–2.9) close to the theoretical optimum for searching for sparse prey (μopt ≈ 2.0). Complex movements in these ‘simple’ animals may help jellyfish to compete effectively with fish for plankton prey, which may enhance their ability to increase in dominance in perturbed ocean systems. PMID:21752825

  6. Three-dimensional simulation of jellyfish by the penalty immersed boundary method

    NASA Astrophysics Data System (ADS)

    Park, Sung Goon; Chang, Cheng Bong; Sung, Hyung Jin; Flow Control Laboratory Team

    2012-11-01

    The interaction between the motion of a three-dimensional jellyfish and the surrounding fluid was numerically simulated by the penalty immersed boundary method (pIBM). The effects of the vortex formation and the elastic properties on the kinematics of swimming jellyfish were examined. In order to simulate the incompressible fluid motion, the fractional step method was adopted on the Eulerian domain, while the subdivision finite element method was used to describe the solid motion on the Lagrangian domain. Coupling of the fluid motion and the jellyfish motion was realized in the framework of the pIBM. Our results suggest that the starting and stopping vortices, which are respectively induced from a power stroke and a recovery stroke, were formed in the wake of the swimming jellyfish. These two types of vortex interacted with each other, which made the size of vortex larger and caused the augmentation of thrust. Swimming performance of the jellyfish also depended on the elastic properties such as the tension and bending rigidity. It was found that the center velocity of the jellyfish increases with increasing the tension rigidity.

  7. A jellyfish-like swimming mini-robot actuated by an electromagnetic actuation system

    NASA Astrophysics Data System (ADS)

    Ko, Youngho; Na, Sungyoung; Lee, Youngwoo; Cha, Kyoungrae; Ko, Seong Young; Park, Jongoh; Park, Sukho

    2012-05-01

    Among the various kinds of actuations for biomimetic robots, the electromagnetic actuation (EMA) method has been regarded as the one with the most potential. This paper proposes a jellyfish-like swimming mini-robot actuated by an EMA system in three-dimensional (3D) space. The jellyfish-like mini-robot has four flexible fins, each of which is equipped with a permanent magnet for electromagnetic actuation; the robot’s body is 17 mm long and 0.5 mm thick. Our EMA system was able to generate a uniform magnetic field in a desired direction in 3D space, which could bend the fins of the jellyfish-like mini-robot. Therefore, a cyclic change in the uniform magnetic field, in the EMA system, would synchronize the fluctuation of the fins and could generate a propulsion force for the robot, in the desired direction. In order to maximize the propulsion force of the jellyfish-like mini-robot, the waveform and frequency of the input current in the EMA system are optimized. Consequently, our jellyfish-like mini-robot was able to generate maximum propulsion force when a square waveform input current (13 A magnitude and 10 Hz frequency) was applied to the EMA system. Finally, the jellyfish-like mini-robot with the EMA system was able to perform various 3D swimming motions.

  8. 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

  9. Irukandji jellyfish polyps exhibit tolerance to interacting climate change stressors.

    PubMed

    Klein, Shannon G; Pitt, Kylie A; Rathjen, Kristen A; Seymour, Jamie E

    2014-01-01

    Increasing ocean temperatures and strengthening boundary currents have caused the poleward migration of many marine species. Cubozoan jellyfish known to cause Irukandji syndrome have historically been confined to tropical waters but may be expanding into subtropical regions. Here, we examine the interactive effects of warming and acidification on the population dynamics of polyps of an Irukandji jellyfish, Alatina nr mordens, and the formation of statoliths in newly metamorphosed medusae, to determine if this jellyfish could tolerate future conditions predicted for southeast Queensland (SEQ), Australia. Two experiments, examining the orthogonal factors of temperature and pH, were undertaken. Experiment 1 mimicked the current, ca. 2050 and ca. 2100 summer temperature and pH conditions predicted for SEQ using A1F1 scenarios (temperature: 25, 27, 29 °C; pH: 7.9, 7.8, 7.6) and Experiment 2 mimicked current and future winter conditions (18 and 22 °C, pH 7.9, 7.8, 7.6). All polyps in Experiment 1 survived and budded. Fewer polyps budded in the lower pH treatments; however, patterns varied slightly among temperature treatments. Statoliths at pH 7.6 were 24% narrower than those at pH 7.8 and 7.9. Most polyps survived the winter conditions mimicked by Experiment 2 but only polyps in the 22 °C, pH 7.9 treatment increased significantly. The current absence of A. nr mordens medusae in SEQ, despite the polyps' ability to tolerate the current temperature and pH conditions, suggests that ecological, rather than abiotic factors currently limit their distribution. Observations that budding was lower under low pH treatments suggest that rates of asexual reproduction will likely be much slower in the future. We consider that A. nr mordens polyps are likely to tolerate future conditions but are unlikely to thrive in the long term. However, if polyps can overcome potential ecological boundaries and acidification proceeds slowly A. nr mordens could expand polewards in the short

  10. 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. PMID:27285534

  11. An investigation of habituation in the jellyfish Aurelia aurita.

    PubMed

    Johnson, M C; Wuensch, K L

    1994-01-01

    Three experiments were conducted to examine the effectiveness of different forms of tactile stimulation, probe and stream, and interstimulus intervals (ISI) in producing habituation in the polypoid sessile stage of the jellyfish Aurelia aurita. Results from Experiment 1 showed that polyps significantly decreased their responsiveness to both forms of tactile stimulation with 30-s ISI across 60 trials. Response to a novel stimulus indicated that the response decrement had not been due to fatigue. When the ISI was lengthened to 6 min in Experiment 2, response to the probe form of tactile stimulation did not significantly decrease across 20 trials. Using an ISI of 1 min in Experiment 3, response to the probe form of tactile stimulation decreased significantly across 40 trials. A significant increase in response to the original stimulus (dishabituation) following presentation of a novel stimulus indicated that response decrement was due to habituation or a habituation-like process rather than simple effector fatigue or sensory adaptation. PMID:8129686

  12. 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.

  13. 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. PMID:24182899

  14. 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. PMID:26322863

  15. Hydrogen-fuel-powered bell segments of biomimetic jellyfish

    NASA Astrophysics Data System (ADS)

    Tadesse, Yonas; Villanueva, Alex; Haines, Carter; Novitski, David; Baughman, Ray; Priya, Shashank

    2012-04-01

    Artificial muscles powered by a renewable energy source are desired for joint articulation in bio-inspired autonomous systems. In this study, a robotic underwater vehicle, inspired by jellyfish, was designed to be actuated by a chemical fuel source. The fuel-powered muscles presented in this work comprise nano-platinum catalyst-coated multi-wall carbon nanotube (MWCNT) sheets, wrapped on the surface of nickel-titanium (NiTi) shape memory alloy (SMA). As a mixture of oxygen and hydrogen gases makes contact with the platinum, the resulting exothermic reaction activates the nickel-titanium (NiTi)-based SMA. The MWCNT sheets serve as a support for the platinum particles and enhance the heat transfer due to the high thermal conductivity between the composite and the SMA. A hydrogen and oxygen fuel source could potentially provide higher power density than electrical sources. Several vehicle designs were considered and a peripheral SMA configuration under the robotic bell was chosen as the best arrangement. Constitutive equations combined with thermodynamic modeling were developed to understand the influence of system parameters that affect the overall actuation behavior of the fuel-powered SMA. The model is based on the changes in entropy of the hydrogen and oxygen fuel on the composite actuator within a channel. The specific heat capacity is the dominant factor controlling the width of the strain for various pulse widths of fuel delivery. Both theoretical and experimental strains for different diameter (100 and 150 µm) SMA/MWCNT/Pt fuel-powered muscles with dead weight attached at the end exhibited the highest magnitude under 450 ms of fuel delivery within 1.6 mm diameter conduit size. Fuel-powered bell deformation of 13.5% was found to be comparable to that of electrically powered (29%) and natural jellyfish (42%).

  16. [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. PMID:27228622

  17. Isolation, Characterization and Biological Evaluation of Jellyfish Collagen for Use in Biomedical Applications

    PubMed Central

    Addad, Sourour; Exposito, Jean-Yves; Faye, Clément; Ricard-Blum, Sylvie; Lethias, Claire

    2011-01-01

    Fibrillar collagens are the more abundant extracellular proteins. They form a metazoan-specific family, and are highly conserved from sponge to human. Their structural and physiological properties have been successfully used in the food, cosmetic, and pharmaceutical industries. On the other hand, the increase of jellyfish has led us to consider this marine animal as a natural product for food and medicine. Here, we have tested different Mediterranean jellyfish species in order to investigate the economic potential of their collagens. We have studied different methods of collagen purification (tissues and experimental procedures). The best collagen yield was obtained using Rhizostoma pulmo oral arms and the pepsin extraction method (2–10 mg collagen/g of wet tissue). Although a significant yield was obtained with Cotylorhiza tuberculata (0.45 mg/g), R. pulmo was used for further experiments, this jellyfish being considered as harmless to humans and being an abundant source of material. Then, we compared the biological properties of R. pulmo collagen with mammalian fibrillar collagens in cell cytotoxicity assays and cell adhesion. There was no statistical difference in cytotoxicity (p > 0.05) between R. pulmo collagen and rat type I collagen. However, since heparin inhibits cell adhesion to jellyfish-native collagen by 55%, the main difference is that heparan sulfate proteoglycans could be preferentially involved in fibroblast and osteoblast adhesion to jellyfish collagens. Our data confirm the broad harmlessness of jellyfish collagens, and their biological effect on human cells that are similar to that of mammalian type I collagen. Given the bioavailability of jellyfish collagen and its biological properties, this marine material is thus a good candidate for replacing bovine or human collagens in selected biomedical applications. PMID:21747742

  18. Current-oriented swimming by jellyfish and its role in bloom maintenance.

    PubMed

    Fossette, Sabrina; Gleiss, Adrian Christopher; Chalumeau, Julien; Bastian, Thomas; Armstrong, Claire Denise; Vandenabeele, Sylvie; Karpytchev, Mikhail; Hays, Graeme Clive

    2015-02-01

    Cross-flows (winds or currents) affect animal movements [1-3]. Animals can temporarily be carried off course or permanently carried away from their preferred habitat by drift depending on their own traveling speed in relation to that of the flow [1]. Animals able to only weakly fly or swim will be the most impacted (e.g., [4]). To circumvent this problem, animals must be able to detect the effects of flow on their movements and respond to it [1, 2]. Here, we show that a weakly swimming organism, the jellyfish Rhizostoma octopus, can orientate its movements with respect to currents and that this behavior is key to the maintenance of blooms and essential to reduce the probability of stranding. We combined in situ observations with first-time deployment of accelerometers on free-ranging jellyfish and simulated the behavior observed in wild jellyfish within a high-resolution hydrodynamic model. Our results show that jellyfish can actively swim countercurrent in response to current drift, leading to significant life-history benefits, i.e., increased chance of survival and facilitated bloom formation. Current-oriented swimming may be achieved by jellyfish either directly detecting current shear across their body surface [5] or indirectly assessing drift direction using other cues (e.g., magnetic, infrasound). Our coupled behavioral-hydrodynamic model provides new evidence that current-oriented swimming contributes to jellyfish being able to form aggregations of hundreds to millions of individuals for up to several months, which may have substantial ecosystem and socioeconomic consequences [6, 7]. It also contributes to improve predictions of jellyfish blooms' magnitude and movements in coastal waters. PMID:25619761

  19. 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

  20. 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. PMID:27100175

  1. 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

  2. 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

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

    PubMed

    Hoover, Alexander; Miller, Laura

    2015-06-01

    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. PMID:25823642

  4. 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

  5. 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

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

    PubMed

    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

  7. 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

  8. Giant jellyfish Nemopilema nomurai gathering in the Yellow Sea—a numerical study

    NASA Astrophysics Data System (ADS)

    Wei, Hao; Deng, Lijing; Wang, Yuheng; Zhao, Liang; Li, Xia; Zhang, Fang

    2015-04-01

    A particle tracking model, based on output from the Princeton Ocean Model (POM), is established to study the year-to-year variation of the gathering of giant jellyfish Nemopilema nomurai in early autumn in the Yellow Sea. Particles standing for scyphistoma adhered to the bottom are put initially along the coast from the Changjiang River estuary to Haizhou Bay. The triggering temperature for scyphistoma strobilation is set to 13 °C. The simulated N. nomurai distribution is in good agreement with observations in August 2009. Model results suggest that more jellyfish gathered near tidal front in August-September of 2008 than during the same period of 2009. Using a set of sensitivity experiments, the influences of temperature and circulation on N. nomurai gathering are discussed. Model results suggest the modeled difference in fall gathering of jellyfish between 2008 and 2009 can be attributed more to changes in circulation than the triggering of strobilation by spring bottom temperature.

  9. Milbemycin oxime (Interceptor) treatment of amphipod parasites (Hyperiidae) from several host jellyfish species.

    PubMed

    Boonstra, Jennifer L; Koneval, Maureen E; Clark, James D; Schick, Mark; Smith, Malissa; Stark, Amy L

    2015-03-01

    Wild-caught crystal jellyfish (Aequorea victoria) arrived at the John G. Shedd Aquarium infested with hyperiid amphipods (Hyperia medusarum), which were inadvertently introduced into a system containing several jellyfish species. Affected systems were treated with milbemycin oxime (Interceptor tablets for dogs 51-100 lbs, Novartis Animal Health US, Inc., Greensboro, North Carolina 27408, USA), a treatment prescribed for red bug (Tegastes acroporanus) infestation in corals. Two treatments using one 25-mg aliquot of Interceptor per 10 gallons of tank water administered 6-7 days apart were completed. Overall, treatment to eradicate the parasite from the affected systems was successful. Further studies evaluating the tolerance of jellyfish to milbemycin oxime, particularly in small juvenile Eutonina indicans and Aurelia aurita, are warranted. Based on clinical observations, there were more negative effects associated with the treatment in the hydrozoans than in the scyphozoans. PMID:25831592

  10. 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. PMID:27068562

  11. The complete mitochondrial genome of the Antarctic stalked jellyfish, Haliclystus antarcticus Pfeffer, 1889 (Staurozoa: Stauromedusae).

    PubMed

    Li, Hsing-Hui; Sung, Ping-Jyun; Ho, Hsuan-Ching

    2016-06-01

    In present study, the complete mitogenome sequence of the Antarctic stalked jellyfish, Haliclystus antarcticus Pfeffer (Staurozoa: Stauromedusae) has been sequenced by next-generation sequencing method. The assembled mitogenome comprises of 15,766 bp including 13 protein coding genes, 7 transfer RNAs, and 2 ribosomal RNA genes. The overall base of Antarctic stalked jellyfish constitutes of 26.5% for A, 19.6% for C, 19.8% for G, 34.1% for T and show 90% identity to Sessile Jelly, Haliclystus sanjuanensis, in the northeastern Pacific Ocean. The complete mitogenome of the Antarctic stalked jellyfish, contributes fundamental and significant DNA molecular data for further phylogeography and evolutionary analysis for seahorse phylogeny. The complete sequence was deposited in DBBJ/EMBL/GenBank under accession number KU947038. PMID:27222813

  12. Changes in the small-jellyfish community in recent decades in Jiaozhou Bay, China

    NASA Astrophysics Data System (ADS)

    Sun, Song; Li, Yinghong; Sun, Xiaoxia

    2012-07-01

    We used long term monitoring data to evaluate changes in abundance and species dominance of small-jellyfish (collected with zooplankton net whose bell diameter was less than 5 cm) between 1991 and 2009 in the Jiaozhou Bay, China. Zooplankton samples were vertically towed with conical plankton net from near-bottom to surface, identified microscopically, and mapped in time-space using Grapher 7.0 and Surfer 8.0. Results show that the abundance of small-jellyfish throughout the bay had been increasing during 2001-2009 on average of 15.2 ind./m3, almost 5 times higher than that between 1991 and 2000. The occurrence of peak abundance shifted from spring to summer after 2000, and two peaks appeared in spring and summer, respectively, after 2005. Both the abundance and the frequency of blooms of small-jellyfish increased after 2000 in the bay. In addition, the biodiversity of jellyfish has increased significantly in recent years with a change in dominant species. Several new dominant species appeared after 2000, including Rathkae octopunctata in winter, Phialidium hemisphaericum in spring, summer, and autumn, Phialucium carolinae in spring, and Pleurobrachia globosa in summer and autumn, while some previous dominant species throughout the 1990s ( Eirene ceylonensis, Zanclea costata, Lovenella assimilis, and Muggiaea atlantica ) were no longer dominant after 2000. The abundance of small-jellyfish was positively correlated with the density of dinoflagellates, and the abundance of zooplankton. We believe that the changes in smalljellyfish abundance and species composition were the result of eutrophication, aquaculture and coastal construction activities around the bay. Concurrently, seawater warming and salinity decrease in recent decades promoted the growth and reproduction of small-jellyfish in the bay.

  13. 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

  14. Stable hovering of a jellyfish-like flying machine.

    PubMed

    Ristroph, Leif; Childress, Stephen

    2014-03-01

    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

  15. Statolith Morphometrics Can Discriminate among Taxa of Cubozoan Jellyfishes

    PubMed Central

    Kingsford, Michael J.

    2016-01-01

    Identification of potentially harmful cubomedusae is difficult due to their gelatinous nature. The only hard structure of medusae, the statolith, has the potential to provide robust measurements for morphometric analysis. Traditional morphometric length to width ratios (L: W) and modern morphometric Elliptical Fourier Analysis (EFA) were applied to proximal, oral and lateral statolith faces of 12 cubozoan species. EFA outperformed L: W as L: W did not account for the curvature of the statolith. Best discrimination was achieved with Canonical Discriminant Analysis (CDA) when analysing proximal + oral + lateral statolith faces in combination. Normalised Elliptical Fourier (NEF) coefficients classified 98% of samples to their correct species and 94% to family group. Statolith shape agreed with currently accepted cubozoan taxonomy. This has potential to assist in identifying levels of risk and stock structure of populations in areas where box jellyfish envenomations are a concern as the severity of envenomation is family dependent. We have only studied 12 (27%) of the 45 currently accepted cubomedusae, but analyses demonstrated that statolith shape is an effective taxonomic discriminator within the Class. PMID:27192408

  16. Statolith Morphometrics Can Discriminate among Taxa of Cubozoan Jellyfishes.

    PubMed

    Mooney, Christopher J; Kingsford, Michael J

    2016-01-01

    Identification of potentially harmful cubomedusae is difficult due to their gelatinous nature. The only hard structure of medusae, the statolith, has the potential to provide robust measurements for morphometric analysis. Traditional morphometric length to width ratios (L: W) and modern morphometric Elliptical Fourier Analysis (EFA) were applied to proximal, oral and lateral statolith faces of 12 cubozoan species. EFA outperformed L: W as L: W did not account for the curvature of the statolith. Best discrimination was achieved with Canonical Discriminant Analysis (CDA) when analysing proximal + oral + lateral statolith faces in combination. Normalised Elliptical Fourier (NEF) coefficients classified 98% of samples to their correct species and 94% to family group. Statolith shape agreed with currently accepted cubozoan taxonomy. This has potential to assist in identifying levels of risk and stock structure of populations in areas where box jellyfish envenomations are a concern as the severity of envenomation is family dependent. We have only studied 12 (27%) of the 45 currently accepted cubomedusae, but analyses demonstrated that statolith shape is an effective taxonomic discriminator within the Class. PMID:27192408

  17. Jellyfish Envenomation Presenting with Delayed Identical Cutaneous Lesions in a Mother and Child.

    PubMed

    Chakrabarti, Aditi; Sengupta, Sujata

    2015-01-01

    Jellyfish envenomation can present with local cutaneous lesions both immediate and delayed. While the immediate reaction is toxin mediated, an immune mechanism is responsible for the delayed eruptions. This is a report of a mother and child who developed identical papular lesions in a bizarre, linear distribution after coming in contact with jellyfish almost simultaneously while on holiday. Histology showed focal basal cell degeneration along with peri-vascular and peri-appendageal lympho-mononuclear infiltrate. Both patients responded well to topical tacrolimus. PMID:26538698

  18. Jellyfish Envenomation Presenting with Delayed Identical Cutaneous Lesions in a Mother and Child

    PubMed Central

    Chakrabarti, Aditi; Sengupta, Sujata

    2015-01-01

    Jellyfish envenomation can present with local cutaneous lesions both immediate and delayed. While the immediate reaction is toxin mediated, an immune mechanism is responsible for the delayed eruptions. This is a report of a mother and child who developed identical papular lesions in a bizarre, linear distribution after coming in contact with jellyfish almost simultaneously while on holiday. Histology showed focal basal cell degeneration along with peri-vascular and peri-appendageal lympho-mononuclear infiltrate. Both patients responded well to topical tacrolimus. PMID:26538698

  19. Recurrent dermatitis and dermal hypersensitivity following a jellyfish sting: a case report and review of literature.

    PubMed

    Loredana Asztalos, Manuela; Rubin, Adam I; Elenitsas, Rosalie; Groft MacFarlane, Caroline; Castelo-Soccio, Leslie

    2014-01-01

    Jellyfish envenomation often causes an immediate painful vesiculopapular eruption. Less commonly it can cause a type IV allergic hypersensitivity that manifests with delayed or recurrent cutaneous lesions at the primary site or distant from the primary site. These secondary reactivations may be related to high antijellyfish immunoglobulin levels, intracutaneously sequestered antigen, or cross-reacting venom. Immunomodulators such as pimecrolimus and tacrolimus and topical and intralesional corticosteroid therapy decrease this recurrent dermatitis. We report a case of a 9-year-old girl with a recurrent jellyfish dermatitis lasting more than 1 year after the initial envenomation. The dermatitis finally resolved after treatment with tacrolimus and intralesional triamcinolone acetonide therapy. PMID:24495001

  20. 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

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

    PubMed Central

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

    2014-01-01

    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. PMID:25320167

  2. 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.

  3. Gill Damage to Atlantic Salmon (Salmo salar) Caused by the Common Jellyfish (Aurelia aurita) under Experimental Challenge

    PubMed Central

    Baxter, Emily J.; Sturt, Michael M.; Ruane, Neil M.; Doyle, Thomas K.; McAllen, Rob; Harman, Luke; Rodger, Hamish D.

    2011-01-01

    Background Over recent decades jellyfish have caused fish kill events and recurrent gill problems in marine-farmed salmonids. Common jellyfish (Aurelia spp.) are among the most cosmopolitan jellyfish species in the oceans, with populations increasing in many coastal areas. The negative interaction between jellyfish and fish in aquaculture remains a poorly studied area of science. Thus, a recent fish mortality event in Ireland, involving Aurelia aurita, spurred an investigation into the effects of this jellyfish on marine-farmed salmon. Methodology/Principal Findings To address the in vivo impact of the common jellyfish (A. aurita) on salmonids, we exposed Atlantic salmon (Salmo salar) smolts to macerated A. aurita for 10 hrs under experimental challenge. Gill tissues of control and experimental treatment groups were scored with a system that rated the damage between 0 and 21 using a range of primary and secondary parameters. Our results revealed that A. aurita rapidly and extensively damaged the gills of S. salar, with the pathogenesis of the disorder progressing even after the jellyfish were removed. After only 2 hrs of exposure, significant multi-focal damage to gill tissues was apparent. The nature and extent of the damage increased up to 48 hrs from the start of the challenge. Although the gills remained extensively damaged at 3 wks from the start of the challenge trial, shortening of the gill lamellae and organisation of the cells indicated an attempt to repair the damage suffered. Conclusions Our findings clearly demonstrate that A. aurita can cause severe gill problems in marine-farmed fish. With aquaculture predicted to expand worldwide and evidence suggesting that jellyfish populations are increasing in some areas, this threat to aquaculture is of rising concern as significant losses due to jellyfish could be expected to increase in the future. PMID:21490977

  4. Sphingophosphonolipids, phospholipids, and fatty acids from Aegean jellyfish Aurelia aurita.

    PubMed

    Kariotoglou, D M; Mastronicolis, S K

    2001-11-01

    The goal of this study is to elucidate and identify several sphingophosphonolipids from Aurelia aurita, an abundant but harmless Aegean jellyfish, in which they have not previously been described. Total lipids of A. aurita were 0.031-0.036% of fresh tissue, and the lipid phosphorus content was 1.3-1.7% of total lipids. Phosphonolipids were 21.7% of phospholipids and consisted of a major ceramide aminoethylphosphonate (CAEP-I; 18.3%), as well as three minor CAEP (II, III, IV) methyl analogs at 1.3, 1.1, and 1.0%, respectively. The remaining phospholipid composition was: phosphatidylcholine, 44.5%, including 36.2% glycerylethers; phosphatidylethanolamine, 18.6%, including 4.5% glycerylethers; cardiolipin, 5.6%; phosphatidylinositol, 2.6%; and lysophosphatidylcholine, 5.0%. In CAEP-I, saturated fatty acids of 14-18 carbon chain length were 70.8% and were combined with 57.3% dihydroxy bases and 23.4% trihydroxy bases. The suite of the three minor CAEP methyl analogs were of the same lipid class based on the head group, but they separated into three different components because of their polarity as follows: CAEP-II and CAEP-III differentiation from the major CAEP-I was mainly due to the increased fatty acid unsaturation and not to a different long-chain base, but the CAEP-IV differentiation from CAEP-I, apart from fatty acid unsaturation, was due to the increased content of hydroxyl groups originated from both hydroxy fatty acids and trihydroxy long-chain bases. Saturated fatty acids were predominant in total (76.7%), polar (83.0%), and neutral lipids (67.6%) of A. aurita. The major phospholipid components of A. aurita were comparable to those previously found in a related organism (Pelagia noctiluca), which can injure humans. PMID:11795859

  5. Systematics and biogeography of the jellyfish Aurelia labiata (Cnidaria: Scyphozoa).

    PubMed

    Gershwin, L A

    2001-08-01

    The hypothesis that the common eastern North Pacific Aurelia is A. aurita is falsified with morphological analysis. The name Aurelia labiata is resurrected, and the species is redescribed, to refer to medusae differing from A. aurita by a suite of characters related to a broad and elongated manubrium. Specifically, the oral arms are short, separated by and arising from the base of the fleshy manubrium, and the planulae are brooded upon the manubrium itself, rather than on the oral arms. Aurelia aurita possesses no corresponding enlarged structure. Furthermore, the number of radial canals is typically much greater in A. labiata, and thus the canals often appear more anastomosed than in A. aurita. Finally, most A. labiata medusae possess a 16-scalloped bell margin, whereas the margin is 8-scalloped in most A. aurita. Separation of the two forms has previously been noted on the basis of allozyme and isozyme analyses and on the histology of the neuromuscular system. Partial 18S rDNA sequencing corroborates these findings. Three distinct morphotypes of A. labiata, corresponding to separate marine bioprovinces, have been identified among 17 populations from San Diego, California, to Prince William Sound, Alaska. The long-undisputed species A. limbata may be simply a color morph of A. labiata, or a species within a yet-unelaborated A. labiata species complex. The first known introduction of Aurelia cf. aurita into southern California waters is documented. Although traditional jellyfish taxonomy tends to recognize many species as cosmopolitan or nearly so, these results indicate that coastal species, such as A. labiata, may experience rapid divergence among isolated populations, and that the taxonomy of such species should therefore be scrutinized with special care. PMID:11526069

  6. Lithium and rubidium: effects on the rhythmic swimming movement of jellyfish (Aurelia aurita).

    PubMed

    Hoffmann, C; Smith, D F

    1979-09-15

    The effects of adding LiCl, RbCl, KCl or NaCl to sea water at concentrations up to 30 mmoles/1 on the frequency of contraction of jellyfish (Aurelia aurita) suggest that studies on phylogenetically low animals with relatively simple nervous systems may be of use to determine mechanisms of action of lithium and rudidium on movements. PMID:488270

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

    PubMed Central

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

    2016-01-01

    Background: 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. Methods: A predesigned questionnaire was distributed to 120 naval members in January 2015. The data of 108 respondents were included in the statistical analysis. Results: 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. Conclusions: 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. PMID:27447652

  8. Passive energy recapture in jellyfish contributes to propulsive advantage over other metazoans

    PubMed Central

    Gemmell, Brad J.; Costello, John H.; Colin, Sean P.; Stewart, Colin J.; Dabiri, John O.; Tafti, Danesh; Priya, Shashank

    2013-01-01

    Gelatinous zooplankton populations are well known for their ability to take over perturbed ecosystems. The ability of these animals to outcompete and functionally replace fish that exhibit an effective visual predatory mode is counterintuitive because jellyfish are described as inefficient swimmers that must rely on direct contact with prey to feed. We show that jellyfish exhibit a unique mechanism of passive energy recapture, which is exploited to allow them to travel 30% further each swimming cycle, thereby reducing metabolic energy demand by swimming muscles. By accounting for large interspecific differences in net metabolic rates, we demonstrate, contrary to prevailing views, that the jellyfish (Aurelia aurita) is one of the most energetically efficient propulsors on the planet, exhibiting a cost of transport (joules per kilogram per meter) lower than other metazoans. We estimate that reduced metabolic demand by passive energy recapture improves the cost of transport by 48%, allowing jellyfish to achieve the large sizes required for sufficient prey encounters. Pressure calculations, using both computational fluid dynamics and a newly developed method from empirical velocity field measurements, demonstrate that this extra thrust results from positive pressure created by a vortex ring underneath the bell during the refilling phase of swimming. These results demonstrate a physical basis for the ecological success of medusan swimmers despite their simple body plan. Results from this study also have implications for bioinspired design, where low-energy propulsion is required. PMID:24101461

  9. Vertical distribution of giant jellyfish, Nemopilema nomurai using acoustics and optics

    NASA Astrophysics Data System (ADS)

    Kim, Seonghun; Lee, Kyounghoon; Yoon, Won Duk; Lee, Hyungbeen; Hwang, Kangseok

    2016-03-01

    Nemopilema nomurai jellyfish, which are believed to complete their development in the East China Sea, have started migrating into the Yellow Sea in recent years. We obtained biomass estimates of this species in the Yellow Sea using bottom trawl fishing gear and sighting surveys over a 5-year period. These methods are effective for obtaining N. nomurai jellyfish density estimates and information about the community distribution near the bottom or surface of the sea. To verify the vertical distributions of giant jellyfish between, we used hydroacoustic equipment, including an optical stereo camera system attached to a towed sledge and an echo counting method with scientific echosounder system. Acoustic and optical data were collected while the vessel moved at 3 knots, from which the distribution and density of N. nomurai jellyfish were analyzed. Subsequently, the camera system was towed from a 7 m mean depth to sea level, with the detection range of the acoustic system extending from an 8 m depth to the bottom surface. The optical and acoustic methods indicated the presence of vertical distribution of 0.113 (inds/m3) and 0.064 (inds/m3), respectively. However, the vertical distribution indicated that around 93% of individuals occurred at a depth range of 10-40 m; thus, a 2.4-fold greater density was estimated by acoustic echo counting compared to the optical method.

  10. 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.

  11. Passive energy recapture in jellyfish contributes to propulsive advantage over other metazoans.

    PubMed

    Gemmell, Brad J; Costello, John H; Colin, Sean P; Stewart, Colin J; Dabiri, John O; Tafti, Danesh; Priya, Shashank

    2013-10-29

    Gelatinous zooplankton populations are well known for their ability to take over perturbed ecosystems. The ability of these animals to outcompete and functionally replace fish that exhibit an effective visual predatory mode is counterintuitive because jellyfish are described as inefficient swimmers that must rely on direct contact with prey to feed. We show that jellyfish exhibit a unique mechanism of passive energy recapture, which is exploited to allow them to travel 30% further each swimming cycle, thereby reducing metabolic energy demand by swimming muscles. By accounting for large interspecific differences in net metabolic rates, we demonstrate, contrary to prevailing views, that the jellyfish (Aurelia aurita) is one of the most energetically efficient propulsors on the planet, exhibiting a cost of transport (joules per kilogram per meter) lower than other metazoans. We estimate that reduced metabolic demand by passive energy recapture improves the cost of transport by 48%, allowing jellyfish to achieve the large sizes required for sufficient prey encounters. Pressure calculations, using both computational fluid dynamics and a newly developed method from empirical velocity field measurements, demonstrate that this extra thrust results from positive pressure created by a vortex ring underneath the bell during the refilling phase of swimming. These results demonstrate a physical basis for the ecological success of medusan swimmers despite their simple body plan. Results from this study also have implications for bioinspired design, where low-energy propulsion is required. PMID:24101461

  12. 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. PMID:24508769

  13. 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.

  14. Predation by jellyfish on large and emergent zooplankton: Implications for benthic pelagic coupling

    NASA Astrophysics Data System (ADS)

    Pitt, Kylie A.; Clement, Anne-Laure; Connolly, Rod M.; Thibault-Botha, Delphine

    2008-03-01

    Stable carbon isotopes were used to determine the contribution of emergent demersal zooplankton to the diet of the scyphozoan jellyfish Catostylus mosaicus at Smiths Lake, New South Wales, Australia. A preliminary study in 2004 indicated that there was no difference in the δ13C of ectodermal tissue and mesoglea of the medusae. In 2005, medusae and zooplankton present during the day and night were sampled and isotopic signatures were modelled using IsoSource. Modelling indicated that: (1) mollusc veligers and copepods sampled during the day contributed <13% of the carbon to the jellyfish; (2) copepods sampled at night contributed up to 25%; and (3) the large, emergent decapod Lucifer sp. contributed 88-94%. We hypothesised, therefore, that medusae derive most of their carbon from emergent species of zooplankton. In 2006, sampling done in 2005 was repeated three times over a period of 4 weeks to measure short-term temporal variation in isotopic signatures of medusae and zooplankton, and emergent demersal zooplankton was specifically sampled using emergence traps. Short-term temporal variation in isotopic signatures was observed for some taxa, however, actual variations were small (<1.5‰) and the values of medusae and zooplankton remained consistent relative to each other. IsoSource modelling revealed that mysid shrimp and emergent copepods together contributed 79-100% of the carbon to the jellyfish, and that the maximum possible contribution of daytime copepods and molluscs was only 22%. Jellyfish apparently derive most of their carbon from emergent zooplankton and by capturing small numbers of relatively large taxa, such as Lucifer sp. or mysid shrimp. Small but abundantly captured zooplankton (such as mollusc veligers) contribute only minor amounts of carbon. Jellyfish have a major role in the transfer of carbon between benthic and pelagic food webs in coastal systems.

  15. Neutralization of toxic effects of different crude jellyfish venoms by an extract of Ipomoea pes-caprae (L.) R. Br.

    PubMed

    Pongprayoon, U; Bohlin, L; Wasuwat, S

    1991-10-01

    An extract (IPA) of the plant Ipomoea pes-caprae (L.) R. Br., previously shown to be clinically effective toward dermatitis caused by venomous jellyfishes, was studied as to its ability to neutralize toxic activities of jellyfish venoms. Different venoms exhibited different degrees of activity. When IPA was incubated with active venoms, it inhibited the actions of all jellyfish venoms tested, with IC50 values in the range of 0.3-0.8 mgIPA/mg venom for proteolytic action, and with about 10 times lower IC50 values for the neutralization of haemolytic action. These activities of IPA support the previously reported effectiveness in the treatment of dermatitis caused by jellyfish sting. PMID:1684405

  16. 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.

  17. 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

  18. 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. PMID:27055563

  19. 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

  20. 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

  1. Reynolds number limits for jet propulsion: a numerical study of simplified jellyfish.

    PubMed

    Herschlag, Gregory; Miller, Laura

    2011-09-21

    The Scallop theorem states that reciprocal methods of locomotion, such as jet propulsion or paddling, will not work in Stokes flow (Reynolds number=0). In nature the effective limit of jet propulsion is still in the range where inertial forces are significant. It appears that almost all animals that use jet propulsion swim at Reynolds numbers (Re) of about 5 or more. Juvenile squid and octopods hatch from the egg already swimming in this inertial regime. Juvenile jellyfish, or ephyrae, break off from polyps swimming at Re greater than 5. Many other organisms, such as scallops, rarely swim at Re less than 100. The limitations of jet propulsion at intermediate Re is explored here using the immersed boundary method to solve the 2D Navier-Stokes equations coupled to the motion of a simplified jellyfish. The contraction and expansion kinematics are prescribed, but the forward and backward swimming motions of the idealized jellyfish are emergent properties determined by the resulting fluid dynamics. Simulations are performed for both an oblate bell shape using a paddling mode of swimming and a prolate bell shape using jet propulsion. Average forward velocities and work put into the system are calculated for Re between 1 and 320. The results show that forward velocities rapidly decay with decreasing Re for all bell shapes when Re<10. Similarly, the work required to generate the pulsing motion increases significantly for Re<10. When compared to actual organisms, the swimming velocities and vortex separation patterns for the model prolate agree with those observed in Nemopsis bachei. The forward swimming velocities of the model oblate jellyfish after two pulse cycles are comparable to those reported for Aurelia aurita, but discrepancies are observed in the vortex dynamics between when the 2D model oblate jellyfish and the organism. This discrepancy is likely due to a combination of the differences between the 3D reality of the jellyfish and the 2D simplification, as well as

  2. 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. PMID:26547837

  3. Dynamics of tethered versus free-swimming animals: A wake structure comparison in jellyfish

    NASA Astrophysics Data System (ADS)

    Katija, Kakani; Dabiri, John O.

    2006-11-01

    Previous research has shown that jellyfish utilize the formation and shedding of vortices to help feed and move the animal. Laboratory experiments often require restricting the motion of an animal by tethering/fluming to allow for repeatable results. However, past research has not addressed the differences that arise when the motion of an animal is restricted/confined. This presentation will attend to this issue by comparing the wake structure of a tethered and free-swimming Aurelia aurita. Digital Particle Image Velocimetry is used to collect measurements of the velocity field surrounding an animal that is either tethered or swimming freely. Dynamical systems methods are used to compute Lagrangian coherent structures (LCS), which is used to identify the geometries of structures in the wake of the animal. Using LCS, a comparison between the wake of a tethered and free-swimming animal can be made. This research provides a quantitative measure of the differences between a tethered and freely moving jellyfish.

  4. Faking giants: the evolution of high prey clearance rates in jellyfishes.

    PubMed

    Acuña, José Luis; López-Urrutia, Ángel; Colin, Sean

    2011-09-16

    Jellyfishes have functionally replaced several overexploited commercial stocks of planktivorous fishes. This is paradoxical, because they use a primitive prey capture mechanism requiring direct contact with the prey, whereas fishes use more efficient visual detection. We have compiled published data to show that, in spite of their primitive life-style, jellyfishes exhibit similar instantaneous prey clearance and respiration rates as their fish competitors and similar potential for growth and reproduction. To achieve this production, they have evolved large, water-laden bodies that increase prey contact rates. Although larger bodies are less efficient for swimming, optimization analysis reveals that large collectors are advantageous if they move through the water sufficiently slowly. PMID:21921197

  5. 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.

  6. An examination of the cardiovascular effects of an 'Irukandji' jellyfish, Alatina nr mordens.

    PubMed

    Winter, Kelly L; Isbister, Geoffrey K; Schneider, Jennifer J; Konstantakopoulos, Nicki; Seymour, Jamie E; Hodgson, Wayne C

    2008-07-10

    Irukandji syndrome is usually characterized by delayed severe abdominal, back and chest pain associated with autonomic effects including diaphoresis, hypertension and, in severe cases, myocardial injury and pulmonary oedema. It is most often associated with envenoming by the jellyfish Carukia barnesi, but a number of other jellyfish, including Alatina mordens, are now known to produce Irukandji syndrome. In the present study, nematocyst-derived venom from A. nr mordens (150-250 microg/kg, i.v.) produced a long-lasting pressor effect in anaesthetised rats. This pressor response (250 microg/kg, i.v.) was significantly inhibited by prior administration of the alpha-adrenoceptor antagonist prazosin (200 microg/kg, i.v.) but not by CSL box jellyfish antivenom (300 U/kg, i.v.). A. nr mordens venom 250 microg/kg (i.v.) caused marked increases in plasma adrenaline and noradrenaline concentrations following administration in anaesthetised rats. The venom did not contain appreciable amounts of either adrenaline or noradrenaline. A. nr mordens venom (25 microg/ml) produced a contractile response in rat electrically stimulated vas deferens which was markedly reduced in tissues pre-treated with reserpine (0.1mM) or guanethidine (0.1mM). Sodium dodecyl sulphate (SDS)-PAGE analysis showed that A. nr mordens venom is comprised of multiple protein bands ranging from 10 to 200 kDa. Western blot analysis using CSL box jellyfish antivenom indicated several antigenic proteins in A. nr mordens venom, however, it did not detect all proteins present in the venom. This study characterizes the in vitro and in vivo effects of A. nr mordens venom and indicates that the cardiovascular effects are at least partially mediated by endogenous catecholamine release. PMID:18547753

  7. 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. PMID:26546696

  8. Biomimetic jellyfish-inspired underwater vehicle actuated by ionic polymer metal composite actuators

    NASA Astrophysics Data System (ADS)

    Najem, Joseph; Sarles, Stephen A.; Akle, Barbar; Leo, Donald J.

    2012-09-01

    This paper presents the design, fabrication, and characterization of a biomimetic jellyfish robot that uses ionic polymer metal composites (IPMCs) as flexible actuators for propulsion. The shape and swimming style of this underwater vehicle are based on the Aequorea victoria jellyfish, which has an average swimming speed of 20 mm s-1 and which is known for its high swimming efficiency. The Aequorea victoria is chosen as a model system because both its bell morphology and kinematic properties match the mechanical properties of IPMC actuators. This medusa is characterized by its low swimming frequency, small bell deformation during the contraction phase, and high Froude efficiency. The critical components of the robot include the flexible bell that provides the overall shape and dimensions of the jellyfish, a central hub and a stage used to provide electrical connections and mechanical support to the actuators, eight distinct spars meant to keep the upper part of the bell stationary, and flexible IPMC actuators that extend radially from the central stage. The bell is fabricated from a commercially available heat-shrinkable polymer film to provide increased shape-holding ability and reduced weight. The IPMC actuators constructed for this study demonstrated peak-to-peak strains of ˜0.7% in water across a frequency range of 0.1-1.0 Hz. By tailoring the applied voltage waveform and the flexibility of the bell, the completed robotic jellyfish with four actuators swam at an average speed 0.77 mm s-1 and consumed 0.7 W. When eight actuators were used the average speed increased to 1.5 mm s-1 with a power consumption of 1.14 W.

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

    PubMed

    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

  10. A biomimetic robotic jellyfish (Robojelly) actuated by shape memory alloy composite actuators.

    PubMed

    Villanueva, Alex; Smith, Colin; Priya, Shashank

    2011-09-01

    An analysis is conducted on the design, fabrication and performance of an underwater vehicle mimicking the propulsion mechanism and physical appearance of a medusa (jellyfish). The robotic jellyfish called Robojelly mimics the morphology and kinematics of the Aurelia aurita species. Robojelly actuates using bio-inspired shape memory alloy composite actuators. A systematic fabrication technique was developed to replicate the essential structural features of A. aurita. Robojelly's body was fabricated from RTV silicone having a total mass of 242 g and bell diameter of 164 mm. Robojelly was able to generate enough thrust in static water conditions to propel itself and achieve a proficiency of 0.19 s(-1) while the A. aurita achieves a proficiency of around 0.25 s(-1). A thrust analysis based on empirical measurements for a natural jellyfish was used to compare the performance of the different robotic configurations. The configuration with best performance was a Robojelly with segmented bell and a passive flap structure. Robojelly was found to consume an average power on the order of 17 W with the actuators not having fully reached a thermal steady state. PMID:21852714

  11. 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

  12. A GLIMPSE of the Southern Jellyfish Nebula and Its Massive YSO

    NASA Astrophysics Data System (ADS)

    Mercer, E. P.; Clemens, D. P.; Rathborne, J. M.; Meade, M. R.; Babler, B. L.; Indebetouw, R.; Whitney, B. A.; Watson, C.; Wolfire, M. G.; Wolff, M. J.; Bania, T. M.; Benjamin, R. A.; Cohen, M.; Dickey, J. M.; Jackson, J. M.; Kobulnicky, H. A.; Mathis, J. S.; Stolovy, S. R.; Uzpen, B.; Churchwell, E. B.

    2007-02-01

    In Spitzer/IRAC images obtained under the GLIMPSE Legacy Survey, we have identified a unique and provocative nebular object we call the ``Southern Jellyfish Nebula.'' The Southern Jellyfish Nebula is characterized by a fan of narrow tendrils with extreme length-to-width ratios that emanate from the vicinity of a bright infrared point source embedded in a smaller resolved nebula. From CO observations of the Nebula's morphologically associated molecular cloud, we have derived a kinematic distance of 5.7+/-0.8 kpc and a cloud mass of 3.2+/-0.9×103 Msolar. The tendril-like ropes of the Nebula have widths of ~0.1 pc and lengths of up to ~2 pc. We have integrated the infrared spectral energy distribution (SED) of the point source to establish it as a massive young stellar object (MYSO), most likely forming alone, but possibly masking fainter cluster members. The shape of the SED is consistent with the shape of a late Class 0 SED model. Based on its far-IR luminosity of 3.3+/-0.9×104 Lsolar, the Southern Jellyfish's MYSO has a zero-age main sequence (ZAMS) spectral type of B0. Given the curious nature of this nebula, we suspect its peculiar IR-bright structure is directly related to its current state of star formation.

  13. 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

  14. 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.

  15. Signatures of active and passive optimized Lévy searching in jellyfish.

    PubMed

    Reynolds, Andy M

    2014-10-01

    Some of the strongest empirical support for Lévy search theory has come from telemetry data for the dive patterns of marine predators (sharks, bony fishes, sea turtles and penguins). The dive patterns of the unusually large jellyfish Rhizostoma octopus do, however, sit outside of current Lévy search theory which predicts that a single search strategy is optimal. When searching the water column, the movement patterns of these jellyfish change over time. Movement bouts can be approximated by a variety of Lévy and Brownian (exponential) walks. The adaptive value of this variation is not known. On some occasions movement pattern data are consistent with the jellyfish prospecting away from a preferred depth, not finding an improvement in conditions elsewhere and so returning to their original depth. This 'bounce' behaviour also sits outside of current Lévy walk search theory. Here, it is shown that the jellyfish movement patterns are consistent with their using optimized 'fast simulated annealing'--a novel kind of Lévy walk search pattern--to locate the maximum prey concentration in the water column and/or to locate the strongest of many olfactory trails emanating from more distant prey. Fast simulated annealing is a powerful stochastic search algorithm for locating a global maximum that is hidden among many poorer local maxima in a large search space. This new finding shows that the notion of active optimized Lévy walk searching is not limited to the search for randomly and sparsely distributed resources, as previously thought, but can be extended to embrace other scenarios, including that of the jellyfish R. octopus. In the presence of convective currents, it could become energetically favourable to search the water column by riding the convective currents. Here, it is shown that these passive movements can be represented accurately by Lévy walks of the type occasionally seen in R. octopus. This result vividly illustrates that Lévy walks are not necessarily

  16. Signatures of active and passive optimized Lévy searching in jellyfish

    PubMed Central

    Reynolds, Andy M.

    2014-01-01

    Some of the strongest empirical support for Lévy search theory has come from telemetry data for the dive patterns of marine predators (sharks, bony fishes, sea turtles and penguins). The dive patterns of the unusually large jellyfish Rhizostoma octopus do, however, sit outside of current Lévy search theory which predicts that a single search strategy is optimal. When searching the water column, the movement patterns of these jellyfish change over time. Movement bouts can be approximated by a variety of Lévy and Brownian (exponential) walks. The adaptive value of this variation is not known. On some occasions movement pattern data are consistent with the jellyfish prospecting away from a preferred depth, not finding an improvement in conditions elsewhere and so returning to their original depth. This ‘bounce’ behaviour also sits outside of current Lévy walk search theory. Here, it is shown that the jellyfish movement patterns are consistent with their using optimized ‘fast simulated annealing’—a novel kind of Lévy walk search pattern—to locate the maximum prey concentration in the water column and/or to locate the strongest of many olfactory trails emanating from more distant prey. Fast simulated annealing is a powerful stochastic search algorithm for locating a global maximum that is hidden among many poorer local maxima in a large search space. This new finding shows that the notion of active optimized Lévy walk searching is not limited to the search for randomly and sparsely distributed resources, as previously thought, but can be extended to embrace other scenarios, including that of the jellyfish R. octopus. In the presence of convective currents, it could become energetically favourable to search the water column by riding the convective currents. Here, it is shown that these passive movements can be represented accurately by Lévy walks of the type occasionally seen in R. octopus. This result vividly illustrates that Lévy walks are not

  17. 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

  18. Jellyfish life histories: role of polyps in forming and maintaining scyphomedusa populations.

    PubMed

    Lucas, Cathy H; Graham, William M; Widmer, Chad

    2012-01-01

    Large population fluctuations of jellyfish occur over a variety of temporal scales, from weekly to seasonal, inter-annual and even decadal, with some regions of the world reported to be experiencing persistent seasonal bloom events. Recent jellyfish research has focussed on understanding the causes and consequences of these population changes, with the vast majority of studies considering the effect of changing environmental variables only on the pelagic medusa. But many of the bloom-forming species are members of the Scyphozoa with complex metagenic life cycles consisting of a sexually reproducing pelagic medusa and asexually reproducing benthic polyp. Recruitment success during the juvenile (planula, polyp and ephyrae) stages of the life cycle can have a major effect on the abundance of the adult (medusa) population, but until very recently, little was known about the ecology of the polyp or scyphistoma phase of the scyphozoan life cycle. The aim of this review is to synthesise the current state of knowledge of polyp ecology by examining (1) the recruitment and metamorphosis of planulae larvae into polyps, (2) survival and longevity of polyps, (3) expansion of polyp populations via asexual propagation and (4) strobilation and recruitment of ephyrae (juvenile medusae). Where possible, comparisons are made with the life histories of other bentho-pelagic marine invertebrates so that further inferences can be made. Differences between tropical and temperate species are highlighted and related to climate change, and populations of the same species (in particular Aurelia aurita) inhabiting different habitats within its geographic range are compared. The roles that polyps play in ensuring the long-term survival of jellyfish populations as well as in the formation of bloom populations are considered, and recommendations for future research are presented. PMID:22877612

  19. The ontogenetic scaling of hydrodynamics and swimming performance in jellyfish (Aurelia aurita).

    PubMed

    McHenry, Matthew J; Jed, Jason

    2003-11-01

    It is not well understood how ontogenetic changes in the motion and morphology of aquatic animals influence the performance of swimming. The goals of the present study were to understand how changes in size, shape and behavior affect the hydrodynamics of jet propulsion in the jellyfish Aurelia aurita and to explore how such changes affect the ontogenetic scaling of swimming speed and cost of transport. We measured the kinematics of jellyfish swimming from video recordings and simulated the hydrodynamics of swimming with two computational models that calculated thrust generation by paddle and jet mechanisms. Our results suggest that thrust is generated primarily by jetting and that there is negligible thrust generation by paddling. We examined how fluid forces scaled with body mass using the jet model. Despite an ontogenetic increase in the range of motion by the bell diameter and a decrease in the height-to-diameter ratio, we found that thrust and acceleration reaction scaled with body mass as predicted by kinematic similarity. However, jellyfish decreased their pulse frequency with growth, and speed consequently scaled at a lower exponential rate than predicted by kinematic similarity. Model simulations suggest that the allometric growth in Aurelia results in swimming that is slower, but more energetically economical, than isometric growth with a prolate bell shape. The decrease in pulse frequency over ontogeny allows large Aurelia medusae to avoid a high cost of transport but generates slower swimming than if they maintained a high pulse frequency. Our findings suggest that ontogenetic change in the height-to-diameter ratio and pulse frequency of Aurelia results in swimming that is relatively moderate in speed but is energetically economical. PMID:14555752

  20. 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

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

    NASA Astrophysics Data System (ADS)

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

    1994-08-01

    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 (JfT 4), needed for ephyra production. Since iodine-treated polyps strobilated and formed ephyrae in space, it appears that jellyfish can synthesize Jf-T4 in space. Indeed, two groups of polyps not given inducer formed ephryae in space, presumably due to enhanced Jf-T4 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 numbers (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.

  2. 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. PMID:26647170

  3. 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.

  4. 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.

  5. In vivo analysis of effects of venom from the jellyfish Chrysaora sp. in zebrafish (Danio rerio).

    PubMed

    Becerra-Amezcua, Mayra P; Guerrero-Legarreta, Isabel; González-Márquez, Humberto; Guzmán-García, Xochitl

    2016-04-01

    The jellyfishes of the genus Chrysaora are present in all of the world's oceans, but the toxicity of their venoms has not yet been thoroughly characterized. The zebrafish as a toxicology model can be used for general toxicity testing of drugs and the investigation of toxicological mechanisms. The aim of this study was to evaluate the effect of crude venom from jellyfish Chrysaora sp., a species of jellyfish observed in the tropical lagoons of the Gulf of Mexico, on the zebrafish Danio rerio. Juvenile zebrafish were injected with different concentrations of venom from Chrysaora sp. via intraperitoneal and subcutaneous injections. The effects of the venom were determined by histopathological analysis and through the measurement of hemolytic and phospholipase A2 activities. The crude venom was examined by SDS-PAGE. The effect of sublethal concentrations of crude venom from Chrysaora sp. on D. rerio was hemorrhaging in the eyes, while the histopathological analysis demonstrated that the primary organs targeted were the pseudobranch, which displayed hyperemia, and the gill, which displayed hyperplasia and hypertrophy. The blood analysis exhibited hemolysis, nuclear abnormalities, and echinocytes by the action of phospholipase A2, which was determined to have 596 units of activity/mg of protein in the venom. The crude venom has proteins with molecular weights ranging from 250 to 6 kDa, with more density in the bands corresponding to 70, 20 and 15 kDa. The venom of Chysaora sp. caused disturbances in circulation associated with vascular dilation due to the localized release of inflammatory mediators. The hemolysis of erythrocytes was caused by the action of phospholipase A2. These findings not only provide an excellent study model but also have a great pharmacological potential for designing new drugs and for the elucidation of the mechanisms of action of and treatment against stings. PMID:26876134

  6. 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.

  7. Nemopilema nomurai Jellyfish venom treatment leads to alterations in rat cardiomyocytes proteome

    PubMed Central

    Choudhary, Indu; Lee, Hyunkyoung; Pyo, Min-Jung; Heo, Yunwi; Bae, Seong Kyeong; Kwon, Young Chul; Yoon, Won Duk; Kang, Changkeun; Kim, Euikyung

    2015-01-01

    This data article restrains data associated to the Choudhary et al. [1]. Nemopilema nomurai Jellyfish venom (NnV) can lead to cardiac toxicity. Here we analyzed the effect of NnV on rat cardiomyocytes cell line H9c2 at the proteome level using two-dimensional gel electrophoresis and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF/MS). This analysis resulted in 34 proteins with differential expression. Here we provide the dataset for the proteins with amplified or reduced level as compare to control. PMID:26702416

  8. Dimeric Octaketide Spiroketals from the Jellyfish-Derived Fungus Paecilomyces variotii J08NF-1.

    PubMed

    Wang, Haibo; Hong, Jongki; Yin, Jun; Moon, Hyung Ryong; Liu, Yonghong; Wei, Xiaoyi; Oh, Dong-Chan; Jung, Jee H

    2015-11-25

    Paeciloketals (1-3), new benzannulated spiroketal derivatives, were isolated from the marine fungus Paecilomyces variotii derived from the giant jellyfish Nemopilema nomurai. Compound 1 was present as a racemate and was resolved into enantiopure 1a and 1b by chiral-phase separation on a cellulose column. Compounds 2 and 3, possessing a novel benzannulated spiroketal skeleton, were rapidly interconvertible and yielded an equilibrium mixture on standing at room temperature. The relative and absolute configurations of compounds 2 and 3 were determined by NOESY analysis and ECD calculations. Compound 1 showed modest antibacterial activity against the marine pathogen Vibrio ichthyoenteri. PMID:26562481

  9. Nemopilema nomurai Jellyfish venom treatment leads to alterations in rat cardiomyocytes proteome.

    PubMed

    Choudhary, Indu; Lee, Hyunkyoung; Pyo, Min-Jung; Heo, Yunwi; Bae, Seong Kyeong; Kwon, Young Chul; Yoon, Won Duk; Kang, Changkeun; Kim, Euikyung

    2015-12-01

    This data article restrains data associated to the Choudhary et al. [1]. Nemopilema nomurai Jellyfish venom (NnV) can lead to cardiac toxicity. Here we analyzed the effect of NnV on rat cardiomyocytes cell line H9c2 at the proteome level using two-dimensional gel electrophoresis and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF/MS). This analysis resulted in 34 proteins with differential expression. Here we provide the dataset for the proteins with amplified or reduced level as compare to control. PMID:26702416

  10. Epicoccamide, a novel secondary metabolite from a jellyfish-derived culture of Epicoccum purpurascens.

    PubMed

    Wright, Anthony D; Osterhage, Claudia; König, Gabriele M

    2003-02-01

    From the inner tissue of the jellyfish Aurelia aurita a marine strain of the fungus Epicoccum purpurascens was obtained. After mass cultivation the fungus was investigated for its secondary metabolite content and found to contain the new, and most unusual tetramic acid derivative, epicoccamide (1). Epicoccamide is quite unusual since it is composed of three biosynthetically distinct subunits; glycosidic, fatty acid and tetramic acid (amino acid). The structure of the new compound was elucidated using spectroscopic methods, mainly 1D and 2D NMR, ESI-MS, and chemical degradations. PMID:12926253

  11. 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

  12. 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. PMID:26053674

  13. Indomethacin induction of metamorphosis from the asexual stage to sexual stage in the moon jellyfish, Aurelia aurita.

    PubMed

    Kuniyoshi, Hisato; Okumura, Izumi; Kuroda, Rie; Tsujita, Natsumi; Arakawa, Kenji; Shoji, Jun; Saito, Tamio; Osada, Hiroyuki

    2012-01-01

    We found while screening a chemical library that indomethacin, an inhibitor of prostaglandin biosynthesis, induced strobilation (metamorphosis from the asexual to sexual stage) in the moon jellyfish, Aurelia aurita. Indomethacin initiated strobilation in a dose-dependent manner, but was not involved in the progression of strobilation. Pharmacological experiments suggested that indomethacin could induce strobilation independently of prostaglandin biosynthesis. PMID:22785488

  14. A jellyfish-inspired jet propulsion robot actuated by an iris mechanism

    NASA Astrophysics Data System (ADS)

    Marut, Kenneth; Stewart, Colin; Michael, Tyler; Villanueva, Alex; Priya, Shashank

    2013-09-01

    A jellyfish-inspired jet propulsion robot (JetPRo) is designed, fabricated, and characterized with the objective of creating a fast-swimming uncrewed undersea vehicle. JetPRo measures 7.9 cm in height, 5.7 cm in diameter and is designed to mimic the proficient jetting propulsion mechanism used by the hydromedusa Sarsia tubulosa, which measures approximately 1 cm in diameter. In order to achieve the uniform-bell contraction used by S. tubulosa, we develop a novel circumferential actuation technique based on a mechanical iris diaphragm. When triggered, this mechanism induces a volumetric change of a deformable silicone cavity to expel a jet of fluid and produces positive thrust. A theoretical jetting model is used to optimize JetPRo’s gait for maximum steady-state swimming velocity, a result achieved by minimizing the timing between the contraction and relaxation phases. We validate this finding empirically and quantify the swimming performance of the robot using video tracking and time resolved digital particle image velocimetry. JetPRo was able to produce discrete vortex rings shed before pinch off and swim upwards with a maximum steady-state velocity of 11.6 cm s-1, outperforming current state-of-the-art robotic jellyfish in velocity as well as diameter-normalized velocity.

  15. Ontogeny of swimming speed, schooling behaviour and jellyfish avoidance by Japanese anchovy Engraulis japonicus.

    PubMed

    Masuda, R

    2011-05-01

    The ontogeny of swimming speed, schooling behaviour and jellyfish avoidance was studied in hatchery-reared Japanese anchovy Engraulis japonicus to compare its life-history strategy with two other common pelagic fishes, jack mackerel Trachurus japonicus and chub mackerel Scomber japonicus. Cruise swimming speed of E. japonicus increased allometrically from 1·4 to 3·9 standard length (L(S) ) per s (L(S) s(-1) ) from early larval to metamorphosing stage. Burst swimming speed also increased from 6·1 to 28 L(S) s(-1) in these stages. Cruise speed was inferior to that of S. japonicus, as was burst speed to that of T. japonicus. Engraulis japonicus larvae were highly vulnerable to predation by moon jellyfish Aurelia aurita and were readily eaten until they reached 23 mm L(S) , but not at 26 mm L(S) . Schooling behaviour (indicated by parallel swimming) started at c. 17 mm L(S) . Average distance to the nearest neighbour was shorter than values reported in other pelagic fishes. The relatively low predator avoidance capability of E. japonicus may be compensated for by their transparent and thus less conspicuous body, in addition to their early maturation and high fecundity. PMID:21539545

  16. NMR study on a novel mucin from jellyfish in natural abundance, Qniumucin from Aurelia aurita.

    PubMed

    Uzawa, Jun; Urai, Makoto; Baba, Takayuki; Seki, Hiroko; Taniguchi, Kayoko; Ushida, Kiminori

    2009-05-22

    A novel mucin (qniumucin), which we recently discovered in jellyfish, was investigated by several NMR techniques. Almost all the peaks in the (13)C and proton NMR spectra were satisfactorily assigned to the amino acids in the main chain and to the bridging GalNAc, the major sugar in the saccharide branches. The amino acid sequence in the tandem repeat part (-VVETTAAP-) was reconfirmed by the cross-peaks between alpha protons and carbonyl carbons in the HMBC spectrum. A connectivity analysis around the O-glycoside bond (GalNAc-Thr) was also performed, and detailed information on the local configuration was obtained by the DPFGSE-NOE-HSD technique. The strategy and the results described in this paper can be extended to the structural analysis of general O-glycan chains, which are more complex than the present mucin. NMR analyses reveal the simple structure of qniumucin extracted by the present protocol, and the homogeneity and purity of qniumucin are probably the result of it being extracted from jellyfish, a primitive animal. PMID:19371080

  17. Optimal stroke patterns for a model jellyfish swimmer with thin, flexible body

    NASA Astrophysics Data System (ADS)

    Peng, Jifeng; Dabiri, John

    2007-11-01

    In this study, a numerical model is built to simulate swimming of oblate jellyfish (e.g. Aurelia aurita). The model swimmer is a thin, axisymmetric circular plate which is flexible and is able to deform, mimicking contraction and relaxation of a jellyfish. Using body deformation, the swimmer is able to swim by shedding vortices into fluid wake. A prescribed body motion extracted from a free-swimming Aurelia aurita is applied to the swimmer. The induced vortex wake is solved by a vortex sheet method and is compared with the wake of the free-swimming Aurelia aurita measured by PIV. The stoke pattern of the swimmer is optimized for minimal cost of locomotion. The body kinematics are parameterized and cost of locomotion is calculated from simulation using the vortex sheet method. A surrogate management framework is used as the optimization scheme. The vortex wake induced by the optimal stroke pattern is investigated to identify the characteristics of the wake which enhance swimming performance.

  18. Mesogleal cells of the jellyfish Aurelia aurita are involved in the formation of mesogleal fibres.

    PubMed

    Shaposhnikova, Tatiana; Matveev, Ivan; Napara, Tatiana; Podgornaya, Olga

    2005-11-01

    The extracellular matrix of the jellyfish Aurelia aurita (Scyphozoa, Cnidaria), known as the mesoglea, is populated by numerous mesogleal cells (Mc). We determined the pattern of the Mc and the mesoglea, raised polyclonal antibodies (RA47) against the major mesogleal protein pA47 (47 kDa) and checked their specificity. In the mesoglea, RA47 stains pA47 itself. In immunoblots of Mc, RA47 stains bands of 120 kDa and 80 kDa; weaker staining is observed at pA47. The same staining pattern is seen on blots of jellyfish epidermal cells and of whole Hydra (Hydrozoa) or isolated mesoglea of Hydra. Our data indicate that pA47 is synthesized by Mc and epidermal cells as high molecular precursors. Using immunostaining techniques, we showed Mc to be involved in the formation of mesogleal non-collagenous (called "elastic" in classic morphological studies) fibres. The biochemical and morphological data suggest that Mc originate from the epidermis. PMID:16242363

  19. Modeling and optimization of IPMC actuator for autonomous jellyfish vehicle (AJV)

    NASA Astrophysics Data System (ADS)

    Joshi, Keyur B.; Akle, Barbar J.; Leo, Donald J.; Priya, Shashank

    2011-04-01

    Ionomeric Polymer Metal Composite (IPMC) actuators generate high flexural strains at small voltage amplitudes of 2-5V. IPMCs bend toward the anode when a potential drop is applied across its thickness. The actuation mechanism is due to the motion of ions inside it; which requires a form of hydration to dissociate and mobilize the charges. In our group IPMCs are developed either water based or Ionic Liquid based which is also known as the dry IPMCs. This combination of small voltage requirement with operation in both dry and underwater conditions makes the IPMCs a viable alternative for an Autonomous Jellyfish Vehicle (AJV). In this study, we estimate the mechanical properties of IPMC actuator having curved geometry using FEM model to match the experimental deformation. We combine the results from an electric model to estimate charge accumulated on electrode surface with piezoelectric model to estimate stress due to this charge accumulation. In the last step, the results are integrated with a structural model to simulate the actuator deformation. We have designed an AJV with embedded IPMC actuators using these properties to achieve the curvature of relaxed and contracted Jellyfish (Aurelia Aurita). Bio-mimetic deformation profile was achieved by using structural mechanics of beams with large deformation with only application of +/- 0.8V to optimized beam within 8.1% error norm in relaxed state and 21.3% in contracted state, with only -0.24% to 0.26% maximum flexural strain at maximum curvature point in contracted state.

  20. In vitro and in vivo haemolytic studies of tentacle-only extract from jellyfish Cyanea capillata.

    PubMed

    Xiao, Liang; Zhang, Jing; Wang, Qian-qian; He, Qian; Liu, Si-hua; Li, Yue; Zhang, Li-ming

    2010-06-01

    To approach the real haemolytic process of jellyfish toxins, both in vitro and in vivo haemolysis of tentacle-only extract (TOE) from jellyfish Cyanea capillata has been studied. Dose-response curves of the haemolytic activity of TOE in vitro were sigmoid shaped in both erythrocyte suspension and diluted whole blood, with the former more sensitive to TOE. The in vivo haemolysis increased sharply in the first 10 min and was followed by a gradual increase in the following 3h, with increasing blood potassium and lactic acid accordingly. SC5b-9 complexes were significantly up-regulated in vitro, but not in vivo. These results showed that the haemolysis of TOE in diluted whole blood and in vivo is not totally consistent with that in the erythrocyte suspension, and blood plasma might play a protective role against haemolysis. Thus we suggested that erythrocyte suspension can be used to test the damage of toxin on erythrocyte membrane, while the diluted whole blood may be more suitable to test the haemolysis of toxins. PMID:20149860

  1. Morphology controlling method for amorphous silica nanoparticles and jellyfish-like nanowires and their luminescence properties

    NASA Astrophysics Data System (ADS)

    Liu, Haitao; Huang, Zhaohui; Huang, Juntong; Xu, Song; Fang, Minghao; Liu, Yan-Gai; Wu, Xiaowen; Zhang, Shaowei

    2016-03-01

    Uniform silica nanoparticles and jellyfish-like nanowires were synthesized by a chemical vapour deposition method on Si substrates treated without and with Ni(NO3)2, using silicon powder as the source material. Composition and structural characterization using field emission scanning electron microscopy, transmission electron microscopy, energy dispersive X-ray spectroscopy and fourier-transform infrared spectroscopy showed that the as-prepared products were silica nanoparticles and nanowires which have amorphous structures. The form of nanoparticles should be related to gas-phase nucleation procedure. The growth of the nanowires was in accordance with vapour-liquid-solid mechanism, followed by Ostwald ripening to form the jellyfish-like morphology. Photoluminescence and cathodoluminescence measurements showed that the silica products excited by different light sources show different luminescence properties. The emission spectra of both silica nanoparticles and nanowires are due to the neutral oxygen vacancies (≡Si-Si≡). The as-synthesized silica with controlled morphology can find potential applications in future nanodevices with tailorable photoelectric properties.

  2. JetSum: SMA actuator based undersea unmanned vehicle inspired by jellyfish bio-mechanics

    NASA Astrophysics Data System (ADS)

    Bressers, Scott; Chung, Sanghun; Villanueva, Alex; Smith, Colin; Priya, Shashank

    2010-04-01

    Previously, we reported an undersea unmanned vehicle (UUV) termed as JetSum, inspired by the locomotion of medusa jellyfish, [12]. The propulsion of JetSum was based on shape memory alloy (SMA) wires replicating the contraction-relaxation cycle of natural jellyfish locomotion. In this paper, we report modified design of JetSum that addresses problems related to electrical isolation and power consumption. The modifications lead to significant improvement in functionality, providing implementation of a full continuous bell, bolstering critical sealing junctions, and reducing the overall power requirement. A LabVIEW controller program was developed to automate and optimize the driving of JetSum enabling reduction in power consumption for full contraction of SMA. JetSum locomotion in underwater conditions was recorded by using a high-speed camera and analyzed with image processing techniques developed in MatLab. The results show that JetSum was able to achieve velocity of 7 cm/s with power consumption of 8.94 W per cycle.

  3. 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. PMID:24360414

  4. 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

  5. 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. PMID:27127044

  6. 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.

  7. Ciguatera poisoning after ingestion of imported jellyfish: diagnostic application of serum immunoassay.

    PubMed

    Zlotnick, B A; Hintz, S; Park, D L; Auerbach, P S

    1995-08-01

    Ciguatera fish poisoning is an important public health problem wherever humans consume tropical and subtropical fish. It accounts for over half of fish-related poisonings in the United States but is uncommonly diagnosed and underreported. Produced by dinoflagellates, ciguatoxin accumulates up the food chain in herbivorous and carnivorous fishes. Cnidaria jellyfish and related invertebrates) have not previously been associated with direct ciguatera intoxication in humans. We report the first case of ciguatera fish poisoning associated with cnidarian ingestion. A 12-year-old Tongan female presented to our Emergency Department with mid-abdominal pain, nausea, change in mental status, and new-onset movement disorder after ingestion of jellyfish imported from American Samoa. Clinical diagnosis was confirmed by strongly positive serum identification of ciguatoxin and related polyether toxins (including okadaic acid) with a rapid extraction method (REM) and highly reliable solid-phase immunobead assay (S-PIA) performed by the Food Toxicology Research Group, University of Arizona. Ciguatera pathophysiology, clinical presentation, differential diagnosis (including consideration of palytoxin poisoning), and treatment are briefly reviewed. We emphasize the growing incidence of ciguatera fish poisoning outside "high-risk" areas. In regions with immigrant populations, privately imported exotic fish may be toxin vectors. Marine species other than carnivorous fish are now suspect in human ciguatera intoxication. Reliable tests can aid in premarket fish testing, diagnosis, and follow-up of ciguatera fish poisoning. The global prevalence of marine toxins demands fishermen, consumers, and physicians maintain a high index of suspicion for ciguatera fish poisoning. PMID:11990093

  8. 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. PMID:26241309

  9. Morphology controlling method for amorphous silica nanoparticles and jellyfish-like nanowires and their luminescence properties.

    PubMed

    Liu, Haitao; Huang, Zhaohui; Huang, Juntong; Xu, Song; Fang, Minghao; Liu, Yan-Gai; Wu, Xiaowen; Zhang, Shaowei

    2016-01-01

    Uniform silica nanoparticles and jellyfish-like nanowires were synthesized by a chemical vapour deposition method on Si substrates treated without and with Ni(NO3)2, using silicon powder as the source material. Composition and structural characterization using field emission scanning electron microscopy, transmission electron microscopy, energy dispersive X-ray spectroscopy and fourier-transform infrared spectroscopy showed that the as-prepared products were silica nanoparticles and nanowires which have amorphous structures. The form of nanoparticles should be related to gas-phase nucleation procedure. The growth of the nanowires was in accordance with vapour-liquid-solid mechanism, followed by Ostwald ripening to form the jellyfish-like morphology. Photoluminescence and cathodoluminescence measurements showed that the silica products excited by different light sources show different luminescence properties. The emission spectra of both silica nanoparticles and nanowires are due to the neutral oxygen vacancies (≡Si-Si≡). The as-synthesized silica with controlled morphology can find potential applications in future nanodevices with tailorable photoelectric properties. PMID:26940294

  10. Morphology controlling method for amorphous silica nanoparticles and jellyfish-like nanowires and their luminescence properties

    PubMed Central

    Liu, Haitao; Huang, Zhaohui; Huang, Juntong; Xu, Song; Fang, Minghao; Liu, Yan-gai; Wu, Xiaowen; Zhang, Shaowei

    2016-01-01

    Uniform silica nanoparticles and jellyfish-like nanowires were synthesized by a chemical vapour deposition method on Si substrates treated without and with Ni(NO3)2, using silicon powder as the source material. Composition and structural characterization using field emission scanning electron microscopy, transmission electron microscopy, energy dispersive X-ray spectroscopy and fourier-transform infrared spectroscopy showed that the as-prepared products were silica nanoparticles and nanowires which have amorphous structures. The form of nanoparticles should be related to gas-phase nucleation procedure. The growth of the nanowires was in accordance with vapour-liquid-solid mechanism, followed by Ostwald ripening to form the jellyfish-like morphology. Photoluminescence and cathodoluminescence measurements showed that the silica products excited by different light sources show different luminescence properties. The emission spectra of both silica nanoparticles and nanowires are due to the neutral oxygen vacancies (≡Si-Si≡). The as-synthesized silica with controlled morphology can find potential applications in future nanodevices with tailorable photoelectric properties. PMID:26940294

  11. 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

  12. 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

  13. 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

  14. 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. PMID:24194856

  15. 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.

  16. Effect of Venom from the Jellyfish Nemopilema nomurai on the Silkworm Bombyx mori L

    PubMed Central

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

    2015-01-01

    The silkworm Bombyx mori L. (B. mori) has a significant impact on the economy by producing more than 80% of the globally produced raw silk. The exposure of silkworm to pesticides may cause adverse effects on B. mori, such as a reduction in the production and quality of silk. This study aims to assay the effect of venom from the jellyfish Nemopilema nomurai on growth, cuticle and acetylcholinesterase (AChE) activity of the silkworm B. mori by the leaf dipping method. The experimental results revealed that the four samples caused neither antifeeding nor a lethal effect on B. mori. The sample SFV inhibited B. mori growth after 6 days of treatment in a dose-dependent manner. The samples SFV, DSFV and Fr-1 inhibited the precipitation and synthesis of chitin in the cuticle after 12 and 14 days of treatment. In the case of the four samples, the AChE was significantly improved after 14 days of treatment. PMID:26404374

  17. A Simple Computational Model of a jellyfish-like flying machine

    NASA Astrophysics Data System (ADS)

    Fang, Fang; Ristroph, Leif; Shelley, Michael

    2013-11-01

    We explore theoretically the aerodynamics of a jellyfish-like flying machine recently fabricated at NYU. This experimental device achieves flight and hovering by opening and closing a set of flapping wings. It displays orientational flight stability without additional control surfaces or feedback control. Our model machine consists of two symmetric massless flapping wings connected to a body with mass and moment of inertia. A vortex sheet shedding and wake model is used for the flow simulation. Use of the Fast Multipole Method (FMM), and adaptive addition/deletion of vortices, allows us to simulate for long times and resolve complex wakes. We use our model to explore the physical parameters that maintain body hovering, its ascent and descent, and investigate the stability of these states.

  18. Structural analysis of O-glycans of mucin from jellyfish (Aurelia aurita) containing 2-aminoethylphosphonate.

    PubMed

    Urai, Makoto; Nakamura, Takemichi; Uzawa, Jun; Baba, Takayuki; Taniguchi, Kayoko; Seki, Hiroko; Ushida, Kiminori

    2009-11-01

    The structure of O-glycan in qniumucin (Q-mucin), which is a novel mucin extracted from jellyfish, was analyzed by a combination of NMR and ESI-MS/MS. A previously unidentified monosaccharide involved in the glycan chains was determined to be N-acetylgalactosamine (GalNAc) substituted by 2-aminoethylphosphonate (AEP) at the C-6. The O-glycans in Q-mucin from Aurelia aurita were proved to be mainly composed of three monosaccharides: GalNAc, AEP-(O-->6)-GalNAc, and P-6-GalNAc. To the best of our knowledge, this is the first example of an O-glycan structure of glycoproteins containing AEP. This exceptionally simple structure of Q-mucin and its potential use in material science and technology are revealed. PMID:19732869

  19. 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. PMID:23488923

  20. Exploring vortex enhancement and manipulation mechanisms in jellyfish that contributes to energetically efficient propulsion

    PubMed Central

    Gemmell, Brad J; Costello, John H; Colin, Sean P

    2014-01-01

    The ability of animals to propel themselves efficiently through a fluid medium is ecologically advantageous. Flexible components that influence vortex interactions are widespread among animal propulsors. However the mechanisms by which vortices are enhanced and appropriately positioned for thrust generation are still poorly understood. Here, we describe how kinematic propulsor movements of a jellyfish can enhance and reposition a vortex ring that allows the recapture of wake energy for secondary thrust generation and efficient locomotion. We use high-speed video and digital particle image velocimetry (DPIV) to resolve kinematics simultaneously with fluid structures. These results provide new insight into how animals can manipulate fluid structures to reduce metabolic energy demands of swimming muscles and may have implications in bio-inspired design. PMID:25346796

  1. From jellyfish to biosensors: the use of fluorescent proteins in plants.

    PubMed

    Voss, Ute; Larrieu, Antoine; Wells, Darren M

    2013-01-01

    The milestone discovery of green fluorescent protein (GFP) from the jellyfish Aequorea victoria, its optimisation for efficient use in plantae, and subsequent improvements in techniques for fluorescent detection and quantification have changed plant molecular biology research dramatically. Using fluorescent protein tags allows the temporal and spatial monitoring of dynamic expression patterns at tissue, cellular and subcellular scales. Genetically-encoded fluorescence has become the basis for applications such as cell-type specific transcriptomics, monitoring cell fate and identity during development of individual organs or embryos, and visualising protein-protein interactions in vivo. In this article, we will give an overview of currently available fluorescent proteins, their applications in plant research, the techniques used to analyse them and, using the recent development of an auxin sensor as an example, discuss the design principles and prospects for the next generation of fluorescent plant biosensors. PMID:24166435

  2. 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. PMID:26219225

  3. 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

    2014-09-01

    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]. PMID:25248421

  4. Vortex formation analysis of a piston-cylinder apparatus with passively varying output inspired by jellyfish

    NASA Astrophysics Data System (ADS)

    Villanueva, Alex; Priya, Shashank

    2012-11-01

    The flow analysis of a robotic jellyfish (Robojelly) has led to the observation of an increase in performance due to passive flexible margin. Flexible margin are common on animals using an oscillating mode of propulsion. The understanding of flexible margins is therefore important for a better understanding of animal propulsion and bio-inspired propulsion. This work focuses on analyzing the effects of stiffness and geometry of flexible margins. A piston-cylinder apparatus was used with flexible margin at the output to test the different flexible margin configurations. These results characterize the effects of the different flexible margin parameters on vortex circulation and size. Office of Naval Research through contract number N00014-08-1-0654.

  5. Effect of Venom from the Jellyfish Nemopilema nomurai on the Silkworm Bombyx mori L.

    PubMed

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

    2015-10-01

    The silkworm Bombyx mori L. (B. mori) has a significant impact on the economy by producing more than 80% of the globally produced raw silk. The exposure of silkworm to pesticides may cause adverse effects on B. mori, such as a reduction in the production and quality of silk. This study aims to assay the effect of venom from the jellyfish Nemopilema nomurai on growth, cuticle and acetylcholinesterase (AChE) activity of the silkworm B. mori by the leaf dipping method. The experimental results revealed that the four samples caused neither antifeeding nor a lethal effect on B. mori. The sample SFV inhibited B. mori growth after 6 days of treatment in a dose-dependent manner. The samples SFV, DSFV and Fr-1 inhibited the precipitation and synthesis of chitin in the cuticle after 12 and 14 days of treatment. In the case of the four samples, the AChE was significantly improved after 14 days of treatment. PMID:26404374

  6. 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.

  7. Local versus Generalized Phenotypes in Two Sympatric Aurelia Species: Understanding Jellyfish Ecology Using Genetics and Morphometrics.

    PubMed

    Chiaverano, Luciano M; Bayha, Keith W; Graham, William M

    2016-01-01

    For individuals living in environmentally heterogeneous environments, a key component for adaptation and persistence is the extent of phenotypic differentiation in response to local environmental conditions. In order to determine the extent of environmentally induced morphological variation in a natural population distributed along environmental gradients, it is necessary to account for potential genetic differences contributing to morphological differentiation. In this study, we set out to quantify geographic morphological variation in the moon jellyfish Aurelia exposed at the extremes of a latitudinal environmental gradient in the Gulf of Mexico (GoM). We used morphological data based on 28 characters, and genetic data taken from mitochondrial cytochrome oxidase I (COI) and nuclear internal transcribed spacer 1 (ITS-1). Molecular analyses revealed the presence of two genetically distinct species of Aurelia co-occurring in the GoM: Aurelia sp. 9 and Aurelia c.f. sp. 2, named for its divergence from (for COI) and similarity to (for ITS-1) Aurelia sp. 2 (Brazil). Neither species exhibited significant population genetic structure between the Northern and the Southeastern Gulf of Mexico; however, they differed greatly in the degree of geographic morphological variation. The morphology of Aurelia sp. 9 exhibited ecophenotypic plasticity and varied significantly between locations, while morphology of Aurelia c.f. sp. 2 was geographically invariant (i.e., canalized). The plastic, generalist medusae of Aurelia sp. 9 are likely able to produce environmentally-induced, "optimal" phenotypes that confer high relative fitness in different environments. In contrast, the non-plastic generalist individuals of Aurelia c.f. sp. 2 likely produce environmentally-independent phenotypes that provide the highest fitness across environments. These findings suggest the two Aurelia lineages co-occurring in the GoM were likely exposed to different past environmental conditions (i

  8. Aurelin, a novel antimicrobial peptide from jellyfish Aurelia aurita with structural features of defensins and channel-blocking toxins.

    PubMed

    Ovchinnikova, Tatiana V; Balandin, Sergey V; Aleshina, Galina M; Tagaev, Andrey A; Leonova, Yulia F; Krasnodembsky, Eugeny D; Men'shenin, Alexander V; Kokryakov, Vladimir N

    2006-09-22

    A novel 40-residue antimicrobial peptide, aurelin, exhibiting activity against Gram-positive and Gram-negative bacteria, was purified from the mesoglea of a scyphoid jellyfish Aurelia aurita by preparative gel electrophoresis and RP-HPLC. Molecular mass (4296.95 Da) and complete amino acid sequence of aurelin (AACSDRAHGHICESFKSFCKDSGRNGVKLRANCKKTCGLC) were determined. Aurelin has six cysteines forming three disulfide bonds. The total RNA was isolated from the jellyfish mesoglea, RT-PCR and cloning were performed, and cDNA was sequenced. A 84-residue preproaurelin contains a putative signal peptide (22 amino acids) and a propiece of the same size (22 amino acids). Aurelin has no structural homology with any previously identified antimicrobial peptides but reveals partial similarity both with defensins and K+ channel-blocking toxins of sea anemones and belongs to ShKT domain family. PMID:16890198

  9. Flow structure and transport characteristics of feeding and exchange currents generated by upside-down Cassiopea jellyfish.

    PubMed

    Santhanakrishnan, Arvind; Dollinger, Makani; Hamlet, Christina L; Colin, Sean P; Miller, Laura A

    2012-07-15

    Quantifying the flows generated by the pulsations of jellyfish bells is crucial for understanding the mechanics and efficiency of their swimming and feeding. Recent experimental and theoretical work has focused on the dynamics of vortices in the wakes of swimming jellyfish with relatively simple oral arms and tentacles. The significance of bell pulsations for generating feeding currents through elaborate oral arms and the consequences for particle capture are not as well understood. To isolate the generation of feeding currents from swimming, the pulsing kinematics and fluid flow around the benthic jellyfish Cassiopea spp. were investigated using a combination of videography, digital particle image velocimetry and direct numerical simulation. During the rapid contraction phase of the bell, fluid is pulled into a starting vortex ring that translates through the oral arms with peak velocities that can be of the order of 10 cm s(-1). Strong shear flows are also generated across the top of the oral arms throughout the entire pulse cycle. A coherent train of vortex rings is not observed, unlike in the case of swimming oblate medusae such as Aurelia aurita. The phase-averaged flow generated by bell pulsations is similar to a vertical jet, with induced flow velocities averaged over the cycle of the order of 1-10 mm s(-1). This introduces a strong near-horizontal entrainment of the fluid along the substrate and towards the oral arms. Continual flow along the substrate towards the jellyfish is reproduced by numerical simulations that model the oral arms as a porous Brinkman layer of finite thickness. This two-dimensional numerical model does not, however, capture the far-field flow above the medusa, suggesting that either the three-dimensionality or the complex structure of the oral arms helps to direct flow towards the central axis and up and away from the animal. PMID:22723475

  10. pH-responsive inorganic-organic hybrid supramolecular hydrogels with jellyfish-like switchable chromic luminescence.

    PubMed

    Wei, Haibing; Shi, Nan; Zhang, Jinlong; Guan, Yan; Zhang, Jie; Wan, Xinhua

    2014-08-25

    A unique type of novel supramolecular hybrid hydrogel based on the co-assembly of the anionic polyoxometalate and the cationic ABA triblock copolymer via electrostatic interaction was reported to show jellyfish-like switchable chromic luminescence. The hydrogel undergoes reversible sol-gel transition in response to pH changes, and simultaneously exhibits an unprecedented luminescent chromism from weak green to strong white. PMID:25001843

  11. Diversity, Phylogeny and Expression Patterns of Pou and Six Homeodomain Transcription Factors in Hydrozoan Jellyfish Craspedacusta sowerbyi

    PubMed Central

    Hroudova, Miluse; Vojta, Petr; Strnad, Hynek; Krejcik, Zdenek; Ridl, Jakub; Paces, Jan; Vlcek, Cestmir; Paces, Vaclav

    2012-01-01

    Formation of all metazoan bodies is controlled by a group of selector genes including homeobox genes, highly conserved across the entire animal kingdom. The homeobox genes from Pou and Six classes are key members of the regulation cascades determining development of sensory organs, nervous system, gonads and muscles. Besides using common bilaterian models, more attention has recently been targeted at the identification and characterization of these genes within the basal metazoan phyla. Cnidaria as a diploblastic sister group to bilateria with simple and yet specialized organs are suitable models for studies on the sensory organ origin and the associated role of homeobox genes. In this work, Pou and Six homeobox genes, together with a broad range of other sensory-specific transcription factors, were identified in the transcriptome of hydrozoan jellyfish Craspedacusta sowerbyi. Phylogenetic analyses of Pou and Six proteins revealed cnidarian-specific sequence motifs and contributed to the classification of individual factors. The majority of the Craspedacusta sowerbyi Pou and Six homeobox genes are predominantly expressed in statocysts, manubrium and nerve ring, the tissues with sensory and nervous activities. The described diversity and expression patterns of Pou and Six factors in hydrozoan jellyfish highlight their evolutionarily conserved functions. This study extends the knowledge of the cnidarian genome complexity and shows that the transcriptome of hydrozoan jellyfish is generally rich in homeodomain transcription factors employed in the regulation of sensory and nervous functions. PMID:22558464

  12. Diversity, phylogeny and expression patterns of Pou and Six homeodomain transcription factors in hydrozoan jellyfish Craspedacusta sowerbyi.

    PubMed

    Hroudova, Miluse; Vojta, Petr; Strnad, Hynek; Krejcik, Zdenek; Ridl, Jakub; Paces, Jan; Vlcek, Cestmir; Paces, Vaclav

    2012-01-01

    Formation of all metazoan bodies is controlled by a group of selector genes including homeobox genes, highly conserved across the entire animal kingdom. The homeobox genes from Pou and Six classes are key members of the regulation cascades determining development of sensory organs, nervous system, gonads and muscles. Besides using common bilaterian models, more attention has recently been targeted at the identification and characterization of these genes within the basal metazoan phyla. Cnidaria as a diploblastic sister group to bilateria with simple and yet specialized organs are suitable models for studies on the sensory organ origin and the associated role of homeobox genes. In this work, Pou and Six homeobox genes, together with a broad range of other sensory-specific transcription factors, were identified in the transcriptome of hydrozoan jellyfish Craspedacusta sowerbyi. Phylogenetic analyses of Pou and Six proteins revealed cnidarian-specific sequence motifs and contributed to the classification of individual factors. The majority of the Craspedacusta sowerbyi Pou and Six homeobox genes are predominantly expressed in statocysts, manubrium and nerve ring, the tissues with sensory and nervous activities. The described diversity and expression patterns of Pou and Six factors in hydrozoan jellyfish highlight their evolutionarily conserved functions. This study extends the knowledge of the cnidarian genome complexity and shows that the transcriptome of hydrozoan jellyfish is generally rich in homeodomain transcription factors employed in the regulation of sensory and nervous functions. PMID:22558464

  13. Modulation of jellyfish nematocyst discharges and management of human skin stings in Nemopilema nomurai and Carybdea mora.

    PubMed

    Pyo, Min-Jung; Lee, Hyunkyoung; Bae, Seong Kyong; Heo, Yunwi; Choudhary, Indu; Yoon, Won Duk; Kang, Changkeun; Kim, Euikyung

    2016-01-01

    Even though jellyfish sting is common today, its first aid guideline has never been clear enough in a scientific point of view and the use of vinegar appears to be not accepted in common throughout the world. In the present study, to develop rational first aid guidelines for the stings of Nemopilema nomurai (scyphozoa) and Carybdea mora (cubozoa), the modulatory effects of various kinds of rinsing solutions have been assessed on nematocyst discharge and human skin tests. Among the solutions tested, vinegar (4% acetic acid) immediately caused significant nematocyst discharge in N. nomurai but not in C. mora. On the other hand, ethanol (70%) notably stimulated nematocyst discharge in C. mora and relatively less in N. nomurai. Moreover, isopropanol, a widely used solvent in pharmaceutical products, caused extensive nematocyst discharges in both N. nomurai and C. mora. Whereas, seawater did not elicit any nematocyst discharge in both jellyfish species. In human skin test, the rinsing with seawater also ameliorated the stinging-associated symptoms (pain and redness) in C. mora as well as N. nomurai. From this study, seawater appears not to induce any nematocyst discharge and can be safely used as a first aid rinsing solution for the jellyfish stings. PMID:26541574

  14. A method for eradicating amphipod parasites (hyperiidae) from host jellyfish, Chrysaora fuscescens (Brandt, 1835), in a closed recirculating system.

    PubMed

    Crossley, Sharyl M G; George, Anna L; Keller, Christian J

    2009-03-01

    On 2 December 2006, a heavy infestation of the parasitic hyperiid amphipods Hyperia medusarum and Lestrigonus shoemakeri was discovered in the sea nettles (Chrysaora fuscescens) exhibit at the Tennessee Aquarium. Pretreatment trials that exposed moon jellyfish (Aurelia aurita) and sea nettles to therapeutic levels of diflubenzuron confirmed that the treatment would be tolerated by these species of jellyfish. The exhibit tank was dosed with a 0.03 mg/L concentration of diflubenzuron for 7 days, after which the medication was removed by filtration. An arbitrarily chosen subset from the sea nettle exhibit was sampled regularly over the next 8 wk to monitor the parasite population. The average number of amphipods per jellyfish sampled decreased throughout the treatment and sampling period. No live amphipods were observed 6 wk after the start of treatment, and no negative side effects were observed in the sea nettles. The use of diflubenzuron to eradicate hyperiid parasites from scyphomedusae is a safe and useful option when properly applied in a controlled environment. PMID:19368258

  15. Design and development of bio-inspired underwater jellyfish like robot using ionic polymer metal composite (IPMC) actuators

    NASA Astrophysics Data System (ADS)

    Akle, Barbar; Najem, Joseph; Leo, Donald; Blottman, John

    2011-04-01

    This study presents the design and development of an underwater Jellyfish like robot using Ionic Polymer Metal Composites (IPMCs) as propulsion actuators. For this purpose, IPMCs are manufactured in several variations. First the electrode architecture is controlled to optimize the strain, strain rate, and stiffness of the actuator. Second, the incorporated diluents species are varied. The studied diluents are water, formamide, and 1-ethyl-3-methyimidazolium trifluoromethanesulfonate (EmI-Tf) ionic liquid. A water based IPMC demonstrates a fast strain rate of 1%/s, but small peak strain of 0.3%, and high current of 200mA/cm2, as compared to an IL based IPMC which has a slow strain rate of 0.1%/s, large strain of 3%, and small current of 50mA/cm2. The formamide is proved to be the most powerful with a strain rate of approximately 1%/s, peak strain larger than 5%, and a current of 150mA/cm2. The IL and formamide based samples required encapsulation for shielding the diluents from being dissolved in the surrounding water. Two Jellyfish like robots are developed each with an actuator with different diluents. Several parameters on the robot are optimized, such as the input waveform to the actuators, the shape and material of the belly. The finesse ratio of the shape of the robotic belly is compared with biological jellyfish such as the Aurelia-Aurita..

  16. Plastic Jellyfish.

    ERIC Educational Resources Information Center

    Moseley, Christine

    2000-01-01

    Presents an environmental science activity designed to enhance students' awareness of the hazards of plastic waste for wildlife in aquatic environments. Discusses how students can take steps to reduce the effects of plastic waste. (WRM)

  17. Jellyfish stings

    MedlinePlus

    ... www.ncbi.nlm.nih.gov/pubmed/21824077 . Yanagihara AA, Wilcox C, King R, Hurwitz K, Castelfranco AM. ... www.ncbi.nlm.nih.gov/pubmed/26761033 . Yanagihara AA, Wilcox C, Smith J, Surrett GW. Cubozoan envenomations: ...

  18. Local versus Generalized Phenotypes in Two Sympatric Aurelia Species: Understanding Jellyfish Ecology Using Genetics and Morphometrics

    PubMed Central

    Chiaverano, Luciano M.; Bayha, Keith W.; Graham, William M.

    2016-01-01

    For individuals living in environmentally heterogeneous environments, a key component for adaptation and persistence is the extent of phenotypic differentiation in response to local environmental conditions. In order to determine the extent of environmentally induced morphological variation in a natural population distributed along environmental gradients, it is necessary to account for potential genetic differences contributing to morphological differentiation. In this study, we set out to quantify geographic morphological variation in the moon jellyfish Aurelia exposed at the extremes of a latitudinal environmental gradient in the Gulf of Mexico (GoM). We used morphological data based on 28 characters, and genetic data taken from mitochondrial cytochrome oxidase I (COI) and nuclear internal transcribed spacer 1 (ITS-1). Molecular analyses revealed the presence of two genetically distinct species of Aurelia co-occurring in the GoM: Aurelia sp. 9 and Aurelia c.f. sp. 2, named for its divergence from (for COI) and similarity to (for ITS-1) Aurelia sp. 2 (Brazil). Neither species exhibited significant population genetic structure between the Northern and the Southeastern Gulf of Mexico; however, they differed greatly in the degree of geographic morphological variation. The morphology of Aurelia sp. 9 exhibited ecophenotypic plasticity and varied significantly between locations, while morphology of Aurelia c.f. sp. 2 was geographically invariant (i.e., canalized). The plastic, generalist medusae of Aurelia sp. 9 are likely able to produce environmentally-induced, “optimal” phenotypes that confer high relative fitness in different environments. In contrast, the non-plastic generalist individuals of Aurelia c.f. sp. 2 likely produce environmentally-independent phenotypes that provide the highest fitness across environments. These findings suggest the two Aurelia lineages co-occurring in the GoM were likely exposed to different past environmental conditions (i

  19. 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

  20. A specific antimicrobial protein CAP-1 from Pseudomonas sp. isolated from the jellyfish Cyanea capillata.

    PubMed

    Yin, Manman; Liu, Dan; Xu, Feng; Xiao, Liang; Wang, Qianqian; Wang, Beilei; Chang, Yinlong; Zheng, Jiemin; Tao, Xia; Liu, Guoyan; Zhang, Liming

    2016-01-01

    A bacterium strain, designated as CMF-2, was isolated from the jellyfish Cyanea capillata and its culture supernatant exhibited a significant antimicrobial activity. The strain CMF-2 was identified as Pseudomonas sp. based on the morphological, biochemical and physiological characteristics as well as 16S rRNA sequence analysis. In this study, an antimicrobial protein, named as CAP-1, was isolated from the culture of CMF-2 through ammonium sulfate precipitation and gel filtration chromatography. According to the result of sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), a major band indicated that the antimicrobial protein had a molecular mass of about 15 kDa, and it was identified as a hypothetical protein by MALDI-TOF-MS analysis and Mascot searching. CAP-1 displayed a broad antimicrobial spectrum against the indicator bacteria and fungus, including Staphylococcus aureus, Escherichia coli, Bacillus subtilis and Candida albicans, especially some marine-derived microorganisms such as Vibrio vulnificus, Vibrio alginolyticus, Vibrio parahaemolyticus, Vibrio cholera, and Vibrio anguillarum, but showed little impact on tumor cells and normal human cells. The protein CAP-1 remained a stable antimicrobial activity in a wide range of temperature (20-80°C) and pH (2-10) conditions. These results suggested that CAP-1 might have a specific antimicrobial function not due to cytotoxicity. PMID:26529191

  1. Flow patterns generated by oblate medusan jellyfish: field measurements and laboratory analyses.

    PubMed

    Dabiri, John O; Colin, Sean P; Costello, John H; Gharib, Morteza

    2005-04-01

    Flow patterns generated by medusan swimmers such as jellyfish are known to differ according the morphology of the various animal species. Oblate medusae have been previously observed to generate vortex ring structures during the propulsive cycle. Owing to the inherent physical coupling between locomotor and feeding structures in these animals, the dynamics of vortex ring formation must be robustly tuned to facilitate effective functioning of both systems. To understand how this is achieved, we employed dye visualization techniques on scyphomedusae (Aurelia aurita) observed swimming in their natural marine habitat. The flow created during each propulsive cycle consists of a toroidal starting vortex formed during the power swimming stroke, followed by a stopping vortex of opposite rotational sense generated during the recovery stroke. These two vortices merge in a laterally oriented vortex superstructure that induces flow both toward the subumbrellar feeding surfaces and downstream. The lateral vortex motif discovered here appears to be critical to the dual function of the medusa bell as a flow source for feeding and propulsion. Furthermore, vortices in the animal wake have a greater volume and closer spacing than predicted by prevailing models of medusan swimming. These effects are shown to be advantageous for feeding and swimming performance, and are an important consequence of vortex interactions that have been previously neglected. PMID:15781886

  2. Recombinant expression and solution structure of antimicrobial peptide aurelin from jellyfish Aurelia aurita.

    PubMed

    Shenkarev, Zakhar O; Panteleev, Pavel V; Balandin, Sergey V; Gizatullina, Albina K; Altukhov, Dmitry A; Finkina, Ekaterina I; Kokryakov, Vladimir N; Arseniev, Alexander S; Ovchinnikova, Tatiana V

    2012-12-01

    Aurelin is a 40-residue cationic antimicrobial peptide isolated from the mezoglea of a scyphoid jellyfish Aurelia aurita. Aurelin and its (15)N-labeled analogue were overexpressed in Escherichia coli and purified. Antimicrobial activity of the recombinant peptide was examined, and its spatial structure was studied by NMR spectroscopy. Aurelin represents a compact globule, enclosing one 3(10)-helix and two α-helical regions cross-linked by three disulfide bonds. The peptide binds to anionic lipid (POPC/DOPG, 3:1) vesicles even at physiological salt concentration, it does not interact with zwitterionic (POPC) vesicles and interacts with the DPC micelle surface with moderate affinity via two α-helical regions. Although aurelin shows structural homology to the BgK and ShK toxins of sea anemones, its surface does not possess the "functional dyad" required for the high-affinity interaction with the K(+)-channels. The obtained data permit to correlate the modest antibacterial properties and membrane activity of aurelin. PMID:23137541

  3. Phenotypic plasticity in juvenile jellyfish medusae facilitates effective animal-fluid interaction.

    PubMed

    Nawroth, J C; Feitl, K E; Colin, S P; Costello, J H; Dabiri, J O

    2010-06-23

    Locomotion and feeding in marine animals are intimately linked to the flow dynamics created by specialized body parts. This interaction is of particular importance during ontogeny, when changes in behaviour and scale challenge the organism with shifts in fluid regimes and altered functionality. Previous studies have indicated that Scyphozoan jellyfish ontogeny accommodates the changes in fluid dynamics associated with increasing body dimensions and velocities during development. However, in addition to scale and behaviour that-to a certain degree-underlie the control of the animal, flow dynamics are also dependent on external factors such as temperature. Here, we show phenotypic plasticity in juvenile Aurelia aurita medusae, where morphogenesis is adapted to altered fluid regimes imposed by changes in ambient temperature. In particular, differential proportional growth was found to compensate for temperature-dependent changes in viscous effects, enabling the animal to use adhering water boundary layers as 'paddles'-and thus economize tissue-at low temperatures, while switching to tissue-dominated propulsion at higher temperatures where the boundary layer thickness is insufficient to serve for paddling. This effect was predicted by a model of animal-fluid interaction and confirmed empirically by flow-field visualization and assays of propulsion efficiency. PMID:20335200

  4. Jellyfish skin polysaccharides: extraction and inhibitory activity on macrophage-derived foam cell formation.

    PubMed

    Zhang, Hai-Lin; Cui, Shao-Hua; Zha, Xue-Qiang; Bansal, Vibha; Xue, Lei; Li, Xiao-Long; Hao, Ran; Pan, Li-Hua; Luo, Jian-Ping

    2014-06-15

    In this work, response surface methodology was used to determine optimum conditions for extraction of polysaccharides from jellyfish skin (JSP). The optimum parameters were found to be raw material to water ratio 1:7.5 (w/v), extraction temperature 100°C and extraction time 4h. Under these conditions, the JSP yield reached 1.007 mg/g. Papain (15 U/mL) in combination with Sevag reagent was beneficial in removing proteins from JSP. After precipitation with ethanol at final concentration of 40%, 60% and 80% in turn, three polysaccharide fractions of JSP1, JSP2 and JSP3 were obtained from JSP, respectively. The three fractions exhibited different physicochemical properties with respect to molecular weight distribution, monosaccharide composition, infrared absorption spectra, and glycosyl bond composition. In addition, JSP3 showed strong inhibitory effects on oxidized low-density lipoprotein (oxLDL) induced conversion of macrophages into foam cells, which possibly attributed to the down-regulation of some atherogenesis-related gene expressions. PMID:24721094

  5. Heavy metals affect regulatory volume decrease (RVD) in nematocytes isolated from the jellyfish Pelagia noctiluca.

    PubMed

    Morabito, R; Marino, A; La Spada, G

    2013-06-01

    The environmental contamination caused by heavy metals raises the question of their effect on biological systems. Among bio-indicators useful to monitor the toxicological effects of these chemicals, Cnidarians offer a unique model. Cnidarians possess highly specialized stinging cells, termed nematocytes, which respond to hyposmotic solution with well established homeostatic parameters as an acute osmotic phase (OP), leading to cell swelling, and then a slower regulatory volume decrease (RVD) phase, causing cell shrinkage. Here we report the effect of 65% artificial sea water (ASW) containing heavy metals, such as Cd, La, Co, Cu and Zn (concentrations comprised between 100 and 0.1 μM) on both OP and RVD in nematocytes isolated from the jellyfish Pelagia noctiluca by 605 mM NaSCN plus 0.01 mM Ca(2+). The exposure of the cells to Co and La inhibited RVD but not OP. However, Cu, Cd and Zn prevented the OP in a dose-dependent manner and, hence, also the detection of RVD. These results suggest that, in isolated nematocytes, heavy metal pollutants impair RVD either directly or indirectly through interference with the OP, thus negating RVD. Although further studies need to clarify the exact mechanisms whereby heavy metals exert their toxicity, it is evident that nematocytes of Cnidarians could serve as a model for ecotoxicological investigations. PMID:23499922

  6. Jellyfish: Special Tools for Biological Research on Earth and in Space

    NASA Technical Reports Server (NTRS)

    Spangenberg, Dorothy B.

    1991-01-01

    The most intriguing nature of the jellyfish polyps is their ability to metamorphose, giving rise to tiny immature medusae called ephyrae which have a different form or shape from the polyps. The Aurelia Metamorphosis Test System was used to determine the subtle effects of hydrocarbons found in oil spills and the effects of X-irradiation on developing ephyrae. Currently, this test system is used to determine the effects of the gravity-less environment of outer space on the development and behavior of ephyrae. For this purpose, the effects of clinostat rotation on development of the ephyrae and their gravity receptor are being studied. The behavior of the ephyrae during 0 gravity achieved for short intervals of 30 seconds in parabolic flight is examined. The developing ephyrae and the mature ephyrae are exposed to gravity-less environment of outer space via a six or seven day shuttle experiment. If gravity receptors do form in outer space, they will be studied in detail using various types of microscopes, including the electron microscope, to determin whether they developed normally in space as compared with control on Earth.

  7. Analgesic and antibutyrylcholinestrasic activities of the venom prepared from the Mediterranean jellyfish Pelagia noctiluca (Forsskal, 1775)

    PubMed Central

    2012-01-01

    Background Toxins derived from jellyfishes have been exploited as a model for the development of new drug promising applications to treat neurodegenerative diseases. The present work is aimed to evaluate the acute toxicity of crude venom of Pelagia noctiluca and then to screen the analgesic and antibutyrylcholinestrasic (anti-BuChE) activities of the crude venom and its fractions. Methods Sephadex G75 gel was used to separate crude venom of Pelagia noctiluca, which led to some fractions. In addition, in vivo analgesic and in vitro plasma antibutyrylcholinestrasic activities were carried out with Pelagia crude venom and its fractions respectively. Results The crude venom and its fractions displayed analgesic and anti-BuChE activities at different doses without inducing acute toxicity. Fraction 2 possesses the highest analgesic and antibutyrylcholinestrasic properties. The crude venom and fraction 1 had shown to possess less significant inhibitory activity against analgesic and antibutyrylcholinestrasic models. Conclusions Based on this study, the crude venom of Pelagia noctiluca is found to be a useful tool for probing pharmacological activity. The purification and the determination of chemical structures of compounds of active fractions of the venom are under investigation. PMID:22691546

  8. Construction of chitin/PVA composite hydrogels with jellyfish gel-like structure and their biocompatibility.

    PubMed

    He, Meng; Wang, Zhenggang; Cao, Yan; Zhao, Yanteng; Duan, Bo; Chen, Yun; Xu, Min; Zhang, Lina

    2014-09-01

    High strength chitin/poly(vinyl alcohol) (PVA) composite hydrogels (RCP) were constructed by adding PVA into chitin dissolved in a NaOH/urea aqueous solution, and then by cross-linking with epichlorohydrin (ECH) and freezing-thawing process. The RCP hydrogels were characterized by field emission scanning electron microscopy, FTIR, differential scanning calorimetry, solid-state (13)C NMR, wide-angle X-ray diffraction, and compressive test. The results revealed that the repeated freezing/thawing cycles induced the bicrosslinked networks consisted of chitin and PVA crystals in the composite gels. Interestingly, a jellyfish gel-like structure occurred in the RCP75 gel with 25 wt % PVA content in which the amorphous and crystalline PVA were immobilized tightly in the chitin matrix through hydrogen bonding interaction. The freezing/thawing cycles played an important role in the formation of the layered porous PVA networks and the tight combining of PVA with the pore wall of chitin. The mechanical properties of RCP75 were much higher than the other RCP gels, and the compressive strength was 20× higher than that of pure chitin gels, as a result of broadly dispersing stress caused by the orderly multilayered networks. Furthermore, the cell culture tests indicated that the chitin/PVA composite hydrogels exhibited excellent biocompatibility and safety, showing potential applications in the field of tissue engineering. PMID:25077674

  9. Clearance rates of ephyrae and small medusae of the common jellyfish Aurelia aurita offered different types of prey

    NASA Astrophysics Data System (ADS)

    Riisgård, Hans Ulrik; Madsen, Caroline V.

    2011-01-01

    Prey selection and knowledge of the amounts of water processed by the early stages of the common jellyfish Aurelia aurita may at certain times of the year be crucial for understanding the plankton dynamics in marine ecosystems with mass occurrences of this jellyfish. In the present study we used two different methods ("clearance method" and "ingestion-rate method") to estimate the amount of water cleared per unit of time of different types and sizes of prey organisms offered to A. aurita ephyrae and small medusae. The mean clearance rates of medusae, estimated with Artemia sp. nauplii as prey by both methods, agreed well, namely 3.8 ± 1.4 l h - 1 by the clearance method and 3.2 ± 1.1 l h - 1 by the ingestion-rate method. Both methods showed that copepods (nauplii and adults) and mussel veligers are captured with considerably lower efficiency, 22 to 37% and 14 to 30%, respectively, than Artemia salina nauplii. By contrast, the water processing rates of ephyrae measured by the clearance method with A. salina nauplii as prey were 3 to 5 times lower than those measured by the ingestion-rate method. This indicates that the prerequisite of full mixing for using the clearance method may not have been fulfilled in the ephyrae experiments. The study demonstrates that the predation impact of the young stages of A. aurita is strongly dependent on its developmental stage (ephyra versus medusa), and the types and sizes of prey organisms. The estimated prey-digestion time of 1.3 h in a steady-state feeding experiment with constant prey concentration supports the reliability of the ingestion-rate method, which eliminates the negative "container effects" of the clearance method, and it seems to be useful in future jellyfish studies, especially on small species/younger stages in which both type and number of prey can be easily and precisely assessed.

  10. Paecilonic acids A and B, bicyclic fatty acids from the jellyfish-derived fungus Paecilomyces variotii J08NF-1.

    PubMed

    Wang, Haibo; Hong, Jongki; Yin, Jun; Liu, Juan; Liu, Yonghong; Choi, Jae Sue; Jung, Jee H

    2016-05-01

    Two new bicyclic fatty acids, paecilonic acids A and B (1 and 2), were isolated from the culture broth of the marine fungus Paecilomyces variotii derived from the jellyfish Nemopilema nomurai. Compounds 1 and 2 share the same molecular formula and possess a 6,8-dioxabicyclo[3.2.1]octane core skeleton. The planar structures of compounds 1 and 2 were established by spectroscopic analysis, which included NMR and ESI-MS/MS. Relative and absolute configurations were determined by analyzing coupling constants, NOESY correlations, and optical rotations. PMID:27009897

  11. 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

  12. Recombinant expression and solution structure of antimicrobial peptide aurelin from jellyfish Aurelia aurita

    SciTech Connect

    Shenkarev, Zakhar O.; Panteleev, Pavel V.; Balandin, Sergey V.; Finkina, Ekaterina I.; Arseniev, Alexander S.; Ovchinnikova, Tatiana V.

    2012-12-07

    Highlights: Black-Right-Pointing-Pointer Aurelin was overexpressed in Escherichia coli, and its spatial structure was studied by NMR. Black-Right-Pointing-Pointer Aurelin compact structure encloses helical regions cross-linked by three disulfide bonds. Black-Right-Pointing-Pointer Aurelin shows structural homology to the BgK and ShK toxins of sea anemones. Black-Right-Pointing-Pointer Aurelin binds to the anionic lipid vesicles, but does not interact with zwitterionic ones. Black-Right-Pointing-Pointer Aurelin binds to DPC micelle surface with moderate affinity via two helical regions. -- Abstract: Aurelin is a 40-residue cationic antimicrobial peptide isolated from the mezoglea of a scyphoid jellyfish Aurelia aurita. Aurelin and its {sup 15}N-labeled analogue were overexpressed in Escherichia coli and purified. Antimicrobial activity of the recombinant peptide was examined, and its spatial structure was studied by NMR spectroscopy. Aurelin represents a compact globule, enclosing one 3{sub 10}-helix and two {alpha}-helical regions cross-linked by three disulfide bonds. The peptide binds to anionic lipid (POPC/DOPG, 3:1) vesicles even at physiological salt concentration, it does not interact with zwitterionic (POPC) vesicles and interacts with the DPC micelle surface with moderate affinity via two {alpha}-helical regions. Although aurelin shows structural homology to the BgK and ShK toxins of sea anemones, its surface does not possess the 'functional dyad' required for the high-affinity interaction with the K{sup +}-channels. The obtained data permit to correlate the modest antibacterial properties and membrane activity of aurelin.

  13. Jellyfish Lake, Palau: Regeneration of C, N, Si, and P in anoxic marine lake sediments

    USGS Publications Warehouse

    Lyons, W.B.; Lent, R.M.; Burnett, W.C.; Chin, P.; Landing, W.M.; Orem, W.H.; McArthur, J.M.

    1996-01-01

    Sediment cores from Jellyfish Lake were processed under an inert atmosphere and the pore waters extracted and analyzed for the following parameters: pH, titration alkalinity (TA), Cl-, H4SiO4, PO43-, NH4+, Ca2-, Mg2+, SO42-, and H2S. Additionally, in one set of pore-water samples (core 10), the ??13C of the ??CO2 was also determined. The TA, H4SiO4, PO43-, NH4+, and H2S increased with depth in the pore waters above anoxic bottom-water values. H2S values increased to 3.8 ??M. In one case, both H4SiO4 and PO43- concentrations increased to a maximum value and then decreased with depth, suggesting removal into solid phases. The H4SiO4 concentrations are equal to or greater than pore-water values observed in sediments underlying upwelling areas. PO43- concentrations are, in general, lower than pore-water values from terrigenous nearshore areas but higher than nearshore carbonate pore-water values from Florida Bay or Bermuda. The Ca2+, Cl-, and Mg2+: Cl- ratios show slight decreases in the top 15-20 cm, suggesting that authigenic carbonate may be forming. This suggestion is supported by the fact that the pore waters are saturated with respect to CaCO3 due to the very high TAs. The ??13C measurements of the pore-water ??CO2 are from a shorter core. These measurements reach their most negative concentration at 72 cm and then become slightly heavier. This change is accompanied by a decrease in TA, suggesting the onset of methanogenesis at this location in this core.

  14. Epidemiology of Jellyfish Stings Presented to an American Urban Emergency Department

    PubMed Central

    Onizuka, Neil

    2011-01-01

    Introduction Cnidarian, or jellyfifish, stings are a common malady in tropical Emergency Departments. There are limited studies examining cnidarian stings in the United States. The team investigated the epidemiology and treatments for jellyfish stings presenting to an urban emergency department (ED) in Honolulu, Hawai‘i. Methods The team performed a retrospective chart analysis of stings presented between 2000 and 2008. A total of 116 patients were identified. Charts were reviewed for patient demographics, incident characteristics, patient arrival condition, and treatments given in the emergency department. Results The median age was 24 years (range 9–85). Of patients 58% were men, 64% were Hawai‘i non-residents, and 23 % arrived between the hours of 10pm and 2 am. Emergency Medical System transported 64%, and 65% arrived with normal vital signs. Twenty-four different types of IV/PO medications were administered and patients received up to 5 different medications per visit. Intravenous medications were given to 64%. All patients were eventually discharged home from the ED. Discussion Risk factors for cnidarian stings include being men, being a Hawai‘i non-resident, and nighttime ocean activities. Stings were treated with various medications and routes suggesting that there is no current standard of care for stings. This study suggests that there is a need for public health interventions tailored to tourists. Prevention and education of home treatment could decrease the cost of health care by decreasing ambulance transports and total number of ED visits for a non-urgent disease. PMID:22162597

  15. Evidence for aquaporin-mediated water transport in nematocytes of the jellyfish Pelagia noctiluca.

    PubMed

    Marino, Angela; Morabito, Rossana; La Spada, Giuseppina; Adragna, Norma C; Lauf, Peter K

    2011-01-01

    Nematocytes, the stinging cells of Cnidarians, have a cytoplasm confined to a thin rim. The main cell body is occupied by an organoid, the nematocyst, containing the stinging tubule and venom. Exposed to hypotonic shock, nematocytes initially swell during an osmotic phase (OP) and then undergo regulatory volume decrease (RVD) driven by K(+), Cl(-) and obligatory water extrusion mechanisms. The purpose of this report is to characterize the OP. Nematocytes were isolated by the NaSCN/Ca(2+) method from tentacles of the jellyfish Pelagia noctiluca, collected in the Strait of Messina, Italy. Isolated nematocytes were subjected to hyposmotic shock in 65% artificial seawater (ASW) for 15 min. The selective aquaporin water channel inhibitor HgCl(2) (0.1-25 μM) applied prior to osmotic shock prevented the OP and thus RVD. These effects were attenuated in the presence of 1mM dithiothreitol (DTT), a mercaptide bond reducing agent. AgNO(3) (1 μM) and TEA (tetraethylammonium, 100 μM), also reported to inhibit water transport, did not alter the OP but significantly diminished RVD, suggesting different modes of action for the inhibitors tested. Based on estimates of the nematocyte surface area and volume, and OP duration, a relative water permeability of ~10(-7) cm/sec was calculated and the number of putative aquaporin molecules mediating the OP was estimated. This water permeability is 3-4 orders of magnitude lower in comparison to higher order animals and may constitute an evolutionary advantage for Cnidarian survival. PMID:22179009

  16. 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.

  17. 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

    2016-01-01

    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 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. PMID:27399771

  18. New family of allomorphic jellyfishes, Drymonematidae (Scyphozoa, Discomedusae), emphasizes evolution in the functional morphology and trophic ecology of gelatinous zooplankton.

    PubMed

    Bayha, Keith M; Dawson, Michael N

    2010-12-01

    Molecular analyses have revealed many cryptic species in the oceans, often permitting small morphological differences to be recognized as diagnosing species, but less commonly leading to consideration of cryptic ecology. Here, based on analyses of three nuclear DNA sequence markers (ribosomal 18S, 28S, and internal transcribed spacer 1 [ITS1]), two mitochondrial DNA markers (cytochrome c oxidase subunit I [COI] and ribosomal 16S), and 55 morphological features, we revise the classification of the enigmatic jellyfish genus Drymonema. We describe a new scyphozoan family, Drymonematidae, elevating the previous subfamily Drymonemidae to accommodate three species: the type species D. dalmatinum from the Mediterranean region, for which we identify a neotype; the western South Atlantic species D. gorgo; and a new species, D. larsoni from the western Atlantic and Caribbean, which also is described here. This revision emphasizes the remarkable morphological disparity of Drymonematidae from all other scyphomedusae, including allometric growth of the bell margin distal of the rhopalia, an annular zone of tentacles on the subumbrella, and ontogenetic loss of gastric filaments. Anatomical innovations are likely functionally related to predatory specialization on large gelatinous zooplankton, most notably the phylogenetically younger moon jellyfish Aurelia, indicating evolution of the feeding niche in Drymonematidae. This family-level revision contributes to the growing body of evidence that scyphomedusae are far more taxonomically rich, their biogeography is a more detailed mosaic, and their phenotypes are more nuanced than traditionally thought. Ecological and evolutionary responses to environmental change, past or future, are likely to be commensurately diverse. PMID:21183445

  19. Macrobenthic community structure and species composition in the Yellow Sea and East China Sea in jellyfish bloom

    NASA Astrophysics Data System (ADS)

    Peng, Songyao; Li, Xinzheng; Wang, Hongfa; Zhang, Baolin

    2014-05-01

    To understand the characteristics of macrobenthic structures and the relationship between environment and benthic assemblages in jellyfish bloom, we studied the macrobenthos and related environmental factors in the coastal waters of the Yellow Sea and East China Sea. Data were collected during two seasonal cruises in April and August of 2011, and analyzed with multivariate statistical methods. Up to 306 macrobenthic species were registered from the research areas, including 115 species of Polychaeta, 78 of Crustacea, 61 of Mollusca, 30 of Echinodermata, and 22 of other groups. Nine polychaete species occurred at frequencies higher than 25% from the sampling stations: Lumbrineris longifolia, Notomastus latericeus, Ninöe palmata, Ophelina acuminata, Nephtys oligobranchia, Onuphis geophiliformis, Glycera chirori, Terebellides stroemii, and Aricidea fragilis. Both the average biomass and abundance of macrobenthos are higher in August (23.8 g/m2 and 237.7 ind./m2) than those in April (11.3 g/m2 and 128 ind./m2); the dissimilarity of macrobenthic structures among stations is as high as 70%. In terms of the dissimilarity values, we divided the stations into four clusters in spring and eight in summer. The ABC curve shows that the macrofauna communities in high jellyfish abundance were not changed. Canonical correspondence analysis showed that depth, temperature, median grain size, total organic carbon of sediment and total nitrogen in sediment were important factors affecting the macrozoobenthic community in the study area.

  20. 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.

  1. 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

  2. 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.

  3. 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. PMID:27169682

  4. 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

  5. Settlement of planulae of the Moon jellyfish Aurelia aurita onto hydrophilic polycarbonate plates modified by atmospheric plasma treatment.

    PubMed

    Tomaru, Akiko; Sasaki, Ryota; Miyahara, Hidekazu; Okino, Akitoshi; Ogawa, Nobuhiro; Hamasaki, Koji

    2014-01-01

    It has been reported that planula larvae of some jellyfish prefer artificial substrates for settlement. This research focused on the relationship between the settlement of planulae and the wettability of artificial substrate surfaces. We used atmospheric plasmas to change the wettability of the surfaces of polycarbonate (PC) plates because plasma treatment has no chemical side effects. The treatment made the surfaces hydrophilic, as evidenced by the decrease of contact angle from 85° to 35°. X-ray photoelectron spectroscopy revealed that the change of wettability of the PC plates could be attributed to N2, which was probably ionized in the air above the plates. Scanning electron microscopy revealed no difference in the surface morphology of the plates before and after plasma treatment. Results of bioassays using treated PC plates showed that planulae tended to preferentially settle on hydrophobic surfaces. PMID:24465603

  6. Noninvasive laser therapy in the treatment of keloid scar after injury caused by a jellyfish: a case report

    NASA Astrophysics Data System (ADS)

    Kymplova, Jaroslava; Navratil, Leos; Skopek, Jiri

    2001-10-01

    Keloid scars trouble the patients particularly for aesthetical reasons. They also frequency result in various functional disturbances, they are painful and the patient suffers for dysesthesia on touch. Low level laser is able to provide three principal effects: biostimulating, analgesic and antiinflammatory. Particularly thanks to the first two effects we are able, when adhering to the proper therapeutic procedure, to moderate or even remove the above mentioned problems. We complement the low level laser treatment by applications of ointments, cremes or silicone strips. Our communication is aimed at a case report concerning the treatment of keloid scars resulting from an injury by a jellyfish with the aim to familiarize the reader with wide therapeutic possibilities of non-invasive laser, even in indications which are not frequently encountered in central Europe.

  7. Settlement of Planulae of the Moon Jellyfish Aurelia aurita onto Hydrophilic Polycarbonate Plates Modified by Atmospheric Plasma Treatment

    PubMed Central

    Tomaru, Akiko; Sasaki, Ryota; Miyahara, Hidekazu; Okino, Akitoshi; Ogawa, Nobuhiro; Hamasaki, Koji

    2014-01-01

    It has been reported that planula larvae of some jellyfish prefer artificial substrates for settlement. This research focused on the relationship between the settlement of planulae and the wettability of artificial substrate surfaces. We used atmospheric plasmas to change the wettability of the surfaces of polycarbonate (PC) plates because plasma treatment has no chemical side effects. The treatment made the surfaces hydrophilic, as evidenced by the decrease of contact angle from 85° to 35°. X-ray photoelectron spectroscopy revealed that the change of wettability of the PC plates could be attributed to N2, which was probably ionized in the air above the plates. Scanning electron microscopy revealed no difference in the surface morphology of the plates before and after plasma treatment. Results of bioassays using treated PC plates showed that planulae tended to preferentially settle on hydrophobic surfaces. PMID:24465603

  8. 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

  9. Surviving but not thriving: inconsistent responses of zooxanthellate jellyfish polyps to ocean warming and future UV-B scenarios.

    PubMed

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

    2016-01-01

    Complex changes to UV radiation at the Earth's surface are occurring concurrently with ocean warming. Despite few empirical tests, jellyfish are hypothesised to be increasing in some parts of the world because they are robust to environmental stressors. Here we examine the effects of UV-B and ocean warming projections on zooxanthellate jellyfish polyps. We exposed Cassiopea sp. polyps to three levels of UV-B (future-low (1.43 Wm(2)), current (1.60 Wm(2)), future-high (1.77 Wm(2))) and two levels of temperature (current-day (25 °C) and future (28 °C)) over 6 weeks. The intensity of UV-B was varied throughout the day to mimic diel variation in UV-B irradiance. Polyp survival, asexual reproduction and YII were measured. In the current and future-high UV-B treatments, more polyps were produced in 25 °C than 28 °C. This pattern, however, was reversed under future-low UV-B conditions, where more polyps were produced at 28 °C. YII was highest under current summer conditions and future conditions of low UV-B and increased temperature. YII, however, was reduced under high UV-B conditions but was further reduced with warming. Our results suggest that although Cassiopea polyps may survive elevated UV-B and warming conditions, they are unlikely to thrive. If, however, UV-B radiation decreases then ocean warming may facilitate increases in Cassiopea populations. PMID:27374028

  10. Surviving but not thriving: inconsistent responses of zooxanthellate jellyfish polyps to ocean warming and future UV-B scenarios

    NASA Astrophysics Data System (ADS)

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

    2016-07-01

    Complex changes to UV radiation at the Earth’s surface are occurring concurrently with ocean warming. Despite few empirical tests, jellyfish are hypothesised to be increasing in some parts of the world because they are robust to environmental stressors. Here we examine the effects of UV-B and ocean warming projections on zooxanthellate jellyfish polyps. We exposed Cassiopea sp. polyps to three levels of UV-B (future-low (1.43 Wm2), current (1.60 Wm2), future-high (1.77 Wm2)) and two levels of temperature (current-day (25 °C) and future (28 °C)) over 6 weeks. The intensity of UV-B was varied throughout the day to mimic diel variation in UV-B irradiance. Polyp survival, asexual reproduction and YII were measured. In the current and future-high UV-B treatments, more polyps were produced in 25 °C than 28 °C. This pattern, however, was reversed under future-low UV-B conditions, where more polyps were produced at 28 °C. YII was highest under current summer conditions and future conditions of low UV-B and increased temperature. YII, however, was reduced under high UV-B conditions but was further reduced with warming. Our results suggest that although Cassiopea polyps may survive elevated UV-B and warming conditions, they are unlikely to thrive. If, however, UV-B radiation decreases then ocean warming may facilitate increases in Cassiopea populations.

  11. 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. PMID:24977703

  12. 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

  13. Surviving but not thriving: inconsistent responses of zooxanthellate jellyfish polyps to ocean warming and future UV-B scenarios

    PubMed Central

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

    2016-01-01

    Complex changes to UV radiation at the Earth’s surface are occurring concurrently with ocean warming. Despite few empirical tests, jellyfish are hypothesised to be increasing in some parts of the world because they are robust to environmental stressors. Here we examine the effects of UV-B and ocean warming projections on zooxanthellate jellyfish polyps. We exposed Cassiopea sp. polyps to three levels of UV-B (future-low (1.43 Wm2), current (1.60 Wm2), future-high (1.77 Wm2)) and two levels of temperature (current-day (25 °C) and future (28 °C)) over 6 weeks. The intensity of UV-B was varied throughout the day to mimic diel variation in UV-B irradiance. Polyp survival, asexual reproduction and YII were measured. In the current and future-high UV-B treatments, more polyps were produced in 25 °C than 28 °C. This pattern, however, was reversed under future-low UV-B conditions, where more polyps were produced at 28 °C. YII was highest under current summer conditions and future conditions of low UV-B and increased temperature. YII, however, was reduced under high UV-B conditions but was further reduced with warming. Our results suggest that although Cassiopea polyps may survive elevated UV-B and warming conditions, they are unlikely to thrive. If, however, UV-B radiation decreases then ocean warming may facilitate increases in Cassiopea populations. PMID:27374028

  14. Interannual variability in the Northern California Current food web structure: Changes in energy flow pathways and the role of forage fish, euphausiids, and jellyfish

    NASA Astrophysics Data System (ADS)

    Ruzicka, James J.; Brodeur, Richard D.; Emmett, Robert L.; Steele, John H.; Zamon, Jeannette E.; Morgan, Cheryl A.; Thomas, Andrew C.; Wainwright, Thomas C.

    2012-09-01

    The Northern California Current (NCC) is a seasonally productive and open ecosystem. It is home to both a diverse endemic community and to seasonally transient species. Productivity and food web structure vary seasonally, interannually, and decadally due to variability in coastal upwelling, climate-scale physical processes, and the migratory species entering the system. The composition of the pelagic community varies between years, including changes to mid-trophic level groups that represent alternate energy-transfer pathways between lower and upper trophic levels (forage fishes, euphausiids, jellyfish). Multiple data sets, including annual spring and summer mesoscale surveys of the zooplankton, pelagic fish, and seabird communities, were used to infer NCC trophic network arrangements and develop end-to-end models for each of the 2003-2007 upwelling seasons. Each model was used to quantify the interannual variability in energy-transfer efficiency from bottom to top trophic levels. When each model was driven under an identical nutrient input rate, substantial differences in the energy available to each functional group were evident. Scenario analyses were used to examine the roles of forage fishes, euphausiids, and jellyfish (small gelatinous zooplankton and large carnivorous jellyfish) as alternate energy transfer pathways. Euphausiids were the more important energy transfer pathway; a large proportion of the lower trophic production consumed was transferred to higher trophic levels. In contrast, jellyfish acted as a production loss pathway; little of the production consumed was passed upwards. Analysis of the range of ecosystem states observed interannually and understanding system sensitivity to variability among key trophic groups improves our ability to predict NCC ecosystem response to short- and long-term environmental change.

  15. Development of a rapid assay to detect the jellyfish Cyanea nozakii using a loop-mediated isothermal amplification method.

    PubMed

    Liu, Zhongyuan; Dong, Zhijun; Liu, Dongyan

    2016-07-01

    Blooms of the harmful jellyfish Cyanea nozakii, which are a severe nuisance to fisheries and tourisms, frequently occur in the northern East China Sea, Yellow Sea, and Bohai Sea. To provide early warning of this species, a simple and effective molecular method for identifying C. nozakii was developed using the loop-mediated isothermal amplification method (LAMP). The LAMP assay is highly specific and uses a set of four primers that target six different regions on the mitochondrial cytochrome c oxidase subunit I (COI) gene of C. nozakii. The amplification conditions, including the dNTP and betaine concentrations, the inner primer to outer primer concentration ratio, reaction time and temperature, were optimized. The LAMP assay amplified DNA extracted from tissue samples of C. nozakii but did not amplify DNA from other common scyphozoans and hydrozoans collected in the same region. In addition, the LAMP assay was more sensitive than conventional PCR. Therefore, the established LAMP assay is a sensitive, specific, fast, and easily performed method for detection of C. nozakii at different stages in their life cycle. PMID:25774948

  16. Preliminary results of the in vivo and in vitro characterization of a tentacle venom fraction from the jellyfish Aurelia aurita.

    PubMed

    Ponce, Dalia; López-Vera, Estuardo; Aguilar, Manuel B; Sánchez-Rodríguez, Judith

    2013-12-01

    The neurotoxic effects produced by a tentacle venom extract and a fraction were analyzed and correlated by in vivo and in vitro approaches. The tentacle venom extract exhibited a wide range of protein components (from 24 to >225 kDa) and produced tetanic reactions, flaccid paralysis, and death when injected into crabs. Two chromatography fractions also produced uncontrolled appendix movements and leg stretching. Further electrophysiological characterization demonstrated that one of these fractions potently inhibited ACh-elicited currents mediated by both vertebrate fetal and adult muscle nicotinic acetylcholine receptors (nAChR) subtypes. Receptor inhibition was concentration-dependent and completely reversible. The calculated IC(50) values were 1.77 μg/μL for fetal and 2.28 μg/μL for adult muscle nAChRs. The bioactive fraction was composed of a major protein component at ~90 kDa and lacked phospholipase A activity. This work represents the first insight into the interaction of jellyfish venom components and muscle nicotinic receptors. PMID:24322597

  17. Selectivity in phagocytosis and persistence of symbiotic algae in the scyphistoma stage of the jellyfish Cassiopeia xamachana.

    PubMed

    Colley, N J; Trench, R K

    1983-08-22

    We have investigated whether interactions between cell-surface macromolecules play a role in cellular recognition leading to specificity in the establishment of intracellular symbiosis between dinoflagellates and the polyp (scyphistoma) stage of the jellyfish Cassiopeia xamachana. All strains of the symbiotic dinoflagellate Symbiodinium microadriaticum were phagocytosed by the endodermal cells of the scyphistomae when presented to them as cells freshly isolated from their respective hosts. The rates of phagocytosis of such cells were high, and were directly correlated with the presence of a membrane, thought to be the host cell vacuolar membrane that surrounds the freshly isolated algae. Cultured algae lack this membrane. All cultured algae, even those that proliferate in host tissues, were phagocytosed at very low or undetectable rates. Freshly isolated algae treated with reagents that removed the host membrane were phagocytosed at low rates. The endodermal cells of the scyphistomae of the non-symbiotic medusa Aurelia aurita also phagocytosed freshly isolated algae, but did not phagocytose cultured algae. Phagocytosis of algae and carmine particles was found to be a competitive process in scyphistomae of C. xamachana. No correlation was observed between the surface electrical charge on algae and their phagocytosis by host endodermal cells. Neither was there any correlation between phagocytosis and persistence. We conclude that the specificity in symbioses between marine invertebrates and dinoflagellates appears to be regulated by processes that occur after potential algal symbionts are phagocytosed. PMID:22470960

  18. Preliminary Results of the in Vivo and in Vitro Characterization of a Tentacle Venom Fraction from the Jellyfish Aurelia aurita

    PubMed Central

    Ponce, Dalia; López-Vera, Estuardo; Aguilar, Manuel B.; Sánchez-Rodríguez, Judith

    2013-01-01

    The neurotoxic effects produced by a tentacle venom extract and a fraction were analyzed and correlated by in vivo and in vitro approaches. The tentacle venom extract exhibited a wide range of protein components (from 24 to >225 kDa) and produced tetanic reactions, flaccid paralysis, and death when injected into crabs. Two chromatography fractions also produced uncontrolled appendix movements and leg stretching. Further electrophysiological characterization demonstrated that one of these fractions potently inhibited ACh-elicited currents mediated by both vertebrate fetal and adult muscle nicotinic acetylcholine receptors (nAChR) subtypes. Receptor inhibition was concentration-dependent and completely reversible. The calculated IC50 values were 1.77 μg/μL for fetal and 2.28 μg/μL for adult muscle nAChRs. The bioactive fraction was composed of a major protein component at ~90 kDa and lacked phospholipase A activity. This work represents the first insight into the interaction of jellyfish venom components and muscle nicotinic receptors. PMID:24322597

  19. The Acaricidal Activity of Venom from the Jellyfish Nemopilema nomurai against the Carmine Spider Mite Tetranychus cinnabarinus

    PubMed Central

    Yu, Huahua; Yue, Yang; Dong, Xiangli; Li, Rongfeng; Li, Pengcheng

    2016-01-01

    The carmine spider mite Tetranychus cinnabarinus (T. cinnabarinus) is a common polyphagous pest that attacks crops, vegetables, flowers, and so on. It is necessary to find lead compounds for developing novel, powerful, and environmentally-friendly acaricides as an alternative approach to controlling the carmine spider mite because of the serious resistance and residual agrochemicals in the environment. In addition, the study on the acaricidal activities of marine bioactive substances is comparatively deficient. In the present study, the acaricidal activity of venom (NnFV) from the jellyfish Nemopilema nomurai against the carmine spider mite T. cinnabarinus was determined for the first time. The venom had contact toxicity, and the 24-h LC50-value was 29.1 μg/mL. The mite body wall was affected by the venom, with the mite body having no luster and being seriously shrunken after 24 h. T. cinnabarinus was a potential target pest of NnFV, which had potential as a type of natural bioacaricide. The repellent activity and systemic toxicity of the venom against T. cinnabarinus were also studied. However, NnFV had no repellent activity and systemic toxicity against T. cinnabarinus. PMID:27294957

  20. Density and sound speed of two gelatinous zooplankton: ctenophore (Mnemiopsis leidyi) and lion's mane jellyfish (Cyanea capillata).

    PubMed

    Warren, Joseph D; Smith, Joy N

    2007-07-01

    The density and sound speed of two coastal, gelatinous zooplankton, Mnemiopsis leidyi (a ctenophore) and Cyanea capillata (lion's mane jellyfish), were measured. These parameters are important inputs to acoustic scattering models. Two different methods were used to measure the density of individual animals: one used a balance and graduated cylinder to determine the mass and displacement volume of the animal, the other varied the density of the solution the animal was immersed in. When the same animal was measured using both methods, density values were within 1% of each other. A travel-time difference method was used to measure the sound speed within the animals. The densities of both zooplankton slightly decreased as the animals increased in length, mass, and volume. The ratio of animal density and sound speed to the surrounding seawater (g and h, respectively) are reported for both animals. For Mnemiopsis leidyi ranging in length from 1 to 5 cm, the mean value (+/-standard deviation) of g and h were 1.009 (+/-0.004) and 1.007 (+/-0.001). For Cyanea capillata ranging in bell diameter from 2 to 11 cm, the mean value (+/-standard deviation) of g and single value of h were 1.009 (+/-0.004) and 1.0004. PMID:17614513

  1. The Acaricidal Activity of Venom from the Jellyfish Nemopilema nomurai against the Carmine Spider Mite Tetranychus cinnabarinus.

    PubMed

    Yu, Huahua; Yue, Yang; Dong, Xiangli; Li, Rongfeng; Li, Pengcheng

    2016-01-01

    The carmine spider mite Tetranychus cinnabarinus (T. cinnabarinus) is a common polyphagous pest that attacks crops, vegetables, flowers, and so on. It is necessary to find lead compounds for developing novel, powerful, and environmentally-friendly acaricides as an alternative approach to controlling the carmine spider mite because of the serious resistance and residual agrochemicals in the environment. In addition, the study on the acaricidal activities of marine bioactive substances is comparatively deficient. In the present study, the acaricidal activity of venom (NnFV) from the jellyfish Nemopilema nomurai against the carmine spider mite T. cinnabarinus was determined for the first time. The venom had contact toxicity, and the 24-h LC50-value was 29.1 μg/mL. The mite body wall was affected by the venom, with the mite body having no luster and being seriously shrunken after 24 h. T. cinnabarinus was a potential target pest of NnFV, which had potential as a type of natural bioacaricide. The repellent activity and systemic toxicity of the venom against T. cinnabarinus were also studied. However, NnFV had no repellent activity and systemic toxicity against T. cinnabarinus. PMID:27294957

  2. Box jellyfish (Carybdea alata) in Waikiki: their influx cycle plus the analgesic effect of hot and cold packs on their stings to swimmers at the beach: a randomized, placebo-controlled, clinical trial.

    PubMed

    Thomas, C S; Scott, S A; Galanis, D J; Goto, R S

    2001-04-01

    The study measured the analgesic effect of hot and cold packs on box jellyfish (Carybdea alata) stings to Waikiki swimmers at the beach. Analysis of data showed a minimal trend toward pain relief 10 minutes after the application of hot packs, particularly when the initial pain was mild to moderate. Cold packs showed no clinically significant relief of pain, compared to the control. Data tracking shows that most box jellyfish appear in Waikiki waters on the 9th or 10th day after the full moon. PMID:11383098

  3. Spatiotemporal variation in community structure of marine benthic ciliates in the Yellow Sea during and after macroalgal and giant jellyfish blooms

    NASA Astrophysics Data System (ADS)

    Zhou, Bailing; Xu, Kuidong

    2016-01-01

    The annual bloom of the green macroalgal Ulva prolifera from May through July since 2008 and another of giant jellyfish Nemopilema nomurai from June through September have been frequent events in the Yellow Sea. However, the patterns of benthic ciliate communities during and after the blooms are still not known. In combination with analyses of benthic environmental factors, we investigated the distribution and community composition of benthic ciliates in the Yellow Sea in July and November 2011. In July, ciliates had high standing crops and diversity in the northern Yellow Sea, and in the inshore area off the southern Shandong Peninsula, where large numbers of green macroalgae accumulated. In November, the abundance, biomass and diversity of ciliates were high in the sea areas off the Shandong Peninsula and Changjiang estuary, where a large quantity of jellyfish occurred in August. Neither the abundance nor the biomass had significant diff erence between seasons, or between diff erent compartments of the Yellow Sea. The species number, and both Margalef and Shannon-Wiener indices of ciliates were all significantly higher in November than in July. In both seasons, prostomateans and karyorelicteans consistently constituted the first and second most important ciliate groups in biomass; and carnivorous ciliates constituted the primary feeding type in terms of biomass as well as species richness, followed by bacterivores, algivores and omnivores. Compared with that in June 2007 when no macroalgae occurred, the percentage of small-sized bacterivores (e.g. Metacystis spp., Euplotes spp. and scuticociliates) increased in July 2011. The proportion of carnivorous ciliates increased in November, and this increased dominance of carnivorous ciliates may be a response to the increase in predominance of heterotrophic nanoflagellates, which might in turn be ascribed to an eff ect of green macroalgal and giant jellyfish blooms in the Yellow Sea.

  4. Spatiotemporal variation in community structure of marine benthic ciliates in the Yellow Sea during and after macroalgal and giant jellyfish blooms

    NASA Astrophysics Data System (ADS)

    Zhou, Bailing; Xu, Kuidong

    2016-07-01

    The annual bloom of the green macroalgal Ulva prolifera from May through July since 2008 and another of giant jellyfish Nemopilema nomurai from June through September have been frequent events in the Yellow Sea. However, the patterns of benthic ciliate communities during and after the blooms are still not known. In combination with analyses of benthic environmental factors, we investigated the distribution and community composition of benthic ciliates in the Yellow Sea in July and November 2011. In July, ciliates had high standing crops and diversity in the northern Yellow Sea, and in the inshore area off the southern Shandong Peninsula, where large numbers of green macroalgae accumulated. In November, the abundance, biomass and diversity of ciliates were high in the sea areas off the Shandong Peninsula and Changjiang estuary, where a large quantity of jellyfish occurred in August. Neither the abundance nor the biomass had significant difference between seasons, or between different compartments of the Yellow Sea. The species number, and both Margalef and Shannon-Wiener indices of ciliates were all significantly higher in November than in July. In both seasons, prostomateans and karyorelicteans consistently constituted the first and second most important ciliate groups in biomass; and carnivorous ciliates constituted the primary feeding type in terms of biomass as well as species richness, followed by bacterivores, algivores and omnivores. Compared with that in June 2007 when no macroalgae occurred, the percentage of small-sized bacterivores (e.g. Metacystis spp., Euplotes spp. and scuticociliates) increased in July 2011. The proportion of carnivorous ciliates increased in November, and this increased dominance of carnivorous ciliates may be a response to the increase in predominance of heterotrophic nanoflagellates, which might in turn be ascribed to an effect of green macroalgal and giant jellyfish blooms in the Yellow Sea.

  5. The "eyes absent" (eya) gene in the eye-bearing hydrozoan jellyfish Cladonema radiatum: conservation of the retinal determination network.

    PubMed

    Graziussi, Daria Federica; Suga, Hiroshi; Schmid, Volker; Gehring, Walter Jakob

    2012-06-01

    Eyes absent (Eya) is a member of the Retinal Determination Gene Network (RDGN), a set of genes responsible for eye specification in Drosophila. Eya is a dual function protein, working as a transcription factor in the nucleus and as a tyrosine phosphatase in the cytoplasm. It had been shown that Pax and Six family genes, main components of the RDGN, are present in the hydrozoan Cladonema radiatum and that they are expressed in the eye. However, nothing had been known about the Eya family in hydrozoan jellyfish. Here we report the presence of an Eya homologue (CrEya) in Cladonema. Real-time PCR analysis and in situ hybridization showed that CrEya is expressed in the eye. Furthermore, the comprehensive survey of eukaryote genomes revealed that the acquisition of the N-terminal transactivation domain, including the EYA Domain 2 and its adjacent sequence shared by all eumetazoans, happened early in evolution, before the separation of Cnidaria and Bilateria. Our results uncover the evolution of the two domains and show a conservation of the expression pattern of the Eya gene between Cnidaria and Bilateria, which, together with previous data, supports the hypothesis of the monophyletic origin of metazoans eyes. We additionally show that CrEya is also expressed in the oocytes, where two other members of the RDGN, CrPaxB, and Six4/5-Cr, are known to be expressed. These data suggest that several members of the RDGN have begun to be localized also into the different context of egg development early in the course of metazoan evolution. PMID:22821862

  6. 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.

  7. Spatial distribution of the upside-down jellyfish Cassiopea sp. within fringing coral reef environments of the Northern Red Sea: implications for its life cycle

    NASA Astrophysics Data System (ADS)

    Niggl, Wolfgang; Wild, Christian

    2010-12-01

    The zooxanthellate mangrove jellyfish Cassiopea sp. represents a prominent invasive species and a potential bioindicator for nutrient monitoring in coral reefs. However, information about its spatial distribution in combination with abundance, habitat specificity and life cycle elements is barely available. This study, therefore, presents the results of field surveys conducted within four different benthic habitat types (coral reef, seagrass meadow, reef-sand transition and sand flat) in the Northern Red Sea. Cassiopea sp. exhibited a highly patchy distribution within the entire study area with mean abundance of 1.6 ± 0.3 animals m-2 and benthic coverage of 3.2%. Within coral reef habitats, maximum abundance of up to 31 animals m-2 and benthic coverage of up to 20% were detected. Additionally, this study revealed that 65% of all observed Cassiopea specimens were associated with the commensalistic crustacean mysid Idiomysis tsurnamali. Cassiopea abundance and size as well as association patterns with mysids differed between most of the surveyed habitats. In summary, the findings of the present study (1) characterize Cassiopea as one of the key organisms in investigated benthic habitats, (2) indicate active habitat selection by the jellyfish and (3) may hint to an unexplored life cycle of Cassiopea with central role of seagrass meadows providing cues for larval settlement and metamorphosis in the absence of mangroves.

  8. Apoptosis-like cell death induced by nematocyst venom from Chrysaora helvola Brandt jellyfish and an in vitro evaluation of commonly used antidotes.

    PubMed

    Qu, Xiaosheng; Xia, Xianghua; Lai, Zefeng; Zhong, Taozheng; Li, Gang; Fan, Lanlan; Shu, Wei

    2016-02-01

    The present work investigated the in vitro cytotoxicity of nematocyst venom (NV) from Chrysaora helvola Brandt (C. helvola) jellyfish against human MCF-7 and CNE-2 tumor cell lines. Potent cytotoxicity was quantified using the MTT assay (LC50=12.07±3.13 and 1.6±0.22μg/mL (n=4), respectively). Apoptosis-like cell death was further confirmed using the LDH release assay and Annexin V/PI double staining-based flow cytometry analysis. However, only activation of caspase-4 was observed. It is possible that some caspase-independent pathways were activated by the NV treatment. Since no reference or antivenom is available, the effects of several commonly used antidotes on the cytotoxicity of NV were examined on more sensitive CNE-2 cells to determine the appropriate emergency measures for envenomation by C. helvola. The phospholipase A2 (PLA2) inhibitor para-bromophenacyl bromide (pBPB) showed no protective effect, while Mg(2+) potentiated cytotoxicity. Voltage-gated L-type Ca(2+) channel blockers (verapamil, nifedipine and felodipine) and Na-Ca(2+) exchanger inhibitor KB-R7943 also showed no effect. Assays using Ca(2+)-free culture media or the intracellular Ca(2+) chelator BAPTA also could not inhibit the cytotoxicity. Taken together, these results suggest that PLA2 and Ca(2+) are not directly involved in the cytotoxicity of NV from C. helvola. Our work also suggests caution regarding the choice for first aid for envenomation by C. helvola jellyfish. PMID:26538054

  9. A rapid and repeatable method for venom extraction from cubozoan nematocysts.

    PubMed

    Carrette, T; Seymour, J

    2004-08-01

    Various comparative studies into the biological activity and relative toxicity of cubozoan venoms have been investigated, in particular the venom from the potentially lethal cubozoan Chironex fleckeri. Efficient and reliable extraction of venom from nematocysts is essential before any research into venom toxicity can be conducted and previous cited methods of extraction have varied greatly, each with their own associated problems. A new standardised technique for the recovery of venom from nematocysts of cubozoans is investigated to decrease the variation displayed between authors due to differing extraction techniques. The use of a mini bead mill beater, as investigated in this trial, allows for the rapid extraction of venom from nematocysts and is devoid of the previously isolated problems experienced with other methods of venom isolation, such as excessive heat build up. PMID:15246760

  10. Jellyfish Lake, Palau

    NASA Astrophysics Data System (ADS)

    Burnett, William C.; Landing, William M.; Lyons, W. Berry; Orem, William

    Elemental cycling in suboxic to anoxic marine environments has received considerable attention in the past few years. The recent expeditions of the RIV Knorr to the Black Sea, for example, illustrate the interest in deciphering the geochemical processes active in such environments “Murray, 1988”.This interest has been stimulated by the recognition that the type of elemental cycling that occurs in restrictive basins such as the Black Sea also occurs in many other environments. Examples include hydrothermal systems, estuarine and marine sediments, and other water columns with restrictive circulation. In addition, evidence that widespread anoxia has occurred in oceans of the geologic past “Fischer and Arthur, 1977; Jenkyns, 1980” requires us to obtain a better understanding of geochemical processes under such conditions. We report here on preliminary geochemical measurements made in a stratified marine lake—an unusual, yet useful environment as an analog of an anoxic ocean.

  11. Jellyfish Stings, First Aid

    MedlinePlus

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  12. The use of ephyrae of a scyphozoan jellyfish, Aurelia aurita, in the aquatic toxicological assessment of Macondo oils from the Deepwater Horizon incident.

    PubMed

    Echols, B S; Smith, A J; Gardinali, P R; Rand, G M

    2016-02-01

    Ephyrae of the scyphozoan jellyfish, Aurelia aurita, were evaluated in 96-hr acute toxicity tests for lethal response to Macondo crude oils from the Deepwater Horizon (DWH) incident in the Gulf of Mexico (GOM), Corexit 9500, and oil-dispersant mixtures. Water accommodated fractions (WAFs) of weathered and unweathered Macondo crude oils were not acutely toxic to ephyrae (LC50s > 100% WAF). The total PAHs (TPAHs), measured as the sum of 46 PAHs, averaged 21.1and 152 µg TPAH/L for WAFs of weathered and unweathered oil, respectively. Mortality was significantly (p = <0.0001) higher in the three highest exposure concentrations (184-736 µg TPAH/L) of chemically dispersed WAFs (CEWAF) compared to controls. Dispersant only tests resulted in a mean LC50 of 32.3 µL/L, which is in the range of previously published LC50s for marine zooplankton. Changes in appearance and muscle contractions were observed in organisms exposed to CEWAF dilutions of 12.5 and 25%, as early as 24 h post-exposure. Based on the results of these tests, crude oil alone did not cause significant acute toxicity; however, the presence of chemical dispersant resulted in substantial mortality and physical and behavioral abnormalities either due to an increase in hydrocarbons or droplet exposure. PMID:26547023

  13. In vitro angiotensin I converting enzyme inhibition by a peptide isolated from Chiropsalmus quadrigatus Haeckel (box jellyfish) venom hydrolysate.

    PubMed

    So, Pamela Berilyn T; Rubio, Peter; Lirio, Stephen; Macabeo, Allan Patrick; Huang, Hsi-Ya; Corpuz, Mary Jho-Anne T; Villaflores, Oliver B

    2016-09-01

    The anti-angiotensin I converting enzyme activity of box jellyfish, Chiropsalmus quadrigatus Haeckel venom hydrolysate was studied. The venom extract was obtained by centrifugation and ultrasonication. Protein concentration of 12.99 μg/mL was determined using Bradford assay. The pepsin and papain hydrolysate was tested for its toxicity by Limit test following the OECD Guideline 425 using 5 female Sprague-Dawley rats. Results showed that the hydrolysate is nontoxic with an LD50 above 2000 mg/kg. In vitro angiotensin I converting enzyme (ACE) inhibitory activity was determined using ACE kit-WST. Isolation of ACE inhibitory peptides using column chromatography with SP-Sephadex G-25 yielded 8 pooled fractions with fraction 3 (86.5%) exhibiting the highest activity. This was followed by reverse phase - high performance liquid chromatography (RP-HPLC) with an octadecyl silica column (Inertsil ODS-3) using methanol:water 15:85 at a flow rate of 1.0 mL/min. Among the 13 fractions separated with the RP-HPLC, fraction 3.5 exhibited the highest ACE inhibitory activity (84.1%). The peptide sequence ACPGPNPGRP (IC50 2.03 μM) from fraction 3.5 was identified using Matrix-assisted laser desorption/ionization with time-of-flight tandem mass spectroscopy analysis (MALDI-TOF/MS). PMID:27163886

  14. Aurelia labiata jellyfish in Roscoe Bay on the West Coast of Canada: Seasonal changes in adult bell diameter and mingling of juvenile and adult populations

    NASA Astrophysics Data System (ADS)

    Albert, David J.; Walsh, Michael L.

    2014-01-01

    The bell diameter of adult Aurelia labiata in Roscoe Bay increased from spring (April) to early summer (May/June) and decreased over the rest of the year (2009/2010). The increase in bell diameter in the spring would have been supported by the increase in zooplankton that occurs in the northeast Pacific at this time. Over the summer, bell diameter may have decreased because the food available/medusa would have been decreased by the arrival of a large number of juveniles and may have decreased further over the fall and winter when zooplankton levels are known to be low. Adults and juveniles were intermingled during 2010, 2011, and 2012. Correlations between the number of adults and number of juveniles obtained in individual net lifts across the entire bay and in different parts of the bay were all positive and most were statistically significant. In 2012, salinity in the entire water column of the west side of the bay dropped below 20 ppt in July and most medusae migrated to higher salinity in the east side of the bay, a distance of about 0.5 km. The mingling of adults and juveniles supports other evidence that adult Aurelia sp. medusae do not prey upon juveniles. The ability to withstand months with insufficient food and to inhibit preying on juveniles would contribute greatly to the survival of Aurelia sp. jellyfish.

  15. Mitrocomin from the jellyfish Mitrocoma cellularia with deleted C-terminal tyrosine reveals a higher bioluminescence activity compared to wild type photoprotein.

    PubMed

    Burakova, Ludmila P; Natashin, Pavel V; Markova, Svetlana V; Eremeeva, Elena V; Malikova, Natalia P; Cheng, Chongyun; Liu, Zhi-Jie; Vysotski, Eugene S

    2016-09-01

    The full-length cDNA genes encoding five new isoforms of Ca(2+)-regulated photoprotein mitrocomin from a small tissue sample of the outer bell margin containing photocytes of only one specimen of the luminous jellyfish Mitrocoma cellularia were cloned, sequenced, and characterized after their expression in Escherichia coli and subsequent purification. The analysis of cDNA nucleotide sequences encoding mitrocomin isoforms allowed suggestion that two isoforms might be the products of two allelic genes differing in one amino acid residue (64R/Q) whereas other isotypes appear as a result of transcriptional mutations. In addition, the crystal structure of mitrocomin was determined at 1.30Å resolution which expectedly revealed a high similarity with the structures of other hydromedusan photoproteins. Although mitrocomin isoforms reveal a high degree of identity of amino acid sequences, they vary in specific bioluminescence activities. At that, all isotypes displayed the identical bioluminescence spectra (473-474nm with no shoulder at 400nm). Fluorescence spectra of Ca(2+)-discharged mitrocomins were almost identical to their light emission spectra similar to the case of Ca(2+)-discharged aequorin, but different from Ca(2+)-discharged obelins and clytin which fluorescence is red-shifted by 25-30nm from bioluminescence spectra. The main distinction of mitrocomin from other hydromedusan photoproteins is an additional Tyr at the C-terminus. Using site-directed mutagenesis, we showed that this Tyr is not important for bioluminescence because its deletion even increases specific activity and efficiency of apo-mitrocomin conversion into active photoprotein, in contrast to C-terminal Pro of other photoproteins. Since genes in a population generally exist as different isoforms, it makes us anticipate the cloning of even more isoforms of mitrocomin and other hydromedusan photoproteins with different bioluminescence properties. PMID:27395792

  16. Use of an Inverse Method for Time Series to Estimate the Dynamics of and Management Strategies for the Box Jellyfish Carybdea marsupialis

    PubMed Central

    Bordehore, Cesar; Fuentes, Verónica L.; Segarra, Jose G.; Acevedo, Melisa; Canepa, Antonio; Raventós, Josep

    2015-01-01

    Frequently, population ecology of marine organisms uses a descriptive approach in which their sizes and densities are plotted over time. This approach has limited usefulness for design strategies in management or modelling different scenarios. Population projection matrix models are among the most widely used tools in ecology. Unfortunately, for the majority of pelagic marine organisms, it is difficult to mark individuals and follow them over time to determine their vital rates and built a population projection matrix model. Nevertheless, it is possible to get time-series data to calculate size structure and densities of each size, in order to determine the matrix parameters. This approach is known as a “demographic inverse problem” and it is based on quadratic programming methods, but it has rarely been used on aquatic organisms. We used unpublished field data of a population of cubomedusae Carybdea marsupialis to construct a population projection matrix model and compare two different management strategies to lower population to values before year 2008 when there was no significant interaction with bathers. Those strategies were by direct removal of medusae and by reducing prey. Our results showed that removal of jellyfish from all size classes was more effective than removing only juveniles or adults. When reducing prey, the highest efficiency to lower the C. marsupialis population occurred when prey depletion affected prey of all medusae sizes. Our model fit well with the field data and may serve to design an efficient management strategy or build hypothetical scenarios such as removal of individuals or reducing prey. TThis This sdfsdshis method is applicable to other marine or terrestrial species, for which density and population structure over time are available. PMID:26376483

  17. Classification of choroiditis based on inflammatory lesion process rather than fundus appearance: enhanced comprehension through the ICGA concepts of the iceberg and jellyfish effects.

    PubMed

    Herbort, C P; Papadia, M; Mantovani, A

    2012-04-01

    Choroidal inflammatory diseases have been classically grouped under the term of white dot syndromes (WDS), a term only based on the appearance (white-yellow dots) of inflammatory fundus lesions. This purely descriptive and vague terminology, regrouping a pot-pourri of posterior inflammatory conditions, probably came into use because the precise exploration of the choroid was not possible, and also because many of the diseases were rare and not well understood. Since the availability of indocyanine green angiography (ICGA) that allows one to explore the choroidal compartment, it became possible to understand the lesion mechanism of choroiditides and to classify this group of diseases according to their pathophysiological behaviour. It was our aim to show here that the term WDS is applied to and encompasses inflammatory conditions that are characterized by completely different lesion mechanisms and should therefore be classified separately from each other. ICGA made it possible to differentiate two types of choroiditides, including on the one hand inflammatory diseases of the choroidal stroma and on the other hand inflammatory diseases of the choriocapillaris. Unfortunately, twenty years after its advent, ICGA is still not used routinely in uveitis centres and the traditional inappropriate but overall useless term of WDS is still used, maintaining the confusion about these diseases. The aim of this work was (i) to illustrate that meaningful exploration of choroidal inflammation, mostly occult and inaccessible to usual investigations, has to be performed using ICGA, (ii) to insist on the crucial importance of ICGA in the management of choroiditis and (iii) to enhance the comprehension of the ICGA-based classification of choroiditis, by using the demonstrative and striking analogue concepts of iceberg and jellyfish effects. PMID:22495994

  18. Use of an Inverse Method for Time Series to Estimate the Dynamics of and Management Strategies for the Box Jellyfish Carybdea marsupialis.

    PubMed

    Bordehore, Cesar; Fuentes, Verónica L; Segarra, Jose G; Acevedo, Melisa; Canepa, Antonio; Raventós, Josep

    2015-01-01

    Frequently, population ecology of marine organisms uses a descriptive approach in which their sizes and densities are plotted over time. This approach has limited usefulness for design strategies in management or modelling different scenarios. Population projection matrix models are among the most widely used tools in ecology. Unfortunately, for the majority of pelagic marine organisms, it is difficult to mark individuals and follow them over time to determine their vital rates and built a population projection matrix model. Nevertheless, it is possible to get time-series data to calculate size structure and densities of each size, in order to determine the matrix parameters. This approach is known as a "demographic inverse problem" and it is based on quadratic programming methods, but it has rarely been used on aquatic organisms. We used unpublished field data of a population of cubomedusae Carybdea marsupialis to construct a population projection matrix model and compare two different management strategies to lower population to values before year 2008 when there was no significant interaction with bathers. Those strategies were by direct removal of medusae and by reducing prey. Our results showed that removal of jellyfish from all size classes was more effective than removing only juveniles or adults. When reducing prey, the highest efficiency to lower the C. marsupialis population occurred when prey depletion affected prey of all medusae sizes. Our model fit well with the field data and may serve to design an efficient management strategy or build hypothetical scenarios such as removal of individuals or reducing prey. TThis This sdfsdshis method is applicable to other marine or terrestrial species, for which density and population structure over time are available. PMID:26376483

  19. Evolution of paired domains: Isolation and sequencing of jellyfish and hydra Pax genes related to Pax-5 and Pax-6

    PubMed Central

    Sun, Hongmin; Rodin, Andrei; Zhou, Yihong; Dickinson, Douglas P.; Harper, Donald E.; Hewett-Emmett, David; Li, Wen-Hsiung

    1997-01-01

    Pax proteins are a family of transcription factors with a highly conserved paired domain; many members also contain a paired-type homeodomain and/or an octapeptide. Nine mammalian Pax genes are known and classified into four subgroups: Pax-1/9, Pax-2/5/8, Pax-3/7, and Pax-4/6. Most of these genes are involved in nervous system development. In particular, Pax-6 is a key regulator that controls eye development in vertebrates and Drosophila. Although the Pax-4/6 subgroup seems to be more closely related to Pax-2/5/8 than to Pax-3/7 or Pax-1/9, its evolutionary origin is unknown. We therefore searched for a Pax-6 homolog and related genes in Cnidaria, which is the lowest phylum of animals that possess a nervous system and eyes. A sea nettle (a jellyfish) genomic library was constructed and two pax genes (Pax-A and -B) were isolated and partially sequenced. Surprisingly, unlike most known Pax genes, the paired box in these two genes contains no intron. In addition, the complete cDNA sequences of hydra Pax-A and -B were obtained. Hydra Pax-B contains both the homeodomain and the octapeptide, whereas hydra Pax-A contains neither. DNA binding assays showed that sea nettle Pax-A and -B and hydra Pax-A paired domains bound to a Pax-5/6 site and a Pax-5 site, although hydra Pax-B paired domain bound neither. An alignment of all available paired domain sequences revealed two highly conserved regions, which cover the DNA binding contact positions. Phylogenetic analysis showed that Pax-A and especially Pax-B were more closely related to Pax-2/5/8 and Pax-4/6 than to Pax-1/9 or Pax-3/7 and that the Pax genes can be classified into two supergroups: Pax-A/Pax-B/Pax-2/5/8/4/6 and Pax-1/9/3/7. From this analysis and the gene structure, we propose that modern Pax-4/6 and Pax-2/5/8 genes evolved from an ancestral gene similar to cnidarian Pax-B, having both the homeodomain and the octapeptide. PMID:9144207

  20. Devin, Alligators, Jellyfish, and Me.

    ERIC Educational Resources Information Center

    Tsuchiyama, Elaine

    1997-01-01

    Describes how a first-grade teacher used the "hypothesis-test" approach with Devin, a first grader who struggled as a reader and writer. Points out that, when she started working with Devin, she wanted to understand his difficulties, but by the end, she realized that it was her curriculum, not his difficulties, that needed to be in the foreground.…

  1. For the Classroom: "Plastic" Jellyfish.

    ERIC Educational Resources Information Center

    Current: The Journal of Marine Education, 1989

    1989-01-01

    Describes an activity in which students monitor the plastic waste production in their households, research its effects on freshwater and marine life, and propose ways to lessen the problem. Provides objectives, background information, materials, procedures, extension activities, and an evaluation for students. (Author/RT)

  2. Propulsion in Cubomedusae: Mechanisms and Utility

    PubMed Central

    Colin, Sean P.; Costello, John H.; Katija, Kakani; Seymour, Jamie; Kiefer, Kristen

    2013-01-01

    Evolutionary constraints which limit the forces produced during bell contractions of medusae affect the overall medusan morphospace such that jet propulsion is limited to only small medusae. Cubomedusae, which often possess large prolate bells and are thought to swim via jet propulsion, appear to violate the theoretical constraints which determine the medusan morphospace. To examine propulsion by cubomedusae, we quantified size related changes in wake dynamics, bell shape, swimming and turning kinematics of two species of cubomedusae, Chironex fleckeri and Chiropsella bronzie. During growth, these cubomedusae transitioned from using jet propulsion at smaller sizes to a rowing-jetting hybrid mode of propulsion at larger sizes. Simple modifications in the flexibility and kinematics of their velarium appeared to be sufficient to alter their propulsive mode. Turning occurs during both bell contraction and expansion and is achieved by generating asymmetric vortex structures during both stages of the swimming cycle. Swimming characteristics were considered in conjunction with the unique foraging strategy used by cubomedusae. PMID:23437122

  3. Propulsion in cubomedusae: mechanisms and utility.

    PubMed

    Colin, Sean P; Costello, John H; Katija, Kakani; Seymour, Jamie; Kiefer, Kristen

    2013-01-01

    Evolutionary constraints which limit the forces produced during bell contractions of medusae affect the overall medusan morphospace such that jet propulsion is limited to only small medusae. Cubomedusae, which often possess large prolate bells and are thought to swim via jet propulsion, appear to violate the theoretical constraints which determine the medusan morphospace. To examine propulsion by cubomedusae, we quantified size related changes in wake dynamics, bell shape, swimming and turning kinematics of two species of cubomedusae, Chironex fleckeri and Chiropsella bronzie. During growth, these cubomedusae transitioned from using jet propulsion at smaller sizes to a rowing-jetting hybrid mode of propulsion at larger sizes. Simple modifications in the flexibility and kinematics of their velarium appeared to be sufficient to alter their propulsive mode. Turning occurs during both bell contraction and expansion and is achieved by generating asymmetric vortex structures during both stages of the swimming cycle. Swimming characteristics were considered in conjunction with the unique foraging strategy used by cubomedusae. PMID:23437122

  4. Heat Beats Cold for Treating Jellyfish Stings

    MedlinePlus

    ... Recreational) Recent Health News Related MedlinePlus Health Topics Water Safety (Recreational) About MedlinePlus Site Map FAQs Contact Us Get email updates Subscribe to RSS Follow us Disclaimers Copyright Privacy Accessibility Quality Guidelines Viewers & Players MedlinePlus Connect for EHRs For ...

  5. Systematics of stalked jellyfishes (Cnidaria: Staurozoa)

    PubMed Central

    Hirano, Yayoi M.; Mills, Claudia E.; Falconer, Audrey; Fenwick, David

    2016-01-01

    Staurozoan classification is highly subjective, based on phylogeny-free inferences, and suborders, families, and genera are commonly defined by homoplasies. Additionally, many characters used in the taxonomy of the group have ontogenetic and intraspecific variation, and demand new and consistent assessments to establish their correct homologies. Consequently, Staurozoa is in need of a thorough systematic revision. The aim of this study is to propose a comprehensive phylogenetic hypothesis for Staurozoa, providing the first phylogenetic classification for the group. According to our working hypothesis based on a combined set of molecular data (mitochondrial markers COI and 16S, and nuclear markers ITS, 18S, and 28S), the traditional suborders Cleistocarpida (animals with claustrum) and Eleutherocarpida (animals without claustrum) are not monophyletic. Instead, our results show that staurozoans are divided into two groups, herein named Amyostaurida and Myostaurida, which can be distinguished by the absence/presence of interradial longitudinal muscles in the peduncle, respectively. We propose a taxonomic revision at the family and genus levels that preserves the monophyly of taxa. We provide a key for staurozoan genera and discuss the evolution of the main characters used in staurozoan taxonomy. PMID:27168970

  6. Systematics of stalked jellyfishes (Cnidaria: Staurozoa).

    PubMed

    Miranda, Lucília S; Hirano, Yayoi M; Mills, Claudia E; Falconer, Audrey; Fenwick, David; Marques, Antonio C; Collins, Allen G

    2016-01-01

    Staurozoan classification is highly subjective, based on phylogeny-free inferences, and suborders, families, and genera are commonly defined by homoplasies. Additionally, many characters used in the taxonomy of the group have ontogenetic and intraspecific variation, and demand new and consistent assessments to establish their correct homologies. Consequently, Staurozoa is in need of a thorough systematic revision. The aim of this study is to propose a comprehensive phylogenetic hypothesis for Staurozoa, providing the first phylogenetic classification for the group. According to our working hypothesis based on a combined set of molecular data (mitochondrial markers COI and 16S, and nuclear markers ITS, 18S, and 28S), the traditional suborders Cleistocarpida (animals with claustrum) and Eleutherocarpida (animals without claustrum) are not monophyletic. Instead, our results show that staurozoans are divided into two groups, herein named Amyostaurida and Myostaurida, which can be distinguished by the absence/presence of interradial longitudinal muscles in the peduncle, respectively. We propose a taxonomic revision at the family and genus levels that preserves the monophyly of taxa. We provide a key for staurozoan genera and discuss the evolution of the main characters used in staurozoan taxonomy. PMID:27168970

  7. A blooming jellyfish in the northeast Atlantic and Mediterranean

    PubMed Central

    Licandro, P.; Conway, D. V. P.; Daly Yahia, M. N.; Fernandez de Puelles, M. L.; Gasparini, S.; Hecq, J. H.; Tranter, P.; Kirby, R. R.

    2010-01-01

    A long-term time series of plankton records collected by the continuous plankton recorder (CPR) Survey in the northeast Atlantic indicates an increased occurrence of Cnidaria since 2002. In the years 2007 and 2008, outbreaks of the warm-temperate scyphomedusa, Pelagia noctiluca, appeared in CPR samples between 45° N to 58° N and 1° W to 26° W. Knowing the biology of this species and its occurrence in the adjacent Mediterranean Sea, we suggest that P. noctiluca may be exploiting recent hydroclimatic changes in the northeast Atlantic to increase its extent and intensity of outbreaks. In pelagic ecosystems, Cnidaria can affect fish recruitment negatively. Since P. noctiluca is a highly venomous species, outbreaks can also be detrimental to aquaculture and make bathing waters unusable, thus having profound ecological and socio-economic consequences. PMID:20375044

  8. Early Life History of the 'Irukandji' Jellyfish Carukia barnesi.

    PubMed

    Courtney, Robert; Browning, Sally; Seymour, Jamie

    2016-01-01

    Adult medusae of Carukia barnesi were collected near Double Island, North Queensland Australia. From 73 specimens, 8 males and 15 females spawned under laboratory conditions. These gametes were artificially mixed which resulted in fertilized eggs. Post fertilization, most eggs developed to an encapsulated planula stage and then paused for between six days and six months prior to hatching as ciliated planulae. The paused stage planulae were negatively buoyant and adhered to substrate. The first planula was produced six days post fertilization, lacked larval ocelli, remained stationary, or moved very slowly for two days prior to metamorphosis into primary polyps. Mature polyps reproduced through asexual reproduction via lateral budding producing ciliated swimming polyps, which in turn settled and developed into secondary polyps. Medusae production for this species was in the form of monodisc strobilation, which left behind polyps able to continue asexual reproduction. PMID:26954781

  9. [Differential gene expression in the jellyfish Aurelia aurita].

    PubMed

    Matveev, I V

    2005-01-01

    The body of Aurelia aurita, as well as other diploblasts, consists of two epithelial layers: ectodermal and gastral epithelium. These two tissues are separated by mesoglea, or extracellular matrix. In most coelenterates mesoglea is acellular. In A. aurita mesogleal cells are scattered in mesoglea. Differential display PCR was used to compare mRNA pools from ectodermal epithelium, gastral epithelium and mesoglea. 4 novel gene fragments were cloned and sequenced. According to RTPCR results, one of these fragments is differentially expressed in the ectodermal epithelium. PMID:16706147

  10. Significant envenomation by Aurelia aurita, the moon jellyfish.

    PubMed

    Burnett, J W; Calton, G J; Larsen, J B

    1988-01-01

    The case of a patient envenomated by Aurelia aurita, who developed significant local cutaneous lesions and immunospecific serum antibodies is reported. The lesions required more than ten days to heal. The patient developed significant cross-reacting antibodies to Chrysaora quinquecirrha antigens. PMID:2896399

  11. Graviceptor development in jellyfish ephyrae in space and on Earth.

    PubMed

    Spangenberg, D B; Jernigan, T; Philput, C; Lowe, B

    1994-01-01

    Graviceptor (rhopalium) development in Aurelia aurita ephyrae which developed on Earth and in space during the nine-day NASA SLS-1 mission was compared. The space-developed ephyrae made graviceptors which were morphologically similar to those of their ground-based controls. Rhopalia of both groups developed statocysts with statoliths, ocelli, ciliated mechanoreceptor cells, and immature touch-plates with one type of hair cell. The number of rhopalia formed per arm of ephyrae of both groups revealed no significant differences. The number of statoliths formed per rhopalium was statistically higher in ephyrae which were induced to form in space with iodine than in L(Launch)+8h controls. Statolith numbers were not significantly different between Earth-formed control ephyrae and those formed from polyps induced on Earth and then sent into space 24h and 48h later. Statolith loss from rhopalia was significantly enhanced in the space-maintained ephyrae in ASW as compared to their controls. Ephyrae formed through thyroxine treatment and those maintained in thyroxine in space had statolith numbers comparable to thyroxine-treated controls. Pulsing abnormalities seen in some space-developed ephyrae suggest that some space-formed ephyrae may have developed abnormal rhopalia because normal rhopalia development and function is necessary for normal pulsing. PMID:11537934

  12. Graviceptor development in jellyfish ephyrae in space and on earth

    NASA Astrophysics Data System (ADS)

    Spangenberg, D. B.; Jernigan, T.; Philput, C.; Lowe, B.

    1994-08-01

    Graviceptor (rhopalium) development in Aurelia aurita ephyrae which developed on Earth and in space during the nine-day NASA SLS-1 mission was compared. The space-developed ephyrae made graviceptors which were morphologically similar to those of their ground-based controls. Rhopalia of both groups developed statocysts with statoliths, ocelli, ciliated mechanoreceptor cells, and immature touch-plates with one type of hair cell. The number of rhopalia formed per arm of ephyrae of both groups revealed no significant differences. The number of statoliths formed per rhopalium was statistically higher in ephyrae which were induced to form in space with iodine than in L(Launch)+8h controls. Statolith numbers were not significantly different between Earth-formed control ephyrae and those formed from polyps induced on Earth and then sent into space 24h and 48h later. Statolith loss from rhopalia was significantly enhanced in the space-maintained ephyrae in ASW as compared to their controls. Ephyrae formed through thyroxine treatment and those maintained in thyroxine in space had statolith numbers comparable to thyroxine-treated controls. Pulsing abnormalities seen in some space-developed ephyrae suggest that some space-formed ephyrae may have developed abnormal rhopalia because normal rhopalia development and function is necessary for normal pulsing.

  13. Graviceptor development in jellyfish ephyrae in space and on Earth

    NASA Technical Reports Server (NTRS)

    Spangenberg, D. B.; Jernigan, T.; Philput, C.; Lowe, B.

    1994-01-01

    Graviceptor (rhopalium) development in Aurelia aurita ephyrae which developed on Earth and in space during the nine-day NASA SLS-1 mission was compared. The space-developed ephyrae made graviceptors which were morphologically similar to those of their ground-based controls. Rhopalia of both groups developed statocysts with statoliths, ocelli, ciliated mechanoreceptor cells, and immature touch-plates with one type of hair cell. The number of rhopalia formed per arm of ephyrae of both groups revealed no significant differences. The number of statoliths formed per rhopalium was statistically higher in ephyrae which were induced to form in space with iodine than in L(Launch)+8h controls. Statolith numbers were not significantly different between Earth-formed control ephyrae and those formed from polyps induced on Earth and then sent into space 24h and 48h later. Statolith loss from rhopalia was significantly enhanced in the space-maintained ephyrae in artificial sea water (ASW) as compared to their controls. Ephyrae formed through thyroxine treatment and those maintained in thyroxine in space had statolith numbers comparable to thyroxine-treated controls. Pulsing abnormalitities seen in some space-developed ephyrae suggest that some space-formed ephyrae may have developed abnormal rhopalia because normal rhopalia development and function is necessary for normal pulsing.

  14. De Novo Assembly of the Transcriptome of Turritopsis, a Jellyfish that Repeatedly Rejuvenates.

    PubMed

    Hasegawa, Yoshinori; Watanabe, Takashi; Takazawa, Masaki; Ohara, Osamu; Kubota, Shin

    2016-08-01

    In most animals, aging is an irreversible process; however the species Turritopsis sp. has been observed to undergo a rejuvenation process as many as 14 times. In the present study, we used multiplexed RNA libraries to obtain the transcriptome from four developmental stages (St) of Turritopsis sp., including (I) immature medusa, (II) dumpling, (III) dumpling with a short stolon, and (IV) polyp, which had recently rejuvenated. A total of 4.02 billion paired-end reads were assembled de novo, yielding 90,327 contigs. Our analyses revealed that significant blast hits were recovered for 74% of the assembled contigs, and 19% were successfully annotated with gene ontology (GO) terms. A BLAST search demonstrated that 32% of the contigs were most similar to Hydra vulgarissequences. Raw reads from each sample were mapped against the contigs to find St-specific genes. This represents the first comprehensive set of de novo transcriptome data for this species, which may provide clues toward a better understanding of cyclical rejuvenation in multicellular animals. PMID:27498796

  15. Jellyfish and Ctenophore Blooms Coincide with Human Proliferations and Environmental Perturbations

    NASA Astrophysics Data System (ADS)

    Purcell, Jennifer E.

    2012-01-01

    Human populations have been concentrated along and exploiting the coastal zones for millennia. Of regions with the highest human impacts on the oceans ( Halpern et al. 2008 ), 6 of the top 10 have recently experienced blooms or problems with jellies. I review the time lines of human population growth and their effects on the coastal environment. I explore evidence suggesting that human activities - specifically, seafood harvest, eutrophication, hard substrate additions, transport of nonindigenous species, aquaculture, and climate change - may benefit jelly populations. Direct evidence is lacking for most of these factors; however, numerous correlations show abundant jellies in areas with warm temperatures and low forage fish populations. Jelly populations fluctuate in ˜10- and ˜20-year cycles in concert with solar and climate cycles. Global warming will provide a rising baseline against which climate cycles will cause fluctuations in jelly populations. The probable acceleration of anthropogenic effects may lead to further problems with jellies.

  16. Hunting in Bioluminescent Light: Vision in the Nocturnal Box Jellyfish Copula sivickisi.

    PubMed

    Garm, Anders; Bielecki, Jan; Petie, Ronald; Nilsson, Dan-Eric

    2016-01-01

    Cubomedusae all have a similar set of six eyes on each of their four rhopalia. Still, there is a great variation in activity patterns with some species being strictly day active while others are strictly night active. Here we have examined the visual ecology of the medusa of the night active Copula sivickisi from Okinawa using optics, morphology, electrophysiology, and behavioral experiments. We found the lenses of both the upper and the lower lens eyes to be image forming but under-focused, resulting in low spatial resolution in the order of 10-15°. The photoreceptor physiology is similar in the two lens eyes and they have a single opsin peaking around 460 nm and low temporal resolution with a flicker fusion frequency (fff) of 2.5 Hz indicating adaptions to vision in low light intensities. Further, the outer segments have fluid filled swellings, which may concentrate the light in the photoreceptor membrane by total internal reflections, and thus enhance the signal to noise ratio in the eyes. Finally our behavioral experiments confirmed that the animals use vision when hunting. When they are active at night they seek out high prey-concentration by visual attraction to areas with abundant bioluminescent flashes triggered by their prey. PMID:27065877

  17. Distribution, abundance, and predation effects of epipelagic ctenophores and jellyfish in the western Arctic Ocean

    NASA Astrophysics Data System (ADS)

    Purcell, Jennifer E.; Hopcroft, Russell R.; Kosobokova, Ksenia N.; Whitledge, Terry E.

    2010-01-01

    The Arctic Ocean is undergoing changes at an unprecedented rate because of global climate change. Especially poorly-studied in arctic waters are the gelatinous zooplankton, which are difficult to study using traditional oceanographic methods. A distinct zooplanktivore community was characterized in the surface 100 m by use of a Remotely Operated Vehicle, net collections, and SCUBA diving. The large scyphomedusa, Chrysaora melanaster, was associated with the warm Pacific water at ˜35-75 m depth. A diverse ctenophore community lived mainly above the C. melanaster layer, including Dryodora glandula, a specialized predator of larvaceans, Beroe cucumis, a predator of other ctenophores, and the extremely fragile Bolinopsis infundibulum, which was the most abundant species. Gut content analyses showed that Mertensia ovum selectively consumed the largest copepods ( Calanus spp.) and amphipods ( Parathemisto libellula); B. infundibulum consumed smaller copepods and pteropods ( Limacina helicina). Large copepods were digested by M. ovum in ˜12 h at -1.5 to 0 °C, but by B. infundibulum in only ˜4 h. We estimated that M. ovum consumed an average of ˜2% d -1 of the Calanus spp. copepods and that B. infundibulum consumed ˜4% d -1 of copepods <3 mm prosome length. These are significant consumption rates given that Calanus spp. have life-cycles of 2 or more years and are eaten by vertebrates including bowhead whales and arctic cod.

  18. Mating in the box jellyfish Copula sivickisi--Novel function of cnidocytes.

    PubMed

    Garm, Anders; Lebouvier, Marion; Tolunay, Duygu

    2015-09-01

    Within cubozoans, a few species have developed a sexual reproduction system including mating and internal fertilization. One species, Copula sivickisi, is found in a large area of the indo pacific. They have separate sexes and when mature males and females meet they entangle their tentacles and the males transfer a sperm package, a spermatozeugmata, which is ingested by the female fertilizing her eggs internally. After 2-3 days, the females lay an embryo strand that sticks to the substrate and after another 2-3 days, the fully developed larvae leave the strand. We have examined the ultrastructure of the gonads and spermatozeugmata to look for structural adaptations to this specialized way of reproduction and understand how the fertilization takes place. Surprisingly, we discovered that the male gonads were heavily packed with cnidocytes of the isorhiza type and that they are transferred to the spermatozeugmata. The spermatozeugmata does not dissolve in the female gastrovascular cavity but is attached to the female gonad probably using the isorhizas. Here, the sperm cells are partly digested and the nuclei are released. The actual fertilization seems to happen through phagocytosis of the released nuclei by the epithelial cells. The female gonads are likewise packed with cnidocytes but of the eurytele type. They do not mature inside the female and putatively serve to protect the developing larvae once the embryo strand is laid. This specialized way of fertilization is to our knowledge novel and so is this first account of cnidocytes being directly involved in cnidarian reproduction. PMID:26010863

  19. Estimating digestion rate and the problem of individual variability, exemplified by a scyphozoan jellyfish.

    PubMed

    Båmstedt; Martinussen

    2000-08-23

    Short-term (h) and long-term (days) individual variability and the effects of momentary change in feeding intensity on digestion time were studied in the scyphomedusa Aurelia aurita as a basis for developing a method to experimentally measure the digestion rate with a high precision. Ten individual medusae showed only small, non-significant differences in average digestion time (range, 2.1-2.5 h at 10 degrees C) over a 9-day experiment, whereas variability within and between days and between individuals at a given occasion was high. When medusae were manually kept at a constant feeding intensity, stomach fullness showed high variability both between individuals and within an individual over time. With a feeding intensity of, respectively, 1, 2, 4 and 8 prey h(-1) over a 5-h experimental period, stomach fullness of most individuals corresponded to a theoretical digestion time of 1-3 h, whereas single meals of the same size usually gave somewhat higher digestion time. Medusae subject to a switching from a low to a high feeding intensity tended to increase the variability, but most individuals showed a digestion time of 1-3 h. An opposite switching tended to increase the digestion time and its variability. It is concluded that the digestion time of A. aurita is randomly variable over time within given limits for a given food and environmental condition. This variability is non-synchronised in the population, causing high variability between individuals, and changes in the feeding intensity cause additional variability. However, the average digestion time of A. aurita in a physically and nutritionally stable environment is robust, and changes in the feeding intensity give predictable effects. The use of field collected data on stomach contents and laboratory determined digestion times is therefore an attractive method to calculate predation rate, but the inherent high variability in digestion time must be taken into consideration when designing the digestion experiments. Based on these findings a simple experimental method to determine the digestion time of aquatic animals is outlined and evaluated. The digestion time is simply given as the ratio between number of prey in stomach and total number of prey eaten, times the incubation time, assuming that the feeding intensity is constant. PMID:10958898

  20. Jellyfish and ctenophore blooms coincide with human proliferations and environmental perturbations.

    PubMed

    Purcell, Jennifer E

    2012-01-01

    Human populations have been concentrated along and exploiting the coastal zones for millennia. Ofregions with the highest human impacts on the oceans (Halpern et al. 2008), 6 of the top 10 have recently experienced blooms or problems with jellies. I review the time lines of human population growth and their effects on the coastal environment. I explore evidence suggesting that human activities--specifically, seafood harvest, eutrophication, hard substrate additions, transport ofnonindigenous species, aquaculture, and climate change--may benefit jelly populations. Direct evidence is lacking for most of these factors; however, numerous correlations show abundant jellies in areas with warm temperatures and low forage fish populations. Jelly populations fluctuate in approximately 10- and approximately 20-year cycles in concert with solar and climate cycles. Global warming will provide a rising baseline against which climate cycles will cause fluctuations in jelly populations. The probable acceleration of anthropogenic effects may lead to further problems with jellies. PMID:22457974

  1. Optical properties of the iridescent organ of the comb-jellyfish Beroë cucumis (Ctenophora)

    NASA Astrophysics Data System (ADS)

    Welch, Victoria; Vigneron, Jean Pol; Lousse, Virginie; Parker, Andrew

    2006-04-01

    Using transmission electron microscopy, analytical modeling, and detailed numerical simulations, the iridescence observed from the comb rows of the ctenophore Beroë cucumis was investigated. It is shown that the changing coloration which accompanies the beating of comb rows as the animal swims can be explained by the weakly-contrasted structure of the refractive index induced by the very coherent packing of locomotory cilia. The colors arising from the narrow band-gap reflection are shown to be highly saturated and, as a function of the incidence angle, cover a wide range of the visible and ultraviolet spectrum. The high transparency of the structure at the maximal bioluminescence wavelength is also explained.

  2. Significance of different microalgal species for growth of moon jellyfish ephyrae, Aurelia sp.1

    NASA Astrophysics Data System (ADS)

    Zheng, Shan; Sun, Xiaoxia; Wang, Yantao; Sun, Song

    2015-10-01

    The scyphozoan Aurelia aurita (Linnaeus) sp. l., is a cosmopolitan species-complex which blooms seasonally in a variety of coastal and shelf sea environments around the world. The effects of different microalgal species on the growth of newly-released Aurelia sp.1 ephyrae were studied under laboratory conditions. We fed ephyrae with four different microalgal species (diatom, autotrophic dinoflagellate, heterotrophic dinoflagellate, and chlorophyta) plus Artemia nauplii for 12-24 d at 18°C. Results showed that the growth rate diverged significantly for Artemia nauplii compared to other food types. In addition, there was no significant variation between the growth rates for Skeletonema costatum and Prorocentrum donghaiense, and no significant variation was found in the growth rates for N. scintillans and P. subcordiformis. Artemia nauplii could support the energy requirement for the newly-released ephyrae to develop to meduase, and the ephyrae with Artemia nauplii showed a significant average growth rate of 25.85% d-1. Newly-released ephyrae could grow slightly with some species of microalgae in the earliest development stage. Chain diatom Skeletonema costatum and autotrophic dinoflagellate Prorocentrum donghaiense, could not support the growth of the ephyrae, while heterotrophic dinoflagellate Noctiluca scintillans and chlorophyta Platymonas subcordiformis could support the growth of the ephyrae. However, none of the ephyrae fed with the tested phytoplankton could mature to medusae.

  3. The conserved mitochondrial gene distribution in relatives of Turritopsis nutricula, an immortal jellyfish

    PubMed Central

    Devarapalli, Pratap; Kumavath, Ranjith N; Barh, Debmalya; Azevedo, Vasco

    2014-01-01

    Turritopsis nutricula (T. nutricula) is the one of the known reported organisms that can revert its life cycle to the polyp stage even after becoming sexually mature, defining itself as the only immortal organism in the animal kingdom. Therefore, the animal is having prime importance in basic biological, aging, and biomedical researches. However, till date, the genome of this organism has not been sequenced and even there is no molecular phylogenetic study to reveal its close relatives. Here, using phylogenetic analysis based on available 16s rRNA gene and protein sequences of Cytochrome oxidase subunit-I (COI or COX1) of T. nutricula, we have predicted the closest relatives of the organism. While we found Nemopsis bachei could be closest organism based on COX1 gene sequence; T. dohrnii may be designated as the closest taxon to T. nutricula based on rRNA. Moreover, we have figured out four species that showed similar root distance based on COX1 protein sequence. PMID:25352727

  4. The conserved mitochondrial gene distribution in relatives of Turritopsis nutricula, an immortal jellyfish.

    PubMed

    Devarapalli, Pratap; Kumavath, Ranjith N; Barh, Debmalya; Azevedo, Vasco

    2014-01-01

    Turritopsis nutricula (T. nutricula) is the one of the known reported organisms that can revert its life cycle to the polyp stage even after becoming sexually mature, defining itself as the only immortal organism in the animal kingdom. Therefore, the animal is having prime importance in basic biological, aging, and biomedical researches. However, till date, the genome of this organism has not been sequenced and even there is no molecular phylogenetic study to reveal its close relatives. Here, using phylogenetic analysis based on available 16s rRNA gene and protein sequences of Cytochrome oxidase subunit-I (COI or COX1) of T. nutricula, we have predicted the closest relatives of the organism. While we found Nemopsis bachei could be closest organism based on COX1 gene sequence; T. dohrnii may be designated as the closest taxon to T. nutricula based on rRNA. Moreover, we have figured out four species that showed similar root distance based on COX1 protein sequence. PMID:25352727

  5. Jellyfish: Evidence of Extreme Ram-pressure Stripping in Massive Galaxy Clusters

    NASA Astrophysics Data System (ADS)

    Ebeling, H.; Stephenson, L. N.; Edge, A. C.

    2014-02-01

    Ram-pressure stripping by the gaseous intracluster medium has been proposed as the dominant physical mechanism driving the rapid evolution of galaxies in dense environments. Detailed studies of this process have, however, largely been limited to relatively modest examples affecting only the outermost gas layers of galaxies in nearby and/or low-mass galaxy clusters. We here present results from our search for extreme cases of gas-galaxy interactions in much more massive, X-ray selected clusters at z > 0.3. Using Hubble Space Telescope snapshots in the F606W and F814W passbands, we have discovered dramatic evidence of ram-pressure stripping in which copious amounts of gas are first shock compressed and then removed from galaxies falling into the cluster. Vigorous starbursts triggered by this process across the galaxy-gas interface and in the debris trail cause these galaxies to temporarily become some of the brightest cluster members in the F606W passband, capable of outshining even the Brightest Cluster Galaxy. Based on the spatial distribution and orientation of systems viewed nearly edge-on in our survey, we speculate that infall at large impact parameter gives rise to particularly long-lasting stripping events. Our sample of six spectacular examples identified in clusters from the Massive Cluster Survey, all featuring M F606W < -21 mag, doubles the number of such systems presently known at z > 0.2 and facilitates detailed quantitative studies of the most violent galaxy evolution in clusters. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. These observations are associated with programs GO-10491, -10875, -12166, and -12884.

  6. Rock preference of planulae of jellyfish Aurelia aurita (Linnaeus 1758) for settlement in the laboratory

    NASA Astrophysics Data System (ADS)

    Yoon, Won Duk; Choi, Sung-Hwan; Han, Changhoon; Park, Won Gyu

    2014-06-01

    Planulae of Aurelia aurita were exposed to 11 types of rocks (basalt, gabbro, granite, rhyolite, sandstone, limestone, conglomerate, gneiss, quartzite, marble and schist) to examine their attachment preference among rock material and position. Numbers of attached polyps was the highest on marble and the least on limestone. Their preference with regard to settling position was the same among the rocks, showing the highest density of polyps on the underside (88.5%) compared to upper (23.6%) and perpendicular sides (10.3%) of rock. The results showed that while position preference is more important than rock property, higher numbers of polyps were observed in rocks with a medium surface hardness.

  7. JELLYFISH: EVIDENCE OF EXTREME RAM-PRESSURE STRIPPING IN MASSIVE GALAXY CLUSTERS

    SciTech Connect

    Ebeling, H.; Stephenson, L. N.; Edge, A. C.

    2014-02-01

    Ram-pressure stripping by the gaseous intracluster medium has been proposed as the dominant physical mechanism driving the rapid evolution of galaxies in dense environments. Detailed studies of this process have, however, largely been limited to relatively modest examples affecting only the outermost gas layers of galaxies in nearby and/or low-mass galaxy clusters. We here present results from our search for extreme cases of gas-galaxy interactions in much more massive, X-ray selected clusters at z > 0.3. Using Hubble Space Telescope snapshots in the F606W and F814W passbands, we have discovered dramatic evidence of ram-pressure stripping in which copious amounts of gas are first shock compressed and then removed from galaxies falling into the cluster. Vigorous starbursts triggered by this process across the galaxy-gas interface and in the debris trail cause these galaxies to temporarily become some of the brightest cluster members in the F606W passband, capable of outshining even the Brightest Cluster Galaxy. Based on the spatial distribution and orientation of systems viewed nearly edge-on in our survey, we speculate that infall at large impact parameter gives rise to particularly long-lasting stripping events. Our sample of six spectacular examples identified in clusters from the Massive Cluster Survey, all featuring M {sub F606W} < –21 mag, doubles the number of such systems presently known at z > 0.2 and facilitates detailed quantitative studies of the most violent galaxy evolution in clusters.

  8. Jellyfish Lake, Palau: early diagenesis of organic matter in sediments of an anoxic marine lake

    USGS Publications Warehouse

    Orem, W.H.; Burnett, W.C.; Landing, W.M.; Lyons, W.B.; Showers, W.

    1991-01-01

    The major postdepositional change in the sedimentary organic matter is carbohydrate biodegradation. Lignin and aliphatic substances are preserved in the sediments. Dissolved organic matter in pore waters is primarily composed of carbohydrates, reflecting the degradation of sedimentary carbohydrates. Rate constants for organic carbon degradation and sulfate reduction in sediments of the lake are about 10?? lower than in other anoxic sediments. This may reflect the vascular plant source and partly degraded nature of the organic matter reaching the sediments of the lake. -from Authors

  9. Early Life History of the ‘Irukandji’ Jellyfish Carukia barnesi

    PubMed Central

    Browning, Sally

    2016-01-01

    Adult medusae of Carukia barnesi were collected near Double Island, North Queensland Australia. From 73 specimens, 8 males and 15 females spawned under laboratory conditions. These gametes were artificially mixed which resulted in fertilized eggs. Post fertilization, most eggs developed to an encapsulated planula stage and then paused for between six days and six months prior to hatching as ciliated planulae. The paused stage planulae were negatively buoyant and adhered to substrate. The first planula was produced six days post fertilization, lacked larval ocelli, remained stationary, or moved very slowly for two days prior to metamorphosis into primary polyps. Mature polyps reproduced through asexual reproduction via lateral budding producing ciliated swimming polyps, which in turn settled and developed into secondary polyps. Medusae production for this species was in the form of monodisc strobilation, which left behind polyps able to continue asexual reproduction. PMID:26954781

  10. First record of encysted metacercariae in hydrozoan jellyfishes and ctenophores of the southern Atlantic.

    PubMed

    Martorelli, S R

    1996-04-01

    Three species of pelagic coelenterates and ctenophores captured in Mar del Plata port, Buenos Aires, Argentina, were examined for digenean parasites. Encysted metacercariae were observed and collected. Cysts were found in the mesoglea of the hydromedusae Phialidium sp. and Liriope tetraphylla, and in the ectenophore Mnemiopsis macradyi. The morphology of the worms resembles that of the lepocreadiid digeneans. This is the first record for a metacercaria encysted in hydromedusae or ctenophores. PMID:8604116

  11. Hunting in Bioluminescent Light: Vision in the Nocturnal Box Jellyfish Copula sivickisi

    PubMed Central

    Garm, Anders; Bielecki, Jan; Petie, Ronald; Nilsson, Dan-Eric

    2016-01-01

    Cubomedusae all have a similar set of six eyes on each of their four rhopalia. Still, there is a great variation in activity patterns with some species being strictly day active while others are strictly night active. Here we have examined the visual ecology of the medusa of the night active Copula sivickisi from Okinawa using optics, morphology, electrophysiology, and behavioral experiments. We found the lenses of both the upper and the lower lens eyes to be image forming but under-focused, resulting in low spatial resolution in the order of 10–15°. The photoreceptor physiology is similar in the two lens eyes and they have a single opsin peaking around 460 nm and low temporal resolution with a flicker fusion frequency (fff) of 2.5 Hz indicating adaptions to vision in low light intensities. Further, the outer segments have fluid filled swellings, which may concentrate the light in the photoreceptor membrane by total internal reflections, and thus enhance the signal to noise ratio in the eyes. Finally our behavioral experiments confirmed that the animals use vision when hunting. When they are active at night they seek out high prey-concentration by visual attraction to areas with abundant bioluminescent flashes triggered by their prey. PMID:27065877

  12. Evolution of box jellyfish (Cnidaria: Cubozoa), a group of highly toxic invertebrates

    PubMed Central

    Bentlage, Bastian; Cartwright, Paulyn; Yanagihara, Angel A.; Lewis, Cheryl; Richards, Gemma S.; Collins, Allen G.

    2010-01-01

    Cubozoa (Cnidaria: Medusozoa) represents a small clade of approximately 50 described species, some of which cause serious human envenomations. Our understanding of the evolutionary history of Cubozoa has been limited by the lack of a sound phylogenetic hypothesis for the group. Here, we present a comprehensive cubozoan phylogeny based on ribosomal genes coding for near-complete nuclear 18S (small subunit) and 28S (large subunit) and partial mitochondrial 16S. We discuss the implications of this phylogeny for our understanding of cubozoan venom evolution, biogeography and life-history evolution. Our phylogenetic hypothesis suggests that: (i) the last common ancestor of Carybdeida probably possessed the mechanism(s) underlying Irukandji syndrome, (ii) deep divergences between Atlantic and Indo-Pacific clades may be explained by ancient vicariant events, and (iii) sexual dimorphism evolved a single time in concert with complex sexual behaviour. Furthermore, several cubozoan taxa are either para- or polyphyletic, and we address some of these taxonomic issues by designating a new family, Carukiidae, a new genus, Copula, and by redefining the families Tamoyidae and Tripedaliidae. Lastly, cubozoan species identities have long been misunderstood and the data presented here support many of the recent scientific descriptions of cubozoan species. However, the results of a phylogeographic analysis of Alatina moseri from Hawai'i and Alatina mordens from Australia indicate that these two nominal species represent a single species that has maintained metapopulation cohesion by natural or anthropogenic dispersal. PMID:19923131

  13. Into the Curriculum. Dramatics/Reading/Language Arts: Jellyfish Jiggle and More; Reading/Language Arts: Birthstone Folklore; Science: Jellyfish FAQ; Science: Minerals in Caves; Social Studies: Mapping the Oceans.

    ERIC Educational Resources Information Center

    School Library Media Activities Monthly, 2003

    2003-01-01

    Provides five fully developed library media activities that are designed for use with specific curriculum units in dramatics, reading, language arts, science, and social studies. Library media skills, curriculum objectives, grade levels, resources, instructional roles, activities and procedures, evaluation, and follow-up are describes for each…

  14. Reproduction of the giant jellyfish, Nemopilema nomurai (Scyphozoa: Rhizostomeae), in 2006-2008 as peripherally-transported populations

    NASA Astrophysics Data System (ADS)

    Iguchi, Naoki; Lee, Hye Eun; Yoon, Won Duk; Kim, Suam

    2010-06-01

    This study investigated the sexual maturation process, release of spermatozoa or eggs and oocyte diameter of the rhizostomid medusae Nemopilema nomurai using samples collected from August 2006 to June 2008 from the waters around Korea and Japan, including peripheral areas outside the species’ usual habitat. Immature medusae were observed from June to October only in the western sector of the study area. The onset of spermatozoa and egg release occurred in September and October, respectively, and peaked in December and January. Medusae migrated eastward from source areas with the Tsushima Warm Current, where they formed gametes and spawned. Peak position and maximum oocyte diameter increased as the gonads developed according to the size-frequency distribution of oocytes. No fertilized eggs or embryos were found in the gonads. The correlation was analyzed with bell diameter, maximum oocyte diameter, sampling date, surface water temperature and gonad color to estimate which environmental factors and maturation indices were related to the maturation stage of females. Maturation stage correlated well with maximum oocyte diameter, which correlated negatively with surface water temperature. There was no significant correlation between bell diameter and maturation stage. Therefore, bell diameter was inappropriate for determining maturation index. Sex could not be distinguished clearly by gonad color. However, light pink gonads were more prevalent in males and various deep colors such as orange and brown were more frequent in female medusae.

  15. On the Frontier of the Hunt for Jellyfish Galaxies: Ram-Pressure Stripping in the Hubble Frontier Fields

    NASA Astrophysics Data System (ADS)

    McPartland, Conor; Ebeling, Harald

    2015-08-01

    Using quantitative morphological selection criteria, we search for evidence of galaxies experiencing ram-pressure stripping (RPS) in the Hubble Frontier Fields. The broader areal coverage of these clusters, provided by the complementary parallel fields, allow us to sample regions near to the expected stripping radius of the cluster (˜1 Mpc), where we expect to find the highest density of events. Expanding the number of known events (especially at large cluster-centric radii) will allow us to disentangle the relative contributions of "normal" galaxy infall and cluster mergers in producing the events we observe. We present observational characteristics of the best RPS candidates from the Frontier Fields. Finally, we use these objects, along with RPS events previously identified in the literature, to make quantitative comparisons with predictions of theoretical and numerical models of ram-pressure stripping.

  16. Transient-state kinetic analysis of complex formation between photoprotein clytin and GFP from jellyfish Clytia gregaria.

    PubMed

    Eremeeva, Elena V; van Berkel, Willem J H; Vysotski, Eugene S

    2016-02-01

    Luminous organisms use different protein-mediated strategies to modulate light emission color. Here, we report the transient-state kinetic studies of the interaction between photoprotein clytin from Clytia gregaria and its antenna protein, cgreGFP. We propose that cgreGFP forms a transient complex with Ca(2+)-bound clytin before the excited singlet state of the coelenteramide product is formed. From the spectral distribution and donor-acceptor separation distance, we infer that clytin reaction intermediates may interact only with the middle side part of cgreGFP. PMID:26867648

  17. Patterns of trace element bioaccumulation in jellyfish Rhizostoma pulmo (Cnidaria, Scyphozoa) in a Mediterranean coastal lagoon from SE Spain.

    PubMed

    Muñoz-Vera, Ana; Peñas Castejón, Jose Matías; García, Gregorio

    2016-09-15

    The effects of an abandoned mining area, exploited for centuries in the mining district of Cartagena-La Union, result in a continuous supply of heavy metals into the Mar Menor coastal lagoon after rain episodes. As a consequence, concentration of trace elements in water column and sediments of this ecosystem is usually higher than in other areas. For monitoring ecosystem health, this study assessed the ability of Rhizostoma pulmo to bioaccumulate trace elements. A total of 57 individuals were sampled at eight different sampling stations during the summer of 2012. Although the concentrations of different analyzed elements (Al, Ti, Cr, Mn, Fe, Ni, Cu, Zn, As, Cd, Sn, and Pb) were moderate, bioconcentration levels in relation to seawater metal concentration were extremely high. In any case, the use or disposal of these organisms should consider their metal content, because of their potential environmental and health implications. PMID:27376999

  18. Checkpoints in the life-cycle of Cassiopea spp.: control of metagenesis and metamorphosis in a tropical jellyfish.

    PubMed

    Hofmann, D K; Fitt, W K; Fleck, J

    1996-02-01

    Experimental data reveal that most, if not all, major events in the metagenetic life-cycle of Cassiopea spp. at these checkpoints depend on the interaction with specific biotic and physical cues. For medusa formation within a permissive temperature range by monodisk strobilation of the polyp, the presence of endosymbiotic dinoflagellates is indispensable. The priming effect of the algal symbionts is not primarily coupled with photosynthetic activity, but was found to be enhanced in the light. Budding of larva-like propagules by the polyp, however, is independent from such zooxanthellae. On the other hand the budding rate is influenced by various rearing conditions. Exogenous chemical cues control settlement and metamorphosis into scyphopolyps of both sexually produced planula larvae and asexual propagules. In laboratory experiments two classes of metamorphosis inducing compounds have been detected: a family of oligopeptides, featuring a proline-residue next to the carboxyterminal amino acid, and several phorbol esters. Using the peptide 14C-DNS-GPGGPA, induction of metamorphosis has been shown to be receptor-mediated. Furthermore, activation of protein kinase C, a key enzyme within the inositolphospholipid-signalling pathway appears to be involved in initiating metamorphosis. In mangrove habitats of Cassiopea spp. planula larvae specifically settle and metamorphose on submerged, deteriorating mangrove leaves from which biologically active fractions have been isolated. The chemical characterisation and comparison of these compounds from the natural environment with the properties and mode of action of oligopeptide inducers is in progress. PMID:8735945

  19. Abundance, seasonal patterns and diet of the non-native jellyfish Blackfordia virginica in a Portuguese estuary

    NASA Astrophysics Data System (ADS)

    Marques, F.; Chainho, P.; Costa, J. L.; Domingos, I.; Angélico, M. M.

    2015-12-01

    Blackfordia virginica, a non-indigenous hydrozoan introduced in many systems around the world, has been observed in the Mira estuary, southwest of Portugal, since 1984. Monthly sampling (January 2013-January 2014) at a fixed location with high abundance of the medusae confirmed the occurrence of a seasonal cycle associated with temperature and photoperiod. The beginning of the medusa cycle occurred in May immediately after the spring zooplankton bloom during April. Examination of the gut contents of B. virginica medusae revealed that copepods, the most abundant group in the zooplankton community, were highly predated. Barnacle nauplii, decapod crustacean larvae and anchovy eggs were also identified in the guts. The medusae showed positive selection for copepods, and negative selection for barnacle nauplii, decapod crustacean larvae and anchovy eggs. The mortality rate of copepods (used as a model prey group) induced by medusae predation was estimated and showed the potential impact of this species in the ecosystem, ranging between 2.34 d-1 and 0.02 d-1, with a minimum copepod half-life of 0.30 days.

  20. Energetics of jellyfish locomotion determined from field measurements using a Self-Contained Underwater Velocimetry Apparatus (SCUVA)

    NASA Astrophysics Data System (ADS)

    Katija, Kakani; Dabiri, John O.

    2007-11-01

    We describe the development and application of a Self-Contained Underwater Velocimetry Apparatus (SCUVA), which enables a single SCUBA diver to make DPIV measurements of animal-fluid interactions in the field. The device is used to study Aurelia labiata swimming in the coastal waters of Long Beach, California. SCUVA measurements of animals over a range of sizes are used to directly quantify the kinetic energy in the flow field induced by the swimming motions of individual medusae and are compared with existing theoretical models. The method provides details regarding the temporal evolution of the energetics during the swimming cycle and their scaling with bell diameter. These types of measurements will allow for the determination of propulsive efficiency, which can be used to compare various methods of biological propulsion.

  1. 50 CFR 217.114 - Mitigation.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... moving away from the mission area. (iii) If large Sargassum rafts or large concentrations of jellyfish... jellyfish that caused the postponement are confirmed to be outside of the safety zone due to the current...

  2. 50 CFR 217.84 - Mitigation.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... concentrations of fish, jellyfish, and/or large Sargassum rafts are observed within the mitigation-monitoring zone. The delay would continue until the fish, jellyfish, and/or Sargassum rafts that cause the... birds, large concentrations of fish or jellyfish, and large Sargassum mats. The presence of diving...

  3. 50 CFR 217.84 - Mitigation.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... concentrations of fish, jellyfish, and/or large Sargassum rafts are observed within the mitigation-monitoring zone. The delay would continue until the fish, jellyfish, and/or Sargassum rafts that cause the... birds, large concentrations of fish or jellyfish, and large Sargassum mats. The presence of diving...

  4. 50 CFR 217.84 - Mitigation.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... concentrations of fish, jellyfish, and/or large Sargassum rafts are observed within the mitigation-monitoring zone. The delay would continue until the fish, jellyfish, and/or Sargassum rafts that cause the... birds, large concentrations of fish or jellyfish, and large Sargassum mats. The presence of diving...

  5. Investigations of combinations of mutations in the jellyfish green fluorescent protein (GFP) that afford brighter fluorescence, and use of a version (VisGreen) in plant, bacterial, and animal cells.

    PubMed

    Teerawanichpan, Prapapan; Hoffman, Travis; Ashe, Paula; Datla, Raju; Selvaraj, Gopalan

    2007-09-01

    Among the GFPs used for imaging green fluorescence, the Emerald version has been considered the best GFP to use but there is no formal report on its construction or the relevance of the amino acid (aa) substitutions in it relative to the commonly used GFPs. Here, we have shown that a version of Emerald makes Escherichia coli host cells visibly green even under dim room light conditions. Exploiting this feature, we have determined for the first time whether the changes in the structure of Emerald protein brought about by the aa substitutions are all indeed essential for brightness. F64L and S72A accompanying the classical S65T substitution on the chromophore-bearing helix are essential. Two amino acid changes, one on the surface (N149K) of the beta barrel that encases the helix and the other (I167T) near the chromophore enhance the visible green colour individually and additively when present together. The other two substitutions, M153T (on the surface) and H231L (on the surface), do not contribute to the visible green phenotype, even though in earlier studies M153T has been reported to enhance GFP fluorescence. The GFP version with F64L-S65T-S72A-N149K-I167T is referred to as VisGreen. We found VisGreen and Emerald to be indistinguishable in their quantum yield, molar extinction coefficient, folding efficiency, or photosensitivity. VisGreen rendered bacterial, plant, and animal cells highly fluorescent. Interestingly, N149K in the above combination was not essential to render bacterial cells highly fluorescent. PMID:17658219

  6. Dynamic Model for Life History of Scyphozoa

    PubMed Central

    Xie, Congbo; Fan, Meng; Wang, Xin; Chen, Ming

    2015-01-01

    A two-state life history model governed by ODEs is formulated to elucidate the population dynamics of jellyfish and to illuminate the triggering mechanism of its blooms. The polyp-medusa model admits trichotomous global dynamic scenarios: extinction, polyps survival only, and both survival. The population dynamics sensitively depend on several biotic and abiotic limiting factors such as substrate, temperature, and predation. The combination of temperature increase, substrate expansion, and predator diminishment acts synergistically to create a habitat that is more favorable for jellyfishes. Reducing artificial marine constructions, aiding predator populations, and directly controlling the jellyfish population would help to manage the jellyfish blooms. The theoretical analyses and numerical experiments yield several insights into the nature underlying the model and shed some new light on the general control strategy for jellyfish. PMID:26114642

  7. Dynamic Model for Life History of Scyphozoa.

    PubMed

    Xie, Congbo; Fan, Meng; Wang, Xin; Chen, Ming

    2015-01-01

    A two-state life history model governed by ODEs is formulated to elucidate the population dynamics of jellyfish and to illuminate the triggering mechanism of its blooms. The polyp-medusa model admits trichotomous global dynamic scenarios: extinction, polyps survival only, and both survival. The population dynamics sensitively depend on several biotic and abiotic limiting factors such as substrate, temperature, and predation. The combination of temperature increase, substrate expansion, and predator diminishment acts synergistically to create a habitat that is more favorable for jellyfishes. Reducing artificial marine constructions, aiding predator populations, and directly controlling the jellyfish population would help to manage the jellyfish blooms. The theoretical analyses and numerical experiments yield several insights into the nature underlying the model and shed some new light on the general control strategy for jellyfish. PMID:26114642

  8. Marine envenomations and aquatic dermatology.

    PubMed

    Soppe, G G

    1989-08-01

    Jellyfish stings are usually mild except those caused by species in the South Pacific. The box jellyfish can produce a severe cardiorespiratory insult. The sting of the Portuguese man-of-war is more potent than that of the common jellyfish. The Indo-Pacific area is the source of the most venomous bony fish. Many injuries can be avoided by wearing shoes when walking in shallow water or tide pools. Aquatic-related skin infections may involve unusual organisms. Swimmer's itch, a disease of freshwater bathing, is caused by cercariae. Seabather's eruption produces a rash in swimsuit-covered areas; the etiology is not clear. PMID:2569260

  9. An experimental study of Aurelia aurita feeding behaviour: Inference of the potential predation impact on a temperate estuarine nursery area

    NASA Astrophysics Data System (ADS)

    Pereira, Rita; Teodósio, Maria Alexandra; Garrido, Susana

    2014-06-01

    Temperate estuaries are nursery areas for economically important fisheries resources. The common jellyfish Aurelia aurita is a resident species in many of these areas, where it can reach high abundances. This work aimed to determine the potential for predation of A. aurita on zooplanktonic organisms and early life stages of fishes, measuring feeding rates at concentrations that mimic those occurring for zooplankton, fish eggs and larvae in an estuarine nursery area. A set of experiments was aimed at determining the feeding selectivity of jellyfish when offered a mixture of fish eggs and larvae and wild plankton. Clearance rates varied markedly with prey availability and concentrations. When given mixtures of different prey types, jellyfish preferentially elected some taxa (copepods and fish eggs). Data obtained in the laboratory experiments were used to infer the potential impact of jellyfish predation upon zooplankton and ichthyoplankton in the Guadiana estuary (Southern Iberia). Repeated sampling of zooplankton, fish eggs and medusae was undertaken during the summer season of 2011. Abundance determinations were combined with experimentally estimated clearance rates of individual medusa to infer the potential jellyfish-induced mortality on prey in the area. In June and early August jellyfish-induced mortality rates were very high, and half-life times (t1/2) were consequently short for the zooplankton and ichthyoplankton. Although the potentially overestimation of our feeding rates typical of confined laboratory experiments, the results show high ingestion and clearance rates at high temperatures, typical from summer condition, and results also suggest that either by predation on early life stages of fish, or by competition for food resources, jellyfish may have a significant impact on estuarine communities and its nursery function.

  10. Effect of silver nanoparticles on marine organisms belonging to different trophic levels.

    PubMed

    Gambardella, Chiara; Costa, Elisa; Piazza, Veronica; Fabbrocini, Adele; Magi, Emanuele; Faimali, Marco; Garaventa, Francesca

    2015-10-01

    Silver nanoparticles (Ag-NPs) are increasingly used in a wide range of consumer products and such an extensive use raises questions about their safety and environmental toxicity. We investigated the potential toxicity of Ag-NPs in the marine ecosystem by analyzing the effects on several organisms belonging to different trophic levels. Algae (Dunaliella tertiolecta, Skeletonema costatum), cnidaria (Aurelia aurita jellyfish), crustaceans (Amphibalanus amphitrite and Artemia salina) and echinoderms (Paracentrotus lividus) were exposed to Ag-NPs and different end-points were evaluated: algal growth, ephyra jellyfish immobilization and frequency of pulsations, crustaceans mortality and swimming behavior, and sea urchin sperm motility. Results showed that all the end-points were able to underline a dose-dependent effect. Jellyfish were the most sensitive species, followed by barnacles, sea urchins, green algae, diatoms and brine shrimps. In conclusion, Ag-NPs exposure can influence different trophic levels within the marine ecosystem. PMID:26065810

  11. Learning about Marine Biology. Superific Science Book VI. A Good Apple Science Activity Book for Grades 5-8+.

    ERIC Educational Resources Information Center

    Conway, Lorraine

    Based on the assumption that most students have a natural curiosity about the plant and animal life residing in the oceans, this document provides students in grades five through eight with activities in marine biology. The book provides illustrated information and learning activities dealing with: (1) diatoms; (2) the life cycle of the jellyfish;…

  12. The Science of Museums: Tapping the Social Sciences to Make Exhibits Fathomable and Fun.

    ERIC Educational Resources Information Center

    Raloff, Janet

    1998-01-01

    The most successful science-and-technology center exhibits owe as much to the evaluation of visitor reactions as they do to budgets and planning. Explores different types of visitor-evaluation studies and shares examples of successful exhibit designs built upon visitor evaluations, including children's physics exhibits and jellyfish as living art.…

  13. Proceedings of the Annual Meeting of the Association for Education in Journalism and Mass Communication (80th, Chicago, Illinois, July 30-August 2, 1997): Law.

    ERIC Educational Resources Information Center

    Association for Education in Journalism and Mass Communication.

    The Law section of the Proceedings contains the following 10 papers: "Protection without a Shield: Revisiting the Journalist's Common Law Privilege" (Laurence B. Alexander); "Burning the Global Village: The Constitutionality of State Laws Regulating Indecency in Cyberspace" (Dolores L. Flamiano); "Of Jellyfish and Community Leaders: Redefining the…

  14. Filling a GAP-An Optimized Probe for ER Ca(2+) Imaging In Vivo.

    PubMed

    Malli, Roland; Eroglu, Emrah; Waldeck-Weiermair, Markus; Graier, Wolfgang F

    2016-06-23

    In this issue of Cell Chemical Biology, Navas-Navarro et al. (2016) demonstrate that fusion of engineered derivatives of the long-known jellyfish proteins green fluorescent protein (GFP) and aequorin yield optimized genetically encoded fluorescent probes for detecting Ca(2+) signals within the endoplasmic reticulum (ER) of living animals. PMID:27341431

  15. A Fluid-solid Numerical Model for the Analysis of Bio-inspired UUV

    NASA Astrophysics Data System (ADS)

    Mitra, Santanu; Krishnamurthy, Nagendra; Tafti, Danesh; Priya, Shashank

    2012-11-01

    This research will describe how a biology-inspired approach to engineering has placed jellyfish at the center of efforts to build next-generation underwater vehicles. In order to swim, jellyfish contract the circular muscles that line the undersurface of their bell. The motion of the bell from the relaxed position to the fully contracted position results in the mesoglea interacting with the surrounding water in such a way that causes the jellyfish to move forward. The present method uses two-dimensional fluid elements and plain strain hyperelastic structural elements for the numerical simulation of the problem. The equations of motion of the fluid are expressed as full N-S equation. A new type of bio-inspired boundary condition has been proposed. A prototype of the jellyfish setup has been developed for the experimental validation of the simulation results. The solution of the coupled system is accomplished by solving the two systems separately with the interaction effects using immersed boundary method. This study will be useful in accurate calculation of pressure distribution, maximum blocking stress, strain rate and actuator system for submerged autonomous vehicle. This study will also help in designing efficient propulsion and thruster mechanism for unmanned underwater vehicle. It is believed that the research presented in this paper advances the understanding of the dynamic behavior of bio-inspired UUV.

  16. Hands-on Science. How Do Sea Critters Make Their Moves?

    ERIC Educational Resources Information Center

    VanCleave, Janice

    1998-01-01

    Three science experiments teach elementary school students about marine-life locomotion. One teaches primary students how octopi and jellyfish move, using balloons and umbrellas. Another teaches K-6 students the up and down movement of fish in water, using condiment packets. A third teaches 4-6 students about the effect of fish swim bladders,…

  17. Marine & Other Invertebrates. Animal Life in Action[TM]. Schlessinger Science Library. [Videotape].

    ERIC Educational Resources Information Center

    2000

    This 23-minute videotape for grades 5-8, presents the myriad of animal life that exists on the planet. Students can view and perform experiments and investigations that help explain animal traits and habits. Invertebrate animals include a vast array of spineless creatures. In this video, students discover marine lifeforms such as jellyfish,…

  18. THE MORPHOLOGY OF STINGING CELLS IN THE MARINE INVERTEBRATE NUDIBRANCH, CRATENA PILATA

    EPA Science Inventory

    The association between the marine invertebrate nudibranch, Cratena pilata, and its food source has intrigued researchers for many years. These nudibranchs, or shell-less snails, obtain stinging cells by feeding on the jellyfish-like coelenterate, Tubularia sp. It is believed tha...

  19. Seasonal and vertical distributional patterns of siphonophores and medusae in the Chiloé Interior Sea, Chile

    NASA Astrophysics Data System (ADS)

    Palma, Sergio; Silva, Nelson; Cristina Retamal, María; Castro, Leonardo

    2011-03-01

    The horizontal and vertical distribution of jellyfish was assessed in the Chiloé Inland sea, in the northern area of the Chilean Patagonia. A total of 41 species of cnidarians (8 siphonophores, 31 hydromedusae, 2 scyphomedusae) were collected. Eleven jellyfish species were recorded for the first time in the area. Species richness was higher in spring than in winter (37 vs. 25 species, respectively). Species such as Muggiaea atlantica, Solmundella bitentaculata, and Clytia simplex were extremely abundant in spring. The total abundance (408,157 ind 1000 m -3) was 18 times higher in spring than in winter (22,406 ind 1000 m -3). The horizontal distribution of the most abundant species (four in winter, five in spring) showed decreasing abundances in the north-south direction in winter and spring. Peak abundances occurred in the northern microbasins (Reloncaví Fjord, Reloncaví and Ancud gulfs), where the water column stability, phytoplankton and zooplankton abundance were higher, compared with the southern microbasins (Corcovado Gulf, Boca del Guafo). During the spring higher jellyfish abundance season, the vertical distribution of the dominant species (except M. atlantica) showed peak values at mid-depth (30-50 m) and in the deepest sampled layer (50-200 m). This vertical distribution pattern reduced seaward transport in the shallowest layer through estuarine circulation and also limited mortality by predation in the more illuminated shallow layers. Thus, jellyfish were able to remain in the interior waters during the season of maximum biological production.

  20. Green fluorescent protein glows gold.

    PubMed

    Miyawaki, Atsushi

    2008-12-12

    The awarding of this year's Nobel Prize in Chemistry to Osamu Shimomura, Martin Chalfie, and Roger Tsien for their discovery and development of green fluorescent protein earns this humble jellyfish protein a place of honor in the biology research hall of fame. PMID:19070562

  1. Monitoring transgenic plants using in vivo markers

    SciTech Connect

    Stewart, C.N. Jr.

    1996-06-01

    The gene coding for green fluorecent protein (GFP), isolated and cloned from the jellyfish Aequorea victoria, is an ideal transgene for the monitoring of any plant species. It has the ability to fluoresce without added substrate, enzyme, or cofactor; it does not introduce morphological or sexual aberrations when expressed. 7 refs., 1 fig.

  2. 76 FR 17107 - Fisheries of the Exclusive Economic Zone Off Alaska; Application for an Exempted Fishing Permit

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-28

    ... the intercooperative agreement for salmon bycatch reduction is at 72 FR 61070 (October 29, 2007). Information regarding Amendment 91 for Bering Sea Chinook salmon bycatch management is at 75 FR 53026, August... be Pacific cod, skates, flatfish, halibut, and jellyfish. The amount of groundfish harvest under...

  3. Effects of a flexible margin on Robojelly vortex structures

    NASA Astrophysics Data System (ADS)

    Villanueva, Alex; Stewart, Kelley; Vlachos, Pavlos; Priya, Shashank

    2011-11-01

    An Unmanned Underwater Vehicle (UUV) inspired by jellyfish morphology and propulsion mechanism, termed ``Robojelly,'' was used to analyze the effects of the flexible margin on jellyfish propulsion. The natural animal has a bell section which deforms at a different phase then the rest of the bell. This lagging section, referred to as flexible margin or flap, is delimited by the bell margin and an inflexion point. The flap was replicated on the robotic vehicle by a flexible passive material to conduct a systematic parametric study. In a preliminary experiment, Robojelly was tested without a flap and with a flap. This revealed a thrust increase over an order of magnitude. We hypothesize that the length of this passive flap affects the vortex ring circulation strength of the jellyfish which can lead to higher efficiency and thrust. Velocity field measurements were performed using planar Time Resolved Digital Particle Image Velocimetry (TRDPIV) to analyze the change in vortex structures as a function of flap length. The robot input parameters stayed constant over the different configurations tested thus maintaining a near constant power consumption. Results clearly demonstrate that the flap plays an important role in the propulsion mechanism of Robojelly and provides an anatomical understanding of natural jellyfish.

  4. Handle with Care! Mid-Atlantic Marine Animals That Demand Your Respect. Educational Series No. 26. Third Printing.

    ERIC Educational Resources Information Center

    Lucy, Jon

    Generally speaking, marine organisms found along middle Atlantic shores are not considered threatening to people. However, some of these animals can cause problems, either upon simple contact with the skin, as in the case of some jellyfish, or through careless handling. In addition, larger inhabitants of coastal waters (such as sharks) must always…

  5. Seascapes: Glimpses of Our Water World.

    ERIC Educational Resources Information Center

    Hardin, Jan

    Presented is a collection of newspaper articles prepared by the Delaware Sea Grant Marine Advisory Service during the summer of 1978. Subjects addressed are bioluminescence, beachcomber finds, gulls, beach erosion, marine research activities, barnacles, sand, seaweed, jellyfish, shore restaurants, diving mammals, and tides. (Author/BW)

  6. A Sea Creature Treasury. Project CAPE Teaching Module K-2b.

    ERIC Educational Resources Information Center

    Gray, Carmen P.; Forrest, Diane W.

    Fifteen interdisciplinary lessons on marine invertebrates (mollusks, echinoderms, and jellyfish) are provided in this unit designed for students in kindergarten and in grades 1 and 2. Each lesson includes lesson concept, competency goals, objectives, materials needed, background information, teacher preparation, and activities suitable for use in…

  7. Reconstructing Source-Sink Dynamics in a Population with a Pelagic Dispersal Phase

    PubMed Central

    Chen, Kun; Ciannelli, Lorenzo; Decker, Mary Beth; Ladd, Carol; Cheng, Wei; Zhou, Ziqian; Chan, Kung-Sik

    2014-01-01

    For many organisms, the reconstruction of source-sink dynamics is hampered by limited knowledge of the spatial assemblage of either the source or sink components or lack of information on the strength of the linkage for any source-sink pair. In the case of marine species with a pelagic dispersal phase, these problems may be mitigated through the use of particle drift simulations based on an ocean circulation model. However, when simulated particle trajectories do not intersect sampling sites, the corroboration of model drift simulations with field data is hampered. Here, we apply a new statistical approach for reconstructing source-sink dynamics that overcomes the aforementioned problems. Our research is motivated by the need for understanding observed changes in jellyfish distributions in the eastern Bering Sea since 1990. By contrasting the source-sink dynamics reconstructed with data from the pre-1990 period with that from the post-1990 period, it appears that changes in jellyfish distribution resulted from the combined effects of higher jellyfish productivity and longer dispersal of jellyfish resulting from a shift in the ocean circulation starting in 1991. A sensitivity analysis suggests that the source-sink reconstruction is robust to typical systematic and random errors in the ocean circulation model driving the particle drift simulations. The jellyfish analysis illustrates that new insights can be gained by studying structural changes in source-sink dynamics. The proposed approach is applicable for the spatial source-sink reconstruction of other species and even abiotic processes, such as sediment transport. PMID:24835251

  8. Australian orchids and the doctors they commemorate.

    PubMed

    Pearn, John H

    2013-01-21

    Botanical taxonomy is a repository of medical biographical information. Such botanical memorials include the names of some indigenous orchids of Australia. By searching reference texts and journals relating to Australian botany and Australian orchidology, as well as Australian and international medical and botanical biographical texts, I identified 30 orchids indigenous to Australia whose names commemorate doctors and other medical professionals. Of these, 24 have names that commemorate a total of 16 doctors who worked in Australia. The doctors and orchids I identified include: doctor-soldiers Richard Sanders Rogers (1862-1942), after whom the Rogers' Greenhood (Pterostylis rogersii) is named, and Robert Brown (1773-1858), after whom the Purple Enamel Orchid (Elythranthera brunonis) is named; navy surgeon Archibald Menzies (1754-1842), after whom the Hare Orchid (Leptoceras menziesii) is named; radiologist Hugo Flecker (1884-1957) after whom the Slender Sphinx Orchid (Cestichis fleckeri) is named; and general medical practitioner Hereward Leighton Kesteven (1881-1964), after whom the Kesteven's Orchid (Dendrobium kestevenii) is named. Biographic references in scientific names of plants comprise a select but important library of Australian medical history. Such botanical taxonomy commemorates, in an enduring manner, clinicians who have contributed to biology outside clinical practice. PMID:23330773

  9. SHOCKING TAILS IN THE MAJOR MERGER ABELL 2744

    SciTech Connect

    Owers, Matt S.; Couch, Warrick J.; Nulsen, Paul E. J.; Randall, Scott W.

    2012-05-01

    We identify four rare 'jellyfish' galaxies in Hubble Space Telescope imagery of the major merger cluster Abell 2744. These galaxies harbor trails of star-forming knots and filaments which have formed in situ in gas tails stripped from the parent galaxies, indicating they are in the process of being transformed by the environment. Further evidence for rapid transformation in these galaxies comes from their optical spectra, which reveal starburst, poststarburst, and active galactic nucleus features. Most intriguingly, three of the jellyfish galaxies lie near intracluster medium features associated with a merging 'Bullet-like' subcluster and its shock front detected in Chandra X-ray images. We suggest that the high-pressure merger environment may be responsible for the star formation in the gaseous tails. This provides observational evidence for the rapid transformation of galaxies during the violent core passage phase of a major cluster merger.

  10. Lagrangian analysis of fluid transport in empirical vortex ring flows

    NASA Astrophysics Data System (ADS)

    Shadden, Shawn C.; Dabiri, John O.; Marsden, Jerrold E.

    2006-04-01

    In this paper we apply dynamical systems analyses and computational tools to fluid transport in empirically measured vortex ring flows. Measurements of quasisteadily propagating vortex rings generated by a mechanical piston-cylinder apparatus reveal lobe dynamics during entrainment and detrainment that are consistent with previous theoretical and numerical studies. In addition, the vortex ring wake of a free-swimming Aurelia aurita jellyfish is measured and analyzed in the framework of dynamical systems to elucidate similar lobe dynamics in a naturally occurring biological flow. For the mechanically generated rings, a comparison of the net entrainment rate based on the present methods with a previous Eulerian analysis shows good correspondence. However, the current Lagrangian framework is more effective than previous analyses in capturing the transport geometry, especially when the flow becomes more unsteady, as in the case of the free-swimming jellyfish. Extensions of these results to more complex flow geometries is suggested.

  11. A fluid mechanical model for mixing in a plankton predator-prey system

    NASA Astrophysics Data System (ADS)

    Peng, J.; Dabiri, J. O.

    2009-04-01

    A Lagrangian method is developed to study mixing of small particles in open flows. Particle Lagrangian Coherent Structures (pLCS) are identified as transport barriers in the dynamical systems of particles. We apply this method to a planktonic predator-prey system in which moon jellyfish Aurelia aurita uses its body motion to generate fluid currents which carry their prey to the vicinity of their capture appendages. With the flow generated by the jellyfish experimentally measured and the dynamics of prey particles in the flow described by a modified Maxey-Riley equation, we use pLCS to identify the capture region in which prey can be captured. The properties of the capture region enable analysis of the effects of several physiological and mechanical parameters on the predator-prey interaction, such as prey size, escape force, predator perception, etc. The method provides a new methodology to study dynamics and mixing of small organisms in general.

  12. Portuguese Man-of-War (Physalia physalis) in the Mediterranean: A permanent invasion or a casual appearance?

    PubMed

    Prieto, L; Macías, D; Peliz, A; Ruiz, J

    2015-01-01

    In 2010, the Mediterranean basin experienced Portuguese Man-of-War (Physalia physalis) swarms that had dramatic consequences, including the region's first recorded human fatality attributed to a jellyfish sting. Despite the impact of jellyfish on coastal economic activity and the importance of the tourism industry for the Mediterranean region (accounting for 15% of global tourism), no scientific consensus has been achieved regarding the causes of this episode. Here, we analyse the meteorological and oceanographic conditions of the North-East Atlantic Ocean during the months previous to the appearance of P. physalis in the Mediterranean. We simulate the probable drift of Atlantic populations into the Mediterranean basin with a numerical model and compare model results with available observations. We conclude that the summer 2010 P. Physalis swarm was the result of an unusual combination of meteorological and oceanographic conditions during the previous winter and not a permanent invasion favoured by climatic changes. PMID:26108978

  13. Shocking Tails in the Major Merger Abell 2744

    NASA Astrophysics Data System (ADS)

    Owers, Matt S.; Couch, Warrick J.; Nulsen, Paul E. J.; Randall, Scott W.

    2012-05-01

    We identify four rare "jellyfish" galaxies in Hubble Space Telescope imagery of the major merger cluster Abell 2744. These galaxies harbor trails of star-forming knots and filaments which have formed in situ in gas tails stripped from the parent galaxies, indicating they are in the process of being transformed by the environment. Further evidence for rapid transformation in these galaxies comes from their optical spectra, which reveal starburst, poststarburst, and active galactic nucleus features. Most intriguingly, three of the jellyfish galaxies lie near intracluster medium features associated with a merging "Bullet-like" subcluster and its shock front detected in Chandra X-ray images. We suggest that the high-pressure merger environment may be responsible for the star formation in the gaseous tails. This provides observational evidence for the rapid transformation of galaxies during the violent core passage phase of a major cluster merger.

  14. The Wide-Field Nearby Galaxy-Cluster Survey (WINGS) and Its Extension OMEGAWINGS

    NASA Astrophysics Data System (ADS)

    Poggianti, B. M.; Fasano, G.; Bettoni, D.; Cava, A.; Couch, W.; D'Onofrio, M.; Dressler, A.; Fritz, J.; Kjaergaard, P.; Gullieuszik, M.; Moles, M.; Moretti, A.; Omizzolo, A.; Paccagnella, A.; Varela, J.; Vulcani, B.

    WINGS is a wide-field multi-wavelength survey of 76 X-ray selected clusters at low redshift. The WINGS database has been used for a variety of cluster and cluster galaxy studies, investigating galaxy star formation, morphologies, structure, stellar mass functions and other properties. We present the recent wider-field extension of WINGS, OMEGAWINGS, conducted with OmegaCAM@VST and AAOmega@AAT. We show two of our latest results regarding jellyfish galaxies and galaxy sizes. OMEGAWINGS has allowed the first systematic search of galaxies with signs of ongoing ram pressure stripping (jellyfishes), yielding a catalog of ˜ 240 galaxies in 41 clusters. We discuss the first results obtained from this sample and the prospects for integral field data. Finally, we summarize our results regarding the discovery of compact massive galaxies at low redshift, their properties, dependence on environment and the implications for the evolution of galaxy sizes from high- to low-z.

  15. Trace element accumulation in Cassiopea sp. (Scyphozoa) from urban marine environments in Australia.

    PubMed

    Templeman, Michelle A; Kingsford, Michael J

    2010-03-01

    Jellyfishes are robust, short-lived animals, tolerant to a wide range of environmental conditions and pollutants. The benthic jellyfish, Cassiopea sp. was collected from five locations along the north and eastern coast of Australia and analysed for trace elements to determine if this species has potential as a marine biomonitor. Both the oral arm and bell tissues readily accumulated aluminium, arsenic, barium, cadmium, chromium, copper, iron, manganese and zinc above ambient seawater levels. In contrast, lithium appeared to be actively regulated within the tissues while calcium, magnesium and strontium reflected the ambient environment. The multi-element signatures showed spatial variation, reflecting the geographical separations between locations, with locations closer together showing more similar elemental patterns. The combination of bioaccumulative capacity, life history traits and biophysical aspects indicate that this species has high potential as a biomonitor in coastal marine systems. PMID:19747724

  16. Portuguese Man-of-War (Physalia physalis) in the Mediterranean: A permanent invasion or a casual appearance?

    NASA Astrophysics Data System (ADS)

    Prieto, L.; Macías, D.; Peliz, A.; Ruiz, J.

    2015-06-01

    In 2010, the Mediterranean basin experienced Portuguese Man-of-War (Physalia physalis) swarms that had dramatic consequences, including the region’s first recorded human fatality attributed to a jellyfish sting. Despite the impact of jellyfish on coastal economic activity and the importance of the tourism industry for the Mediterranean region (accounting for 15% of global tourism), no scientific consensus has been achieved regarding the causes of this episode. Here, we analyse the meteorological and oceanographic conditions of the North-East Atlantic Ocean during the months previous to the appearance of P. physalis in the Mediterranean. We simulate the probable drift of Atlantic populations into the Mediterranean basin with a numerical model and compare model results with available observations. We conclude that the summer 2010 P. Physalis swarm was the result of an unusual combination of meteorological and oceanographic conditions during the previous winter and not a permanent invasion favoured by climatic changes.

  17. Portuguese Man-of-War (Physalia physalis) in the Mediterranean: A permanent invasion or a casual appearance?

    PubMed Central

    Prieto, L.; Macías, D.; Peliz, A.; Ruiz, J.

    2015-01-01

    In 2010, the Mediterranean basin experienced Portuguese Man-of-War (Physalia physalis) swarms that had dramatic consequences, including the region’s first recorded human fatality attributed to a jellyfish sting. Despite the impact of jellyfish on coastal economic activity and the importance of the tourism industry for the Mediterranean region (accounting for 15% of global tourism), no scientific consensus has been achieved regarding the causes of this episode. Here, we analyse the meteorological and oceanographic conditions of the North-East Atlantic Ocean during the months previous to the appearance of P. physalis in the Mediterranean. We simulate the probable drift of Atlantic populations into the Mediterranean basin with a numerical model and compare model results with available observations. We conclude that the summer 2010 P. Physalis swarm was the result of an unusual combination of meteorological and oceanographic conditions during the previous winter and not a permanent invasion favoured by climatic changes. PMID:26108978

  18. Aluminium in food and daily dietary intake assessment from 15 food groups in Zhejiang Province, China.

    PubMed

    Zhang, Hexiang; Tang, Jun; Huang, Lichun; Shen, Xianghong; Zhang, Ronghua; Chen, Jiang

    2016-06-01

    Aluminium was measured in 2580 samples of 15 food groups and dietary exposure was estimated. Samples were purchased and analysed during 2010 to 2014. High aluminium levels were found in jellyfish (mean 4862 mg/kg), laver (mean 455.2 mg/kg) and fried twisted cruller (mean 392.4 mg/kg). Dietary exposure to aluminium was estimated for Zhejiang residents. The average dietary exposure to aluminium via 15 food groups in Zhejiang Province was 1.15 mg/kg bw/week, which is below the provisional tolerable weekly intake of 2 mg/kg bw /week. Jellyfish is the main Al contributor, providing 37.6% of the daily intake via these 15 food groups. This study provided new information on aluminium levels and assessment of aluminium (Al) dietary exposure in Zhejiang Province of China. PMID:26727195

  19. Flexible Margin Kinematics and Vortex Formation of Aurelia aurita and Robojelly

    PubMed Central

    Villanueva, Alex; Vlachos, Pavlos; Priya, Shashank

    2014-01-01

    The development of a rowing jellyfish biomimetic robot termed as “Robojelly”, has led to the discovery of a passive flexible flap located between the flexion point and bell margin on the Aurelia aurita. A comparative analysis of biomimetic robots showed that the presence of a passive flexible flap results in a significant increase in the swimming performance. In this work we further investigate this concept by developing varying flap geometries and comparing their kinematics with A. aurita. It was shown that the animal flap kinematics can be replicated with high fidelity using a passive structure and a flap with curved and tapered geometry gave the most biomimetic performance. A method for identifying the flap location was established by utilizing the bell curvature and the variation of curvature as a function of time. Flaps of constant cross-section and varying lengths were incorporated on the Robojelly to conduct a systematic study of the starting vortex circulation. Circulation was quantified using velocity field measurements obtained from planar Time Resolved Digital Particle Image Velocimetry (TRDPIV). The starting vortex circulation was scaled using a varying orifice model and a pitching panel model. The varying orifice model which has been traditionally considered as the better representation of jellyfish propulsion did not appear to capture the scaling of the starting vortex. In contrast, the pitching panel representation appeared to better scale the governing flow physics and revealed a strong dependence on the flap kinematics and geometry. The results suggest that an alternative description should be considered for rowing jellyfish propulsion, using a pitching panel method instead of the traditional varying orifice model. Finally, the results show the importance of incorporating the entire bell geometry as a function of time in modeling rowing jellyfish propulsion. PMID:24905025

  20. Engineering Bioluminescent Proteins: Expanding their Analytical Potential

    PubMed Central

    Rowe, Laura; Dikici, Emre; Daunert, Sylvia

    2009-01-01

    Synopsis Bioluminescence has been observed in nature since the dawn of time, but now, scientists are harnessing it for analytical applications. Laura Rowe, Emre Dikici, and Sylvia Daunert of the University of Kentucky describe the origins of bioluminescent proteins and explore their uses in the modern chemistry laboratory. The cover features spectra of bioluminescent light superimposed on an image of jellyfish, which are a common source of bioluminescent proteins. Images courtesy of Emre Dikici and Shutterstock. PMID:19725502

  1. Biological Imaging Capability in the ABRS Facility on ISS

    NASA Technical Reports Server (NTRS)

    Cox, David R.; Murdoch, T.; Regan, M. F.; Meshlberger, R. J.; Mortenson, T. E.; Albino, S. A.; Paul, A. L.; Ferl, R. J.

    2010-01-01

    This slide presentation reviews the Advanced Biological Research System (ABRS) on the International Space Station (ISS) and its biological imaging capability. The ABRS is an environmental control chamber. It has two indpendently controlled Experiment Research Chambers (ERCs) with temperature, relative humidity and carbon dioxide controls. ABRS is a third generation plant growth system. Several experiments are reviewed, with particular interest in the use of Green Fluorescent Protein (GFP) a non-destructive plant stress reporting mechanism, naturally found in jellyfish.

  2. Biota of a Pennsylvanian muddy coast: habitat within the Mazonian delta complex, northeast Illinois

    SciTech Connect

    Baird, G.C.

    1985-03-01

    The Mazon Creek biota (Westphalian D) is composed of plants and animals from terrestrial fresh water and marginal marine habitats. Fossil animals, including jellyfish, worms, crustaceans, holothurians, insects, chordates, and problematica occur in sideritic concretions on spoilpiles of more than 100 abandoned coal mines in a five county region (Mazon Creek area) of northeast Illinois. These fossils record rapid burial and early diagenesis in a muddy, delta-influenced coastal setting submerged during marine transgression.

  3. 5S rRNA sequences from four marine invertebrates and implications for base pairing models of metazoan sequences.

    PubMed

    Walker, W F; Doolittle, W F

    1983-08-11

    The nucleotide sequences of 5S rRNAs from the starfish Asterias vulgaris, the squid Illex illecebrosus, the sipunculid Phascolopsis gouldii and the jellyfish Aurelia aurita were determined. The sequence from Asterias lends support for one of two previous base pairing models for helix E in metazoan sequences. The Aurelia sequence differs by five nucleotides from that previously reported and does not violate the consensus secondary structure model for eukaryotic 5S rRNA. PMID:6136024

  4. Flexible margin kinematics and vortex formation of Aurelia aurita and Robojelly.

    PubMed

    Villanueva, Alex; Vlachos, Pavlos; Priya, Shashank

    2014-01-01

    The development of a rowing jellyfish biomimetic robot termed as "Robojelly", has led to the discovery of a passive flexible flap located between the flexion point and bell margin on the Aurelia aurita. A comparative analysis of biomimetic robots showed that the presence of a passive flexible flap results in a significant increase in the swimming performance. In this work we further investigate this concept by developing varying flap geometries and comparing their kinematics with A. aurita. It was shown that the animal flap kinematics can be replicated with high fidelity using a passive structure and a flap with curved and tapered geometry gave the most biomimetic performance. A method for identifying the flap location was established by utilizing the bell curvature and the variation of curvature as a function of time. Flaps of constant cross-section and varying lengths were incorporated on the Robojelly to conduct a systematic study of the starting vortex circulation. Circulation was quantified using velocity field measurements obtained from planar Time Resolved Digital Particle Image Velocimetry (TRDPIV). The starting vortex circulation was scaled using a varying orifice model and a pitching panel model. The varying orifice model which has been traditionally considered as the better representation of jellyfish propulsion did not appear to capture the scaling of the starting vortex. In contrast, the pitching panel representation appeared to better scale the governing flow physics and revealed a strong dependence on the flap kinematics and geometry. The results suggest that an alternative description should be considered for rowing jellyfish propulsion, using a pitching panel method instead of the traditional varying orifice model. Finally, the results show the importance of incorporating the entire bell geometry as a function of time in modeling rowing jellyfish propulsion. PMID:24905025

  5. Accumulation of nanoparticles in “jellyfish” mucus: a bio-inspired route to decontamination of nano-waste

    PubMed Central

    Patwa, Amit; Thiéry, Alain; Lombard, Fabien; Lilley, Martin K.S.; Boisset, Claire; Bramard, Jean-François; Bottero, Jean-Yves; Barthélémy, Philippe

    2015-01-01

    The economic and societal impacts of nano-materials are enormous. However, releasing such materials in the environment could be detrimental to human health and the ecological biosphere. Here we demonstrate that gold and quantum dots nanoparticles bio-accumulate into mucus materials coming from natural species such as jellyfish. One strategy that emerges from this finding would be to take advantage of these trapping properties to remove nanoparticles from contaminated water. PMID:26096459

  6. Accumulation of nanoparticles in “jellyfish” mucus: a bio-inspired route to decontamination of nano-waste

    NASA Astrophysics Data System (ADS)

    Patwa, Amit; Thiéry, Alain; Lombard, Fabien; Lilley, Martin K. S.; Boisset, Claire; Bramard, Jean-François; Bottero, Jean-Yves; Barthélémy, Philippe

    2015-06-01

    The economic and societal impacts of nano-materials are enormous. However, releasing such materials in the environment could be detrimental to human health and the ecological biosphere. Here we demonstrate that gold and quantum dots nanoparticles bio-accumulate into mucus materials coming from natural species such as jellyfish. One strategy that emerges from this finding would be to take advantage of these trapping properties to remove nanoparticles from contaminated water.

  7. Ambient temperature catalyst-free light-induced preparation of macrocyclic aliphatic polyesters.

    PubMed

    Josse, Thomas; Altintas, Ozcan; Oehlenschlaeger, Kim K; Dubois, Philippe; Gerbaux, Pascal; Coulembier, Olivier; Barner-Kowollik, Christopher

    2014-02-25

    The light induced, catalyst-free ambient temperature preparation of macrocyclic aliphatic polyesters is pioneered. Based on the photo-induced Diels-Alder reaction of orthoquinodimethane and acrylate moieties, cyclic polyesters of high purity are readily synthesized. Considering the high tolerance to functional groups and the orthogonality of the ligation, the reported protocol can be easily transferred to a large range of polymers, complex topologies (tadpole, sun-shaped, jellyfish, etc.) and applications. PMID:24413149

  8. Resource requirements of the Pacific leatherback turtle population.

    PubMed

    Jones, T Todd; Bostrom, Brian L; Hastings, Mervin D; Van Houtan, Kyle S; Pauly, Daniel; Jones, David R

    2012-01-01

    The Pacific population of leatherback sea turtles (Dermochelys coriacea) has drastically declined in the last 25 years. This decline has been linked to incidental capture by fisheries, egg and meat harvesting, and recently, to climate variability and resource limitation. Here we couple growth rates with feeding experiments and food intake functions to estimate daily energy requirements of leatherbacks throughout their development. We then estimate mortality rates from available data, enabling us to raise food intake (energy requirements) of the individual to the population level. We place energy requirements in context of available resources (i.e., gelatinous zooplankton abundance). Estimated consumption rates suggest that a single leatherback will eat upward of 1000 metric tonnes (t) of jellyfish in its lifetime (range 924-1112) with the Pacific population consuming 2.1×10(6) t of jellyfish annually (range 1.0-3.7×10(6)) equivalent to 4.2×10(8) megajoules (MJ) (range 2.0-7.4×10(8)). Model estimates suggest 2-7 yr-old juveniles comprise the majority of the Pacific leatherback population biomass and account for most of the jellyfish consumption (1.1×10(6) t of jellyfish or 2.2×10(8) MJ per year). Leatherbacks are large gelatinous zooplanktivores with consumption to biomass ratios of 96 (up to 192 if feeding strictly on low energy density Cnidarians); they, therefore, have a large capacity to impact gelatinous zooplankton landscapes. Understanding the leatherback's needs for gelatinous zooplankton, versus the availability of these resources, can help us better assess population trends and the influence of climate induced resource limitations to reproductive output. PMID:23071518

  9. Resource Requirements of the Pacific Leatherback Turtle Population

    PubMed Central

    Jones, T. Todd; Bostrom, Brian L.; Hastings, Mervin D.; Van Houtan, Kyle S.; Pauly, Daniel; Jones, David R.

    2012-01-01

    The Pacific population of leatherback sea turtles (Dermochelys coriacea) has drastically declined in the last 25 years. This decline has been linked to incidental capture by fisheries, egg and meat harvesting, and recently, to climate variability and resource limitation. Here we couple growth rates with feeding experiments and food intake functions to estimate daily energy requirements of leatherbacks throughout their development. We then estimate mortality rates from available data, enabling us to raise food intake (energy requirements) of the individual to the population level. We place energy requirements in context of available resources (i.e., gelatinous zooplankton abundance). Estimated consumption rates suggest that a single leatherback will eat upward of 1000 metric tonnes (t) of jellyfish in its lifetime (range 924–1112) with the Pacific population consuming 2.1×106 t of jellyfish annually (range 1.0–3.7×106) equivalent to 4.2×108 megajoules (MJ) (range 2.0–7.4×108). Model estimates suggest 2–7 yr-old juveniles comprise the majority of the Pacific leatherback population biomass and account for most of the jellyfish consumption (1.1×106 t of jellyfish or 2.2×108 MJ per year). Leatherbacks are large gelatinous zooplanktivores with consumption to biomass ratios of 96 (up to 192 if feeding strictly on low energy density Cnidarians); they, therefore, have a large capacity to impact gelatinous zooplankton landscapes. Understanding the leatherback's needs for gelatinous zooplankton, versus the availability of these resources, can help us better assess population trends and the influence of climate induced resource limitations to reproductive output. PMID:23071518

  10. Ontogeny of antipredator performance in hatchery-reared Japanese anchovy Engraulis japonicus larvae exposed to visual or tactile predators in relation to turbidity.

    PubMed

    Ohata, R; Masuda, R; Yamashita, Y

    2011-12-01

    Laboratory experiments revealed distinct effects of turbidity on the survival of Japanese anchovy Engraulis japonicus larvae when exposed to either visual (jack mackerel Trachurus japonicus) or tactile (moon jellyfish Aurelia aurita) predators. The experiments were conducted in 30 l tanks with three levels of turbidity obtained by dissolving 0, 50 or 300 mg l(-1) of kaolin. Predators were introduced to experimental tanks followed by larvae of E. japonicus ranging from 5 to 25 mm standard lengths (L(s) ). When exposed to T. japonicus, the mean survival rate of larvae was significantly higher in 300 mg l(-1) treatments compared to the other turbidity levels. When exposed to A. aurita, however, there was no difference in the survival rates among different turbidity treatments. The survival rates when exposed to either predator improved with larval growth. The logistic survivorship models for E. japonicus larvae when exposed to A. aurita had an inflection point at c. 12 mm L(s) , suggesting that their size refuge from A. aurita is close to this value. Comparison to a previous study suggests a high vulnerability of shirasu (long and transparent) fish larvae to jellyfish predation under turbidity. This study indicates that anthropogenic increases of turbidity in coastal waters may increase the relative effect of jellyfish predation on fish larvae. PMID:22141901

  11. Insight into the Molecular and Functional Diversity of Cnidarian Neuropeptides

    PubMed Central

    Takahashi, Toshio; Takeda, Noriyo

    2015-01-01

    Cnidarians are the most primitive animals to possess a nervous system. This phylum is composed of the classes Scyphozoa (jellyfish), Cubozoa (box jellyfish), and Hydrozoa (e.g., Hydra, Hydractinia), which make up the subphylum Medusozoa, as well as the class Anthozoa (sea anemones and corals). Neuropeptides have an early evolutionary origin and are already abundant in cnidarians. For example, from the cnidarian Hydra, a key model system for studying the peptides involved in developmental and physiological processes, we identified a wide variety of novel neuropeptides from Hydra magnipapillata (the Hydra Peptide Project). Most of these peptides act directly on muscle cells and induce contraction and relaxation. Some peptides are involved in cell differentiation and morphogenesis. In this review, we describe FMRFamide-like peptides (FLPs), GLWamide-family peptides, and the neuropeptide Hym-355; FPQSFLPRGamide. Several hundred FLPs have been isolated from invertebrate animals such as cnidarians. GLWamide-family peptides function as signaling molecules in muscle contraction, metamorphosis, and settlement in cnidarians. Hym-355; FPQSFLPRGamide enhances neuronal differentiation in Hydra. Recently, GLWamide-family peptides and Hym-355; FPQSFLPRGamide were shown to trigger oocyte maturation and subsequent spawning in the hydrozoan jellyfish Cytaeis uchidae. These findings suggest the importance of these neuropeptides in both developmental and physiological processes. PMID:25625515

  12. Offshore dispersion of ephyrae and medusae of Aurelia aurita s.l. (Cnidaria: Scyphozoa) from port enclosures: Physical and biological factors

    NASA Astrophysics Data System (ADS)

    Makabe, Ryosuke; Takeoka, Hidetaka; Uye, Shin-ichi

    2015-12-01

    Recurrent outbreaks of the common jellyfish Aurelia aurita s.l. have been increasingly significant, particularly in human perturbed coastal waters, where numerous artificial constructions increase suitable habitat for polyp populations. We examined the spatiotemporal dispersion process in 6 ports of ephyrae of A. aurita after release from strobilating polyps, to offshore waters of northern Harima Nada (eutrophic eastern Inland Sea of Japan) from January to May 2010. Almost exclusive occurrence of the ephyra stage in the ports demonstrated that their seeding polyps reside in the port enclosures, and liberated ephyrae are rapidly exported offshore by tidal water exchange. Post-ephyra stages occurred primarily outside the ports, and their age increased gradually offshore, ca. up to 9 km off the ports, and the pattern of age increase could be simulated by a simple diffusion model. However, there was an abrupt decline in A. aurita density beyond ca. 3 km off the shore, where jellyfish-eating Chrysaora pacifica medusae were prevalent. We conclude that physical forces are primarily responsible for offshore dispersion of A. aurita, and a biological factor, i.e. predation by C. pacifica, jointly affects the distribution pattern of A. aurita.

  13. Comparative biology of cAMP-induced germinal vesicle breakdown in marine invertebrate oocytes.

    PubMed

    Deguchi, Ryusaku; Takeda, Noriyo; Stricker, Stephen A

    2011-01-01

    During maturation, oocytes must undergo a process of nuclear disassembly, or "germinal vesicle breakdown" (GVBD), that is regulated by signaling pathways involving cyclic AMP (cAMP). In vertebrate and starfish oocytes, cAMP elevation typically prevents GVBD. Alternatively, increased concentrations of intra-oocytic cAMP trigger, rather than inhibit, GVBD in several groups of marine invertebrates. To integrate what is known about the stimulation of GVBD by intra-oocytic cAMP, this article reviews published data for ascidian, bivalve, brittle star, jellyfish, and nemertean oocytes. The bulk of the review concentrates on the three most intensively analyzed groups known to display cAMP-induced GVBD-nemerteans, ascidians, and jellyfish. In addition, this synopsis also presents some previously unpublished findings regarding the stimulatory effects of intra-oocytic cAMP on GVBD in jellyfish and the annelid worm Pseudopotamilla occelata. Finally, factors that may account for the currently known distribution of cAMP-induced GVBD across animal groups are discussed. PMID:21774023

  14. Bio-inspired unmanned undersea vehicle

    NASA Astrophysics Data System (ADS)

    Smith, Colin F.; Priya, Shashank

    2010-04-01

    Biological systems in ocean environment provide all the desired features required for design of unmanned undersea vehicles. We noticed the uniqueness and simplicity in the design of rowing medusa and have successfully demonstrated working prototypes of Aurelia Aurita. In this study, we demonstrate the effect of bell joints in reducing the contraction force required for deformation. The study is based on observations made for the sub-umbrella features of jellyfish. Artificial jellyfish unmanned undersea vehicle (UUV) was fabricated consisting of silicone as the matrix material and shape memory alloy (SMA) as the actuation material. UUV was characterized for its performance and tailored to achieve vertical motion. SMAs were selected for actuation material because they are simple current-driven device providing large strain and blocking force. However, electrical power requirements were found to be quite high in the underwater conditions. It was identified that by including "joints" in the structural material forming the bell, the overall power requirement can be reduced as it lowers the resistance to compression. An analytical model was developed that correlates the deformation achieved with the morphology of the joints. Experiments were conducted to characterize the effect of both joint shapes and structural materials on the motion. Results are compared with that of natural medusa gastrodermal lamella and analyzed using the theoretical model. By including the features inherently present in natural jellyfish, the required compression force was found to be decreased.

  15. Role of chemical and visual cues in food recognition by leatherback posthatchlings (Dermochelys coriacea L).

    PubMed

    Constantino, Maricela A; Salmon, Michael

    2003-01-01

    We raised leatherback posthatchlings in the laboratory for up to 7 weeks to study the role of visual and chemical cues in food recognition and food-seeking behavior. Turtles were reared on a formulated (artificial gelatinous) diet and had no contact with test materials until experiments began. Subjects were presented with visual cues (a plastic jellyfish; white plastic shapes [circle, square, diamond] similar in surface area to the plastic model), chemical cues (homogenates of lion's mane jellyfish, Cyanea capillata; moon jellyfish, Aurelia aurita; and a ctenophore, Ocyropsis sp., introduced through a water filter outflow), and visual and chemical cues presented simultaneously. Visual stimuli evoked an increase in swimming activity, biting, diving, and orientation toward the object. Chemical cues elicited an increase in biting, and orientation into water currents (rheotaxis). When chemical and visual stimuli were combined, turtles ignored currents and oriented toward the visual stimuli. We conclude that both cues are used to search for, and locate, food but that visual cues may be of primary importance. We hypothesize that under natural conditions turtles locate food visually, then, as a consequence of feeding, associate chemical with visual cues. Chemical cues then may function alone as a feeding attractant. PMID:16351903

  16. Numerical study of the seasonal variability of Aurelia aurita ephyra abundance: Application to the JiaoZhou Bay, China

    NASA Astrophysics Data System (ADS)

    Hu, Z.; Wang, N.; Li, C.; Sun, S.

    2013-12-01

    The outbreaks of the inshore scyphozoan Aurelia aurita have been increasingly reported in the coastal waters of China in recent years, with detrimental impacts on local ecosystems and economies. The strobilation process is an important part of the A. aurita life cycle because it can increase the jellyfish population size by producing new jellyfish (ephyrae). Hence it is essential to investigate the strobilation dynamics in order to better understand and possibly predict jellyfish outbreaks. In this work, we present a model that provides a realistic simulation of the combined effects of temperature and food supply on the ephyra liberation dynamics. The parameterization of the model is based on the laboratory and field experiments and the literature. The model results show that temperature has a parabolic-like effect on liberated ephyra numbers. The numbers of liberated ephyra increase with temperature before reaching a peak and then decays. No ephyrae liberation occurs in very low or very high temperautres, despite the food level is high or not. While liberation occurs, high food supply increases ephyra production. Application of the model to JiaoZhou Bay with in-situ measured temperature and zooplanton abundance produces results coherent with the seasonal in situ observations. In JiaoZhou Bay, the ephyrae of A. aurita usually appear in early April, and reaches their peak in abundance in June and the jellyfish outbreaks reported occurs in July-August. Experiments with the model show that there are two main periods of strobilation in JiaoZhou Bay. The first begins at early march and reaches its peak in May. The second occurs during October to early December with its peak in November. The first strobilation period is in a good agreement with in situ observations. No available data in JiaoZhou Bay could be used to validate the second one. Nevertheless, occurrence of A. aurita ephyrae was reported in late October in similar latitudes such as in Tokyo Bay. No jellyfish

  17. Reconstruction of the West Pacific ENSO precipitation anomaly using the compound-specific hydrogen isotopic record of marine lake sediments of Palau

    NASA Astrophysics Data System (ADS)

    Smittenberg, R. H.; Sachs, J. P.; Dawson, M. N.

    2004-12-01

    There is still much uncertainty whether the El Niño Southern Oscillation (ENSO) will become stronger or more frequent in a warming global climate. A principal reason for this uncertainty stems from a glaring lack of paleoclimate data in the equatorial Pacific, which hampers model validation. To partly resolve this data deficiency, sediments of three marine anoxic lakes were cored in Palau, an island group that lies in the heart of the West Pacific Warm Pool. The lakes contain seawater that seeps through fissures in the surrounding karst, and they are permanently stratified due to fresh water input provided by the year-round wet climate (map 1970-2000 = 3.7m). During ENSO events, however, the islands suffer from drought. The surface water hydrogen isotopic compositions in the lakes are sensitive to the relative proportions of D-depleted rainwater and D-enriched seawater, and are therefore sensitive to ENSO events. The lake surface water H/D values are recorded by algal and bacterial biomarkers that are preserved well in the highly organic and anoxic sediments, which accumulate relatively fast (mean 1 mm/yr). Ongoing down core measurement will eventually result in a precipitation proxy record of the islands. To obtain endmember D/H values, a comprehensive set of water samples from sea, lakes and rain water was obtained, as well as suspended particulate matter. Higher plant biomarker D/H values derived from the jungle vegetation surrounding the lakes may render supporting climatic proxy data, being influenced by evapotranspiration. Some lakes are inhabited by millions of jellyfish (Mastigias) that live in symbiosis with zooxanthellae. The jellyfish of one of the investigated lakes disappeared completely after the last large ENSO event in 1998 (returning in 2000-01), and a correlation is suggested. To reconstruct the history of jellyfish occurrence, jellyfish and sedimentary lipids were extracted and compared. In addition to a possible ENSO proxy record, this

  18. Selective toxin-lipid membrane interactions of natural, haemolytic Scyphozoan toxins analyzed by surface plasmon resonance.

    PubMed

    Helmholz, Heike

    2010-10-01

    A comparison of the molecular interaction of natural Scyphozoan lysins with their bioactivity in a haemolytic assay was performed by establishing an efficient, automatable and reproducible procedure for the measurement of protein-membrane interactions. The toxin-membrane interactions were analyzed utilising a chip-based technology with immobilized liposomes as artificial cell membranes. The technique was established with streptolysin O as a cholesterol-selective model toxin and its cholesterol-selectivity has been proven. The haemolytic potency of protein fractions derived from the venom of the jellyfish Aurelia aurita and Cyanea capillata was tested and EC50 values of 35.3mug/mL and 43.1mug/mL against sheep and 13.5mug/mL and 8.8mug/mL against rabbit erythrocytes were measured. Cell membrane binding as a first step in the haemolytic process was analyzed using the Biacore((R)) technology. Major cell membrane lipids (cholesterol, sphingomyelin and phosphatidylcholine) were immobilized as pure liposomes and in binary mixtures. A preference for cholesterol and sphingomyelin of both jellyfish species was demonstrated. The specificity of the method was proven with a non-haemolytic A. aurita protein fraction that did not express a lipid binding. Additionally, an inactivated C. capillata lysine with negligible haemolytic activity showed a remaining but reduced adsorption onto lipid layers. The binding level of the lytic venom fraction of these dominant boreal jellyfish species increased as a function of protein concentration. The binding strength was expressed in RU50 values ranging from 12.4mug/mL to 35.4mug/mL, which were in the same order of magnitude as the EC50 values in the haemolytic assay. PMID:20599534

  19. Effect of Sub-Lethal Exposure to Ultraviolet Radiation on the Escape Performance of Atlantic Cod Larvae (Gadus morhua)

    PubMed Central

    Fukunishi, Yuichi; Browman, Howard I.; Durif, Caroline M. F.; Bjelland, Reidun M.; Skiftesvik, Anne Berit

    2012-01-01

    The amount of ultraviolet (UV) radiation reaching the earth's surface has increased due to depletion of the ozone layer. Several studies have reported that UV radiation reduces survival of fish larvae. However, indirect and sub-lethal impacts of UV radiation on fish behavior have been given little consideration. We observed the escape performance of larval cod (24 dph, SL: 7.6±0.2 mm; 29 dph, SL: 8.2±0.3 mm) that had been exposed to sub-lethal levels of UV radiation vs. unexposed controls. Two predators were used (in separate experiments): two-spotted goby (Gobiusculus flavescens; a suction predator) and lion's mane jellyfish (Cyanea capillata; a “passive" ambush predator). Ten cod larvae were observed in the presence of a predator for 20 minutes using a digital video camera. Trials were replicated 4 times for goby and 5 times for jellyfish. Escape rate (total number of escapes/total number of attacks ×100), escape distance and the number of larvae remaining at the end of the experiment were measured. In the experiment with gobies, in the UV-treated larvae, both escape rate and escape distance (36%, 38±7.5 mm respectively) were significantly lower than those of control larvae (75%, 69±4.7 mm respectively). There was a significant difference in survival as well (UV: 35%, Control: 63%). No apparent escape response was observed, and survival rate was not significantly different, between treatments (UV: 66%, Control: 74%) in the experiment with jellyfish. We conclude that the effect and impact of exposure to sub-lethal levels of UV radiation on the escape performance of cod larvae depends on the type of predator. Our results also suggest that prediction of UV impacts on fish larvae based only on direct effects are underestimations. PMID:22536406

  20. Lagrangian coherent structures in low Reynolds number swimming.

    PubMed

    Wilson, Megan M; Peng, Jifeng; Dabiri, John O; Eldredge, Jeff D

    2009-05-20

    This work explores the utility of the finite-time Lyapunov exponent (FTLE) field for revealing flow structures in low Reynolds number biological locomotion. Previous studies of high Reynolds number unsteady flows have demonstrated that ridges of the FTLE field coincide with transport barriers within the flow, which are not shown by a more classical quantity such as vorticity. In low Reynolds number locomotion (O(1)-O(100)), in which viscous diffusion rapidly smears the vorticity in the wake, the FTLE field has the potential to add new insight to locomotion mechanics. The target of study is an articulated two-dimensional model for jellyfish-like locomotion, with swimming Reynolds number of order 1. The self-propulsion of the model is numerically simulated with a viscous vortex particle method, using kinematics adapted from previous experimental measurements on a live medusan swimmer. The roles of the ridges of the computed forward- and backward-time FTLE fields are clarified by tracking clusters of particles both backward and forward in time. It is shown that a series of ridges in front of the jellyfish in the forward-time FTLE field transport slender fingers of fluid toward the lip of the bell orifice, which are pulled once per contraction cycle into the wake of the jellyfish, where the fluid remains partitioned. A strong ridge in the backward-time FTLE field reveals a persistent barrier between fluid inside and outside the subumbrellar cavity. The system is also analyzed in a body-fixed frame subject to a steady free stream, and the FTLE field is used to highlight differences in these frames of reference. PMID:21825514

  1. Lagrangian coherent structures in low Reynolds number swimming

    NASA Astrophysics Data System (ADS)

    Wilson, Megan M.; Peng, Jifeng; Dabiri, John O.; Eldredge, Jeff D.

    2009-05-01

    This work explores the utility of the finite-time Lyapunov exponent (FTLE) field for revealing flow structures in low Reynolds number biological locomotion. Previous studies of high Reynolds number unsteady flows have demonstrated that ridges of the FTLE field coincide with transport barriers within the flow, which are not shown by a more classical quantity such as vorticity. In low Reynolds number locomotion (O(1)-O(100)), in which viscous diffusion rapidly smears the vorticity in the wake, the FTLE field has the potential to add new insight to locomotion mechanics. The target of study is an articulated two-dimensional model for jellyfish-like locomotion, with swimming Reynolds number of order 1. The self-propulsion of the model is numerically simulated with a viscous vortex particle method, using kinematics adapted from previous experimental measurements on a live medusan swimmer. The roles of the ridges of the computed forward- and backward-time FTLE fields are clarified by tracking clusters of particles both backward and forward in time. It is shown that a series of ridges in front of the jellyfish in the forward-time FTLE field transport slender fingers of fluid toward the lip of the bell orifice, which are pulled once per contraction cycle into the wake of the jellyfish, where the fluid remains partitioned. A strong ridge in the backward-time FTLE field reveals a persistent barrier between fluid inside and outside the subumbrellar cavity. The system is also analyzed in a body-fixed frame subject to a steady free stream, and the FTLE field is used to highlight differences in these frames of reference.

  2. The occurrence of Ophiocnemis marmorata (Echinodermata: Ophiuroidea) associated with the rhizostome medusa Rhopilema hispidum (Cnidaria: Scyphozoa)

    NASA Astrophysics Data System (ADS)

    Kanagaraj, Govindan; Kumar, Pithchai Sampath; Morandini, André C.

    2008-11-01

    The association of scyphomedusae with invertebrates has been long known in the literature; especially with hyperiids amphipods. The association of echinoderms with jellyfish is not common and rarely recorded. We reported the association of the ophiuroid Ophiocnemis marmorata with the rhizostome scyphomedusa Rhopilema hispidum collected in Vellar estuary (on the southeast coast of India). O. marmorata is supposed to be a filter feeding ophiuroid, quite common in soft bottom of shallow waters. The brittle stars possibly seek for food supply, shelter and protection through the association.

  3. A review of venomous animal bites and stings in pregnant patients.

    PubMed

    Langley, Ricky Lee

    2004-01-01

    This is a review of Medline and PubMed articles on venomous animal bites and stings during pregnancy reported in English literature from 1966 to 2002. Eighty-five venomous snakebites were reported in pregnant women. Although there are frequent anecdotal reports of scorpion stings in pregnant women, few case reports are documented. Other venomous animal bites or stings to pregnant women that have been reported include spiders, jellyfish, and insects, and these are described. Adverse reproductive and teratogenic effects of venoms on gravid animals are also briefly reviewed. Although uncommon, venomous bites and stings during pregnancy may have significant adverse effects on the fetus and the mother. PMID:15473462

  4. Assembly of the cnidarian camera-type eye from vertebrate-like components

    PubMed Central

    Kozmik, Zbynek; Ruzickova, Jana; Jonasova, Kristyna; Matsumoto, Yoshifumi; Vopalensky, Pavel; Kozmikova, Iryna; Strnad, Hynek; Kawamura, Shoji; Piatigorsky, Joram; Paces, Vaclav; Vlcek, Cestmir

    2008-01-01

    Animal eyes are morphologically diverse. Their assembly, however, always relies on the same basic principle, i.e., photoreceptors located in the vicinity of dark shielding pigment. Cnidaria as the likely sister group to the Bilateria are the earliest branching phylum with a well developed visual system. Here, we show that camera-type eyes of the cubozoan jellyfish, Tripedalia cystophora, use genetic building blocks typical of vertebrate eyes, namely, a ciliary phototransduction cascade and melanogenic pathway. Our findings indicative of parallelism provide an insight into eye evolution. Combined, the available data favor the possibility that vertebrate and cubozoan eyes arose by independent recruitment of orthologous genes during evolution. PMID:18577593

  5. Emerging fluorescent protein technologies.

    PubMed

    Enterina, Jhon Ralph; Wu, Lanshi; Campbell, Robert E

    2015-08-01

    Fluorescent proteins (FPs), such as the Aequorea jellyfish green FP (GFP), are firmly established as fundamental tools that enable a wide variety of biological studies. Specifically, FPs can serve as versatile genetically encoded markers for tracking proteins, organelles, or whole cells, and as the basis for construction of biosensors that can be used to visualize a growing array of biochemical events in cells and tissues. In this review we will focus on emerging applications of FPs that represent unprecedented new directions for the field. These emerging applications include new strategies for using FPs in biosensing applications, and innovative ways of using FPs to manipulate protein function or gene expression. PMID:26043278

  6. Dangers in the ocean: the traveler and marine envenomation. II. Marine vertebrates.

    PubMed

    Fenner, P J

    1998-12-01

    Envenomation both from jellyfish and other marine animals causes human deaths and severe morbidity in many countries in the world having tropical, or subtropical waters. In part II the world distribution of venomous marine vertebrates is discussed, together with simple first aid and effective medical treatment. Suggestions are made for the awareness and prevention of marine envenomation. With travel becoming more popular than ever, general practitioners and travel medicine consultants must routinely advise their patients on the worldwide hazards of marine envenomation. PMID:9876198

  7. Meteorona kishinouyei, a new family, genus and species (Cnidaria, Cubozoa, Chirodropida) from Japanese Waters

    PubMed Central

    Toshino, Sho; Miyake, Hiroshi; Shibata, Haruka

    2015-01-01

    Abstract A new family, genus and species of cubozoan box jellyfish belonging to the order Chirodropida is reported from the eastern Japan. Meteorona kishinouyei gen. et sp. n. possesses the following unique morphological characters with respect to other known species in the Chirodropida: having one tentacle per scalpel-like unbranched pedalium and slightly raised unbranched gastric saccules. A comparative table of the primary diagnostic characters of genus and order in the Chirodropida is given. The order Chirodropida is redefined. The family Chiropsellidae is established. Discussion is provided on the implications for these findings on our current understanding of Cubozoan systematics. PMID:26019668

  8. Design considerations for an underwater soft-robot inspired from marine invertebrates.

    PubMed

    Krieg, Michael; Sledge, Isaac; Mohseni, Kamran

    2015-12-01

    This article serves as an overview of the unique challenges and opportunities made possible by a soft, jellyfish inspired, underwater robot. We include a description of internal pressure modeling as it relates to propulsive performance, leading to a desired energy-minimizing volume flux program. Strategies for determining optimal actuator placement derived from biological body motions are presented. In addition a feedback mechanism inspired by the epidermal line sensory system of cephalopods is presented, whereby internal pressure distribution can be used to determine pertinent deformation parameters. PMID:26513603

  9. Venomous marine animals of Florida: morphology, behavior, health hazards.

    PubMed

    Schwartz, S; Meinking, T

    1997-10-01

    This article reviews the dangers related to marine animal envenomations in Florida. Venomous marine animals exhibit diverse mechanisms of injury and toxicity. Information regarding the morphology, behavior, and health hazards of these dangerous organisms is presented to help medical personnel recognize, diagnose and treat marine envenomations. Hazardous marine animals discussed in this review include both invertebrates and vertebrates. Stinging invertebrate animals include sponges, coelenterates (jellyfish, hydroids, corals, and sea anemones), echinoderms (sea urchins, starfish and sea cucumbers), annelid worms (bristleworm), and mollusks (cone shells, octopi and nudibranches). Stinging vertebrates discussed include stingrays, catfish, scorpionfish, and leatherjacks. PMID:9360353

  10. Venomous bites, stings, and poisoning.

    PubMed

    Warrell, David A

    2012-06-01

    This article discusses the epidemiology, prevention, clinical features, first aid and medical treatment of venomous bites by snakes, lizards, and spiders; stings by fish, jellyfish, echinoderms, and insects; and poisoning by fish and molluscs, in all parts of the world. Of these envenoming and poisonings, snake bite causes the greatest burden of human suffering, killing 46,000 people each year in India alone and more than 100,000 worldwide and resulting in physical handicap in many survivors. Specific antidotes (antivenoms/antivenins) are available to treat envenoming by many of these taxa but supply and distribution is inadequate in many tropical developing countries. PMID:22632635

  11. New Breed of Mice May Improve Accuracy for Preclinical Testing of Cancer Drugs | Poster

    Cancer.gov

    A new breed of lab animals, dubbed “glowing head mice,” may do a better job than conventional mice in predicting the success of experimental cancer drugs—while also helping to meet an urgent need for more realistic preclinical animal models. The mice were developed to tolerate often-used light-emitting molecules, such as luciferase from fireflies and green fluorescent protein (GFP) from jellyfish. These “optical reporters” are useful for monitoring the effect of experimental therapies in live animals over time because they emit an immediate and easily detected light signal showing whether a tumor inside the animal’s body is shrinking as desired.

  12. Life sciences get important new data from Spacelab mission. III

    NASA Technical Reports Server (NTRS)

    Schuiling, Roelof L.; Young, Steven

    1991-01-01

    An investigation of the effects of weightlessness on the human body is reported that was conducted on a flight of the Space Shuttle Columbia. Experiments are described regarding zero-gravity effects on the human perception of balance, the growth of lymphocytes, and general life-sciences examinations of body mass, body fluid, pulmonary parameters, and echocardiograph imaging. Specific attention is given to the day-to-day operations of the mission, and particular emphasis is given to the study of rodents and jellyfish reacting to microgravity.

  13. Environmental dermatology: skin manifestations of injuries caused by invertebrate aquatic animals*

    PubMed Central

    Haddad Junior, Vidal

    2013-01-01

    Contact between humans and coastal areas has increased in recent decades, which has led to an increase in injuries from aquatic animals. The majority of these present dermatological manifestations, and some of them show typical lesions. The highest percentages of injuries that occur in marine environments are associated with invertebrates such as sea urchins, jellyfish and Portuguese men-of-war (echinoderms and cnidarians). In this review, we discuss the clinical, therapeutic and preventive aspects of injuries caused by marine and freshwater invertebrates, focusing on first aid measures and diagnosis for dermatologists and professionals in coastal areas. PMID:24068119

  14. Medical grand rounds. West Virginia University Health Sciences Center. Bites and stings. Part 1. Spiders.

    PubMed

    Ullrich, I H

    1989-04-01

    Most animals can bite or sting. In narrowing the kingdom down to those that harm humans, the field still is vast. It would be interesting to explore the rich variety of pathology produced in us by moray eels, lionfish, sea urchins, jellyfish, sting rays, fire ants, kissing bugs, flies, lice, mosquitoes, ticks, mites, fleas, puss caterpillars, centipedes, snakes, dogs and cats, camels, and myriad other creatures including homo sapiens (not a trivial biter)--but for this grand rounds, the topic will simply be spiders (Part 1), bees and vespid (Part 2). Vespids are the wasps, yellow jackets and hornets. PMID:2718467

  15. The secretory membrane system studied in real-time. Robert Feulgen Prize Lecture, 2001.

    PubMed

    Lippincott-Schwartz, J

    2001-08-01

    The discovery and development of green fluorescent protein (GFP) from the jellyfish, Aequorea victoria, has revolutionized studies on protein localization and dynamics by allowing direct observation of a protein's life history and pathway in living cells, previously only deduced from genetic, biochemical, or immunolabeling studies. Applied to the secretory membrane system, which regulates delivery of newly synthesized proteins and lipids to the cell surface, GFP-based studies are providing important new insights into the maintenance and biogenesis of organelles, as well as the origin, pathway, and fate of secretory transport intermediates. PMID:11685538

  16. Bites and stings in travellers

    PubMed Central

    Reid, H. Alistair

    1975-01-01

    As a rule, bites and stings in travellers are merely a nuisance. But it is sensible to be informed about the more serious possibilities which can result. Systemic diseases can be transmitted, the skin lesions from insects can be troublesome and finally, some bites and stings can cause envenoming. Thus, the bather may be harmed by venomous fish stings, sea urchins, jellyfish and in Asian-Pacific waters by sea-snakes. Land hazards include bites or stings by scorpions, spiders, ticks, centipedes, bees, wasps, caterpillars and snakes. The main clinical features of such bites and stings, including treatment and prevention, are outlined. PMID:1239754

  17. Evolutionary crossroads in developmental biology: Cnidaria

    PubMed Central

    Technau, Ulrich; Steele, Robert E.

    2011-01-01

    There is growing interest in the use of cnidarians (corals, sea anemones, jellyfish and hydroids) to investigate the evolution of key aspects of animal development, such as the formation of the third germ layer (mesoderm), the nervous system and the generation of bilaterality. The recent sequencing of the Nematostella and Hydra genomes, and the establishment of methods for manipulating gene expression, have inspired new research efforts using cnidarians. Here, we present the main features of cnidarian models and their advantages for research, and summarize key recent findings using these models that have informed our understanding of the evolution of the developmental processes underlying metazoan body plan formation. PMID:21389047

  18. Irukandji syndrome: a widely misunderstood and poorly researched tropical marine envenoming.

    PubMed

    Carrette, Teresa J; Underwood, Avril H; Seymour, Jamie E

    2012-12-01

    Irukandji syndrome is a poorly defined set of symptoms that occur after envenoming by certain species of jellyfish, primarily cubozoans or 'box jellyfish'. Envenomed victims can show symptoms ranging from headaches, severe pain, nausea and vomiting to pulmonary oedema, cardiac failure and severe hypertension resulting in death. Historically, this syndrome appears to have been misdiagnosed and reported cases are undoubtedly a significant underestimation of the prevalence of this syndrome. The variation in symptoms has resulted in a myriad of treatments though none has been established as definitive. Effective pain relief with opioids is the most immediate priority. Although the annual numbers of envenomations are generally low, the associated financial costs of this envenomation may be comparatively high, with suggestions that it could run to millions of dollars per season in northern Australia alone. The syndrome has been well documented from many areas along the east coast of northern Australia, leading to the belief that it is an Australian oddity. However, with an increase in medical knowledge and improved diagnosis of the condition, it appears that envenomations causing Irukandji syndrome are an increasing marine problem worldwide. PMID:23258458

  19. Simulation of optically conditioned retention and mass occurrences of Periphylla periphylla

    PubMed Central

    Dupont, Nicolas; Aksnes, Dag L.

    2010-01-01

    Jellyfish blooms are of increasing concern in many parts of the world, and in Norwegian fjords an apparent increase in mass occurrences of the deep water jellyfish Periphylla periphylla has attracted attention. Here we investigate the hypothesis that changes in the water column light attenuation might cause local retention and thereby facilitate mass occurrences. We use a previously tested individual-based model of light-mediated vertical migration in P. periphylla to simulate how retention is affected by changes in light attenuation. Our results suggest that light attenuation, in combination with advection, has a two-sided effect on retention and that three fjord categories can be defined. In category 1, increased light attenuation turns fjords into dark “deep-sea” environments which increase the habitat and retention of P. periphylla. In category 2, an optimal light attenuation facilitates the maximum retention and likelihood for mass occurrences. In category 3, further increase in light attenuation, however, shoals the habitat so that individuals are increasingly exposed to advection and this results in loss of individuals and decreased retention. This classification requires accurate determinations of the organism's light preference, the water column light attenuation and topographical characteristics affecting advection. PMID:20454515

  20. Novel aplanatic designs for LED concentration

    NASA Astrophysics Data System (ADS)

    Ricketts, Melissa; Winston, Roland; Jiang, Lun

    2014-09-01

    Aplanats make great concentrators because of their near perfect imaging. Aplanatic conditions can be satisfied using two surface curves (generally mirrored surfaces) in two dimensions (see Figure 1) which are constructed by successive approximation to create a highly efficient concentrator for both concentration and illumination. For concentration purposes, having a two mirror system would be impossible because the front mirror would block incoming light (see figure 2) so the idea is to replace the front mirror with a "one-way" mirror. Light from a lower index can be transmitted, so if the aplanat surface is a higher index light is allowed to enter, and be trapped. In the Jellyfish design, TIR takes place except for light striking the surface within the range of critical angles. To combat that, a small area of reflective coating is applied to the central top part of the Jellyfish, where TIR fails (In the middle) to keep the light there from directly escaping (see figure 3). The design works in both forwards and reverse. Light entering can be focused to a collecter, or the collecter can be replaced with a light source to concentrate light out. In this case, LEDs are used for their highly efficienct properties.

  1. The nematocysts venom of Chrysaora helvola Brandt leads to apoptosis-like cell death accompanied by uncoupling of oxidative phosphorylation.

    PubMed

    Qu, Xiaosheng; Fan, LanLan; Zhong, Taozheng; Li, Gang; Xia, Xianghua; Long, Hairong; Huang, Danna; Shu, Wei

    2016-02-01

    The present work investigated the effects of the nematocysts venom (NV) from the Chrysaora helvola Brandt (C. helvola) jellyfish on the human nasopharyngeal carcinoma cell line, CNE-2. The medium lethal concentration (LC50), quantified by MTT assays, was 1.7 ± 0.53 μg/mL (n = 5). An atypical apoptosis-like cell death was confirmed by LDH release assay and Annexin V-FITC/PI staining-based flow cytometry. Interestingly, activation of caspase-4 other than caspase-3, -8, -9 and -1 was observed. Moreover, the NV stimuli caused a time-dependent loss of mitochondrial membrane potential (ΔΨm) as was an intracellular ROS burst. These results indicated that there was uncoupling of oxidative phosphorylation (UOP). An examination of the intracellular pH value by a pH-sensitive fluorescent probe, BCECF, suggested that the UOP was due to the time-dependent increase in the intracellular pH. This is the first report that jellyfish venom can induce UOP. PMID:26718259

  2. A new method for the separation of different types of nematocysts from scyphozoa and investigation of proteinaceous toxins utilizing laser catapulting and subsequent mass spectrometry.

    PubMed

    Wiebring, Annika; Helmholz, Heike; Sötje, Ilka; Lassen, Stephan; Prange, Andreas; Tiemann, Henry

    2010-06-01

    Jellyfish have an increasing impact on marine ecology. Cnidocysts bearing stinging cells afford, amongst others, prey capture and defence. Several different types of stinging capsules are found in one species and they are supposed to have specific functions, e.g. paralysing prey or adhering to it. Due to these assumed different roles of the capsules, it is suggested that toxins, which are contained in the capsules, differ in composition. Analysis of distinct types of nematocysts requires an appropriate method for the separation of the different types. Mixtures of types of nematocysts were obtained of two species of jellyfish, Aurelia aurita and Cyanea lamarckii, by maceration of the tissue. These mixtures were treated with a method called laser microdissection and pressure catapulting (LMPC). Optimized maceration methods, which were firstly introduced as a method for this purpose, in conjunction with optimized LMPC parameters lead to sufficient amounts of separated capsules of individual types for subsequent mass-spectrometric analyses. In case of A. aurita, the resulting mass spectra had some constituents in common, whereas in the overall pattern, the two distinct nematocyst types differed. PMID:20336340

  3. DNA sequence organization in the genomes of five marine invertebrates.

    PubMed

    Goldberg, R B; Crain, W R; Ruderman, J V; Moore, G P; Barnett, T R; Higgins, R C; Gelfand, R A; Galau, G A; Britten, R J; Davidson, E H

    1975-07-21

    The arrangement of repetitive and non-repetitive sequence was studied in the genomic DNA of the oyster (Crassostrea virginica), the surf clam (Spisula solidissima), the horseshoe crab (Limulus polyphemus), a nemertean worm (Cerebratulus lacteus) and a jelly-fish (Aurelia aurita). Except for the jellyfish these animals belong to the protostomial branch of animal evolution, for which little information regarding DNA sequence organization has previously been available. The reassociation kinetics of short (250-300 nucleotide) and long (2,000-3,000 nucleotide) DNA fragments was studied by the hydroxyapatite method. It was shown that in each case a major fraction of the DNA consists of single copy sequences less than about 3,000 nucleotides in length, interspersed with short repetitive sequences. The lengths of the repetitive sequences were estimated by optical hyperchromicity and S1 nuclease measurements made on renaturation products. All the genomes studied include a prominent fraction of interspersed repetitive sequences about 300 nucleotides in length, as well as longer repetitive sequence regions. PMID:238802

  4. Electrogenesis in the lower Metazoa and implications for neuronal integration.

    PubMed

    Meech, Robert W

    2015-02-15

    Electrogenic communication appears to have evolved independently in a variety of animal and plant lineages. Considered here are metazoan cells as disparate as the loose three-dimensional parenchyma of glass sponges, the two-dimensional epithelial sheets of hydrozoan jellyfish and the egg cell membranes of the ctenophore Beroe ovata, all of which are capable of generating electrical impulses. Neuronal electrogenesis may have evolved independently in ctenophores and cnidarians but the dearth of electrophysiological data relating to ctenophore nerves means that our attention is focused on the Cnidaria, whose nervous systems have been the subject of extensive study. The aim here is to show how their active and passive neuronal properties interact to give integrated behaviour. Neuronal electrogenesis, goes beyond simply relaying 'states of excitement' and utilizes the equivalent of a set of basic electrical 'apps' to integrate incoming sensory information with internally generated pacemaker activity. A small number of membrane-based processes make up these analogue applications. Passive components include the decremental spread of current determined by cellular anatomy; active components include ion channels specified by their selectivity and voltage dependence. A recurring theme is the role of inactivating potassium channels in regulating performance. Although different aspects of cnidarian behaviour are controlled by separate neuronal systems, integrated responses and coordinated movements depend on interactions between them. Integrative interactions discussed here include those between feeding and swimming, between tentacle contraction and swimming and between slow and fast swimming in the hydrozoan jellyfish Aglantha digitale. PMID:25696817

  5. Fluorescence lifetime imaging of coral fluorescent proteins.

    PubMed

    Cox, Guy; Matz, Mikhail; Salih, Anya

    2007-03-01

    Corals, like many other coelenterates, contain fluorescent pigments that show considerable homology with the well known green fluorescent protein of the jellyfish Aequoria. In corals, unlike jellyfish, multiple proteins are present and the range of excitations and emissions suggest the possibility of energy transfer. The occurrence of Förster resonant energy transfer (FRET) between fluorescent proteins in corals has already been reported and time-resolved spectra have shown the effect on fluorescent lifetime, but without any spatial resolution. Lifetime confocal microscopy offers lower time resolution but excellent spatial resolution. Lifetimes of the isolated A. millepora pigments amilFP490, amilFP504, and amilFP593 (names indicate emission peaks) were 2.8, 2.9, and 2.9 ns, respectively. In the coral sample, imaging the entire emission spectrum from 420 nm, the mean lifetime was reduced to 1.5 ns, implying that FRET was occurring. Looking just at the fluorescence from FRET donors the lifetime was even shorter, at 1.3 ns, supporting this interpretation. In contrast, no reduction in lifetime is seen in the coral Euphyllia ancora, where the pigment distribution also suggests that the pigments are unlikely to be involved in photoprotection. This study set out to determine the extent of FRET between pigments in two corals, Acropora millepora and Euphyllia, ancora which differ in the arrangement of their pigments and hence possibly in pigment function. PMID:17279514

  6. Stimulated bacterioplankton growth and selection for certain bacterial taxa in the vicinity of the ctenophore Mnemiopsis leidyi

    PubMed Central

    Dinasquet, Julie; Granhag, Lena; Riemann, Lasse

    2012-01-01

    Episodic blooms of voracious gelatinous zooplankton, such as the ctenophore Mnemiopsis leidyi, affect pools of inorganic nutrients and dissolved organic carbon by intensive grazing activities and mucus release. This will potentially influence bacterioplankton activity and community composition, at least at local scales; however, available studies on this are scarce. In the present study we examined effects of M. leidyi on bacterioplankton growth and composition in incubation experiments. Moreover, we examined community composition of bacteria associated with the surface and gut of M. leidyi. High release of ammonium and high bacterial growth was observed in the treatments with M. leidyi relative to controls. Deep 454 pyrosequencing of 16 S rRNA genes showed specific bacterial communities in treatments with M. leidyi as well as specific communities associated with M. leidyi tissue and gut. In particular, members of Flavobacteriaceae were associated with M. leidyi. Our study shows that M. leidyi influences bacterioplankton activity and community composition in the vicinity of the jellyfish. In particular during temporary aggregations of jellyfish, these local zones of high bacterial growth may contribute significantly to the spatial heterogeneity of bacterioplankton activity and community composition in the sea. PMID:22912629

  7. Development of a quantitative real-time PCR for the detection of Tenacibaculum maritimum and its application to field samples.

    PubMed

    Fringuelli, E; Savage, P D; Gordon, A; Baxter, E J; Rodger, H D; Graham, D A

    2012-08-01

    The development and the application of a quantitative real-time PCR for the detection of Tenacibaculum maritimum are described. A set of primers and probe was designed to amplify a 155-bp fragment specific to the T. maritimum 16S rRNA gene. The test was shown to be very sensitive, able to detect as little as 4.8 DNA copies number μL(-1) . In addition, the assay was found to have a high degree of repeatability and reproducibility, with a linear dynamic range (R(2)  = 0.999) extending over 6 log(10) dilutions and a high efficiency (100%). The assay was applied to DNA samples extracted from 48 formalin-fixed paraffin-embedded (FFPE) Atlantic salmon, Salmo salar, gill tissues showing varying degrees of gill pathology (scored 0-3) and from 26 jellyfish samples belonging to the species Phialella quadrata and Muggiaea atlantica. For each sample, the bacterial load was normalised against the level of the salmonid elongation factor alpha 1 (ELF) detected by a second real-time PCR using previously published primers and probe. Tenacibaculum maritimum DNA was detected in 89% of the blocks with no signs of gill disease as well as in 95% of the blocks with mild-to-severe gill pathology. Association between bacterial load and gill pathology severity was investigated. T. maritimum DNA was detected at low level in four of the 26 jellyfish tested. PMID:22724390

  8. Electrogenesis in the lower Metazoa and implications for neuronal integration

    PubMed Central

    Meech, Robert W.

    2015-01-01

    Electrogenic communication appears to have evolved independently in a variety of animal and plant lineages. Considered here are metazoan cells as disparate as the loose three-dimensional parenchyma of glass sponges, the two-dimensional epithelial sheets of hydrozoan jellyfish and the egg cell membranes of the ctenophore Beroe ovata, all of which are capable of generating electrical impulses. Neuronal electrogenesis may have evolved independently in ctenophores and cnidarians but the dearth of electrophysiological data relating to ctenophore nerves means that our attention is focused on the Cnidaria, whose nervous systems have been the subject of extensive study. The aim here is to show how their active and passive neuronal properties interact to give integrated behaviour. Neuronal electrogenesis, goes beyond simply relaying ‘states of excitement’ and utilizes the equivalent of a set of basic electrical ‘apps’ to integrate incoming sensory information with internally generated pacemaker activity. A small number of membrane-based processes make up these analogue applications. Passive components include the decremental spread of current determined by cellular anatomy; active components include ion channels specified by their selectivity and voltage dependence. A recurring theme is the role of inactivating potassium channels in regulating performance. Although different aspects of cnidarian behaviour are controlled by separate neuronal systems, integrated responses and coordinated movements depend on interactions between them. Integrative interactions discussed here include those between feeding and swimming, between tentacle contraction and swimming and between slow and fast swimming in the hydrozoan jellyfish Aglantha digitale. PMID:25696817

  9. Star formation in shocked cluster spirals and their tails

    NASA Astrophysics Data System (ADS)

    Roediger, E.; Brüggen, M.; Owers, M. S.; Ebeling, H.; Sun, M.

    2014-09-01

    Recent observations of ram pressure stripped spiral galaxies in clusters revealed details of the stripping process, i.e. the truncation of all interstellar medium phases and of star formation (SF) in the disc, and multiphase star-forming tails. Some stripped galaxies, in particular in merging clusters, develop spectacular star-forming tails, giving them a jellyfish-like appearance. In merging clusters, merger shocks in the intracluster medium (ICM) are thought to have overrun these galaxies, enhancing the ambient ICM pressure and thus triggering SF, gas stripping, and tail formation. We present idealized hydrodynamical simulations of this scenario, including standard descriptions for SF and stellar feedback. To aid the interpretation of recent and upcoming observations, we focus on particular structures and dynamics in SF patterns in the remaining gas disc and in the near tails, which are easiest to observe. The observed jellyfish morphology is qualitatively reproduced for, both, face-on and edge-on stripping. In edge-on stripping, the interplay between the ICM wind and the disc rotation leads to asymmetries along the ICM wind direction and perpendicular to it. The apparent tail is still part of a highly deformed gaseous and young stellar disc. In both geometries, SF takes place in knots throughout the tail, such that the stars in the tails show no ordered age gradients. Significant SF enhancement in the disc occurs only at radii where the gas will be stripped in due course.

  10. Evolution of an ancient venom: recognition of a novel family of cnidarian toxins and the common evolutionary origin of sodium and potassium neurotoxins in sea anemone.

    PubMed

    Jouiaei, Mahdokht; Sunagar, Kartik; Federman Gross, Aya; Scheib, Holger; Alewood, Paul F; Moran, Yehu; Fry, Bryan G

    2015-06-01

    Despite Cnidaria (sea anemones, corals, jellyfish, and hydroids) being the oldest venomous animal lineage, structure-function relationships, phyletic distributions, and the molecular evolutionary regimes of toxins encoded by these intriguing animals are poorly understood. Hence, we have comprehensively elucidated the phylogenetic and molecular evolutionary histories of pharmacologically characterized cnidarian toxin families, including peptide neurotoxins (voltage-gated Na(+) and K(+) channel-targeting toxins: NaTxs and KTxs, respectively), pore-forming toxins (actinoporins, aerolysin-related toxins, and jellyfish toxins), and the newly discovered small cysteine-rich peptides (SCRiPs). We show that despite long evolutionary histories, most cnidarian toxins remain conserved under the strong influence of negative selection-a finding that is in striking contrast to the rapid evolution of toxin families in evolutionarily younger lineages, such as cone snails and advanced snakes. In contrast to the previous suggestions that implicated SCRiPs in the biomineralization process in corals, we demonstrate that they are potent neurotoxins that are likely involved in the envenoming function, and thus represent the first family of neurotoxins from corals. We also demonstrate the common evolutionary origin of type III KTxs and NaTxs in sea anemones. We show that type III KTxs have evolved from NaTxs under the regime of positive selection, and likely represent a unique evolutionary innovation of the Actinioidea lineage. We report a correlation between the accumulation of episodically adaptive sites and the emergence of novel pharmacological activities in this rapidly evolving neurotoxic clade. PMID:25757852

  11. The synthesis of mycosporine-like amino acids (MAAs) by cultured, symbiotic dinoflagellates.

    PubMed

    T Banaszak1 A; LaJeunesse; Trench

    2000-06-28

    We tested the hypothesis that there is a relation between phylotypes (phylogenetic types, as determined by restriction fragment length polymorphism (RFLP) and partial sequence analysis of the small subunit ribosomal RNA gene (SSUrDNA)) and the synthesis of mycosporine-like amino acids (MAAs) by symbiotic dinoflagellates under the influence of ultraviolet radiation (UV-B/A) and photosynthetically active radiation (PAR). We exposed 27 isolates of symbiotic dinoflagellates simultaneously to UV-B/A and PAR, and subsequently determined the MAAs present in cell extracts and in the media. The algae used included 24 isolates of Symbiodinium spp. originating from jellyfishes, sea anemones, zoanthids, scleractinians, octocorals, and bivalves, and three others in the genera Gymnodinium, Gloeodinium and Amphidinium from a jellyfish, an hydrocoral and a flatworm, respectively. In this study, all of the phylotype A Symbiodinium spp. synthesized up to three identified MAAs. None of the 11 cultured phylotypes B and C Symbiodinium spp. synthesized MAAs. The three non-Symbiodinium symbionts also synthesized up to three MAAs. The results support a conclusion that phylotype A Symbiodinium spp. have a high predilection for the synthesis of MAAs, while phylotypes B and C do not. Synthesis of MAAs by symbiotic dinoflagellates in culture does not appear to relate directly to depths or to the UV exposure regimes from which the consortia were collected. PMID:10841936

  12. Tentacle Transcriptome and Venom Proteome of the Pacific Sea Nettle, Chrysaora fuscescens (Cnidaria: Scyphozoa)

    PubMed Central

    Ponce, Dalia; Brinkman, Diane L.; Potriquet, Jeremy; Mulvenna, Jason

    2016-01-01

    Jellyfish venoms are rich sources of toxins designed to capture prey or deter predators, but they can also elicit harmful effects in humans. In this study, an integrated transcriptomic and proteomic approach was used to identify putative toxins and their potential role in the venom of the scyphozoan jellyfish Chrysaora fuscescens. A de novo tentacle transcriptome, containing more than 23,000 contigs, was constructed and used in proteomic analysis of C. fuscescens venom to identify potential toxins. From a total of 163 proteins identified in the venom proteome, 27 were classified as putative toxins and grouped into six protein families: proteinases, venom allergens, C-type lectins, pore-forming toxins, glycoside hydrolases and enzyme inhibitors. Other putative toxins identified in the transcriptome, but not the proteome, included additional proteinases as well as lipases and deoxyribonucleases. Sequence analysis also revealed the presence of ShKT domains in two putative venom proteins from the proteome and an additional 15 from the transcriptome, suggesting potential ion channel blockade or modulatory activities. Comparison of these potential toxins to those from other cnidarians provided insight into their possible roles in C. fuscescens venom and an overview of the diversity of potential toxin families in cnidarian venoms. PMID:27058558

  13. Yellow fluorescent protein phiYFPv (Phialidium): structure and structure-based mutagenesis

    SciTech Connect

    Pletneva, Nadya V.; Pletnev, Vladimir Z. Souslova, Ekaterina; Chudakov, Dmitry M.; Lukyanov, Sergey; Martynov, Vladimir I.; Arhipova, Svetlena; Artemyev, Igor; Wlodawer, Alexander; Dauter, Zbigniew; Pletnev, Sergei

    2013-06-01

    The yellow fluorescent protein phiYFPv with improved folding has been developed from the spectrally identical wild-type phiYFP found in the marine jellyfish Phialidium. The yellow fluorescent protein phiYFPv (λ{sub em}{sup max} ≃ 537 nm) with improved folding has been developed from the spectrally identical wild-type phiYFP found in the marine jellyfish Phialidium. The latter fluorescent protein is one of only two known cases of naturally occurring proteins that exhibit emission spectra in the yellow–orange range (535–555 nm). Here, the crystal structure of phiYFPv has been determined at 2.05 Å resolution. The ‘yellow’ chromophore formed from the sequence triad Thr65-Tyr66-Gly67 adopts the bicyclic structure typical of fluorophores emitting in the green spectral range. It was demonstrated that perfect antiparallel π-stacking of chromophore Tyr66 and the proximal Tyr203, as well as Val205, facing the chromophore phenolic ring are chiefly responsible for the observed yellow emission of phiYFPv at 537 nm. Structure-based site-directed mutagenesis has been used to identify the key functional residues in the chromophore environment. The obtained results have been utilized to improve the properties of phiYFPv and its homologous monomeric biomarker tagYFP.

  14. Photo-real rendering of bioluminescence and iridescence in creatures from the abyss

    NASA Astrophysics Data System (ADS)

    Prusten, Mark

    2008-08-01

    The generation of photo-real renderings of bioluminescence is developed for creatures from the abyss. Bioluminescence results from a chemical reaction with examples found in deep-sea marine environments including: algae, copepods, jellyfish, squid, and fish. In bioluminescence, the excitation energy is supplied by a chemical reaction, not by a source of light. The greatest transparency window in seawater is in the blue region of the visible spectrum. From small creatures like single-cell algae, to large species of siphonophore Praya dubia (40m), luminescent phenomena can be produced by mechanical excitement from disturbances of objects passing by. Deep sea fish, like the Pacific Black Dragonfish are covered with photophores along the upper and lower surfaces which emits light when disturbed. Other animals like small squids have several different types of light organs oscillating at different rates. Custom shaders and material phenomena incorporate indirect lighting like: global illumination, final gathering, ambient occlusion and subsurface scattering to provide photo real images. Species like the Hydomedusae jellyfish, produce colors that are also generated by iridescence of thin tissues. The modeling and rendering of these tissues requires thin film multilayer stacks. These phenomena are simulated by semi-rigid body dynamics in a procedural animation environment. These techniques have been applied to develop spectral rendering of scenes outside the normal visible window in typical computer animation render engines.

  15. Tentacle Transcriptome and Venom Proteome of the Pacific Sea Nettle, Chrysaora fuscescens (Cnidaria: Scyphozoa).

    PubMed

    Ponce, Dalia; Brinkman, Diane L; Potriquet, Jeremy; Mulvenna, Jason

    2016-01-01

    Jellyfish venoms are rich sources of toxins designed to capture prey or deter predators, but they can also elicit harmful effects in humans. In this study, an integrated transcriptomic and proteomic approach was used to identify putative toxins and their potential role in the venom of the scyphozoan jellyfish Chrysaora fuscescens. A de novo tentacle transcriptome, containing more than 23,000 contigs, was constructed and used in proteomic analysis of C. fuscescens venom to identify potential toxins. From a total of 163 proteins identified in the venom proteome, 27 were classified as putative toxins and grouped into six protein families: proteinases, venom allergens, C-type lectins, pore-forming toxins, glycoside hydrolases and enzyme inhibitors. Other putative toxins identified in the transcriptome, but not the proteome, included additional proteinases as well as lipases and deoxyribonucleases. Sequence analysis also revealed the presence of ShKT domains in two putative venom proteins from the proteome and an additional 15 from the transcriptome, suggesting potential ion channel blockade or modulatory activities. Comparison of these potential toxins to those from other cnidarians provided insight into their possible roles in C. fuscescens venom and an overview of the diversity of potential toxin families in cnidarian venoms. PMID:27058558

  16. The right tool and the right place for the job: the importance of the field in experimental neurophysiology, 1880-1945.

    PubMed

    Muka, Samantha K

    2016-09-01

    This paper seeks to contribute to understandings of practice and place in the history of early American neurophysiology by exploring research with jellyfish at marine stations. Jellyfish became a particularly important research tool to experimental physiologists studying neurological subjects at the turn of the twentieth century. But their enthusiasm for the potential of this organism was constrained by its delicacy in captivity. The discovery of hardier species made experimentation at the shore possible and resulted in two epicenters of neurophysiological research on the American East Coast: the Marine Biological Laboratory and the Carnegie Institution's Dry Tortugas Laboratory. Work done in these locations had impacts on a wide range of physiological questions. These centers were short lived-researchers at the MBL eventually focused on the squid giant axon and the Tortugas lab closed after the death of Mayer-but the development of basic requirements and best practices to sustain these organisms paints an important picture of early experimental neurophysiology. Marine organisms and locations have played an integral role in the development of experimental life sciences in America. By understanding the earliest experimental research done at these locations, and the organisms that lured researchers from the campus to the coastline, we can begin to integrate marine stations into the larger historical narrative of American physiology. PMID:27338571

  17. Mercury bioaccumulation and biomagnification in a small Arctic polynya ecosystem.

    PubMed

    Clayden, Meredith G; Arsenault, Lilianne M; Kidd, Karen A; O'Driscoll, Nelson J; Mallory, Mark L

    2015-03-15

    Recurring polynyas are important areas of biological productivity and feeding grounds for seabirds and mammals in the Arctic marine environment. In this study, we examined food web structure (using carbon and nitrogen isotopes, δ(13)C and δ(15)N) and mercury (Hg) bioaccumulation and biomagnification in a small recurring polynya ecosystem near Nasaruvaalik Island (Nunavut, Canada). Methyl Hg (MeHg) concentrations increased by more than 50-fold from copepods (Calanus hyperboreus) to Arctic terns (Sterna paradisaea), the abundant predators at this site. The biomagnification of MeHg through members of the food web - using the slope of log MeHg versus δ(15)N - was 0.157 from copepods (C. hyperboreus) to fish. This slope was higher (0.267) when seabird chicks were included in the analyses. Collectively, our results indicate that MeHg biomagnification is occurring in this small polynya and that its trophic transfer is at the lower end of the range of estimates from other Arctic marine ecosystems. In addition, we measured Hg concentrations in some poorly studied members of Arctic marine food webs [e.g. Arctic alligatorfish (Ulcina olrikii) and jellyfish, Medusozoa], and found that MeHg concentrations in jellyfish were lower than expected given their trophic position. Overall, these findings provide fundamental information about food web structure and mercury contamination in a small Arctic polynya, which will inform future research in such ecosystems and provide a baseline against which to assess changes over time resulting from environmental disturbance. PMID:25149682

  18. Recovery of fish stocks in the Seto Inland Sea.

    PubMed

    Nagai, T

    2003-01-01

    The total amount of fisheries' yield in the Seto Inland Sea in 1999 was 571,000 MT, consisting of 256,000 MT by fishing and 315,000 MT from aquaculture. About 40,000 people engaged in the fishing and aquaculture industries, earned 129 billion yen (1100 million US$) by fishing and 89 billion yen (770 million $US) by aquaculture. The averaged annual catch for the Seto Inland Sea by fishing was 13 MT/km(2). Division into time periods in terms of eutrophication levels can be made: before 1960 when red sea bream were abundant with ecological divergence (before eutrophication), from 1960 to 1990 when the biomass of anchovy was large (during eutrophication), and after 1990 when the jellyfishes were abundant (excessive eutrophication or high N:P ratio). The fish production will decrease in the sea of jellyfishes. Actually, the amount of catch was 462,000 MT in 1982 which decreased 265,000 MT in 1993, corresponding to 43% in twelve years, then keeping the same level. A big reduction was seen in the catches of the spotlined sardine, anchovy, Spanish mackerel, tiger puffer, short-necked clam, sea cucumber and others. The tiger puffer and Spanish mackerel were abundant as predators in the sea of anchovy. The biomass of anchovy was at its maximum in 1986 and decreased to less than one third in 1996. The stocks of tiger puffer and Spanish mackerel greatly decreased because of the higher fishing pressure compared to the anchovy stock. The fishing power of individual fisheries targeting on the tiger puffer and Spanish mackerel increased substantially when fishing vessel and fishing gear improved, resulting in an excessive fishing effort. A large quantity of small immature fishes is usually caught in the Seto Inland Sea, resulting in growth and/or recruitment overfishing for many species. Hence, it is necessary to promote management of the fisheries so as not to reduce the fish stocks, and to allow the Seto Inland Sea to return from being a sea of jellyfishes to a sea of anchovy

  19. Novel fluorescent protein from Hydnophora rigida possess cyano emission.

    PubMed

    Bokhari, H; Smith, C; Veerendra, K; Sivaraman, J; Sikaroodi, M; Gillevet, P

    2010-06-01

    Currently, a broad diversity of fluorescent proteins among marine organisms range from cyano-red emissions. Fluorescent proteins differ in their DNA sequences from green fluorescent protein (GFP). We identified cDNA encoding the gene of a new protein from the reef coral Hydnophora rigida of the Merulinidae family. Both the spectral properties and putative primary sequence of the protein has been determined. The cloned cDNA encode peptide we call HriCFP is comprised of 134 amino acids. It has characteristics of a cyano fluorescent protein (HriCFP) and its sequence is markedly different from known GFP from the hydroid jellyfish Aequorea victoria. HriCFP was cloned, expressed, purified and exist as monomer. The peptide mass finger print on the purified protein confirmed identity of HriCFP. PMID:20435020

  20. Fluorescence imaging in the last two decades

    PubMed Central

    Miyawaki, Atsushi

    2013-01-01

    In commemoration of the 20th anniversary of the molecular cloning of the gene for the green fluorescent protein from the jellyfish Aequorea victoria, I would like to reflect on the development of new fluorescence imaging technology in the last two decades. As this technology has become increasingly diversified, it has become more and more of a challenge to come up with a comprehensive and exhaustive review of it. Here I will focus on optogenetics and large-scale, three-dimensional reconstruction. Those two technological innovations have been achieved in the neuroscience community owing to the combined efforts of molecular biologists and light microscopists. In addition, modern fluorescence imaging has indeed improved our understanding of the spatiotemporal regulation of fundamental biological functions at cellular level. As an example, I will introduce some findings we made regarding the movement of biomolecules across the nuclear membrane. The above-mentioned imaging approaches are possible today but were impossible two decades ago. PMID:23393311

  1. Suction-based propulsion as a basis for efficient animal swimming.

    PubMed

    Gemmell, Brad J; Colin, Sean P; Costello, John H; Dabiri, John O

    2015-01-01

    A central and long-standing tenet in the conceptualization of animal swimming is the idea that propulsive thrust is generated by pushing the surrounding water rearward. Inherent in this perspective is the assumption that locomotion involves the generation of locally elevated pressures in the fluid to achieve the expected downstream push of the surrounding water mass. Here we show that rather than pushing against the surrounding fluid, efficient swimming animals primarily pull themselves through the water via suction. This distinction is manifested in dominant low-pressure regions generated in the fluid surrounding the animal body, which are observed by using particle image velocimetry and a pressure calculation algorithm applied to freely swimming lampreys and jellyfish. These results suggest a rethinking of the evolutionary adaptations observed in swimming animals as well as the mechanistic basis for bio-inspired and biomimetic engineered vehicles. PMID:26529342

  2. Fully resolved simulation of self-propulsion of aquatic organisms

    NASA Astrophysics Data System (ADS)

    Curet, Oscar M.; Alali, Ibrahim; Patankar, Neelesh A.; Maciver, Malcolm A.

    2008-11-01

    We present a computational approach for fully resolved simulation of self-propulsion of organisms through a fluid. Our implicit algorithm solves for the translational and rotational motion of the organism for prescribed deformation kinematics. In addition, the solution for the surrounding flow field is also obtained. The approach is easy to apply to the body forms of a variety of organisms. Our final goal is to use this computational tool to help in understanding the mechanisms of movement and its control in aquatic animals. In this abstract we present validation of this method for different organisms. To validate the method with respect to analytical solutions, we consider two cases: 1) a flagellum which propagates plane waves, and 2) a flagellum that propagates helical waves. To validate the method with respect to empirical measurements we consider data from two organisms: 1) jellyfish (data from John Dabiri at Caltech), and 2) zebrafish (data from Melina Hale at The University of Chicago).

  3. Fabrication and observation of nanowire-assemblages of Si-Ge

    NASA Astrophysics Data System (ADS)

    Hu, Q.; Araki, H.; Suzuki, H.; Ishikawa, N.; Yang, W.; Noda, T.

    A few of the interesting structures made by the assemblage of Si-Ge nanowires fabricated by the floating-zone melting-vapor method have been observed. They reveal shapes that are similar to coral, jellyfish and sea anemones. The pre-sintered substrate bar has some large crystalline particles (1-15 μm), which produce sites that are energetically predisposed to nucleation. The peculiar structures created by the assemblage of Si-Ge nanowires form on favored nucleation sites that consist of numerous bundles of nanowires with diameters of 20-50 nm. The periodic variation in the diameter of the bundles of nanowires is a common feature of these structures. In addition, a growth mechanism assisted by the coexistence of Ge and Si-Ge oxides is suggested. The growth process of these assemblages opens up new possibilities for the study of the growth mechanism of Si-Ge nanowires.

  4. Proton mediated control of biochemical reactions with bioelectronic pH modulation.

    PubMed

    Deng, Yingxin; Miyake, Takeo; Keene, Scott; Josberger, Erik E; Rolandi, Marco

    2016-01-01

    In Nature, protons (H(+)) can mediate metabolic process through enzymatic reactions. Examples include glucose oxidation with glucose dehydrogenase to regulate blood glucose level, alcohol dissolution into carboxylic acid through alcohol dehydrogenase, and voltage-regulated H(+) channels activating bioluminescence in firefly and jellyfish. Artificial devices that control H(+) currents and H(+) concentration (pH) are able to actively influence biochemical processes. Here, we demonstrate a biotransducer that monitors and actively regulates pH-responsive enzymatic reactions by monitoring and controlling the flow of H(+) between PdHx contacts and solution. The present transducer records bistable pH modulation from an "enzymatic flip-flop" circuit that comprises glucose dehydrogenase and alcohol dehydrogenase. The transducer also controls bioluminescence from firefly luciferase by affecting solution pH. PMID:27052724

  5. Prospects for the gliding mechanism of Mycoplasma mobile.

    PubMed

    Miyata, Makoto; Hamaguchi, Tasuku

    2016-02-01

    Mycoplasma mobile forms gliding machinery at a cell pole and glides continuously in the direction of the cell pole at up to 4.5μm per second on solid surfaces such as animal cells. This motility system is not related to those of any other bacteria or eukaryotes. M. mobile uses ATP energy to repeatedly catch, pull, and release sialylated oligosaccharides on host cells with its approximately 50-nm long legs. The gliding machinery is a large structure composed of huge surface proteins and internal jellyfish-like structure. This system may have developed from an accidental combination between an adhesin and a rotary ATPase, both of which are essential for the adhesive parasitic life of Mycoplasmas. PMID:26500189

  6. Species associations and redundancy in relation to biological hotspots within the northern California Current ecosystem

    NASA Astrophysics Data System (ADS)

    Reese, Douglas C.; Brodeur, Richard D.

    2015-06-01

    The dynamic nature of biological hotspots, while well recognized, is not well understood. We hypothesize that the persistence of hotspots in the northern California Current System (CCS), despite seasonal and annual changes in the nekton community species composition, is related to associations among species and their functional redundancy. To address this hypothesis, sampling was conducted during June and August of 2000 and 2002 within two hotspots occurring between Newport, Oregon and Crescent City, California in the coastal CCS. Associations were examined to identify potentially complementary and redundant species. The strongest negative associations were between jellyfish and fish species, with strong positive associations evident among several fish species. Dominant species varied seasonally and annually, although evidence indicated replacement of dominant species by other similar species with respect to functional group and preferred habitat. This finding suggests that the persistence of these biological hotspots is related to species redundancy and is an important attribute contributing to stability within this highly variable system.

  7. Aurelia aurita bio-inspired tilt sensor

    NASA Astrophysics Data System (ADS)

    Smith, Colin; Villanueva, Alex; Priya, Shashank

    2012-10-01

    The quickly expanding field of mobile robots, unmanned underwater vehicles, and micro-air vehicles urgently needs a cheap and effective means for measuring vehicle inclination. Commonly, tilt or inclination has been mathematically derived from accelerometers; however, there is inherent error in any indirect measurement. This paper reports a bio-inspired tilt sensor that mimics the natural balance organ of jellyfish, called the ‘statocyst’. Biological statocysts from the species Aurelia aurita were characterized by scanning electron microscopy to investigate the morphology and size of the natural sensor. An artificial tilt sensor was then developed by using printed electronics that incorporates a novel voltage divider concept in conjunction with small surface mount devices. This sensor was found to have minimum sensitivity of 4.21° with a standard deviation of 1.77°. These results open the possibility of developing elegant tilt sensor architecture for both air and water based platforms.

  8. Reprint of “Prospects for the gliding mechanism of Mycoplasma mobile”.

    PubMed

    Miyata, Makoto; Hamaguchi, Tasuku

    2015-12-01

    Mycoplasma mobile forms gliding machinery at a cell pole and glides continuously in the direction of the cell pole at up to 4.5 μm per second on solid surfaces such as animal cells. This motility system is not related to those of any other bacteria or eukaryotes. M. mobile uses ATP energy to repeatedly catch, pull, and release sialylated oligosaccharides on host cells with its approximately 50-nm long legs. The gliding machinery is a large structure composed of huge surface proteins and internal jellyfish-like structure. This system may have developed from an accidental combination between an adhesin and a rotary ATPase, both of which are essential for the adhesive parasitic life of Mycoplasmas. PMID:26711226

  9. Perturbation response of model vortex rings and dipoles

    NASA Astrophysics Data System (ADS)

    O'Farrell, Clara; Dabiri, John O.

    2012-11-01

    Jetting swimmers, such as squid or jellyfish, propel themselves by forming axisymmetric vortex rings. It is known that vortex rings cannot grow indefinitely, but rather ``pinch off'' once they reach their physical limit, and that a decrease in efficiency of fluid transport is associated with pinch-off. In contrast, two-dimensional vortex dipoles have been found to grow well beyond the physical limit observed in axisymmetric vortex rings. Previously, the Norbury and Pierrehumbert families of vortices have been used as models for axisymmetric vortex rings and two-dimensional dipoles respectively, and the response of these two families to shape perturbations has been characterized. In this study, we improve upon the Norbury and Pierrehumbert models, using nested contours to obtain more realistic models for experimentally-generated vortex rings and dipoles. The resulting vortices are subjected to shape perturbations akin to those previously introduced to members of the Norbury and Pierrehumbert families, and their response is characterized.

  10. Evaluation of a GFP Report Gene Construct for Environmental Arsenic Detection

    SciTech Connect

    Roberto, F.F.; Barnes, J.M.; Bruhn, D.F.

    2002-03-28

    Detection of arsenic and other heavy metal contaminants in the environment is critical to ensuring safe drinking water and effective cleanup of historic activities that have led to widespread contamination of soil and groundwater. Biosensors have the potential to significantly reduce the costs associated with site characterization and long term environmental monitoring. By exploiting the highly selective and sensitive natural mechanisms by which bacteria and other living organisms respond to heavy metals, and fusing transcriptionally active components of these mechanisms to reporter genes, such as B-galactosidase, bacterial luciferase (lux), or green fluorescent protein (GFP) from marine jellyfish, it is possible to produce inexpensive, yet effective biosensors. This article describes the response to submicrogram quantities of arsenite and arsenate of a whole cell arsenic biosensor utilizing a GFP reporter gene.

  11. Variability of satellite derived chlorophyll-a in the southern Caspian Sea following an invasion of ctenophore Mnemiopsis leidyi

    NASA Astrophysics Data System (ADS)

    Moradi, Masoud

    2013-01-01

    The comb jellyfish Mnemiopsis leidyi invaded vastly the whole Caspian Sea in summer 2001. Sea-viewing wide field-of-view sensor and moderate resolution imaging spectroradiometer (MODIS) satellite data from 1998 to 2006 and bio-optical field measurements along six transects in the southern Caspian Sea from 2001 to 2006 were used to detect the relationships between M. leidyi abundances with satellite driven sea surface temperature (SST) and chlorophyll-a. MODIS chlorophyll-a and SST monthly composite average value showed a positive linear correlation with M. leidyi abundance in the southern Caspian Sea. Spatiotemporal distribution of MODIS chlorophyll-a high-level patches (˜5 mg.m-3) were also confirmed with the highest recorded M. leidyi and the lowest zooplankton abundances. However, there are several other factors that affect the concentration of chlorophyll-a, and it is not clear how much of the chlorophyll-a variation is related to M. leidyi abundances.

  12. Dynamics and self-propulsion of a spherical body shedding coaxial vortex rings in an ideal fluid

    NASA Astrophysics Data System (ADS)

    Tallapragada, Phanindra; Kelly, Scott David

    2013-01-01

    We describe a model for the dynamic interaction of a sphere with uniform density and a system of coaxial circular vortex rings in an ideal fluid of equal density. At regular intervals in time, a constraint is imposed that requires the velocity of the fluid relative to the sphere to have no component transverse to a particular circular contour on the sphere. In order to enforce this constraint, new vortex rings are introduced in a manner that conserves the total momentum in the system. This models the shedding of rings from a sharp physical ridge on the sphere coincident with the circular contour. If the position of the contour is fixed on the sphere, vortex shedding is a source of drag. If the position of the contour varies periodically, propulsive rings may be shed in a manner that mimics the locomotion of certain jellyfish. We present simulations representing both cases.

  13. Man-induced hydrological changes, metazooplankton communities and invasive species in the Berre Lagoon (Mediterranean Sea, France).

    PubMed

    Delpy, Floriane; Pagano, Marc; Blanchot, Jean; Carlotti, François; Thibault-Botha, Delphine

    2012-09-01

    The Berre Lagoon has been under strong anthropogenic pressure since the early 1950s. The opening of the hydroelectric EDF power plant in 1966 led to large salinity drops. The zooplankton community was mainly composed of two common brackish species: Acartia tonsa and Brachionus plicatilis. Since 2006, European litigation has strongly constrained the input of freshwater, maintaining the salinity above 15. A study was performed between 2008 and 2010 to evaluate how these modifications have impacted the zooplankton community. Our results show that the community is more diverse and contains several coastal marine species (i.e., Centropages typicus, Paracalanus parvus and Acartia clausi). A. tonsa is still present but is less abundant, whereas B. plicatilis has completely disappeared. Strong predatory marine species, such as chaetognaths, the large conspicuous autochtonous jellyfish Aurelia aurita and the invasive ctenophore Mnemiopsis leidyi, are now very common as either seasonal or permanent features of the lagoon. PMID:22776776

  14. Induction of segmentation in polyps of Aurelia aurita (Scyphozoa, Cnidaria) into medusae and formation of mirror-image medusa anlagen.

    PubMed

    Kroiher, M; Siefker, B; Berking, S

    2000-08-01

    Polyps of Aurelia aurita can transform into several medusae (jellyfish) in a process of sequential subdivision. During this transformation, two processes take place which are well known to play a key role in the formation of various higher metazoa: segmentation and metamorphosis. In order to compare these processes in bilaterians and cnidarians we studied the control and the kinetics of these processes in Aurelia aurita. Segmentation and metamorphosis visibly start at the polyp's head and proceed down the body column but do not reach the basal disc. The small piece of polyp which remains will develop into a new polyp. The commitment to the medusa stage moves down the body column and precedes the visible onset of segmentation by about one day. Segmentation and metamorphosis can start at the cut surface of transversely cut body columns, leading to a mirror-image pattern of sequentially developing medusae. PMID:11032183

  15. Improving propulsive efficiency through passive mechanisms using a Starling vortex generator

    NASA Astrophysics Data System (ADS)

    Whittlesey, Robert; Dabiri, John

    2011-11-01

    Ruiz et al. (2011) demonstrated that pulsed propulsion with vortex rings, much like those seen in the wake of jellyfish and squid, can greatly enhance the overall efficiency of submersible vehicles. The objective of the present research is to achieve pulsed propulsion passively using a Starling vortex generator which consists of a collapsible tube within an airtight box. Recent work has shown that a Starling vortex generator is able to generate vortex rings, which indicates enhanced propulsion, while requiring less energy to generate pulsatility than the system by Ruiz et al. (2011). Current work is focused on conducting an experimental parameter study to determine an empirical scaling law suitable for design purposes, with the aim to integrate the device into a full-scale unmanned undersea vehicle. Support is greatly appreciated from ONR Awards N000140810918 and N000141010137.

  16. Locomotion gaits of a rotating cylinder pair

    NASA Astrophysics Data System (ADS)

    van Rees, Wim M.; Novati, Guido; Koumoutsakos, Petros; Mahadevan, L.

    2015-11-01

    Using 2D numerical simulations of the Navier-Stokes equations, we demonstrate that a simple pair of rotating cylinders can display a range of locomotion patterns of biological and engineering interest. Steadily counter-rotating the cylinders causes the pair to move akin to a vortex dipole for low rotation rates, but as the rotational velocity is increased the direction of motion reverses. Unsteady rotations lead to different locomotion gaits that resemble jellyfish (for in-phase rotations) and undulating swimmers (for out-of-phase rotations). The small number of parameters for this simple system allows us to systematically map the phase space of these gaits, and allows us to understand the underlying physical mechanisms using a minimal model with implications for biological locomotion and engineered analogs.

  17. The alkaloid Ageladine A, originally isolated from marine sponges, used for pH-sensitive imaging of transparent marine animals.

    PubMed

    Bickmeyer, Ulf

    2012-01-01

    The brominated pyrrole-imidazole Ageladine A was used for live imaging of the jellyfish (jellies) Nausithoe werneri, the sea anemone Metridium senile and the flatworm Macrostomum lignano. The fluorescence properties of Ageladine A allow for estimation of pH values in tissue and organs in living animals. The results showed that Nausithoe werneri had the most acidic areas in the tentacles and close to the mouth (pH 4-6.5), Metridium senile harbours aggregates of high acidity in the tentacles (pH 5) and in Macrostomum lignano, the rhabdoids, the gonads and areas close to the mouth were the most acidic with values down to pH 5. PMID:22363232

  18. The Alkaloid Ageladine A, Originally Isolated from Marine Sponges, Used for pH-Sensitive Imaging of Transparent Marine Animals

    PubMed Central

    Bickmeyer, Ulf

    2012-01-01

    The brominated pyrrole-imidazole Ageladine A was used for live imaging of the jellyfish (jellies) Nausithoe werneri, the sea anemone Metridium senile and the flatworm Macrostomum lignano. The fluorescence properties of Ageladine A allow for estimation of pH values in tissue and organs in living animals. The results showed that Nausithoe werneri had the most acidic areas in the tentacles and close to the mouth (pH 4–6.5), Metridium senile harbours aggregates of high acidity in the tentacles (pH 5) and in Macrostomum lignano, the rhabdoids, the gonads and areas close to the mouth were the most acidic with values down to pH 5. PMID:22363232

  19. A study of the possibility of sprites in the atmospheres of other planets

    NASA Astrophysics Data System (ADS)

    Yair, Yoav; Takahashi, Yukihiro; Yaniv, Roy; Ebert, Ute; Goto, Yukihiro

    2009-09-01

    Sprites are a spectacular type of transient luminous events which occur above thunderstorms immediately after lightning. They have shapes of giant jellyfish, carrots, or columns and last tens of milliseconds. In Earth's atmosphere, sprites mostly emit in red and blue wavelengths from excited N2 and N2 + and span a vertical range between 50 and 90 km above the surface. The emission spectra, morphology, and occurrence heights of sprites reflect the properties of the planetary atmosphere they inhabit and are related to the intensity of the initiating parent lightning. This paper presents results of theoretical calculations of the expected occurrence heights of sprites above lightning discharges in the CO2 atmosphere of Venus, the N2 atmosphere of Titan, and the H2-He atmosphere of Jupiter. The expected emission features are presented, and the potential of detecting sprites in planetary atmospheres by orbiting spacecraft is discussed.

  20. A genomic view of 500 million years of cnidarian evolution

    PubMed Central

    Steele, Robert E.; David, Charles N.; Technau, Ulrich

    2010-01-01

    Cnidarians (corals, anemones, jellyfish, and hydras) are a diverse group of animals of interest to evolutionary biologists, ecologists, and developmental biologists. With the publication of the genome sequences of Hydra and Nematostella, whose last common ancestor was the stem cnidarian, we are beginning to see the genomic underpinnings of cnidarian biology. Cnidarians are known for the remarkable plasticity of their morphology and life cycles. This plasticity is reflected in the Hydra and Nematostella genomes, which differ to an exceptional degree in size, base composition, transposable element content, and gene conservation. We now know what cnidarian genomes are capable of doing given 500 million years; the next challenge is to understand how this genomic history has led to the striking diversity we see in cnidarians. PMID:21047698

  1. Suction-based propulsion as a basis for efficient animal swimming

    NASA Astrophysics Data System (ADS)

    Gemmell, Brad J.; Colin, Sean P.; Costello, John H.; Dabiri, John O.

    2015-11-01

    A central and long-standing tenet in the conceptualization of animal swimming is the idea that propulsive thrust is generated by pushing the surrounding water rearward. Inherent in this perspective is the assumption that locomotion involves the generation of locally elevated pressures in the fluid to achieve the expected downstream push of the surrounding water mass. Here we show that rather than pushing against the surrounding fluid, efficient swimming animals primarily pull themselves through the water via suction. This distinction is manifested in dominant low-pressure regions generated in the fluid surrounding the animal body, which are observed by using particle image velocimetry and a pressure calculation algorithm applied to freely swimming lampreys and jellyfish. These results suggest a rethinking of the evolutionary adaptations observed in swimming animals as well as the mechanistic basis for bio-inspired and biomimetic engineered vehicles.

  2. The Role of Low-Level Jets in Regional Climate Variability and Change

    NASA Astrophysics Data System (ADS)

    Weaver, S. J.

    2015-12-01

    Low Level Jets are ubiquitous features of the global climate system. These "rivers of air" in the lower atmosphere act as a scale transfer mechanism, bridging the larger scale climate variability and change to regionally focused impacts. During the boreal spring and summer, the North American low-level jet (NALLJ) transports copious amounts of momentum, heat, and moisture into central and eastern United States, with significant impacts on regional hydroclimate variability (drought and pluvial), extreme events (tornadic activity), ecology (jellyfish and bird migration), atmospheric constituent transport (ozone), and energy development (wind power). Given the interdisciplinary importance of the NALLJ, its mean state and variability on seasonal to multidecadal timescales will be discussed in a simple framework to stimulate cross-disciplinary thought and discussion with regard to warm season regional climate variability and change.

  3. Development of Plant Gene Vectors for Tissue-Specific Expression Using GFP as a Reporter Gene

    NASA Technical Reports Server (NTRS)

    Jackson, Jacquelyn; Egnin, Marceline; Xue, Qi-Han; Prakash, C. S.

    1997-01-01

    Reporter genes are widely employed in plant molecular biology research to analyze gene expression and to identify promoters. Gus (UidA) is currently the most popular reporter gene but its detection requires a destructive assay. The use of jellyfish green fluorescent protein (GFP) gene from Aequorea Victoria holds promise for noninvasive detection of in vivo gene expression. To study how various plant promoters are expressed in sweet potato (Ipomoea batatas), we are transcriptionally fusing the intron-modified (mGFP) or synthetic (modified for codon-usage) GFP coding regions to these promoters: double cauliflower mosaic virus 35S (CaMV 35S) with AMV translational enhancer, ubiquitin7-intron-ubiquitin coding region (ubi7-intron-UQ) and sporaminA. A few of these vectors have been constructed and introduced into E. coli DH5a and Agrobacterium tumefaciens EHA105. Transient expression studies are underway using protoplast-electroporation and particle bombardment of leaf tissues.

  4. Diets of deepwater oreos (Oreosomatidae) and orange roughy Hoplostethus atlanticus.

    PubMed

    Forman, J S; Horn, P L; Stevens, D W

    2016-06-01

    The diets of black oreo Allocyttus niger, smooth oreo Pseudocyttus maculatus, spiky oreo Neocyttus rhomboidalis and orange roughy Hoplostethus atlanticus were determined from examination of contents of 240, 311, 76 and 415 non-empty stomachs, from fishes sampled by bottom trawl on Chatham Rise to the east of South Island, New Zealand. Hoplostethus atlanticus had an opportunistic predatory strategy with a broad diet dominated by prawns and mesopelagic teleosts, but with substantial components of mysids and cephalopods. Pseudocyttus maculatus was strongly specialized on gelatinous zooplankton (jellyfish and salps). Allocyttus niger consumed mainly salps and hyperiid amphipods, and to a lesser extent fishes, prawns, mysids and copepods. Neocyttus rhomboidalis primarily consumed salps, along with mysids, euphausiids and fishes. Only P. maculatus did not exhibit significant ontogenetic variation in diet. The diets were also influenced by year and bottom depth. Differences in the distributions and diets of the four species probably reduce conflicts in resource use. PMID:27188827

  5. The Late Precambrian fossil Kimberella is a mollusc-like bilaterian organism

    NASA Astrophysics Data System (ADS)

    Fedonkin, Mikhail A.; Waggoner, Benjamin M.

    1997-08-01

    The fossil Kimberella quadrata was originally described from late Precambrian rocks of southern Australia. Reconstructed as a jellyfish, it was later assigned to the cubozoans (`box jellies'), and has been cited as a clear instance of an extant animal lineage present before the Cambrian. Until recently, Kimberella was known only from Australia, with the exception of some questionable north Indian specimens. We now have over thirty-five specimens of this fossil from the Winter Coast of the White Sea in northern Russia. Our study of the new material does not support a cnidarian affinity. We reconstruct Kimberella as a bilaterally symmetrical, benthic animal with a non-mineralized, univalved shell, resembling a mollusc in many respects. This is important evidence for the existence of large triploblastic metazoans in the Precambrian and indicates that the origin of the higher groups of protostomes lies well back in the Precambrian.

  6. Mapping the Frontier Fields with Chandra X-ray Observations

    NASA Astrophysics Data System (ADS)

    Jones, Christine

    2015-08-01

    Chandra has observed both the clusters and the parallel fields in four of the Frontier Fields. These observations allow us to dramatically improve our understanding of cluster mergers through the detailed mapping of the hot cluster gas compared with high resolution mass maps and, by mapping the gas temperature and pressure, identify merger shocks. A comparison of the lensing maps and the Chandra images allows us to identify subclusters and determine if these have been stripped of their hot gas. In addition the HST images show unusual galaxies (e.g. jellyfish) whose morphologies may have resulted from interactions with the hot intracluster medium. Finally, we will report on any close pairs of AGN, which are candidates for gravitationally lensed QSOs.

  7. Proton mediated control of biochemical reactions with bioelectronic pH modulation

    PubMed Central

    Deng, Yingxin; Miyake, Takeo; Keene, Scott; Josberger, Erik E.; Rolandi, Marco

    2016-01-01

    In Nature, protons (H+) can mediate metabolic process through enzymatic reactions. Examples include glucose oxidation with glucose dehydrogenase to regulate blood glucose level, alcohol dissolution into carboxylic acid through alcohol dehydrogenase, and voltage-regulated H+ channels activating bioluminescence in firefly and jellyfish. Artificial devices that control H+ currents and H+ concentration (pH) are able to actively influence biochemical processes. Here, we demonstrate a biotransducer that monitors and actively regulates pH-responsive enzymatic reactions by monitoring and controlling the flow of H+ between PdHx contacts and solution. The present transducer records bistable pH modulation from an “enzymatic flip-flop” circuit that comprises glucose dehydrogenase and alcohol dehydrogenase. The transducer also controls bioluminescence from firefly luciferase by affecting solution pH. PMID:27052724

  8. [Land and marine fauna constituting a threat for recreational divers in the tropics].

    PubMed

    Korzeniewski, Krzysztof

    2008-09-01

    Due to intensively growing international tourism, increasing numbers of people leave for countries with hot climates, where various threats for human health and life exist. Besides climatic and sanitary conditions, a rich fauna, represented by predators and venomous animals, can be included. Based on available world literature and their own observations, the authors present the threats that a tourist can possibly encounter whilst relaxing on the beach or during recreational diving in tropical waters. When staying in water, a large threat is posed by marine fish of prey (sharks, barracuda, muraena), Cnidaria (jellyfish, corals, anemones) and venomous animals (fish, sea snakes). On land, on the other hand, a threat can be posed by venomous arthropods (scorpions, spiders) and Hymenoptera insects. The study presents the most important representatives of fauna present in coastal areas frequently visited by diving enthusiasts. Also, clinical image and conduct in the case of body injures are discussed. PMID:19112854

  9. [Accidents with venomous and poisonous animals in Central Europe].

    PubMed

    Bodio, Mauro; Junghanss, Thomas

    2009-05-01

    Central Europe is largely safe from accidents with venomous and poisonous animals. The regions where European vipers are regularly found are shrinking. Today accidents with jellyfish and stings of venomous fish afflicted during leisure activities at the sea side play the dominant role. Life threatening accidents in Europe are mainly due to exotic snakes held in captivity. A system useful in daily medical practice is explained to classify and stage accidents due to poisonous and venomous animals. The important poisonous and venomous animals of Central Europe and the specific therapeutics, the antivenoms, are covered. The antivenom depot "Antivenin-CH" of the Swiss Toxicology Information Centre in Zurich and the MRITox in Munich with the antivenom registry Munich AntiVenom INdex (MAVIN) are presented. PMID:19401985

  10. Hydrodynamics of Peristaltic Propulsion

    NASA Astrophysics Data System (ADS)

    Athanassiadis, Athanasios; Hart, Douglas

    2014-11-01

    A curious class of animals called salps live in marine environments and self-propel by ejecting vortex rings much like jellyfish and squid. However, unlike other jetting creatures that siphon and eject water from one side of their body, salps produce vortex rings by pumping water through siphons on opposite ends of their hollow cylindrical bodies. In the simplest cases, it seems like some species of salp can successfully move by contracting just two siphons connected by an elastic body. When thought of as a chain of timed contractions, salp propulsion is reminiscent of peristaltic pumping applied to marine locomotion. Inspired by salps, we investigate the hydrodynamics of peristaltic propulsion, focusing on the scaling relationships that determine flow rate, thrust production, and energy usage in a model system. We discuss possible actuation methods for a model peristaltic vehicle, considering both the material and geometrical requirements for such a system.

  11. Evolution of multicellular animals as deduced from 5S rRNA sequences: a possible early emergence of the Mesozoa.

    PubMed

    Ohama, T; Kumazaki, T; Hori, H; Osawa, S

    1984-06-25

    The nucleotide sequences of 5S rRNA from a mesozoan Dicyema misakiense and three metazoan species, i.e., an acorn-worm Saccoglossus kowalevskii, a moss-animal Bugula neritina, and an octopus Octopus vulgaris have been determined. A phylogenic tree of multicellular animals has been constructed from 73 5S rRNA sequences available at present including those from the above four sequences. The tree suggests that the mesozoan is the most ancient multicellular animal identified so far, its emergence time being almost the same as that of flagellated or ciliated protozoans. The branching points of planarians and nematodes are a little later than that of the mesozoan but are clearly earlier than other metazoan groups including sponges and jellyfishes. Many metazoan groups seem to have diverged within a relatively short period. PMID:6539911

  12. Mini-review: the evolution of neuropeptide signaling.

    PubMed

    Grimmelikhuijzen, Cornelis J P; Hauser, Frank

    2012-08-10

    Neuropeptides and their G protein-coupled receptors (GPCRs) have an early evolutionary origin and are already abundant in basal animals with primitive nervous systems such as cnidarians (Hydra, jellyfishes, corals, and sea anemones). Most animals emerging after the Cnidaria belong to two evolutionary lineages, the Protostomia (to which the majority of invertebrates belong) and Deuterostomia (to which some minor groups of invertebrates, and all vertebrates belong). These two lineages split about 700 million years (Myr) ago. Many mammalian neuropeptide GPCRs have orthologues in the Protostomia and this is also true for some of the mammalian neuropeptides. Examples are oxytocin/vasopressin, GnRH, gastrin/CCK, and neuropeptide Y and their GPCRs. These results implicate that protostomes (for example insects and nematodes) can be used as models to study the biology of neuropeptide signaling. PMID:22726357

  13. Antispasmodic activity of beta-damascenone and E-phytol isolated from Ipomoea pes-caprae.

    PubMed

    Pongprayoon, U; Baeckström, P; Jacobsson, U; Lindström, M; Bohlin, L

    1992-02-01

    The crude extract (IPA) of the plant Ipomoea pes-caprae (L.) R. Br. has previously been shown to antagonize smooth muscle contractions induced by several agonists via a non-specific mechanism. Bioassay-guided fractionation of IPA resulted in isolation of the antispasmodically acting isoprenoids beta-damascenone and E-phytol. Their antispasmodic potencies were found to be in the same range as that of papaverine, a general spasmolytic agent. This effect was suggested to play a role in the previously observed anti-inflammatory activity of IPA by interfering with the contraction of endothelial cells. Severe vascular contraction has been shown to be involved in the dermatitis caused by toxic jellyfishes. It is possible that beta-damascenone and E-phytol, by interfering with the contraction of vascular smooth muscle cells, are partly responsible for the previously reported effectiveness of IPA in the treatment of such dermatitis. PMID:1620738

  14. Multispecies impingement in a tropical power plant, Straits of Malacca.

    PubMed

    Azila, A; Chong, V C

    2010-07-01

    Marine organisms comprised about 70% of the total impinged materials by weight at water intake screens in the Kapar Power Station (KPS), Malaysia. The general groupings of 'fish', 'shrimp', 'crab', 'cephalopod' and 'others' contributed 26% (87 species), 65% (29), 2% (17), 2% (3) and 5% (42) of the total number of impinged organisms, respectively. In general, higher impingement occurred during spring tide, at nighttime and in shallow water. The glass perchlet, anchovies, ponyfishes, mojarra, catfishes, hairtail, scat and young croakers were the most vulnerable fishes. Vulnerable invertebrates included cephalopods, sea urchin, rockshells and jellyfishes, but penaeid shrimps were the most susceptible in terms of both mortality and body injury. Annually, KPS is estimated to kill 8.5 x 10(6) marine organisms (42 tons) by impingement. This amount, however, is minimal compared to commercial fishery harvests. Multispecies impingement at Malaysian power plants poses the problem of finding the best mitigation options for tropical situations. PMID:20338631

  15. Spacelab Life Sciences 1 - The stepping stone

    NASA Technical Reports Server (NTRS)

    Dalton, B. P.; Leon, H.; Hogan, R.; Clarke, B.; Tollinger, D.

    1988-01-01

    The Spacelab Life Sciences (SLS-1) mission scheduled for launch in March 1990 will study the effects of microgravity on physiological parameters of humans and animals. The data obtained will guide equipment design, performance of activities involving the use of animals, and prediction of human physiological responses during long-term microgravity exposure. The experiments planned for the SLS-1 mission include a particulate-containment demonstration test, integrated rodent experiments, jellyfish experiments, and validation of the small-mass measuring instrument. The design and operation of the Research Animal Holding Facility, General-Purpose Work Station, General-Purpose Transfer Unit, and Animal Enclosure Module are discussed and illustrated with drawings and diagrams.

  16. Density regulation in Sarsia tubulosa (Hydrozoa)

    NASA Astrophysics Data System (ADS)

    Leonard, J. L.

    1980-03-01

    The majority of wild-caught Sarsia tubulosa M. Sars medusae are less dense than the surrounding water. The bell of S. tubulosa is the buoyant structure; the tentacles and manubrium sink if cut off from the bell. S. tubulosa individuals placed in dilute seawater sink initially but recover positive or neutral buoyancy and normal activity within a couple of hours. In all cases observed animals were able to achieve positive buoyancy in seawater of 20.25 ‰ S and some individuals were able to adjust to lower salinities. In most cases where positive buoyancy was not attained within two hours the animal did not achieve positive buoyancy within twelve hours and died within that period. While the mechanism of regulation is not known, ionic pumping, possibly involving the extrusion of sulphate ion, has been suggested to be responsible for the buoyancy of mesoglea in other jellyfishes.

  17. [Aquatic animals of medical importance in Brazil].

    PubMed

    Haddad Junior, Vidal

    2003-01-01

    The injuries caused by venomous and poisonous aquatic animals may provoke important morbidity in the victim. The cnidarians (jellyfishes, especially cubomedusas and Portuguese-Man-of-War) caused nearly 25% of 236 accidents by marine animals, while sea urchins were responsible for about 50% and catfish, stingrays and scorpionfish nearly 25%). In freshwater, stingrays and catfish cause injuries with a very similar mechanism to the poisoning and the effects of the toxins of marine species. In a series of about 200 injuries observed among freshwater fishermen, nearly 40% were caused by freshwater catfish, 5% freshwater stingrays and 55% by traumatogenic fish, such as piranhas and traíras. The author presents the aquatic animals that cause injuries to humans in Brazil, the clinical aspects of the envenoming and the first measures for the control of the severe pain observed mainly in the accidents caused by cnidarians and venomous fishes. PMID:14576874

  18. Life Cycle Reversal in Aurelia sp.1 (Cnidaria, Scyphozoa)

    PubMed Central

    He, Jinru; Zheng, Lianming; Zhang, Wenjing; Lin, Yuanshao

    2015-01-01

    The genus Aurelia is one of the major contributors to jellyfish blooms in coastal waters, possibly due in part to hydroclimatic and anthropogenic causes, as well as their highly adaptive reproductive traits. Despite the wide plasticity of cnidarian life cycles, especially those recognized in certain Hydroza species, the known modifications of Aurelia life history were mostly restricted to its polyp stage. In this study, we document the formation of polyps directly from the ectoderm of degenerating juvenile medusae, cell masses from medusa tissue fragments, and subumbrella of living medusae. This is the first evidence for back-transformation of sexually mature medusae into polyps in Aurelia sp.1. The resulting reconstruction of the schematic life cycle of Aurelia reveals the underestimated potential of life cycle reversal in scyphozoan medusae, with possible implications for biological and ecological studies. PMID:26690755

  19. [Medical aspects of diving in the tropics].

    PubMed

    Muth, C M; Müller, P; Kemmer, A

    2005-07-01

    Scuba diving vacations in tropical surroundings belong to the repertoire of most divers. In addition to carefully making travel plans and taking care of the necessary vaccinations and appropriate malaria prophylaxis, the following points also must be observed. The flight itself affects diving safety. In particular, a too short time interval between diving and the return flight can lead to decompression problems. Because most of the diving areas are reached by ship, many divers need a prophylaxis against motion sickness. Moreover, external otitis occurs more frequently while diving in the tropics. Finally, there is potential danger from the sea inhabitants, primarily from scorpion fishes, Portuguese Man-of-Wars, box jellyfishes as well as cone snails. PMID:16041936

  20. Impact of secondary hard substrate on the distribution and abundance of Aurelia aurita in the western Baltic Sea.

    PubMed

    Janßen, H; Augustin, C B; Hinrichsen, H H; Kube, S

    2013-10-15

    This study assessed the impact of secondary hard substrate, as being introduced into marine ecosystems by the establishment of wind farm pillars, on the occurrence and distribution of the moon jelly Aurelia aurita in the southwestern Baltic Sea. A two-year data sampling was conducted with removable settlement plates to assess the distribution and population development of the scyphozoan polyps. The data collected from these samples were used to set up a model with Lagrangian particle technique. The results confirm that anthropogenic created hard substrate (e.g. offshore wind farms) has the potential to increase the abundance of the A. aurita population. The distribution of wind farm borne jellyfish along Danish, German and Polish coasts indicates conflicts with further sectors, mainly energy and tourism. PMID:23987093

  1. Marine debris ingestion and Thayer's law - The importance of plastic color.

    PubMed

    Santos, Robson G; Andrades, Ryan; Fardim, Lorena M; Martins, Agnaldo Silva

    2016-07-01

    In recent years marine plastic pollution has gained considerable attention as a significant threat to marine animals. Despite the abundant literature related to marine debris ingestion, only a few studies attempted to understand the factors involved in debris ingestion. Plastic ingestion is commonly attributed to visual similarities of plastic fragments to animal's prey items, such as plastic bags and jellyfish. However, this simple explanation is not always coherent with the variety of debris items ingested and with the species' main prey items. We assess differences in the conspicuousness of plastic debris related to their color using Thayer's law to infer the likelihood that visual foragers detect plastic fragments. We hypothesize that marine animals that perceive floating plastic from below should preferentially ingest dark plastic fragments, whereas animals that perceive floating plastic from above should select for paler plastic fragments. PMID:27131818

  2. Integrated trend assessment of ecosystem changes in the Limfjord (Denmark): Evidence of a recent regime shift?

    NASA Astrophysics Data System (ADS)

    Tomczak, Maciej T.; Dinesen, Grete E.; Hoffmann, Erik; Maar, Marie; Støttrup, Josianne G.

    2013-01-01

    An integrated ecosystem assessment was carried out for the Limfjord over the period from 1984 to 2008 to describe changes in ecosystem structure and potentially important drivers. The Limfjord is a eutrophic transitional Danish fjord system with the main inflow from the North Sea in the west and main outflow to the Kattegat in the east. We showed that from 1990 to 1995, the ecosystem structure shifted from dominance by demersal fish species (eelpout, whiting, flounder, plaice) to that of pelagic fish species (sprat, herring, sticklebacks), small-bodied fish species (black goby, pipefish), jellyfish, common shore crab, starfish and blue mussels. We interpret this change as a regime shift that showed a similar temporal pattern to regime shifts identified in adjacent seas. The observed changes in trophic interactions and food web reorganisation suggested a non-linear regime shift. The analyses further showed the regime shift to be driven by a combination of anthropogenic pressures and possible interplay with climatic disturbance.

  3. Occupational health issues in marine and freshwater research

    PubMed Central

    2012-01-01

    Marine and freshwater scientists are potentially exposed to a wide variety of occupational hazards. Depending on the focus of their research, risks may include animal attacks, physiological stresses, exposure to toxins and carcinogens, and dangerous environmental conditions. Many of these hazards have been investigated amongst the general population in their recreational use of the environment; however, very few studies have specifically related potential hazards to occupational exposure. For example, while the incidence of shark and crocodile attacks may invoke strong emotions and the occupational risk of working with these animals is certainly real, many more people are stung by jellyfish or bitten by snakes or dogs each year. Furthermore, a large proportion of SCUBA-related injuries and deaths are incurred by novice or uncertified divers, rather than professional divers using aquatic environments. Nonetheless, marine and freshwater research remains a potentially risky occupation, and the likelihood of death, injury and long-term health impacts still needs to be seriously considered. PMID:22429712

  4. Aquatic dermatology: encounters with the denizens of the deep (and not so deep) a review. Part I: the invertebrates.

    PubMed

    Ottuso, Patrick

    2013-02-01

    Aquatic dermatoses encompass a broad spectrum of cutaneous injuries. These injuries may present through contact with invertebrate organisms such as jellyfish, sea urchins, corals, and molluscs. Each organism is equipped with a unique method of causing harm to man, therefore a myriad of presenting signs and symptoms should be recognized in order to initiate treatment. Aquatic injuries are not limited to areas of the world where these species originate. With the advent of rapid world travel and the hobby of home aquariums, dermatologists play a key role in the early diagnosis and treatment of such injuries. The method of injury, including a discussion of organism identification will be presented. Additionally, treatment of injuries caused by aquatic life will follow. PMID:23347300

  5. Suction-based propulsion as a basis for efficient animal swimming

    PubMed Central

    Gemmell, Brad J.; Colin, Sean P.; Costello, John H.; Dabiri, John O.

    2015-01-01

    A central and long-standing tenet in the conceptualization of animal swimming is the idea that propulsive thrust is generated by pushing the surrounding water rearward. Inherent in this perspective is the assumption that locomotion involves the generation of locally elevated pressures in the fluid to achieve the expected downstream push of the surrounding water mass. Here we show that rather than pushing against the surrounding fluid, efficient swimming animals primarily pull themselves through the water via suction. This distinction is manifested in dominant low-pressure regions generated in the fluid surrounding the animal body, which are observed by using particle image velocimetry and a pressure calculation algorithm applied to freely swimming lampreys and jellyfish. These results suggest a rethinking of the evolutionary adaptations observed in swimming animals as well as the mechanistic basis for bio-inspired and biomimetic engineered vehicles. PMID:26529342

  6. New tricks with old genes: the genetic bases of novel cnidarian traits.

    PubMed

    Forêt, Sylvain; Knack, Brent; Houliston, Evelyn; Momose, Tsuyoshi; Manuel, Michael; Quéinnec, Eric; Hayward, David C; Ball, Eldon E; Miller, David J

    2010-04-01

    Recent thought on genome evolution has focused on the creation of new genes and changes in regulatory mechanisms while ignoring the role of selective gene loss in shaping genomes. Using data from two cnidarians, the jellyfish Clytia and the coral Acropora, we examined the relative significance of new 'taxonomically restricted' genes and selectively retained ancestral genes in enabling the evolution of novel traits. Consistent with its more complex life-cycle, the proportion of novel genes identified in Clytia was higher than that in the 'polyp only' cnidarians Nematostella and Hydra, but each of these cnidarians has retained a proportion of ancestral genes not present in the other two. The ubiquity and near-stochastic nature of gene loss can explain the discord between patterns of gene distribution and taxonomy. PMID:20129693

  7. First Ground-based Observation of Transient Luminous Events over Southern Africa

    NASA Astrophysics Data System (ADS)

    Nnadih, Ogechukwu; Kosch, Michael; Martinez, Peter

    2016-07-01

    We present the first ground-based observations in southern Africa of Transient Luminous Events (TLEs) in the summer of 2015/16 over convective thunderstorms. For the months of December to February, South Africa has one of the highest lightning stroke rates in the world. This was part of the AfriSprite campaign initiated by the South African National Space Agency. These observations show a variety of fine structures such as tree-like shaped, carrot, angel and jellyfish-shaped sprites. The South African Weather Service array of VLF receivers is used to locate and quantify the magnitude and polarity of the lightning strikes associated with TLEs. We plan to make bi-static as well as multi-wavelength observations in future.

  8. A Darwinian mechanism for biogenic ocean mixing

    NASA Astrophysics Data System (ADS)

    Katija, Kakani; Dabiri, John

    2009-11-01

    Recent observations of biogenic turbulence in the ocean have led to conflicting ideas regarding the contribution of animal swimming to ocean mixing. Previous measurements indicate elevated turbulent dissipation in the vicinity of large populations of planktonic animals swimming in concert. However, elevated turbulent dissipation is by itself insufficient proof of substantial biogenic mixing. We conducted field measurements of mixing efficiency by individual Mastigias sp. (a Palauan jellyfish) using a self-contained underwater velocimetry apparatus. These measurements revealed another mechanism that contributes to animal mixing besides wake turbulence. This mechanism was first described by Sir Charles Galton Darwin and is in fact the dominant mechanism of mixing by swimming animals. The efficiency of Darwin's mechanism (or drift) is dependent on animal shape rather than fluid length scale and, unlike turbulent wake mixing, is enhanced by the fluid viscosity. Therefore, it provides a means of biogenic mixing that can be equally effective in small plankton and large mammals.

  9. Brain Ways: Meynert, Bachelard and the Material Imagination of the Inner Life.

    PubMed

    Phelps, Scott

    2016-07-01

    The Austrian psychiatrist Theodor Meynert's anatomical theories of the brain and nerves are laden with metaphorical imagery, ranging from the colonies of empire to the tentacles of jellyfish. This paper analyses among Meynert's earliest works a different set of less obvious metaphors, namely, the fibres, threads, branches and paths used to elaborate the brain's interior. I argue that these metaphors of material, or what the philosopher Gaston Bachelard called 'material images', helped Meynert not only to imaginatively extend the tracts of fibrous tissue inside the brain but to insinuate their function as pathways co-extensive with the mind. Above all, with reference to Bachelard's study of the material imagination, I argue that Meynert helped entrench the historical intuition that the mind, whatever it was, consisted of some interiority - one which came to be increasingly articulated through the fibrous confines of the brain. PMID:27292326

  10. Observation of Marine Animals Using Underwater Acoustic Camera

    NASA Astrophysics Data System (ADS)

    Iida, Kohji; Takahashi, Rika; Tang, Yong; Mukai, Tohru; Sato, Masanori

    2006-05-01

    An underwater acoustic camera enclosed in a pressure-resistant case was constructed to observe underwater marine animals. This enabled the measurement of the size, shape, and behavior of living marine animals in the detection range up to 240 cm. The transducer array of the acoustic camera was driven by 3.5 MHz ultrasonic signals, and B-mode acoustic images were obtained. Observations were conducted for captive animals in a water tank and for natural animals in a field. The captive animals, including fish, squid and jellyfish, were observed, and a three-dimensional internal structure of animals was reconstructed using multiple acoustical images. The most important contributors of acoustic scattering were the swimbladder and vertebra of bladdered fish, and the liver and reproductive organs of invertebrate animals. In a field experiment, the shape, size, and swimming behavior of wild animals were observed. The possibilities and limitations of the underwater acoustic camera for fishery applications were discussed.

  11. Proton mediated control of biochemical reactions with bioelectronic pH modulation

    NASA Astrophysics Data System (ADS)

    Deng, Yingxin; Miyake, Takeo; Keene, Scott; Josberger, Erik E.; Rolandi, Marco

    2016-04-01

    In Nature, protons (H+) can mediate metabolic process through enzymatic reactions. Examples include glucose oxidation with glucose dehydrogenase to regulate blood glucose level, alcohol dissolution into carboxylic acid through alcohol dehydrogenase, and voltage-regulated H+ channels activating bioluminescence in firefly and jellyfish. Artificial devices that control H+ currents and H+ concentration (pH) are able to actively influence biochemical processes. Here, we demonstrate a biotransducer that monitors and actively regulates pH-responsive enzymatic reactions by monitoring and controlling the flow of H+ between PdHx contacts and solution. The present transducer records bistable pH modulation from an “enzymatic flip-flop” circuit that comprises glucose dehydrogenase and alcohol dehydrogenase. The transducer also controls bioluminescence from firefly luciferase by affecting solution pH.

  12. Proton mediated control of biochemical reactions with bioelectronic pH modulation

    DOE PAGESBeta

    Deng, Yingxin; Miyake, Takeo; Keene, Scott; Josberger, Erik E.; Rolandi, Marco

    2016-04-07

    In Nature, protons (H+) can mediate metabolic process through enzymatic reactions. Examples include glucose oxidation with glucose dehydrogenase to regulate blood glucose level, alcohol dissolution into carboxylic acid through alcohol dehydrogenase, and voltage-regulated H+ channels activating bioluminescence in firefly and jellyfish. Artificial devices that control H+ currents and H+ concentration (pH) are able to actively influence biochemical processes. Here, we demonstrate a biotransducer that monitors and actively regulates pH-responsive enzymatic reactions by monitoring and controlling the flow of H+ between PdHx contacts and solution. The present transducer records bistable pH modulation from an “enzymatic flip-flop” circuit that comprises glucose dehydrogenasemore » and alcohol dehydrogenase. Furthermore, the transducer also controls bioluminescence from firefly luciferase by affecting solution pH.« less

  13. Role of Coherent Low-Frequency Motion in Excited-State Proton Transfer of Green Fluorescent Protein Studied by Time-Resolved Impulsive Stimulated Raman Spectroscopy.

    PubMed

    Fujisawa, Tomotsumi; Kuramochi, Hikaru; Hosoi, Haruko; Takeuchi, Satoshi; Tahara, Tahei

    2016-03-30

    Green fluorescent protein (GFP) from jellyfish Aequorea victoria, an essential bioimaging tool, luminesces via excited-state proton transfer (ESPT) in which the phenolic proton of the p-hydroxybenzylideneimidazolinone chromophore is transferred to Glu222 through a hydrogen-bond network. In this process, the ESPT mediated by the low-frequency motion of the chromophore has been proposed. We address this issue using femtosecond time-resolved impulsive stimulated Raman spectroscopy. After coherently exciting low-frequency modes (<300 cm(-1)) in the excited state of GFP, we examined the excited-state structural evolution and the ESPT dynamics within the dephasing time of the low-frequency vibration. A clear anharmonic vibrational coupling is found between one high-frequency mode of the chromophore (phenolic CH bend) and a low-frequency mode at ∼104 cm(-1). However, the data show that this low-frequency motion does not substantially affect the ESPT dynamics. PMID:26943852

  14. A salp bloom (Tunicata, Thaliacea) along the Apulian coast and in the Otranto Channel between March-May 2013.

    PubMed

    Boero, Ferdinando; Belmonte, Genuario; Bracale, Roberta; Fraschetti, Simonetta; Piraino, Stefano; Zampardi, Serena

    2013-01-01

    Between March-May 2013 a massive Salpa maxima bloom was recorded by a citizen science study along the Ionian and Adriatic coast of the Salento peninsula (Italy). Citizen records were substantiated with field inspections along the coast and during an oceanographic campaign in the Otranto Channel. Salps clogged nets, impairing fishing activities along the coast. Swimmers were scared by the gelatinous appearance of the salps, and thought they were jellyfish. At the end of the bloom the dead bodies of the colonies, that were up to 6-7 m long, were accumulated along the coast and stirred by the waves, forming foams along dozens of kilometers of coast. The bloom also occurred at the Tremiti Islands, north of the Gargano Peninsula. The possible impacts of such events on the  functioning of pelagic systems are discussed. PMID:26594319

  15. A Lagrangian approach to vortex identification in swimming and flying animal wakes.

    NASA Astrophysics Data System (ADS)

    Peng, Jifeng; Dabiri, John

    2006-11-01

    The fluid wakes of swimming and flying animals are generally time-dependent. The Eulerian velocity field, which can be measured by existing DPIV measurement techniques, does not directly indicate the flow geometry in this type of unsteady flows. In this study, a Lagrangian approach is developed to determine the Lagrangian Coherent Structures, which are physical boundaries separating flow regions with distinct dynamics, including vortices. The determination of morphology and kinematics of vortices is necessary in estimating time-dependent locomotive forces (Dabiri, J. Exp. Bio., 2006). It also provides information in studying fluid transport in animal swimming and flying. The application of the method is demonstrated by studying the wake of a bluegill sunfish pectoral fin and that of a free-swimming jellyfish.

  16. A vorticity-free approach to wake-based swimming/flying force estimation

    NASA Astrophysics Data System (ADS)

    Dabiri, John O.; Peng, Jifeng

    2006-11-01

    Traditional wake-based analyses of animal swimming and flying depend largely on knowledge of the vorticity field, which can be difficult or impossible to incorporate in the context of unsteady fluid-structure interactions. This talk will describe the development and application of a technique for estimating swimming/flying forces that does not require measurement of the vorticity field. The method is based on the identification of Lagrangian Coherent Structures in the wake, whose dynamics are governed by the theory for deformable bodies in potential flow (Peng and Dabiri, J. Exp. Biol. 2007). This paradigm for the analysis of unsteady fluid-structure interactions is integrated with existing DPIV measurement techniques to analyze medusan (jellyfish) swimming and the dynamics of the bluegill sunfish pectoral fin.

  17. Brain Ways: Meynert, Bachelard and the Material Imagination of the Inner Life

    PubMed Central

    Phelps, Scott

    2016-01-01

    The Austrian psychiatrist Theodor Meynert’s anatomical theories of the brain and nerves are laden with metaphorical imagery, ranging from the colonies of empire to the tentacles of jellyfish. This paper analyses among Meynert’s earliest works a different set of less obvious metaphors, namely, the fibres, threads, branches and paths used to elaborate the brain’s interior. I argue that these metaphors of material, or what the philosopher Gaston Bachelard called ‘material images’, helped Meynert not only to imaginatively extend the tracts of fibrous tissue inside the brain but to insinuate their function as pathways co-extensive with the mind. Above all, with reference to Bachelard’s study of the material imagination, I argue that Meynert helped entrench the historical intuition that the mind, whatever it was, consisted of some interiority – one which came to be increasingly articulated through the fibrous confines of the brain. PMID:27292326

  18. Marine debris ingestion by Chelonia mydas (Testudines: Cheloniidae) on the Brazilian coast.

    PubMed

    da Silva Mendes, Sarah; de Carvalho, Robson Henrique; de Faria, Adriana Fonseca; de Sousa, Bernadete Maria

    2015-03-15

    Chelonia mydas is distributed in several regions of the world and they are common in coastal regions and around islands. Between August 2008 and July 2009, 20 specimens of C. mydas were found dead on the beaches of Ubatuba, São Paulo, Brazil. The stomachs were removed and anthropogenic wastes were separated according their malleability and color. Of those animals, nine had ingested marine debris. Soft plastic was the most frequent among the samples and the majority of fragments was white or colorless and was between zero and five cm. Many studies have shown a high incidence of eating waste for some species of sea turtles. The record of ingestion of mostly transparent and white anthropogenic wastes in this study strengthens the hypothesis that these animals mistake them for jellyfish. Although the intake of anthropogenic waste causes impact on the lives of sea turtles, such studies are still scarce in Brazil. PMID:25638049

  19. Factors affecting toxicity test endpoints in sensitive life stages of native Gulf of Mexico species.

    PubMed

    Echols, B S; Smith, A J; Rand, G M; Seda, B C

    2015-05-01

    Indigenous species are less commonly used in laboratory aquatic toxicity tests compared with standard test species due to (1) limited availability lack of requisite information necessary for their acclimation and maintenance under laboratory conditions and (2) lack of information on their sensitivity and the reproducibility of toxicity test results. As part of the Natural Resource Damage Assessment aquatic toxicity program in response to the Deepwater Horizon Oil incident (2010), sensitive life stages of native Gulf of Mexico species were evaluated in laboratory toxicity tests to determine the potential effects of the spill. Fish (n = 5) and invertebrates (n = 2) selected for this program include the following: the Florida pompano (Trachinotus carolinus), red drum (Sciaenops ocellatus), spotted sea trout (Cynoscion nebulosus), cobia (Rachycentron canadum), red porgy (Pagrus pagrus), blue crab (Callinectes sapidus), and the common moon jellyfish (Aurelia aurita). Initially in the program, to establish part of the background information, acute tests with reference toxicants (CdCl2, KCl, CuSO4) were performed with each species to establish data on intraspecies variability and test precision as well as identify other factors that may affect toxicity results. Median lethal concentration (LC50) values were calculated for each acute toxicity test with average LC50 values ranging from 248 to 862 mg/L for fish exposures to potassium chloride. Variability between test results was determined for each species by calculating the coefficient of variation (%CV) based on LC50 values. CVs ranged from 11.2 % for pompano (96-h LC50 value) to 74.8 % for red porgy 24-h tests. Cadmium chloride acute toxicity tests with the jellyfish A. aurita had the lowest overall CV of 3.6 %. By understanding acute toxicity to these native organisms from a compound with known toxicity ranges and the variability in test results, acute tests with nonstandard species can be better interpreted and used

  20. Mortality of discards from southeastern Australian beach seines and gillnets.

    PubMed

    Broadhurst, Matt K; Millar, Russell B; Brand, Craig P; Uhlmann, Sebastian S

    2008-06-19

    Two experiments were done in an Australian estuary to quantify the mortalities and contributing factors for key species discarded during 8 and 9 deployments of commercial beach (or shore) seines and gillnets, respectively. In both experiments, bycatches (2347 individuals comprising 16 species) were handled according to conventional practices and assessed for immediate mortalities before live samples of selected species were discarded into replicate cages along with appropriate controls, and monitored for short-term mortalities (< or =10 d). All of the seined or gilled fish were alive prior to discarding. During the beach seine experiment, 20% of caged seined-and-discarded surf bream Acanthopagrus australis (n = 290) were dead after 5 d, with most mortalities occurring between the second and fifth day. In the gillnet experiment, 42 and 11% of gilled-and-discarded A. australis (n = 161) and lesser salmon catfish Neoarius graeffei (n = 67), respectively, died during a 10 d monitoring period, mostly within the first 5 d. There were no deaths in any controls for these fish. Mixed-effects logistic models revealed that the mortality of A. australis discarded from both gears was significantly (p < 0.01) and negatively correlated with their total length, while N. graeffei had a significantly (p < 0.05) greater (5-fold) probability of dying when jellyfish Catostylus sp. were present in the gillnet. Simple modifications to the operations of beach seines and gillnets and/or post-capture handling procedures, such as close regulation of size selectivity for the target species, careful removal of fish from meshes, and abstention from setting during high abundances of jellyfish will maximise the survival of discarded bycatch. PMID:18714684