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Sample records for jellyfish cyanea nozakii

  1. 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.

  2. 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.

  3. Functional Elucidation of Nemopilema nomurai and Cyanea nozakii Nematocyst Venoms’ Lytic Activity Using Mass Spectrometry and Zymography

    PubMed Central

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

    2017-01-01

    Background: Medusozoans utilize explosively discharging penetrant nematocysts to inject venom into prey. These venoms are composed of highly complex proteins and peptides with extensive bioactivities, as observed in vitro. Diverse enzymatic toxins have been putatively identified in the venom of jellyfish, Nemopilema nomurai and Cyanea nozakii, through examination of their proteomes and transcriptomes. However, functional examination of putative enzymatic components identified in proteomic approaches to elucidate potential bioactivities is critically needed. Methods: In this study, enzymatic toxins were functionally identified using a combined approach consisting of in gel zymography and liquid chromatography tandem mass spectrometry (LC-MS/MS). The potential roles of metalloproteinases and lipases in hemolytic activity were explored using specific inhibitors. Results: Zymography indicated that nematocyst venom possessed protease-, lipase- and hyaluronidase-class activities. Further, proteomic approaches using LC-MS/MS indicated sequence homology of proteolytic bands observed in zymography to extant zinc metalloproteinase-disintegrins and astacin metalloproteinases. Moreover, pre-incubation of the metalloproteinase inhibitor batimastat with N. nomurai nematocyst venom resulted in an approximate 62% reduction of hemolysis compared to venom exposed sheep erythrocytes, suggesting that metalloproteinases contribute to hemolytic activity. Additionally, species within the molecular mass range of 14–18 kDa exhibited both egg yolk and erythrocyte lytic activities in gel overlay assays. Conclusion: For the first time, our findings demonstrate the contribution of jellyfish venom metalloproteinase and suggest the involvement of lipase species to hemolytic activity. Investigations of this relationship will facilitate a better understanding of the constituents and toxicity of jellyfish venom. PMID:28134758

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. Physiological and chemical analysis of neurotransmitter candidates at a fast excitatory synapse in the jellyfish Cyanea capillata (Cnidaria, Scyphozoa).

    PubMed

    Anderson, Peter A V; Trapido-Rosenthal, H G

    2009-12-01

    Motor nerve net (MNN) neurons in the jellyfish Cyanea capillata communicate with one another by way of fast, bidirectional excitatory chemical synapses. As is the case with almost all identified chemical synapses in cnidarians, the identity of the neurotransmitter at these synapses is unclear. MNN neurons are large enough for stable intracellular recordings. This, together with the fact that they can be exposed, providing unlimited access to them and to their synapses, prompted a study of the action of a variety of neurotransmitter candidates, including those typically associated with fast synapses in higher animals. Only the amino acids taurine and beta-alanine produced physiological responses consistent with those of the normal EPSP in these cells. Moreover, chemical analysis revealed that both taurine and beta-alanine are present in the neurons and released by depolarization. These various findings strongly suggest that either or both of these amino acids, or a closely related compound is the neurotransmitter at the fast chemical synapses between MNN neurons.

  9. 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

  10. 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

  11. 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.

  12. First report of a peroxiredoxin homologue in jellyfish: molecular cloning, expression and functional characterization of CcPrx4 from Cyanea capillata.

    PubMed

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

    2014-01-09

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

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

    PubMed Central

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

    2014-01-01

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

  14. First report of a thioredoxin homologue in jellyfish: molecular cloning, expression and antioxidant activity of CcTrx1 from Cyanea capillata.

    PubMed

    Ruan, Zengliang; Liu, Guoyan; Guo, Yufeng; Zhou, Yonghong; Wang, Qianqian; Chang, Yinlong; Wang, Beilei; Zheng, Jiemin; Zhang, Liming

    2014-01-01

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

  15. Mitochondrial dysfunction contributes to the cytotoxicity induced by tentacle extract from the jellyfish Cyanea capillata in rat renal tubular epithelial NRK-52E cells.

    PubMed

    Wang, Tao; He, Qian; Xiao, Liang; Wang, Qianqian; Zhang, Bo; Wang, Beilei; Liu, Guoyan; Zheng, Jiemin; Yu, Bentong; Zhang, Liming

    2013-11-01

    Our previous studies have shown that tentacle extract (TE) from the jellyfish Cyanea capillata could induce a delayed jellyfish envenomation syndrome with severe multiple organ dysfunctions, among which renal injury with tubular necrosis seemed to be most serious. So, in this study, we aimed to explore the toxic effect of TE on rat renal tubular epithelial NRK-52E cells. Based on the previous findings that TE could cause oxidative damage in erythrocytes, the effects of TE on cell oxidative stress conditions, including ROS production and lipid peroxidation, and mitochondrial dysfunction associated with cell death were investigated in NRK-52E cells. The results showed that TE caused cell morphological change and decreased cell viability through induction of apoptosis and necrosis in NRK-52E cells. Meanwhile, ROS overproduction and mitochondrial membrane potential decrease were found before the cell death occurred. It was concluded that TE could induce cytotoxicity, especially apoptosis and necrosis, in NRK-52E cells, and mitochondrial dysfunction and ROS overproduction might play important roles in the process of cell injury and death.

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

    PubMed

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

    2013-03-01

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

  17. 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.

  18. 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

  19. 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

  20. Morphology and phylogeny of a new wall-less freshwater volvocalean flagellate, Hapalochloris nozakii gen. et sp. nov. (Volvocales, Chlorophyceae).

    PubMed

    Nakada, Takashi; Tomita, Masaru

    2016-10-21

    New strains of a wall-less unicellular volvocalean flagellate were isolated from a freshwater environment in Japan. Observations of the alga, described here as Hapalochloris nozakii Nakada, gen. et sp. nov., were made using light, fluorescence, and electron microscopy. Each vegetative cell had two flagella, four contractile vacuoles, and a spirally furrowed cup-shaped chloroplast with an axial pyrenoid, and mitochondria located in the furrows. Based on the morphology, H. nozakii was distinguished from other known wall-less volvocalean flagellates. Under electron microscopy, fibrous material, instead of a cell wall and dense cortical microtubules, was observed outside and inside the cell membrane, respectively. Based on the phylogenetic analyses of 18S rRNA gene sequences, H. nozakii was found to be closely related to Asterococcus, Oogamochlamys, Rhysamphichloris, and "Dunaliella" lateralis and was separated from other known wall-less flagellate volvocaleans, indicating independent secondary loss of the cell wall in H. nozakii. In the combined 18S rRNA and chloroplast gene tree, H. nozakii was sister to Lobochlamys.

  1. 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).

  2. 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.

  3. 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.

  4. Cyanea capillata Bell Kinematics Analysis through Corrected In Situ Imaging and Modeling Using Strategic Discretization Techniques

    PubMed Central

    Villanueva, Alex A.; Priya, Shashank

    2014-01-01

    Obtaining accurate kinematic data of animals is essential for many biological studies and bio-inspired engineering. Many animals, however, are either too large or too delicate to transport to controlled environments where accurate kinematic data can be easily obtained. Often, in situ recordings are the only means available but are often subject to multi-axis motion and relative magnification changes with time leading to large discrepancies in the animal kinematics. Techniques to compensate for these artifacts were applied to a large jellyfish, Cyanea capillata, freely swimming in ocean waters. The bell kinematics were captured by digitizing exumbrella profiles for two full swimming cycles. Magnification was accounted for by tracking a reference point on the ocean floor and by observing the C. capillata exumbrella arclength in order to have a constant scale through the swimming cycles. A linear fit of the top bell section was used to find the body angle with respect to the camera coordinate system. Bell margin trajectories over two swimming cycles confirmed the accuracy of the correction techniques. The corrected profiles were filtered and interpolated to provide a set of time-dependent points along the bell. Discrete models of the exumbrella were used to analyze the bell kinematics. Exumbrella discretization was conducted using three different methods. Fourier series were fitted to the discretized models and subsequently used to analyze the bell kinematics of the C. capillata. The analysis showed that the bell did not deform uniformly over time with different segments lagging behind each other. Looping of the bell trajectory between contraction and relaxation was also present through most of the exumbrella. The bell margin had the largest looping with an outer path during contraction and inner path during relaxation. The subumbrella volume was approximated based on the exumbrella kinematics and was found to increase during contraction. PMID:25541980

  5. 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

  6. 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.

  7. 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.

  8. Pain from bluebottle jellyfish stings.

    PubMed

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

    2015-07-01

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

  9. Cyanea capillata tentacle-only extract as a potential alternative of nematocyst venom: its cardiovascular toxicity and tolerance to isolation and purification procedures.

    PubMed

    Xiao, Liang; He, Qian; Guo, Yufeng; Zhang, Jing; Nie, Fei; Li, Yue; Ye, Xiaofei; Zhang, Liming

    2009-01-01

    As the proteins with cardiovascular toxicity in jellyfish nematocyst venom and tentacle-only extract (TOE) are probably encoded by the same gene, TOE provides a potential alternative of nematocyst venom with much richer source for acquisition of such proteins. In this study, Cyanea capillata nematocyst venom and TOE (5mg/kg) both exhibited cardiovascular toxicity in rats, and TOE caused blood pressure reduction in slightly greater amplitude than nematocyst venom 3min after intravenous administration. SDS-PAGE suggested high likeliness that they both contained the same bioactive protein. The activity of TOE was dose-dependent within 1.25-5mg/kg, but not at higher concentrations. The cardiovascular activity of TOE sustained a major loss after exposure to 60 degrees C, and was totally abolished after exposure to 80 degrees C. Within the pH range of 7-11, the activity of TOE was well preserved, and rapidly attenuated in pH below 5. At 4 degrees C, TOE lost cardiovascular toxicity after preservation for 7 days, which occurred only after an 8-h preservation at 20 degrees C. Repeated freeze-thawing and freeze-drying did not significantly affect the toxicity of TOE. Buffer solutions obviously affected the toxicity of TOE, and 0.02mol/L HAc (pH 6.0) was optimal. These results provide experimental data for optimizing the conditions for isolating the proteins with cardiovascular toxicity from jellyfish TOE, which serves as a promising alternative source of nematocyst venom.

  10. [Jellyfish sting. A case report].

    PubMed

    Tamás, Ildikó; Veres, Imre; Remenyik, Eva

    2008-01-06

    Jellyfish bites in Hungary are rare. Yet, from a differential diagnostic point of view this epizoonozis might gain importance given the ever-growing popularity of seaside tourism. A 10 year old female patient was stung by a jellyfish while sea-bathing in the Adriatic in the summer of 2005. A couple of minutes after the bite urticaria were formed in the contacted area accompanied by a burning and sore sensation. In a few hours the above lesions turned livid and the patient developed low-grade fever and general discomfort. In acute therapy she received thorough rinse with vinegar, antibiotic ointment and systemic calcium. General symptoms regressed within 24 hours and dermatological symptoms improved progressively. Finally, the patient grew symptomless in 4 weeks altogether due to general antihistamine and local antibiotic therapy. 3 months later the patient presented again with hyperaemic papules and an increasing itching and burning sensation in the previously jellyfish-contacted area. Histopathology showed vascular involvement and eosinophilic infiltration. The inflammatory symptoms gradually diminished to locally applied steroids in an occlusive bandage leaving behind hypopigmentation. Although bare-skin contact with the different poisonous jellyfish species usually do lead to the forming of dermatological symptoms, vascular involvement developed months after the encounter in the exposure site has seldom been published. The article covers the main potential symptoms of jellyfish stings--both local and general--going into details about the possible dermatological differential diagnoses. Furthermore, the most venomous jellyfish species, their geographical habitats, do's and don't-s of first aid, therapy and prevention are being briefly discussed by the authors.

  11. Social behaviour in mesopelagic jellyfish.

    PubMed

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

    2015-06-11

    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.

  12. 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

  13. 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.

  14. Defense by foot adhesion in a beetle (Hemisphaerota cyanea)

    PubMed Central

    Eisner, Thomas; Aneshansley, Daniel J.

    2000-01-01

    The beetle Hemisphaerota cyanea (Chrysomelidae; Cassidinae) responds to disturbance by activating a tarsal adhesion mechanism by which it secures a hold on the substrate. Its tarsi are oversized and collectively bear some 60,000 adhesive bristles, each with two terminal pads. While walking, the beetle commits but a small fraction of the bristles to contact with the substrate. But when assaulted, it presses its tarsi flatly down, thereby touching ground with all or nearly all of the bristles. Once so adhered, it can withstand pulling forces of up to 0.8 g (≈60 times its body mass) for 2 min, and of higher magnitudes, up to >3 g, for shorter periods. Adhesion is secured by a liquid, most probably an oil. By adhering, the beetle is able to thwart attacking ants, given that it is able to cling more persistently than the ant persists in its assault. One predator, the reduviid Arilus cristatus, is able to feed on the beetle, possibly because by injecting venom it prevents the beetle from maintaining its tarsal hold. PMID:10841556

  15. Defense by foot adhesion in a beetle (Hemisphaerota cyanea)

    NASA Astrophysics Data System (ADS)

    Eisner, Thomas; Aneshansley, Daniel J.

    2000-06-01

    Departments of * Neurobiology and Behavior and Agricultural and Biological Engineering, Cornell University, Ithaca, NY 14853 Contributed by Thomas Eisner, April 12, 2000 The beetle Hemisphaerota cyanea (Chrysomelidae; Cassidinae) responds to disturbance by activating a tarsal adhesion mechanism by which it secures a hold on the substrate. Its tarsi are oversized and collectively bear some 60,000 adhesive bristles, each with two terminal pads. While walking, the beetle commits but a small fraction of the bristles to contact with the substrate. But when assaulted, it presses its tarsi flatly down, thereby touching ground with all or nearly all of the bristles. Once so adhered, it can withstand pulling forces of up to 0.8 g (≈60 times its body mass) for 2 min, and of higher magnitudes, up to >3 g, for shorter periods. Adhesion is secured by a liquid, most probably an oil. By adhering, the beetle is able to thwart attacking ants, given that it is able to cling more persistently than the ant persists in its assault. One predator, the reduviid Arilus cristatus, is able to feed on the beetle, possibly because by injecting venom it prevents the beetle from maintaining its tarsal hold.

  16. Defense by foot adhesion in a beetle (Hemisphaerota cyanea).

    PubMed

    Eisner, T; Aneshansley, D J

    2000-06-06

    The beetle Hemisphaerota cyanea (Chrysomelidae; Cassidinae) responds to disturbance by activating a tarsal adhesion mechanism by which it secures a hold on the substrate. Its tarsi are oversized and collectively bear some 60,000 adhesive bristles, each with two terminal pads. While walking, the beetle commits but a small fraction of the bristles to contact with the substrate. But when assaulted, it presses its tarsi flatly down, thereby touching ground with all or nearly all of the bristles. Once so adhered, it can withstand pulling forces of up to 0.8 g ( approximately 60 times its body mass) for 2 min, and of higher magnitudes, up to >3 g, for shorter periods. Adhesion is secured by a liquid, most probably an oil. By adhering, the beetle is able to thwart attacking ants, given that it is able to cling more persistently than the ant persists in its assault. One predator, the reduviid Arilus cristatus, is able to feed on the beetle, possibly because by injecting venom it prevents the beetle from maintaining its tarsal hold.

  17. Biomimetic autonomous robot inspired by the Cyanea capillata (Cyro).

    PubMed

    Villanueva, Alex A; Marut, Kenneth J; Michael, Tyler; Priya, Shashank

    2013-12-01

    A biomimetic robot inspired by Cyanea capillata, termed as 'Cyro', was developed to meet the functional demands of underwater surveillance in defense and civilian applications. The vehicle was designed to mimic the morphology and swimming mechanism of the natural counterpart. The body of the vehicle consists of a rigid support structure with linear DC motors which actuate eight mechanical arms. The mechanical arms in conjunction with artificial mesoglea create the hydrodynamic force required for propulsion. The full vehicle measures 170 cm in diameter and has a total mass of 76 kg. An analytical model of the mechanical arm kinematics was developed. The analytical and experimental bell kinematics were analyzed and compared to the C. capillata. Cyro was found to reach the water surface untethered and autonomously from a depth of 182 cm in five actuation cycles. It achieved an average velocity of 8.47 cm s(-1) while consuming an average power of 70 W. A two-axis thrust stand was developed to calculate the thrust directly from a single bell segment yielding an average thrust of 27.9 N for the whole vehicle. Steady state velocity during Cyro's swimming test was not reached but the measured performance during its last swim cycle resulted in a cost of transport of 10.9 J (kg ⋅ m)(-1) and total efficiency of 0.03.

  18. Pharmacological characterization of Synoeca cyanea venom: an aggressive social wasp widely distributed in the Neotropical region.

    PubMed

    Mortari, Márcia Renata; do Couto, Lucianna Lopes; dos Anjos, Lilian Carneiro; Mourão, Caroline Barbosa Farias; Camargos, Thalita Soares; Vargas, Jimmy Alexander Guerrero; Oliveira, Fagner Neves; Gati, Christiano Del Cantoni; Schwartz, Carlos Alberto; Schwartz, Elisabeth Ferroni

    2012-01-01

    The venom of social wasps has been poorly studied so far, despite the high number of accidents in humans and assessment of the use of these wasps as a biological control of pests. The study of the pharmacological effects of the venom is of great importance since the poisoning is dangerous causing serious systemic effects, including death in the case of multiple attacks. In this study, the pharmacological activities of venom from the social wasp Synoeca cyanea were evaluated by the following assays: LD50 in mice, the behavioural effects and the hemorrhagic activity induced by the venom in mice, the oedematogenic activity in rat, the haemolysis in human blood, the stimulating effect on guinea-pig smooth muscle, and the antimicrobial activity. The aim was to determine the toxic effects of venom and to perform a comparative study with earlier work conducted with venom from other wasp species. Results showed that S. cyanea venom produced a potent dose-dependent oedema, as well as antibacterial and haemolytic activities, suggesting the presence of histamine, serotonin, kinins and other molecules related to increased vascular permeability and cytolytic activity in this venom. Despite previous studies with wasp venoms, S. cyanea venom presented a slight hemorrhagic effect. Data obtained in the smooth muscle assay also suggest the presence of BK or analogues in S. cyanea whole venom. The knowledge of symptoms and effects produced by S. cyanea venom is critical for health organizations, in order to improve clinical treatment in accidents caused by wasp stings.

  19. A new species of Cyanea (Campanulaceae, Lobelioideae) from Maui, Hawaiian Islands

    PubMed Central

    Oppenheimer, Hank; Lorence, David H.

    2012-01-01

    Abstract Cyanea kauaulaensis H. Oppenheimer & Lorence, sp. nov., a new, narrowly endemic species from Maui, Hawaiian Islands is described, illustrated with field photos, and its affinities and conservation status are discussed. It is currently known from 62 mature plants and is restricted to Kaua`ula and Waikapu valleys on leeward western Maui. It differs from all other species of Cyanea by its combination of many-branched habit; glabrous, unarmed, undivided leaves; small, narrow, glabrous corollas with small calyx lobes that do not persist in fruit; and bright orange, subglobose to obovoid fruits. PMID:22787424

  20. Exploring the therapeutic potential of jellyfish venom.

    PubMed

    Daly, Norelle L; Seymour, Jamie; Wilson, David

    2014-10-01

    The venom of certain jellyfish has long been known to be potentially fatal to humans, but it is only recently that details of the proteomes of these fascinating creatures are emerging. The molecular contents of the nematocysts from several jellyfish species have now been analyzed using proteomic MS approaches and include the analysis of Chironex fleckeri, one of the most venomous jellyfish known. These studies suggest that some species contain toxins related to peptides and proteins found in other venomous creatures. The detailed characterization of jellyfish venom is likely to provide insight into the diversification of toxins and might be a valuable resource in drug design.

  1. 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

  2. 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.

  3. Immunological and toxinological responses to jellyfish stings.

    PubMed

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

    2011-10-01

    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.

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

    PubMed Central

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

    2015-01-01

    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

  5. 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.

  6. 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

  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. Micro- and macrorheology of jellyfish extracellular matrix.

    PubMed

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

    2012-01-04

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

  9. Comparative gastrointestinal morphology of three small mammalian insectivores: Acomys spinosissimus (Rodentia), Crocidura cyanea (Eulipotyphla), and Amblysomus hottentotus (Afrosoricida).

    PubMed

    Boonzaier, Julia; Van der Merwe, Elizabeth L; Bennett, Nigel C; Kotzé, Sanet H

    2013-06-01

    The gastrointestinal morphology was investigated in three mammalian insectivorous species, namely Acomys spinosissimus, Crocidura cyanea, and Amblysomus hottentotus. The aim of the study was to provide a comprehensive morphological comparison between the different species and to explore whether anatomical gastrointestinal adaptations are associated with the insectivorous diet of these species. The shape, proportional length, and proportional surface areas of the different gastrointestinal regions were recorded and compared in the three insectivores. Hematoxylin and Eosin (H&E) and Alcian Blue/Periodic Acid Schiff (AB/PAS) were used for morphological assessment. In all three species, the stomach was simple and uncompartmentalized. The internal aspect of the stomach in A. spinosissimus was hemi-glandular, containing stratified squamous epithelium in the fundus, with glandular epithelium in the body and pyloric region. However, C. cyanea and A. hottentotus had wholly glandular stomachs. Paneth cells were not observed in the intestinal tracts of C. cyanea and A. hottentotus. Acomys spinosissimus was the only species studied that had a cecum. The proximal colonic region of A. spinosissimus had V-shaped mucosal folds. Histologically, C. cyanea had villi throughout the entire gastrointestinal tract (GIT), whereas for A. hottentotus villi were not present in the most distal gastrointestinal regions. In both C. cyanea and A. hottentotus, longitudinal mucosal folds were present in the distal part of the colon. The GITs of C. cyanea and A. hottentotus showed little morphological differentiation namely, a simple, glandular stomach and the lack of a cecum.

  10. The Jellyfish hunter--Jack Barnes: a pioneer medical toxinologist in Australia.

    PubMed

    Pearn, John; Fenner, Peter

    2006-12-01

    Dr Jack Handyside Barnes (1922-1985) was one of the small and elite group of Pacific marine toxinologists whose work was characterised by an uncompromising rugged persona, a focussed resolve to solve challenging problems of human clinical envenomation, and who conducted curiosity-driven research under conditions of scientific isolation. He was a pioneering advocate for the preservation of marine heritage, particularly that of the Great Barrier Reef. A former military commando who later became a general medical practitioner with extensive surgical and obstetric skills, in 1947 he was appointed the Medical Superintendent of Thursday Island in the Torres Strait. Later (from January 1953), he worked indefatigably as a general medical practitioner in Cairns, in tropical North Australia. For four decades (1945-1985), Jack Barnes undertook detailed laboratory, clinical and field research into invertebrate envenomation, particularly medusan toxinology. In 1960 he discovered the species responsible for the Irukandji syndrome, a small carybdeid named Carukia barnesi in his honour. He invented the research technique for the extraction of venom from the world's most venomous creature, the Pacific box Jellyfish, Chironex fleckeri. By 1960, he had published taxonomic details of nematocyst structure and clinical envenomation details consequent upon stings by Physalia, Cyanea, Chironex, Chiropsalmus and Carukia. This paper is a précis of the chronology of his life, contributions and influence.

  11. Genome sequence of the chemoheterotrophic soil bacterium Saccharomonospora cyanea type strain (NA-134(T)).

    PubMed

    Meier-Kolthoff, Jan P; Lu, Megan; Huntemann, Marcel; Lucas, Susan; Lapidus, Alla; Copeland, Alex; Pitluck, Sam; Goodwin, Lynne A; Han, Cliff; Tapia, Roxanne; Pötter, Gabriele; Land, Miriam; Ivanova, Natalia; Rohde, Manfred; Göker, Markus; Detter, John C; Woyke, Tanja; Kyrpides, Nikos C; Klenk, Hans-Peter

    2013-10-16

    Saccharomonospora cyanea Runmao et al. 1988 is a member of the genus Saccharomonospora in the family Pseudonocardiaceae that is moderately well characterized at the genome level thus far. Members of the genus Saccharomonospora are of interest because they originate from diverse habitats, such as soil, leaf litter, manure, compost, surface of peat, moist, over-heated grain, and ocean sediment, where they probably play a role in the primary degradation of plant material by attacking hemicellulose. Species of the genus Saccharomonospora are usually Gram-positive, non-acid fast, and are classified among the actinomycetes. S. cyanea is characterized by a dark blue (= cyan blue) aerial mycelium. After S. viridis, S. azurea, and S. marina, S. cyanea is only the fourth member in the genus for which a completely sequenced (non-contiguous finished draft status) type strain genome will be published. Here we describe the features of this organism, together with the draft genome sequence, and annotation. The 5,408,301 bp long chromosome with its 5,139 protein-coding and 57 RNA genes was sequenced as part of the DOE funded Community Sequencing Program (CSP) 2010 at the Joint Genome Institute (JGI).

  12. Genome sequence of the chemoheterotrophic soil bacterium Saccharomonospora cyanea type strain (NA-134T)

    PubMed Central

    Meier-Kolthoff, Jan P.; Lu, Megan; Huntemann, Marcel; Lucas, Susan; Lapidus, Alla; Copeland, Alex; Pitluck, Sam; Goodwin, Lynne A.; Han, Cliff; Tapia, Roxanne; Pötter, Gabriele; Land, Miriam; Ivanova, Natalia; Rohde, Manfred; Göker, Markus; Detter, John C.; Woyke, Tanja; Kyrpides, Nikos C.; Klenk, Hans-Peter

    2013-01-01

    Saccharomonospora cyanea Runmao et al. 1988 is a member of the genus Saccharomonospora in the family Pseudonocardiaceae that is moderately well characterized at the genome level thus far. Members of the genus Saccharomonospora are of interest because they originate from diverse habitats, such as soil, leaf litter, manure, compost, surface of peat, moist, over-heated grain, and ocean sediment, where they probably play a role in the primary degradation of plant material by attacking hemicellulose. Species of the genus Saccharomonospora are usually Gram-positive, non-acid fast, and are classified among the actinomycetes. S. cyanea is characterized by a dark blue (= cyan blue) aerial mycelium. After S. viridis, S. azurea, and S. marina, S. cyanea is only the fourth member in the genus for which a completely sequenced (non-contiguous finished draft status) type strain genome will be published. Here we describe the features of this organism, together with the draft genome sequence, and annotation. The 5,408,301 bp long chromosome with its 5,139 protein-coding and 57 RNA genes was sequenced as part of the DOE funded Community Sequencing Program (CSP) 2010 at the Joint Genome Institute (JGI). PMID:24501643

  13. Genome sequence of the chemoheterotrophic soil bacterium Saccharomonospora cyanea type strain (NA-134(T))

    SciTech Connect

    Meier-Kolthoff, Jan P.; Lu, Megan; Huntemann, Marcel; Lucas, Susan; Lapidus, Alla L.; Copeland, A; Pitluck, Sam; Goodwin, Lynne A.; Han, Cliff; Tapia, Roxanne; Potter, Gabriele; Land, Miriam L; Ivanova, N; Rohde, Manfred; Goker, Markus; Detter, J. Chris; Woyke, Tanja; Kyrpides, Nikos C; Klenk, Hans-Peter

    2013-01-01

    Saccharomonospora cyanea Runmao et al. 1988 is a member of the genus Saccharomonospora in the family Pseudonocardiaceae that is moderately well characterized at the genome level thus far. Members of the genus Saccharomonospora are of interest because they originate from diverse habitats, such as soil, leaf litter, manure, compost, surface of peat, moist, over-heated grain, and ocean sediment, where they probably play a role in the primary degradation of plant material by attacking hemicellulose. Species of the genus Saccharomonospora are usually Gram-positive, non-acid fast, and are classified among the actinomycetes. S. cyanea is characterized by a dark blue (= cyan blue) aerial mycelium. After S. viridis, S. azurea, and S. marina, S. cyanea is only the fourth member in the genus for which a completely sequenced (non-contiguous finished draft status) type strain genome will be published. Here we describe the features of this organism, together with the draft genome sequence, and annotation. The 5,408,301 bp long chromosome with its 5,139 protein-coding and 57 RNA genes was sequenced as part of the DOE funded Community Sequencing Program (CSP) 2010 at the Joint Genome Institute (JGI).

  14. 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

    2007-10-31

    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.

  15. Simulation of Piezoelectric Jellyfish Power Generator

    NASA Astrophysics Data System (ADS)

    Wu, Yeong-Jen; Lai, Wei-Hsiang

    The energy problem is getting increasingly serious. As such, unused energy recovery technology is crucial for environmental protection, which has been investigated extensively. Several methods have been developed to utilize scavenged energy from the environment, such as waste heat, solar energy, wind energy, and tides energy to convert into useful power. There is a new idea of piezoelectric jellyfish generator which combines the utilization of sea wave and vibration energy. When sea wave passes through the jellyfish, the wave causes the tentacles to vibrate. The tentacles is made of piezoelectric polymer which can convert the strain energy into electrical energy. This paper discusses about the piezoelectric jellyfish's tentacles being disturbed by wave in the sea. We employed the commercial CFD software CFD-ACE+ 2006 to simulate this phenomenon. The parameters including its tentacle length (L) and wave propagating function (Y) are studied which affect the piezoelectric jellyfish capacity to generate power.

  16. 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

  17. 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.

  18. 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.

  19. 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

  20. 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.

  1. 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

  2. Recurrent jellyfish blooms are a consequence of global oscillations

    PubMed Central

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

    2013-01-01

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

  3. 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.

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

    PubMed

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

    2015-11-01

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

  5. 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

  6. Jellyfish body plans provide allometric advantages beyond low carbon content.

    PubMed

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

    2013-01-01

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

  7. [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

  8. Digital ischaemia: a rare but severe complication of jellyfish sting.

    PubMed

    Lam, Stacey C; Hung, Y W; Chow, Esther C S; Wong, Clara W Y; Tse, W L; Ho, P C

    2014-10-01

    We report a case of digital ischaemia in a 31-year-old man who presented with sudden hand numbness, swelling, and cyanosis 4 days after a jellyfish sting. This is a rare complication of jellyfish sting, characterised by a delayed but rapid downhill course. Despite serial monitoring with prompt fasciotomy and repeated debridement, he developed progressive ischaemia in multiple digits with gangrenous change. He subsequently underwent major reconstructive surgery and aggressive rehabilitation. Although jellyfish stings are not uncommon, no severe jellyfish envenomation has been reported in the past in Hong Kong and there has not been any consensus on the management of such injuries. This is the first local case report of jellyfish sting leading to serious hand complications. This case revealed that patients who sustain a jellyfish sting deserve particular attention to facilitate early detection of complications and implementation of therapy.

  9. 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.

  10. 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.

  11. Jellyfish collagen scaffolds for cartilage tissue engineering.

    PubMed

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

    2014-02-01

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

  12. 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

  13. 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.

  14. 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.

  15. A new species of Cyanea (Campanulaceae, Lobelioideae), from the Ko‘olau Mountains of O‘ahu, Hawaiian Islands

    PubMed Central

    Sporck-Koehler, Margaret J.; Koehler, Tobias B.; Marquez, Sebastian N.; Waite, Mashuri; Williams, Adam M.

    2015-01-01

    Abstract Cyanea konahuanuiensis Sporck-Koehler, M. Waite, A.M. Williams, sp. nov., a recently documented, narrowly endemic species from the Hawaiian Island of O‘ahu, is described and illustrated with photographs from the field. The closest likely relatives to the species, current conservation needs, and management future are discussed. It is currently known from 20 mature plants from two subpopulations and is restricted to a drainage below the Kōnāhua-nui summit (K1), the highest summit of the Ko‘olau Mountains, located on Windward O‘ahu. It differs from all other Cyanea species by its combination of densely pubescent leaves, petioles, and flowers; sparsely pubescent to glabrous stems, long calyx lobes, and staminal column being adnate to the corolla. PMID:25829854

  16. 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.

  17. [Variations of the infracommuity during the ontogeny of Chromis cyanea (Perciformes: Pomcentride) in the North coast of Havana, Cuba].

    PubMed

    Fernández Osorio, Ramón Alexis; Corrada Wong, Raúl Igor; Armenteros, Maickel

    2015-09-01

    The infracommunty or parasites or unromis cyanea (Pisces: Pomacentridae) was studied along the ontogenetic development in the North coast of Havana, Cuba. The objectives were: a- to prove that the core species appears before the strange and stochastic species and they are responsible for the structure in the infracommunity, b- to determine if there is a relationship among the ecological describers of the parasitic infracommunity with the total length. A total of 278 specimens of C. cyanea were captured during the dry season (April) of 2010. The body size range was from 1.5 to 11.5 cm including juvenile and adults. We collected 2 861 parasite specimens belonging to 20 taxa: Crustacea (5), Nematoda (5), Trematoda (4), Cestoda (2), Monogenea (2), Turbellaria (1) and Ciliophora (1). The taxa Tetraphyllidea and Anilocra chromis constituted the core of the parasitic infracommunity. The sequence of appearance and persistence of these taxa during the ontogenetic development, supported the hypothesis of the core species. The changes in the infracommunity, from 6 cm body size, could be the result of an accumulative effect combined with changes of the diet that caused the ingestion of new parasite infective stages. We concluded that the ontogenetic development of C. cyanea constitutes an important variable in the formation of the parasitic infracommunity.

  18. 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.

  19. Thorn-like prickles and heterophylly in Cyanea: adaptations to extinct avian browsers on Hawaii?

    PubMed Central

    Givnish, T J; Sytsma, K J; Smith, J F; Hahn, W J

    1994-01-01

    The evolution of thorn-like structures in plants on oceanic islands that lack mammalian and reptilian herbivores is puzzling, as is their tendency toward juvenile-adult leaf dimorphism. We propose that these traits arose in Cyanea (Campanulaceae) on Hawaii as mechanical and visual defenses against herbivory by flightless geese and goose-like ducks that were extirpated by Polynesians within the last 1600 years. A chloroplast DNA phylogeny indicates that thorn-like prickles evolved at least four times and leaf dimorphism at least three times during the last 3.7 million years. The incidence of both traits increases from Oahu eastward toward younger islands, paralleling the distribution of avian species apparently adapted for browsing. The effectiveness of visual defenses against avian browsers (once dominant on many oceanic islands, based on the vagility of their ancestors) may provide a general explanation for insular heterophylly: the other islands on which this previously unexplained phenomenon is marked (New Zealand, New Caledonia, Madagascar, Mascarene Islands) are exactly those on which one or more large flightless avian browsers evolved. Images PMID:11607469

  20. The mechanoreceptors on the endophytic ovipositor of the dragonfly Aeshna cyanea (Odonata, Aeshnidae).

    PubMed

    Rebora, Manuela; Piersanti, Silvana; Gaino, Elda

    2013-09-01

    This study investigates the mechanoreceptors located on the cutting valvulae of the ovipositor of the dragonfly Aeshna cyanea (Aeshnidae), using both SEM and TEM, with the aim of providing an overview of the sensory equipment of an odonatan endophytic ovipositor. Four kinds of sensilla have been described. Notwithstanding their different external and internal morphology, they show features typical of mechanoreceptors. Three of them are evident along the external surface of the two cutting valvulae in the form of sub-spherical pegs, pit organs type 1 (holes) and pit organs type 2 (depressions), these last are similar to amphinematic scolopidia, while the fourth type is represented by subintegumental mononematic scolopidia having no direct relationship with the cuticle. In spite of their structural differences, the morphology of the described mechanoreceptors is consistent with performing a main role in allowing the perception of compression/stretching of the thick cuticle of the valvulae and their bending due to the pressure acting on the distal end of the ovipositor during substrate penetration. Such an organization is coherent with the need of endophytic Odonata to be able to evaluate the stiffness of the plant where to lay eggs.

  1. 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.

  2. Evolution and functional diversity of jellyfish opsins.

    PubMed

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

    2008-01-08

    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.

  3. 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.

  4. Environmental forcing on jellyfish communities in a small temperate estuary.

    PubMed

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

    2012-08-01

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

  5. Environmental DNA reflects spatial and temporal jellyfish distribution

    PubMed Central

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

    2017-01-01

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

  6. Environmental DNA reflects spatial and temporal jellyfish distribution.

    PubMed

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

    2017-01-01

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

  7. 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).

  8. 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.

  9. 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.

  10. JELLYFISH GALAXY CANDIDATES AT LOW REDSHIFT

    SciTech Connect

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

    2016-03-15

    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 L{sub X}. Interestingly, convincing cases of candidates are also found in groups and lower mass halos (10{sup 11}−10{sup 14}M{sub ⊙}), although the physical mechanism at work needs to be securely identified. All the candidates are disky, have stellar masses ranging from log M/M{sub ⊙} < 9 to > 11.5 and the majority of them form stars at a rate that is on average a factor of 2 higher (2.5σ) compared to non-stripped galaxies of similar mass. The few post-starburst and passive candidates have weak stripping evidence. We conclude that disturbed morphologies suggestive of stripping phenomena are ubiquitous in clusters and could be present even in groups and low mass halos. Further studies will reveal the physics of the gas stripping and clarify the mechanisms at work.

  11. 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.

  12. 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

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

    PubMed

    Pierce, Justin

    2009-03-01

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

  14. Vibrio caribbeanicus sp. nov., isolated from the marine sponge Scleritoderma cyanea.

    PubMed

    Hoffmann, Maria; Monday, Steven R; Allard, Marc W; Strain, Errol A; Whittaker, Paul; Naum, Marianna; McCarthy, Peter J; Lopez, Jose V; Fischer, Markus; Brown, Eric W

    2012-08-01

    A Gram-negative, oxidase-positive, catalase-negative, facultatively anaerobic, motile, curved rod-shaped bacterium, strain N384(T), was isolated from a marine sponge (Scleritoderma cyanea; phylum Porifera) collected from a depth of 795 feet (242 m) off the west coast of Curaçao. On the basis of 16S rRNA gene sequencing, strain N384(T) was shown to belong to the genus Vibrio, most closely related to Vibrio brasiliensis LMG 20546(T) (98.8% similarity), Vibrio nigripulchritudo ATCC 27043(T) (98.5%), Vibrio tubiashii ATCC 19109(T) (98.6%) and V. sinaloensis DSM 21326(T) (98.2%). The DNA G+C content of strain N384(T) was 41.6 mol%. An analysis of concatenated sequences of five genes (gyrB, rpoA, pyrH, mreB and ftsZ; 4068 bp) demonstrated a clear separation between strain N384(T) and its closest neighbours and clustered strain N384(T) into the 'Orientalis' clade of vibrios. Phenotypically, the novel species belonged to the arginine dihydrolase-positive, lysine decarboxylase- and ornithine decarboxylase-negative (A+/L-/O-) cluster. The novel species was also differentiated on the basis of fatty acid composition, specifically that the proportions of iso-C(13:0), iso-C(15:0), C(15:0), iso-C(16:0), C(16:0), iso-C(17:0), C(17:1)ω8c and C(17:0) were significantly different from those found in V. brasiliensis and V. sinaloensis. The results of DNA-DNA hybridization, average nucleotide identity and physiological and biochemical tests further allowed differentiation of this strain from other described species of the genus Vibrio. Collectively, these findings confirm that strain N384(T) represents a novel Vibrio species, for which the name Vibrio caribbeanicus sp. nov. is proposed, with the type strain N384(T) ( = ATCC BAA-2122(T) = DSM 23640(T)).

  15. 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

  16. Identification of genetically and oceanographically distinct blooms of jellyfish.

    PubMed

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

    2013-03-06

    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.

  17. 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

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

    PubMed

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

    2015-07-08

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

  19. 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.

  20. 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.

  1. A new species of Cyanea (Campanulaceae, Lobelioideae), from the Ko'olau Mountains of O'ahu, Hawaiian Islands.

    PubMed

    Sporck-Koehler, Margaret J; Koehler, Tobias B; Marquez, Sebastian N; Waite, Mashuri; Williams, Adam M

    2015-01-01

    Cyaneakonahuanuiensis Sporck-Koehler, M. Waite, A.M. Williams, sp. nov., a recently documented, narrowly endemic species from the Hawaiian Island of O'ahu, is described and illustrated with photographs from the field. The closest likely relatives to the species, current conservation needs, and management future are discussed. It is currently known from 20 mature plants from two subpopulations and is restricted to a drainage below the Kōnāhua-nui summit (K1), the highest summit of the Ko'olau Mountains, located on Windward O'ahu. It differs from all other Cyanea species by its combination of densely pubescent leaves, petioles, and flowers; sparsely pubescent to glabrous stems, long calyx lobes, and staminal column being adnate to the corolla.

  2. 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

  3. Skin and Systemic Manifestations of Jellyfish Stings in Iraqi Fishermen

    PubMed Central

    Al-Rubiay, KK; Al-Musaoi, HA; Alrubaiy, L; Al-Freje, MG

    2009-01-01

    Background: Jellyfish stings are common worldwide with an estimated 150 million cases annually, and their stings cause a wide range of clinical manifestations from skin inflammation to cardiovascular and respiratory collapse. No studies on jellyfish stings have been carried out in Basra, Iraq. Objectives: To describe the immediate and delayed skin reactions to White Jellyfish (Rhizostoma sp.) stings and the types of local treatment used by fishermen. Methods and Materials: 150 fishermen were enrolled at three Marine stations in Basra, Iraq. Demographic data, types of skin reactions, systemic manifestations and kinds of treatments were collected. Results: Overall, 79% of fishermen in all three Marine stations gave a history of having been stung. The common sites of sings were the hands and arms followed by the legs. Most fishermen claimed that stings led to skin reactions within 5 minutes. The presenting complaints were itching, burning sensation, and erythematic wheals. A few days after the sting, new groups of painless and itchy erythematous monomorphic papular rashes developed at the site of the sting in 62% of cases as a delayed type of skin reaction that resolved spontaneously. The local remedies commonly used by the fishermen were seawater, tap water and ice. A few fishermen considered stings as insignificant and did not think there was a need to seek medical help. Conclusions: We conclude that jellyfish causes many stings among fishermen in the Basra region. Their stings lead to immediate and delayed skin reactions. Self-treatment by topical remedies is common. PMID:21483513

  4. 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).

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

    PubMed

    Frazão, Bárbara; Antunes, Agostinho

    2016-04-12

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

  6. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2016-11-01

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

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

    PubMed

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

    2012-01-01

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

  9. Cytochalasin derivatives from a jellyfish-derived fungus Phoma sp.

    PubMed

    Kim, Eun La; Wang, Haibo; Park, Ju Hee; Hong, Jongki; Choi, Jae Sue; Im, Dong Soon; Chung, Hae Young; Jung, Jee H

    2015-01-01

    Four new cytochalasin derivatives (1-4), together with proxiphomin (5), were isolated from a jellyfish-derived fungus Phoma sp. The planar structures and relative stereochemistry were established by analysis of 1D and 2D NMR data. The absolute configuration was defined by the modified Mosher's method. The compounds showed moderate cytotoxicity against a small panel of human solid tumor cell lines (A549, KB, and HCT116).

  10. 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

  11. 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.

  12. 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

  13. Autonomic neurotoxicity of jellyfish and marine animal venoms.

    PubMed

    Burnett, J W; Weinrich, D; Williamson, J A; Fenner, P J; Lutz, L L; Bloom, D A

    1998-04-01

    Venoms and poisons of jellyfish and other marine animals can induce damage to the human nervous and circulatory systems. Clues to the pathogenesis and clinical manifestations of these lesions can be obtained from data of human envenomations and animal experimentation. Because many investigators are unaware that marine animal venoms have autonomic actions, this paper aims to elucidate the broad antagonistic or toxic effects these compounds have on the autonomic nervous system. Marine venoms can affect ion transport of particularly sodium and calcium, induce channels or pores in neural and muscular cellular membranes, alter intracellular membranes of organelles and release mediators of inflammation. The box jellyfish, particularly Chironex fleckeri, in the Indo-Pacific region, is the world's most venomous marine animal and is responsible for autonomic disorders in patients. The symptoms induced by these venoms are vasospasm, cardiac irregularities, peripheral neuropathy, aphonia, ophthalmic abnormalities and parasympathetic dysautonomia. Cases of Irukandji syndrome, caused by the jellyfish Carukia barnesi, have symptoms that mimic excessive catecholamine release. Coelenterate venoms can also target the myocardium, Purkinje fiber, A-V node or aortic ring. Actions on nerves, as well as skeletal, smooth or cardiac muscle occur. Recent studies indicate that the hepatic P-450 enzyme family may be injured by these compounds. The multiplicity of these venom activities means that a thorough understanding of the sting pathogenesis will be essential in devising effective therapies.

  14. 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.

  15. 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

  16. 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.

  17. 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

    2015-07-29

    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.

  18. Modeling jellyfish Pelagia noctiluca transport and stranding in the Ligurian Sea.

    PubMed

    Berline, L; Zakardjian, B; Molcard, A; Ourmières, Y; Guihou, K

    2013-05-15

    Jellyfish blooms are generally attributed to a biological response to the environment, neglecting the role of transport patterns in redistributing existing populations. Here, we use high-resolution (1.25km) ocean modeling to examine the role of transport in the onshore arrival and abundance of the pelagic stinging jellyfish Pelagia noctiluca on the Ligurian Sea coast. Jellyfish are modeled as Lagrangian particles with a 0-300-m diel vertical migration typical of P. noctiluca. Over the course of a year, onshore arrivals are not restricted to the summer. Arrivals are concentrated at capes, but abundance can reach maxima in bays and in the lee of capes. Two factors impact jellyfish arrivals at the coast: the position of the Northern Current and the wind. A comparison of summer 2006 and available onshore jellyfish observations suggests a correct capture of the main stranding events by the model. These results have implications for understanding long-term fluctuations.

  19. Long-chain alkanes and fatty acids from Ludwigia octovalvis weed leaf surface waxes as short-range attractant and ovipositional stimulant to Altica cyanea (Weber) (Coleoptera: Chrysomelidae).

    PubMed

    Mitra, S; Sarkar, N; Barik, A

    2017-01-30

    The importance of leaf surface wax compounds from the rice-field weed Ludwigia octovalvis (Jacq.) Raven (Onagraceae) was determined in the flea beetle Altica cyanea (Weber) (Coleoptera: Chrysomelidae). Extraction, thin layer chromatography and GC-MS and GC-FID analyses of surface waxes of young, mature and senescent leaves revealed 20, 19 and 19 n-alkanes between n-C15 and n-C35, respectively; whereas 14, 14 and 12 free fatty acids between C12:0 and C22:0 fatty acids were identified in young, mature and senescent leaves, respectively. Tricosane was predominant n-alkane in young and mature leaves, whilst eicosane predominated in senescent leaves. Heneicosanoic acid, palmitic acid and docosanoic acid were the most abundant free fatty acids in young, mature and senescent leaves, respectively. A. cyanea females showed attraction to 0.25 mature leaf equivalent surface waxes compared with young or senescent leaves in a short glass Y-tube olfactometer bioassay. The insects were attracted to a synthetic blend of 0.90, 1.86, 1.83, 1.95, 0.50 and 0.18 µg ml-1 petroleum ether of hexadecane, octadecane, eicosane, tricosane, palmitic acid and alpha-linolenic acid, respectively, comparable with the proportions as present in 0.25 mature leaf equivalent surface waxes. A. cyanea also laid eggs on a filter paper moistened with 0.25 mature leaf equivalent surface waxes or a synthetic blend of 0.90, 1.86, 1.83, 1.95, 0.50 and 0.18 µg ml-1 petroleum ether of hexadecane, octadecane, eicosane, tricosane, palmitic acid and alpha-linolenic acid, respectively. This finding could provide a basis for monitoring of the potential biocontrol agent in the field.

  20. 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

  1. 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.

  2. 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.

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

    PubMed

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

    2014-02-27

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

  4. 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

  5. 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.

  6. [Olindias sambaquiensis jellyfish sting. Analysis of 49 cases].

    PubMed

    Mosovich, Juan H; Young, Pablo

    2012-01-01

    Olindias sambaquiensis jellyfish sting occurs frequently in Buenos Aires province coast beaches. Among five hundred and one thousand stings by jellyfish are reported each season at Monte Hermoso, a beach village in the South of Buenos Aires province. The skin damage provoked because of its highly irritant effect poses a serious issue related to tourism development. A total number of 49 cases that were examined during the first hour after the sting were enrolled in Monte Hermoso during January 1998. Twenty eight were males (57.1%). The average age was 16 ± 4.1 (range 5-80). Of them, 54% showed linear erythema-edematous lesions, 28% showed predominantly erythematous lesions, and in 18% the injuries were erythema-edematous plaques. In 73% of the cases the lesions were located in lower limbs. We had hereby redefined cutaneous lesions produced by O. sambaquiensis, its evolution, its dimensions and most frequent localizations. Besides, it has been typified and quantified the pain it provokes and other signs and symptoms that go with the sting during the posterior hour, during the first 24 hours, and after 30 days. We described the therapeutic conducts used in our coasts and we assessed the effectiveness of some of them in pain control, and finally we propose a therapeutic scheme for this sting.

  7. 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

  8. 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.

  9. Dangers in the ocean: the traveler and marine envenomation. I. jellyfish.

    PubMed

    Fenner, P J

    1998-09-01

    Envenomation by marine creatures is more common than is often realized, and regularly accounts for both death and severe morbidity in humans. Worldwide marine envenomation morbidity and mortality result from two main animal groups: (1) jellyfish, and (2) "other" marine animals. Venomous jellyfish are discussed in part I of this article, with relevant information on their distribution and appearance, and on symptoms of envenomation; first aid and medical treatment are also suggested.

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

    PubMed

    Little, Mark; Fitzpatrick, Richard; Seymour, Jamie

    2016-11-01

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

  11. 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.

  12. 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' jellyfish Mastigias cf.papua and the box jellyfish Tripedalia cf.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 to Mastigias whereas Spirochaetes and the order Kiloniellales were most abundant in Tripedalia hosts. 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 in Mastigias hosts and OTUs assigned to the Spirochaetes and order Kiloniellales and mainly found in Tripedalia hosts. The low sequence similarity of the Entomoplasmatales OTU to sequences in Genbank suggests that it may be a novel lineage inhabiting Mastigias and possibly restricted to marine lakes.

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

    PubMed

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

    2014-08-01

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

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

    PubMed

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

    2013-05-22

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

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

    NASA Astrophysics Data System (ADS)

    Wu, Lingjuan; Wu, Xiaofen; Bai, Tao

    2016-09-01

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

  16. High activity and Levy searches: jellyfish can search the water column like fish.

    PubMed

    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

    2012-02-07

    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.

  17. 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.

  18. 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

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

    PubMed

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

    2014-02-01

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

  20. 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.

  1. 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%).

  2. 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.

  3. 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

    2015-02-02

    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.

  4. Isolation, characterization and biological evaluation of jellyfish collagen for use in biomedical applications.

    PubMed

    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.

  5. [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.

  6. Target organ identification of jellyfish envenomation using systemic and integrative analyses in anesthetized dogs.

    PubMed

    Kang, Changkeun; Kim, Young Ki; Lee, Hyunkyoung; Cha, Mijin; Sohn, Eun-Tae; Jung, Eun-Sun; Song, Chiyoun; Kim, Minkyung; Lee, Hee Chun; Kim, Jong-Shu; Hwang, Jin-Yong; Yoon, Won Duk; Kim, Euikyung

    2011-01-01

    Proper treatment of jellyfish envenomed patients can be successfully achieved only from an understanding of the overall functional changes and alterations in physiological parameters under its envenomation. The majority of previous investigations on jellyfish venoms have covered only a couple of parameters at a time. Unlike most other fragmentary jellyfish studies, we employed an integrative toxicological approach, including hemodynamics, clinical chemistry and hematology analyses, using N. nomurai jellyfish venom (NnV) in dogs. After the baseline measurements for mean arterial pressure (MAP), cardiac output (CO) and heart rate (HR), NnV was intravenously administered to the dogs at doses of 0.1 or 0.3mg/kg body weight. The dogs showed significant decreases in MAP (-27.4±3.7 and -48.1±9.9 mmHg), CO (-1.1±0.1 L/min and -1.0±0.2 L/min), and HR (-4.5±0.3 and -9.9±3.1 beats/min) comparing with the respective baseline controls. The onset of systemic hypotension and bradycardia occurred within 1 min of NnV injection and they lasted for 1-35 min, depending on the NnV doses. Interestingly, serum biochemical analyses of envenomed dogs exhibited dramatic increases of alkaline phosphatase (ALP), creatine phosphokinase (CPK), alanine aminotransferase (ALT) and aspartate aminotransferase (AST), indicating its possible target organs. In conclusion, we have demonstrated simultaneously, for the first time, the multiple organ toxicities (cardiotoxic, myotoxic and hepatotoxic) of a scyphozoan jellyfish venom. Based on these results, an integrative toxinological approach using dogs appears to be effective in predicting jellyfish venom toxicities and designing their therapeutic strategies. We expect this method can be applied to other jellyfish venom research as well.

  7. 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.

  8. 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

  9. 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

  10. 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

  11. Environmental control of phase transition and polyp survival of a massive-outbreaker jellyfish.

    PubMed

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

    2010-11-03

    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.

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

    PubMed

    Hoover, Alexander; Miller, Laura

    2015-06-07

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

  13. 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

  14. 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

  15. 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

  16. 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.

  17. 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.

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

    PubMed Central

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

    2017-01-01

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

  19. Protective Effect of Tetracycline against Dermal Toxicity Induced by Jellyfish Venom

    PubMed Central

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

    2013-01-01

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

  20. 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

  1. 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

  2. Pore Water Pumping by Upside-Down Jellyfish

    NASA Astrophysics Data System (ADS)

    Gaddam, Manikantam; Santhanakrishnan, Arvind

    2016-11-01

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

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

    PubMed

    Ristroph, Leif; Childress, Stephen

    2014-03-06

    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.

  4. 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.

  5. Box Jellyfish Alatina alata Has a Circumtropical Distribution.

    PubMed

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

    2016-10-01

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

  6. 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.

  7. 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

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

    NASA Astrophysics Data System (ADS)

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

    2017-03-01

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

  9. 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

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

    PubMed

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

    2014-12-07

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

  11. A bio-inspired bell kinematics design of a jellyfish robot using ionic polymer metal composites actuators

    NASA Astrophysics Data System (ADS)

    Najem, Joseph; Leo, Donald J.

    2012-04-01

    This paper presents the re-creation of the bell deformation cycle of the Aequorea victoria jellyfish. It focuses on the design, fabrication, and characterization of the bio-inspired bell kinematics of an IPMC actuated robotic jellyfish. The shape and bell kinematics of this underwater vehicle are based on the Aequorea victoria jellyfish. This medusa is chosen as a model system based on a comparative bell kinematics study that is conducted among different jellyfish species. Aequorea victoria is known by its low swimming frequency, small bell deformation, and high Froude efficiency (95%). Different methods of implementing the actuators underneath the bell with smaller IPMC actuators are investigated to replicate the natural jellyfish's bell deformation. Results demonstrates that proper placement of the IPMC actuators results in bell configuration that more accurately represents the deformation properties of the natural jellyfish. Smaller IPMC actuators are used to achieve the desired deformation and thus the power consumption is reduced by 70% compared to previous generations. A biomimetic jellyfish robot prototype is built, and its ability to swim and produce thrust with smaller IPMC actuators is shown. The robot swam with four actuators swam at an average speed 0.77 mm/s and consumed 0.7 W. When eight actuators were used the average speed increased to 1.5 mm/s with a power consumption of 1.14 W.

  12. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2017-02-01

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

  14. [Effects of macro-jellyfish abundance dynamics on fishery resource structure in the Yangtze River estuary and its adjacent waters].

    PubMed

    Shan, Xiu-Juan; Zhuang, Zhi-Meng; Jin, Xian-Shi; Dai, Fang-Qun

    2011-12-01

    Based on the bottom trawl survey data in May 2007 and May and June 2008, this paper analyzed the effects of the abundance dynamics of macro-jellyfish on the species composition, distribution, and abundance of fishery resource in the Yangtze River estuary and its adjacent waters. From May 2007 to June 2008, the average catch per haul and the top catch per haul of macro-jellyfish increased, up to 222.2 kg x h(-1) and 1800 kg x h(-1) in June 2008, respectively. The macro-jellyfish were mainly distributed in the areas around 50 m isobath, and not beyond 100 m isobath where was the joint front of the coastal waters of East China Sea, Yangtze River runoff, and Taiwan Warm Current. The main distribution area of macro-jellyfish in June migrated northward, as compared with that in May, and the highest catches of macro-jellyfish in May 2007 and May 2008 were found in the same sampling station (122.5 degrees E, 28.5 degrees N). In the sampling stations with higher abundance of macro-jellyfish, the fishery abundance was low, and the fishery species also changed greatly, mainly composed by small-sized species (Trachurus japonicus, Harpadon nehereus, and Acropoma japonicum) and pelagic species (Psenopsis anomala, Octopus variabilis) and Trichiurus japonicus, and P. anomala accounted for 23.7% of the total catch in June 2008. Larimichthys polyactis also occupied higher proportion of the total catch in sampling stations with higher macro-jellyfish abundance, but the demersal species Lophius litulon was not found, and a few crustaceans were collected. This study showed that macro-jellyfish had definite negative effects on the fishery community structure and abundance in the Yangtze River estuary fishery ecosystem, and further, changed the energy flow patterns of the ecosystem through cascading trophic interactions. Therefore, macro-jellyfish was strongly suggested to be an independent ecological group when the corresponding fishery management measures were considered.

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

    PubMed Central

    Cheng, Xiaochen; Liu, Chenguang

    2017-01-01

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

  16. Geographic patterns of fishes and jellyfish in Puget Sound surface waters

    USGS Publications Warehouse

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

    2012-01-01

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

  17. 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

  18. 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

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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

  4. 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.

  5. 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

  6. 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

  7. A novel protein toxin from the deadly box jellyfish (Sea Wasp, Habu-kurage) Chiropsalmus quadrigatus.

    PubMed

    Nagai, Hiroshi; Takuwa-Kuroda, Kyoko; Nakao, Masahiro; Oshiro, Naomasa; Iwanaga, Setsuko; Nakajima, Terumi

    2002-01-01

    The deadly box jellyfish (Sea Wasp, Habu-kurage in Japanese) Chiropsalmus quadrigatus Haeckel (Cubozoa) is distributed widely in the tropical Pacific region. In Japan, three fatal cases due to stings from this species have been reported officially. We successfully isolated C. quadrigatus toxin-A (CqTX-A, 44 kDa), a major proteinaceous toxin, for the first time, from the nematocysts of C. quadrigatus. CqTX-A showed lethal toxicity to crayfish when administered via intraperitoneal injection (LD50 = 80 microg/kg) and hemolytic activity toward 0.8% sheep red blood cells (ED50 = 160 ng/ml). Furthermore, we sequenced the cDNA encoding CqTX-A. The deduced amino acid sequence of CqTX-A (462 amino acids) showed 25.2% and 21.6% sequence similarity to Carybdea rastoni toxins (CrTXs) and Carybdea alata toxin-A (CrTX-A), respectively, which are Cubozoan jellyfish toxins.

  8. 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.

  9. Jellyfish aggregations and leatherback turtle foraging patterns in a temperate coastal environment.

    PubMed

    Houghton, Jonathan D R; Doyle, Thomas K; Wilson, Mark W; Davenport, John; Hays, Graeme C

    2006-08-01

    Leatherback turtles (Dermochelys coriacea) are obligate predators of gelatinous zooplankton. However, the spatial relationship between predator and prey remains poorly understood beyond sporadic and localized reports. To examine how jellyfish (Phylum Cnidaria: Orders Semaeostomeae and Rhizostomeae) might drive the broad-scale distribution of this wide ranging species, we employed aerial surveys to map jellyfish throughout a temperate coastal shelf area bordering the northeast Atlantic. Previously unknown, consistent aggregations of Rhizostoma octopus extending over tens of square kilometers were identified in distinct coastal "hotspots" during consecutive years (2003-2005). Examination of retrospective sightings data (>50 yr) suggested that 22.5% of leatherback distribution could be explained by these hotspots, with the inference that these coastal features may be sufficiently consistent in space and time to drive long-term foraging associations.

  10. 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.

  11. Pentaplex PCR as screening assay for jellyfish species identification in food products.

    PubMed

    Armani, Andrea; Giusti, Alice; Castigliego, Lorenzo; Rossi, Aurelio; Tinacci, Lara; Gianfaldoni, Daniela; Guidi, Alessandra

    2014-12-17

    Salted jellyfish, a traditional food in Asian Countries, is nowadays spreading on the Western markets. In this work, we developed a Pentaplex PCR for the identification of five edible species (Nemopilema nomurai, Rhopilema esculentum, Rhizostoma pulmo, Pelagia noctiluca, and Cotylorhiza tuberculata), which cannot be identified by a mere visual inspection in jellyfish products sold as food. A common degenerated forward primer and five specie-specific reverse primers were designed to amplify COI gene regions of different lengths. Another primer pair targeted the 28SrRNA gene and was intended as common positive reaction control. Considering the high level of degradation in the DNA extracted from acidified and salted products, the maximum length of the amplicons was set at 200 bp. The PCR was developed using 66 reference DNA samples. It gave successful amplifications in 85.4% of 48 ready to eat products (REs) and in 60% of 30 classical salted products (CPs) collected on the market.

  12. 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.

  13. 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.

  14. Jellyfish mucin may have potential disease-modifying effects on osteoarthritis

    PubMed Central

    2009-01-01

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

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

    PubMed

    Hamlet, Christina L; Miller, Laura A

    2012-11-01

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

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

    PubMed

    Montgomery, Louise; Seys, Jan; Mees, Jan

    2016-07-08

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

  17. 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

  18. 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.

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

    PubMed

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

    2015-01-01

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

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

    NASA Astrophysics Data System (ADS)

    Xu, Nicole; Dabiri, John

    2016-11-01

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

  1. Lessons learned from the jellyfish: Fluid transport at intermediate Reynolds numbers

    NASA Astrophysics Data System (ADS)

    Nawroth, Janna; Dabiri, John

    2011-11-01

    Biologically inspired hydrodynamic propulsion and maneuvering strategies promise the advancement of medical implants and novel robotic tools. We have chosen juvenile jellyfish as a model system for investigating fluid dynamics and morphological properties underlying fluid transport by an elastic system 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 a synthetic jellyfish, that is, a rhythmically actuated elastomer capable of generating efficient feeding and propulsion currents. The main challenges here are (1) to derive a body shape and deformation suitable for effective fluid transport under physiological fluid conditions, (2) to understand the mechanical properties of actuator and elastomer to derive 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.

  2. The in vivo cardiovascular effects of an Australasian box jellyfish (Chiropsalmus sp.) venom in rats.

    PubMed

    Ramasamy, Sharmaine; Isbister, Geoffrey K; Seymour, Jamie E; Hodgson, Wayne C

    2005-03-01

    Using a new technique to extract venom from the nematocysts of jellyfish, the in vivo cardiovascular effects of Chiropsalmus sp. venom were investigated in anaesthetized rats. Chiropsalmus sp. venom (150 microg/kg, i.v.) produced a transient hypertensive response (44+/-4 mmHg; n=6) followed by hypotension and cardiovascular collapse. Concurrent artificial respiration or pretreatment with Chironex fleckeri antivenom (AV, 3000 U/kg, i.v.) did not have any effect on the venom-induced hypertensive response nor the subsequent cardiovascular collapse. The cardiovascular response of animals receiving venom after the infusion of MgSO4 (50-70 mM @ 0.25 ml/min, i.v.; n=5) alone, or in combination with AV (n=5), was not significantly different from rats receiving venom alone. Prior administration of prazosin (50 microg/kg, i.v.; n=4) or ketanserin (1 mg/kg, i.v.; n=4) did not significantly attenuate the hypertensive response nor prevent the cardiovascular collapse induced by venom (50 microg/kg, i.v.). In contrast to previous work examining C. fleckeri venom, administration of AV alone, or in combination with MgSO4, was not effective in preventing cardiovascular collapse following the administration of Chiropsalmus sp. venom. This indicates that the venom of the two related box jellyfish contain different lethal components and highlights the importance of species identification prior to initiating treatment regimes following jellyfish envenoming.

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

    PubMed

    Reynolds, Andy M

    2014-10-06

    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

  4. 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

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

    PubMed

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

    2014-01-01

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

  6. 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

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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

  12. 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.

  13. 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.

  14. 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.

  15. 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

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

    PubMed

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

    2013-09-01

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

  17. Cubozoan jellyfish: an Evo/Devo model for eyes and other sensory systems.

    PubMed

    Piatigorsky, Joram; Kozmik, Zbynek

    2004-01-01

    Cnidaria are the most basal phylum containing a well-developed visual system located on specialized sensory structures (rhopalia) with eyes and statocyts. We have been exploring the cubozoan jellyfish, Tripedalia cystophora. In addition to containing simple photoreceptive ocelli, each rhopalium in Tridedalia has a large and small complex, camera-type eye with a cellular lens containing three distinct families of crystallins which apparently serve non-lenticular functions. Thus, Tridpedalia recruited crystallins by a gene sharing strategy as have mollusks and vertebrates. Tripedalia has a single Pax gene, PaxB, which encodes a structural and functional Pax 2/5/8-like paired domain as well as an octapeptide and Pax6-like homeodomain. PaxB binds to and activates Tripedalia crystallin promoters (especially J3-crystallin) and the Drosophila rhodopsin rh6 gene in transfection tests and induces ectopic eyes in Drosophila. In situ hybridization showed that PaxB and crystallin genes are expressed in the lens, retina and statocysts. We suggest from these results that an ancestral PaxB gene was a primordial gene in eye evolution and that eyes and ears (mechanoreceptors) may have had a common evolutionary origin. Thus, the numerous structural and molecular features of Tridpalia rhopalia indicate that ancient cubozoan jellyfish are fascinating models for evo/devo insights into eyes and other sensory systems.

  18. 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

  19. Ecosystem engineers in the pelagic realm: alteration of habitat by species ranging from microbes to jellyfish.

    PubMed

    Breitburg, Denise L; Crump, Byron C; Dabiri, John O; Gallegos, Charles L

    2010-08-01

    Ecosystem engineers are species that alter the physical environment in ways that create new habitat or change the suitability of existing habitats for themselves or other organisms. In marine systems, much of the focus has been on species such as corals, oysters, and macrophytes that add physical structure to the environment, but organisms ranging from microbes to jellyfish and finfish that reside in the water column of oceans, estuaries, and coastal seas alter the chemical and physical environment both within the water column and on the benthos. By causing hypoxia, changing light regimes, and influencing physical mixing, these organisms may have as strong an effect as species that fall more clearly within the classical category of ecosystem engineer. In addition, planktonic species, such as jellyfish, may indirectly alter the physical environment through predator-mediated landscape structure. By creating spatial patterns of habitats that vary in their rates of mortality due to predation, planktonic predators may control spatial patterns and abundances of species that are the direct creators or modifiers of physical habitat.

  20. 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.

  1. 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.

  2. 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.

  3. 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

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

    PubMed

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

    2015-01-01

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

  5. 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.

  6. 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

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

    PubMed

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

    2011-01-01

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

  8. 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.

  9. 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

    2015-09-24

    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.

  10. 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

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

    PubMed

    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.

  12. 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.

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

    PubMed

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

    2014-05-07

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

  14. 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.

  15. Novel proteinaceous toxins from the box jellyfish (sea wasp) Carybdea rastoni.

    PubMed

    Nagai, H; Takuwa, K; Nakao, M; Ito, E; Miyake, M; Noda, M; Nakajima, T

    2000-08-28

    During summer and autumn, the box jellyfish (sea wasp) Carybdea rastoni is one of the most bothersome stinging pests to swimmers and bathers on the Japanese coast. Two labile but potent hemolytic toxins from the tentacles of Carybdea rastoni were isolated in their active forms using newly developed purification methods. The molecular masses of the isolated C. rastoni toxin-A and toxin-B (CrTX-A and CrTX-B) are 43 and 46 kDa, respectively, as calculated from SDS-PAGE. In the present study, we sequenced the full-length cDNA (1600 bp), which encodes both CrTX-A and CrTX-B. The deduced 450 amino acid sequence of the CrTXs, showed no significant homology with any known protein. This report presents the first complete sequence of a proteinaceous jellyfish toxin. Furthermore, it was revealed that CrTX-A was primarily localized in the nematocyst, whereas CrTX-B was detected only in the tentacle. Because the nematocyst is the organ responsible for the cnidarian sting, the remainder of the study focused on the toxicity of CrTX-A. We found that CrTX-A was fatally toxic to mice at 20 microg/kg (i.v.) and crayfish at 5 microg/kg (i.p.). Subcutaneously injected CrTX-A (0.1 microg) caused inflammation of mouse skin. These results showed that CrTX-A is responsible for the cutaneous inflammation observed in humans stung by C. rastoni.

  16. Bioluminescence of Aequorea macrodactyla, a common jellyfish species in the East China Sea.

    PubMed

    Xia, Ning-Shao; Luo, Wen-Xin; Zhang, Jun; Xie, Xiao-Yan; Yang, Hai-Jie; Li, Shao-Wei; Chen, Ming; Ng, Mun-Hon

    2002-03-01

    Studies of the bioluminescent mechanisms of jellyfish have been mainly confined to one species, Aequorea victoria. We describe the luminescent system of another species, Aequorea macrodactyla, which is commonly found in the warmer waters on the coastal region of East China Sea. The luminescent system of this species consists of a green fluorescent protein (GFP) and one or more aequorins. The GFP gene is 1042 bp. It encompasses a coding sequence of 717 bp organized as 3 exons, and it is predicted to specify a 27-kDa peptide, which shares 80% amino acid sequence identity with the GFP of A. victoria. The entire coding sequence was cloned into the pTO-T7 expression vector and expressed in Escherichia coli. Compared with GFP of A. victoria, the purified expressed protein exhibited an excitation peak at a higher wavelength of 476 nm and an emission peak at a lower wavelength of 496 nm, with a higher quantum yield of 1.0. The other photoprotein, aequorin, is encoded in a single open reading frame of 585 bp specifying a 23-kDa apoprotein. The gene was cloned in to the same expression vector and expressed in E. coli. The activity of the photoprotein was reconstituted by incubating the expressed apoprotein with coelenterazine f. In the presence of Ca(2+) the reconstituted aequorin exhibits an emission peak at 470 nm. The kinetics of regeneration and the photoactivities of the reconstituted aequorins of the 2 species of jellyfish are similar. Nevertheless, Aequorea macrodactyla is expected to appear brighter and more "blue" than Aequorea victorea because of the differences in the photoactivity of their GFPs.

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

    PubMed

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

    2009-07-01

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

  18. 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.

  19. 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.

  20. Accumulation of nanoparticles in "jellyfish" mucus: a bio-inspired route to decontamination of nano-waste.

    PubMed

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

    2015-06-22

    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.

  1. 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.

  2. 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

  3. 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

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

    NASA Astrophysics Data System (ADS)

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

    2017-03-01

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

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

    PubMed

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

    2010-03-01

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

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

    PubMed

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

    2014-03-01

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

  7. Jellyfish stings

    MedlinePlus

    ... of Medicine, University of Hawaii at Manoa, Honolulu, HI. Jacob L. Heller, MD, MHA, Emergency Medicine, Virginia ... A.M. is also a founding member of Hi-Ethics and subscribes to the principles of the ...

  8. 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)

  9. 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

  10. 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

  11. 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.

  12. The state of water in living systems: from the liquid to the jellyfish.

    PubMed

    Henry, M

    2005-12-14

    The status of water in living systems is reviewed both from philosophical and scientific viewpoints. Starting from antique Mediterranean civilizations (Sumerian, Egyptian, Hebrew, Greek), a world trip is proposed through Norse myths, Siberian Shamanism, Hinduism, Taoism, Buddhism, Shinto, Mayan, Aztec, Inca, Aboriginal and African philosophies in order to convince that all humans share the same qualitative idea that water was a pre-requisite for life apparition. The quantitative aspect of the problem is further analyzed at the light of the scientific contributions from two leading scientists: R.A. Gortner and E.T. Jaynes. With Gortner's work it is demonstrated using the concrete example of the Jellyfish submitted at a Faraday discussion held in London in 1930, how a paradigm shift has occurred in the thirties concerning the status of bound water in the living cell. With Jaynes' work, the disastrous consequences of the entrenchment of diffusion theory in biology are critically examined and the exact meaning of the second law of thermodynamics for biological systems is given using the concrete example of muscle contraction. In conclusion, the importance of distinguishing between an ontological and epistemological level of knowledge is stressed and suggestions for reconciling scientific and philosophical approaches are given.

  13. To flap or not to flap: a discussion between a fish and a jellyfish

    NASA Astrophysics Data System (ADS)

    Martin, Nathan; Roh, Chris; Idrees, Suhail; Gharib, Morteza

    2016-11-01

    Fish and jellyfish are known to swim by flapping and by periodically contracting respectively, but which is the more effective propulsion mechanism? In an attempt to answer this question, an experimental comparison is made between simplified versions of these motions to determine which generates the greatest thrust for the least power. The flapping motion is approximated by pitching plates while periodic contractions are approximated by clapping plates. A machine is constructed to operate in either a flapping or a clapping mode between Reynolds numbers 1,880 and 11,260 based on the average plate tip velocity and span. The effect of the total sweep angle, total sweep time, plate flexibility, and duty cycle are investigated. The average thrust generated and power required per cycle are compared between the two modes when their total sweep angle and total sweep time are identical. In general, operating in the clapping mode required significantly more power to generate a similar thrust compared to the flapping mode. However, modifying the duty cycle for clapping caused the effectiveness to approach that of flapping with an unmodified duty cycle. These results suggest that flapping is the more effective propulsion mechanism within the range of Reynolds numbers tested. This work was supported by the Charyk Bio-inspired Laboratory at the California Institute of Technology, the National Science Foundation Graduate Research Fellowship under Grant No. DGE-1144469, and the Summer Undergraduate Research Fellowships program.

  14. Subcellular calcium measurements in mammalian cells using jellyfish photoprotein aequorin-based probes.

    PubMed

    Bonora, Massimo; Giorgi, Carlotta; Bononi, Angela; Marchi, Saverio; Patergnani, Simone; Rimessi, Alessandro; Rizzuto, Rosario; Pinton, Paolo

    2013-11-01

    The jellyfish Aequorea victoria produces a 22-kDa protein named aequorin that has had an important role in the study of calcium (Ca(2+)) signaling. Aequorin reacts with Ca(2+) via oxidation of the prosthetic group, coelenterazine, which results in emission of light. This signal can be detected by using a special luminescence reader (called aequorinometer) or luminescence plate readers. Here we describe the main characteristics of aequorin as a Ca(2+) probe and how to measure Ca(2+) in different intracellular compartments of animal cells (cytosol, different mitochondrial districts, nucleus, endoplasmic reticulum (ER), Golgi apparatus, peroxisomes and subplasma-membrane cytosol), ranging from single-well analyses to high-throughput screening by transfecting animal cells using DNA vectors carrying recombinant aequorin chimeras. The use of aequorin mutants and modified versions of coelenterazione increases the range of calcium concentrations that can be recorded. Cell culture and transfection takes ∼3 d. An experiment including signal calibration and the subsequent analyses will take ∼1 d.

  15. Control of swimming in the hydrozoan jellyfish Aequorea victoria: subumbrellar organization and local inhibition.

    PubMed

    Satterlie, Richard A

    2008-11-01

    The subumbrella of the hydrozoan jellyfish Aequorea victoria (previously classified as Aequorea aequorea) is divided by numerous radial canals and attached gonads, so the subumbrellar musculature is partitioned into subumbrellar segments. The ectoderm of each segment includes two types of muscle: smooth muscle with a radial orientation, used for local (feeding and righting) and widespread (protective) radial responses, and striated muscle with a circular orientation which produces swim contractions. Two subumbrellar nerve nets were found, one of which stained with a commercial antibody produced against the bioactive peptide FMRFamide. Circular muscle cells produce a single, long-duration action potential with each swim, triggered by a single junctional potential. In addition, the circular cells are electrically coupled so full contractions require both electrotonic depolarization from adjacent cells and synaptic input from a subumbrellar nerve net. The radial cells, which form a layer superficial to the circular cells, are also activated by a subumbrellar nerve net, and produce short-duration action potentials. The radial muscle cells are electrically coupled to one another. No coupling exists between the two muscle layers. Spread of excitation between adjacent segments is decremental, and nerve net-activated junctional potentials disappear during local inhibition of swimming (such as with a radial response). Variable swim contractions are controlled by a combination of synaptic input from the motor network of the inner nerve ring, synaptic input from a subumbrellar nerve net, and electrotonic depolarization from adjacent, active muscle cells.

  16. 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.

  17. Cardiovascular effects of Nemopilema nomurai (Scyphozoa: Rhizostomeae) jellyfish venom in rats.

    PubMed

    Kim, Euikyung; Lee, Seunghwan; Kim, Jong-Shu; Yoon, Won Duk; Lim, Donghyun; Hart, Andrew J; Hodgson, Wayne C

    2006-12-15

    Over the past few years, populations of the giant jellyfish Nemopilema nomurai (Scyphozoa: Rhizostomeae) have increased dramatically in the waters of China, Korea, and Japan without any definitive reason. This has resulted in severe damage to fisheries in the areas. During a pilot study, we observed that the venom of N. nomurai produced a functional cardiac depression in mice. However, the mechanism of action was not examined. In the present study, we investigated the cardiovascular effects of nematocyst-derived venom from N. nomurai in anesthetized rats. Venom (0.1-2.4 mg protein/kg, i.v.) produced dose-dependent hypotension (65+/-12% of initial at a cumulative dose of 3 mg/kg) and bradycardia (80+/-5% of initial at a cumulative dose of 3 mg/kg). At the highest dose, this was characterized by a transient decrease in blood pressure (phase 1) followed by a return to basal level and then a slower decrease in blood pressure (phase 2). Venom also produced a decrease in rate and force of contraction in the rat isolated atria. Interestingly, venom induced a contraction of isolated aortic rings which was blocked by felodipine but not by prazosin, suggesting the contraction is mediated by calcium channel activation. These results suggest that the negative inotropic and chronotropic effects of the venom of N. nomurai may be due to a direct effect on the heart.

  18. ACE Inhibitory and Antioxidant Activities of Collagen Hydrolysates from the Ribbon Jellyfish (Chrysaora sp.)

    PubMed Central

    Latiff, Aishah Abd; Gan, Chee-Yuen; Abedin, Md. Zainul; Alias, Abd Karim

    2014-01-01

    Summary Collagen isolated from the ribbon jellyfish (Chrysaora sp.) was hydrolysed using three different proteases (i.e. trypsin, alcalase and Protamex) to obtain bioactive peptides. Angiotensin-I-converting enzyme (ACE) inhibitory activity and antioxidant activities (i.e. ferric reducing antioxidant power (FRAP) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity) of the peptides were measured and compared, and the effect of the duration of hydrolysis on the bioactivity (ACE inhibitory and antioxidant activities) of peptides was also evaluated. FRAP activity was the highest in Protamex-induced (25–27 mM) and trypsin-induced hydrolysates (24–26 mM) at 7 and 9 h, respectively. Conversely, hydrolysates produced by trypsin for 1 and 3 h showed the highest DPPH radical scavenging activities (94 and 92%, respectively). Trypsin-induced hydrolysates (at 3 h) also showed the highest ACE inhibitory activity (89%). The peptide sequences with the highest activities were identified using tandem mass spectrometry, and the results show that the hydrolysates had a high content of hydrophobic amino acids as well as unique amino acid sequences, which likely contribute to their biological activities. PMID:27904323

  19. 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.

  20. A pharmacological investigation of the venom extract of the Australian box jellyfish, Chironex fleckeri, in cardiac and vascular tissues.

    PubMed

    Hughes, Richard J A; Angus, James A; Winkel, Kenneth D; Wright, Christine E

    2012-02-25

    The pharmacology of Australian box jellyfish, Chironex fleckeri, unpurified (crude) nematocyst venom extract (CVE) was investigated in rat isolated cardiac and vascular tissues and in anaesthetised rats. In small mesenteric arteries CVE (0.01-30 μg/ml) caused contractions (EC(50) 1.15±0.19 μg/ml) that were unaffected by prazosin (0.1 μM), bosentan (10 μM), CGRP(8-37) (1 μM) or tetrodotoxin (1 μM). Box jellyfish antivenom (5-92.6 units/ml) caused rightward shifts of the CVE concentration-response curve with no change in the maximum. In the presence of l-NAME (100 μM) the sensitivity and maximum response to CVE were increased, whilst MgSO(4) (6 mM) decreased both parameters. CVE (1-10 μg/ml) caused inhibition of the contractile response to electrical sympathetic nerve stimulation. Left atrial responses to CVE (0.001-30 μg/ml) were bi-phasic, composed of an initial positive inotropy followed by a marked negative inotropy and atrial standstill. CVE (0.3 μg/ml) elicited a marked decrease in right atrial rate followed by atrial standstill at 3 μg/ml. These responses were unaffected by 1 μM of propranolol, atropine or CGRP(8-37). Antivenom (54 and 73 units/ml) caused rightward shifts of the CVE concentration-response curve and prevented atrial standstill in left and right atria. The effects of CVE do not appear to involve autonomic nerves, post-synaptic α(1)- or β(1)-adrenoceptors, or muscarinic, endothelin or CGRP receptors, but may occur through direct effects on the cardiac and vascular muscle. Box jellyfish antivenom was effective in attenuating CVE-induced responses in isolated cardiac and vascular tissues.

  1. 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.

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

    PubMed

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

    2010-08-10

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

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

    PubMed

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

    2014-12-15

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

  4. Setting the Pace: New Insights into Central Pattern Generator Interactions in Box Jellyfish Swimming

    PubMed Central

    Stöckl, Anna Lisa; Petie, Ronald; Nilsson, Dan-Eric

    2011-01-01

    Central Pattern Generators (CPGs) produce rhythmic behaviour across all animal phyla. Cnidarians, which have a radially symmetric nervous system and pacemaker centres in multiples of four, provide an interesting comparison to bilaterian animals for studying the coordination between CPGs. The box jellyfish Tripedalia cystophora is remarkable among cnidarians due to its most elaborate visual system. Together with their ability to actively swim and steer, they use their visual system for multiple types of behaviour. The four swim CPGs are directly regulated by visual input. In this study, we addressed the question of how the four pacemaker centres of this radial symmetric cnidarian interact. We based our investigation on high speed camera observations of the timing of swim pulses of tethered animals (Tripedalia cystophora) with one or four rhopalia, under different simple light regimes. Additionally, we developed a numerical model of pacemaker interactions based on the inter pulse interval distribution of animals with one rhopalium. We showed that the model with fully resetting coupling and hyperpolarization of the pacemaker potential below baseline fitted the experimental data best. Moreover, the model of four swim pacemakers alone underscored the proportion of long inter pulse intervals (IPIs) considerably. Both in terms of the long IPIs as well as the overall swim pulse distribution, the simulation of two CPGs provided a better fit than that of four. We therefore suggest additional sources of pacemaker control than just visual input. We provide guidelines for future research on the physiological linkage of the cubozoan CPGs and show the insight from bilaterian CPG research, which show that pacemakers have to be studied in their bodily and nervous environment to capture all their functional features, are also manifest in cnidarians. PMID:22073288

  5. 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.

  6. 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.

  7. Mitochondrial genome of the freshwater jellyfish Craspedacusta sowerbyi and phylogenetics of Medusozoa.

    PubMed

    Zou, Hong; Zhang, Jin; Li, Wenxiang; Wu, Shangong; Wang, Guitang

    2012-01-01

    The 17,922 base pairs (bp) nucleotide sequence of the linear mitochondrial DNA (mtDNA) molecule of the freshwater jellyfish Craspedacusta sowerbyi (Hydrozoa, Trachylina, Limnomedusae) has been determined. This sequence exhibits surprisingly low A+T content (57.1%), containing genes for 13 energy pathway proteins, a small and a large subunit rRNAs, and methionine and tryptophan tRNAs. Mitochondrial ancestral medusozoan gene order (AMGO) was found in the C. sowerbyi, as those found in Cubaia aphrodite (Hydrozoa, Trachylina, Limnomedusae), discomedusan Scyphozoa and Staurozoa. The genes of C. sowerbyi mtDNA are arranged in two clusters with opposite transcriptional polarities, whereby transcription proceeds toward the ends of the DNA molecule. Identical inverted terminal repeats (ITRs) flank the ends of the mitochondrial DNA molecule, a characteristic typical of medusozoans. In addition, two open reading frames (ORFs) of 354 and 1611 bp in length were found downstream of the large subunit rRNA gene, similar to the two ORFs of ORF314 and polB discovered in the linear mtDNA of C. aphrodite, discomedusan Scyphozoa and Staurozoa. Phylogenetic analyses of C. sowerbyi and other cnidarians were carried out based on both nucleotide and inferred amino acid sequences of the 13 mitochondrial energy pathway genes. Our working hypothesis supports the monophyletic Medusozoa being a sister group to Octocorallia (Cnidaria, Anthozoa). Within Medusozoa, the phylogenetic analysis suggests that Staurozoa may be the earliest diverging class and the sister group of all other medusozoans. Cubozoa and coronate Scyphozoa form a clade that is the sister group of Hydrozoa plus discomedusan Scyphozoa. Hydrozoa is the sister group of discomedusan Scyphozoa. Semaeostomeae is a paraphyletic clade with Rhizostomeae, while Limnomedusae (Trachylina) is the sister group of hydroidolinans and may be the earliest diverging lineage among Hydrozoa.

  8. Isolation and characterization of a novel protein toxin from the Hawaiian box jellyfish (sea wasp) Carybdea alata.

    PubMed

    Nagai, H; Takuwa, K; Nakao, M; Sakamoto, B; Crow, G L; Nakajima, T

    2000-08-28

    The box jellyfish (sea wasp) Carybdea alata Reynaud, 1830 (Cubozoa) is distributed widely in the tropics. The sting of C. alata causes severe pain and cutaneous inflammation in humans. We successfully isolated C. alata toxin-A (CaTX-A, 43 kDa) and -B (CaTX-B, 45 kDa) for the first time from the tentacle of C. alata collected at a site along the Hawaiian shore. The experimental results showed that CaTX-A, but not CaTX-B, is present in the nematocyst, the organ responsible for stinging. Both CaTX-A and -B showed potent hemolytic activity, with CaTX-A being lethally toxic to crayfish when administered via intraperitoneal injection. Furthermore, we sequenced the cDNA encoding CaTX-A. The deduced amino acid sequence of CaTX-A (463 amino acids) showed 43.7% homology to Carybdea rastoni toxins (CrTXs) but not with any other known proteins. Therefore, these jellyfish toxins potentially represent a novel class of bioactive proteins. Secondary structure analysis of CaTX-A and CrTXs suggested the presence of amphiphilic alpha-helices, which are also seen in several known hemolytic or cytolytic protein toxins, including peptide toxins.

  9. 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.

  10. 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

  11. 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.

  12. 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.

  13. 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.

  14. Predicting aqueous copper and zinc accumulation in the upside-down jellyfish Cassiopea maremetens through the use of biokinetic models.

    PubMed

    Templeman, Michelle A; Kingsford, Michael J

    2015-07-01

    Jellyfish have a demonstrated capability to accumulate metals within their tissues, but to date, there have been no quantitative assessments of accumulation and retention rates and patterns. Bioconcentration patterns of copper and zinc in the upside-down jellyfish Cassiopea maremetens were modelled over a 28-day study (14 days exposure followed by 14 days clearance). C. maremetens accumulated copper over 14 days with the maximum calculated copper concentrations at 33.78 μg g(-1) dry weight and bioconcentrated to 99 times water concentrations. Zinc was also accumulated during the exposure period and retained for longer. The maximum theoretical zinc concentration was 125.1 μg g(-1) dry weight with a kinetic bioconcentration factor of 104. The patterns of uptake and retention were different between the elements. The use of kinetic models provided adequate predictions of aqueous metal uptake and retention in C. maremetens. This species has the capacity to very rapidly absorb measurable metals from short-term water-metal exposure.

  15. 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.

  16. A wake-based correlate of swimming performance and foraging behavior in seven co-occurring jellyfish species.

    PubMed

    Dabiri, J O; Colin, S P; Katija, K; Costello, J H

    2010-04-01

    It is generally accepted that animal-fluid interactions have shaped the evolution of animals that swim and fly. However, the functional ecological advantages associated with those adaptations are currently difficult to predict on the basis of measurements of the animal-fluid interactions. We report the identification of a robust, fluid dynamic correlate of distinct ecological functions in seven jellyfish species that represent a broad range of morphologies and foraging modes. Since the comparative study is based on properties of the vortex wake--specifically, a fluid dynamical concept called optimal vortex formation--and not on details of animal morphology or phylogeny, we propose that higher organisms can also be understood in terms of these fluid dynamic organizing principles. This enables a quantitative, physically based understanding of how alterations in the fluid dynamics of aquatic and aerial animals throughout their evolution can result in distinct ecological functions.

  17. 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.

  18. 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

  19. 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.

  20. Computational comparison of a calcium-dependent jellyfish protein (apoaequorin) and calmodulin-cholesterol in short-term memory maintenance.

    PubMed

    Morrill, Gene A; Kostellow, Adele B; Gupta, Raj K

    2017-03-06

    Memory reconsolidation and maintenance depend on calcium channels and on calcium/calmodulin-dependent kinases regulating protein turnover in the hippocampus. Ingestion of a jellyfish protein, apoaequorin, reportedly protects and/or improves verbal learning in adults and is currently widely advertised for use by the elderly. Apoaequorin is a member of the EF-hand calcium binding family of proteins that includes calmodulin. Calmodulin-1 (148 residues) differs from Apoaequorin (195 residues) in that it contains four rather than three Ca(2+)-binding sites and three rather than four cholesterol-binding (CRAC, CARC) domains. All three cholesterol-binding CARC domains in calmodulin have a high interaction affinity for cholesterol compared to only two high affinity CARC domains in apoaequorin. Both calmodulin and apoaequorin can form dimers with a potential of eight bound Ca(2+) ions and six high affinity-bound cholesterol molecules in calmodulin with six bound Ca(2+) ions and a mixed population of eight cholesterols bound to both CARC and CRAC domains in apoaqueorin. MEMSAT-SVM analysis indicates that both calmodulin and apoaqueorin have a pore-lining region. The Peptide-Cutter algorithm predicts that calmodulin-1 contains 11 trypsin-specific cleavage sites (compared to 21 in apoaqueorin), four of which are potentially blocked by cholesterol and three are within the Ca-binding domains and/or the pore-lining region. Three are clustered between the third and fourth Ca(2+)-binding sites. Only calmodulin pore-lining regions contain Ca(2+) binding sites and as dimers may insert into the plasma membrane of neural cells and act as Ca(2+) channels. In a dietary supplement, bound cholesterol may protect both apoaequorin and calmodulin from proteolysis in the gut as well as facilitate uptake across the blood-brain barrier. Our results suggest that a physiological calmodulin-cholesterol complex, not cholesterol-free jellyfish protein, may better serve as a dietary supplement to

  1. 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

  2. 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.

  3. J1-crystallins of the cubomedusan jellyfish lens constitute a novel family encoded in at least three intronless genes.

    PubMed

    Piatigorsky, J; Horwitz, J; Norman, B L

    1993-06-05

    The transparent cellular eye lens of the jellyfish (Tripedalia cystophora) contains three major proteins called J1-, J2-, and J3-crystallins. Here we have isolated cDNAs encoding three novel 37-kDa J1-crystallin polypeptides (J1A, J1B, and J1C) sharing 84-98% identity in amino acid sequence among themselves. Each polypeptide is encoded in a separate gene lacking introns. In contrast to the striking similarity of the coding regions, the 5'- and 3'-untranslated sequences of the three J1-crystallin mRNAs are completely different, consistent with an ancient duplication of their genes. Thermostability experiments showed that J1-crystallins remain soluble at 50 degrees C, but precipitate at 60 degrees C, suggesting that these major lens proteins are neither heat shock proteins nor unusually heat-resistant as are many vertebrate crystallins. Although J1 mRNAs appear polyadenylated, no typical polyadenylation signal was detected in the cDNAs. Surprisingly, the only obvious similarities among the 5'-flanking regions of the three J1-crystallin genes are putative TATA boxes and several CAAT sequences, consistent with fewer evolutionary constraints on the regulatory sequences than on the coding sequences of these crystallin genes.

  4. 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

  5. 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

    2016-06-09

    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.

  6. 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

  7. Fine structure, histochemistry, and morphogenesis during excystment of the podocysts of the giant jellyfish Nemopilema nomurai (Scyphozoa, Rhizostomeae).

    PubMed

    Ikeda, Hideki; Ohtsu, Kohzoh; Uye, Shin-Ichi

    2011-12-01

    Production of podocysts is the exclusive form of asexual reproduction by polyps of the giant jellyfish Nemopilema nomurai, which has been recurrently blooming in the East Asian seas in the last decade. Podocycts consist of a dome-shaped chitinous capsule with laminated structure that encapsulates a mass of cyst cells filled with granules containing nutrient reserves such as proteins, carbohydrates, and lipids. Mitochondria, rough endoplasmic reticulum, and Golgi complexes are scarce in the cytoplasm of these cells, and the staining reaction for RNA is weak, indicating very low metabolic activity. Podocysts are capable of dormancy for at least 5 years without significant change of internal structure or nutrient reserves. Integrated information about spontaneous and artificially induced metamorphosis suggests that the following processes occur during excystment: (1) nematocyst formation in the internal cell mass, (2) stratification of the cell mass into endoderm and ectoderm, (3) extrusion of the cell mass through a gradual opening of the capsule, (4) formation of primordial polyp mouth and tentacles, and (5) metamorphosis to a polyp. We morphologically confirmed that N. nomurai podocysts have the capacity for long-term dormancy, an ability that should contribute to the periodic nature of the massive blooms of medusae of this species.

  8. 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.

  9. 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.

  10. 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.

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

    PubMed

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

    2016-02-29

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

  12. 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

  13. A numerical study of the effects of bell pulsation dynamics and oral arms on the exchange currents generated by the upside-down jellyfish Cassiopea xamachana.

    PubMed

    Hamlet, Christina; Santhanakrishnan, Arvind; Miller, Laura A

    2011-06-01

    Mathematical and experimental studies of the flows generated by jellyfish have focused primarily on mechanisms of swimming. More recent work has also considered the fluid dynamics of feeding from currents generated during swimming. Here we capitalize on the benthic lifestyle of the upside-down jellyfish (Cassiopea xamachana) to explore the fluid dynamics of feeding uncoupled from swimming. A two-dimensional mathematical model is developed to capture the fundamental characteristics of the motion of the unique concave bell shape. Given the prominence of the oral arms, this structure is included and modeled as a porous layer that perturbs the flow generated by bell contractions. The immersed boundary method is used to solve the fluid-structure interaction problem. Velocity fields obtained from live organisms using digital particle image velocimetry were used to validate the numerical simulations. Parameter sweeps were used to numerically explore the effects of changes in pulse dynamics and the properties of the oral arms independently. Numerical experiments allow the opportunity to examine physical effects and limits within and beyond the biologically relevant range to develop a better understanding of the system. The presence of the prominent oral arm structures in the field of flow increased the flux of new fluid from along the substrate to the bell. The numerical simulations also showed that the presence of pauses between bell expansion and the next contraction alters the flow of the fluid over the bell and through the oral arms.

  14. Stalked jellyfishes (Cnidaria: Staurozoa) of South Africa, with the description of Calvadosia lewisi sp. nov.

    PubMed

    Miranda, Lucília S; Branch, George M; Collins, Allen G; Hirano, Yayoi M; Marques, Antonio C; Griffiths, Charles L

    2017-02-03

    Stalked jellyfishes (Cnidaria: Staurozoa) are cryptic, benthic animals, known mainly from polar and temperate waters of the Northern Hemisphere. We describe a new species, Calvadosia lewisi, from South Africa and review the staurozoan fauna of the region. Three other species are previously known from South Africa: Calvadosia capensis (Carlgren, 1938); Depastromorpha africana Carlgren, 1935; and Lipkea stephensoni Carlgren, 1933, but all of these are known from very few records and have been poorly illustrated and documented to date. We provide brief descriptions and photographic illustrations for each species and a list of local and global geographical records. Two (L. stephensoni and C. lewisi), but possibly three (D. africana), of the four known South African staurozoan species are endemic from South Africa. The new species, images, and extra distributional records presented here greatly improve knowledge of the staurozoan fauna in South Africa and, consequently, of the Southern Hemisphere.

  15. Monodisc strobilation in Japanese giant box jellyfish Morbakka virulenta (Kishinouye, 1910): a strong implication of phylogenetic similarity between Cubozoa and Scyphozoa.

    PubMed

    Toshino, Sho; Miyake, Hiroshi; Ohtsuka, Susumu; Adachi, Aya; Kondo, Yusuke; Okada, Shoma; Hirabayashi, Takeshi; Hiratsuka, Tatsuya

    2015-01-01

    Both sexes of the Japanese giant box jellyfish Morbakka virulenta were collected from the Seto Inland Sea, western Japan in December 2011, in order to observe the developmental processes from polyps to medusae. The medusa production in M. virulenta is up to now a unique process in cubozoans in that it exhibits a form of monodisc strobilation where the polyp is regenerated before the medusa detaches. This mode of medusa production was previously thought to be exclusive to scyphozoans. The general shape of young medusae resembles that of other cubozoans such as Alatina moseri and Copula sivickisi, but is differentiated from these by the short capitate tentacles and the lack of gastric filaments in the stomach. The unique medusa production of M. virulenta highly implies a phylogenetic similarity between cubozoans and scyphozoans.

  16. 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.

  17. The in vivo cardiovascular effects of box jellyfish Chironex fleckeri venom in rats: efficacy of pre-treatment with antivenom, verapamil and magnesium sulphate.

    PubMed

    Ramasamy, Sharmaine; Isbister, Geoffrey K; Seymour, Jamie E; Hodgson, Wayne C

    2004-05-01

    Using a new technique to extract venom from the nematocysts, the efficacy of CSL box jellyfish antivenom (AV) and adjunct therapies, verapamil and magnesium sulfate (MgSO(4)), were investigated against the in vivo cardiovascular effects of Chironex fleckeri venom in anaesthetised rats. C. fleckeri venom (30 microg/kg; i.v.) produced a transient hypertensive response followed by hypotension and cardiovascular collapse within 4 min of administration. Prophylactic treatment of anaesthetised rats with CSL box jellyfish AV (3000 U/kg; i.v.) did not have any effect on the venom-induced pressor response, but prevented cardiovascular collapse in four out of 10 animals. Administration of verapamil (20mM@0.25 ml/min; i.v.) either alone or in combination with AV, did not have any effect on the C. fleckeri venom-induced pressor response nor the consequent hypotension or cardiovascular collapse of animals. However, the administration of verapamil negated the partially protective effects of AV. Concurrent artificial respiration of animals with the above treatments did not attenuate the C. fleckeri venom-induced cardiovascular effects. MgSO(4) (0.05-0.07M@0.25 ml/min; i.v.) alone did not have any effect on the venom-induced pressor response nor the consequent cardiovascular collapse of animals. However, although combined AV and MgSO(4) administration could not inhibit the transient pressor effect following the administration of C. fleckeri venom, it prevented cardiovascular collapse in all animals. We show for the first time, the cardiovascular effects of a C. fleckeri venom sample free of tentacular contamination and the potential of MgSO(4) as an adjunct therapy for the treatment of potentially fatal C. fleckeri envenomings.

  18. Is sleep's 'supreme mystery' unraveling? An evolutionary analysis of sleep encounters no mystery; nor does life's earliest sleep, recently discovered in jellyfish.

    PubMed

    Kavanau, J Lee

    2006-01-01

    Biotelemetry has revealed daily 15-h behavioral sleep periods in a cubomedusan jellyfish, Chironex fleckeri. Its sleep is expected to be phylogenetically most primitive, since jellyfish possess only two germ layers. They belong to the phylum Cnidaria, the 'simplest' multicellular organisms with an organized nervous system. Cubomedusae have a complex visual system with 24 eyes of four different types, each type specialized for a different task. Input to these eyes during visually guided fast-swimming predation requires enormous amounts of neural processing, possibly nearly saturating the capacity of their comparatively simple nervous system. These heavy neural demands may account for the need for fifteen hours of sleep. C. fleckeri is the only animal known for which sleep may be either present or absent, dependent on lifestyle. Limited knowledge of behavior of some other cubomedusae suggests that they also possess this faculty. The finding of sleep in C. fleckeri supports current proposals of sleep's origin and basic function. Evolutionary analyses link sleep to a conflict produced by excessive processing demands on multifunctional neural circuitry for detailed focal vision by complex lensed eyes. The conflict arises between the enormous demands of complex visual analysis and needs for split-second control of actions, on the one hand, and non-urgent processing of memories of ongoing and stored events, on the other. Conflict is resolved by deferring the non-urgent processing to periods of sleep. Without sleep, selection would favor the evolution of circuitry 'dedicated' to single or but few tasks, with corresponding lesser efficiency. Had complex lensed eyes of medusae originated as a consequence of selection for increased mating success of males pursuing females, it could have occurred before the evolution of fast-swimming bilateral (three-germ-layered) prey. But if it was a consequence of selection for increased prey-hunting success, the origin of such eyes

  19. 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.

  20. 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).

  1. 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.

  2. Oxidative stress induced by crude venom from the jellyfish Pelagia noctiluca in neuronal-like differentiated SH-SY5Y cells.

    PubMed

    Morabito, Rossana; Condello, Salvatore; Currò, Monica; Marino, Angela; Ientile, Riccardo; La Spada, Giuseppina

    2012-08-01

    Marine toxins are a suitable research model and their mechanism of action is intriguing and still under debate. Either a pore formation mechanism or oxidative stress phenomena may explain the damage induced by toxins. The effect of crude venom from isolated nematocysts of the jellyfish Pelagia noctiluca on neuronal-like cells derived from human neuroblastoma SH-SY5Y has been here studied. To prove the possible oxidative stress events, cell viability, assessed by MTT quantitative colorimetric assay, intracellular reactive oxygen species (ROS) quantified by the non-fluorescent probe H2DCF-DA and changes in mitochondrial transmembrane potential (ΔΨm) measured by the incorporation of a cationic fluorescent dye rhodamine-123 were verified on venom-treated cells (0.05-0.5μg/ml doses). A dose- and time-dependent reduction of all parameters was observed after venom treatment. NAC (N-acetyl-cysteine), antioxidant applied before crude venom application, significantly counteracted the decrease in cell viability and ROS production, while ΔΨm was only partially restored. The disruption of mitochondrial membrane by P. noctiluca crude venom may thus induce oxidative stress by inhibiting mitochondrial respiration and uncoupling oxidative phosphorylation, sensitizing mitochondria in SH-SY5H cells and facilitating membrane permeability. In sum, our findings suggest that P. noctiluca crude venom directly induces ΔΨm collapse with further generation of ROS and add novel information to the understanding of such toxins, still not completely clarified.

  3. 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.

  4. 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

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

    SciTech Connect

    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 Ca2 +-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 1.30 Å 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 (473–474 nm with no shoulder at 400 nm). Fluorescence spectra of Ca2 +-discharged mitrocomins were almost identical to their light emission spectra similar to the case of Ca2 +-discharged aequorin, but different from Ca2 +-discharged obelins and clytin which fluorescence is red-shifted by 25–30 nm 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.

  6. 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.…

  7. 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)

  8. 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

  9. 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.

  10. Endobiotic bacteria and their pathogenic potential in cnidarian tentacles

    NASA Astrophysics Data System (ADS)

    Schuett, Christian; Doepke, Hilke

    2010-09-01

    Endobiotic bacteria colonize the tentacles of cnidaria. This paper provides first insight into the bacterial spectrum and its potential of pathogenic activities inside four cnidarian species. Sample material originating from Scottish waters comprises the jellyfish species Cyanea capillata and C. lamarckii, hydrozoa Tubularia indivisa and sea anemone Sagartia elegans. Mixed cultures of endobiotic bacteria, pure cultures selected on basis of haemolysis, but also lyophilized samples were prepared from tentacles and used for DGGE-profiling with subsequent phylogenetic analysis of 16S rDNA fragments. Bacteria were detected in each of the cnidarian species tested. Twenty-one bacterial species including four groups of closely related organisms were found in culture material. The species within these groups could not be differentiated from each other (one group of Pseudoalteromonas spp., two groups of Shewanella spp., one group of Vibrio spp.). Each of the hosts exhibits a specific endobacterial spectrum. Solely Cyanea lamarckii harboured Moritella viscosa. Only in Cyanea capillata, members of the Shewanella group #2 and the species Pseudoalteromonas arctica, Shewanella violacea, Sulfitobacter pontiacus and Arcobacter butzleri were detected. Hydrozoa Tubularia indivisa provided an amazingly wide spectrum of nine bacterial species. Exclusively, in the sea anemone Sagartia elegans, the bacterial species P. aliena was found. Overall eleven bacterial species detected were described recently as novel species. Four 16S rDNA fragments generated from lyophilized material displayed extremely low relationship to their next neighbours. These organisms are regarded as members of the endobiotic “terra incognita”. Since the origin of cnidarian toxins is unclear, the possible pathogenic activity of endobiotic bacteria has to be taken into account. Literature data show that their next neighbours display an interesting diversity of haemolytic, septicaemic and necrotic actions including

  11. Postembryonic development of the parasitic amphipod Hyperia galba

    NASA Astrophysics Data System (ADS)

    Dittrich, Birgit

    1987-06-01

    Hyperia galba Montagu is associated with gelatinous zooplankton as are many species of the Hyperiidea. The hosts preferred in the European seas are the large scyphomedusae Aurelia aurita, Chrysaora hysoscella, Rhizostoma pulmo, Cyanea capillata and Cyanea lamarckii, which harbour the first developmental stages. The anamorphic development produces young that are incapable of swimming at the time of hatching. They are characterized by an embryonic abdomen without extremities and external segmentation; the eyes are not completely developed and the mouth is primitive lacking bristles, molar and incisor. The postembryonic development, described in detail, is subdivided into two phases: the pantochelis phase and the protopleon phase; the former comprises only one stage; the latter can be subdivided into four stages. In the course of postnatal development the larval organs are reduced and characters typical of the adult are gradually differentiated. H. galba plays an important role as obligatory endoparasite of scyphomedusae at least during the first stages of development; without a host this amphipod cannot survive, neither benthically nor in the plankton. The transition from life in the female's marsupium to endoparasitism in the jellyfish generally occurs during stage of the postembryonic development which is the first stage of the protopleon phase. The specific adaptations of its reproductive biology to a parasitic mode of life such as moult inhibition under starvation, development of larval organs and the behavioural patterns of the females as well as the young are described. Further, the influence of external factors such as temperature and food supply on the course of development is examined.

  12. Muscle and nerve net organization in stalked jellyfish (Medusozoa: Staurozoa).

    PubMed

    Westlake, Hannah E; Page, Louise R

    2017-01-01

    Staurozoan cnidarians display an unusual combination of polyp and medusa characteristics and their morphology may be informative about the evolutionary origin of medusae. We studied neuromuscular morphology of two staurozoans, Haliclystus 'sanjuanensis' and Manania handi, using whole mount immunohistochemistry with antibodies against FMRFamide and α-tubulin to label neurons and phalloidin to label muscles. All muscles appeared to lack striations. Longitudinal interradial muscles are probable homologues of stalk muscles in scyphopolyps, but in adult staurozoans they are elaborated to inwardly flex marginal lobes of the calyx during prey capture; these muscles are pennate in M. handi. Manubrial perradial muscles, like the manubrium itself, are an innovation shared with pelagic medusae and manubrial interradial muscles are shared with scyphozoan ephyra. Marginal muscles of M. handi displayed occasional synchronous contraction reminiscent of a medusa swim pulse, but contractions were not repetitive. The nerve net in both species showed regional variation in density and orientation of neurons. Some areas labeled predominantly by α-tubulin antibodies (exumbrellar epidermis), other areas labeled exclusively by FMRFamide antibodies (dense plexus of neurites surrounding the base of secondary tentacles, neuronal concentration at the base of transformed primary tentacles; gastrodermal nerve net), but most areas showed a mix of neurons labeled by these two antibodies and frequent co-labeling of neurons. Transformed primary tentacles had a concentration of FMRFamide-immunoreactive neurons at their base that was associated with a pigment spot in M. handi; this is consistent with their homology with rhopalia of medusae, which are also derived from primary tentacles. The muscular system of these staurozoans embodies characteristics of both scyphopolyps and pelagic medusae. However, their nerve net is more polyp-like, although marginal concentrations of the net associated with primary and secondary tentacles may facilitate the richer behavioral repertoire of staurozoans relative to polyps of other medusozoans. J. Morphol. 278:29-49, 2017. ©© 2016 Wiley Periodicals,Inc.

  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. Nuclear organisation of some immunohistochemically identifiable neural systems in five species of insectivore-Crocidura cyanea, Crocidura olivieri, Sylvisorex ollula, Paraechinus aethiopicus and Atelerix frontalis.

    PubMed

    Calvey, Tanya; Patzke, Nina; Bennett, Nigel C; Consolate, Kaswera-Kyamakya; Gilissen, Emmanuel; Alagaili, Abdulaziz N; Mohammed, Osama B; Pettigrew, John D; Manger, Paul R

    2016-03-01

    The organization of the cholinergic, catecholaminergic, and serotonergic neurons in the brains of five species of insectivores and the orexinergic (hypocretinergic) system in four insectivore species is presented. We aimed to investigate the nuclear complement of these neural systems in comparison to those of other mammalian species. Brains of insectivores were coronally sectioned and immunohistochemically stained with antibodies against choline acetyltransferase, tyrosine hydroxylase, serotonin and orexin-A. The majority of nuclei were similar among the species investigated and to mammals in general, but certain differences in the nuclear complement highlighted potential phylogenetic interrelationships. In the cholinergic system, the three shrew species lacked parabigeminal and Edinger-Westphal nuclei. In addition, the appearance of the laterodorsal tegmental nucleus in all insectivores revealed a mediodorsal arch. All three of these features are the same as those present in microchiropterans. The catecholaminergic system of the three shrew species lacked the A4 and A15d nuclei, as well as having an incipient A9v nucleus, again features found in microchiropteran brains. The serotonergic and orexinergic systems of the insectivores are similar to those seen across most eutherian mammals. The analysis of similarities and differences across mammalian species indicates a potential phylogenetic relationship between the Soricidae (shrews) and the microchiropterans.

  15. The medusa stage of the coronate scyphomedusa Linuche unguiculata ('thimble jellyfish') can cause seabather's eruption.

    PubMed

    Segura Puertas, L; Burnett, J W; Heimer de la Cotera, E

    1999-01-01

    Adult Linuche unguiculata medusae cause seabather's eruption just like that animal's larval form. This observation explains the wide seasonal incidence and the fact that lesions can appear on exposed skin.

  16. 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.

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

    NASA Astrophysics Data System (ADS)

    Katija, K.; Dabiri, J. O.

    2007-12-01

    We conduct laboratory measurements of the flow fields induced by Aurelia labiata over a range of sizes using the method of digital particle image velocimetry (DPIV). The flow field measurements are used to directly quantify the kinetic energy induced by the swimming motions of individual medusae. This method provides details regarding the temporal evolution of the energetics during a swimming cycle and its scaling with bell diameter. These types of measurements also allow for the determination of propulsive efficiency, which can be used to compare various methods of propulsion, both biological and artificial. We then describe the development and application of a Self-Contained Underwater Velocimetry Apparatus (SCUVA), a device that enables a single SCUBA diver to make DPIV measurements of animal-fluid interactions in the field. Improvements and adjustments made to the original system will be presented, and a comparison between the animal-induced flow fields in the laboratory and in the field will be made.

  18. Lack of genetic structure in the jellyfish Pelagia noctiluca (Cnidaria: Scyphozoa: Semaeostomeae) across European seas.

    PubMed

    Stopar, Katja; Ramsak, Andreja; Trontelj, Peter; Malej, Alenka

    2010-10-01

    The genetic structure of the holopelagic scyphozoan Pelagia noctiluca was inferred based on the study of 144 adult medusae. The areas of study were five geographic regions in two European seas (Eastern Atlantic and Mediterranean Sea). A 655-bp sequence of mitochondrial cytochrome c oxidase subunit I (COI), and a 645-bp sequence of two nuclear internal transcribed spacers (ITS1 and ITS2) were analyzed. The protein coding COI gene showed a higher level of divergence than the combined nuclear ITS fragment (haplotype diversity 0.962 vs. 0.723, nucleotide diversity 1.16% vs. 0.31%). Phylogeographic analysis on COI gene revealed two clades, the larger consisting of specimens from all sampling sites, and the smaller mostly formed of specimens from the Mediterranean Sea. Haplotype diversity was very high throughout the sampled area, and within sample diversity was higher than diversity among geographical regions. No strongly supported genetically or geographically distinct groups of P. noctiluca were found. The results - long distance dispersal, insignificant F(ST) values, lack of isolation by distance - pointed toward an admixture among Mediterranean and East Atlantic populations.

  19. 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

  20. 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.

  1. 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

  2. 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.

  3. 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.

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

    PubMed

    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.

  5. 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.

  6. 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.

  7. 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

  8. VizieR Online Data Catalog: Jellyfish galaxy candidates in galaxy clusters (Poggianti+, 2016)

    NASA Astrophysics Data System (ADS)

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

    2016-10-01

    WIde-field Nearby Galaxy-cluster Survey (WINGS) is a large survey targeting 76 clusters of galaxies selected on the basis of their X-ray luminosity (Ebeling et al. 1996, Cat. J/MNRAS/281/799; Ebeling et al. 1998, Cat. J/MNRAS/301/881; Ebeling et al. 2000, Cat. J/MNRAS/318/333), covering a wide range in cluster masses (σ=500-1200+km/s, logLX=43.3-45erg/s, Fasano et al. 2006A&A...445..805F). The original WINGS data set consisted of B and V deep photometry of a 34'*34' field of view with the WFC@INT and the WFC@2.2mMPG/ESO (Varela et al. 2009, Cat. J/A+A/497/667), spectroscopic follow-ups with 2dF@AAT and WYFFOS@WHT (Cava et al. 2009, Cat. J/A+A/495/707), plus J and K imaging with WFC@UKIRT (Valentinuzzi et al. 2009, Cat. J/A+A/501/851) and some U-band imaging (Omizzolo et al. 2014, Cat. J/A+A/561/A111). This database is presented in Moretti et al. 2014A&A...564A.138M and has been employed for a number of studies (see https://sites.google.com/site/wingsomegawings/). OmegaCAM-VST observations of WINGS galaxy clusters (OMEGAWINGS) is a recent extention of this project, that quadruples the area covered (1deg2) and allows to reach up to ~2.5 cluster virial radii. OMEGAWINGS is based on two OmegaCAM@VST GTO programs for 46 WINGS clusters: a B and V campaign completed in P93, and an ongoing u-band programme. The B and V data, the data reduction and the photometric catalogs are presented in Gullieuszik et al. 2015 (Cat. J/A+A/581/A41). Spectra are obtained with AAOmega@AAT on the OmegaCAM field. So far, we have secured high quality spectra for ~30 OMEGAWINGS clusters, reaching very high spectroscopic completeness levels for galaxies brighter than V=20 from the cluster cores to their periphery (A. Moretti et al. 2016, in preparation). Galaxies are considered cluster members if they are within 3σ from the cluster redshift. The mean redshift uncertainty, computed from the differences between WINGS and OMEGAWINGS redshift values of repeated objects, is Δz=0.0002. For this paper we consider the 41 OMEGAWINGS clusters with an OmegaCAM B and/or V-band seeing {<=}1.2arcsec, listed in Table1. To complete the search within the WINGS sample, we used the old WINGS images for other 31 clusters not observed with OmegaCAM (Table1). The reference comparison field sample for WINGS and OMEGAWINGS is the Padova Millennium Galaxy and Group Catalog (PM2GC; Calvi et al. 2011, Cat. J/MNRAS/416/727), built from the Millennium Galaxy Catalogue (MGC; Liske et al. 2003, Cat. VII/240), a deep 38deg2 INT B-imaging survey with a highly complete spectroscopic follow-up (96% at B=20, Driver et al. 2005, Cat. VII/240). (3 data files).

  9. 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.

  10. Stable isotopes challenge the perception of ocean sunfish Mola mola as obligate jellyfish predators.

    PubMed

    Syväranta, J; Harrod, C; Kubicek, L; Cappanera, V; Houghton, J D R

    2012-01-01

    Evidence is provided from stable isotope analysis that aggregations of small ocean sunfish Mola mola (total length <1 m) feed broadly within coastal food webs and their classification as obligate predators of gelatinous zooplankton requires revision.

  11. 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

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. Pharmacological actions of tentacle extract of the jellyfish, Acromitus rabanchatu, occurring in the Bay of Bengal.

    PubMed

    Ghosh, T K; Gomes, A; Chaudhuri, A K

    1990-01-01

    Tentacle extract of A.rabanchatu, produced a fall of blood pressure in cat, rat and guinea pig. Hypotension produced in cat remained unantagonized by blockers of acetylcholine, histamine and 5-HT. On isolated guinea pig heart, the extract significantly reduced the rate and amplitude of contraction leading to irreversible cardiac arrest. In cats and rats, the respiratory rate and amplitude was decreased significantly and resulted in temporary apnoea. The extract also produced vasoconstriction in perfused rat hindquarter preparation and increased cutaneous capillary permeability. The extract produced contraction in several isolated smooth muscle preparations. Contraction on guinea pig ileum was partly antagonized by atropine and cyproheptadine. On isolated rat phrenic nerve diaphragm and chick biventer cervicis, the extract produced irreversible blockade of the electrical stimulation-induced twitch responses. Haemolytic and myonecrotic activity was exhibited by the extract. LD50 was found to be 7.7 mg/kg (iv, mice).

  17. Information Visualization: The State of the Art for Maritime Domain Awareness

    DTIC Science & Technology

    2006-08-01

    96 3.3.11.10 Jellyfish .......................................................................... 96...Aperture software is focused on IT infrastructure management and visualization. 3.3.11.10 Jellyfish Ref: http://www.carohorn.de/ jellyfish /index.htm 96

  18. Semantic Assembly and Annotation of Draft RNAseq Transcripts without a Reference Genome

    PubMed Central

    Ptitsyn, Andrey; Temanni, Ramzi; Bouchard, Christelle; Anderson, Peter A. V.

    2015-01-01

    Transcriptomes are one of the first sources of high-throughput genomic data that have benefitted from the introduction of Next-Gen Sequencing. As sequencing technology becomes more accessible, transcriptome sequencing is applicable to multiple organisms for which genome sequences are unavailable. Currently all methods for de novo assembly are based on the concept of matching the nucleotide context overlapping between short fragments-reads. However, even short reads may still contain biologically relevant information which can be used as hints in guiding the assembly process. We propose a computational workflow for the reconstruction and functional annotation of expressed gene transcripts that does not require a reference genome sequence and can be tolerant to low coverage, high error rates and other issues that often lead to poor results of de novo assembly in studies of non-model organisms. We start with either raw sequences or the output of a context-based de novo transcriptome assembly. Instead of mapping reads to a reference genome or creating a completely unsupervised clustering of reads, we assemble the unknown transcriptome using nearest homologs from a public database as seeds. We consider even distant relations, indirectly linking protein-coding fragments to entire gene families in multiple distantly related genomes. The intended application of the proposed method is an additional step of semantic (based on relations between protein-coding fragments) scaffolding following traditional (i.e. based on sequence overlap) de novo assembly. The method we developed was effective in analysis of the jellyfish Cyanea capillata transcriptome and may be applicable in other studies of gene expression in species lacking a high quality reference genome sequence. Our algorithms are implemented in C and designed for parallel computation using a high-performance computer. The software is available free of charge via an open source license. PMID:26393794

  19. Semantic Assembly and Annotation of Draft RNAseq Transcripts without a Reference Genome.

    PubMed

    Ptitsyn, Andrey; Temanni, Ramzi; Bouchard, Christelle; Anderson, Peter A V

    2015-01-01

    Transcriptomes are one of the first sources of high-throughput genomic data that have benefitted from the introduction of Next-Gen Sequencing. As sequencing technology becomes more accessible, transcriptome sequencing is applicable to multiple organisms for which genome sequences are unavailable. Currently all methods for de novo assembly are based on the concept of matching the nucleotide context overlapping between short fragments-reads. However, even short reads may still contain biologically relevant information which can be used as hints in guiding the assembly process. We propose a computational workflow for the reconstruction and functional annotation of expressed gene transcripts that does not require a reference genome sequence and can be tolerant to low coverage, high error rates and other issues that often lead to poor results of de novo assembly in studies of non-model organisms. We start with either raw sequences or the output of a context-based de novo transcriptome assembly. Instead of mapping reads to a reference genome or creating a completely unsupervised clustering of reads, we assemble the unknown transcriptome using nearest homologs from a public database as seeds. We consider even distant relations, indirectly linking protein-coding fragments to entire gene families in multiple distantly related genomes. The intended application of the proposed method is an additional step of semantic (based on relations between protein-coding fragments) scaffolding following traditional (i.e. based on sequence overlap) de novo assembly. The method we developed was effective in analysis of the jellyfish Cyanea capillata transcriptome and may be applicable in other studies of gene expression in species lacking a high quality reference genome sequence. Our algorithms are implemented in C and designed for parallel computation using a high-performance computer. The software is available free of charge via an open source license.

  20. 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…

  1. 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.

  2. Complete mitochondrial genome and evolutionary analysis of Turritopsis dohrnii, the "immortal" jellyfish with a reversible life-cycle.

    PubMed

    Lisenkova, A A; Grigorenko, A P; Tyazhelova, T V; Andreeva, T V; Gusev, F E; Manakhov, A D; Goltsov, A Yu; Piraino, S; Miglietta, M P; Rogaev, E I

    2017-02-01

    Turritopsis dohrnii (Cnidaria, Hydrozoa, Hydroidolina, Anthoathecata) is the only known metazoan that is capable of reversing its life cycle via morph rejuvenation from the adult medusa stage to the juvenile polyp stage. Here, we present a complete mitochondrial (mt) genome sequence of T. dohrnii, which harbors genes for 13 proteins, two transfer RNAs, and two ribosomal RNAs. The T. dohrnii mt genome is characterized by typical features of species in the Hydroidolina subclass, such as a high A+T content (71.5%), reversed transcriptional orientation for the large rRNA subunit gene, and paucity of CGN codons. An incomplete complementary duplicate of the cox1 gene was found at the 5' end of the T. dohrnii mt chromosome, as were variable repeat regions flanking the chromosome. We identified species-specific variations (nad5, nad6, cob, and cox1 genes) and putative selective constraints (atp8, nad1, nad2, and nad5 genes) in the mt genes of T. dohrnii, and predicted alterations in tertiary structures of respiratory chain proteins (NADH4, NADH5, and COX1 proteins) of T. dohrnii. Based on comparative analyses of available hydrozoan mt genomes, we also determined the taxonomic relationships of T. dohrnii, recovering Filifera IV as a paraphyletic taxon, and assessed intraspecific diversity of various Hydrozoa species.

  3. 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.

  4. Bringing the Jellyfish Home: Environmental Consciousness and "Sense of Wonder" in Young Children's Encounters with Natural Landscapes and Places

    ERIC Educational Resources Information Center

    Jørgensen, Kari-Anne

    2016-01-01

    The over-arching aim of this study was to elucidate and interpret topics that are relevant to how we understand children's experiences and creation of meaning in natural landscapes and places within these landscapes. Following two nature-kindergarten groups regularly over ten months, the data for this ethnographic study consist of constructed…

  5. 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.

  6. 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.

  7. Molten Boron Phase-Change Thermal Energy Storage to Augment Solar Thermal Propulsion Systems

    DTIC Science & Technology

    2011-07-22

    these formations " jellyfish " due to the observed motion. There were also much shorter-lived clouds arranged in a more spherical group that often (but...not exclusively) burst into appearance near the jellyfish formations, would quickly dart in any direction, and then disappear. Typically, the... jellyfish formations might expand and contract from 0.5-2 mm in diameter up to 3-5 mm diameter. At higher power levels, the apparent jellyfish formations

  8. Monitoring Bloom Dynamics of a Common Coastal Bioluminescent Ctenophore

    DTIC Science & Technology

    2009-09-30

    potential in the coastal zone environment. OBJECTIVES Blooms of bioluminescent jellyfish , especially of Mnemiopsis leidyi, are a common occurrence... jellyfish populations are done with net collections by hand at stations weekly, monthly, or seasonally. These time scales severely limit our knowledge...the collection of both biotic and abiotic data continuously. 5 IMPACT/APPLICATIONS As incidents of jellyfish blooms, especially Mnemiopsis

  9. Studies of FAUNA at Eglin Air Force Base

    DTIC Science & Technology

    2006-07-01

    virginianus GHOW Hairy woodpecker* Picoides villosus HAWO Indigo bunting Passerina cyanea INBU Loggerhead shrike Lanius ludovicianus LOSH...Migrants American goldfinch Carduelis tristis AMGO Cedar waxwing Bombycilla cedrorum CEDW Chipping sparrow Spizella passerina CHSP 43

  10. Final Environmental Assessment for the Military Family Housing Privatization Initiative Columbus Air Force Base, Mississippi

    DTIC Science & Technology

    2005-05-03

    Loggerhead shrike Ducks Aix sponsa Wood duck New World cuckoos Coccyzus americanus Yellow-billed cuckoo Colaptes auratus Northern flicker Enturus...Passerina cyanea Indigo bunting Melospiza melodia Song sparrow Passerculus sandwichensis Savanna sparrow Pipilo erythrophthalmus Rufus-sided towhee

  11. A revision of the myrmecophilous genus Smilax Laporte (Coleoptera: Staphylinidae: Staphylininae).

    PubMed

    Chatzimanolis, Stylianos

    2016-09-09

    The neotropical myrmecophilous genus Smilax is revised and a new species, Smilax deneinephyto Chatzimanolis is described from southern Brazil. Lectotypes are designated for Smilax cyanea Wasmann and Staphylinus pilosus Fabricius. Smilax cyanea is shown to be a junior synonym of Smilax pilosa. A key and illustration of morphological features are provided for the identification of taxa. The types of the two species of Smilax were not available for study even though they are deposited in public museums.

  12. A new species of Pseudomacrochiron Reddiah, 1969 (Crustacea: Copepoda: Macrochironidae) associated with scyphistomae of the moon jellyfish Aurelia sp. (Cnidaria: Scyphozoa) off Japan.

    PubMed

    Tang, Danny; Yasuda, Akira; Yamada, Satoshi; Nagasawa, Kazuya

    2012-02-01

    A new species of the Macrochironidae Humes & Boxshall, 1996 (Copepoda: Cyclopoida), Pseudomacrochiron aureliae n. sp., is described based on adult specimens extracted from the gastrovacular cavity of the scyphistomae of Aurelia sp. (Cnidaria: Scyphozoa) collected in the Seto Inland Sea and Ise Bay off the coast of Japan. The new species differs from its congeners by having the following combination of characters: a caudal ramus with a length to width ratio of 3.1; an accessory flagellum on caudal setae II, III and VI; three apical setae on the maxillule; only setae I and II on the maxillary basis; two short spines on the female maxilliped claw (endopod); an armature of III, I, 4 on the terminal exopodal segment of leg 3; an armature of I, II, 2 on the terminal endopodal segment of leg 3; an armature of II, I, 4 on the terminal exopodal segment of leg 4; and a short free exopodal segment of leg 5 (length to width ratio of 1.4) armed with a long seta and short spine. P. aureliae n. sp. is the first member of the genus reported from off Japan and from the scyphistomae of its scyphozoan host.

  13. A Survey of Satellite Communications System Vulnerabilities

    DTIC Science & Technology

    2008-06-01

    overflows, rushing attacks, neighbor attacks, black hole attacks, and jellyfish attacks [100, 105, 117]. Flooding attacks involve the attacker sending...packets, this is termed a black hole attack. This type of attack degrades network performance by reducing packet delivery. A jellyfish attack...them. Jellyfish attacks diminish the ability to provide real-time communications by increasing the end- to-end communications delay [117]. 4.4.3

  14. Cnidocytes as Microscale Synthesis and Delivery Modules

    DTIC Science & Technology

    2008-05-31

    findings for nematocysts isolated from other species. Note that Physalia is not a true jellyfish , suggesting that the mechanisms behind discharge are not...also developed methods for culturing cells from jellyfish . The work began using Physalia, but has also used the sea nettle, Chrysaora, and the hydroid...also plated onto fragments of mesoglea, the “jelly” of the jellyfish , prepared in a variety of ways. This substrate has been used successfully by

  15. Joint Improvised Explosive Device Defeat Organization: Anomaly or Future Roadmap

    DTIC Science & Technology

    2008-03-25

    fleet.45 He further relates that the submarine problem was analogous to “lifting an immense jellyfish .” No single answer could produce the complete...like that of lifting an immense jellyfish . Grasping it with two hands accomplishing nothing, but with hands-all-around and heaving together, one...can we lift the “immense jellyfish ” and hope to be successful. 20 Endnotes 1Rick Atkinson, “Left of Boom: The Struggle to Defeat Roadside Bombs

  16. Synthetic Biomimetic Fluorophores for Micro/Nanosensor

    DTIC Science & Technology

    2006-11-01

    as a companion protein to aequorin, the famous chemiluminescent protein from the brightly luminescent Aequorea jellyfish , with glowing points...peaked near 470 nm, which was close to one of the excitation peaks of GFP. Aequorin, isolated from the jellyfish Aequorea victoria, is a complex of...partially homologous to green fluorescent protein (GFP) (Matz et al. 1999, Dove et al. 2000), first found in the luminescent jellyfish Aequorea and used

  17. West Europe Report No. 2230

    DTIC Science & Technology

    2007-11-02

    jellyfish , occasionally even representing a danger to human life, along the coast are mainly the result of oil tankers rinsing out their tanks on the...high seas, for fauna feeding on jellyfish is now either extinct or, like the Caretta turtle, stays away from polluted areas. 81 Yet, when tourists

  18. AFGHAN Civilian Police: Police Instead of Soldiers

    DTIC Science & Technology

    2010-03-01

    differs from Islamic Law “Sharia” enforced by mullahs. See Tribal Analysis Center, “Starfish, Spiders and Jellyfish : Pashtun Cultural Factors...Spiders and Jellyfish : Pashtun Cultural Factors limiting Warlord Development,” 2009. http://www.tribalanalysiscenter.com/freePDF/Afghanistan%20A

  19. 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.

  20. 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

  1. 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.

  2. Marine ecology: gelatinous bells may ring change in marine ecosystems.

    PubMed

    Hay, Steve

    2006-09-05

    Gelatinous plankton are critical components of marine ecosystems. Recent studies are providing evidence of increased population outbursts of such species. Jellyfish seem to respond when an ecosystem is over-fished, and their ecology is under-researched.

  3. Toxicity of Mediterranean Scyphomedusae: An Overview.

    PubMed

    Negro, Paola Del; Saul, Ciriaco; Bruno, Cataletto; Maria, Delogu G; Franco, Kokelj

    2016-01-01

    Following in-depth analysis and examination, jellyfish toxins have been found to consist of a mixture of proteins, carbohydrates, and other non-proteinaceous components. What remains to be clarified is the specific chemical nature of jellyfish toxins due to their heat lability. This paper reviews current knowledge of the toxic properties of the most common Mediterranean scyphozoans (A. aurita, C. hysoscella, C. tuberculata, P. noctiluca, R. pulmo) and the activity of their venom.

  4. The Role of Protein Kinase-C in Breast Cancer Invasion and Metastasis

    DTIC Science & Technology

    1997-09-01

    the jellyfish Aequorea victoria . A modified form of this protein has been generated that has altered excitation and emission spectra so that it...relatively new reporter molecule that is being increasingly used in a variety of studies is the green fluorescent protein (GFP) from the jellyfish Aequorea ... victoria . A modified form of this protein has been generated that has altered excitation and emission spectra so that it works well with detection

  5. Integrating phylogenetic and population genetic analyses of multiple loci to test species divergence hypotheses in Passerina buntings.

    PubMed

    Carling, Matt D; Brumfield, Robb T

    2008-01-01

    Phylogenetic and population genetic analyses of DNA sequence data from 10 nuclear loci were used to test species divergence hypotheses within Passerina buntings, with special focus on a strongly supported, but controversial, sister relationship between Passerina amoena and P. caerulea inferred from a previous mitochondrial study. Here, a maximum-likelihood analysis of a concatenated 10-locus data set, as well as minimize-deep-coalescences and maximum-likelihood analyses of the locus-specific gene trees, recovered the traditional sister relationship between P. amoena and P. cyanea. In addition, a more recent divergence time estimate between P. amoena and P. cyanea than between P. amoena and P. caerulea provided evidence for the traditional sister relationship. These results provide a compelling example of how lineage sorting stochasticity can lead to incongruence between gene trees and species trees, and illustrate how phylogenetic and population genetic analyses can be integrated to investigate evolutionary relationships between recently diverged taxa.

  6. Adaptive radiation of photosynthetic physiology in the Hawaiian lobeliads: dynamic photosynthetic responses.

    PubMed

    Montgomery, Rebecca A; Givnish, Thomas J

    2008-03-01

    Hawaiian lobeliads have radiated into habitats from open alpine bogs to densely shaded rainforest interiors, and show corresponding adaptations in steady-state photosynthetic light responses and associated leaf traits. Shaded environments are not uniformly dark, however, but punctuated by sunflecks that carry most of the photosynthetically active light that strikes plants. We asked whether lobeliads have diversified in their dynamic photosynthetic light responses and how dynamic responses influence daily leaf carbon gain. We quantified gas exchange and dynamic light regimes under field conditions for ten species representing each major Hawaiian sublineage. Species in shadier habitats experienced shorter and less numerous sunflecks: average sunfleck length varied from 1.4 +/- 1.7 min for Cyanea floribunda in shaded forest understories to 31.2 +/- 2.1 min for Trematolobelia kauaiensis on open ridges. As expected, the rate of photosynthetic induction increased significantly toward shadier sites, with assimilation after 60 s rising from ca. 30% of fully induced rates in species from open environments to 60% in those from densely shaded habitats. Uninduced light use efficiency-actual photosynthesis versus that expected under steady-state conditions-increased from 10 to 70% across the same gradient. In silico transplants-modeling daily carbon gain using one species' photosynthetic light response in its own and other species' dynamic light regimes-demonstrated the potential adaptive nature of species differences: understory Cyanea pilosa in its light regimes outperformed gap-dwelling Clermontia parviflora, while Clermontia in its light regimes outperformed Cyanea. The apparent crossover in daily photosynthesis occurred at about the same photon flux density where dominance shifts from Cyanea to Clermontia in the field. Our results further support our hypothesis that the lobeliads have diversified physiologically across light environments in Hawaiian ecosystems and that

  7. Speciation in Passerina buntings: introgression patterns of sex-linked loci identify a candidate gene region for reproductive isolation.

    PubMed

    Carling, Matthew D; Brumfield, Robb T

    2009-03-01

    Sex-chromosomes are thought to play an important role in speciation, but few studies of non-model organisms have investigated the relative influence of multiple sex-linked markers on reproductive isolation. We collected 222 individuals along a geographical transect spanning the hybrid zone between Passerina amoena and P. cyanea (Aves: Cardinalidae). Using maximum-likelihood cline fitting methods, we estimated locus-specific introgression rates for 10 z-linked markers. Although the cline width estimates ranged from 2.8 to 584 km, eight of 10 loci had cline widths between 224 and 271 km. We also used coalescent-based estimates of locus-specific divergence times between P. amoena and P. cyanea to test a recently proposed hypothesis of an inverse relationship between divergence time and cline width but did not find a significant association. The narrow width (2.8 km) of the cline estimated from the VLDLR9 locus indicates strong selection retarding introgression of alleles at this locus across the hybrid zone. Interestingly, a mutation in the very low density lipoprotein receptor (VLDLR) gene, in which VLDLR9 is an intron, is known to reduce the egg-laying ability of some chickens, suggesting a possible link between this gene region and reproductive isolation between P. amoena and P. cyanea. These results underscore the importance of sampling multiple loci to investigate introgression patterns across a chromosome or genome and support previous findings of the importance of sex-linked genes in speciation.

  8. Origin, adaptive radiation and diversification of the Hawaiian lobeliads (Asterales: Campanulaceae).

    PubMed

    Givnish, Thomas J; Millam, Kendra C; Mast, Austin R; Paterson, Thomas B; Theim, Terra J; Hipp, Andrew L; Henss, Jillian M; Smith, James F; Wood, Kenneth R; Sytsma, Kenneth J

    2009-02-07

    The endemic Hawaiian lobeliads are exceptionally species rich and exhibit striking diversity in habitat, growth form, pollination biology and seed dispersal, but their origins and pattern of diversification remain shrouded in mystery. Up to five independent colonizations have been proposed based on morphological differences among extant taxa. We present a molecular phylogeny showing that the Hawaiian lobeliads are the product of one immigration event; that they are the largest plant clade on any single oceanic island or archipelago; that their ancestor arrived roughly 13 Myr ago; and that this ancestor was most likely woody, wind-dispersed, bird-pollinated, and adapted to open habitats at mid-elevations. Invasion of closed tropical forests is associated with evolution of fleshy fruits. Limited dispersal of such fruits in wet-forest understoreys appears to have accelerated speciation and led to a series of parallel adaptive radiations in Cyanea, with most species restricted to single islands. Consistency of Cyanea diversity across all tall islands except Hawai ;i suggests that diversification of Cyanea saturates in less than 1.5 Myr. Lobeliad diversity appears to reflect a hierarchical adaptive radiation in habitat, then elevation and flower-tube length, and provides important insights into the pattern and tempo of diversification in a species-rich clade of tropical plants.

  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. The Mauve Stinger Pelagia noctiluca (Forsskål, 1775). Distribution, Ecology, Toxicity and Epidemiology of Stings. A Review

    PubMed Central

    Mariottini, Gian Luigi; Giacco, Elisabetta; Pane, Luigi

    2008-01-01

    The toxicity of Cnidaria is a subject of concern due to its influence on humans. In particular, jellyfish blooms can highly affect human economical activities, such as bathing, fishery, tourism, etc., as well as the public health. Stinging structures of Cnidaria (nematocysts) produce remarkable effects on human skin, such as erythema, swelling, burning and vesicles, and at times further severe dermonecrotic, cardio- and neurotoxic effects, which are particularly dangerous in sensitive subjects. In several zones the toxicity of jellyfish is a very important health problem, thus it has stimulated the research on these organisms; to date toxicological research on Cnidarian venoms in the Mediterranean region is not well developed due to the weak poisonousness of venoms of jellyfish and anemones living in this area. In spite of this, during last decades several problems were also caused in the Mediterranean by stinging consequent to Cnidarian blooms mainly caused by Pelagia noctiluca (Forsskål, 1775) which is known to be the most venomous Mediterranean jellyfish. This paper reviews the knowledge on this jellyfish species, particularly considering its occurrence and toxicity. PMID:19005582

  11. 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.

  12. Marine envenomations.

    PubMed

    Balhara, Kamna S; Stolbach, Andrew

    2014-02-01

    This article describes the epidemiology and presentation of human envenomation from marine organisms. Venom pathophysiology, envenomation presentation, and treatment options are discussed for sea snake, stingray, spiny fish, jellyfish, octopus, cone snail, sea urchin, and sponge envenomation. The authors describe the management of common exposures that cause morbidity as well as the keys to recognition and treatment of life-threatening exposures.

  13. 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;…

  14. In situ detrimental impacts of Prorocentrum donghaiense blooms on zooplankton in the East China Sea.

    PubMed

    Lin, Jia-Ning; Yan, Tian; Zhang, Qing-Chun; Wang, Yun-Feng; Liu, Qing; Zhou, Ming-Jiang

    2014-11-15

    Large-scale algal blooms of the dinoflagellate Prorocentrum donghaiense have occurred frequently in the East China Sea (ECS) in recent decades. However, its impacts on the zooplankton in situ are still under not well understood. During a spring P. donghaiense bloom (April-May 2013) along the northern coast of Fujian Province (120°-121°30″E, 26°30″-28°N), we found that the bloom decreased the abundance of copepods and had no significant effect on chaetognaths and small jellyfish. However, the abundance of small jellyfish increased over the course of the study. The zooplankton community changed from being copepod and small jellyfish- to small jellyfish-dominated during the bloom. In the bloom areas, the copepod Calanus sinicus showed higher mortality and lower egg production rates (EPR) than those in the non-bloom areas. The results suggested that P. donghaiense blooms had detrimental effects on the structure of zooplankton community and the recruitments of C. sinicus.

  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. Correlative Light and Electron Microscopy (CLEM) and its applications in infectious disease

    DTIC Science & Technology

    2016-05-20

    chromophore. Fluorescent proteins commonly used include green fluorescence protein (GFP) from jellyfish[45], red fluorescence protein (RFP) from corals...46, 47], and the coral-derived green -to-red photoconvertible fluorescent protein EosFP[48] . Additionally through mutagenesis and protein...engineering FP variants featuring fluorescence emission spanning much wider regions of the visible spectrum have been developed including blue, cyan, green

  17. 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…

  18. 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…

  19. Invasive Marine and Estuarine Animals of Hawaii and Other Pacific Islands

    DTIC Science & Technology

    2005-08-01

    V E RI CN NY NJ jPA DE ]MD [VA Re n Protozoans 2 2 2 2 3 Sponges 1 2 1 1 1 2 Jellyfish 2 3 4 Anemones 1 2 1 2 3 Hydrozoans 2 1 2 Platyhelminths 1 1...Anemone ME MA VA Sagartia elegans Anemone MA Cordylophora caspia Hydrozoa ME Convoluta convoluta Platyhelminth ME Tubificoides heterochaetus

  20. 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...

  1. 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,…

  2. 36 CFR 7.27 - Dry Tortugas National Park.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...) Caribbean spiny lobster (Panulirus argus); or (iv) Spotted spiny lobster (Panulirus guttatus). (10) Marine life means: (i) Sponges, sea anenomes, corals, jellyfish, sea cucumbers, starfish, sea urchins, octopus... formations, sea grass, or submerged cultural resources. (j) What restrictions apply on or near shipwrecks?...

  3. 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)

  4. 36 CFR 7.27 - Dry Tortugas National Park.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... life means: (i) Sponges, sea anenomes, corals, jellyfish, sea cucumbers, starfish, sea urchins, octopus... points of 82°51′ W and 24°36′ N, and 82°58′ W and 24°36′ N west to the park boundary, but excluding: (i... gasoline refueling dock. (4) The following are prohibited: (i) Possessing lobster within the boundaries...

  5. 36 CFR 7.27 - Dry Tortugas National Park.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... life means: (i) Sponges, sea anenomes, corals, jellyfish, sea cucumbers, starfish, sea urchins, octopus... points of 82°51′ W and 24°36′ N, and 82°58′ W and 24°36′ N west to the park boundary, but excluding: (i... gasoline refueling dock. (4) The following are prohibited: (i) Possessing lobster within the boundaries...

  6. 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.…

  7. 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.

  8. 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…

  9. 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,…

  10. Polychlorinated biphenyls may alter marine trophic pathways by reducing phytoplankton size and production.

    PubMed

    O'Connors, H B; Wurster, C F; Powers, C D; Biggs, D C; Rowland, R G

    1978-08-25

    Polychlorinated biphenyls at concentrations of 1 to 10 micrograms per liter reduced phytoplankton biomass and size in natural estuarine phytoplankton communities grown within dialysis bags in situ in an estuarine marsh. In polychlorinated biphenyls-contaminated waters, these changes could increase the number of trophic levels and divert the flow of biomass from harvestable fish to jellyfish and other gelatinous predators.

  11. Biological Activity at Oceanic Fronts.

    DTIC Science & Technology

    1985-12-01

    al. (1974) in a tidal (shallow sea) front in the English Channel. Most interestingly, a small *-. S jellyfish caught in the downwelling zone sank 28 m...and R.P. Harris. 1984. Photosynthesis, respiration and nitrogen supply of plankton populations in stratified, frontal, and tidally mixed she’-; waters

  12. Aspects of Thermal Pollution.

    DTIC Science & Technology

    1970-03-31

    the water and therefore accelerate the depletion of available oxygen necessary for animal respiration . Also in some instances, these conditions are...increased fouling of boats, buoys and other objects. The warmer outflows have been shown to cause exploding populations of jellyfish which make an area

  13. 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

  14. Induction of metamorphosis from the larval to the polyp stage is similar in Hydrozoa and a subgroup of Scyphozoa (Cnidaria, Semaeostomeae)

    NASA Astrophysics Data System (ADS)

    Siefker, Barbara; Kroiher, Michael; Berking, Stefan

    2000-12-01

    Larvae of cnidarians need an external cue for metamorphosis to start. The larvae of various hydrozoa, in particular of Hydractinia echinata, respond to Cs+, Li+, NH4 + and seawater in which the concentration of Mg2+ ions is reduced. They further respond to the phorbolester, tetradecanoyl-phorbol-13-acetate (TPA) and the diacylglycerol (DAG) diC8, which both are argued to stimulate a protein kinase C. The only well-studied scyphozoa, Cassiopea spp., respond differently, i.e. to TPA and diC8 only. We found that larvae of the scyphozoa Aurelia aurita, Chrysaora hysoscella and Cyanea lamarckii respond to all the compounds mentioned. Trigonelline ( N-methylnicotinic acid), a metamorphosis inhibitor found in Hydractinia larvae, is assumed to act by delivering a methyl group for transmethylation processes antagonising metamorphosis induction in Chrysaora hysoscella and Cyanea lamarckii. The three species tested are scyphozoa belonging to the subgroup of semaeostomeae, while Cassiopea spp. belong to the rhizostomeae. The results obtained may contribute to the discussion concerning the evolution of cnidarians and may help to clarify whether the way metamorphosis can be induced in rhizostomeae as a whole is different from that in hydrozoa and those scyphozoa belonging to the subgroup semaeostomeae.

  15. Kaolin and copper-based products applications: ecotoxicology on four natural enemies.

    PubMed

    Bengochea, P; Amor, F; Saelices, R; Hernando, S; Budia, F; Adán, A; Medina, P

    2013-05-01

    Lethal and sublethal effects of kaolin clays and two copper-based products on four natural enemies found in olive orchards Anthocoris nemoralis (F.) (Hem. Anthocoridae), Chelonus inanitus (L.) (Hym. Braconidae), Chilocorus nigritus (F.) (Col. Coccinellidae) and Scutellysta cyanea Motschulsky (Hym. Pteromalidae) are described. Both kaolin and copper can be applied for controlling the olive fruit fly and the olive moth, two important pests of this crop. The products did not increase the mortality of any of the insects studied, with the exception of A. nemoralis. The sublethal effects, however, differed depending on the parameter evaluated and the insect studied. Both kaolin and coppers slightly, but significantly, reduced the life span of C. inanitus and S. cyanea. Number of eggs laid by A. nemoralis females were reduced, but not significantly compared to the controls. In the behavioural experiments, clear preference for remaining on kaolin-untreated surfaces when insects were able to choose was observed. Despite having some negative effects, the negative impact on natural enemies was lower than the impact caused by products commonly applied in this crop against the pests stated above. Therefore, both kaolin and copper can be considered as alternative products to be applied in olive orchards if an effective resistance management programme is to be developed. Furthermore, both of them are allowed in organic farming, in which the number of products that can be applied is more restricted.

  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. 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.

  18. [Research advances in the effects of environmental factors on the growth and development of Aurelia spp].

    PubMed

    Wang, Jian-Yan; Yu, Zhi-Gang; Zhen, Yu; Mi, Tie-Zhu; Yao, Qing-Zhen; Wang, Guo-Shan

    2012-11-01

    Aurelia spp. is a cosmopolitan coastal species, and also, one dominant species of large jellyfish in the coastal waters of China. In recent years, Aurelia spp. bloom events occur frequently in the world, causing severe damage to marine ecosystems, coastal economy, and society development. Aurelia spp. has a complicated life history comprising a benthic asexually-reproducing polyp generation and a sexually-reproducing medusa generation, and various vegetative reproduction (budding, strobilation, and podocyst production) and sexual reproduction. Surrounding physical and biological factors affect each growth stage of Aurelia spp., especially the juvenile stage of planktonic-benthic life cycle, which has major effect on the population dynamics of Aurelia spp. This paper reviewed the research advances in the effects of environmental factors on Aurelia spp. at its different growth and development stages, and discussed some problems worthy of further study, aimed to provide useful reference for the research of the key factors controlling the jellyfish blooms in coastal waters of China.

  19. 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

    2015-06-25

    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.

  20. 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.

  1. Development of soft robots using dielectric elastomer actuators

    NASA Astrophysics Data System (ADS)

    Godaba, Hareesh; Wang, Yuzhe; Cao, Jiawei; Zhu, Jian

    2016-04-01

    Soft robots are gaining in popularity due to their unique attributes such as low weight, compliance, flexibility and diverse range in motion types. This paper illustrates soft robots and actuators which are developed using dielectric elastomer. These developments include a jellyfish robot, a worm like robot and artificial muscle actuators for jaw movement in a robotic skull. The jellyfish robot which employs a bulged dielectric elastomer membrane has been demonstrated too generate thrust and buoyant forces and can move effectively in water. The artificial muscle for jaw movement employs a pure shear configuration and has been shown to closely mimic the jaw motion while chewing or singing a song. Thee inchworm robot, powered by dielectric elastomer actuator can demonstrate stable movement in one-direction.

  2. 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.

  3. 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.

  4. Presynaptic spike broadening reduces junctional potential amplitude.

    PubMed

    Spencer, A N; Przysiezniak, J; Acosta-Urquidi, J; Basarsky, T A

    1989-08-24

    Presynaptic modulation of action potential duration may regulate synaptic transmission in both vertebrates and invertebrates. Such synaptic plasticity is brought about by modifications to membrane currents at presynaptic release sites, which, in turn, lead to changes in the concentration of cytosolic calcium available for mediating transmitter release. The 'primitive' neuromuscular junction of the jellyfish Polyorchis penicillatus is a useful model of presynaptic modulation. In this study, we show that the durations of action potentials in the motor neurons of this jellyfish are negatively correlated with the amplitude of excitatory junctional potentials. We present data from in vitro voltage-clamp experiments showing that short duration voltage spikes, which elicit large excitatory junctional potentials in vivo, produce larger and briefer calcium currents than do long duration action potentials, which elicit small excitatory junctional potentials.

  5. Action potential shape change in an electrically coupled network during propagation: a computer simulation.

    PubMed

    Buckingham, Steven D; Spencer, Andrew N

    2008-06-01

    We applied compartmental computer modeling to test a model of spike shape change in the jellyfish, Polyorchis penicillatus, to determine whether adaptive spike shortening can be attributed to the inactivation properties of a potassium channel. We modeled the jellyfish outer nerve-ring as a continuous linear segment, using ion channel and membrane properties derived in earlier studies. The model supported action potentials that shortened as they propagated away from the site of initiation and this was found to be largely independent of potassium channel inactivation. Spike broadening near the site of initiation was found to be due to a depolarization plateau that collapsed as two spikes spread from the point of initiation. The lifetime of this plateau was found to depend critically on the inward current flux and the space constant of the membrane. These data suggest that the spike shape changes may be due not only to potassium channel inactivation, but also to the passive properties of the membrane.

  6. Advances in fluorescent protein technology.

    PubMed

    Shaner, Nathan C; Patterson, George H; Davidson, Michael W

    2007-12-15

    Current fluorescent protein (FP) development strategies are focused on fine-tuning the photophysical properties of blue to yellow variants derived from the Aequorea victoria jellyfish green fluorescent protein (GFP) and on the development of monomeric FPs from other organisms that emit in the yellow-orange to far-red regions of the visible light spectrum. Progress toward these goals has been substantial, and near-infrared emitting FPs may loom over the horizon. The latest efforts in jellyfish variants have resulted in new and improved monomeric BFP, CFP, GFP and YFP variants, and the relentless search for a bright, monomeric and fast-maturing red FP has yielded a host of excellent candidates, although none is yet optimal for all applications. Meanwhile, photoactivatable FPs are emerging as a powerful class of probes for intracellular dynamics and, unexpectedly, as useful tools for the development of superresolution microscopy applications.

  7. 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.

  8. 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.

  9. 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.

  10. Making genes green: creating green fluorescent protein (GFP) fusions with blunt-end PCR products.

    PubMed

    Lo, W; Rodgers, W; Hughes, T

    1998-07-01

    The jellyfish green fluorescent protein (GFP) has proven to be a useful tool in protein localization and trafficking studies. Fused to GFP, a protein of interest can be visualized and tracked in vivo through fluorescence microscopy. However, the process of making these fusion proteins is often tedious and painstaking. Here, we describe a simple and quick method for creating GFP fusion proteins using blunt-end PCR product ligation.

  11. 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

  12. Environmental Assessment for Destin 4th of July Fireworks and Beach Cleanup

    DTIC Science & Technology

    2008-06-01

    Leatherback turtles feed primarily on jellyfish but will occasionally eat sea urchins , squid, tunicates, fish, blue-green algae, and floating...will arrive at the Community Beach Center. After the day’s sea turtle survey is complete, a crew of four people, using pre- designated access routes...the night. Staff will be briefed to use minimal to no light on the beach due to sea turtle concerns. In addition to the setup, a preliminary trash

  13. Environmental Assessment for Testing of the Network Embedded Systems Technology (NEST) at Eglin Air Force Base

    DTIC Science & Technology

    2004-08-01

    green sea turtle (Chelonia mydas) is a federally and state-listed endangered species. Green sea turtles are mainly herbivores , feeding on marine algae...1994). Green sea turtles are the only sea turtles that, as adults, are strict herbivores . Green sea turtles mature in the range of 10 to 24 years...650 to 1,200 pounds (295 to 545 kilograms [kg]) (Bronsgerma 1976). Leatherbacks are omnivorous , with a diet consisting of sea grasses, jellyfish

  14. 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

  15. 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.

  16. Biomimetic and Live Medusae Reveal the Mechanistic Advantages of a Flexible Bell Margin

    DTIC Science & Technology

    2012-11-07

    Villanueva5, John B. Blottman6, Brad J. Gemmell2, Shashank Priya5 1 Marine Biology /Environmental Sciences, Roger Williams University, Bristol, Rhode...Island, United States of America, 2 Whitman Center, Marine Biological Laboratory, Woods Hole, Massachusetts, United States of America, 3 Biology ... biology of jellyfish. We thank the New England Aquarium for their contributions of cultured medusae. Author Contributions Conceived and designed the

  17. 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

  18. 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.

  19. Regulation of Growth and Metastases in an Estrogen Independent Breast Cancer Cell by Vitamin D Compounds

    DTIC Science & Technology

    2000-08-01

    micrometastases in the nude mouse, we used the EGFP fluorescent marker gene, cloned from the bioluminescent jellyfish Aequorea Victoria (previously...Utilizing our SUM-159PT GFP model system in vivo we can more efficiently examine the effects of vitamin D compounds to modulate invasion and metastasis...cells in nude mice. We previously reported that use of SUM-159PT cells expressing GFP enabled visualization of cancer cells in the mammary fat pad as

  20. Regulation of Growth and Metastases in an Estrogen Independent Breast Cancer Cell by Vitamin D Compounds

    DTIC Science & Technology

    2001-08-01

    jellyfish Aequorea Victoria (previously described in original grant proposal). Orthotopic implantation of SUMp159PTGFP was carried out to allow for the...metastatic expression of the inoculated cells in nude mice. We previously reported that use of SUM-159PT cells expressing GFP enabled visualization of...the brain and kidney. Resolution of SUM- 159PTGF cells was down to the single cell level, and high-level GFP expression was maintained in primary

  1. 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.

  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. Studies on the Biology, Venom and Ultrastructure of Selected Venomous Fishes, Including the Scorpionfishes and Stingrays.

    DTIC Science & Technology

    1980-04-25

    and venous pressures; respirations ; and blood pH, P02 , PC0 2 and hematocrit; and total serum protein. The results indicated a fairly consistent...by the jellyfish Pelagia noctiluca in the Adriatic. -------. ... . Abstract of the 6th International Symposium on Animal, Plant and Microbial Toxins...designed to study hypotension was employed to measure arterial and venous pressures/’ respirations ; and blood pH, P02, PC02 and hematocrit; and total

  4. 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.

  5. Nematocyst discharge in Pelagia noctiluca (Cnidaria, Scyphozoa) oral arms can be affected by lidocaine, ethanol, ammonia and acetic acid.

    PubMed

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

    2014-06-01

    Nematocyst discharge and concomitant delivery of toxins is triggered to perform both defence and predation strategies in Cnidarians, and may lead to serious local and systemic reactions in humans. Pelagia noctiluca (Cnidaria, Scyphozoa) is a jellyfish particularly abundant in the Strait of Messina (Italy). After accidental contact with this jellyfish, not discharged nematocysts or even fragments of tentacles or oral arms may tightly adhere to the human skin and, following discharge, severely increase pain and the other adverse consequences of the sting. The aim of the present study is to verify if the local anesthetic lidocaine and other compounds, like alcohols, acetic acid and ammonia, known to provide pain relief after jellyfish stings, may also affect in situ discharge of nematocysts. Discharge was induced by a combined physico-chemical stimulation of oral arms by chemosensitizers (such as N-acetylated sugars, aminoacids, proteins and nucleotides), in the presence or absence of 1% lidocaine, 70% ethanol, 5% acetic acid or 20% ammonia, followed by mechanical stimulation by a non-vibrating test probe. The above mentioned compounds failed to induce discharge per se, and dramatically impaired the chemosensitizer-induced discharge response. We therefore suggest that prompt local treatment of the stung epidermis with lidocaine, acetic acid, ethanol and ammonia may provide substantial pain relief and help in reducing possible harmful local and systemic adverse reaction following accidental contact with P. noctiluca specimens.

  6. 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.

  7. Marine Neurotoxins: Envenomations and Contact Toxins.

    PubMed

    Watters, Michael R.; Stommel, Elijah W.

    2004-03-01

    Familiarity with the appearance and habitat of venomous sea creatures, the location of their stinging apparatus, and surveillance of population concentrations within recreational waters are essential in avoiding envenomations. Compared with the thermo-stable low molecular weighted ingestible seafood toxins, venomous toxins are often large molecular weight proteins and many are heat labile, which provides opportunity for therapeutic intervention. Heat therapy may denature the toxins, and provide immediate relief of pain in coelenterate and venomous fish envenomations. Injections of local anesthetic agents may also be used. First aid measures at the seashore may limit the spread of venom, and include immobilization of the affected sites, compression bandaging, and venous-lymphatic occlusive bandages. Measures to limit continued envenomation by attached stinging cells include topical vinegar for jellyfish tentacles and irrigation with debridment for spines of venomous fish. Antivenins are of limited availability and may be used for envenomations with sea snakes, Chironex box jellyfish, and some venomous fish. Sea snakes bites may be treated with antivenin from land snakes or with hemodialysis when antivenin is not available. Neuromuscular paralysis occurs with bites by sea snakes, cone snails, blue octopuses, and some jellyfish. Supportive treatment includes attention to cardiopulmonary resuscitation and intubation. Exposure to Pfeisteria may result in cognitive and behavioral abnormalities. Treatment with cholestyramine may be helpful in binding the toxin and improve recovery.

  8. Role of Pax genes in eye evolution: a cnidarian PaxB gene uniting Pax2 and Pax6 functions.

    PubMed

    Kozmik, Zbynek; Daube, Michael; Frei, Erich; Norman, Barbara; Kos, Lidia; Dishaw, Larry J; Noll, Markus; Piatigorsky, Joram

    2003-11-01

    PaxB from Tripedalia cystophora, a cubomedusan jellyfish possessing complex eyes (ocelli), was characterized. PaxB, the only Pax gene found in this cnidarian, is expressed in the larva, retina, lens, and statocyst. PaxB contains a Pax2/5/8-type paired domain and octapeptide, but a Pax6 prd-type homeodomain. Pax2/5/8-like properties of PaxB include a DNA binding specificity of the paired domain, activation and inhibitory domains, and the ability to rescue spa(pol), a Drosophila Pax2 eye mutant. Like Pax6, PaxB activates jellyfish crystallin and Drosophila rhodopsin rh6 promoters and induces small ectopic eyes in Drosophila. Pax6 has been considered a "master" control gene for eye development. Our data suggest that the ancestor of jellyfish PaxB, a PaxB-like protein, was the primordial Pax protein in eye evolution and that Pax6-like genes evolved in triploblasts after separation from Cnidaria, raising the possibility that cnidarian and sophisticated triploblastic eyes arose independently.

  9. Can gelatinous zooplankton influence the fate of crude oil in marine environments?

    PubMed

    Gemmell, Brad J; Bacosa, Hernando P; Liu, Zhanfei; Buskey, Edward J

    2016-12-15

    Gelatinous zooplankton are known for their capacity to excrete copious amounts of mucus that can be utilized by other organisms. The release of mucus is exacerbated by stressful conditions. Despite the recognized importance of cnidarian mucus to production and material flux in marine ecosystems, the role of gelatinous zooplankton in influencing the fate of oil spills is unknown. In this study we used laboratory experiments to observe the influence of mucus from the moon jellyfish (Aurelia aurita) on the aggregation and degradation of crude oil. The results show that jellyfish swimming in a dispersed solution of oil droplets produced copious amounts of mucus and the mucus aggregates that were shed by the animals contained 26 times more oil than the surrounding water. Incubation experiments showed that hydrocarbon degrading bacteria cell densities more than doubled in the presence of mucus and after 14days, resulted in a significant increase in oil degradation. These results suggest that jellyfish can aggregate dispersed oil droplets and embed them within a matrix that favors hydrocarbon degrading bacteria. While this study lends support to the hypothesis that the presence of gelatinous zooplankton can impact oil spills large scale mesocosm studies will be needed to fully quantify the influence on a natural system.

  10. 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.

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

    PubMed

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

    2012-01-01

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

  12. No observable effect of a glyphosate-based herbicide on two top predators of temporal water bodies.

    PubMed

    Ujszegi, János; Gál, Zoltán; Mikó, Zsanett; Hettyey, Attila

    2015-02-01

    It has been implied that the application of pesticides is involved in the world-wide decline of biodiversity, but little is known about the influence of these chemicals on key predators of temporary wetlands. The direct impacts were examined of a frequently applied glyphosate-based herbicide on larval Aeshna cyanea (Müller, 1764; Odonata, Insecta) and adult male Lissotriton vulgaris (Linnaeus, 1758; Caudata, Amphibia), 2 top predators of Central European ephemeral ponds. The effects of herbicide exposure were measured on survival, behavior, body mass change, and predatory activity in an outdoor mesocosm experiment lasting for 17 d. No significant effects of exposure were observed in either predator species. The results suggest that the herbicide has no immediate effect on the predators studied at environmentally relevant concentrations and that these predators can also fulfill their top-down regulatory role in contaminated ecosystems.

  13. The Role of Mosquitoes in the Diet of Adult Dragon and Damselflies (Odonata).

    PubMed

    Pfitzner, Wolf Peter; Beck, Matthias; Weitzel, Thomas; Becker, Norbert

    2015-06-01

    The flood plains of the Upper Rhine Valley provide excellent conditions for the proliferation of mosquitoes as well as for the development of dragon and damselflies. It could be assumed that mosquitoes belong to the diet of the Odonata and that the latter could be harmed by the reduction of the mosquito population with the purpose of diminishing the massive nuisance for the people living there. A total of 41 adult dragonflies and damselflies were examined by immunoblot for remnants of mosquitoes in their guts. A rabbit antiserum against Aedes vexans proteins was used for the immunoblot. Only 3 Aeshna cyanea and 1 Platycnemis pennipes could be shown to have fed on mosquitoes. In specimens of the genus Sympetrum no mosquitoes were detected. It seems very doubtful that mosquitoes are an essential part of the Odonata diet.

  14. Template-based automatic recognition of birdsong syllables from continuous recordings.

    PubMed

    Anderson, S E; Dave, A S; Margoliash, D

    1996-08-01

    The application of dynamic time warping (DTW) to the automated analysis of continuous recordings of animal vocalizations is evaluated. The DTW algorithm compares an input signal with a set of predefined templates representative of categories chosen by the investigator. It directly compares signal spectrograms, and identifies constituents and constituent boundaries, thus permitting the identification of a broad range of signals and signal components. When applied to vocalizations of an indigo bunting (Passerina cyanea) and a zebra finch (Taeniopygia guttata) collected from a low-clutter, low-noise environment, the recognizer identifies syllables in stereotyped songs and calls with greater than 97% accuracy. Syllables of the more variable and lower amplitude indigo bunting plastic song are identified with approximately 84% accuracy. Under restricted recordings conditions, this technique apparently has general applicability to analysis of a variety of animal vocalizations and can dramatically decrease the amount of time spent on manual identification of vocalizations.

  15. Spatio-temporal changes in the genetic structure of the Passerina bunting hybrid zone.

    PubMed

    Carling, Matthew D; Zuckerberg, Benjamin

    2011-03-01

    Although theoretical models predict that the structure of a hybrid zone can change under a variety of scenarios, only a few empirical studies of hybrid zones have unequivocally demonstrated zone movement. These studies are rare because few data sets exist that include repeated, temporally spaced, samples of the same hybrid zone. We analysed mitochondrial DNA haplotype data from samples separated by 40-45 years from across the Passerina amoena (Lazuli Bunting) and Passerina cyanea (Indigo Bunting) hybrid zone to investigate whether the genetic structure of this zone has changed during that interval. Both cline and generalized linear mixed modelling analyses uncovered a significant narrowing and a substantial westward shift of the Passerina bunting hybrid zone, clearly illustrating hybrid zone movement. The cause of the change may be due to a combination of ecological, demographic and behavioural factors. Our results predict that the width of the hybrid zone will continue to narrow over time, a finding consistent with reinforcement theory.

  16. Referential gestures in fish collaborative hunting.

    PubMed

    Vail, Alexander L; Manica, Andrea; Bshary, Redouan

    2013-01-01

    In humans, referential gestures intentionally draw the attention of a partner to an object of mutual interest, and are considered a key element in language development. Outside humans, referential gestures have only been attributed to great apes and, most recently, ravens. This was interpreted as further evidence for the comparable cognitive abilities of primates and corvids. Here we describe a signal that coral reef fishes, the grouper Plectropomus pessuliferus marisrubri and coral trout Plectropomus leopardus, use to indicate hidden prey to cooperative hunting partners, including giant moray eels Gymnothorax javanicus, Napoleon wrasses Chelinus undulatus and octopuses Octopus cyanea. We provide evidence that the signal possesses the five attributes proposed to infer a referential gesture: it is directed towards an object, mechanically ineffective, directed towards a potential recipient, receives a voluntary response and demonstrates hallmarks of intentionality. Thus, referential gesture use is not restricted to large-brained vertebrates.

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

    PubMed Central

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

    2012-01-01

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

  18. Fast-swimming hydromedusae exploit velar kinematics to form an optimal vortex wake.

    PubMed

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

    2006-06-01

    Fast-swimming hydromedusan jellyfish possess a characteristic funnel-shaped velum at the exit of their oral cavity that interacts with the pulsed jets of water ejected during swimming motions. It has been previously assumed that the velum primarily serves to augment swimming thrust by constricting the ejected flow in order to produce higher jet velocities. This paper presents high-speed video and dye-flow visualizations of free-swimming Nemopsis bachei hydromedusae, which instead indicate that the time-dependent velar kinematics observed during the swimming cycle primarily serve to optimize vortices formed by the ejected water rather than to affect the speed of the ejected flow. Optimal vortex formation is favorable in fast-swimming jellyfish because, unlike the jet funnelling mechanism, it allows for the minimization of energy costs while maximizing thrust forces. However, the vortex ;formation number' corresponding to optimality in N. bachei is substantially greater than the value of 4 found in previous engineering studies of pulsed jets from rigid tubes. The increased optimal vortex formation number is attributable to the transient velar kinematics exhibited by the animals. A recently developed model for instantaneous forces generated during swimming motions is implemented to demonstrate that transient velar kinematics are required in order to achieve the measured swimming trajectories. The presence of velar structures in fast-swimming jellyfish and the occurrence of similar jet-regulating mechanisms in other jet-propelled swimmers (e.g. the funnel of squid) appear to be a primary factor contributing to success of fast-swimming jetters, despite their primitive body plans.

  19. 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

  20. 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.

  1. 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.

  2. Marine and Other Aquatic Dermatoses

    PubMed Central

    Sridhar, Surg Capt. Jandhyala; Deo, Surg Cdr. Rajeev

    2017-01-01

    Occupational and recreational aquatic activity predisposes our population to a wide variety of dermatoses. Sunburn, urticaria, jellyfish stings, and contact dermatitis to rubber equipment are common allergies that are encountered in the aquatic environment. Among the infections, tinea versicolor, intertrigo, and verruca vulgaris are widespread. Swimmer's itch may occur due to skin penetration by schistosome cercariae, while free-floating nematocysts of marine coelenterates may precipitate seabather's eruption. “Suit squeeze” due to cutaneous barotrauma and lymphoedematous peau d’orange due to decompression are rare, described entities. This review serves as a ready reckoner for Indian dermatologists and medical practitioners to identify and manage these conditions. PMID:28216728

  3. Marine and Other Aquatic Dermatoses.

    PubMed

    Sridhar, Surg Capt Jandhyala; Deo, Surg Cdr Rajeev

    2017-01-01

    Occupational and recreational aquatic activity predisposes our population to a wide variety of dermatoses. Sunburn, urticaria, jellyfish stings, and contact dermatitis to rubber equipment are common allergies that are encountered in the aquatic environment. Among the infections, tinea versicolor, intertrigo, and verruca vulgaris are widespread. Swimmer's itch may occur due to skin penetration by schistosome cercariae, while free-floating nematocysts of marine coelenterates may precipitate seabather's eruption. "Suit squeeze" due to cutaneous barotrauma and lymphoedematous peau d'orange due to decompression are rare, described entities. This review serves as a ready reckoner for Indian dermatologists and medical practitioners to identify and manage these conditions.

  4. 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.

  5. Evolutionary crossroads in developmental biology: Cnidaria.

    PubMed

    Technau, Ulrich; Steele, Robert E

    2011-04-01

    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.

  6. 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

  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

    2015-10-29

    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.

  9. Aequorin-expressing yeast emits light under electric control.

    PubMed

    Vilanova, Cristina; Hueso, Angeles; Palanca, Carles; Marco, Guillem; Pitarch, Miguel; Otero, Eduardo; Crespo, Juny; Szablowski, Jerzy; Rivera, Sara; Domínguez-Escribà, Laura; Navarro, Emilio; Montagud, Arnau; de Córdoba, Pedro Fernández; González, Asier; Ariño, Joaquín; Moya, Andrés; Urchueguía, Javier; Porcar, Manuel

    2011-03-20

    In this study, we show the use of direct external electrical stimulation of a jellyfish luminescent calcium-activated protein, aequorin, expressed in a transgenic yeast strain. Yeast cultures were electrically stimulated through two electrodes coupled to a standard power generator. Even low (1.5 V) electric pulses triggered a rapid light peak and serial light pulses were obtained after electric pulses were applied periodically, suggesting that the system is re-enacted after a short refraction time. These results open up a new scenario, in the very interphase between synthetic biology and cybernetics, in which complex cellular behavior might be subjected to electrical control.

  10. Aequorea victoria bioluminescence moves into an exciting new era.

    PubMed

    Kendall, J M; Badminton, M N

    1998-05-01

    Bioluminescence has revolutionized research into many cellular and molecular-biological processes, ranging from intracellular signalling to gene transcription. This article focuses on the chemistry and biotechnological exploitation of the two proteins involved in bioluminescence of the jellyfish Aequorea victoria--aequorin and green fluorescent protein. Engineered recombinant aequorin has led to a novel technological approach to monitoring calcium signals in organelles and subcellular domains. A new generation of intracellular calcium indicators has been produced in which engineered variants of green fluorescent protein are used to probe their ionic environment using intramolecular fluorescence-resonance-energy transfer.

  11. Preparation and initial characterization of crystals of the photoprotein aequorin from Aequorea victoria.

    PubMed

    Hannick, L I; Prasher, D C; Schultz, L W; Deschamps, J R; Ward, K B

    1993-01-01

    Crystals of recombinant aequorin, the photoprotein from the jellyfish Aequorea victoria, have been grown from solutions containing sodium phosphate. The crystals grow as thin plates which diffract to beyond 2.2 A resolution. The crystals are orthorhombic, space group P2(1)2(1)2(1); the axes are a = 89.1(1), b = 88.4(1), and c = 52.7(1) A. The asymmetric unit contains two molecules. Crystals exposed to calcium ion solutions emit a steady glow and slowly deteriorate, confirming that the crystals consist of a charged, competent photoprotein. This represents the first successful preparation of single crystals of a photoprotein suitable for diffraction analysis.

  12. Imaging individual green fluorescent proteins

    NASA Astrophysics Data System (ADS)

    Pierce, Daniel W.; Hom-Booher, Nora; Vale, Ronald D.

    1997-07-01

    Recent advances in fluorescence microscopy techniques have allowed the video-time imaging of single molecules of fluorescent dyes covalently bound to proteins in aqueous environments. However, the techniques have not been exploited fully because proteins can be difficult to label, and dye modification may cause partial or complete loss of activity. These difficulties could be circumvented by fusing proteins to green fluorescent protein (GFP) of the jellyfish Aequorea victoria. Here we report that single S65T mutant GFP molecules can be imaged using total internal reflection microscopy, and that ATP-driven movement of an individual kinesin molecule (a microtubule motor protein) fused to GFP can be readily observed.

  13. 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.

  14. Monitoring yeast intracellular Ca2+ levels using an in vivo bioluminescence assay.

    PubMed

    Tisi, Renata; Martegani, Enzo; Brandão, Rogelio L

    2015-02-02

    This protocol describes the use of the jellyfish Aequorea victoria aequorin protein to measure Ca(2+) levels in living yeast cells. All yeast strains to be analyzed must express the A. victoria apoprotein of the aequorin calcium biosensor, to be reconstituted into fully active aequorin by association with its cofactor, coelenterazine, which cannot be synthesized by yeast itself. The simplest way to achieve reconstitution is to transform yeast cells with a vector driving apoaequorin expression, and then supply commercially available coelenterazine cofactor in the medium. Coelenterazine is a hydrophobic molecule and is able to permeate yeast cells.

  15. Using targeted variants of aequorin to measure Ca2+ levels in intracellular organelles.

    PubMed

    Granatiero, Veronica; Patron, Maria; Tosatto, Anna; Merli, Giulia; Rizzuto, Rosario

    2014-01-01

    Aequorin is a Ca(2+)-sensitive photoprotein isolated from the jellyfish Aequorea victoria. It is an ideal probe for measuring Ca(2+) concentration ([Ca(2+)]) in intracellular organelles because it can be modified to include specific targeting sequences. On the binding of Ca(2+) to three high-affinity sites in aequorin, an irreversible reaction occurs in which the prosthetic group coelenterazine is released and a photon is emitted. This protocol presents procedures for expressing, targeting, and reconstituting aequorin in intact and permeabilized mammalian cells and describes how to use this photoprotein to measure intracellular [Ca(2+)] in various subcellular compartments.

  16. [Fluorescent proteins: physical-chemical properties and application in cell biology].

    PubMed

    Stepanenko, O V; Verkhusha, V V; Kuznetsova, I M; Turoverov, K K

    2007-01-01

    Green fluorescent protein (GFP) from jellyfish Aequorea victoria is the most extensively studied and widely used in cell biology protein. At present novel naturally occurring GFP-like proteins have been discovered and enhanced mutants of Aequorea GFP have been created. These mutants differ from wild-type GFP by stability, value of quantum yield, absorption and fluorescence spectra position and photochemical properties. GFP-like proteins are the fast growing family. This review is an attempt to characterize the main groups of GFP-like proteins, describe their structure and mechanisms of chromophore formation and summarize the main trends of their utilization as markers and biosensors in cell and molecular biology.

  17. 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.

  18. GASP: Gas stripping and the outskirts of galaxies as a function of environment

    NASA Astrophysics Data System (ADS)

    Poggianti, Bianca; GASP Team

    2017-03-01

    We present GASP, an ongoing ESO Large Program with MUSE aiming to study gas removal processes from galaxies at low redshift. GASP targets 100 galaxies with tails, tentacles and one-sided debris. MUSE data allows a detailed investigation of the ionized stripped gas, as well as of the gas and stars within the galaxy out to large distances from the galaxy center. We show the first results for two of the GASP galaxies that are striking cluster jellyfish galaxies of stellar masses ~ 1011 M ⊙.

  19. 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.

  20. 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.

  1. 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

  2. Effects of Modified Handling on the Physiological Stress of Trawled-and-Discarded Yellowfin Bream (Acanthopagrus australis).

    PubMed

    Uhlmann, Sven Sebastian; Broadhurst, Matt Kenyon; Millar, Russell Brian

    2015-01-01

    Modified handling is often claimed to reduce (sub-)lethal impacts among organisms caught-and-released in fisheries. Improving welfare of discarded fish warrants investigation, when their survival is of both economic and ecological importance. In this study, juvenile yellowfin bream (Acanthopagrus australis) were trawled in an Australian penaeid fishery and then discarded after on-board sorting in either dry or water-filled (modified) trays and with delays in starting sorting of either 2 or 15 mins. Blood plasma cortisol, glucose and potassium were sampled immediately from some yellowfin bream, while others were placed into cages (with controls) and sampled after five days. Irrespective of their on-board handling, all trawled fish incurred a relatively high acute stress response (i.e. an increase in Mean ± SE cortisol from a baseline of <4 to 122.0 ± 14.9 ng/mL) that was mostly attributed to the trawling process, and exacerbated by variation in key parameters (low salinity, changes in water temperature and the presence of jellyfish Catostylus mosaicus in catches). When C. mosaicus was present, the potassium concentrations of fish sampled immediately after sorting were significantly elevated, possibly due to nematocyst contact and subsequent inhibition of ion pumps or cytolysis. Stress also increased during handling in response to warmer air temperatures and longer exposure. While most fish had substantially recovered by 120 hours after discarding, deploying selective trawls (to reduce jellyfish) for short periods and then quickly sorting catches in water would benefit discard welfare.

  3. Preparation of nitrogen-doped graphene sheets by a combined chemical and hydrothermal reduction of graphene oxide.

    PubMed

    Long, Donghui; Li, Wei; Ling, Licheng; Miyawaki, Jin; Mochida, Isao; Yoon, Seong-Ho

    2010-10-19

    Nitrogen-doped graphene sheets were prepared through a hydrothermal reduction of colloidal dispersions of graphite oxide in the presence of hydrazine and ammonia at pH of 10. The effect of hydrothermal temperature on the structure, morphology, and surface chemistry of as-prepared graphene sheets were investigated though XRD, N(2) adsorption, solid-state (13)C NMR, SEM, TEM, and XPS characterizations. Oxygen reduction and nitrogen doping were achieved simultaneously under the hydrothermal reaction. Up to 5% nitrogen-doped graphene sheets with slightly wrinkled and folded feature were obtained at the relative low hydrothermal temperature. With the increase of hydrothermal temperature, the nitrogen content decreased slightly and more pyridinic N incorporated into the graphene network. Meanwhile, a jellyfish-like graphene structure was formed by self-organization of graphene sheets at the hydrothermal temperature of 160 °C. Further increase of the temperature to 200 °C, graphene sheets could self-aggregate into agglomerate particles but still contained doping level of 4 wt % N. The unique hydrothermal environment should play an important role in the nitrogen doping and the jellyfish-like graphene formation. This simple hydrothermal method could provide the synthesis of nitrogen-doped graphene sheets in large scale for various practical applications.

  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.

  5. High-fidelity simulations of simple models of biomorphic aquatic locomotion

    NASA Astrophysics Data System (ADS)

    Eldredge, Jeff; Hector, Daniel; Wilson, Megan

    2007-11-01

    Aquatic creatures self-propel and maneuver with an incredible diversity of mechanics, even at the moderate Reynolds numbers appropriate for bio-inspired autonomous vehicles. In this work, we explore simple two-dimensional abstractions of two such mechanisms---undulatory and jellyfish-like locomotion---effected by prescribed hinge motion in articulated rigid body systems. These mechanisms are explored using a high-fidelity Navier-Stokes solver based on the viscous vortex particle method, strongly coupled with the rigid-body dynamics of the system. Such coupling enables an investigation of untethered swimming and maneuvering, which is essential for developing reduced-order models for motion planning and control. In the case of undulatory locomotion, it is shown that swimming effectiveness depends on both the relative phase and amplitude of the oscillatory hinge motions. The optimal shape control at these finite Reynolds numbers is contrasted with optima found for zero Reynolds number and inviscid swimmers. The jellyfish motion is enabled by periodic contractions of the bell shape, adapted from experimentally-measured kinematics of medusan swimmers (Dabiri et al., J. Exp. Biol., 2005). The vortex formation processes, energy budgets and fluid forces are explored for their relationship with forward propulsion.

  6. Lagrangian studies of animal swimming and aquatic predator-prey interactions

    NASA Astrophysics Data System (ADS)

    Dabiri, John

    2008-03-01

    Experimental studies of animal swimming have been traditionally based on an Eulerian perspective in which the time-dependent flow field surrounding the animal is measured at fixed locations in space. The measured velocity field and its derivatives (e.g. vorticity) can, in principle, be used to deduce the forces, energetics, and fluid transport associated with locomotion in real fluids. However, achieving a connection between measurements of these Eulerian fields and the dynamics of locomotion has proven difficult in practice. We present the application of Lagrangian methods of flow analysis in which the time-dependent trajectories of individual tracer particles in the flow are measured experimentally and subsequently interrogated using dynamical systems tools in order to quantitatively resolve the dynamics of animal swimming. The Lagrangian methods are shown to be readily extended to time-dependent measurements in three spatial dimensions and to in situ field measurements using a recently developed self-contained underwater velocimetry apparatus (SCUVA). Case studies of jellyfish and other aquatic animals observed in the laboratory and in marine environments are used to illustrate the proposed approach. We also show that predator-prey interactions during jellyfish swimming can be addressed using the aforementioned Lagrangian methods in combination with the Maxey-Riley equations for inertial particles in fluid flow.

  7. 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.

  8. QM/MM study on the light emitters of aequorin chemiluminescence, bioluminescence, and fluorescence: a general understanding of the bioluminescence of several marine organisms.

    PubMed

    Chen, Shu-Feng; Ferré, Nicolas; Liu, Ya-Jun

    2013-06-24

    Aequorea victoria is a type of jellyfish that is known by its famous protein, green fluorescent protein (GFP), which has been widely used as a probe in many fields. Aequorea has another important protein, aequorin, which is one of the members of the EF-hand calcium-binding protein family. Aequorin has been used for intracellular calcium measurements for three decades, but its bioluminescence mechanism remains largely unknown. One of the important reasons is the lack of clear and reliable knowledge about the light emitters, which are complex. Several neutral and anionic forms exist in chemiexcited, bioluminescent, and fluorescent states and are connected with the H-bond network of the binding cavity in the protein. We first theoretically investigated aequorin chemiluminescence, bioluminescence, and fluorescence in real proteins by performing hybrid quantum mechanics and molecular mechanics methods combined with a molecular dynamics method. For the first time, this study reported the origin and clear differences in the chemiluminescence, bioluminescence and fluorescence of aequorin, which is important for understanding the bioluminescence not only of jellyfish, but also of many other marine organisms (that have the same coelenterazine caved in different coelenterazine-type luciferases).

  9. Field and laboratory observations on predation and prey selectivity of the scyphomedusa Chrysaora cf. caliparea in Southeast Indian waters

    NASA Astrophysics Data System (ADS)

    Kanagaraj, Govindan; Ezhilarasan, Pazhaniyappan; Sampathkumar, Pitchai; Morandini, André C.; Sivakumar, Velayudhan Pillai

    2011-03-01

    Chrysaora cf. caliparea, one of the most abundant medusae species in India, seems to be an important predator in the coastal waters of Bay of Bengal. The ability of Chrysaora cf. caliparea to feed at maximum rate in high prey concentrations implies that this jellyfish can efficiently exploit dense prey patches, at least for a short period. This study presents preliminary information regarding digestion and feeding rate upon copepods in a warm water environment. The ingestion rate of the average-sized medusae Chrysaora cf. caliparea is well balanced in nature, which in turn implies that this jellyfish is tuned for optimal utilization of available prey resources. Comparison with earlier research indicates that prey escape speed is one important factor governing which prey will be captured. A full understanding of predation mechanics awaits further investigation of both predator and prey behavior. However, because of the scarcity of long-term quantitative population data most insights have to be made indirectly. Nevertheless, low abundance of Chrysaora cf. caliparea in the water column during summer (May 2007) and the overall annual abundance seem not to considerably affect the zooplankton population, especially copepods. The present work contributes to the knowledge of prey-predator relationship of the forgotten fauna in Indian waters, which is especially crucial for understanding the process of ecological recovery of coastal water environment.

  10. 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.

  11. Interactions of cnidarian toxins with the immune system.

    PubMed

    Suput, Dusan

    2011-10-01

    Cnidarians comprise four classes of toxic marine animals: Anthozoa, Cubozoa, Scyphozoa and Hydrozoa. They are the largest and probably the oldest phylum of toxic marine animals. Any contact with a cnidarian, especially the box jellyfish (Chironex fleckeri), can be fatal, but most cnidarians do not possess sufficiently strong venomous apparatus to penetrate the human skin, whereas others rarely come into contact with human beings. Only a small, almost negligible percentage of the vast wealth of cnidarian toxins has been studied in detail. Many polypeptide cnidarian toxins are immunogenic, and cross-reactivity between several jellyfish venoms has been reported. Cnidarians also possess components of innate immunity, and some of those components have been preserved in evolution. On the other hand, cnidarian toxins have already been used for the design of immunotoxins to treat cancer, whereas other cnidarian toxins can modulate the immune system in mammals, including man. This review will focus on a short overview of cnidarian toxins, on the innate immunity of cnidarians, and on the mode of action of cnidarian toxins which can modulate the immune system in mammals. Emphasis is palced on those toxins which block voltage activated potassium channels in the cells of the immune system.

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

    PubMed

    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.

  13. 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.

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

    PubMed

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

    2016-04-05

    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.

  15. 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.

  16. 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.

  17. The positive side of a negative reference: the delay between linguistic processing and common ground

    PubMed Central

    Noveck, Ira; Rivera, Natalia; Jaume-Guazzini, Francisco

    2017-01-01

    Interlocutors converge on names to refer to entities. For example, a speaker might refer to a novel looking object as the jellyfish and, once identified, the listener will too. The hypothesized mechanism behind such referential precedents is a subject of debate. The common ground view claims that listeners register the object as well as the identity of the speaker who coined the label. The linguistic view claims that, once established, precedents are treated by listeners like any other linguistic unit, i.e. without needing to keep track of the speaker. To test predictions from each account, we used visual-world eyetracking, which allows observations in real time, during a standard referential communication task. Participants had to select objects based on instructions from two speakers. In the critical condition, listeners sought an object with a negative reference such as not the jellyfish. We aimed to determine the extent to which listeners rely on the linguistic input, common ground or both. We found that initial interpretations were based on linguistic processing only and that common ground considerations do emerge but only after 1000 ms. Our findings support the idea that—at least temporally—linguistic processing can be isolated from common ground. PMID:28386440

  18. Late summer zoogeography of the northern Bering and Chukchi seas

    NASA Astrophysics Data System (ADS)

    Sigler, Michael F.; Mueter, Franz J.; Bluhm, Bodil A.; Busby, Morgan S.; Cokelet, Edward D.; Danielson, Seth L.; Robertis, Alex De; Eisner, Lisa B.; Farley, Edward V.; Iken, Katrin; Kuletz, Kathy J.; Lauth, Robert R.; Logerwell, Elizabeth A.; Pinchuk, Alexei I.

    2017-01-01

    Ocean currents, water masses, and seasonal sea ice formation contribute to determining relationships among the biota of the Bering and Chukchi seas. The Bering Sea communicates with the Chukchi Sea via northward advection of water, nutrients, organic matter, and plankton through Bering Strait. We used data from concurrent surveys of zooplankton, pelagic fishes and jellyfish, epibenthic fishes and invertebrates, and seabirds to identify faunal distribution patterns and environmental factors that are related to these faunal distributions within the US portions of the Chukchi Sea shelf and Bering Sea shelf north of Nunivak Island. Regional differences in late summer (August-September) distributions of biota largely reflected the underlying hydrography. Depth, temperature, salinity, stratification, and chlorophyll a, but less so sediment-related or nutrient-related factors, were related to the distributions of the assemblages (zooplankton: depth, salinity, stratification; pelagic fishes and jellyfish: depth, stratification, chlorophyll a; epibenthic fishes and invertebrates: depth, temperature, salinity; seabirds: temperature, salinity, stratification). These six environmental factors that most influenced distributions of zooplankton, pelagic fishes/jellyfish, epibenthic fishes and invertebrate, and seabird assemblages likely can be simplified to three factors reflecting bottom depth, water mass, and their stratification and productivity (which are tightly linked in the study region). The assemblages were principally structured from nearshore to offshore and from south to north. The nearshore to offshore contrast usually was stronger in the south, where the enormous discharge of the Yukon River is more apparent and extends farther offshore, influencing zooplankton, pelagic fish/jellyfish, and seabird assemblages. Some assemblages overlapped spatially (e.g., seabird and zooplankton), indicating shared influential environmental factors or trophic linkages among

  19. Impact of forest type and management strategy on avian densities in the Mississippi Alluvial Valley, USA

    USGS Publications Warehouse

    Twedt, D.J.; Wilson, R.R.; Henne-Kerr, J.L.; Hamilton, R.B.

    1999-01-01

    Avian territory densities were determined from 20 Breeding Bird Censuses in mature (>30 years) bottomland hardwood stand: and 18 Breeding Bird Censuses in young (6-9 years old) cottonwood (Populas deltoides) plantations in the Mississippi Alluvial Valley. Avian species richness, diversity, and territory density were greater (p 0.05). Even so, detrended correspondence analysis based on avian territory densities readily segregated forest types and silvicultural treatments. Timber harvest within bottomland hardwood stands resulted in a shift in bird communities toward those found in cottonwood stands by increasing the densities of early-successional species such as Indigo Bunting (Passerina cyanea), Yellow-breasted Chat (Icteria virens), and Common Yellowthroat (Geothlypis trichas). Conversely, regenerating cottonwood stands from root sprouts, rather than planting stem cuttings, resulted in a shift in bird communities toward those found in bottomland hardwood stands by increasing densities of species such as White-eyed Vireo (Vireo griseus) and Wood Thrush (Hylocichla mustelina). Tree species diversity, angular canopy cover, and midstory density were positively associated with bird species assemblages in bottomland hardwood stands, whereas vegetation density at ground level was positively associated with bird communities in cottonwood plantations. Conversion of agricultural fields to short-rotation cottonwood plantations results in increased breeding bird populations by adding up to 140 additional territories 40 ha-1. Even so, relative conservation values, derive, from indicator species analysis and Partners in Flight concern scores, suggest that mature bottomland hardwood forests are twice as 'valuable' for bird conservation as are cottonwood plantations.

  20. Sink or swim: a test of tadpole behavioral responses to predator cues and potential alarm pheromones from skin secretions.

    PubMed

    Maag, Nino; Gehrer, Lukas; Woodhams, Douglas C

    2012-11-01

    Chemical signaling is a vital mode of communication for most organisms, including larval amphibians. However, few studies have determined the identity or source of chemical compounds signaling amphibian defensive behaviors, in particular, whether alarm pheromones can be actively secreted from tadpoles signaling danger to conspecifics. Here we exposed tadpoles of the common toad Bufo bufo and common frog Rana temporaria to known cues signaling predation risk and to potential alarm pheromones. In both species, an immediate reduction in swimming activity extending over an hour was caused by chemical cues from the predator Aeshna cyanea (dragonfly larvae) that had been feeding on conspecific tadpoles. However, B. bufo tadpoles did not detectably alter their behavior upon exposure to potential alarm pheromones, neither to their own skin secretions, nor to the abundant predator-defense peptide bradykinin. Thus, chemicals signaling active predation had a stronger effect than general alarm secretions of other common toad tadpoles. This species may invest in a defensive strategy alternative to communication by alarm pheromones, given that Bufonidae are toxic to some predators and not known to produce defensive skin peptides. Comparative behavioral physiology of amphibian alarm responses may elucidate functional trade-offs in pheromone production and the evolution of chemical communication.

  1. The relative importance of prey-borne and predator-borne chemical cues for inducible antipredator responses in tadpoles.

    PubMed

    Hettyey, Attila; Tóth, Zoltán; Thonhauser, Kerstin E; Frommen, Joachim G; Penn, Dustin J; Van Buskirk, Josh

    2015-11-01

    Chemical cues that evoke anti-predator developmental changes have received considerable attention, but it is not known to what extent prey use information from the smell of predators and from cues released through digestion. We conducted an experiment to determine the importance of various types of cues for the adjustment of anti-predator defences. We exposed tadpoles (common frog, Rana temporaria) to water originating from predators (caged dragonfly larvae, Aeshna cyanea) that were fed different types and quantities of prey outside of tadpole-rearing containers. Variation among treatments in the magnitude of morphological and behavioural responses was highly consistent. Our results demonstrate that tadpoles can assess the threat posed by predators through digestion-released, prey-borne cues and continually released predator-borne cues. These cues may play an important role in the fine-tuning of anti-predator responses and significantly affect the outcome of interactions between predators and prey in aquatic ecosystems. There has been much confusion regards terminology used in the literature, and therefore we also propose a more precise and consistent binomial nomenclature based on the timing of chemical cue release (stress-, attack-, capture-, digestion- or continually released cues) and the origin of cues (prey-borne or predator-borne cues). We hope that this new nomenclature will improve comparisons among studies on this topic.

  2. Molecular Phylogeny and Historical Biogeography of the Neotropical Swarm-Founding Social Wasp Genus Synoeca (Hymenoptera: Vespidae)

    PubMed Central

    Menezes, Rodolpho Santos Telles; Brady, Seán Gary; Carvalho, Antônio Freire; Del Lama, Marco Antonio; Costa, Marco Antônio

    2015-01-01

    The Neotropical Region harbors high biodiversity and many studies on mammals, reptiles, amphibians and avifauna have investigated the causes for this pattern. However, there is a paucity of such studies that focus on Neotropical insect groups. Synoeca de Saussure, 1852 is a Neotropical swarm-founding social wasp genus with five described species that is broadly and conspicuously distributed throughout the Neotropics. Here, we infer the phylogenetic relationships, diversification times, and historical biogeography of Synoeca species. We also investigate samples of the disjoint populations of S. septentrionalis that occur in both northwestern parts of South America through Central American and the Brazilian Atlantic rainforests. Our results showed that the interspecific relationships for Synoeca could be described as follows: (S. chalibea + S. virginea) + (S. cyanea + (S. septentrionalis/S. surinama)). Notably, samples of S. septentrionalis and S. surinama collected in the Atlantic Forest were interrelated and may be the result of incomplete lineage sorting and/or mitochondrial introgression among them. Our Bayesian divergence dating analysis revealed recent Plio-Pleistocene diversification in Synoeca. Moreover, our biogeographical analysis suggested an Amazonian origin of Synoeca, with three main dispersal events subsequently occurring during the Plio-Pleistocene. PMID:25738705

  3. The gustatory sensilla on the endophytic ovipositor of Odonata.

    PubMed

    Rebora, Manuela; Piersanti, Silvana; Dell'Otto, Alessandro; Gaino, Elda

    2013-03-01

    The present paper aims at describing the fine structure of coeloconic sensilla located on the cutting valves of the endophytic ovipositor of two Odonata species, the anisopteran Aeshna cyanea (Aeshnidae) and the zygopteran Ischnura elegans (Coenagrionidae), by carrying out parallel investigations under SEM and TEM. In both species these coeloconic sensilla are innervated by four unbranched neurons forming four outer dendritic segments enveloped by the dendrite sheath. One dendrite terminates at the base of the peg forming a well developed tubular body, while the other three enter the peg after interruption of the dendrite sheath. The cuticle of the peg shows an apical pore and a joint membrane. This last feature, together with the tubular body and the suspension fibers, represent the mechanosensory components of the sensillum while the pore and the dendrites entering the peg allow chemoreception. The ultrastructural organization of these coeloconic sensilla is in agreement with the one reported for insect gustatory sensilla. Our investigation describes for the first time typical insect gustatory sensilla in Odonata. Electrophysiological and behavioral studies are needed to verify the role that these structures can perform in sensing the egg-laying substrata.

  4. A Gibbs sampler for Bayesian analysis of site-occupancy data

    USGS Publications Warehouse

    Dorazio, Robert M.; Rodriguez, Daniel Taylor

    2012-01-01

    1. A Bayesian analysis of site-occupancy data containing covariates of species occurrence and species detection probabilities is usually completed using Markov chain Monte Carlo methods in conjunction with software programs that can implement those methods for any statistical model, not just site-occupancy models. Although these software programs are quite flexible, considerable experience is often required to specify a model and to initialize the Markov chain so that summaries of the posterior distribution can be estimated efficiently and accurately. 2. As an alternative to these programs, we develop a Gibbs sampler for Bayesian analysis of site-occupancy data that include covariates of species occurrence and species detection probabilities. This Gibbs sampler is based on a class of site-occupancy models in which probabilities of species occurrence and detection are specified as probit-regression functions of site- and survey-specific covariate measurements. 3. To illustrate the Gibbs sampler, we analyse site-occupancy data of the blue hawker, Aeshna cyanea (Odonata, Aeshnidae), a common dragonfly species in Switzerland. Our analysis includes a comparison of results based on Bayesian and classical (non-Bayesian) methods of inference. We also provide code (based on the R software program) for conducting Bayesian and classical analyses of site-occupancy data.

  5. Escape behaviour and ultimate causes of specific induced defences in an anuran tadpole.

    PubMed

    Teplitsky, C; Plenet, S; Léna, J-P; Mermet, N; Malet, E; Joly, P

    2005-01-01

    Induced defences, such as the predator avoidance morphologies in amphibians, result from spatial or temporal variability in predation risk. One important component of this variability should be the difference in hunting strategies between predators. However, little is known about how specific and effective induced defences are to different types of predators. We analysed the impact of both pursuing (fish, Gasterosteus aculeatus) and sit-and-wait (dragonfly, Aeshna cyanea) predators on tadpole (Rana dalmatina) morphology and performance (viz locomotive performance and growth rate). We also investigated the potential benefits of the predator-induced phenotype in the presence of fish predators. Both predators induced deeper tail fins in tadpoles exposed to threat of predation, and stickleback presence also induced longer tails and deeper tail muscles. Morphological and behavioural differences resulted in better escape ability of stickleback-induced tadpoles, leading to improved survival in the face of stickleback predation. These results clearly indicate that specific morphological responses to different types of predators have evolved in R. dalmatina. The specific morphologies suggest low correlations between the traits involved in the defence. Independence of traits allows prey species to fine-tune their response according to current predation risk, so that the benefit of the defence can be maximal.

  6. Haldane's rule in an avian system: using cline theory and divergence population genetics to test for differential introgression of mitochondrial, autosomal, and sex-linked loci across the Passerina bunting hybrid zone.

    PubMed

    Carling, Matthew D; Brumfield, Robb T

    2008-10-01

    Using cline fitting and divergence population genetics, we tested a prediction of Haldane's rule: autosomal alleles should introgress more than z-linked alleles or mitochondrial haplotypes across the Passerina amoena/Passerina cyanea (Aves: Cardinalidae) hybrid zone. We screened 222 individuals collected along a transect in the Great Plains of North America that spans the contact zone for mitochondrial (two genes), autosomal (four loci) and z-linked (two loci) markers. Maximum-likelihood cline widths estimated from the mitochondrial (223 km) and z-linked (309 km) datasets were significantly narrower on average than the autosomal cline widths (466 km). We also found that mean coalescent-based estimates of introgression were larger for the autosomal loci (0.63 genes/generation, scaled to the mutation rate mu) than for both the mitochondrial (0.27) and z-linked loci (0.59). These patterns are consistent with Haldane's rule, but the among-locus variation also suggests many independently segregating loci are required to investigate introgression patterns across the genome. These results provide the first comprehensive comparison of mitochondrial, sex-linked, and autosomal loci across an avian hybrid zone and add to the body of evidence suggesting that sex chromosomes play an important role in the formation and maintenance of reproductive isolation between closely related species.

  7. Magnetic information calibrates celestial cues during migration.

    PubMed

    Sandberg; Bäckman; Moore; Lõhmus

    2000-10-01

    Migratory birds use celestial and geomagnetic directional information to orient on their way between breeding and wintering areas. Cue-conflict experiments involving these two orientation cue systems have shown that directional information can be transferred from one system to the other by calibration. We designed experiments with four species of North American songbirds to: (1) examine whether these species calibrate orientation information from one system to the other; and (2) determine whether there are species-specific differences in calibration. Migratory orientation was recorded with two different techniques, cage tests and free-flight release tests, during autumn migration. Cage tests at dusk in the local geomagnetic field revealed species-specific differences: red-eyed vireo, Vireo olivaceus, and northern waterthrush, Seiurus noveboracensis, selected seasonally appropriate southerly directions whereas indigo bunting, Passerina cyanea, and grey catbird, Dumetella carolinensis, oriented towards the sunset direction. When tested in deflected magnetic fields, vireos and waterthrushes responded by shifting their orientation according to the deflection of the magnetic field, but buntings and catbirds failed to show any response to the treatment. In release tests, all four species showed that they had recalibrated their star compass on the basis of the magnetic field they had just experienced in the cage tests. Since release tests were done in the local geomagnetic field it seems clear that once the migratory direction is determined, most likely during the twilight period, the birds use their recalibrated star compass for orientation at departure. Copyright 2000 The Association for the Study of Animal Behaviour.

  8. Historical divergence and gene flow: coalescent analyses of mitochondrial, autosomal and sex-linked loci in Passerina buntings.

    PubMed

    Carling, Matthew D; Lovette, Irby J; Brumfield, Robb T

    2010-06-01

    Quantifying the role of gene flow during the divergence of closely related species is crucial to understanding the process of speciation. We collected DNA sequence data from 20 loci (one mitochondrial, 13 autosomal, and six sex-linked) for population samples of Lazuli Buntings (Passerina amoena) and Indigo Buntings (Passerina cyanea) (Aves: Cardinalidae) to test explicitly between a strict allopatric speciation model and a model in which divergence occurred despite postdivergence gene flow. Likelihood ratio tests of coalescent-based population genetic parameter estimates indicated a strong signal of postdivergence gene flow and a strict allopatric speciation model was rejected. Analyses of partitioned datasets (mitochondrial, autosomal, and sex-linked) suggest the overall gene flow patterns are driven primarily by autosomal gene flow, as there is no evidence of mitochondrial gene flow and we were unable to reject an allopatric speciation model for the sex-linked data. This pattern is consistent with either a parapatric divergence model or repeated periods of allopatry with gene flow occurring via secondary contact. These results are consistent with the low fitness of female avian hybrids under Haldane's rule and demonstrate that sex-linked loci likely are important in the initial generation of reproductive isolation, not just its maintenance.

  9. Automated recognition of bird song elements from continuous recordings using dynamic time warping and hidden Markov models: a comparative study.

    PubMed

    Kogan, J A; Margoliash, D

    1998-04-01

    The performance of two techniques is compared for automated recognition of bird song units from continuous recordings. The advantages and limitations of dynamic time warping (DTW) and hidden Markov models (HMMs) are evaluated on a large database of male songs of zebra finches (Taeniopygia guttata) and indigo buntings (Passerina cyanea), which have different types of vocalizations and have been recorded under different laboratory conditions. Depending on the quality of recordings and complexity of song, the DTW-based technique gives excellent to satisfactory performance. Under challenging conditions such as noisy recordings or presence of confusing short-duration calls, good performance of the DTW-based technique requires careful selection of templates that may demand expert knowledge. Because HMMs are trained, equivalent or even better performance of HMMs can be achieved based only on segmentation and labeling of constituent vocalizations, albeit with many more training examples than DTW templates. One weakness in HMM performance is the misclassification of short-duration vocalizations or song units with more variable structure (e.g., some calls, and syllables of plastic songs). To address these and other limitations, new approaches for analyzing bird vocalizations are discussed.

  10. Reef Fish Community Biomass and Trophic Structure Changes across Shallow to Upper-Mesophotic Reefs in the Mesoamerican Barrier Reef, Caribbean

    PubMed Central

    Gress, Erika; Wright, Georgina; Exton, Dan A.; Rogers, Alex D.

    2016-01-01

    Mesophotic coral ecosystems (MCEs; reefs 30-150m depth) are of increased research interest because of their potential role as depth refuges from many shallow reef threats. Yet few studies have identified patterns in fish species composition and trophic group structure between MCEs and their shallow counterparts. Here we explore reef fish species and biomass distributions across shallow to upper-MCE Caribbean reef gradients (5-40m) around Utila, Honduras, using a diver-operated stereo-video system. Broadly, we found reef fish species richness, abundance and biomass declining with depth. At the trophic group level we identified declines in herbivores (both total and relative community biomass) with depth, mostly driven by declines in parrotfish (Scaridae). Piscivores increased as a proportion of the community with increased depth while, in contrast to previous studies, we found no change in relative planktivorous reef fish biomass across the depth gradient. In addition, we also found evidence of ontogenetic migrations in the blue tang (Acanthurus coeruleus), striped parrotfish (Scarus iserti), blue chromis (Chromis cyanea), creole wrasse (Clepticus parrae), bluehead wrasse (Thalassoma bifasciatum) and yellowtail snapper (Ocyurus chrysurus), with a higher proportion of larger individuals at mesophotic and near-mesophotic depths than on shallow reefs. Our results highlight the importance of using biomass measures when considering fish community changes across depth gradients, with biomass generating different results to simple abundance counts. PMID:27332811

  11. Reef Fish Community Biomass and Trophic Structure Changes across Shallow to Upper-Mesophotic Reefs in the Mesoamerican Barrier Reef, Caribbean.

    PubMed

    Andradi-Brown, Dominic A; Gress, Erika; Wright, Georgina; Exton, Dan A; Rogers, Alex D

    2016-01-01

    Mesophotic coral ecosystems (MCEs; reefs 30-150m depth) are of increased research interest because of their potential role as depth refuges from many shallow reef threats. Yet few studies have identified patterns in fish species composition and trophic group structure between MCEs and their shallow counterparts. Here we explore reef fish species and biomass distributions across shallow to upper-MCE Caribbean reef gradients (5-40m) around Utila, Honduras, using a diver-operated stereo-video system. Broadly, we found reef fish species richness, abundance and biomass declining with depth. At the trophic group level we identified declines in herbivores (both total and relative community biomass) with depth, mostly driven by declines in parrotfish (Scaridae). Piscivores increased as a proportion of the community with increased depth while, in contrast to previous studies, we found no change in relative planktivorous reef fish biomass across the depth gradient. In addition, we also found evidence of ontogenetic migrations in the blue tang (Acanthurus coeruleus), striped parrotfish (Scarus iserti), blue chromis (Chromis cyanea), creole wrasse (Clepticus parrae), bluehead wrasse (Thalassoma bifasciatum) and yellowtail snapper (Ocyurus chrysurus), with a higher proportion of larger individuals at mesophotic and near-mesophotic depths than on shallow reefs. Our results highlight the importance of using biomass measures when considering fish community changes across depth gradients, with biomass generating different results to simple abundance counts.

  12. [Reef fishes community structure in 4 atolls of the San Andrés - Providencia Archipelago (Southwestern Caribbean)].

    PubMed

    Mejía, L S; Garzón-Ferreira, J

    2000-12-01

    In 1994 and 1995, 131 visual censuses of reef fishes were made using the stationary sampling method in Courtown, Albuquerque, Serrana and Roncador, four atolls of the Archipelago of San Andrés and Old Providence in the Southwestern Caribbean. Fish species and their abundances were recorded in four geomorphologic zones: lagoon, windward barrier reef, windward terrace and forereef terrace. A total of 98 species were censused; the most abundant were Chromis cyanea (14%), Clepticus parra (14%) and Stegastes partitus (10%). The most abundant families were Pomacentridae (37%), Labridae (28%) and Scaridae (10%). Analysis of similarities showed that differences between zones were greater than differences between atolls, but lagoon and forereef terrace were not significantly different. Cluster and ordination analysis confirmed these results; in addition, the ordination analysis placed the groups according to depth and wave-exposure gradients, suggesting that these two physical variables were responsibles for the clustering. Differences in equitability and species richness appear also due to these variables. Inverse analysis showed in each group few characteristic species, then the differences between zones were due specially to dominance of some species. The dominant trophic categories were planktivorous and herbivorous that were significantly different between zones. In shallow zones (shallow lagoonal patch reefs) and high wave-exposed zones (winward barrier reef) dominated herbivorous fishes, while in deeper zones (terraces and deep lagoonal patch reefs) planktivorous were more abundant.

  13. Combining Breeding Bird Survey and distance sampling to estimate density of migrant and breeding birds

    USGS Publications Warehouse

    Somershoe, S.G.; Twedt, D.J.; Reid, B.

    2006-01-01

    We combined Breeding Bird Survey point count protocol and distance sampling to survey spring migrant and breeding birds in Vicksburg National Military Park on 33 days between March and June of 2003 and 2004. For 26 of 106 detected species, we used program DISTANCE to estimate detection probabilities and densities from 660 3-min point counts in which detections were recorded within four distance annuli. For most species, estimates of detection probability, and thereby density estimates, were improved through incorporation of the proportion of forest cover at point count locations as a covariate. Our results suggest Breeding Bird Surveys would benefit from the use of distance sampling and a quantitative characterization of habitat at point count locations. During spring migration, we estimated that the most common migrant species accounted for a population of 5000-9000 birds in Vicksburg National Military Park (636 ha). Species with average populations of 300 individuals during migration were: Blue-gray Gnatcatcher (Polioptila caerulea), Cedar Waxwing (Bombycilla cedrorum), White-eyed Vireo (Vireo griseus), Indigo Bunting (Passerina cyanea), and Ruby-crowned Kinglet (Regulus calendula). Of 56 species that bred in Vicksburg National Military Park, we estimated that the most common 18 species accounted for 8150 individuals. The six most abundant breeding species, Blue-gray Gnatcatcher, White-eyed Vireo, Summer Tanager (Piranga rubra), Northern Cardinal (Cardinalis cardinalis), Carolina Wren (Thryothorus ludovicianus), and Brown-headed Cowbird (Molothrus ater), accounted for 5800 individuals.

  14. Building hierarchical models of avian distributions for the State of Georgia

    USGS Publications Warehouse

    Howell, J.E.; Peterson, J.T.; Conroy, M.J.

    2008-01-01

    To predict the distributions of breeding birds in the state of Georgia, USA, we built hierarchical models consisting of 4 levels of nested mapping units of decreasing area: 90,000 ha, 3,600 ha, 144 ha, and 5.76 ha. We used the Partners in Flight database of point counts to generate presence and absence data at locations across the state of Georgia for 9 avian species: Acadian flycatcher (Empidonax virescens), brownheaded nuthatch (Sitta pusilla), Carolina wren (Thryothorus ludovicianus), indigo bunting (Passerina cyanea), northern cardinal (Cardinalis cardinalis), prairie warbler (Dendroica discolor), yellow-billed cuckoo (Coccyxus americanus), white-eyed vireo (Vireo griseus), and wood thrush (Hylocichla mustelina). At each location, we estimated hierarchical-level-specific habitat measurements using the Georgia GAP Analysis18 class land cover and other Geographic Information System sources. We created candidate, species-specific occupancy models based on previously reported relationships, and fit these using Markov chain Monte Carlo procedures implemented in OpenBugs. We then created a confidence model set for each species based on Akaike's Information Criterion. We found hierarchical habitat relationships for all species. Three-fold cross-validation estimates of model accuracy indicated an average overall correct classification rate of 60.5%. Comparisons with existing Georgia GAP Analysis models indicated that our models were more accurate overall. Our results provide guidance to wildlife scientists and managers seeking predict avian occurrence as a function of local and landscape-level habitat attributes.

  15. Winter habitat occurrence patterns of temperate migrant birds in Belize

    USGS Publications Warehouse

    Dawson, D.K.; Robbins, C.S.; Sauer, J.R.

    1992-01-01

    We used mist nets and point counts to sample bird populations in 61 sites in Belize during January-March of 1987-1991. Sites were classified as forest, second growth, woody agricultural crops (citrus, mango, cacao, and cashew), or non-woody agricultural crops (rice and sugar cane). We evaluated patterns of occurence of wintering temperate migrant bird species in these habitats. Mist net captures of 22 of 31 migrant species differed significantly among habitats. Of these, 13 species were captured more frequently in the agricultural habitats. American Redstart (Setophaga ruticilla), Black-and-white Warbler (Mniotilta varia), and Magnolia Warbler (Dendroica magnolia) were among the species captured most frequently in woody agricultural habitats; captures of Common Yellowthroat (Geothlypis trichas), Indigo Bunting (Passerina cyanea), and Northern (lcterus galbula) and Orchard orioles (I. spur/anus) were highest in the non-woody agricultural sites. We relate these occurrence patterns to trends in breeding populations in North America. While count data provide a wide picture of winter habitat distribution of migrants, more intensive work is necessary to assess temporal and geographic variation of migrant bird use of agricultural habitats.

  16. Diversity in bee (Hymenoptera: Apoidea) and social wasp (Hymenoptera: Vespidae, Polistinae) community in "campos rupestres", Bahia, Brazil.

    PubMed

    da Silva-Pereira, Vivane; Santos, Gilberto M M

    2006-01-01

    Hymenoptera such as bees and social wasps are regular floral visitors in "campos rupestres" vegetation. A community of bees and social wasps was studied during floral visitation in an area of "campos rupestres", at Chapada Diamantina, BA, Brazil, from September 2001 to April 2002. The community was described in relation to diversity, evenness, and dominance rank, considering the individuals abundance (H' = 2.14/ J' = 0.55) and biomass (H' = 2.34/ J' = 0.60). Thirty nine bee (588 individuals/ 15.742 g) and 11 social wasp species (52 individuals/ 2.156 g) were collected, being the first report of social wasps for the Brazilian "campos rupestres". The main species regarding number of individuals were Trigona spinipes (Fabricius), Apis mellifera L., Frieseomelitta francoi (Moure), and Bombus brevivillus Franklin. About 48% of the species were represented by a single individual. There was an inversion in the dominance rank when the species biomass was considered. B. brevivillus, A. mellifera, T spinipes, and other species represented by 15 individuals or less, such as the social wasps Synoeca cyanea (Olivier), Polistes canadensis (L.) and Myschocyttarus drewseni (Saussure), and the bees Eufriesea nigrohirta (Friese), Xylocopa grisescens Lepeletier and Megachile (Pseudocentron) sp.l were the predominant species. The use of biomass in diversity analysis permitted to detect differences in the relative contribution of species in hierarchy dominance. The comparison between bee faunas from different areas indicates a large similarity of the sampled fauna in Palmeiras (Bahia State) with neighboring ecosystems, although with low values of similarity.

  17. Molecular phylogeny and historical biogeography of the neotropical swarm-founding social wasp genus Synoeca (Hymenoptera: Vespidae).

    PubMed

    Menezes, Rodolpho Santos Telles; Brady, Seán Gary; Carvalho, Antônio Freire; Del Lama, Marco Antonio; Costa, Marco Antônio

    2015-01-01

    The Neotropical Region harbors high biodiversity and many studies on mammals, reptiles, amphibians and avifauna have investigated the causes for this pattern. However, there is a paucity of such studies that focus on Neotropical insect groups. Synoeca de Saussure, 1852 is a Neotropical swarm-founding social wasp genus with five described species that is broadly and conspicuously distributed throughout the Neotropics. Here, we infer the phylogenetic relationships, diversification times, and historical biogeography of Synoeca species. We also investigate samples of the disjoint populations of S. septentrionalis that occur in both northwestern parts of South America through Central American and the Brazilian Atlantic rainforests. Our results showed that the interspecific relationships for Synoeca could be described as follows: (S. chalibea + S. virginea) + (S. cyanea + (S. septentrionalis/S. surinama)). Notably, samples of S. septentrionalis and S. surinama collected in the Atlantic Forest were interrelated and may be the result of incomplete lineage sorting and/or mitochondrial introgression among them. Our Bayesian divergence dating analysis revealed recent Plio-Pleistocene diversification in Synoeca. Moreover, our biogeographical analysis suggested an Amazonian origin of Synoeca, with three main dispersal events subsequently occurring during the Plio-Pleistocene.

  18. A computational study of the aerodynamic performance of a dragonfly wing section in gliding flight.

    PubMed

    Vargas, Abel; Mittal, Rajat; Dong, Haibo

    2008-06-01

    A comprehensive computational fluid-dynamics-based study of a pleated wing section based on the wing of Aeshna cyanea has been performed at ultra-low Reynolds numbers corresponding to the gliding flight of these dragonflies. In addition to the pleated wing, simulations have also been carried out for its smoothed counterpart (called the 'profiled' airfoil) and a flat plate in order to better understand the aerodynamic performance of the pleated wing. The simulations employ a sharp interface Cartesian-grid-based immersed boundary method, and a detailed critical assessment of the computed results was performed giving a high measure of confidence in the fidelity of the current simulations. The simulations demonstrate that the pleated airfoil produces comparable and at times higher lift than the profiled airfoil, with a drag comparable to that of its profiled counterpart. The higher lift and moderate drag associated with the pleated airfoil lead to an aerodynamic performance that is at least equivalent to and sometimes better than the profiled airfoil. The primary cause for the reduction in the overall drag of the pleated airfoil is the negative shear drag produced by the recirculation zones which form within the pleats. The current numerical simulations therefore clearly demonstrate that the pleated wing is an ingenious design of nature, which at times surpasses the aerodynamic performance of a more conventional smooth airfoil as well as that of a flat plate. For this reason, the pleated airfoil is an excellent candidate for a fixed wing micro-aerial vehicle design.

  19. Molecular cloning of kisspeptin receptor genes (gpr54-1 and gpr54-2) and their expression profiles in the brain of a tropical damselfish during different gonadal stages.

    PubMed

    Imamura, Satoshi; Hur, Sung-Pyo; Takeuchi, Yuki; Bouchekioua, Selma; Takemura, Akihiro

    2017-01-01

    The kisspeptin receptor (GPR54) mediates neuroendocrine control of kisspeptin in the brain and acts as a gateway for a pulsatile release of hypothalamic gonadotropin-releasing hormone. This study aimed to clone two GPR54 genes (gpr54-1 and gpr54-2) from the brain of the sapphire devil Chrysiptera cyanea, a tropical damselfish, and to study their involvement in reproduction. The partial sequences of the sapphire devil gpr54-1 cDNA (1059bp) and gpr54-2 cDNA (1098bp) each had an open reading frame encoding a protein of 353 and 366 amino acids, respectively, both of which had structural features of a G-protein-coupled receptor. The expression of gpr54-1 mRNA was observed in the diencephalon and telencephalon, and gpr54-2 mRNA was found in the optic tectum of sapphire devil. When gpr54-1 and gpr54-2 mRNA levels were examined in the brain of sapphire devil by real-time quantitative polymerase chain reaction (qPCR), they were found to increase during late vitellogenesis and post-spawning. Treatment of fish with estradiol-17β (Ε2) resulted in an increase in gpr54-1 and gpr54-2 expression in the brain of sapphire devil. Thus, kisspeptin receptors likely mediate the activity of kisspeptin in the brain and are involved in controlling reproductive events in a tropical damselfish.

  20. The effects of patch shape on indigo buntings. Evidence for an ecological trap

    SciTech Connect

    Weldon, Aimee J.; Haddad, Nick M.

    2005-01-01

    Weldon, Aimee, J., and Nick M. Haddad. 2005. The effect of patch shape on indigo buntings: Evidence for an ecological trap. Ecology 86(6):1422-1431. Abstract. Habitat loss and fragmentation have led to a widespread increase in the proportion of edge habitat in the landscape. Disturbance-dependent bird species are widely assumed to benefit from these edges. However, anthropogenic edges may concentrate nest predators while retaining habitat cues that birds use to select breeding habitat. This may lead birds to mistakenly select dangerous habitat a phenomenon known as an ecological trap. We experimentally demonstrated how habitat shape, and thus amount of edge, can adversely affect nest site selection and reproductive success of a disturbance-dependent bird species, the Indigo Bunting (Passerina cyanea). We did so within a landscape-scale experiment composed of equal-area habitat patches that differed in their amount of edge. Indigo Buntings preferentially selected edgy patches, which contained 50% more edge than more compact rectangular patches. Further, buntings fledged significantly fewer young per pair in edgy patches than in rectangular patches. These results provide the first experimental evidence that edges can function as ecological traps.