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Sample records for copepod eurytemora affinis

  1. Prymnesium parvum exotoxins affect the grazing and viability of the calanoid copepod Eurytemora affinis

    DEFF Research Database (Denmark)

    Sopanen, S.; Koski, Marja; Uronen, P.

    2008-01-01

    The calanoid copepod Eurytemora affinis from the northern Baltic Sea was exposed to cell-free filtrates of the toxic haptophyte Prymnesium parvum as well as to cell mixtures of P. parvum and Rhodomonas salina. To test the effects of P. parvum exudates and allelopathy on selective grazers, copepods...

  2. Behavioral responses of the estuarine calanoid copepod Eurytemora affinis to sub-lethal concentrations of waterborne pollutants

    Energy Technology Data Exchange (ETDEWEB)

    Michalec, François-Gaël [Université Lille Nord de France, F-59000 Lille (France); USTL, LOG, Station Marine de Wimereux, F-62930 Wimereux (France); CNRS, UMR 8187, F-62930 Wimereux (France); National Taiwan Ocean University, Institute of Marine Biology, Keelung, Taiwan, ROC (China); Holzner, Markus [Institute of Environmental Engineering, ETH Zürich (Switzerland); Menu, Dominique [Université Lille Nord de France, F-59000 Lille (France); USTL, LOG, Station Marine de Wimereux, F-62930 Wimereux (France); CNRS, UMR 8187, F-62930 Wimereux (France); Hwang, Jiang-Shiou [National Taiwan Ocean University, Institute of Marine Biology, Keelung, Taiwan, ROC (China); Souissi, Sami, E-mail: sami.souissi@univ-lille1.fr [Université Lille Nord de France, F-59000 Lille (France); USTL, LOG, Station Marine de Wimereux, F-62930 Wimereux (France); CNRS, UMR 8187, F-62930 Wimereux (France)

    2013-08-15

    Highlights: •We studied the effects of sub-lethal exposure to pollutants on Eurytemora affinis swimming behavior. •Nonylphenol, cadmium and polycyclic aromatic hydrocarbons caused hyperactivity. •Effects were observable within 30 min of exposure and persisted during a depuration period. •The response resembles an escape reaction allowing copepods to evade stressful conditions. -- Abstract: Estuarine waters contain a variety of chemicals which affect to various extents the behavior of aquatic organisms. Little is known, however, on the behavioral response of copepods. The present study shows the results of laboratory experiments investigating the immediate effects of sub-lethal concentrations of three commonly found contaminants on the three-dimensional swimming behavior of the estuarine calanoid copepod Eurytemora affinis. Nonylphenol at 2 μg L{sup −1}, cadmium at 45 ng L{sup −1} and a mixture of low to medium molecular weight polycyclic aromatic hydrocarbons at 40 ng L{sup −1} all affected the swimming behavior of E. affinis adults, increasing both swimming speed and activity. In most cases, effects were observable within 30 min of exposure and persisted or faded during a period of depuration in uncontaminated water of similar duration. In ovigerous females exposed to Cd and PAHs, effects appeared to be more pronounced during the depuration period, suggesting that carrying ovisacs may impair recovery. We quantified differences in the distribution of swimming speed values by considering the relative frequencies of periods of break, slow and fast swimming and we observed a trend toward faster movements in the presence of pollutants. The degree of trajectory complexity, estimated through their fractal dimension, was unaffected by pollutants. Since both narcotic and non-narcotic pollutants induced hyperactivity, our results suggest that changes in behavior after a short-term exposure may be independent of the general mode of action of the chemicals. The

  3. Physiological improvement in the copepod Eurytemora affinis through thermal and multi-generational selection

    DEFF Research Database (Denmark)

    Souissi, Anissa; Souissi, Sami; Hansen, Benni Winding

    2016-01-01

    . First two different copepod lines were obtained after long-term culture at constant cold (7°C) and warm (20°C) temperatures. Then both populations were transferred to a higher temperature of 24°C appropriate for aquaculture use and followed during five generations. During the first two generations (F1–F...

  4. Cryptic or pseudocryptic: can morphological methods inform copepod taxonomy? An analysis of publications and a case study of the Eurytemora affinis species complex.

    Science.gov (United States)

    Lajus, Dmitry; Sukhikh, Natalia; Alekseev, Victor

    2015-06-01

    Interest in cryptic species has increased significantly with current progress in genetic methods. The large number of cryptic species suggests that the resolution of traditional morphological techniques may be insufficient for taxonomical research. However, some species now considered to be cryptic may, in fact, be designated pseudocryptic after close morphological examination. Thus the "cryptic or pseudocryptic" dilemma speaks to the resolution of morphological analysis and its utility for identifying species. We address this dilemma first by systematically reviewing data published from 1980 to 2013 on cryptic species of Copepoda and then by performing an in-depth morphological study of the former Eurytemora affinis complex of cryptic species. Analyzing the published data showed that, in 5 of 24 revisions eligible for systematic review, cryptic species assignment was based solely on the genetic variation of forms without detailed morphological analysis to confirm the assignment. Therefore, some newly described cryptic species might be designated pseudocryptic under more detailed morphological analysis as happened with Eurytemora affinis complex. Recent genetic analyses of the complex found high levels of heterogeneity without morphological differences; it is argued to be cryptic. However, next detailed morphological analyses allowed to describe a number of valid species. Our study, using deep statistical analyses usually not applied for new species describing, of this species complex confirmed considerable differences between former cryptic species. In particular, fluctuating asymmetry (FA), the random variation of left and right structures, was significantly different between forms and provided independent information about their status. Our work showed that multivariate statistical approaches, such as principal component analysis, can be powerful techniques for the morphological discrimination of cryptic taxons. Despite increasing cryptic species designations

  5. Negligible effects of ocean acidification on Eurytemora affinis (Copepoda) offspring production

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    Almén, Anna-Karin; Vehmaa, Anu; Brutemark, Andreas; Bach, Lennart; Lischka, Silke; Stuhr, Annegret; Furuhagen, Sara; Paul, Allanah; Bermúdez, J. Rafael; Riebesell, Ulf; Engström-Öst, Jonna

    2016-02-01

    Ocean acidification is caused by increasing amounts of carbon dioxide dissolving in the oceans leading to lower seawater pH. We studied the effects of lowered pH on the calanoid copepod Eurytemora affinis during a mesocosm experiment conducted in a coastal area of the Baltic Sea. We measured copepod reproductive success as a function of pH, chlorophyll a concentration, diatom and dinoflagellate biomass, carbon to nitrogen (C : N) ratio of suspended particulate organic matter, as well as copepod fatty acid composition. The laboratory-based experiment was repeated four times during 4 consecutive weeks, with water and copepods sampled from pelagic mesocosms enriched with different CO2 concentrations. In addition, oxygen radical absorbance capacity (ORAC) of animals from the mesocosms was measured weekly to test whether the copepod's defence against oxidative stress was affected by pH. We found no effect of pH on offspring production. Phytoplankton biomass, as indicated by chlorophyll a concentration and dinoflagellate biomass, had a positive effect. The concentration of polyunsaturated fatty acids in the females was reflected in the eggs and had a positive effect on offspring production, whereas monounsaturated fatty acids of the females were reflected in their eggs but had no significant effect. ORAC was not affected by pH. From these experiments we conclude that E. affinis seems robust against direct exposure to ocean acidification on a physiological level, for the variables covered in the study. E. affinis may not have faced acute pH stress in the treatments as the species naturally face large pH fluctuations.

  6. Lipid nanocapsules for behavioural testing in aquatic toxicology: Time-response of Eurytemora affinis to environmental concentrations of PAHs and PCB.

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    Michalec, François-Gaël; Holzner, Markus; Souissi, Anissa; Stancheva, Stefka; Barras, Alexandre; Boukherroub, Rabah; Souissi, Sami

    2016-01-01

    The increasing interest for behavioural investigations in aquatic toxicology has heightened the need for developing tools that allow realistic exposure conditions and provide robust quantitative data. Calanoid copepods dominate the zooplankton community in marine and brackish environments. These small organisms have emerged as attractive models because of the sensitivity of their behaviour to important environmental parameters and the significance of self-induced motion in their ecology. Estuarine copepods are particularly relevant in this context because of their incessant exposure to high levels of pollution. We used lipid nanocapsules to deliver sub-lethal concentrations of PAHs (pyrene, phenanthrene and fluoranthene) and PCB 153 into the digestive track of males and females Eurytemora affinis. This novel approach enabled us to achieve both contact and trophic exposure without using phytoplankton, and to expose copepods to small hydrophobic molecules without using organic solvent. We reconstructed the motion of many copepods swimming simultaneously by means of three-dimensional particle tracking velocimetry. We quantified the combined effects of contact and trophic toxicity by comparing the kinematic and diffusive properties of their motion immediately and after 3h and 24h of exposure. Despite the lack of toxicity of their excipients, both empty and loaded capsules increased swimming activity and velocity immediately after exposure. Laser microscopy imaging shows adhesion of nanocapsules on the exoskeleton of the animals, suggesting contact toxicity. The behavioural response resembles an escape reaction allowing copepods to escape stressful conditions. The contact toxicity of empty capsules and pollutants appeared to be additive and nanocapsules loaded with PCB caused the greatest effects. We observed a progressive accumulation of capsules in the digestive track of the animals after 3h and 24h of exposure, which suggests an increasing contribution of systemic

  7. Predation vulnerability of planktonic copepods: consequences of predator foraging strategies and prey sensory abilities

    DEFF Research Database (Denmark)

    Viitasalo, M; Kiørboe, T; Flinkman, J.;

    1998-01-01

    We investigated the vulnerability of 2 copepod species (Eurytemora affinis and Temora longicornis) to predation by predators with different foraging modes, three-spined stickleback Gasterosteus aculeatus juveniles and mysid shrimps Neomysis integer. Copepods were videofilmed escaping from predators...... of the sticklebacks was higher than that of mysids. In the case of sticklebacks foraging on E. affinis, copepod reaction distance was significantly correlated with stickleback approaching speed; sticklebacks captured a copepod only if they were able to slowly approach to within a strike distance of...

  8. Biochemical composition of copepods for evaluation of feed quality in production of juvenile marine fish

    OpenAIRE

    van der Meeren, Terje; Olsen, Rolf Erik; Hamre, Kristin; Fyhn, Hans Jørgen

    2007-01-01

    To increase current knowledge on the nutritional value of natural prey organisms, the biochemical components of mainly three copepods (Acartia grani, Centropages hamatus, and Eurytemora affinis) from a marine pond system were analysed once a week from spring until late fall, over two years. The analysed components were total lipid, lipid class composition, total lipid fatty acid composition, free amino acids, total protein, protein-bound amino acids, pigment (astaxanthin and ß-carotene), and ...

  9. Vibrio elicits targeted transcriptional responses from copepod hosts.

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    Almada, Amalia A; Tarrant, Ann M

    2016-06-01

    Copepods are abundant crustaceans that harbor diverse bacterial communities, yet the nature of their interactions with microbiota are poorly understood. Here, we report that Vibrio elicits targeted transcriptional responses in the estuarine copepod Eurytemora affinis We pre-treated E. affinis with an antibiotic cocktail and exposed them to either a zooplankton specialist (Vibrio sp. F10 9ZB36) or a free-living species (Vibrio ordalii 12B09) for 24 h. We then identified via RNA-Seq a total of 78 genes that were differentially expressed following Vibrio exposure, including homologs of C-type lectins, chitin-binding proteins and saposins. The response differed between the two Vibrio treatments, with the greatest changes elicited upon inoculation with V. sp. F10 We suggest that these differentially regulated genes play important roles in cuticle integrity, the innate immune response, and general stress response, and that their expression may enable E. affinis to recognize and regulate symbiotic vibrios. We further report that V. sp. F10 culturability is specifically altered upon colonization of E. affinis These findings suggest that rather than acting as passive environmental vectors, copepods discriminately interact with vibrios, which may ultimately impact the abundance and activity of copepod-associated bacteria.

  10. Eurytemora carolleeae in the Laurentian Great Lakes revealed by phylogenetic and morphological analysis

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    Vasquez, Adrian A.; Hudson, Patrick L.; Fujimoto, Masanori; Keeler, Kevin M.; Armenio, Patricia M.; Ram, Jeffrey L.

    2016-01-01

    In the Laurentian Great Lakes, specimens of Eurytemora have been reported asEurytemora affinis since its invasion in the late 1950s. During an intensive collection of aquatic invertebrates for morphological and molecular identification in Western Lake Erie in 2012-2013, several specimens of Eurytemora were collected. Analysis of these specimens identified them as the recently described species Eurytemora carolleeaeAlekseev and Souissi 2011. This result led us to assess E. carolleeae’s identifying features, geographic distribution and historical presence in the Laurentian Great Lakes in view of its recent description in 2011. Cytochrome oxidase I (COI) DNA sequences ofEurytemora specimens were identified as closer (2 - 4% different) to recently describedE. carolleeae than to most E. affinis sequences (14% different). Eurytemora from other areas of the Great Lakes and from North American rivers as far west as South Dakota (Missouri River) and east to Delaware (Christina River) also keyed to E. carolleeae. Morphological analysis of archival specimens from 1962 and from all the Great Lakes was identified as E. carolleeae. Additionally, Eurytemora drawings in previous publications were reassessed to determine if the species was E. carolleeae and are reported here. Additional morphological characters that may distinguish North AmericanE. carolleeae from other taxa are also described. We conclude that E. carolleeae is the correct name for the species of Eurytemora that has inhabited the Great Lakes since its invasion, as established by both morphological and COI sequence comparisons to reference keys and sequence databases in present and archival specimens.

  11. Bloom-forming cyanobacteria support copepod reproduction and development in the Baltic Sea.

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    Hogfors, Hedvig; Motwani, Nisha H; Hajdu, Susanna; El-Shehawy, Rehab; Holmborn, Towe; Vehmaa, Anu; Engström-Öst, Jonna; Brutemark, Andreas; Gorokhova, Elena

    2014-01-01

    It is commonly accepted that summer cyanobacterial blooms cannot be efficiently utilized by grazers due to low nutritional quality and production of toxins; however the evidence for such effects in situ is often contradictory. Using field and experimental observations on Baltic copepods and bloom-forming diazotrophic filamentous cyanobacteria, we show that cyanobacteria may in fact support zooplankton production during summer. To highlight this side of zooplankton-cyanobacteria interactions, we conducted: (1) a field survey investigating linkages between cyanobacteria, reproduction and growth indices in the copepod Acartia tonsa; (2) an experiment testing relationships between ingestion of the cyanobacterium Nodularia spumigena (measured by molecular diet analysis) and organismal responses (oxidative balance, reproduction and development) in the copepod A. bifilosa; and (3) an analysis of long term (1999-2009) data testing relationships between cyanobacteria and growth indices in nauplii of the copepods, Acartia spp. and Eurytemora affinis, in a coastal area of the northern Baltic proper. In the field survey, N. spumigena had positive effects on copepod egg production and egg viability, effectively increasing their viable egg production. By contrast, Aphanizomenon sp. showed a negative relationship with egg viability yet no significant effect on the viable egg production. In the experiment, ingestion of N. spumigena mixed with green algae Brachiomonas submarina had significant positive effects on copepod oxidative balance, egg viability and development of early nauplial stages, whereas egg production was negatively affected. Finally, the long term data analysis identified cyanobacteria as a significant positive predictor for the nauplial growth in Acartia spp. and E. affinis. Taken together, these results suggest that bloom forming diazotrophic cyanobacteria contribute to feeding and reproduction of zooplankton during summer and create a favorable growth

  12. Short-term exposure to gold nanoparticle suspension impairs swimming behavior in a widespread calanoid copepod.

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    Michalec, François-Gaël; Holzner, Markus; Barras, Alexandre; Lacoste, Anne-Sophie; Brunet, Loïc; Lee, Jae-Seong; Slomianny, Christian; Boukherroub, Rabah; Souissi, Sami

    2017-09-01

    Calanoid copepods play an important role in the functioning of marine and brackish ecosystems. Information is scarce on the behavioral toxicity of engineered nanoparticles to these abundant planktonic organisms. We assessed the effects of short-term exposure to nonfunctionalized gold nanoparticles on the swimming behavior of the widespread estuarine copepod Eurytemora affinis. By means of three-dimensional particle tracking velocimetry, we reconstructed the trajectories of males, ovigerous and non-ovigerous females. We quantified changes in their swimming activity and in the kinematics and geometrical properties of their motion, three important descriptors of the motility patterns of zooplankters. In females, exposure to gold nanoparticles in suspension (11.4 μg L(-1)) for 30 min caused depressed activity and lower velocity and acceleration, whereas the same exposure caused minimal effects in males. This response differs clearly from the hyperactive behavior that is commonly observed in zooplankters exposed to pollutants, and from the generally lower sensitivity of female copepods to toxicants. Accumulation of gold nanoparticles on the external appendages was not observed, precluding mechanical effects. Only very few nanoparticles appeared sporadically in the inner part of the gut in some samples, either as aggregates or as isolated nanoparticles, which does not suggest systemic toxicity resulting from pronounced ingestion. Hence, the precise mechanisms underlying the behavioral toxicity observed here remain to be elucidated. These results demonstrate that gold nanoparticles can induce marked behavioral alterations at very low concentration and short exposure duration. They illustrate the applicability of swimming behavior as a suitable and sensitive endpoint for investigating the toxicity of nanomaterials present in estuarine and marine environments. Changes in swimming behavior may impair the ability of planktonic copepods to interact with their environment

  13. New records of the rare glacial relict Eurytemora lacustris (Poppe 1887 (Copepoda; Calanoida in atypical lake habitats of northern Germany

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    Peter KASPRZAK

    2011-02-01

    Full Text Available During monitoring investigations of lakes in Schleswig-Holstein (northern Germany in 2000 and 2008, the calanoid copepod Eurytemora lacustris (POPPE 1887 was found in three lakes of the Ratzeburger Lake complex: the Kleine Küchensee, the Große Küchensee and the Große Ratzeburger See. The species has a broad geographic distribution but has become rare and endangered by eutrophication and global change. The lakes are mesotrophic (Gr. Ratzeburger See and eutrophic (Kl. Küchensee, Gr. Küchensee with cool (1 mg O2 L-1. Food and physical conditions seem to be favourable enough to permit survival and reproduction of the species at least in spring. It remains unclear, however, whether the populations in the studied lakes are autochthonous. Eurytemora lacustris possibly invaded the lakes or was transported via a canal from the Schaalsee upstream, where a viable population exists.

  14. A simple device for culturing marine calanoid copepods and notes on the biology of

    NARCIS (Netherlands)

    Yassen, S.T.

    1973-01-01

    A simple device for culturing marine calanoid copepods is described. Calanus helgolandicus Pacificus, Acartia clausi Giesbrecht, Temora longicornis Muller, and Eurytemora hirundoides Nordquist, were reared in this device. The latter had been bred in the laboratory for

  15. Distinct Aeromonas Populations in Water Column and Associated with Copepods from Estuarine Environment (Seine, France

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    Gautier Chaix

    2017-07-01

    Full Text Available Aeromonas spp. are ubiquitous bacteria primarily recovered from aquatic ecosystems. They are found in fresh water as well as estuarine and marine waters, and in association with numerous autochthonous aquatic organisms in these environments. However, aeromonads are also etiologic agents of fish diseases and are now recognized as emerging pathogens in humans. The estuary is therefore a key environment, harboring autochthonous aeromonads, and aeromonads originating from humans and animals, mainly released by treated WWTP effluent or watershed run-off via tributaries. The present study compares the abundance and the diversity of Aeromonas populations. Over 2 years of monitoring (eight campaigns from February 2013 to November 2015, the occurrence of Aeromonas was investigated within the water column (water and fluid mud and in association with copepods. Moreover, the diversity of Aeromonas populations was ascertained by analyzing gyrB and radA sequences, and the antibiotic-resistance phenotypes were determined using the disk diffusion method. This study shows, for the first time, the presence of Aeromonas spp. in water (1.1 × 102 to 1.2 ± 0.3 × 103 CFU.100 mL-1, fluid mud (2.6 ± 2.6 × 102 to 9.8 ± 0.9 × 103 CFU.g-1 and in association with living copepods (1.9 ± 0.7 × 102 to >1.1 × 104 CFU.g-1 in the Seine estuary. Moreover, the diversity study, conducted on 36 strains isolated from the water column and 47 strains isolated from copepods, indicates distinct populations within these two compartments. Strains distributed in five clusters corresponding to A. bestiarum (n = 6; 5.45%, A. encheleia (n = 1; 0.91%, A. media (n = 22; 20.0%, A. rivipollensis (n = 34; 30.91% and A. salmonicida (n = 47; 42.73%. A. salmonicida is the most abundant species associated with Eurytemora affinis (n = 35; 74.47%. In contrast, A. salmonicida accounts for only 30.56% (n = 11 of isolates in the water column. This study shows the coexistence of distinct populations

  16. Distinct Aeromonas Populations in Water Column and Associated with Copepods from Estuarine Environment (Seine, France)

    Science.gov (United States)

    Chaix, Gautier; Roger, Frédéric; Berthe, Thierry; Lamy, Brigitte; Jumas-Bilak, Estelle; Lafite, Robert; Forget-Leray, Joëlle; Petit, Fabienne

    2017-01-01

    Aeromonas spp. are ubiquitous bacteria primarily recovered from aquatic ecosystems. They are found in fresh water as well as estuarine and marine waters, and in association with numerous autochthonous aquatic organisms in these environments. However, aeromonads are also etiologic agents of fish diseases and are now recognized as emerging pathogens in humans. The estuary is therefore a key environment, harboring autochthonous aeromonads, and aeromonads originating from humans and animals, mainly released by treated WWTP effluent or watershed run-off via tributaries. The present study compares the abundance and the diversity of Aeromonas populations. Over 2 years of monitoring (eight campaigns from February 2013 to November 2015), the occurrence of Aeromonas was investigated within the water column (water and fluid mud) and in association with copepods. Moreover, the diversity of Aeromonas populations was ascertained by analyzing gyrB and radA sequences, and the antibiotic-resistance phenotypes were determined using the disk diffusion method. This study shows, for the first time, the presence of Aeromonas spp. in water (1.1 × 102 to 1.2 ± 0.3 × 103 CFU.100 mL-1), fluid mud (2.6 ± 2.6 × 102 to 9.8 ± 0.9 × 103 CFU.g-1) and in association with living copepods (1.9 ± 0.7 × 102 to >1.1 × 104 CFU.g-1) in the Seine estuary. Moreover, the diversity study, conducted on 36 strains isolated from the water column and 47 strains isolated from copepods, indicates distinct populations within these two compartments. Strains distributed in five clusters corresponding to A. bestiarum (n = 6; 5.45%), A. encheleia (n = 1; 0.91%), A. media (n = 22; 20.0%), A. rivipollensis (n = 34; 30.91%) and A. salmonicida (n = 47; 42.73%). A. salmonicida is the most abundant species associated with Eurytemora affinis (n = 35; 74.47%). In contrast, A. salmonicida accounts for only 30.56% (n = 11) of isolates in the water column. This study shows the coexistence of distinct populations of

  17. Ocean acidification impact on copepod swimming and mating behavior: consequences for population dynamics

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    Seuront, L.

    2010-12-01

    calanoid copepods Eurytemora affinis and Temora longicornis. Behavioral and mating experiments were conducted under conditions of control seawater (pH = 8.1) and conditions of ocean pH expected to occur circa 2100 (i.e. pH = 7.8 to 7.6) because of present and future CO2 emissions under the SRES A2 scenario. Our results indicate that ocean acidification modifies E. affinis and T. longicornis swimming and mating behaviors, and mating success. Specifically, ocean acidification significantly (i) modifies the stochastic properties of successive displacements, leading to decrease mate encounter rates when copepods cannot rely on female pheromone plumes (i.e. under turbulent conditions) and (ii) decreases the ability of males to detect females pheromone trails, to accurately follow trails and to successfully track a female. This led to a significant decrease in contact and capture rates from control to acidified seawater. These results indicate that ocean acification decreases the ability of male copepods to detect, track and capture a female, hence suggest an overall impact on population fitness and dynamics.

  18. A new subspecies of Nitokra affinis Gurney, 1927 (Copepoda, Harpacticoida) from the Caribbean coast of Colombia

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    Fuentes-Reinés, Juan M.; Suárez-Morales, Eduardo

    2014-01-01

    Abstract Plankton samples from Laguna Navio Quebrado, La Guajira, northern Colombia, yielded male and female specimens of an harpacticoid copepod that was first identified as the widely distributed species Nitokra affinis Gurney, 1927 for which at least four subspecies have been described from different geographic areas. A more detailed examination of the Colombian specimens revealed that it differs from the other morphs so far considered as subspecies. The Colombian specimens differ from the other four known subspecies in the following aspects: (1) rostrum with long projection, (2) relatively long exopod of P1, almost as long as first endopodal segment, (3) endopodal and exopodal rami of P2 equally long, (4) a reduced number of endopodal setal elements of the male P5. It also differs from N. a. californica Lang in details of the ornamentation of the urosomites. Descriptions and illustrations of this new subspecies, the first one described from the Neotropical region, are presented together with a key to the five known subspecies of Nitokra affinis. As in many other cases of presumedly widespread species of harpacticoids, it is possible that N. affinis represents a species complex with more restricted distributional patterns, a notion that certainly deserves further study. PMID:24574850

  19. Mesozooplankton affinities in a recovering freshwater estuary

    NARCIS (Netherlands)

    Chambord, S.; Maris, T.; Colas, F.; van Engeland, T.; Sossou, A.-C.; Azémar, F.; Le Coz, M.; Cox, T.; Buisson, L.; Souissi, S.; Meire, P.; Tackx, M.

    2016-01-01

    Water quality of the Scheldt estuary (Belgium/The Netherlands) has considerably improved in recent years, especially in the upstream, freshwater reaches. Within the zooplankton community, the copepod Eurytemora affinis, typically abundant in brackish water and quasi-absent from freshwater

  20. Mesopelagic fishes of the Arabian Sea: distribution, abundance and diet of Chauliodus pammelas, Chauliodus sloani, Stomias affinis, and Stomias nebulosus

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    Butler, Mari; Bollens, Stephen M.; Burkhalter, Brenda; Madin, Laurence P.; Horgan, Erich

    Four species of predatory fishes - Chauliodus pammelas, Chauliodus sloani, Stomias affinis and Stomias nebulosus - were collected on two cruises to the Arabian Sea during 1995. We present data on the abundances, horizontal and vertical distributions, and diet of these fishes. We also discuss briefly the importance of the oxygen minimum zone and predation on myctophid fishes to the ecology of these mesopelagic predators. Chauliodus pammelas and C. sloani appear to have only partially overlapping horizontal distributions in the Arabian Sea, with C. pammelas more common to the north and C. sloani more common to the south. Our data support previous results suggesting that diel vertical migration is the norm for these species, with smaller individuals usually nearer to the surface and larger individuals tending to stay deeper. In contrast to Chauliodus, Stomias affinis and S. nebulosus appear to have largely overlapping horizontal distributions in the Arabian Sea. However, they may have slightly different vertical distributions, with S. affinis living slightly shallower (especially at night) than S. nebulosus. All four species spend most of their time in the oxygen minimum zone, entering the surface oxygenated waters (100-150 m) only at night (if at all). The diets of C. pammelas, C. sloani, and S. affinis consisted mainly of lanternfishes, Myctophidae, and other fishes. In contrast, S. nebulosus, the smaller of the two Stomias species, ate mostly copepods and other crustaceans. This differential feeding may allow the two Stomias species to co-occur. Three of these four stomiids appear to play an important role in predation on myctophid fish populations in the Arabian Sea.

  1. The chemical ecology of copepods

    DEFF Research Database (Denmark)

    Heuschele, Jan; Selander, Erik

    2014-01-01

    for the functioning of the marine food web, much is still unknown. We synthesize current knowledge about chemical ecology of copepods including foraging, survival and reproduction. We also compile information on the sensory apparatus and new analytical approaches that may facilitate the identification of signal...... molecules. The review illustrates the importance of chemical interactions in many aspects of copepod ecology and identifies gaps in our knowledge, such as the lack of identified infochemicals and electrophysiological studies to confirm the function of sensory structures. We suggest approaches...

  2. The chemical ecology of copepods

    DEFF Research Database (Denmark)

    Heuschele, Jan; Selander, Erik

    2014-01-01

    for the functioning of the marine food web, much is still unknown. We synthesize current knowledge about chemical ecology of copepods including foraging, survival and reproduction. We also compile information on the sensory apparatus and new analytical approaches that may facilitate the identification of signal...... molecules. The review illustrates the importance of chemical interactions in many aspects of copepod ecology and identifies gaps in our knowledge, such as the lack of identified infochemicals and electrophysiological studies to confirm the function of sensory structures. We suggest approaches...

  3. Mysoria affinis (Herrich-Schäffer: morphological variation and synonymy (Lepidoptera, Hesperiidae, Pyrrhopyginae

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    Andrew D. Warren

    2004-06-01

    Full Text Available Mysoria wilsoni H.A. Freeman, 1969, is established as a new junior synonym of Mysoria affinis (Herrich-Schäffer, 1869. A lectotype for Pyrrhopyga [sic] affinis Herrich-Schäffer, 1869 is designated.Mysoria wilsoni H.A. Freeman, 1969 é estabelecido como um novo sinônimo junior de Mysoria affinis (Herrich-Schäffer, 1869. Um lectótipo para Pyrrhopyga [sic] affinis Herrich-Schäffer, 1869 é designado.

  4. Molecular differentiation within and among island populations of the endemic plant Scalesia affinis (Asteraceae) from the Galápagos Islands

    DEFF Research Database (Denmark)

    Nielsen, Lene Rostgaard

    2004-01-01

    Scalesia affinis, Galápagos, AFLP, endangered populations, discriminant analysis, chloroplast microsatellites......Scalesia affinis, Galápagos, AFLP, endangered populations, discriminant analysis, chloroplast microsatellites...

  5. What makes pelagic copepods so successful?

    DEFF Research Database (Denmark)

    Kiørboe, Thomas

    2011-01-01

    Three features that are unique or almost unique to pelagic copepods among zooplankton may account for their numerical dominance in the pelagic realm of the oceans: (i) the torpedo-shaped body, the sensory armed antennules and the ‘gearing’ of the muscle motor make pelagic copepods very efficient...

  6. Regional ecological risk assessment for the introduction of Gambusia affinis (western mosquitofish) into Montana watersheds

    Science.gov (United States)

    Jerome J. Schleier; Sing Sharlene E.; Robert K. D. Peterson

    2008-01-01

    Qualitative risk assessment methodologies were used to assess the risk of establishment and consequent impacts on native minnows and species of concern (SOC) associated with the intentional or unintentional introduction of the mosquito biological control agent, Gambusia affinis, to various Montana watersheds. Gambusia affinis...

  7. Taxonomic and ecological notes on Buenia affinis Iljin 1930 (Pisces: Gobiidae)

    Energy Technology Data Exchange (ETDEWEB)

    Costa, F.; Giacobbe, S.; Salpietro, L. [S. Agata, Messina, Univ. (Italy). Facolta` di Scienze. Dipt. di Biologia Animale ed Ecologia Marina

    1996-12-31

    Taxonomic and ecological notes on Buenia affinis Iljin 1930 (Pisces: Gobiidae). A population of the rare Teleost Buenia affinis Iljin 1930 has been sampled in a brackish pool along the Sicilian Tyrrhenic coastline. A description of the taxonomic features as well as first observations on the ecology of the species are given in detail.

  8. Coccidioidomycosis in a Sonoran gopher snake, Pituophis melanoleucus affinis.

    Science.gov (United States)

    Timm, K I; Sonn, R J; Hultgren, B D

    1988-04-01

    Coccidioides immitis was isolated from lesions in the lung of a Sonoran Gopher snake, Pituophis melanoleucus affinis. A lactophenol cotton blue mount of a fungal colony grown on Sabouraud's agar revealed coarse, branching, septate hyphae with alternating thick-walled arthroconidia. Histologically, the lung lesions contained spherical, non-budding, double-walled spherules in various stages of maturity. Some spherules contained endospores. Spherules were also present in granulomas associated with the thyroid and pancreas. A diagnosis was made of disseminated coccidioidomycosis, a condition not previously reported in a reptile.

  9. Spliced leader RNA trans-splicing discovered in copepods

    Science.gov (United States)

    Yang, Feifei; Xu, Donghui; Zhuang, Yunyun; Yi, Xiaoyan; Huang, Yousong; Chen, Hongju; Lin, Senjie; Campbell, David A.; Sturm, Nancy R.; Liu, Guangxing; Zhang, Huan

    2015-12-01

    Copepods are one of the most abundant metazoans in the marine ecosystem, constituting a critical link in aquatic food webs and contributing significantly to the global carbon budget, yet molecular mechanisms of their gene expression are not well understood. Here we report the detection of spliced leader (SL) trans-splicing in calanoid copepods. We have examined nine species of wild-caught copepods from Jiaozhou Bay, China that represent the major families of the calanoids. All these species contained a common 46-nt SL (CopepodSL). We further determined the size of CopepodSL precursor RNA (slRNA; 108-158 nt) through genomic analysis and 3‧-RACE technique, which was confirmed by RNA blot analysis. Structure modeling showed that the copepod slRNA folded into typical slRNA secondary structures. Using a CopepodSL-based primer set, we selectively enriched and sequenced copepod full-length cDNAs, which led to the characterization of copepod transcripts and the cataloging of the complete set of 79 eukaryotic cytoplasmic ribosomal proteins (cRPs) for a single copepod species. We uncovered the SL trans-splicing in copepod natural populations, and demonstrated that CopepodSL was a sensitive and specific tool for copepod transcriptomic studies at both the individual and population levels and that it would be useful for metatranscriptomic analysis of copepods.

  10. Optimal mate choice patterns in pelagic copepods

    DEFF Research Database (Denmark)

    Heuschele, Jan; Eliassen, Sigrun; Kiørboe, Thomas

    2013-01-01

    The importance of sexual selection for the evolution, dynamics and adaptation of organisms is well known for many species. However, the topic is rarely studied in marine plankton, the basis of the marine food web. Copepods show behaviors that suggest the existence of sexually selected traits......, and recent laboratory experiments identified some selected morphological traits. Here, we use a ‘life history-based’ model of sex roles to determine the optimal choosiness behavior of male and female copepods for important copepod traits. Copepod females are predicted to be choosy at population densities...... typically occurring during the main breeding season, whereas males are not. The main drivers of this pattern are population density and the difference in non-receptive periods between males and females. This suggests that male reproductive traits have evolved mainly due to mate competition. The model can...

  11. Degradation of copepod fecal pellets

    DEFF Research Database (Denmark)

    Poulsen, Louise K.; Iversen, Morten

    2008-01-01

    Copepod fecal pellets are often degraded at high rates within the upper part of the water column. However, the identity of the degraders and the processes governing the degradation remain unresolved. To identify the pellet degraders we collected water from Oresund (Denmark) approximately every...... second month from July 2004 to July 2005. These water samples were divided into 5 fractions (pellet degradation rate and species composition of the plankton from triplicate incubations of each fraction and a known, added...... amount of fecal pellets. The total degradation rate of pellets by the natural plankton community of Oresund followed the phytoplankton biomass, with maximum degradation rate during the spring bloom (2.5 +/- 0.49 d(-1)) and minimum (0.52 +/- 0.14 d(-1)) during late winter. Total pellet removal rate ranged...

  12. Observing copepods through a genomic lens

    Directory of Open Access Journals (Sweden)

    Johnson Stewart C

    2011-09-01

    Full Text Available Abstract Background Copepods outnumber every other multicellular animal group. They are critical components of the world's freshwater and marine ecosystems, sensitive indicators of local and global climate change, key ecosystem service providers, parasites and predators of economically important aquatic animals and potential vectors of waterborne disease. Copepods sustain the world fisheries that nourish and support human populations. Although genomic tools have transformed many areas of biological and biomedical research, their power to elucidate aspects of the biology, behavior and ecology of copepods has only recently begun to be exploited. Discussion The extraordinary biological and ecological diversity of the subclass Copepoda provides both unique advantages for addressing key problems in aquatic systems and formidable challenges for developing a focused genomics strategy. This article provides an overview of genomic studies of copepods and discusses strategies for using genomics tools to address key questions at levels extending from individuals to ecosystems. Genomics can, for instance, help to decipher patterns of genome evolution such as those that occur during transitions from free living to symbiotic and parasitic lifestyles and can assist in the identification of genetic mechanisms and accompanying physiological changes associated with adaptation to new or physiologically challenging environments. The adaptive significance of the diversity in genome size and unique mechanisms of genome reorganization during development could similarly be explored. Genome-wide and EST studies of parasitic copepods of salmon and large EST studies of selected free-living copepods have demonstrated the potential utility of modern genomics approaches for the study of copepods and have generated resources such as EST libraries, shotgun genome sequences, BAC libraries, genome maps and inbred lines that will be invaluable in assisting further efforts to

  13. Intermittent swarming of copepods in Versova mangrove, Mumbai

    Digital Repository Service at National Institute of Oceanography (India)

    Stephen, R.; Jayalakshmy, K.V.; Nair, V.R.

    suggested as an adaptive advantage for feeding, propagation, protection and dispersal by currents. Copepod swarms are usually monospecific and are composed of adult and late stage copepodites. While studying the copepod composition of Versova mangrove...

  14. New Records of Ixodes affinis (Acari: Ixodidae) Parasitizing Avian Hosts in Southeastern Virginia.

    Science.gov (United States)

    Heller, Erin L; Wright, Chelsea L; Nadolny, Robyn M; Hynes, Wayne L; Gaff, Holly D; Walters, Eric L

    2016-03-01

    Ixodes affinis Neumann (Acari: Ixodidae) is a hard-bodied tick species distributed throughout much of the southeastern United States. Although I. affinis does not parasitize humans, it is a competent vector of Borrelia burgdorferi sensu stricto, the causative-agent of Lyme disease, and thus contributes to the enzootic maintenance of this pathogen. This study presents evidence of I. affinis parasitizing five new host passerine species. During 2012-2014, 1,888 birds were captured and examined for ticks, and 18 immature I. affinis were collected from 12 birds-six Carolina Wrens (Thyrothorus ludovicianus); two Brown Thrashers (Toxostoma rufum); and one American Robin (Turdus migratorius), Eastern Towhee (Pipilo erythrophthalmus), Northern Cardinal (Cardinalis cardinalis), and White-throated Sparrow (Zonotrichia albicollis). Of 15 larvae and 3 nymphs collected, one nymph tested positive for B. burgdorferi DNA. I. affinis was found co-feeding on birds with immature Amblyomma americanum (L.), Ixodes brunneus Koch, Ixodes dentatus Marx, Ixodes scapularis Say, and Haemaphysalis leporispalustris Packard. The results of this research provide a better understanding of I. affinis hosts and identify avian taxa that may play a role in the maintenance and dispersal of this tick species.

  15. Copepods and fishes in the Brazilian Amazon

    Science.gov (United States)

    Thatcher, Vernon E.

    1998-06-01

    The Amazon basin comprises the largest river ecosystem in the world (7 million km 2) with annual high and low water peaks and a constant temperature near 29°C. Some 2000 fish species and 40 species of free-living copepods are known to occur in Amazonia. The free-living forms serve as food for most larval fishes and some adults, but they also transmit several parasites including representatives of the nematode family Camallanidae. About three dozen species of parasitic copepods have been described from the Brazilian Amazon. Females of Amazonian parasitic copepods are found on skin, gill filaments, gill rakers or within the nasal fossae. Parasitic copepods are found on fishes that are from a few millimeters long up to those over 2 m in length and they are usually quite host specific. All have body pigmentation in different patterns and colors (frequently blues, such as cerulean, cobalt, spectrum, smalt or campanula). It is suggested that the coloration serves to attract specific host fish. Copepods have evolved adaptations for attachment and feeding, especially in the second antennae and endopods. Examples of progenesis, phoresis and commensalism are shown. Some species produce pathology such as a tourniquet effect, hyperplasia, blood loss and anemia, and can kill fishes by limiting their respiration.

  16. Prey detection in a cruising copepod

    DEFF Research Database (Denmark)

    Kjellerup, Sanne; Kiørboe, Thomas

    2012-01-01

    Small cruising zooplankton depend on remote prey detection and active prey capture for efficient feeding. Direct, passive interception of prey is inherently very inefficient at low Reynolds numbers because the viscous boundary layer surrounding the approaching predator will push away potential prey....... Yet, direct interception has been proposed to explain how rapidly cruising, blind copepods feed on non-motile phytoplankton prey. Here, we demonstrate a novel mechanism for prey detection in a cruising copepod, and describe how motile and non-motile prey are discovered by hydromechanical and tactile...

  17. Prey detection in a cruising copepod

    DEFF Research Database (Denmark)

    Kjellerup, Sanne; Kiørboe, Thomas

    2012-01-01

    Small cruising zooplankton depend on remote prey detection and active prey capture for efficient feeding. Direct, passive interception of prey is inherently very inefficient at low Reynolds numbers because the viscous boundary layer surrounding the approaching predator will push away potential prey....... Yet, direct interception has been proposed to explain how rapidly cruising, blind copepods feed on non-motile phytoplankton prey. Here, we demonstrate a novel mechanism for prey detection in a cruising copepod, and describe how motile and non-motile prey are discovered by hydromechanical and tactile...

  18. A plea for the use of copepods in freshwater ecotoxicology

    DEFF Research Database (Denmark)

    Kulkarni, Devdutt; Gergs, André; Hommen, Udo

    2013-01-01

    . However, very little is known about the ecotoxicology of freshwater copepods. To enable a more realistic risk higher tier environmental risk assessment, we recommend considering freshwater copepods as part of the hazard assessment process. This could include the establishment of laboratory experiments...... consequences concerning the vulnerability of such species to exposure with contaminants. We aimed to highlight the importance of copepods in ecology and to underline the need to include freshwater copepods in ecotoxicology. We carried out a literature search on copepods and Daphnia in ecology and ecotoxicology...

  19. A plea for the use of copepods in freshwater ecotoxicology.

    Science.gov (United States)

    Kulkarni, Devdutt; Gergs, André; Hommen, Udo; Ratte, Hans Toni; Preuss, Thomas G

    2013-01-01

    Standard species used in ecological risk assessment are chosen based on their sensitivity to various toxicants and the ease of rearing them for laboratory experiments. However, this mostly overlooks the fact that species in the field that may employ variable life-history strategies, which may have consequences concerning the vulnerability of such species to exposure with contaminants. We aimed to highlight the importance of copepods in ecology and to underline the need to include freshwater copepods in ecotoxicology. We carried out a literature search on copepods and Daphnia in ecology and ecotoxicology to compare the recognition given to these two taxa in these respective fields. We also conducted a detailed analysis of the literature on copepods and their current role in ecotoxicology to characterize the scale and depth of the studies and the ecotoxicological information therein. The literature on the ecology of copepods outweighed that in ecotoxicology when compared with daphnids. Copepods, like other zooplankton, were found to be sensitive to toxicants and important organisms in aquatic ecosystems. The few studies that were conducted on the ecotoxicology of copepods mainly focused on marine copepods. However, very little is known about the ecotoxicology of freshwater copepods. To enable a more realistic risk higher tier environmental risk assessment, we recommend considering freshwater copepods as part of the hazard assessment process. This could include the establishment of laboratory experiments to analyse the effects of toxicants on copepods and the development of individual-based models to extrapolate effects across species and scenarios.

  20. Response of mosquitofish (Gambusia affinis) populations to seasonally unpredictable perturbations

    Energy Technology Data Exchange (ETDEWEB)

    Horn, M.J.; Stewart, A.J.

    1990-07-01

    Many questions remain unresolved about the linkages between life history attributes of fishes and the tactics that these organisms employ in response to environmental uncertainty. Such questions include (1). If a perturbation affects the entire ecosystem, what are the consequences for a given population of fish (2) What tactics can a fish employ to increase its chances of leaving offspring (3) Do fish respond differently to such perturbations depending on the season (4) How do these changes relate to the overall resilience of the population The research reported here was designed to address such questions. Mosquito fish (Gambusia affinis) populations in thirteen experimental ponds at Oak Ridge National Laboratory were sampled ten times between June 1988, and July 1989 in response to a series of chemical disturbances. During each sampling period the population size and total biomass of Gambusia in each pond was estimated using photographs and a length weight regression. Size-frequency histograms were used to examine seasonal and dose-related changes in population structure. Lipid content and reproductive allotment were measured for a series of fish from each pond on all dates to explore the energy allocation patterns at the individual. 106 refs., 38 figs., 16 tabs.

  1. Colloquium on diatom-copepod interactions

    DEFF Research Database (Denmark)

    Paffenhofer, G.A.; Ianora, A.; Miralto, A.;

    2005-01-01

    From 3 to 6 November 2002, a colloquium was convened at the Benthos Laboratory of the Stazione Zoologica Anton Dohrn on Ischia, Italy, with the goal of evaluating the present status of the effects of diatoms on their main consumers, planktonic copepods, and to develop future research strategies...

  2. The microbiome of North Sea copepods

    Science.gov (United States)

    Gerdts, G.; Brandt, P.; Kreisel, K.; Boersma, M.; Schoo, K. L.; Wichels, A.

    2013-12-01

    Copepods can be associated with different kinds and different numbers of bacteria. This was already shown in the past with culture-dependent microbial methods or microscopy and more recently by using molecular tools. In our present study, we investigated the bacterial community of four frequently occurring copepod species, Acartia sp., Temora longicornis, Centropages sp. and Calanus helgolandicus from Helgoland Roads (North Sea) over a period of 2 years using DGGE (denaturing gradient gel electrophoresis) and subsequent sequencing of 16S-rDNA fragments. To complement the PCR-DGGE analyses, clone libraries of copepod samples from June 2007 to 208 were generated. Based on the DGGE banding patterns of the two years survey, we found no significant differences between the communities of distinct copepod species, nor did we find any seasonality. Overall, we identified 67 phylotypes (>97 % similarity) falling into the bacterial phyla of Actinobacteria, Bacteroidetes, Firmicutes and Proteobacteria. The most abundant phylotypes were affiliated to the Alphaproteobacteria. In comparison with PCR-DGGE and clone libraries, phylotypes of the Gammaproteobacteria dominated the clone libraries, whereas Alphaproteobacteria were most abundant in the PCR-DGGE analyses.

  3. A trait database for marine copepods

    DEFF Research Database (Denmark)

    Brun, Philipp Georg; Payne, Mark; Kiørboe, Thomas

    2017-01-01

    The trait-based approach is gaining increasing popularity in marine plankton ecology but the field urgently needs more and easier accessible trait data to advance.We compiled trait information on marine pelagic copepods, a major group of zooplankton, from the published literature and from experts...

  4. Algal toxins alter copepod feeding behavior.

    Directory of Open Access Journals (Sweden)

    Jiarong Hong

    Full Text Available Using digital holographic cinematography, we quantify and compare the feeding behavior of free-swimming copepods, Acartia tonsa, on nutritional prey (Storeatula major to that occurring during exposure to toxic and non-toxic strains of Karenia brevis and Karlodinium veneficum. These two harmful algal species produce polyketide toxins with different modes of action and potency. We distinguish between two different beating modes of the copepod's feeding appendages-a "sampling beating" that has short durations (<100 ms and involves little fluid entrainment and a longer duration "grazing beating" that persists up to 1200 ms and generates feeding currents. The durations of both beating modes have log-normal distributions. Without prey, A. tonsa only samples the environment at low frequency. Upon introduction of non-toxic food, it increases its sampling time moderately and the grazing period substantially. On mono algal diets for either of the toxic dinoflagellates, sampling time fraction is high but the grazing is very limited. A. tonsa demonstrates aversion to both toxic algal species. In mixtures of S. major and the neurotoxin producing K. brevis, sampling and grazing diminish rapidly, presumably due to neurological effects of consuming brevetoxins while trying to feed on S. major. In contrast, on mixtures of cytotoxin producing K. veneficum, both behavioral modes persist, indicating that intake of karlotoxins does not immediately inhibit the copepod's grazing behavior. These findings add critical insight into how these algal toxins may influence the copepod's feeding behavior, and suggest how some harmful algal species may alter top-down control exerted by grazers like copepods.

  5. [Effects of starvation on the consumption of energy sources and swimming performance in juvenile Gambusia affinis and Tanichthys albonubes].

    Science.gov (United States)

    Li, Jiang-tao; Lin, Xiao-tao; Zhou, Chen-hui; Zeng, Peng; Xu, Zhong-neng; Sun, Jun

    2016-01-01

    To explore the consumption of energy sources and swimming performance of juvenile Gambusia affinis and Tanichthys albonubes after starvation, contents of glycogen, lipid and protein, burst swimming speeds (Uburst), and critical swimming speeds (Ucrit) at different starvation times (0, 10, 20, 30 and 40 days) were evaluated. The results showed that, at 0 day, contents of glycogen and lipid were significantly lower in G. affinis than those in T. albonubes, whereas no significant difference in content of protein between two experimental fish was found. Swimming speeds in G. affinis were significantly lower than those in T. albonubes for all swimming performances. After different starvation scenarios, content of glycogen both in G. affinis and T. albonubes decreased significantly in power function trend with starvation time and were close to zero after starvation for 10 days, whereas the contents of lipid and protein were linearly significantly decreased. The slope of line regression equation between content of lipid and starvation time in G. affinis was significantly lower than that in T. albonubes, whereas there was a significantly higher slope of line equation between content of protein and starvation time in G. affinis. 40 days later, the consumption rate of glycogen both in G. affinis and T. albonubes were significantly higher than that of lipid, while the consumption rate of protein was the least. Consumption amounts of glycogen in all experimental fish were the least, G. affinis consumed more protein than lipid, and T. albonubes consumed more lipid than protein. Uburst and Ucrit decreased significantly linearly with starvation time for all experimental fish. Slope of linear equation between Uburst and starvation time was not significantly different between G. affinis and T. albonubes. However, the straight slope between Ucrit and starvation time was significantly lower in G. affinis than that in T. albonubes. These findings indicated that there was close

  6. Biologia reprodutiva de Suiriri affinis e S. islerorum (Aves: Tyrannidae no cerrado do Brasil central

    Directory of Open Access Journals (Sweden)

    Leonardo Esteves Lopes

    2005-01-01

    Full Text Available A biologia reprodutiva de Suiriri affinis (suiriri-do-cerrado e S. islerorum (suiriri-da-chapada é descrita pela primeira vez. O ninho de S. affinis é em forma de cesto raso, sendo construído com fibras vegetais e forrado por painas, sendo todas essas camadas firmemente unidas por grande quantidade de teia de aranha. O seu exterior é ornamentado com liquens e fragmentos de folhas secas. O ninho é apoiado pela base e laterais entre dois ou mais ramos divergentes. Embora superficialmente similar, o ninho de S. islerorum apresenta várias diferenças, sendo mais baixo, raso e apoiado pelas laterais entre uma forquilha. O seu interior é forrado por uma camada adicional de fibras vegetais por sobre as painas. A construção dos ninhos de ambas as espécies é exclusividade das fêmeas. Os ovos de S. affinis são branco-perolados (média de 20,8 x 15,1 mm, 2,5 g, enquanto que os de S. islerorum são creme claro (20,4 x 15,4 mm, 2,4 g, apresentando uma coroa de manchas marrons escuras ao redor do pólo rombo. Os filhotes de S. affinis apresentam a cabeça, superfície dorsal e coberteiras das asas marcadas por abundantes e diminutas manchas brancas, enquanto que os filhotes de S. islerorum são semelhantes aos adultos. A incubação é realizada exclusivamente pelas fêmeas, sendo estimada em 15,2 dias para ambas as espécies. Já os filhotes de S. affinis e S. islerorum permanecem no ninho por 18,9 e 18,3 dias, respectivamente. Algumas evidências sugerem que S. affinis apresenta alguma forma de reprodução cooperativa.The breeding biology of Suiriri affinis (Campo Suiriri and S. islerorum (Chapada Flycatcher is described for the first time. The nest of S. affinis is a basket constructed mainly with vegetable fibers and lined with a thick layer of silk cotton. All its exterior is ornamented with lichens and dry leaf fragments. All those layers are firmly attached to each other by a large amount of spider web. The nest is supported by its bottom

  7. Biologia reprodutiva de Suiriri affinis e S. islerorum (Aves: Tyrannidae) no cerrado do Brasil central

    OpenAIRE

    Leonardo Esteves Lopes; Miguel Ângelo Marini

    2005-01-01

    A biologia reprodutiva de Suiriri affinis (suiriri-do-cerrado) e S. islerorum (suiriri-da-chapada) é descrita pela primeira vez. O ninho de S. affinis é em forma de cesto raso, sendo construído com fibras vegetais e forrado por painas, sendo todas essas camadas firmemente unidas por grande quantidade de teia de aranha. O seu exterior é ornamentado com liquens e fragmentos de folhas secas. O ninho é apoiado pela base e laterais entre dois ou mais ramos divergentes. Embora superficialmente simi...

  8. Economic feasibility of copepod production for commercial use

    DEFF Research Database (Denmark)

    Gedefaw Abate, Tenaw; Nielsen, Rasmus; Nielsen, Max

    2015-01-01

    of producing copepods for commercial application. This is the first empirical study to investigate the economic feasibility of copepod production for commercial use. To this end, a standard cost-benefit analysis based on a prototype production facility of Acartia tonsa (Dana) eggs at Roskilde University...... production for marine finfish aquaculture. Furthermore, the study also highlights the economic benefits of production and utilization of copepods on productivity and species diversification in marine finfish aquaculture....

  9. COPEPOD: The Coastal & Oceanic Plankton Ecology, Production, & Observation Database

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Coastal & Oceanic Plankton Ecology, Production, & Observation Database (COPEPOD) provides NMFS scientists with quality-controlled, globally distributed...

  10. Ocean acidification challenges copepod phenotypic plasticity

    Science.gov (United States)

    Vehmaa, Anu; Almén, Anna-Karin; Brutemark, Andreas; Paul, Allanah; Riebesell, Ulf; Furuhagen, Sara; Engström-Öst, Jonna

    2016-11-01

    Ocean acidification is challenging phenotypic plasticity of individuals and populations. Calanoid copepods (zooplankton) are shown to be fairly plastic against altered pH conditions, and laboratory studies indicate that transgenerational effects are one mechanism behind this plasticity. We studied phenotypic plasticity of the copepod Acartia sp. in the course of a pelagic, large-volume mesocosm study that was conducted to investigate ecosystem and biogeochemical responses to ocean acidification. We measured copepod egg production rate, egg-hatching success, adult female size and adult female antioxidant capacity (ORAC) as a function of acidification (fCO2 ˜ 365-1231 µatm) and as a function of quantity and quality of their diet. We used an egg transplant experiment to reveal whether transgenerational effects can alleviate the possible negative effects of ocean acidification on offspring development. We found significant negative effects of ocean acidification on adult female size. In addition, we found signs of a possible threshold at high fCO2, above which adaptive maternal effects cannot alleviate the negative effects of acidification on egg-hatching and nauplii development. We did not find support for the hypothesis that insufficient food quantity (total particulate carbon < 55 µm) or quality (C : N) weakens the transgenerational effects. However, females with high-ORAC-produced eggs with high hatching success. Overall, these results indicate that Acartia sp. could be affected by projected near-future CO2 levels.

  11. Copepod Foraging on the Basis of Food Nutritional Quality: Can Copepods Really Choose?

    Science.gov (United States)

    Isari, Stamatina; Antό, Meritxell; Saiz, Enric

    2013-01-01

    Copepods have been considered capable of selective feeding based on several factors (i.e., prey size, toxicity, and motility). However, their selective feeding behaviour as a function of food quality remains poorly understood, despite the potential impact of such a process on copepod fitness and trophodynamics. In this study, we aimed to evaluate the ability of copepods to feed selectively according to the nutritional value of the prey. We investigated the feeding performance of the calanoid copepod Acartia grani under nutritionally distinct diets of the dinoflagellate Heterocapsa sp. (nutrient-replete, N-depleted and P-depleted) using unialgal suspensions and mixtures of prey (nutrient-replete vs. nutrient-depleted). Despite the distinct cell elemental composition among algal treatments (e.g., C:N:P molar ratios) and the clear dietary impact on egg production rates (generally higher number of eggs under a nutrient-replete diet), no impact on copepod feeding rates was observed. All unialgal suspensions were cleared at similar rates, and this pattern was independent of food concentration. When the prey were offered as mixtures, we did not detect selective behaviour in either the N-limitation (nutrient-replete vs. N-depleted Heterocapsa cells) or P-limitation (nutrient-replete vs. P-depleted Heterocapsa cells) experiments. The lack of selectivity observed in the current study contrasts with previous observations, in which stronger nutritional differences were tested. Under normal natural circumstances, nutritional differences in natural prey assemblages might not be sufficiently strong to trigger a selective response in copepods based on that factor alone. In addition, our results suggest that nutritional quality might depend not only on the growing conditions but also on the inherent taxonomical properties of the prey. PMID:24386411

  12. Two myxozoans from the urinary tract of topsmelt, Atherinops affinis

    Science.gov (United States)

    Sanders, Justin L.; Jaramillo, Alejandra G.; Ashford, Jacob E.; Feist, Stephen W.; Lafferty, Kevin D.; Kent, Michael L.

    2015-01-01

    Two myxozoan species were observed in the kidney of topsmelt, Atherinops affinis, during a survey of parasites of estuarine fishes in the Carpinteria Salt Marsh Reserve, California. Fish collected on three dates in 2012 and 2013 were sectioned and examined histologically. Large extrasporogonic stages occurred in the renal interstitium of several fish from the first two collections (5/8, 11/20, respectively), and, in some fish, these replaced over 80% of the kidney. In addition, presporogonic and polysporogonic stages occurred in the lumen of the renal tubules, collecting and mesonephric ducts. The latter contained subspherical spores with up to 4 polar capsules, consistent with the genus Chloromyxum. For the third collection (15 May 2013, n=30), we portioned kidneys for examination by histology, wet mount, and DNA extraction for small subunit ribosomal gene sequencing. Histology showed the large extrasporogonic forms in the kidney interstitium of 3 fish, and 2 other fish with subspherical myxospores in the lumen of the renal tubules with smooth valves and two spherical polar capsules consistent with the genus Sphaerospora. Chloromyxum-type myxospores were observed in the renal tubules of one fish by wet mount. Sequencing of the kidney tissue from this fish yielded a partial SSU rDNA sequence of 1769 bp. Phylogenetic reconstruction suggested this organism to be a novel species of Chloromyxum, most similar to Chloromyxum careni (84% similarity). In addition, subspherical myxospores with smooth valves and two spherical polar capsules consistent with the genus Sphaerospora were observed in wet mounts of 2 fish. Sequencing of the kidney tissue from 1 fish yielded a partial SSU rDNA sequence of 1937 bp. Phylogenetic reconstruction suggests this organism to be a novel species of Sphaerospora most closely related to Sphaerospora epinepheli (93%). We conclude that these organisms represent novel species of the genera Chloromyxum and Sphaerospora based on host, location, and

  13. Two Myxozoans from the Urinary Tract of Topsmelt, Atherinops affinis.

    Science.gov (United States)

    Sanders, Justin L; Jaramillo, Alejandra G; Ashford, Jacob E; Feist, Stephen W; Lafferty, Kevin D; Kent, Michael L

    2015-10-01

    Two myxozoan species were observed in the kidney of topsmelt, Atherinops affinis , during a survey of parasites of estuarine fishes in the Carpinteria Salt Marsh Reserve, California. Fish collected on 3 dates in 2012 and 2013 were sectioned and examined histologically. Large extrasporogonic stages occurred in the renal interstitium of several fish from the first 2 collections (5/8, 11/20, respectively) and, in some fish, these replaced over 80% of the kidney. In addition, presporogonic and polysporogonic stages occurred in the lumen of the renal tubules, collecting ducts, and mesonephric ducts. The latter contained subspherical spores with up to 4 polar capsules, consistent with the genus Chloromyxum. For the third collection (15 May 2013, n = 30), we portioned kidneys for examination by histology, wet mount, and DNA extraction for small subunit ribosomal (SSU rDNA) gene sequencing. Histology showed the large extrasporogonic forms in the kidney interstitium of 3 fish and showed 2 other fish with subspherical myxospores in the lumen of the renal tubules with smooth valves and 2 spherical polar capsules consistent with the genus Sphaerospora. Chloromyxum-type myxospores were observed in the renal tubules of 1 fish by wet mount. Sequencing of the kidney tissue from this fish yielded a partial SSU rDNA sequence of 1,769 base pairs (bp). Phylogenetic reconstruction suggested this organism to be a novel species of Chloromyxum, most similar to Chloromyxum careni (84% similarity). In addition, subspherical myxospores with smooth valves and 2 spherical polar capsules consistent with the genus Sphaerospora were observed in wet mounts of 2 fish. Sequencing of the kidney tissue from 1 fish yielded a partial SSU rDNA sequence of 1,937 bp. Phylogenetic reconstruction suggests this organism to be a novel species of Sphaerospora most closely related to Sphaerospora epinepheli (93%). We conclude that these organisms represent novel species of the genera Chloromyxum and Sphaerospora

  14. Polyopes affinis alleviates airway inflammation in a murine model of allergic asthma

    Indian Academy of Sciences (India)

    Dae-Sung Lee; Won Sun Park; Soo-Jin Heo; Seon-Heui Cha; Daekyung Kim; You-Jin Jeon; Sae-Gwang Park; Su-Kil Seo; Jung Sik Choi; Sung-Jae Park; Eun Bo Shim; Il-Whan Choi; Won-Kyo Jung

    2011-12-01

    Marine algae have been utilized in food as well as medicine products for a variety of purposes. The purpose of this study was to determine whether an ethanol extract of Polyopes affinis (P.affinis) can inhibit the pathogenesis of T helper 2 (Th2)-mediated allergen-induced airway inflammation in a murine model of asthma. Mice that were sensitized and challenged with ovalbumin (OVA) evidenced typical asthmatic reactions such as the following: an increase in the number of eosinophils in the bronchoalveolar lavage (BAL) fluid; a marked influx of inflammatory cells into the lung around blood vessels and airways as well as the narrowing of the airway luminal; the development of airway hyperresponsiveness (AHR); the presence of pulmonary Th2 cytokines; and the presence of allergen-specific immunoglobulin E (IgE) in the serum. The successive intraperitoneal administration of P. affinis ethanolic extracts before the last airway OVA-challenge resulted in a significant inhibition of all asthmatic reactions. These data suggest that P. affinis ethanolic extracts possess therapeutic potential for the treatment of pulmonary allergic disorders such as allergic asthma.

  15. Copepods use chemical trails to find sinking marine snow aggregates

    DEFF Research Database (Denmark)

    Lombard, Fabien; Koski, Marja; Kiørboe, Thomas

    2013-01-01

    Copepods are major consumers of sinking marine particles and hence reduce the efficiency of the biological carbon pump. Their high abundance on marine snow suggests that they can detect sinking particles remotely. By means of laboratory observations, we show that the copepod Temora longicornis ca...

  16. Re-assessing copepod growth using the Moult Rate method

    DEFF Research Database (Denmark)

    Hirst, Andrew G.; Keister, J. E.; Richardson, A. J.

    2014-01-01

    Estimating growth and production rates of mesozooplankton, and copepods in particular, is important in describing flows of material and energy though pelagic systems. Over the past 30 years, the Moult Rate (MR) method has been used to estimate juvenile copepod growth rates in ∼40 papers. Yet the ...

  17. Mortality of marine planktonic copepods : global rates and patterns

    DEFF Research Database (Denmark)

    Hirst, A.G.; Kiørboe, Thomas

    2002-01-01

    Using life history theory we make predictions of mortality rates in marine epi-pelagic copepods from field estimates of adult fecundity, development times and adult sex ratios. Predicted mortality increases with temperature in both broadcast and sac spawning copepods, and declines with body weight...

  18. Propulsion efficiency and imposed flow fields of a copepod jump

    DEFF Research Database (Denmark)

    Jiang, H.; Kiørboe, Thomas

    2011-01-01

    velocity vectors pointing towards the copepod; such a flow field may inform the predator of the whereabouts of the escaping copepod prey. High Froude propulsion efficiency (0.94–0.98) was obtained for individual power stroke durations of all simulated jumps. This is unusual for small aquatic organisms...

  19. Does copepods influence dusky grouper (Epinephelus marginatus early development?

    Directory of Open Access Journals (Sweden)

    Monica Mateus

    2014-06-01

    Full Text Available Good knowledge on the development of early life stages is essential for successful conservation programs of threatened fish species. Diet and rearing system affects early life survival and juvenile quality. Copepods are the natural food of fish larvae in the wild possessing high nutritional value, when compared with live feeds used in aquaculture (rotifers and artemia, and a wide range of size classes. Rearing systems with low water column disturbance and low larval densities enhanced the survival of fragile fish larvae. The aim of this work is to evaluate the effect of the introduction of copepods in the diet of early dusky grouper larvae reared in controlled mesocosm systems using larval development and juvenile quality as indicators. Two feeding protocols were tested, one composed only by rotifers (Brachionus plicatilis, brine shrimp (Artemia spp. and dry feed and the other supplemented with copepods (Paracartia grani from mouth opening (2 day after hatching - DAH to 8 DAH. Feeding behavior, growth, survival, skeletal malformations and digestive enzymes activity was assessed at different developmental stages. The addition of copepods to the early larvae diet of dusky grouper resulted in faster development and higher survival rates. Larvae fed with copepods improved their development. At 20 DAH all larvae reared at the mesocosm with copedods were already at the stage of post-flexion while in the system without copepods this stage was attained later. At 25 DAH only 64% of the larvae were in post flexion in the mesoscosm without copepods. At 30 DAH larvae supplemented with copepods attained an acidic digestion (high specific activity of pepsin earlier than at the system without copepods. In this last system alkaline digestion (trypsin specific activity, characteristic of early larval stages, was significantly higher reinforcing the faster development of larvae fed with copepods. In both systems the incidence of skeletal malformations was low.

  20. Feeding traits of Gambusia affinis and their relations with zooplankton and environmental factors%食蚊鱼摄食特性及其与浮游动物和环境因子的关系

    Institute of Scientific and Technical Information of China (English)

    姚达章; 陈国柱; 林小涛; 赵天; 徐采

    2012-01-01

    2008年11月-2009年4月,利用分时段采样法对广州暨南大学明湖内食蚊鱼在秋季(11月)、冬季(12-2月)、春季(3-4月)3个季节的摄食特性进行了研究,探讨其与湖内浮游动物群体数量动态、光照和水温的关系.结果表明:食蚊鱼主要以浮游动物为食,对枝角类和桡足类有较强的选择性;明湖日平均水温与浮游动物日平均丰度在3个季节间有显著差异,而食蚊鱼消化道饱满指数的差异不显著;食蚊鱼消化道饱满指数在这3个季节的变化与浮游动物丰度、水温、光照在这3个季节的变化无明显的相关;无论哪个季节,食蚊鱼在白天时段( 10∶00-18∶00)的消化道饱满指数均高于夜间(22∶00-6∶00),表现出白天高峰型的摄食节律;光照是影响食蚊鱼昼夜摄食节律的主要因素,而水温、浮游动物丰度的昼夜变化与食蚊鱼的昼夜摄食节律没有显著相关.%From November 2008 to April 2009, an investigation was conducted to understand the feeding traits of Gambusia affinis and their relations with the dynamics of zooplankton population, water temperature, and light intensity in the Minghu pond in Jinan University campus in autumn ( November ) , winter ( December - February ) , and spring ( March - April). In the pond, G. Affinis mainly fed zooplankton, especially cladocera and copepod. The daily mean temperature and daily mean abundance of the zooplankton changed significantly with the three seasons, but the repletion index of the alimentary canal of G. Affinis had little change. The repletion index had no significant relationships with the zooplankton abundance, water temperature, and light intensities in the three seasons. No matter what season, the G. Affinis had a day-night feeding rhythm, and its repletion index in the daytime (10:00-18:00) was higher than that in the nighttime (22:00-6:00). The diurnal feeding rhythm of G. Affinis was significantly affected by light intensity, but not

  1. Environmental cues and constraints affecting the seasonality of dominant calanoid copepods in brackish, coastal waters: a case study of Acartia, Temora and Eurytemora species in the south-west Baltic

    DEFF Research Database (Denmark)

    Diekmann, A. Berenike S.; Clemmesen, Catriona; St. John, Michael A.;

    2012-01-01

    Information on physiological rates and tolerances helps one gain a cause-and-effect understanding of the role that some environmental (bottom–up) factors play in regulating the seasonality and productivity of key species. We combined the results of laboratory experiments on reproductive success...

  2. A trait database for marine copepods

    Science.gov (United States)

    Brun, Philipp; Payne, Mark R.; Kiørboe, Thomas

    2017-02-01

    The trait-based approach is gaining increasing popularity in marine plankton ecology but the field urgently needs more and easier accessible trait data to advance. We compiled trait information on marine pelagic copepods, a major group of zooplankton, from the published literature and from experts and organized the data into a structured database. We collected 9306 records for 14 functional traits. Particular attention was given to body size, feeding mode, egg size, spawning strategy, respiration rate, and myelination (presence of nerve sheathing). Most records were reported at the species level, but some phylogenetically conserved traits, such as myelination, were reported at higher taxonomic levels, allowing the entire diversity of around 10 800 recognized marine copepod species to be covered with a few records. Aside from myelination, data coverage was highest for spawning strategy and body size, while information was more limited for quantitative traits related to reproduction and physiology. The database may be used to investigate relationships between traits, to produce trait biogeographies, or to inform and validate trait-based marine ecosystem models. The data can be downloaded from PANGAEA, http://dx.doi.org/10.1594/PANGAEA.862968" target="_blank">doi:10.1594/PANGAEA.862968.

  3. Numerical simulation of a self-propelled copepod during escape

    Science.gov (United States)

    Sotiropoulos, Fotis; Borazjani, Iman; Malkiel, Edwin; Katz, Josef

    2008-11-01

    Obtaining the 3D flow field, forces, and power is essential for understanding the high accelerations of a copepod during the escap. We carry out numerical simulations to study a free swimming copepod using the sharp-interface immersed boundary, fluid-structure interaction (FSI) approach of Borazjani et al. (J Compu Phys, 2008, 227, p 7587-7620). We use our previous tethered copepod model with a realistic copepod-like body, including all the appendages with the appendages motion prescribed from high-resolution, cinematic dual digital holography. The simulations are performed in a frame of reference attached to the copepod whose velocity is calculated by considering the forces acting on the copepod. The self-propelled simulations are challenging due to the destabilizing effects of the large added mass resulting from the low copepod mass and fast acceleration during the escape. Strongly-coupled FSI with under-relaxation and the Aitken acceleration technique is used to obtain stable and robust FSI iterations. The computed results for the self-propelled model are analyzed and compared with our earlier results for the tethered model.

  4. Impact of a power plant cooling system on copepod and meroplankton survival (Bahía Blanca estuary, Argentina Impacto del sistema de enfriamiento de una central termoeléctrica sobre la supervivencia de copépodos y meroplancton (estuario de Bahía Blanca, Argentina

    Directory of Open Access Journals (Sweden)

    Mónica Susana Hoffmeyer

    2005-09-01

    Full Text Available The impact of a power plant cooling system in the Bahía Blanca estuary (Argentina on the survival of target zooplanktonic organisms (copepods and crustacean larvae and on overall mesozooplankton abundance was evaluated over time. Mortality rates were calculated for juveniles and adults of four key species in the estuary: Acartia tonsa Dana, 1849 and Eurytemora americana Williams, 1906 (native and invading copepods, and larvae of the crab Chasmagnathus granulata Dana, 1851 and the invading cirriped Balanus glandula Darwin, 1854. Mean total mortality values were up to four times higher at the water discharge site than at intake, though for all four species, significant differences were only registered in post-capture mortality. The findings show no evidence of greater larval sensitivity. As expected, the sharpest decrease in overall mesozooplankton abundance was found in areas close to heated water discharge.El impacto del sistema de enfriamiento de una planta termoeléctrica ubicada en el estuario de Bahía Blanca, Argentina, fue evaluado en el tiempo, sobre la supervivencia de especies zooplanctónicas seleccionadas (copépodos y larvas de crustáceos y la abundancia general del meso-zooplancton. Se calcularon tasas de mortalidad de juveniles y adultos de cuatro especies clave en el estuario: Acartia tonsa Dana,1849 y Eurytemora americana Williams,1906 (copépodos nativo e invasor, y larvas del cangrejo Chasmagnathus granulata Dana, 1851 y del cirripedio invasor Balanus glandula Darwin, 1854. Los valores medios hallados de la tasa de mortalidad total, fueron hasta cuatro veces más altos en la descarga que en el agua de entrada al sistema. Sin embargo sólo se registraron diferencias significativas entre estos dos sitios, en los valores de mortalidad post-captura obtenidos para las cuatro especies. Los resultados del estudio no demostraron una mayor sensibilidad larval. Como se esperaba, la disminución más pronunciada en la abundancia general

  5. Ingestion and transfer of microplastics in the planktonic food web.

    Science.gov (United States)

    Setälä, Outi; Fleming-Lehtinen, Vivi; Lehtiniemi, Maiju

    2014-02-01

    Experiments were carried out with different Baltic Sea zooplankton taxa to scan their potential to ingest plastics. Mysid shrimps, copepods, cladocerans, rotifers, polychaete larvae and ciliates were exposed to 10 μm fluorescent polystyrene microspheres. These experiments showed ingestion of microspheres in all taxa studied. The highest percentage of individuals with ingested spheres was found in pelagic polychaete larvae, Marenzelleria spp. Experiments with the copepod Eurytemora affinis and the mysid shrimp Neomysis integer showed egestion of microspheres within 12 h. Food web transfer experiments were done by offering zooplankton labelled with ingested microspheres to mysid shrimps. Microscopy observations of mysid intestine showed the presence of zooplankton prey and microspheres after 3 h incubation. This study shows for the first time the potential of plastic microparticle transfer via planktonic organisms from one trophic level (mesozooplankton) to a higher level (macrozooplankton). The impacts of plastic transfer and possible accumulation in the food web need further investigations.

  6. Molecular and microscopic evidence of viruses in marine copepods.

    Science.gov (United States)

    Dunlap, Darren S; Ng, Terry Fei Fan; Rosario, Karyna; Barbosa, Jorge G; Greco, Anthony M; Breitbart, Mya; Hewson, Ian

    2013-01-22

    As dominant members of marine mesozooplankton communities, copepods play critical roles in oceanic food webs and biogeochemical cycling. Despite the ecological significance of copepods, little is known regarding the causes of copepod mortality, and up to 35% of total copepod mortality cannot be accounted for by predation alone. Viruses have been established as ecologically important infectious agents in the oceans; however, viral infection has not been investigated in mesozooplankton communities. Here we used molecular and microscopic techniques to document viral infection in natural populations of the calanoid copepods Acartia tonsa (Dana) and Labidocera aestiva (Wheeler) in Tampa Bay, FL. Viral metagenomics revealed previously undocumented viruses in each species, named Acartia tonsa copepod circo-like virus (AtCopCV) and Labidocera aestiva copepod circo-like virus (LaCopCV). LaCopCV was found to be extremely prevalent and abundant in L. aestiva populations, with up to 100% prevalence in some samples and average viral loads of 1.13 × 10(5) copies per individual. LaCopCV transcription was also detected in the majority of L. aestiva individuals, indicating viral activity. AtCopCV was sporadically detected in A. tonsa populations year-round, suggesting temporal variability in viral infection dynamics. Finally, virus-like particles of unknown identity were observed in the connective tissues of A. tonsa and L. aestiva by transmission electron microscopy, demonstrating that viruses were actively proliferating in copepod connective tissue as opposed to infecting gut contents, parasites, or symbionts. Taken together, these results provide strong independent lines of evidence for active viral infection in dominant copepod species, indicating that viruses may significantly influence mesozooplankton ecology.

  7. Behavioral Differentiation Induced by Insecticide Lambda-Cyhalothrin in Mosquito Fish, Gambusia affinis

    Directory of Open Access Journals (Sweden)

    Utku GÜNER

    2016-04-01

    Full Text Available Test toxic material, one of most used pesticide, the Lambda cyhalothrin (LCY (TEKVANDO 5EC belongs to a group of chemicals called synthetic pyrethroids and pesticides and potential toxic pollutant contaminating aquatic ecosystems, was investigated in the present study for behavioral toxicology. Mosquito fish, Gambusia affinis (Baird & Girard, 1853 were selected for responses of Lambda cyhalothrin by Using to video-based movement analysis system. Selected 3 different doses 0.1, 0.5 and 0.75 ppm were used analyzed behavioral changes according to control group. The following behaviors were measured: total distance, travelled and average speed for treatment and control groups, maximum and average speed and time moving away from the dose applied point. This suggests that LCY contamination has the potential to significantly affect (p<0.05 the behavior of Mosquito fish, G. affinis.

  8. Production and use of copepods in marine fish larviculture

    DEFF Research Database (Denmark)

    Støttrup, Josianne; Norsker, N.H.

    1997-01-01

    substratum. Two such systems were compared in terms of area productivity and the use of ammonia excretion as a means for controlling feeding of the copepods was investigated. Finally, the potential benefits of the use of copepods as live food for marine fish larvae are discussed. (C) 1997 Elsevier Science B.V...... swimming behaviour in terms of vertical distribution in a typical fish larval tank and the use of T. holothuriae nauplii as live food for first-feeding turbot larvae were investigated. It was possible to cultivate harpacticoid copepods in shallow trays or in continuous bioreactors with large area...

  9. Does copepod size determine food consumption of particulate feeding fish?

    DEFF Research Database (Denmark)

    Deurs, Mikael van; Koski, Marja; Rindorf, Anna

    2014-01-01

    on adult particulate feeding fish is unknown. In the present study, we investigated the hypothesis that the availability of the large copepods determines food consumption and growth conditions of lesser sandeel (Ammodytes marinus) in the North Sea. Analysis of stomach content suggested that food...... consumption is higher for fish feeding on large copepods, and additional calculations revealed how handling time limitation may provide part of the explanation for this relationship. Comparing stomach data and zooplankton samples indicated that lesser sandeel actively target large copepods when...

  10. ESTIMASI PARAMETER POPULASI IKAN TONGKOL KOMO (Euthynnus affinis) DI PERAIRAN LAUT JAWA

    OpenAIRE

    Umi Chodrijah; Thomas Hidayat; Tegoeh Noegroho

    2016-01-01

    Tongkol komo (Euthynnus affinis) yang dikenal dengan nama perdagangan kawa-kawa termasuk dalam family Scombridae. Sebagai ikan pelagis mereka membentuk gerombolan, perenang cepat dan pemakan daging (carnivore). Penelitian tentang estimasi parameter populasi ikan tongkol komo di Laut Jawa didasarkan pada pengumpulan data di Pelabuhan Perikanan Nusantara Pekalongan, pada bulan Februari-Desember 2012. Analisis parameter populasi menggunakan program “Electronic Length Frequency Analysis (ELEFAN-1...

  11. Viability costs of reproduction and behavioral compensation in western mosquitofish (Gambusia affinis.

    Directory of Open Access Journals (Sweden)

    Clinton T Laidlaw

    Full Text Available The cost of reproduction hypothesis suggests that current reproduction has inherent tradeoffs with future reproduction. These tradeoffs can be both in the form of energy allocated to current offspring as opposed to somatic maintenance and future reproduction (allocation costs, or as an increase in mortality as a result of morphological or physiological changes related to reproduction (viability costs. Individuals may be able to decrease viability costs by altering behavior. Female western mosquitofish, Gambusia affinis experience a reduction in swimming ability as a consequence of pregnancy. We test for a viability cost of reproduction, and for behavioral compensation in pregnant female G. affinis by measuring survival of females in early and later stages of pregnancy when exposed to predation. Late-stage pregnant females experience a 70% greater probability of mortality compared to early-stage pregnant females. The presence of a refuge roughly doubled the odds of survival of both early and late-stage pregnant females. However, there was no interaction between refuge availability and stage of pregnancy. These data do not provide evidence for behavioral compensation by female G. affinis for elevated viability costs incurred during later stages of pregnancy. Behavioral compensation may be constrained by other aspects of the cost of reproduction.

  12. A molecular and bioinformatic study on the ochratoxin A (OTA)-producing Aspergillus affinis (section Circumdati).

    Science.gov (United States)

    Davolos, Domenico; Pietrangeli, Biancamaria

    2014-05-01

    Aspergillus affinis (section Circumdati) is a novel ochratoxin A (OTA)-producing species found in submerged riparian decomposing leaves. However, very little is known about its role on the breakdown of plant debris and its ability to degrade carbohydrate polymers. Moreover, its OTA biosynthetic pathway has not yet been explored. In the present paper, we investigated the gene encoding the extracellular alpha-amylase (amyAa) of A. affinis within the evolution of the Aspergillus lineages in relation to the possible use of this enzyme in starch processing. The novel amyAa, despite being related to branches of the Aspergillus species of the sections Terrei and Flavi, formed a distinct phylogenetic branch, which may be of outstanding importance from a biotechnological point of view. Moreover, we identified the polyketide synthase gene (pks) putatively required for the first step of OTA biosynthesis in A. affinis. This otapks was examined in relation to a limited number of orthologous genes available from Aspergillus species of the sections Circumdati and Nigri. Our study highlights the importance of otapks as target genes in the treatment of ochratoxigenic Aspergillus species on a more comprehensive evolutionary basis.

  13. Primer registro para la flora argentina de Ilex affinis (Aquifoliaceae, sustituto de la "yerba mate" First report for Argentina of Ilex affinis (Aquifoliaceae, a "mate" substitute

    Directory of Open Access Journals (Sweden)

    Héctor A. Keller

    2011-06-01

    Full Text Available El hallazgo de Ilex affinis Gardner (Aquifoliaceae en los paredones rocosos y áreas pantanosas del paraje Teyú Cuaré, Misiones, Argentina, permite elevar a siete el número de especies de este género para nuestro país y desplaza al sur el límite austral de dispersión de esta especie. Se describe la especie sobre la base de los ejemplares hallados, y se la ilustra mediante fotografías. Además se presentan consideraciones sobre su distribución, observaciones ecológicas y su relación con la yerba mate (Ilex paraguariensis A. St. Hil..The finding of Ilex affinis Gardner (Aquifoliaceae in the rocky cliffs and swampy places of Teyú Cuaré, Misiones Province, Argentina, raises to seven the number of species of this genus for our country and moves southward the distribution limits of the species. The species is described on the basis of the specimens collected, and it is illustrated by photographies. Moreover, considerations about distribution, ecology and relationships with maté (Ilex paraguariensis A. St. Hil. are given.

  14. Estratégia reprodutiva do peixe voador, Hirundichthys affinis Günther (Osteichthyes, Exocoetidae Reproductive stralegy of the flying fish, Hirundichthys affinis Gunther (Osteichthyes, Exocoetidae

    Directory of Open Access Journals (Sweden)

    Andréa Soares de Araújo

    2002-09-01

    Full Text Available This study was carried out to investigate the reproductive aspects of the flying fish, Hirundichthys affinis Günther, 1866 considering their importance in the fish production of the Rio Grande do Norte State, Brazil. Fish samples were collected from the Municipality of Caiçara do Norte, northern coast of the state, during the period of April, 1999 to April, 2000. The fish were measured, weighed, dissected and the gonads were examined to separate the sex and to determine the stage of maturation. Histological studies were done for microscopic characterization of the gonads. The results indicated that H. affinis had a sexual proportion of 1:1; condition factor was inversely related to the gonadosomatic index during the reproductive phase; and the highest for both sexes was registered during the breeding season. Males and females showed four devolopmental stages of the gonads: immature, initial maturation, mature and spent. Absolute fecundity varied from 4400 to 6400 oocytes, with a mean of 5400. The species presents total spawing and the spawing season occurred in the months of May and June. The rainy season preceeded the occurrence of breeding flying fishes in the coastal waters of Caiçara do Norte.

  15. Strategies for success: Copepods in a seasonal world

    DEFF Research Database (Denmark)

    Sainmont, Julie

    by a short, productive spring blooms, but with relatively little food and harsh conditions for the rest of the year. Due to their world-wide dominance in biomass, and their importance in the food webs, copepods are fairly well studied. However, the success of their complex life-history strategies remain open......Amongst the zooplankton community, copepods display complex and diverse life history strategies, which could explain their wide success in the world ocean. Specically, in temperate and high latitude ecosystems, copepods are subject to \\boom and bust" conditions where annual cycles are punctuated...... scientic questions, in particular, how these are attuned to environmental conditions, and how these may be compromised by climate change. Due to their ability to concentrate lipids in their small bodies, copepods are indeed of great ecological signicance as they are an important link between phytoplankton...

  16. The fluid dynamics of swimming by jumping in copepods

    DEFF Research Database (Denmark)

    Jiang, Houshuo; Kiørboe, Thomas

    2011-01-01

    Copepods swim either continuously by vibrating their feeding appendages or erratically by repeatedly beating their swimming legs resulting in a series of small jumps. The two swimming modes generate different hydrodynamic disturbances and therefore expose the swimmers differently to rheotactic...... limited and temporally ephemeral owing to jump-impulsiveness and viscous decay. In contrast, continuous steady swimming generates two well-extended long-lasting momentum jets both in front of and behind the swimmer, as suggested by the well-known steady stresslet model. Based on the observed jump-swimming...... kinematics of a small copepod Oithona davisae, we further showed that jump-swimming produces a hydrodynamic disturbance with much smaller spatial extension and shorter temporal duration than that produced by a same-size copepod cruising steadily at the same average translating velocity. Hence, small copepods...

  17. The fluid dynamics of swimming by jumping in copepods

    DEFF Research Database (Denmark)

    Jiang, Houshuo; Kiørboe, Thomas

    2011-01-01

    Copepods swim either continuously by vibrating their feeding appendages or erratically by repeatedly beating their swimming legs resulting in a series of small jumps. The two swimming modes generate different hydrodynamic disturbances and therefore expose the swimmers differently to rheotactic...... limited and temporally ephemeral owing to jump-impulsiveness and viscous decay. In contrast, continuous steady swimming generates two well-extended long-lasting momentum jets both in front of and behind the swimmer, as suggested by the well-known steady stresslet model. Based on the observed jump-swimming...... kinematics of a small copepod Oithona davisae, we further showed that jump-swimming produces a hydrodynamic disturbance with much smaller spatial extension and shorter temporal duration than that produced by a same-size copepod cruising steadily at the same average translating velocity. Hence, small copepods...

  18. Distribution of pelagic harpacticoid copepods from the Indian ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Haridas, P.; Rao, T.S.S.

    Pelagic harpacticoid copepods have been studied from the International Indian Ocean Expedition collections. Macrosetella gracilis and Miracia efferata were the most common species of harpacticoids with high densities near land masses. Other three...

  19. Development of copepod nauplii to copepodites

    DEFF Research Database (Denmark)

    Andersen, Henrik Rasmus; Wollenberger, Leah; Halling-Sørensen, Bent;

    2001-01-01

    of the 17 test compounds had 50% lethal concentration to 50% effective concentration (EC50) ratios higher than 10. The results suggest that naupliar development, as a parameter, is able to detect hormonal disrupters in addition to other chemicals that have other specific modes of action.......Test compounds including natural hormones, endocrine disrupters, environmentally occurring compounds, and reference compounds were tested for acute toxicity and inhibitory effect on larval development in the copepod Acartia tonsa. Three compounds, 17a-ethinylestradiol, p-octylphenol, and tamoxifen......, known for their differing effects on the vertebrate estrogen system, were potent inhibitors of naupliar development. Other estrogens, 17b-estradiol, estrone, and bisphenol A, had little potency. Testosterone and progesterone did not inhibit development, but the antiandrogen flutamide had inhibitory...

  20. Copepod flow modes and modulation: a modelling study of the water currents produced by an unsteadily swimming copepod

    OpenAIRE

    2007-01-01

    Video observation has shown that feeding-current-producing calanoid copepods modulate their feeding currents by displaying a sequence of different swimming behaviours during a time period of up to tens of seconds. In order to understand the feeding-current modulation process, we numerically modelled the steady feeding currents for different modes of observed copepod motion behaviours (i.e. free sinking, partial sinking, hovering, vertical swimming upward and horizontal swimming backward or fo...

  1. Notes on a mating event of the deep-sea crab Chaecon affinis in the Gorringe Bank (NE Atlantic)

    Science.gov (United States)

    Hilário, A.; Cunha, M. R.

    2013-08-01

    The deep-water red crab Chaceon affinis is the largest species of the family Geryonidae. Unlike other species of the same genus, C. affinis is not yet subject to intense commercial exploitation but it has been appointed as a new target resource in European waters, in spite of the lack of information on its biology, life cycle and distribution, which is essential to provide advice for a sustainable exploitation. Here we report for the first time the presence of C. affinis in the Gorringe Bank and give the first account of the mating behavior of this species. All mating pairs were found at the interface of the Mediterranean Outflow Water with North Atlantic Deep Water, suggesting that environmental parameters associated with the interface of these water masses may be relevant for mating in this species. The majority of C. affinis was mating which is an indication of synchrony and reproductive seasonality. A biennial female reproductive cycle is hypothesized, involving molting and mating in the first year with subsequent oviposition during the autumn, and spawning during spring of the second year. We suggest that synchrony and seasonality in the reproduction of C. affinis is linked to the formation of phytoplankton blooms in surface waters, with females carrying embryos from autumn to spring, possibly timing the release of planktotrophic larvae to exploit a seasonal peak in surface productivity and its export.

  2. Dieta e comportamento de forrageamento de Suiriri affinis e S. islerorum (Aves, Tyrannidae) em um cerrado do Brasil central Diet and foraging behavior of Suiriri affinis and S. islerorum (Aves, Tyrannidae) in a central Brazilian cerrado

    OpenAIRE

    Leonardo E. Lopes

    2005-01-01

    Foi estudado o comportamento de forrageamento de Suiriri affinis (suiriri-do-cerrado) e S. islerorum (suiriri-da-chapada), duas espécies de Tyrannidae que ocorrem em sintopia nos cerrados do Brasil central. Durante o ano de 2003 foram registradas 188 observações de forrageamento para S. affinis e 150 para S. islerorum. Foram encontradas diferenças significativas entre as duas espécies em relação à altura e substrato de forrageamento, fitofisionomia utilizada e densidade da folhagem no local d...

  3. Ecology and Distribution of Copepods from the Salt Pan Ecosystems of Mumbai, West Coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Stephen, R.; Jayalakshmy, K.V.; NaveenKumar, K.R.; Nair, V.R.

    Ecology, distribution and diversity of Copepod collected from two salt pans of Mumbai, India, are presented. Copepods, the mai zooplankton components, consisted mainly of Bestiolina similis, Acartia southwelli, Oithona sp., O. similis, O. hebes...

  4. Distribution and diversity of copepods in the Mandovi-Zuari estuarine system, Goa

    Digital Repository Service at National Institute of Oceanography (India)

    Goswami, S.C.

    Copepod species number dwindled sharply during the rainy season (June to September) except in Zuari Estuary where comparatively more saline conditions were recorded (1.33 to 29.84 ppt) Postmonsoon period (October to January) was characterised with copepod...

  5. Distribution of copepods from the polluted and unpolluted regions off Bombay

    Digital Repository Service at National Institute of Oceanography (India)

    Gajbhiye, S.N.; JiyalalRam, M.J.; Desai, B.N.

    genera of copepods recorded, Paracalanus, Acrocalanus, Acartia, and Oithona were the most common. The polluted regions of Mahim and Thana creek were characterised by the dominance of Paracalanus, Oithona and Acartia. The generic diversity of copepods...

  6. Linking sub-cellular biomarkers to embryo aberrations in the benthic amphipod Monoporeia affinis.

    Science.gov (United States)

    Reutgard, Martin; Furuhagen, Sara

    2016-04-01

    To adequately assess and monitor environmental status in the aquatic environment a broad approach is needed that integrates physical variables, chemical analyses and biological effects at different levels of the biological organization. Embryo aberrations in the Baltic Sea key species Monoporeia affinis can be induced by both metals and organic substances as well as by hypoxia, increasing temperatures and malnutrition. This amphipod has therefore been used for more than three decades as a biological effect indicator in monitoring and assessment of chemical pollution and environmental stress. However, little is known about the sub-cellular mechanisms underlying embryo aberrations. An improved mechanistic understanding may open up the possibility of including sub-cellular alterations as sensitive warning signals of stress-induced embryo aberrations. In the present study, M. affinis was exposed in microcosms to 4 different sediments from the Baltic Sea. After 88-95 days of exposure, survival and fecundity were determined as well as the frequency and type of embryo aberrations. Moreover, oxygen radical absorption capacity (ORAC) was assayed as a proxy for antioxidant defense, thiobarbituric acid reactive substances (TBARS) level as a measure of lipid peroxidation and acetylcholinesterase (AChE) activity as an indicator of neurotoxicity. The results show that AChE and ORAC can be linked to the frequency of malformed embryos and arrested embryo development. The occurrence of dead broods was significantly associated with elevated TBARS levels. It can be concluded that these sub-cellular biomarkers are indicative of effects that could affect Darwinian fitness and that oxidative stress is a likely mechanism in the development of aberrant embryos in M. affinis.

  7. Status and recommendations on marine copepod cultivation for use as live feed

    DEFF Research Database (Denmark)

    Drillet, Guillaume; Frouël, Stéphane; Sichlau, Mie Hylstofte

    2011-01-01

    Copepods are important crustaceans studied because of their key role in ecology, trophic biology, fisheries management, in modeling the flow of energy and matter, ecotoxicology, aquaculture and aquarium trade. This paper discusses various aspects of the state of knowledge of copepod culture at la...... of probiotics for improving the fitness of copepod cultures; and 6) encourage copepod producers/retailers to use/develop an efficient sales and marketing strategy....

  8. Fecundity of the Hypostomus affinis (Siluriformes, Loricariidae) in the Lajes Reservoir, Rio de Janeiro, Brazil

    OpenAIRE

    Duarte,Silvana; Araújo,Francisco Gerson

    2014-01-01

    The armored catfish Hypostomus affinis is a widespread Loricariidae fish in the Lajes Reservoir (22o42’-22o50’ S; 43o53’-44o05’ W), the largest lentic environment in the Rio de Janeiro State, but little is known about their reproductive biology. One hundred and twenty five females, captured from January 1996 to December 1997, were used to assess ovarian development (29 were used to determine fecundity). The oocyte distribution by size-diameter classes revealed the occurrence of two modes sugg...

  9. Micronucleus Test, Nuclear Abnormalities and Accumulation of Cu and Cd on Gambusia affinis (Baird & Girard, 1853)

    OpenAIRE

    Güner, Utku; Dilek, Fulya; Muranlı, Gökalp

    2011-01-01

    In the present work the induction of micronuclei (MNi) and nuclear abnormalities (NAs) in erythrocytes and Cu and Cd accumulation in whole body of Gambusia affinis were studied. Fish were exposed to two different Cu and Cd concentrations, 0.1 ppm and 1 ppm, for 1 and 2 weeks periods and to Cu-Cd combination (0.1 ppm Cu + 0.1 ppm Cd) for 2 weeks period using a semi-static renewal system. Micronucleus and nuclear abnormality analysis were carried out on peripheral blood erythrocytes. When fish...

  10. Case report: epizootic of coccidiosis in free-flying lesser scaup (Aythya affinis)

    Science.gov (United States)

    Windingstad, R.M.; McDonald, M.E.; Locke, L.N.; Kerr, S.M.; Sinn, J.A.

    1980-01-01

    A coccidiosis epizootic has occurred in lesser scaup (Aythya affinis) at Bluestem Reservoir in eastern Nebraska during the spring in each of three recent years: 1976-1978. Losses peaked during the period from mid-March through April. As much as 29% of the peak population of scaup using the reservoir died. Necropsies of 72 of the nearly 1390 scaup that died revealed destruction and sloughing of the intestinal mucosa and associated hemorrhaging. Fibrinonecrotic cores were frequently found in the intestinal lumens. Scrapings from the intestinal mucosal contained massive numbers of oocysts of the coccidian Eimeria aythyae. This is the first report of recurrent epizootics of coccidiosis in freeflying waterfowl.

  11. Dieta e comportamento de forrageamento de Suiriri affinis e S. islerorum (Aves, Tyrannidae) em um cerrado do Brasil central

    OpenAIRE

    Leonardo E. Lopes

    2005-01-01

    Foi estudado o comportamento de forrageamento de Suiriri affinis (suiriri-do-cerrado) e S. islerorum (suiriri-da-chapada), duas espécies de Tyrannidae que ocorrem em sintopia nos cerrados do Brasil central. Durante o ano de 2003 foram registradas 188 observações de forrageamento para S. affinis e 150 para S. islerorum. Foram encontradas diferenças significativas entre as duas espécies em relação à altura e substrato de forrageamento, fitofisionomia utilizada e densidade da folhagem no local d...

  12. History repeats itself: genomic divergence in copepods.

    Science.gov (United States)

    Renaut, Sébastien; Dion-Côté, Anne-Marie

    2016-04-01

    Press stop, erase everything from now till some arbitrary time in the past and start recording life as it evolves once again. Would you see the same tape of life playing itself over and over, or would a different story unfold every time? The late Steven Jay Gould called this experiment replaying the tape of life and argued that any replay of the tape would lead evolution down a pathway radically different from the road actually taken (Gould 1989). This thought experiment has puzzled evolutionary biologists for a long time: how repeatable are evolutionary events? And if history does indeed repeat itself, what are the factors that may help us predict the path taken? A powerful means to address these questions at a small evolutionary scale is to study closely related populations that have evolved independently, under similar environmental conditions. This is precisely what Pereira et al. (2016) set out to do using marine copepods Tigriopus californicus, and present their results in this issue of Molecular Ecology. They show that evolution can be repeatable and even partly predictable, at least at the molecular level. As expected from theory, patterns of divergence were shaped by natural selection. At the same time, strong genetic drift due to small population sizes also constrained evolution down a similar evolutionary road, and probably contributed to repeatable patterns of genomic divergence.

  13. Hydrocarbon contamination decreases mating success in a marine planktonic copepod.

    Directory of Open Access Journals (Sweden)

    Laurent Seuront

    Full Text Available The mating behavior and the mating success of copepods rely on chemoreception to locate and track a sexual partner. However, the potential impact of the water-soluble fraction of hydrocarbons on these aspects of copepod reproduction has never been tested despite the widely acknowledged acute chemosensory abilities of copepods. I examined whether three concentrations of the water-soluble fraction of diesel oil (0.01%, 0.1% and 1% impacts (i the swimming behavior of both adult males and females of the widespread calanoid copepod Temora longcornis, and (ii the ability of males to locate, track and mate with females. The three concentrations of the water-soluble fraction of diesel oil (WSF significantly and non-significantly affect female and male swimming velocities, respectively. In contrast, both the complexity of male and female swimming paths significantly decreased with increasing WSF concentrations, hence suggesting a sex-specific sensitivity to WSF contaminated seawater. In addition, the three WSF concentrations impacted both T. longicornis mating behavior and mating success. Specifically, the ability of males to detect female pheromone trails, to accurately follow trails and to successfully track a female significantly decreased with increasing WSF concentrations. This led to a significant decrease in contact and capture rates from control to WSF contaminated seawater. These results indicate that hydrocarbon contamination of seawater decreases the ability of male copepods to detect and track a female, hence suggest an overall impact on population fitness and dynamics.

  14. Hydrocarbon contamination decreases mating success in a marine planktonic copepod.

    Science.gov (United States)

    Seuront, Laurent

    2011-01-01

    The mating behavior and the mating success of copepods rely on chemoreception to locate and track a sexual partner. However, the potential impact of the water-soluble fraction of hydrocarbons on these aspects of copepod reproduction has never been tested despite the widely acknowledged acute chemosensory abilities of copepods. I examined whether three concentrations of the water-soluble fraction of diesel oil (0.01%, 0.1% and 1%) impacts (i) the swimming behavior of both adult males and females of the widespread calanoid copepod Temora longcornis, and (ii) the ability of males to locate, track and mate with females. The three concentrations of the water-soluble fraction of diesel oil (WSF) significantly and non-significantly affect female and male swimming velocities, respectively. In contrast, both the complexity of male and female swimming paths significantly decreased with increasing WSF concentrations, hence suggesting a sex-specific sensitivity to WSF contaminated seawater. In addition, the three WSF concentrations impacted both T. longicornis mating behavior and mating success. Specifically, the ability of males to detect female pheromone trails, to accurately follow trails and to successfully track a female significantly decreased with increasing WSF concentrations. This led to a significant decrease in contact and capture rates from control to WSF contaminated seawater. These results indicate that hydrocarbon contamination of seawater decreases the ability of male copepods to detect and track a female, hence suggest an overall impact on population fitness and dynamics.

  15. Copepod assemblages in a highly complex hydrographic region

    Science.gov (United States)

    Berasategui, A. D.; Menu Marque, S.; Gómez-Erache, M.; Ramírez, F. C.; Mianzan, H. W.; Acha, E. M.

    2006-02-01

    Community structure and diversity patterns of planktonic copepods were investigated for the Southwestern Atlantic Ocean between 34 and 41°S. Our objectives were (1) to define copepod assemblages, (2) to accurately identify their association to different water masses/hydrodynamic regimes, (3) to characterize the assemblages in terms of their community structure, and (4) to test if frontal boundaries between water masses separate copepod assemblages. Biogeographic patterns were investigated using multivariate analysis (cluster and ANOSIM analyses). Biodiversity patterns were examined using different univariate indexes (point species richness and taxonomic distinctness). Five regions of similar copepod assemblages were defined for our study area each one corresponding to different environments (freshwater, estuarine, continental shelf, Malvinas and Brazil current assemblages). These assemblages have major community structure differences. In spite of the complex oceanographic scenario of our study area, that can lead us to expect a pattern of copepod communities with diffuse boundaries, we found a strong spatial correspondence between these limits and the presence of permanent frontal structures.

  16. DMSP-consuming bacteria associated with the calanoid copepod Acartia tonsa (Dana)

    DEFF Research Database (Denmark)

    Tang, K.W.; Visscher, P.T.; Dam, H.G.

    2001-01-01

    DMSP-consuming bacteria (DCB) were recovered from the body and fecal pellets of the copepod Acartia tonsa (Dana). The most probable number of DCB associated with starved A. tonsa was 9.2 X 10(2) cells copepod(-1). The abundance of DCB recovered from the copepod body increased to 1.6-2.8 X 10...

  17. Scaling of fecundity, growth and development in marine planktonic copepods

    DEFF Research Database (Denmark)

    Kiørboe, Thomas; Sabatini, M.

    1995-01-01

    We compiled information from the literature on female and egg sizes and maximum egg production, growth and developmental rates in marine planktonic copepods. While specific growth and developmental rates are invariant with body mass, weight- specific fecundity scales with female body mass(-0.......26) in both broadcast-spawning and egg-carrying copepods. Egg sizes increase with female size and, consequently, egg production rates (no. of eggs female(-1) d(-1)) are constant with size. Developmental rates were similar among egg-carrying and broadcast-spawning copepods, but the latter grow faster by 30...... to 50% and have weight-specific fecundities that are 2.5 times and egg production rates that are 7.5 times those of the former, Nauplii develop faster (by a factor of 2) but grow slower (by 20 to 40%) than copepodites in both spawning types. The main demographic implications of these findings are (1...

  18. Rapid enzymatic response to compensate UV radiation in copepods.

    Directory of Open Access Journals (Sweden)

    María Sol Souza

    Full Text Available Ultraviolet radiation (UVR causes physical damage to DNA, carboxylation of proteins and peroxidation of lipids in copepod crustaceans, ubiquitous and abundant secondary producers in most aquatic ecosystems. Copepod adaptations for long duration exposures include changes in behaviour, changes in pigmentation and ultimately changes in morphology. Adaptations to short-term exposures are little studied. Here we show that short-duration exposure to UVR causes the freshwater calanoid copepod, Eudiaptomus gracilis, to rapidly activate production of enzymes that prevent widespread collateral peroxidation (glutathione S-transferase, GST, that regulate apoptosis cell death (Caspase-3, Casp-3, and that facilitate neurotransmissions (cholinesterase-ChE. None of these enzyme systems is alone sufficient, but they act in concert to reduce the stress level of the organism. The interplay among enzymatic responses provides useful information on how organisms respond to environmental stressors acting on short time scales.

  19. Genetics of radionuclide-contaminated mosquitofish populations and homology between Gambusia affinis and G. holbrooki

    Energy Technology Data Exchange (ETDEWEB)

    Theodorakis, C.W.; Bickham, J.W. [Texas A and M Univ., College Station, TX (United States). Dept. of Wildlife and Fisheries Sciences; Elbl, T. [Univ. of Pennsylvania, Philadelphia, PA (United States). Dept. of Cell and Molecular Biology; Shugart, L.R. [L.R. Shugart and Associates, Oak Ridge, TN (United States); Chesser, R.K. [Univ. of Georgia, Aiken, SC (United States). Savannah River Ecology Lab.

    1998-10-01

    The effects of radionuclide contamination on genetic structure of eastern mosquitofish (Gambusia holbrooki) populations from the US Department of Energy`s Savannah River Site (SRS) were investigated to develop methods of assessing ecological risk of chronic exposures to xenobiotics. Fish from two contaminated and two reference sites were examined by the randomly amplified polymorphic DNA (RAPD) technique, which revealed that the frequency of three markers was greater in the contaminated than the reference sites and that the frequency of two markers was greater in reference than in the contaminated sites. A previous study examined populations of western mosquitofish (G. affinis) from the Oak Ridge National Laboratory (ORNL) and found that certain RAPD markers were present in radionuclide-contaminated ORNL populations at a higher frequency than in reference populations. The contaminant-indicative markers observed in the SRS populations were the same size and amplified by the same polymerase chain reaction primers used in the ORNL study. Southern blot analysis revealed that the SRS G. holbrooki contaminant-indicative markers were homologous to the ORNL G. affinis contaminant-indicative markers. The observation that two species show similar patterns of band frequency shifts at two separate localities is consistent with the hypothesis that these DNA markers may originate from genetic elements that provide a selective advantage in contaminated habitats. Thus, the methodology used in these studies may prove to be useful to indicate population-level effects of environmental contamination.

  20. A transcriptome derived female-specific marker from the invasive Western mosquitofish (Gambusia affinis.

    Directory of Open Access Journals (Sweden)

    Dunja K Lamatsch

    Full Text Available Sex-specific markers are a prerequisite for understanding reproductive biology, genetic factors involved in sex differences, mechanisms of sex determination, and ultimately the evolution of sex chromosomes. The Western mosquitofish, Gambusia affinis, may be considered a model species for sex-chromosome evolution, as it displays female heterogamety (ZW/ZZ, and is also ecologically interesting as a worldwide invasive species. Here, de novo RNA-sequencing on the gonads of sexually mature G. affinis was used to identify contigs that were highly transcribed in females but not in males (i.e., transcripts with ovary-specific expression. Subsequently, 129 primer pairs spanning 79 contigs were tested by PCR to identify sex-specific transcripts. Of those primer pairs, one female-specific DNA marker was identified, Sanger sequenced and subsequently validated in 115 fish. Sequence analyses revealed a high similarity between the identified sex-specific marker and the 3´ UTR of the aminomethyl transferase (amt gene of the closely related platyfish (Xiphophorus maculatus. This is the first time that RNA-seq has been used to successfully characterize a sex-specific marker in a fish species in the absence of a genome map. Additionally, the identified sex-specific marker represents one of only a handful of such markers in fishes.

  1. KARAKTERISTIK PROKSIMAT DAN KANDUNGAN SENYAWA KIMIA DAGING PUTIH DAN DAGING MERAH IKAN TONGKOL (Euthynnus affinis

    Directory of Open Access Journals (Sweden)

    H Hafiludin

    2011-04-01

    Full Text Available Indonesia has a marine biological resources are very large with the content of various types of creatures living in it. The biological richness of which are fish that have a benefit in the field of food and health. Tunafish (Euthynnus affinis is a species that is very interesting to study both in terms of nutritional composition and in terms of its economy. The purpose of this study was to determine the nutrient content and chemical compounds contained in red meat and white meat tuna. Research methodology includes observation of morphology, proximate analysis and phytochemical analysis of tuna. The highest yield was found in meat that  50%. Proximate protein content of the highest in the white meat that was 68.36%, the highest fat in red meat was 5.6%, the highest in red meat ash 3.29%, and the highest water on the white meat that was 12.16%. In the white meat and red meat tuna contained alkaloid, steroid, and carbohydrate compounds (molisch. Keywords: proximate, chemical compounds, tuna (Euthynnus affinis

  2. Copepod recruitment and food composition : Do diatoms affect hatching success?

    DEFF Research Database (Denmark)

    Jonasdottir, Sigrun; Kiørboe, Thomas

    1996-01-01

    Laboratory experiments were conducted to differentiate between factors controlling the hatching success of copepod eggs. Factors that could affect viability of eggs; viz food quality, female condition and external factors were investigated. In a series of experiments the copepod Acartia tonsa Dana...... was fed several different diets while egg production and hatching success were monitored. The diet was analysed for fatty acid content as an indicator of food quality. Both egg production and hatching were found to be affected by the nutritional quality of the food. Hatching was also highly dependent...

  3. Inbreeding depression in the partially self-incompatible endemic plant species Scalesia affinis (Asteraceae) from Galápagos islands

    DEFF Research Database (Denmark)

    Nielsen, L.R.; Siegismund, Hans Redlef; Hansen, T.

    2007-01-01

    Abstract  A previous study showed that some individuals of the tetraploid Galápagos endemic Scalesia affinis were able to produce offspring after selfing. The present study compares the fitness of self-pollinated offspring with the fitness of cross-pollinated offspring. Germination success, seedl...

  4. Distribution of NgR in the Brain of Rhinolophus affinis%NgR在中菊头蝠(Rhinolophus affinis)脑中分布

    Institute of Scientific and Technical Information of China (English)

    姚静; 鲁亚平

    2009-01-01

    Nogo和其受体相互作用可能在抑制神经再生中发挥着重要作用.运用免疫细胞化学方法,本研究观察了Nogo受体(NgR)在中菊头蝠脑中的分布.结果显示NgR在中菊头蝠脑皮层各层均有表达.在海马,NgR主要分布在CA1、CA3和DG区的神经细胞胞膜、胞质或/和突起上.杏仁核、丘脑、室旁核、视上核、视交叉上核等也有NgR阳性神经细胞着色.在脑的白质,轴突着色明显.小脑的分子层、Purkinje细胞层和颗粒细胞层均有NgR免疫阳性反应,其中阳性反应的颗粒细胞最多.这些提示NgR可能介导其配基对中菊头蝠脑多个区域的神经细胞起作用.%An interaction of Nogo with NgR has been suggested to play an important role in limiting axonal growth. By means of immunocytochemistry, the present study investigated the distribution of NgR in the brain of Rhinolophus affinis.The results showed that the NgR protein appeared to be present in all layers of the brain neocortex. In the hippocampus, NgR immunoreactivity was widely located in neurons, mainly concentrated in CA1, CA3 of the stratum pyramidale and dentate gyrus. Neurons in the amygdala, thalamus, paraventricular nucle, supraopticus and suprachiasmaticus also expressed NgR protein. The labeled neuronal cells exhibited immunoreactivity mainly in cytoplasmic membranes, cell bodies and/or neuropil. In white matter, axonal staining for NgR is prominent. In the cerebellum, immunoreactivity was detected in the molecular layer, Purkinje cell layer and granule cell layer. There were numerous granule cells and a few of Purkinje cells stained for NgR. These indicated that the NgR may mediate effects of its ligands on the neuronal cells in various brain regions of XRhinolophus affinis.

  5. Nitrogen-fixing bacteria associated with copepods in coastal waters of the North Atlantic Ocean.

    Science.gov (United States)

    Scavotto, Rosemary E; Dziallas, Claudia; Bentzon-Tilia, Mikkel; Riemann, Lasse; Moisander, Pia H

    2015-10-01

    The community composition of N2 -fixing microorganisms (diazotrophs) was investigated in copepods (primarily Acartia spp.) in parallel to that of seawater in coastal waters off Denmark (Øresund) and New England, USA. The unicellular cyanobacterial diazotroph UCYN-A was detected from seawater and full-gut copepods, suggesting that the new N contributed by UCYN-A is directly transferred to higher trophic levels in these waters. Deltaproteobacterial and Cluster 3 nifH sequences were detected in > 1 μm seawater particles and full-gut copepods, suggesting that they associate with copepods primarily via feeding. The dominant communities in starved copepods were Vibrio spp. and related Gammaproteobacteria, suggesting they represent the most permanent diazotroph associations in the copepods. N2 fixation rates were up to 3.02 pmol N copepod(-1) day(-1). Although at a typical copepod density in estuarine waters, these volumetric rates are low; considering the small size of a copepod, these mesozooplanktonic crustaceans may serve as hotspots of N2 fixation, at 12.9-71.9 μmol N dm(-3) copepod biomass day(-1). Taken together, diazotroph associations range from more permanent attachments to copepod feeding on some groups. Similar diazotroph groups detected on the eastern and western Atlantic Ocean suggest that these associations are a general phenomenon and play a role in the coastal N cycles. © 2015 Society for Applied Microbiology and John Wiley & Sons Ltd.

  6. Detecting in situ copepod diet diversity using molecular technique: development of a copepod/symbiotic ciliate-excluding eukaryote-inclusive PCR protocol.

    Directory of Open Access Journals (Sweden)

    Simin Hu

    Full Text Available Knowledge of in situ copepod diet diversity is crucial for accurately describing pelagic food web structure but is challenging to achieve due to lack of an easily applicable methodology. To enable analysis with whole copepod-derived DNAs, we developed a copepod-excluding 18S rDNA-based PCR protocol. Although it is effective in depressing amplification of copepod 18S rDNA, its applicability to detect diverse eukaryotes in both mono- and mixed-species has not been demonstrated. Besides, the protocol suffers from the problem that sequences from symbiotic ciliates are overrepresented in the retrieved 18S rDNA libraries. In this study, we designed a blocking primer to make a combined primer set (copepod/symbiotic ciliate-excluding eukaryote-common: CEEC to depress PCR amplification of symbiotic ciliate sequences while maximizing the range of eukaryotes amplified. We firstly examined the specificity and efficacy of CEEC by PCR-amplifying DNAs from 16 copepod species, 37 representative organisms that are potential prey of copepods and a natural microplankton sample, and then evaluated the efficiency in reconstructing diet composition by detecting the food of both lab-reared and field-collected copepods. Our results showed that the CEEC primer set can successfully amplify 18S rDNA from a wide range of isolated species and mixed-species samples while depressing amplification of that from copepod and targeted symbiotic ciliate, indicating the universality of CEEC in specifically detecting prey of copepods. All the predetermined food offered to copepods in the laboratory were successfully retrieved, suggesting that the CEEC-based protocol can accurately reconstruct the diets of copepods without interference of copepods and their associated ciliates present in the DNA samples. Our initial application to analyzing the food composition of field-collected copepods uncovered diverse prey species, including those currently known, and those that are unsuspected

  7. Detecting in situ copepod diet diversity using molecular technique: development of a copepod/symbiotic ciliate-excluding eukaryote-inclusive PCR protocol.

    Science.gov (United States)

    Hu, Simin; Guo, Zhiling; Li, Tao; Carpenter, Edward J; Liu, Sheng; Lin, Senjie

    2014-01-01

    Knowledge of in situ copepod diet diversity is crucial for accurately describing pelagic food web structure but is challenging to achieve due to lack of an easily applicable methodology. To enable analysis with whole copepod-derived DNAs, we developed a copepod-excluding 18S rDNA-based PCR protocol. Although it is effective in depressing amplification of copepod 18S rDNA, its applicability to detect diverse eukaryotes in both mono- and mixed-species has not been demonstrated. Besides, the protocol suffers from the problem that sequences from symbiotic ciliates are overrepresented in the retrieved 18S rDNA libraries. In this study, we designed a blocking primer to make a combined primer set (copepod/symbiotic ciliate-excluding eukaryote-common: CEEC) to depress PCR amplification of symbiotic ciliate sequences while maximizing the range of eukaryotes amplified. We firstly examined the specificity and efficacy of CEEC by PCR-amplifying DNAs from 16 copepod species, 37 representative organisms that are potential prey of copepods and a natural microplankton sample, and then evaluated the efficiency in reconstructing diet composition by detecting the food of both lab-reared and field-collected copepods. Our results showed that the CEEC primer set can successfully amplify 18S rDNA from a wide range of isolated species and mixed-species samples while depressing amplification of that from copepod and targeted symbiotic ciliate, indicating the universality of CEEC in specifically detecting prey of copepods. All the predetermined food offered to copepods in the laboratory were successfully retrieved, suggesting that the CEEC-based protocol can accurately reconstruct the diets of copepods without interference of copepods and their associated ciliates present in the DNA samples. Our initial application to analyzing the food composition of field-collected copepods uncovered diverse prey species, including those currently known, and those that are unsuspected, as copepod prey

  8. Copepod guts as biogeochemical hotspots in the sea

    DEFF Research Database (Denmark)

    Tang, Kam W.; Glud, Ronnie N.; Glud, Anni;

    2011-01-01

    , with a steep gradient from the anal opening to the metasome region. The central metasome region was completely anoxic. Food remains in the gut led to a lower oxygen level, and a diatom diet induced a stronger oxygen gradient than a cryptophyte diet. The acidic and suboxic–anoxic environments of the copepod gut...

  9. Prey perception in feeding-current feeding copepods

    DEFF Research Database (Denmark)

    Kiørboe, Thomas; Goncalves, Rodrigo J.; Florian Couespel, Damien

    2016-01-01

    We reply to the comments of Paffenhöfer and Jiang () who argues that remote chemical prey perception is necessary for feeding-current feeding copepods to fulfill their nutritional requirements in a dilute ocean, that remote chemical prey detection may only be observed at very low prey concentrati...

  10. Linkage between copepods and bacteria in the North Atlantic Ocean

    NARCIS (Netherlands)

    De Corte, D.; Lekunberri, I.; Sintes, E.; Garcia, J.A.L.; Gonzalez, S.; Herndl, G.J.

    2014-01-01

    Copepods and bacteria are fundamental components of the pelagic food web andplay a major role in biogeochemical cycles. Marine bacteria have a free-living or particleattachedlifestyle, but as members of the microbial food web, the only biotic interaction of bacteriais commonly assumed to be with

  11. Propagation of planktonic copepods: production and mortality of eggs

    DEFF Research Database (Denmark)

    Kiørboe, Thomas; Møhlenberg, Flemming; Tiselius, Peter

    1988-01-01

    Data on fecundity and egg mortality of neritic copepods were collected in various seasons, areas and under various hydrographical conditions. On a seasonal basis variations in fecundity (F) were related to temperature rather than to the abundance of phytoplankton (P). However, a strong correlatio...

  12. The copepod Calanus spp. (Calanidae) is repelled by polarized light.

    Science.gov (United States)

    Lerner, Amit; Browman, Howard I

    2016-10-20

    Both attraction and repulsion from linearly polarized light have been observed in zooplankton. A dichotomous choice experiment, consisting of plankton light traps deployed in natural waters at a depth of 30 m that projected either polarized or unpolarized light of the same intensity, was used to test the hypothesis that the North Atlantic copepod, Calanus spp., is linearly polarotactic. In addition, the transparency of these copepods, as they might be seen by polarization insensitive vs. sensitive visual systems, was measured. Calanus spp. exhibited negative polarotaxis with a preference ratio of 1.9:1. Their transparency decreased from 80% to 20% to 30% in the unpolarized, partially polarized, and electric (e-) vector orientation domains respectively - that is, these copepods would appear opaque and conspicuous to a polarization-sensitive viewer looking at them under conditions rich in polarized light. Since the only difference between the two plankton traps was the polarization cue, we conclude that Calanus spp. are polarization sensitive and exhibit negative polarotaxis at low light intensities (albeit well within the sensitivity range reported for copepods). We hypothesize that Calanus spp. can use polarization vision to reduce their risk of predation by polarization-sensitive predators and suggest that this be tested in future experiments.

  13. The copepod Calanus spp. (Calanidae) is repelled by polarized light

    Science.gov (United States)

    Lerner, Amit; Browman, Howard I.

    2016-10-01

    Both attraction and repulsion from linearly polarized light have been observed in zooplankton. A dichotomous choice experiment, consisting of plankton light traps deployed in natural waters at a depth of 30 m that projected either polarized or unpolarized light of the same intensity, was used to test the hypothesis that the North Atlantic copepod, Calanus spp., is linearly polarotactic. In addition, the transparency of these copepods, as they might be seen by polarization insensitive vs. sensitive visual systems, was measured. Calanus spp. exhibited negative polarotaxis with a preference ratio of 1.9:1. Their transparency decreased from 80% to 20% to 30% in the unpolarized, partially polarized, and electric (e-) vector orientation domains respectively - that is, these copepods would appear opaque and conspicuous to a polarization-sensitive viewer looking at them under conditions rich in polarized light. Since the only difference between the two plankton traps was the polarization cue, we conclude that Calanus spp. are polarization sensitive and exhibit negative polarotaxis at low light intensities (albeit well within the sensitivity range reported for copepods). We hypothesize that Calanus spp. can use polarization vision to reduce their risk of predation by polarization-sensitive predators and suggest that this be tested in future experiments.

  14. Copepod guts as biogeochemical hotspots in the sea

    DEFF Research Database (Denmark)

    Tang, Kam W.; Glud, Ronnie N.; Glud, Anni

    2011-01-01

    The environmental conditions inside the gut of Calanus hyperboreus and C. glacialis were measured with microelectrodes. An acidic potential hydrogen (pH) gradient was present in the gut of C. hyperboreus, and the lowest pH recorded was 5.40. The gut pH of a starved copepod decreased by 0.53 after...

  15. Copepod carcasses as microbial hot spots for pelagic denitrification

    DEFF Research Database (Denmark)

    Glud, Ronnie N.; Grossart, Hans-Peter; Larsen, Morten

    2015-01-01

    Copepods are exposed to a high non-predatory mortality and their decomposing carcasses act as microniches with intensified microbial activity. Sinking carcasses could thereby represent anoxic microenvironment sustaining anaerobic microbial pathways in otherwise oxic water columns. Using non-invas...

  16. Macroevolutionary patterns of sexual size dimorphism in copepods

    DEFF Research Database (Denmark)

    Hirst, Andrew G.; Kiørboe, Thomas

    2014-01-01

    , and their female-biased SSD is greater than in many free-living families. However, other parasitic copepods which do not appear to have obvious differences in sex-based mate searching risks also show similar or even more extreme SSD, therefore suggesting other factors can drive the observed extremes....

  17. Linkage between copepods and bacteria in the North Atlantic Ocean

    NARCIS (Netherlands)

    De Corte, D.; Lekunberri, I.; Sintes, E.; Garcia, J.A.L.; Gonzalez, S.; Herndl, G.J.

    2014-01-01

    Copepods and bacteria are fundamental components of the pelagic food web andplay a major role in biogeochemical cycles. Marine bacteria have a free-living or particleattachedlifestyle, but as members of the microbial food web, the only biotic interaction of bacteriais commonly assumed to be with the

  18. Copepod feeding currents : flow patterns, filtration rates and energetics

    NARCIS (Netherlands)

    van Duren, LA; Stamhuis, EJ; Videler, JJ

    2003-01-01

    Particle image velocimetry was used to construct a quasi 3-dimensional image of the flow generated by the feeding appendages of the calanoid copepod Temora longicornis. By scanning layers of flow, detailed information was obtained on flow velocity and velocity gradients. The flow around feeding T. l

  19. Cyclopoid copepods (Lichomolgidae) from octocorals at Eniwetok Atoll

    NARCIS (Netherlands)

    Humes, Arthur G.

    1973-01-01

    This report of lichomolgid copepods found for the first time associated with octocorals in the Pacific Ocean includes six species, two of them new. Paramolgus eniwetokensis n. sp. and Paramolgus ostentus n. sp. are associated with Lobophytum pauciflorum (Ehrenberg). New host records include Acanthom

  20. Copepod swarm in the Campbell Bay (Andaman Sea)

    Digital Repository Service at National Institute of Oceanography (India)

    Goswami, S.C.; Rao, T.S.S.

    During the 68th cruise of R.V.Gaveshani, an unusual abundance of calanoid copepods of family Pontellidae was observed in the Campbell Bay (lat.6 degrees 30'-6 degrees 59'N and long 93 degrees 56'-94 degrees 15'E) Swarm density (25974 to 138420/m 3...

  1. IDENTIFIKASI BAKTERI DARI IKAN TONGKOL (Euthynnus affinis YANG DIPERDAGANGKAN DI PASAR IKAN KEDONGANAN BALI

    Directory of Open Access Journals (Sweden)

    Gusti Ayu Dianti Violentina

    2016-06-01

    Full Text Available Ikan tongkol (Euthynnus affinis merupakan ikan konsumsi yang disukai masyarakat.Pengetahuan tentang bakteri yang ditemukan pada tubuh ikan ini sangat penting untuk tujuan kesehatan masyarakat dan kajian biologi ikan.  Penelitian ini bertujuan untuk mengidentifikasi bakteri yang berasosiasi dengan ikan tersebut.Bakteri dari usus ikan diambil secara aseptis dan ditumbuhkan pada Blood Agar dan Nutrient Broth. DNA total dari kultur agar cair diisolasi dengan chelax, gen 16S RNA diamplifikasi dengan PCR menggunakan primer universal dengan produk sekitar 1300 bp. Produk PCR dirunut dengan metode Big-Dye termination. Hasilnya disepadankan dan dianalisis dengan MEGA 6.0. Pada penelitian ini, 14 spesies bakteri yang memiliki > 99% kesamaan dengan data GenBankteridentifikasi, yaitu Photobacterium leiognathi, Uruburuella testudinis, Aeromonas molluscorum, Psychrobacter celer, Psychrobacer faecalis, Acinetobacter johnsonii, Vibrio gallicus, Bacillus megaterium, Vagococcus fessus, Shewanella baltica, Shewanella algae, Rothia nasimurium, Myroides phaeus dan Yersinia ruckeri. Peran bakteribakteri tersebut dalam biologi ikan dan kesehatan masyarakat perlu dikaji lebih lanjut.

  2. Fecundity of the Hypostomus affinis (Siluriformes, Loricariidae) in the Lajes Reservoir, Rio de Janeiro, Brazil.

    Science.gov (United States)

    Duarte, Silvana; Araújo, Francisco Gerson

    2002-03-01

    The armored catfish Hypostomus affinis is a widespread Loricariidae fish in the Lajes Reservoir (22 degrees 42'-22 degrees 50' S; 43 degrees 53'-44 degrees 05' W), the largest lentic environment in the Rio de Janeiro State, but little is known about their reproductive biology. One hundred and twenty five females, captured from January 1996 to December 1997, were used to assess ovarian development (29 were used to determine fecundity). The oocyte distribution by size-diameter classes revealed the occurrence of two modes suggesting an asynchronic development of the ovaries. The total fecundity ranged from 1235 to 4304, averaging 2374. An exponential relationship between fecundity and total length was determined, and a direct linear relationship was found between fecundity and total weight and gonad weight.

  3. Polar constituents, protection against reactive oxygen species, and nutritional value of Chinese artichoke (Stachys affinis Bunge).

    Science.gov (United States)

    Venditti, Alessandro; Frezza, Claudio; Celona, Diana; Bianco, Armandodoriano; Serafini, Mauro; Cianfaglione, Kevin; Fiorini, Dennis; Ferraro, Stefano; Maggi, Filippo; Lizzi, Anna Rita; Celenza, Giuseppe

    2017-04-15

    In the present work, we studied the chemical composition of Chinese artichoke (S. affinis tubers) by analyzing its polar constituents and its macro- and micro- nutrients. A total of nine compounds were isolated from the tuber ethanolic extract and structurally elucidated by Nuclear Magnetic Resonance (NMR) spectroscopy and mass spectrometry (MS). The marker compounds identified were oligosaccharide stachyose and the organic acid, succinic acid, as well as phenylethanoid and iridoid glycosides. The macronutrient profile was dominated by carbohydrates (36.9% dw), whereas potassium (2.36%) was the most abundant micro-nutrient. The tuber ethanolic extract was able to efficiently protect human cells (Caco-2, SHSY-5Y and K562) against t-BHP-induced oxidative damage.

  4. Bamboo (Neosinocalamus affinis)-based thin film, a novel biomass material with high performances.

    Science.gov (United States)

    Song, Fei; Xu, Chen; Bao, Wen-Yi; Wang, Xiu-Li; Wang, Yu-Zhong

    2015-03-30

    Exploration of biomass based materials to replace conventional petroleum based ones has been a trend in recent decades. In this work, bamboo (Neosinocalamus affinis) with abundant resources was used for the first time to prepare films in the presence of cellulose. The effects of weight ratio of bamboo/cellulose on the appearances and properties of the films were investigated. It was confirmed there existed strong interactions between bamboo and cellulose, which were favorable to formation of homogeneous structure of blend films. Particularly, the presence of bamboo could improve the surface hydrophobicity, water resistance and thermal stability of blend films, and the films possessed an excellent oxygen barrier property, compared with generally used commercial packaging films. The bamboo biomass, therefore, is successfully used to create a new film material with a good application prospect in the fields of packaging, coating, and food industry.

  5. Development and characterization of microsatellite markers of the eastern keelback mullet (Liza affinis).

    Science.gov (United States)

    Liu, L; Gao, T X; Han, Z Q; Li, C H; Sun, D R; Song, N

    2016-06-17

    Twenty-four polymorphic microsatellite loci were isolated and characterized for Liza affinis using a (GT)13-enriched genomic library. The number of alleles per locus ranged from 3 to 9, with a mean number of 6.250. The observed and expected heterozygosities ranged from 0.417 to 1.000 and from 0.550 to 0.861, with an average of 0.859 and 0.779, respectively. Deviation from Hardy-Weinberg proportions was detected at three loci. Evidence of null alleles was found at two loci. These markers will be useful in further studies investigating the genetic variation and population structure of this species, and may provide insights into the maintenance and efficient management of eastern keelback mullet resources.

  6. Microbiome disruption and recovery in the fish Gambusia affinis following exposure to broad-spectrum antibiotic

    Directory of Open Access Journals (Sweden)

    Carlson JM

    2017-05-01

    Full Text Available Jeanette M Carlson,1 Annie B Leonard,1 Embriette R Hyde,2,3 Joseph F Petrosino,2,3 Todd P Primm1 1Department of Biological Sciences, Sam Houston State University, Huntsville, 2Alkek Center for Metagenomics and Microbiome Research, 3Integrative Molecular and Biomedical Sciences Training Program, Department of Molecular Virology & Microbiology, Baylor College of Medicine, Houston, TX, USA Abstract: Antibiotics are a relatively common disturbance to the normal microbiota of humans and agricultural animals, sometimes resulting in severe side effects such as antibiotic-associated enterocolitis. Gambusia affinis was used as a vertebrate model for effects of a broad-spectrum antibiotic, rifampicin, on the skin and gut mucosal microbiomes. The fish were exposed to the antibiotic in the water column for 1 week, and then monitored during recovery. As observed via culture, viable counts from the skin microbiome dropped strongly yet returned to pretreatment levels by 1.6 days and became >70% resistant. The gut microbiome counts dropped and took longer to recover (2.6 days, and became >90% drug resistant. The resistance persisted at ~20% of skin counts in the absence of antibiotic selection for 2 weeks. A community biochemical analysis measuring the presence/absence of 31 activities observed a 39% change in results after 3 days of antibiotic treatment. The antibiotic lowered the skin and gut microbiome community diversity and altered taxonomic composition, observed by 16S rRNA profiling. A 1-week recovery period did not return diversity or composition to pretreatment levels. The genus Myroides dominated both the microbiomes during the treatment, but was not stable and declined in abundance over time during recovery. Rifampicin selected for members of the family Comamonadaceae in the skin but not the gut microbiome. Consistent with other studies, this tractable animal model shows lasting effects on mucosal microbiomes following antibiotic exposure, including

  7. Using Gambusia affinis growth and condition to assess estuarine habitat quality: A comparison of indices

    Science.gov (United States)

    Piazza, Bryan P.; La Peyre, M.K.

    2010-01-01

    Numerous indices have been used to estimate fish growth and condition however, differences in sensitivity and reliability of the methods have hampered efforts to identify appropriate indicators for routine evaluation of habitat quality in the field. We compared common morphometric (length, weight, somatic growth, length-weight condition) and biochemical (RNA:DNA ratio, relative DNA content, energy density) growth indices on the same wild-caught mosquitofish Gambusia affinis to examine their usefulness as indicators of habitat quality. A laboratory experiment was used to quantify growth rates of wild-caught G. affinis under different feeding treatments. Field studies consisted of both a short-term enclosure experiment (10 d) and weekly (7 wk) fish collections to compare growth indices in managed inflow and reference marshes during a winter/spring freshwater pulse event in upper Breton Sound, Louisiana, USA. Marshes flooded by restored freshwater pulses were capable of producing optimum growth (0.001 g DW d-1 DW = dry weight) and energetically valuable habitat (>6000 cal g-1 DW) for trophic transport. Because of differences in timing of response, morphometric and biochemical indices were generally not directly correlated, but there was clear agreement in direction and magnitude of response. The most striking difference in timing was that biochemical indices (RNA:DNA) responded more slowly to treatments than did morphometric growth indices. While gross patterns are comparable between indicators, differences in sensitivity and response time between indicators suggest that choice of indicator needs to be accounted for in interpretation and analysis of effects. ?? Inter-Research 2010, www.int-res.com.

  8. DESCRIPCIÓN MORFOLÓGICA DEL TUBO DIGESTIVO DE JUVENILES DE RUBIO Salminus affinis (PISCES: CHARACIDAE Alimentary tract of juvenile Rubio Salminus affinis (Pisces: Characidae morphological description

    Directory of Open Access Journals (Sweden)

    VJ ATENCIO GARCÍA

    Full Text Available El objetivo del estudio fue la descripción del tubo digestivo de juveniles de Rubio Salminus affinis. Se analizaron cinco juveniles con 23,6±2,6 cm de longitud total y 142,8±62,5 g de peso. Se realizó descripción topográfica y morfológica de los órganos y cortes histológicos con tinción H-E. El esófago es un órgano tubular corto de pared gruesa que representa el 7,8% de la longitud total del tubo digestivo, presenta pliegues internos que ofrecen gran capacidad de distensión permitiendo el paso de presas de gran tamaño. El estómago es una bolsa asimétrica en forma de "Y", grande y musculosa, amplio en la porción anterior y estrecho hacia el fondo; el número de ciegos pilóricos varió entre 13 y 23 pudiendo ser monotubulares y ramificados. El intestino, con tres asas, se extiende desde el esfínter pilórico hasta el ano. Histológicamente el tubo digestivo está formado por cuatro capas: mucosa, submucosa, muscular y serosa; el epitelio de revestimiento del esófago es estratificado plano no queratinizado con células caliciformes, cambiando a simple cilíndrico mucosecretor llegando al estómago; en el estómago se encuentra epitelio simple cilíndrico mucosecretor y los ciegos pilóricos e intestino son revestidos por epitelio simple cilíndrico con células caliciformes. Tanto el valor promedio del coeficiente intestinal (0,58, como la pared distensible del estómago sugieren que el Rubio tiene un tubo digestivo propio de carnívoro y sus características histológicas presentan similitud con la mayoría de vertebrados superiores.The aim of work was giving biological information about Salminus affinis,a morphological description of the alimentary tract was carried out. Five juvenile Rubio were analyzed (23.6±2.6 cm of total length and 142.8±62.5 g of weight. Topographical and morphological description organs and histology with H-E stain were carried out. The esophagus is a short tubular thick-walled organ that represents 7

  9. Acute toxicity effects of cadmium on Gambusia affinis%镉对食蚊鱼(Gambusia affinis)的急性毒性效应

    Institute of Scientific and Technical Information of China (English)

    刘阳; 陈曦; 覃剑晖

    2015-01-01

    以食蚊鱼(Gambusia affinis)为受试生物,采用半静水式急性毒性试验和亚急性毒性试验,分别测定Cd2+对食蚊鱼的半致死质量浓度(LC50)和超氧化物歧化酶(SOD)活性、过氧化氢酶(CAT)活性、谷胱甘肽转硫酶(GST)活性及组织结构变化,检测镉对食蚊鱼的毒性作用,以探讨Cd2+在水环境中的毒性及食蚊鱼在环境科学研究中的应用.结果表明,Cd2+对食蚊鱼96 h的LC50为22.55 mg/L,属于高毒物质.相同Cd2+暴露质量浓度下,随暴露时间延长,SOD和CAT活性总体表现为先升高后降低的趋势,GST活性则总体表现为先升高后降低、且趋于稳定的趋势.Cd2+暴露后食蚊鱼肝和鳃组织会出现不同程度损伤.研究表明,Cd2+对食蚊鱼属于高毒物质,验证了食蚊鱼对化学品Cd2+的敏感性.

  10. Dieta e comportamento de forrageamento de Suiriri affinis e S. islerorum (Aves, Tyrannidae em um cerrado do Brasil central Diet and foraging behavior of Suiriri affinis and S. islerorum (Aves, Tyrannidae in a central Brazilian cerrado

    Directory of Open Access Journals (Sweden)

    Leonardo E. Lopes

    2005-12-01

    Full Text Available Foi estudado o comportamento de forrageamento de Suiriri affinis (suiriri-do-cerrado e S. islerorum (suiriri-da-chapada, duas espécies de Tyrannidae que ocorrem em sintopia nos cerrados do Brasil central. Durante o ano de 2003 foram registradas 188 observações de forrageamento para S. affinis e 150 para S. islerorum. Foram encontradas diferenças significativas entre as duas espécies em relação à altura e substrato de forrageamento, fitofisionomia utilizada e densidade da folhagem no local do ataque. O comportamento e a direção do ataque, a espécie de planta e a distância de vôo não diferiram entre as espécies. A análise de 26 conteúdos estomacais de membros do gênero revelou o consumo exclusivo de artrópodes. A baixa porcentagem de observações de forrageamento direcionadas a frutos (apenas 7% e 9%, respectivamente confirmou o caráter insetívoro do gênero.The foraging behavior of Suiriri affinis (Campo Suiriri and S. islerorum (Chapada Flycatcher, two sintopic Tyrant Flycatchers in the Central Brazilian Cerrado (tropical savanna was studied. During 2003, 188 feeding bouts of S. affinis and 150 of S. islerorum were registered. Differences between the two species in the feeding height, foraging substrate, phytophysiognomy used, and foliage density at the point of foraging observation were found. The attack methods, attack direction, distance of flight, and plant species used did not differ between both species. The analysis of 26 stomach contents of members of this genus revealed only arthropods. The low percentage of feeding bouts directed to fruits (only 7% and 9%, respectively confirmed the insectivorous character of this genus.

  11. Defecation of dimethylsulfoniopropionate (DMSP) by the copepod Acartia tonsa as functions of ambient food concentration and body DMSP content

    DEFF Research Database (Denmark)

    Tang, K.W.

    2001-01-01

    The dimethylsulfoniopropionate (DMSP) defecation rate of Acartia tonsa (calanoid copepod)feeding on Tetraselmis impellucida (prasinophyte) was correlated with food concentration and copepod body DMSP content. Copepod fecal pellets represent a highly concentrated source of DMSP and thus play an im...... an important role in DMSP flux and microbial processes in the ocean.......The dimethylsulfoniopropionate (DMSP) defecation rate of Acartia tonsa (calanoid copepod)feeding on Tetraselmis impellucida (prasinophyte) was correlated with food concentration and copepod body DMSP content. Copepod fecal pellets represent a highly concentrated source of DMSP and thus play...

  12. DMSP-consuming bacteria associated with the calanoid copepod Acartia tonsa (Dana)

    DEFF Research Database (Denmark)

    Tang, K.W.; Visscher, P.T.; Dam, H.G.

    2001-01-01

    DMSP-consuming bacteria (DCB) were recovered from the body and fecal pellets of the copepod Acartia tonsa (Dana). The most probable number of DCB associated with starved A. tonsa was 9.2 X 10(2) cells copepod(-1). The abundance of DCB recovered from the copepod body increased to 1.6-2.8 X 10(4) a...... Elsevier Science B.V. All rights reserved....

  13. Host-specific and pH-dependent microbiomes of copepods in an extensive rearing system

    DEFF Research Database (Denmark)

    Skovgaard, Alf; Castro Mejia, Josue Leonardo; Hansen, Lars Hestbjerg

    2015-01-01

    gradient gel electrophoresis (DGGE) analysis, a clear difference was found between the microbiomes of the two copepod species, Acartia tonsa and Centropages hamatus, present in the system. This pattern was corroborated through 454/FLX-based 16S rRNA gene amplicon sequencing of copepod microbiomes, which...... furthermore showed that the abiotic parameters pH and oxygen concentration in rearing tank water were the key factors influencing composition of copepod microbiomes....

  14. Distribution of Arctic and Pacific copepods and their habitat in the northern Bering and Chukchi seas

    Science.gov (United States)

    Sasaki, Hiroko; Matsuno, Kohei; Fujiwara, Amane; Onuka, Misaki; Yamaguchi, Atsushi; Ueno, Hiromichi; Watanuki, Yutaka; Kikuchi, Takashi

    2016-08-01

    The advection of warm Pacific water and the reduction in sea ice in the western Arctic Ocean may influence the abundance and distribution of copepods, a key component of food webs. To quantify the factors affecting the abundance of copepods in the northern Bering and Chukchi seas, we constructed habitat models explaining the spatial patterns of large and small Arctic and Pacific copepods separately. Copepods were sampled using NORPAC (North Pacific Standard) nets. The structures of water masses indexed by principle component analysis scores, satellite-derived timing of sea ice retreat, bottom depth and chlorophyll a concentration were integrated into generalized additive models as explanatory variables. The adequate models for all copepods exhibited clear continuous relationships between the abundance of copepods and the indexed water masses. Large Arctic copepods were abundant at stations where the bottom layer was saline; however they were scarce at stations where warm fresh water formed the upper layer. Small Arctic copepods were abundant at stations where the upper layer was warm and saline and the bottom layer was cold and highly saline. In contrast, Pacific copepods were abundant at stations where the Pacific-origin water mass was predominant (i.e. a warm, saline upper layer and saline and a highly saline bottom layer). All copepod groups showed a positive relationship with early sea ice retreat. Early sea ice retreat has been reported to initiate spring blooms in open water, allowing copepods to utilize more food while maintaining their high activity in warm water without sea ice and cold water. This finding indicates that early sea ice retreat has positive effects on the abundance of all copepod groups in the northern Bering and Chukchi seas, suggesting a change from a pelagic-benthic-type ecosystem to a pelagic-pelagic type.

  15. Host-specific and pH-dependent microbiomes of copepods in an extensive rearing system

    DEFF Research Database (Denmark)

    Skovgaard, Alf; Castro Mejia, Josue Leonardo; Hansen, Lars Hestbjerg;

    2015-01-01

    gradient gel electrophoresis (DGGE) analysis, a clear difference was found between the microbiomes of the two copepod species, Acartia tonsa and Centropages hamatus, present in the system. This pattern was corroborated through 454/FLX-based 16S rRNA gene amplicon sequencing of copepod microbiomes, which...... furthermore showed that the abiotic parameters pH and oxygen concentration in rearing tank water were the key factors influencing composition of copepod microbiomes....

  16. Metabolic responses to metal pollution in shrimp Crangon affinis from the sites along the Laizhou Bay in the Bohai Sea.

    Science.gov (United States)

    Xu, Lanlan; Ji, Chenglong; Zhao, Jianmin; Wu, Huifeng

    2016-12-15

    Marine environment in the Laizhou Bay is potentially contaminated by metals from industrial discharges. In this study, metal concentrations in shrimps Crangon affinis indicated that two typical sites (S6283 and S5283) close to Longkou and Zhaoyuan cities along the Laizhou Bay have been contaminated by metals, including Cd, As, Cu, Ni, Co, and Mn. In particular, Cd and As were the main metal contaminants in S6283. In S5283, however, Cu was the most important metal contaminant. The metabolic responses in the shrimps indicated that the metal pollution in S6283 and S5283 induced disturbances in osmotic regulation and energy metabolism and reduced anaerobiosis, lipid metabolism, and muscle movement. However, alteration in the levels of dimethylglycine, dimethylamine, arginine, betaine, and glutamine indicated that the metal pollution in S5283 induced osmotic stress through different pathways compared to that in S6283. In addition, dimethylamine might be the biomarker of Cu in shrimp C. affinis.

  17. Recent Discovery of Widespread Ixodes affinis (Acari: Ixodidae) Distribution in North Carolina With Implications for Lyme Disease Studies

    Science.gov (United States)

    2010-06-01

    implications for Lyme disease studies Bruce A. Harrison1, Walker H. Rayburn Jr.2, Marcee Toliver1, Eugene E. Powell1, Barry R. Engber1, Lance A. Durden3...affinis is morphologically very similar to Ixodes scapularis Say, the primary vector of Lyme disease borreliae in the eastern U.S.A. (Keirans et al. 1996...Ixodidae) distribution in North Carolina with implications for Lyme disease studies 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER

  18. Proximate composition and mineral and fatty acid profiles of male and female jinga shrimps (Metapenaeus affinis, H. Milne Edwards, 1837)

    OpenAIRE

    DİNÇER, Mehmet Tolga; İlker AYDIN

    2014-01-01

    The jinga shrimp (Metapenaeus affinis, H. Milne Edwards, 1837) is a commercially valuable alien decapod and a seafood product that is highly popular at seafood restaurants in İzmir (Turkey). The chemical, mineral, and fatty acid compositions of male and female jinga shrimps harvested in the Mediterranean Sea were determined for the first time. The compositions of both sexes confirmed that the jinga shrimp is a healthy food source due to its balance of nutrients, with efficient levels of prote...

  19. Decline in biodiversity of copepods in coastal waters of Mumbai

    Digital Repository Service at National Institute of Oceanography (India)

    Stephen, R.; Jayalakshmy, K.V.; Nair, V.R.

    and diversity of copepods increased in Makupa creek, Mombasa where dumping of domestic and industrial waste was rampant. ]2'49'E s.e: s.r N + O.S 1.0 1.S .N, KAMATHH' 4 •• •N, KHIM .DP .N, o· o· .M, .M, CUNDERI oM, 0' 42' .5, .5, .5, 41' 1 N '70 7S 80 ss Fig. 1... per day (mId) of industrial waste. The projected daily domestic waste water flow for greater Mumbai for 1985 and 2005 are respectively 1350 and 2000 mid. Copepods were studied during pre-monsoon and post-monsoon periods along with relevant water...

  20. Host-Specific and pH-Dependent Microbiomes of Copepods in an Extensive Rearing System.

    Directory of Open Access Journals (Sweden)

    Alf Skovgaard

    Full Text Available Copepods are to an increasing extent cultivated as feed for mariculture fish larvae with variable production success. In the temperate climate zone, this production faces seasonal limitation due to changing abiotic factors, in particular temperature and light. Furthermore, the production of copepods may be influenced by biotic factors of the culture systems, such as competing microorganisms, harmful algae, or other eukaryotes and prokaryotes that may be non-beneficial for the copepods. In this study, the composition of bacteria associated with copepods was investigated in an extensive outdoor copepod production system. Light microscopy and scanning electron microscopy revealed that bacteria were primarily found attached to the exoskeleton of copepods although a few bacteria were also found in the gut as well as internally in skeletal muscle tissue. Through 16S rRNA gene-targeted denaturing gradient gel electrophoresis (DGGE analysis, a clear difference was found between the microbiomes of the two copepod species, Acartia tonsa and Centropages hamatus, present in the system. This pattern was corroborated through 454/FLX-based 16S rRNA gene amplicon sequencing of copepod microbiomes, which furthermore showed that the abiotic parameters pH and oxygen concentration in rearing tank water were the key factors influencing composition of copepod microbiomes.

  1. Geographic differences in the carapace shape of the crab Cyrtograpsus affinis (Decapoda: Varunidae and its taxonomic implications

    Directory of Open Access Journals (Sweden)

    Aníbal H. Lezcano

    2011-11-01

    Full Text Available Cyrtograpsus genus was traditionally considered to be composed of three species: C. angulatus, C. altimanus and C. affinis. However, recent studies have found solid evidence suggesting that C. affinis and C. altimanus belong to a single species and hypothesize that the morphological differences which caused this misclassification could be related to different ecophenotypes or life stages. Here we report a geometric morphometrics study on the carapace shape of Cyrtograpsus specimens from the Río de la Plata estuary (36°S and the Nuevo Gulf (42.75°S, testing for shape differences between different sizes (allometry in the two environments. We found that previous morphological descriptions of the two species were associated with different sizes of a continuous, statistically significant allometric shape variation, concluding that C. affinis is a junior synonym of C. altimanus. We also found significant differences in the carapace shape between estuarine and marine environments, suggesting an effect of the environmental variables on carapace shape and a potential adaptive value of this trait.

  2. Contrasting ecosystem-effects of morphologically similar copepods.

    Directory of Open Access Journals (Sweden)

    Blake Matthews

    Full Text Available Organisms alter the biotic and abiotic conditions of ecosystems. They can modulate the availability of resources to other species (ecosystem engineering and shape selection pressures on other organisms (niche construction. Very little is known about how the engineering effects of organisms vary among and within species, and, as a result, the ecosystem consequences of species diversification and phenotypic evolution are poorly understood. Here, using a common gardening experiment, we test whether morphologically similar species and populations of Diaptomidae copepods (Leptodiaptomus ashlandi, Hesperodiaptomus franciscanus, Skistodiaptomus oregonensis have similar or different effects on the structure and function of freshwater ecosystems. We found that copepod species had contrasting effects on algal biomass, ammonium concentrations, and sedimentation rates, and that copepod populations had contrasting effects on prokaryote abundance, sedimentation rates, and gross primary productivity. The average size of ecosystem-effect contrasts between species was similar to those between populations, and was comparable to those between fish species and populations measured in previous common gardening experiments. Our results suggest that subtle morphological variation among and within species can cause multifarious and divergent ecosystem-effects. We conclude that using morphological trait variation to assess the functional similarity of organisms may underestimate the importance of species and population diversity for ecosystem functioning.

  3. ESTIMASI PARAMETER POPULASI IKAN TONGKOL KOMO (Euthynnus affinis DI PERAIRAN LAUT JAWA

    Directory of Open Access Journals (Sweden)

    Umi Chodrijah

    2016-03-01

    Full Text Available Tongkol komo (Euthynnus affinis yang dikenal dengan nama perdagangan kawa-kawa termasuk dalam family Scombridae. Sebagai ikan pelagis mereka membentuk gerombolan, perenang cepat dan pemakan daging (carnivore. Penelitian tentang estimasi parameter populasi ikan tongkol komo di Laut Jawa didasarkan pada pengumpulan data di Pelabuhan Perikanan Nusantara Pekalongan, pada bulan Februari-Desember 2012. Analisis parameter populasi menggunakan program “Electronic Length Frequency Analysis (ELEFAN-1. Hasil penelitian menunjukkan sebaran frekuensi panjang cagak ikan tongkol komo selama penelitian diperoleh panjang minimum 11,7 cm FL, panjang maksimum 55,4 cmFL dan panjang-rata-rata 34,1 cm. Persamaan dari hubungan panjang dan bobot ikan tongkol komo adalah W=0,00001L3,1267 (r2=0,986. Parameter populasi menunjukkan panjang asimtotik (L∞ = 59,63 cm, kecepatan pertumbuhan ikan tongkol (K =  0,91 per tahun dan umur pada saat ditetaskan (t0  = 0,178 tahun. Mortalitas total (Z adalah 2,64 per tahun dengan mortalitas alami (M dan mortalitas penangkapan (F masing-masing 1,13/tahun dan  1,51/tahun. Rasio eksploitasi ikan tongkol adalah 0,57 pertahun. Hal ini berarti bahwa pemanfaatan ikan tongkol komo di Laut Jawa sudah dimanfaatkan secara penuh (fully exploited. As pelagic fish, kawa-kawa (Euthynnus affinis were included in the family Scombridae, Schooling behaviours, fast swimmers and carnivore. Research on population parameter estimates of kawa-kawa of the Java Sea conducted in the Pekalongan fishing port during February to December 2012. Data analyzed using analytical model application with program of “Electronic Length Frequency Analysis (ELEFAN -1”. The results showed that the frequency distribution of fish during sampling periods ranged of 11.7 cm FL to 55.4 cmFL with average length of 34.1 cmFL. Equation of a length and weight relationship of W = 0.00001 L3, 1267 (r2 = 0.986. Population parameters included asymptotic length growth rate (L∞ was

  4. Analysis of the parasitic copepod species richness among Mediterranean fish

    Science.gov (United States)

    Raibaut, André; Combes, Claude; Benoit, Françoise

    1998-06-01

    The Mediterranean ichthyofauna is composed of 652 species belonging to 405 genera and 117 families. Among these, 182 were studied for their parasitic copepods. The analysis of all the works conducted on these crustacea yielded 226 species distributed in 88 genera and 20 families. For each fish species we have established a file providing the species name of the fish, its family, its geographical distribution within the Mediterranean and some of its bio-ecological characteristics. Within each file, all the parasitic copepod species reported on each host species were listed. This allowed to know the species richness (SR) of these hosts. We thus produced 182 files within which 226 copepod species are distributed. A program was created under the Hypercard software, in order to analyse our data. Two parameters were studied. The first one is the mean species richness (MSR), which corresponds to the mean of the different SR found on the different host species. The second is the parasite-host ratio (P/H), which is the ratio of the number of copepod species by the number of host species. These parameters are calculated by our program for all the 182 species of Mediterranean fishes retained in our investigation, on the first hand, and, on the second hand, for one particular group of fish species. We used the following variables to investigate their correlations with copepod species richness: taxonomy—fish families, genera and species; biometry—maximal size of the adult fish; eco-ethology—mode of life (benthic, pelagic or nectonic), displacements (sedentary, migratory with environmental change, or migratory without environmental change), behaviour (solitary or gregarious). Other variables (colour, food, reproduction, abundance, distribution area) were also analysed but did not reveal any clear correlation. Providing that our study does not rely on quantitative (prevalence, intensity) but qualitative basis our aim was only to reveal some tendencies. These tendencies are

  5. Effects of mosquitofish (Gambusia affinis cues on wood frog (Lithobates sylvaticus tadpole activity

    Directory of Open Access Journals (Sweden)

    Katherine F. Buttermore

    2011-06-01

    Full Text Available We examined the changes in activity of wood frog (Lithobates sylvaticus tadpoles exposed to combinations of visual, chemical, and mechanical cues of the invasive mosquitofish (Gambusia affinis. We also examined whether the responses of the tadpoles to the predator cues were influenced by the short-term accumulation of chemical cues in the experimental container. In our experiment, the activity of wood frog (L. sylvaticus tadpoles was not affected by the presence of various cues from mosquitofish. Our experiment demonstrated that the repeated use of trial water can influence the activity level of tadpoles, regardless of the predator cue treatment used. Tadpoles in the first trial tended to be less active than tadpoles in subsequent trials. This effect does not appear to be mediated by the accumulation of predator cues since there was no significant interaction term. Our results suggest that short-term accumulation of predator chemical cues do not affect the behavior of wood frog tadpoles: however, our results suggest that the repeated use of the same water in consecutive trials may affect tadpole behavior, perhaps through the accumulation of conspecific chemical cues.

  6. Development of mosquitofish (Gambusia affinis holbrooki populations in lentic mesocosms. Perspectives for ecotoxicological studies

    Directory of Open Access Journals (Sweden)

    DREZE V.

    1998-07-01

    Full Text Available In the perspective of ecotoxicological assays in mesocosms, the development of mosquitofish populations (Gambusia affinis holbrooki has been assessed. The objective was to evaluate the ability of fish to reproduce in these experimental ponds under the climatic conditions of Brittany, and to see if population size and individual criteria were related to the number of adults initially introduced. Six mesocosms (3.2 m diameter and 0.7 m water depth similarly designed received sexually mature mosquitofish at the rate of 12 (6 females and 6 males, 6 (3 females and 3 males and 2 (1 female and 1 male in June 1996. Each assay was duplicated. In December 1996, the entire populations were collected and the weight, size and sex of the individuals were noted. Length-frequency distributions were relatively similar between mesocosms and the different mode groups showed that the reproductive activity occurred until the beginning of fall. The produced biomass (from 4.1 to 38.3 g and number of fish collected (from 26 to 301 were statistically correlated to the number of pairs initially introduced. This study provides interesting perspectives for ecotoxicological investigations in which the effects of pollutants on mosquitofish would be assessed at the population level.

  7. Hepatic element concentrations of lesser scaup (aythya affinis) during spring migration in the upper midwest

    Science.gov (United States)

    Pillatzki, A.E.; Neiger, R.D.; Chipps, S.R.; Higgins, K.F.; Thiex, N.; Afton, A.D.

    2011-01-01

    High concentrations of some hepatic elements might be contributing to the decline of the continental lesser scaup (Aythya affinis) population. We evaluated hepatic element concentrations of male and female lesser scaup collected from the upper Midwest (Iowa, Minnesota, North Dakota, and South Dakota) during the 2003 and 2004 spring migrations. We measured concentrations of 24 elements in livers of 117 lesser scaup. We found that only selenium concentrations were at levels (>3.0 ??g/g wet weight [ww)]) proposed to adversely affect reproduction. Approximately 49% of females (n = 61) had individual hepatic concentrations >3.0 ??g/g ww selenium (Se). Our observed hepatic concentration of Se was similar to that reported in lesser scaup collected from the mid-continental United States but less than Se concentrations reported from the Great Lakes region. We found that the liver cadmium (Cd) concentration for males was significantly higher than that for females. Gender differences in hepatic Cd concentrations have not been previously reported for lesser scaup, but Cd is known to have negative impacts on male reproduction. Our results indicate that lesser scaup migrating through the upper Midwest in spring have elevated Se levels and that males carry a significantly greater Cd burden than females. Moreover, elemental concentrations might be high enough to affect reproduction in both male and female lesser scaup, but controlled laboratory studies are needed to adequately assess the effects of Se and Cd on lesser scaup reproduction. ?? 2010 Springer Science+Business Media, LLC.

  8. Masculinization and reproductive effects in western mosquitofish (Gambusia affinis) after long-term exposure to androstenedione.

    Science.gov (United States)

    Hou, Li-Ping; Yang, Yang; Shu, Hu; Ying, Guang-Guo; Zhao, Jian-Liang; Fang, Gui-Zhen; Xin, Li; Shi, Wen-Jun; Yao, Li; Cheng, Xue-Mei

    2017-09-12

    Androstenedione (AED) is a naturally occurring steroid hormone. It is metabolized to potent androgens, which may induce androgenic effects in fish. However, little is known whether and how the androgens interfere with the fish gonadal development and reproduction. This study aimed at demonstrating the effects of long-term AED exposure on reproduction and development in mosquitofish (Gambusia affinis). The growth, development and several morphological endpoints, including the segment number and length of anal fin, histological changes of gonads and liver, were evaluated in mosquitofish during development from fertilized embryo to adulthood (180 days) after exposure of AED at environmentally relevant concentrations. We found that the growth (length, body weight and condition factor) of fish was negatively correlated with AED concentration in females, but not in males. The significant elongation of the ray and increment of segment numbers in the anal fin, were detected in all mosquitofish after exposure. Moreover, AED exposure (0.4gµ/L) caused damages in gonads and reduced the number of pregnant females. These findings indicate that AED has adverse effects on the growth and development of the western mosquitofish after long-term exposure (180d). Long-term exposure (180d) to AED, including environmentally relevant concentration (0.4µg/L and 4µg/L), induced masculinization in female mosquitofish under the experimental conditions. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. Feminization and masculinization of western mosquitofish (Gambusia affinis) observed in rivers impacted by municipal wastewaters

    Science.gov (United States)

    Huang, Guo-Yong; Liu, You-Sheng; Chen, Xiao-Wen; Liang, Yan-Qiu; Liu, Shuang-Shuang; Yang, Yuan-Yuan; Hu, Li-Xin; Shi, Wen-Jun; Tian, Fei; Zhao, Jian-Liang; Chen, Jun; Ying, Guang-Guo

    2016-02-01

    Municipal wastewaters have been known to contain various estrogens and androgens. Little is known about the joint action of these chemicals from wastewaters on fishes in the aquatic environment. The objectives of this study were to investigate the estrogenic and/or androgenic effects in wild mosquitofish (Gambusia affinis) of two effluent-impacted rivers in South China by determining morphological changes and hepatic mRNA expression levels of relevant genes such as vitellogenin (Vtg), estrogen receptor (ERα) and androgen receptors (ARα and ARβ), and to assess the linkages of those morphological changes and hepatic mRNA expression levels to the chemical concentrations measured by in vitro bioassays and chemical analysis. The results showed a significant induction of Vtg and ERα mRNA in the livers of the males and a gonopodium-like anal fin in the females collected at the majority of sites. Redundancy analysis and Pearson correlation analysis showed that the chemical concentrations obtained by in vitro bioassays and chemical analysis had significant correlations with some of the endpoints for the estrogenic and/or androgenic effects in mosquitofish. The findings from this study indicate that the estrogens and androgens present in the two rivers could cause the observed estrogenic and androgenic effects in mosquitofish.

  10. Hepatic element concentrations of lesser scaup (Aythya affinis) during spring migration in the upper Midwest.

    Science.gov (United States)

    Pillatzki, Angela E; Neiger, Regg D; Chipps, Steven R; Higgins, Kenneth F; Thiex, Nancy; Afton, Alan D

    2011-07-01

    High concentrations of some hepatic elements might be contributing to the decline of the continental lesser scaup (Aythya affinis) population. We evaluated hepatic element concentrations of male and female lesser scaup collected from the upper Midwest (Iowa, Minnesota, North Dakota, and South Dakota) during the 2003 and 2004 spring migrations. We measured concentrations of 24 elements in livers of 117 lesser scaup. We found that only selenium concentrations were at levels (>3.0 μg/g wet weight [ww)]) proposed to adversely affect reproduction. Approximately 49% of females (n = 61) had individual hepatic concentrations >3.0 μg/g ww selenium (Se). Our observed hepatic concentration of Se was similar to that reported in lesser scaup collected from the mid-continental United States but less than Se concentrations reported from the Great Lakes region. We found that the liver cadmium (Cd) concentration for males was significantly higher than that for females. Gender differences in hepatic Cd concentrations have not been previously reported for lesser scaup, but Cd is known to have negative impacts on male reproduction. Our results indicate that lesser scaup migrating through the upper Midwest in spring have elevated Se levels and that males carry a significantly greater Cd burden than females. Moreover, elemental concentrations might be high enough to affect reproduction in both male and female lesser scaup, but controlled laboratory studies are needed to adequately assess the effects of Se and Cd on lesser scaup reproduction.

  11. Endogenous contributions to egg protein formation in lesser scaup Aythya affinis

    Science.gov (United States)

    Cutting, Kyle A.; Hobson, Keith A.; Rotella, Jay J.; Warren, Jeffrey M.; Wainwright-de la Cruz, Susan E.; Takekawa, John Y.

    2011-01-01

    Lesser scaup Aythya affinis populations have declined throughout the North American continent for the last three decades. It has been hypothesized that the loss and degradation of staging habitats has resulted in reduced female body condition on the breeding grounds and a concomitant decline in productivity. We explored the importance of body (endogenous) reserves obtained prior to arrival on the breeding ground in egg protein formation in southwestern Montana during 2006–2008 using stable-carbon (δ13C) and nitrogen (δ15N) isotope analyses of scaup egg components, female tissue, and local prey items. From arrival on the breeding grounds through the egg-laying period, δ15N values of scaup red blood cells decreased while δ13C values became less variable; a pattern consistent with endogenous tissues equilibrating with local (freshwater) dietary sources. In 2006 and 2008, isotopic values for egg albumen and yolk protein indicated that most (>90%) protein used to produce these components was obtained on the breeding grounds. However, in 2007, a year with an exceptionally warm and dry spring, endogenous reserves contributed on average 41% of yolk and 29% of albumen. Results from this study suggest that female scaup can meet the protein needs of egg production largely from local dietary food sources. This highlights the importance of providing high-quality breeding habitats for scaup. Whether this pattern holds in areas with similar breeding season lengths but longer migration routes, such as those found in the western boreal forest, should be investigated.

  12. Parasites and diseases in marine copepods: Challenges for future mass-production of live feed for fish larva production

    DEFF Research Database (Denmark)

    Skovgaard, Alf

    Copepods are the natural food for many marine fish larvae, and the use of cultured copepods as life feed is, therefore, becoming increasingly important as more marine fish species are being produced in aquaculture. Large-scale cultivation of copepods may be challenged by diseases and parasites...

  13. Recommended feeding regime and light climate in live feed cultures of the calanoid copepod Acartia tonsa Dana

    DEFF Research Database (Denmark)

    Jepsen, Per Meyer; Steensbjerg Bjørbæk, Niels; Rayner, Thomas Allan

    2017-01-01

    Understanding and optimising the parameters that controls the success for copepod cultures are the foundation for large scaled copepod cultures. Many underlying copepod culture parameters are already quantified and comprehended, but there is a lack in knowledge of optimising feeding regimes for c...

  14. Sensory capabilities and food capture of two small copepods, Paracalanus parvus and Pseudocalanus sp

    DEFF Research Database (Denmark)

    Tiselius, Peter; Saiz, Enric; Kiørboe, Thomas

    2013-01-01

    Detection, handling, and selection of prey are key features of suspension-feeding copepods. Using high-speed video, we determined detection distances and durations of all elements of the food gathering process in two small calanoid copepods, Paracalanus parvus and Pseudocalanus sp. Animals were f...

  15. Copepod egg production, moulting and growth rates and secondary production in the Skagerrak in August 1988

    DEFF Research Database (Denmark)

    Peterson, W.T.; Tiselius, P.; Kiørboe, Thomas

    1991-01-01

    Measurements of hydrography, chlorophyll, moulting rates of juvenile copepods and egg production rates of adult female copepods were made at eight stations along a transect across the Skagerrak. The goals of the study were to determine (i) if there were correlations between spatial variations in ...

  16. Perceiving the algae: How feeding-current feeding copepods detect their nonmotile prey

    DEFF Research Database (Denmark)

    Goncalves, Rodrigo J.; Kiørboe, Thomas

    2015-01-01

    Feeding-current feeding copepods detect and capture prey individually, but the mechanism by which nonmotile prey is detected has been unclear. Early reports that copepods detect phytoplankton prey at distances of one body length or more led to the hypothesis that solutes leaking from the prey wou...

  17. Do inactivated Microbial Preparations Improve Life History Traits of the Copepod Acartia tonsa?

    DEFF Research Database (Denmark)

    Drillet, Guillaume; Rabarimanantsoa, Tahina; Frouel, Stéphane

    2011-01-01

    production and hatching success, HS). This was carried out because the use of copepods as live prey in aquaculture could increase the number of fish successfully raised through their entire life cycle. However, the availability of copepods is limited by their difficulty to be effectively raised. Our results...

  18. Consequences of acclimation to Microcystis on the selective feeding behavior of the calanoid copepod Eudiaptomus gracilis

    NARCIS (Netherlands)

    Ger, K.A.; Panosso, R.; Lürling, M.F.L.L.W.

    2011-01-01

    We tested the hypothesis that calanoid copepods would adapt to extended periods of Microcystis exposure by increasing selective feeding on alternative food. Copepod (Eudiaptomus gracilis) clearance rates were compared before and after a 5-d acclimation to Microcystis aeruginosa using paired food mix

  19. Recirculating aquaculture system for high density production of the calanoid copepod Acartia tonsa (Dana)

    DEFF Research Database (Denmark)

    Vu, Minh Thi Thuy; Øie, Gunvor; Reinertsen, Helge

    The calanoid copepod Acartia tonsa (Dana) is one of the most promising copepod species for marine larviculture. This species has a wide tolerance to temperature and salinity, small size, can produce resting eggs. All their nauplii, copepodites and adults can be use as excellent feeds for marine f...

  20. Recirculating aquaculture system for high density production of the calanoid copepod Acartia tonsa (Dana)

    DEFF Research Database (Denmark)

    Vu, Minh Thi Thuy; Øie, Gunvor; Reinertsen, Helge

    2013-01-01

    The calanoid copepod Acartia tonsa (Dana) is one of the most promising copepod species for marine larviculture. This species has a wide tolerance to temperature and salinity, small size, can produce resting eggs. All their nauplii, copepodites and adults can be use as excellent feeds for marine...

  1. Different microbiomes associated with the copepods Acartia tonsa and Temora longicornis from the same marine environment

    DEFF Research Database (Denmark)

    Dorosz, Julia; Castro-Mejia, Josue Leonardo; Hansen, Lars Hestbjerg

    2016-01-01

    Microbiomes of the neritic copepod species Acartia tonsa and Temora longicornis collected in coastal Danish waters were investigated by use of 16S rRNA gene-Amplicon highthroughput sequencing. In contrast to current assumptions and findings, microbiomes of the 2 copepod species from the same envi...

  2. Probability Models for the Distribution of Copepods in Different Coastal Ecosystems Along the Straits of Malacca

    Science.gov (United States)

    Matias-Peralta, Hazel Monica; Ghodsi, Alireza; Shitan, Mahendran; Yusoff, Fatimah Md.

    Copepods are the most abundant microcrustaceans in the marine waters and are the major food resource for many commercial fish species. In addition, changes in the distribution and population composition of copepods may also serve as an indicator of global climate changes. Therefore, it is important to model the copepod distribution in different ecosystems. Copepod samples were collected from three different ecosystems (seagrass area, cage aquaculture area and coastal waters off shrimp aquaculture farm) along the coastal waters of the Malacca Straits over a one year period. In this study the major statistical analysis consisted of fitting different probability models. This paper highlights the fitting of probability distributions and discusses the adequateness of the fitted models. The usefulness of these fitted models would enable one to make probability statements about the distribution of copepods in three different ecosystems.

  3. Active prey selection in two pelagic copepods feeding on potentially toxic and non-toxic dinoflagellates

    DEFF Research Database (Denmark)

    Schultz, Mette; Kiørboe, Thomas

    2009-01-01

    Grazing on two red tide dinoflagellates, the potentially toxic Karenia mikimotoi and the non-toxic Gyrodinium instriatum, was examined in two species of marine copepods, Pseudocalanus elongatus and Temora longicornis. Both copepods cleared K. mikimotoi at rates that were a little lower but compar......Grazing on two red tide dinoflagellates, the potentially toxic Karenia mikimotoi and the non-toxic Gyrodinium instriatum, was examined in two species of marine copepods, Pseudocalanus elongatus and Temora longicornis. Both copepods cleared K. mikimotoi at rates that were a little lower...... but comparable to those at which they cleared the slightly larger G. instriatum when the two dinoflagellates were offered separately. However, when feeding on mixtures of the two prey species, the clearance rates on K. mikimotoi were substantially reduced in both copepods while their clearances of G. instiatum...

  4. Structural and functional responses of harpacticoid copepods to anoxia in the Northern Adriatic: an experimental approach

    Directory of Open Access Journals (Sweden)

    M. De Troch

    2013-02-01

    Full Text Available Combined in situ and laboratory studies were conducted to document the effects of anoxia on the structure and functioning of meiobenthic communities, with special focus on harpacticoid copepods. In a first step, anoxia was created artificially by means of an underwater chamber at 24 m depth in the Northern Adriatic, Gulf of Trieste (Mediterranean. Nematodes were found as most abundant taxon, followed by harpacticoid copepods. While nematode densities were not affected by treatment (anoxia/normoxia or sediment depth, these factors had a significant impact on copepod abundances. Harpacticoid copepod family diversity, in contrast, was not affected by anoxic conditions, only by depth. Ectinosomatidae and Cletodidae were most abundant in both normoxic and anoxic samples. The functional response of harpacticoid copepods to anoxia was studied in a laboratory tracer experiment by adding 13C pre-labelled diatoms to sediment cores in order to test (1 if there is a difference in food uptake by copepods under normoxic and anoxic conditions and (2 whether initial (normoxia feeding of harpacticoid copepods on diatoms results in a better survival of copepods in subsequent anoxic conditions. Independent of the addition of diatoms, there was a higher survival rate in normoxia than anoxia. The supply of additional food did not result in a higher survival rate of copepods in anoxia, which might be explained by the presence of a nutritionally better food source and/or a lack of starvation before adding the diatoms. However, there was a reduced grazing pressure by copepods on diatoms in anoxic conditions. This resulted in a modified fatty acid composition of the sediment. We concluded that anoxia not only impacts the survival of consumers (direct effect but also of primary producers (indirect effect, with important implications for the recovery phase.

  5. Structural and functional responses of harpacticoid copepods to anoxia in the Northern Adriatic: an experimental approach

    Directory of Open Access Journals (Sweden)

    M. De Troch

    2013-06-01

    Full Text Available Combined in situ and laboratory studies were conducted to document the effects of anoxia on the structure and functioning of meiobenthic communities, with special focus on harpacticoid copepods. In a first step, anoxia was created artificially by means of an underwater chamber at 24 m depth in the Northern Adriatic, Gulf of Trieste (Mediterranean. Nematodes were found as the most abundant taxon, followed by harpacticoid copepods. While nematode densities were not affected by treatment (anoxia/normoxia or sediment depth, these factors had a significant impact on copepod abundances. Harpacticoid copepod family diversity, in contrast, was not affected by anoxic conditions, only by depth. Ectinosomatidae and Cletodidae were most abundant in both normoxic and anoxic samples. The functional response of harpacticoid copepods to anoxia was studied in a laboratory tracer experiment by adding 13C pre-labelled diatoms to sediment cores in order to test (1 if there is a difference in food uptake by copepods under normoxic and anoxic conditions and (2 whether initial (normoxia feeding of harpacticoid copepods on diatoms results in a better survival of copepods in subsequent anoxic conditions. Independent of the addition of diatoms, there was a higher survival rate in normoxia than anoxia. The supply of additional food did not result in a higher survival rate of copepods in anoxia, which might be explained by the presence of a nutritionally better food source and/or a lack of starvation before adding the diatoms. However, there was a reduced grazing pressure by copepods on diatoms in anoxic conditions. This resulted in a modified fatty acid composition of the sediment. We concluded that anoxia not only impacts the survival of consumers (direct effect but also of primary producers (indirect effect, with important implications for the recovery phase.

  6. Structural and functional responses of harpacticoid copepods to anoxia in the Northern Adriatic: an experimental approach

    Science.gov (United States)

    De Troch, M.; Roelofs, M.; Riedel, B.; Grego, M.

    2013-06-01

    Combined in situ and laboratory studies were conducted to document the effects of anoxia on the structure and functioning of meiobenthic communities, with special focus on harpacticoid copepods. In a first step, anoxia was created artificially by means of an underwater chamber at 24 m depth in the Northern Adriatic, Gulf of Trieste (Mediterranean). Nematodes were found as the most abundant taxon, followed by harpacticoid copepods. While nematode densities were not affected by treatment (anoxia/normoxia) or sediment depth, these factors had a significant impact on copepod abundances. Harpacticoid copepod family diversity, in contrast, was not affected by anoxic conditions, only by depth. Ectinosomatidae and Cletodidae were most abundant in both normoxic and anoxic samples. The functional response of harpacticoid copepods to anoxia was studied in a laboratory tracer experiment by adding 13C pre-labelled diatoms to sediment cores in order to test (1) if there is a difference in food uptake by copepods under normoxic and anoxic conditions and (2) whether initial (normoxia) feeding of harpacticoid copepods on diatoms results in a better survival of copepods in subsequent anoxic conditions. Independent of the addition of diatoms, there was a higher survival rate in normoxia than anoxia. The supply of additional food did not result in a higher survival rate of copepods in anoxia, which might be explained by the presence of a nutritionally better food source and/or a lack of starvation before adding the diatoms. However, there was a reduced grazing pressure by copepods on diatoms in anoxic conditions. This resulted in a modified fatty acid composition of the sediment. We concluded that anoxia not only impacts the survival of consumers (direct effect) but also of primary producers (indirect effect), with important implications for the recovery phase.

  7. Astaxanthin production in marine pelagic copepods grazing on two different phytoplankton diets

    Science.gov (United States)

    Van Nieuwerburgh, Lies; Wänstrand, Ingrid; Liu, Jianguo; Snoeijs, Pauli

    2005-02-01

    The red carotenoid astaxanthin is a powerful natural antioxidant of great importance in aquatic food webs where it is abundant in eggs and body tissues of fish and crustaceans. Little is known about the impact of the phytoplankton diet on astaxanthin production in copepods, its major pelagic producers. We followed the transfer of carotenoids from phytoplankton to copepods in a mesocosm experiment on the northern Atlantic coast (Norway) and recorded the astaxanthin production in copepods. Wild copepods grazed on nutrient-manipulated phytoplankton blooms, which differed in community composition and nutrient status (nitrogen or silicate limitation). The copepod pigments consisted mainly of free astaxanthin and mono- and diesters of astaxanthin. We found no significant difference in astaxanthin production per copepod individual or per unit C depending on the phytoplankton community. However, in the mesocosms astaxanthin per unit C decreased compared with natural levels, probably through a lower demand for photoprotection by the copepods in the dense phytoplankton blooms. The total astaxanthin production per litre was higher in the silicate-limited mesocosms through increased copepod density. Pigment ratio comparisons suggested that the copepod diet here consisted more of diatoms than in the nitrogen-limited mesocosms. Silicate-saturated diatoms were less grazed, possibly because they could invest more in defence mechanisms against their predators. Our study suggests that the production of astaxanthin in aquatic systems can be affected by changes in nutrient dynamics mediated by phytoplankton community composition and copepod population growth. This bottom-up force may have implications for antioxidant protection at higher trophic levels in the food web.

  8. Copepod feeding study in the upper layer of the tropical South China Sea

    Science.gov (United States)

    Tseng, Li-Chun; Dahms, Hans-Uwe; Chen, Qing-Chao; Hwang, Jiang-Shiou

    2009-12-01

    The South China Sea (SCS) is the world’s largest marginal sea being notable for vertical mixing at various scales resulting in a sequence of chemical and biological dynamics in surface waters. We investigated the ingestion, gut content, evacuation and clearance rates of copepods collected from six stations (including a South East Asia Time Series station) along a transect line in the tropical of a SCS cruise during September 27, 1999 to October 2, 1999. The goal of the present study was to understand the feeding ecology of copepods in the upper water layers (0-5 m) of the northern SCS during autumn. We measured the gut pigment contents of 33 copepod species by the gut fluorescence method. The gut chlorophyll a values of most small size copepods (danae (7.07 ng Chl a individual-1). The gut pigment contents of 33 copepod species (including 70 samples and 1,290 individuals) estimated is negatively correlated with seawater temperature (Pearson correlation r = -0.292, P = 0.014) and is positively correlated with the chlorophyll a concentration of ambient waters (Pearson correlation r = 0.243, P = 0.043). Mean gut pigment content, ingestion and clearance rates (from 80 samples and 1,468 individuals) show that larger copepods (>2 mm) had significantly higher values than medium sized copepods (1-2 mm) and smaller sized copepods. The present study shows that the performance of feeding on phytoplankton was variable in different sized copepod groups, suggesting that copepods obtained in the tropical area of the southeastern Taiwan Strait might be opportunistic feeders.

  9. Identificação de Paspalum notatum fluegge e Axonopus affinis chase através da análise de fragmentos foliares Identification of Paspalum notatum fluegge and Axonopus affinis chase through leaf fragments analysis

    Directory of Open Access Journals (Sweden)

    Maria Cláudia Lopes Nogueira

    1999-03-01

    Full Text Available Este trabalho teve como objetivo a caracterização e identificação de fragmentos foliares de Paspalum notatum Fluegge e Axonopus affinis Chase, como forma de subsidiar projetos de avaliação da dieta de animais fistulados. Para a caracterização das espécies, foram feitas várias coletas de folhas em áreas de pastagem natural do Campus da Universidade Federal de Santa Maria (RS, de maio de 1992 a junho de 1993. A diferenciação das espécies foi baseada no padrão de nervação, presença de pêlos e características do ápice e bordo foliar, observadas com auxílio de estereomicroscópio. A habilidade de um observador em identificar fragmentos das duas espécies numa mistura e a eficácia dos descritores foliares mencionados foram testadas através de análise estatística. Desta forma, foi constatado que o padrão de nervação é o melhor critério de diferenciação e que A. affinis difere de P. notatum, basicamente, pelo ápice foliar obtuso e pela presença de nervuras quaternárias. A análise estatística confirmou a capacidade do observador em reconhecer fragmentos das duas espécies.This research aimed at the characterization and identification of leaves, fragments of Paspalum notatum Fluegge and Axonopus affinis Chase, for future studies of diet evaluation of fistuleted animals. For the species characterization, several collections of leaves were made in native pasture areas at the UFSM Campus (Santa Maria, RS from May, 1992 to June, 1993. The differentiation of the species was based on the leave’s venation pattern, hair presence, leaf border and apex features, observed with a stereomicroscope. The obverver’s ability to identify the two species of leaves in a misture were tested with statistical analysis. It was observed that the venation pattern is the best characterization criteria and that A. affinis differs from P. notatum mainly by the obtuse leaf apex and by the quaternary vein presence. The statistical analysis

  10. Fluctuación poblacional de Xyleborus ferrugineus y X. affinis (Coleoptera: Curculionidae) en ecosistemas de Tabasco, México Population fluctuation of Xyleborus ferrugineus and X. affinis (Coleoptera: Curculionidae) in ecosystems of Tabasco, Mexico

    OpenAIRE

    Ricardo Rangel; Manuel Pérez; Saúl Sánchez; Silvia Capello

    2012-01-01

    Los Scolytinae son insectos comúnmente conocidos como coleópteros descortezadores o ambrosiales debido a su forma de alimentarse. Existen especies que restringen su actividad reproductiva a una planta huésped o a un número reducido de ellas, otras son altamente polífagas. Se estudiaron las poblaciones de Scolytinae con el objetivo de conocer la fluctuación poblacional de X. ferrugineus y X. affinis en ecosistemas de Tabasco, México durante noviembre 2010-julio 2011, febrero 2010-enero 2011 y ...

  11. Coprophagy in copepods and in a natural zooplankton community

    DEFF Research Database (Denmark)

    Poulsen, Louise K.; Kiørboe, Thomas

    Sediment trap studies have revealed that often only a minor fraction of the zooplankton fecal pellet production leave the upper ocean, and it has been suggested that copepod grazing on pellets (coprophagy) is the reason for this. A simple model is here used to estimate rate of coprophagy from lab...... 5 % of the fecal pellet production in the upper 50 m was lost as flux below 50 m depth. Estimates of coprophagy rates showed, however, that the zooplankton community > 200 um could account for only a few percent of the fecal pellet loss. Thus, plankton organisms

  12. Effects of Ration Levels on Growth and Reproduction from Larvae to First-Time Spawning in the Female Gambusia affinis

    Directory of Open Access Journals (Sweden)

    Zhiming Zhu

    2015-03-01

    Full Text Available Somatic growth and reproduction were examined in individual laboratory-grown female Gambusia affinis fed with high (H, medium (M and low (L ration levels from birth to the first-time spawning. Results showed that the body length and weight, condition factor (CF, wet weight gain (WGw, specific growth rate in wet weight (SGRw and ration levels in terms of energy (RLe decreased significantly (p < 0.05 with decreasing ration levels from birth to first-time spawning. On the contrary, the food conversion efficiency in terms of energy (FCEe increased significantly (p < 0.05 with the decreasing ration levels from birth to first-time sexual maturity. Furthermore, higher percentages of energy intake from food were allocated to somatic and gonad growth in M and L groups compared to the H group before sexual maturity; In addition, the time for first-time spawning in groups M and L was longer than that of the H group. As a result, the gonad-somatic index (GSI and oocytes/embryos weight in M and L groups were similar to that of the H group, although the ovary weight and oocytes/embryos numbers were all lower than that of the H group. Also, similar growth performances were observed in second-generation offspring, which were produced by female parents fed with different ration levels. These findings suggest that the female G. affinis could produce a number of healthy offspring under conditions of food restriction, and that this could be achieved by increasing the energy allocated to gonad development, reducing fecundity and delaying spawning time. These life strategies ensured that G. affinis could survive and thrive in adverse environmental conditions and exhibit characteristics of invasive fish species.

  13. Comparison of mosquito control provided by the arroyo chub (Gila orcutti) and the mosquitofish (Gambusia affinis).

    Science.gov (United States)

    Van Dam, Alex R; Walton, William E

    2007-12-01

    Two 6-wk trials were conducted in 28-m2 earthen ponds to compare the efficacy of the arroyo chub, Gila orcutti, to the mosquitofish, Gambusia affinis, as a biological control agent for mosquitoes and a possible replacement for the mosquitofish in sensitive watersheds of southern California. The mosquitofish population growth rate was 1.73 times greater than the arroyo chub population growth rate; however, greater reproduction by the mosquitofish did not result in significantly better reduction of mosquitoes than was provided by the comparatively small populations of arroyo chub. On average across a 6-wk study in the spring, both larvivorous fishes reduced the abundance of 3rd and 4th instars by 4- to 5-fold compared to that observed in the control ponds that lacked fish but contained few invertebrate predators. The abundance of nontarget microinvertebrates in ponds containing the mosquitofish was only 7% of that in ponds containing the arroyo chub during the summer, but did not differ significantly between the fish species treatments when zooplankton was comparatively more abundant during the spring. Even though the number of individuals produced by each fish species during 6 wk in the spring was greater than for fish stocked in the summer, species-specific population growth rates in the spring study (individuals/individual/d; mosquitofish, 0.077; arroyo chub, 0.044) were only slightly higher than in the summer (individuals/individual/d; mosquitofish, 0.068; arroyo chub, 0.039) indicating that differences in the number of fish stocked contributed primarily to the differences in final population size between spring and summer studies. The arroyo chub is native to the South Coastal drainages in California and should be considered as a viable alternative to the mosquitofish for integrated mosquito management programs in riverine wetlands and sensitive watersheds of southern California.

  14. Historical introgression and the persistence of ghost alleles in the intermediate horseshoe bat (Rhinolophus affinis).

    Science.gov (United States)

    Mao, Xiuguang; He, Guimei; Hua, Panyu; Jones, Gareth; Zhang, Shuyi; Rossiter, Stephen J

    2013-02-01

    Phylogenetic conflicts between genetic markers can help to disentangle complex histories of phylogeography and introgression among taxa. We previously proposed that the Chinese mainland subspecies of the intermediate horseshoe bat Rhinolophus affinis himalayanus colonized Hainan Island to form the subspecies R. a. hainanus. Subsequent recolonization of the mainland formed a third taxon, R. a macrurus, and a secondary contact zone with the ancestral himalayanus. To test for historical and recurrent genetic exchange between these mainland subspecies, we sampled populations of each from two parapatric zones and undertook analyses using one mtDNA marker, three nuclear genes and 14 microsatellites. Nuclear DNA, echolocation call frequencies and morphological data all recovered two taxa; however, a mtDNA phylogeny revealed two himalayanus clades, of which one clustered with macrurus, as well as some shared or related mtDNA haplotypes in eastern populations. Isolation-with-migration (IM) models suggested some mtDNA gene flow from macrurus to himalayanus. However, strong population structure in himalayanus raises the possibility that macrurus captured mtDNA from a coastal population of himalayanus that has since become rare or extinct. To reconcile these two sets of results, we suggest that the IM estimates might reflect historical mtDNA gene flow among populations of himalayanus, before mtDNA was subsequently captured by macrurus. Finally, microsatellite-based ABC analyses supported the island origin of macrurus; however, mtDNA-based ABC analyses suggest this taxon might have evolved on the mainland. Our findings highlight the importance of understanding population history and structure for interpreting hybridization and introgression events. © 2012 Blackwell Publishing Ltd.

  15. Tracking the movements of a post-nesting Southern River Terrapin (Batagur affinis edwardmolli)

    Science.gov (United States)

    Chen, Pelf-Nyok; Wong, Adrian

    2015-09-01

    A Southern River Terrapin (Batagur affinis edwardmolli) Conservation Project was initiated on one terrapin nesting bank in 2011, following the discovery of a River Terrapin population in the Kemaman River, Terengganu in 2010. Since this project was initiated, Turtle Conservation Society of Malaysia (TCS) was instrumental in the gazettement of three nesting banks along the Kemaman River, from which all River Terrapin eggs are collected for incubation. However, there are at least a dozen other "unprotected" nesting banks along the river, where all eggs were collected for human consumption. This project attempted to determine the movements of a post-nesting River Terrapin, with hopes that it would provide the preliminary baseline information on the utilization of adjacent nesting banks. The solution was a GPS tracking device that transmitted coordinates every hour over cellular networks. Location-based data was sent via Short Message Service (SMS) to our own SMS gateway running on a Raspberry Pi credit-card size computer, which was then logged in a database and presented graphically via Google Maps. It was a complete tracking and monitoring system. This solution enabled researchers to remotely track the movements of a River Terrapin, hence reducing the costs of research. The movements of a post-nesting River Terrapin were tracked for eight days before the battery was drained. On the third day, this River Terrapin ascended an adjacent riverbank and spent less than an hour on the bank, presumably to deposit her remaining eggs. This study confirmed that River Terrapins do utilize other suitable nesting banks if/whenever available. Results from such tracking studies will be used to leverage on the protection of adjacent nesting banks, thus providing greater protection for the critically endangered River Terrapins.

  16. Fluctuación poblacional de Xyleborus ferrugineus y X. affinis (Coleoptera: Curculionidae en ecosistemas de Tabasco, México

    Directory of Open Access Journals (Sweden)

    Ricardo Rangel

    2012-12-01

    Full Text Available Los Scolytinae son insectos comúnmente conocidos como coleópteros descortezadores o ambrosiales debido a su forma de alimentarse. Existen especies que restringen su actividad reproductiva a una planta huésped o a un número reducido de ellas, otras son altamente polífagas. Se estudiaron las poblaciones de Scolytinae con el objetivo de conocer la fluctuación poblacional de X. ferrugineus y X. affinis en ecosistemas de Tabasco, México durante noviembre 2010-julio 2011, febrero 2010-enero 2011 y 2007. Los métodos de captura utilizados fueron trampa de alcohol, trampa de luz y captura directa sobre sus plantas huésped. Se recolectaron 688 especímenes de X. ferrugineus y 3 911 de X. affinis. La fluctuación poblacional de X. ferrugineus mostró de manera general poblaciones bajas en los ecosistemas estudiados sin alguna estacionalidad marcada, registrándose los máximos picos poblacionales tanto en época seca (marzo-mayo como lluviosa (septiembre-diciembre. A diferencia de las poblaciones de X. affinis que fueron más abundantes y mostraron en la mayoría de los sitios (excepto en el Jardín Botánico José Narciso Rovirosa que se presentó en mayo picos poblacionales en época lluviosa. Las trampas de alcohol y de luz son métodos de recolecta que pueden ser complementarios para el monitoreo de las poblaciones de estos insectos, los cuales se encuentran presentes durante la mayor parte del año y su fluctuación poblacional es dependiente de los recursos alimenticios y sobre todo de factores ambientales como la temperatura y humedad. Se sugiere que X. affinis se ha adaptado y explotado los recursos de mejor manera que X. ferrugineus en estos ecosistemas, a juzgar por la abundancia observada. Las correlaciones entre la abundancia y los factores climáticos presentaron valores positivos y negativos. Los resultados reflejan el comportamiento de las poblaciones, sin embargo, hace falta evaluar de manera detallada algunos factores biol

  17. Fluctuación poblacional de Xyleborus ferrugineus y X. affinis (Coleoptera: Curculionidae) en ecosistemas de Tabasco, México

    OpenAIRE

    Rangel,Ricardo; Pérez, Manuel; Sánchez, Saúl; Capello, Silvia

    2012-01-01

    Los Scolytinae son insectos comúnmente conocidos como coleópteros descortezadores o ambrosiales debido a su forma de alimentarse. Existen especies que restringen su actividad reproductiva a una planta huésped o a un número reducido de ellas, otras son altamente polífagas. Se estudiaron las poblaciones de Scolytinae con el objetivo de conocer la fluctuación poblacional de X. ferrugineus y X. affinis en ecosistemas de Tabasco, México durante noviembre 2010-julio 2011, febrero 2010-enero 2011 y ...

  18. Effects of Predation by Invasive Western Mosquitofish (Gambusia affinis) on Survival of Eggs, Embryos and Tadpoles of Pelophylax nigromaculatus and Duttaphrynus melanostictus in South China

    Institute of Scientific and Technical Information of China (English)

    Xiaoli FAN; Zhihua LIN; Xiang LI; Li WEI; Guohua DING

    2016-01-01

    Alien species are one of the most serious threats to the decline and extinction of native amphibian populations. In this study, we examined the predation of invasive Western Mosquitofish Gambusia affinis on the eggs, embryos, and tadpoles of Duttaphrynus melanostictus and Pelophylax nigromaculatus in south China. Our results suggested that the survival of eggs and embryos remaining in the egg capsules of P. nigromaculatus and D. melanostictus was significantly higher than those removed from the egg capsule at 12-h intervals within 72 h in the presence of G. affinis. The survival of P. nigromaculatus eggs and embryos without egg capsules was significantly lower than those of D. melanostictus without egg capsules. The survival of P. nigromaculatus eggs and embryos with egg capsules was significantly higher than those of D. melanostictus with egg capsules from 24 h to 72 h except for 12 h. The survival of D. melanostictus tadpoles was significantly higher than that of P. nigromaculatus tadpoles in the presence of G. affinis. The survival of Gosner stage 26 tadpoles of P. nigromaculatus was significantly higher than that of Gosner stage 30 tadpoles from 12 h to 60 h, but there were no significant differences at 72 h. In contrast, the survival of Gosner stage 26 tadpoles of D. melanostictus was significantly lower than that of Gosner stage 30 tadpoles within 72 h, recording every 12h. The increasing temperature caused a significant increase in predation by G. affinis on P. nigromaculatus eggs and embryos. The outer jelly capsule surrounding anurans eggs might serve as a mechanical defense against predation by G. affinis due to its large diameter, relatively stationary state and unpalatability. The differences in the vulnerability of P. nigromaculatus and D. melanostictus embryos and tadpoles to G. affinis probably due to differences in the unpalatability, black skin and activity. Based on the magnitude of predation by G. affinis on the eggs, embryos and tadpoles of

  19. Temperature effects on copepod egg hatching: does acclimatization matter?

    DEFF Research Database (Denmark)

    Hansen, Benni Winding; Drillet, Guillaume; Kozmér, A.;

    2010-01-01

    This report investigates female sizes, egg sizes and egg hatching rates in relation to temperature for the near-shore calanoid copepod Acartia tonsa cultured at 6, 9, 14 and 24°C for several generations to achieve acclimatization. Inverse size relationships of eggs and females were revealed...... with increasing temperature. Eggs produced at 6°C were 85 ± 4 µm in diameter, but decreased to 80 ± 3 µm at 24°C. Female cephalothorax length was 840 ± 52 and 692 ± 39 µm at 9 and 24°C, respectively. Parallel hatching experiments were performed between non-acclimatized and acclimatized cultures across a range...... of temperatures reflecting natural conditions in Danish waters. A greater fraction of eggs enter quiescence as temperature declines. Eggs were able to hatch at temperatures as low as 1.5°C. Final egg hatching success increased with temperature. Acclimatization of the copepods resulted in a lower maximum hatching...

  20. Circular polarization of transmitted light by sapphirinidae copepods.

    Directory of Open Access Journals (Sweden)

    Yuval Baar

    Full Text Available Circularly polarized light, rare in the animal kingdom, has thus far been documented in only a handful of animals. Using a rotating circular polarization (CP analyzer we detected CP in linearly polarized light transmitted through epipelagic free living Sapphirina metallina copepods. Both left and right handedness of CP was detected, generated from specific organs of the animal's body, especially on the dorsal cephalosome and prosome. Such CP transmittance may be generated by phase retardance either in the muscle fibers or in the multilayer membrane structure found underneath the cuticle. Although the role, if any, played by circularly polarized light in Sapphirinidae has yet to be clarified, in other animals it was suggested to take part in mate choice, species recognition, and other forms of communication.Planktonic Sapphirinidae copepods were found to circularly polarize the light passing through them. Circular polarization may be created by unique, multilayered features of the membrane structure found under their cuticle or by organized muscle fibers.

  1. Impacts of intraguild predation on Arctic copepod communities

    Directory of Open Access Journals (Sweden)

    Karolane Dufour

    2016-09-01

    Full Text Available Communities of large copepods form an essential hub of matter and energy fluxes in Arctic marine food webs. Intraguild predation on eggs and early larval stages occurs among the different species of those communities and it has been hypothesized to impact its structure and function. In order to better understand the interactions between dominant copepod species in the Arctic, we conducted laboratory experiments that quantified intraguild predation between the conspicuous and omnivorous Metridia longa and the dominant Calanus hyperboreus. We recorded individual egg ingestion rates for several conditions of temperature, egg concentration and alternative food presence. In each of these experiments, at least some females ingested eggs but individual ingestion rates were highly variable. The global mean ingestion rate of M. longa on C. hyperboreus eggs was 5.8 eggs ind-1 d-1, or an estimated 37% of M. longa daily metabolic need. Among the different factors tested and the various individual traits considered (prosome length, condition index, only the egg concentration had a significant and positive effect on ingestion rates. We further explored the potential ecological impacts of intraguild predation in a simple 1D numerical model of C. hyperboreus eggs vertical distribution in the Amundsen Gulf. Our modelling results showed an asymmetric relationship in that M. longa has little potential impact on the recruitment of C. hyperboreus (< 3% egg standing stock removed by IGP at most whereas the eggs intercepted by the former can account for a significant portion of its metabolic requirement during winter (up to a third.

  2. Prey detection and prey capture in copepod nauplii.

    Directory of Open Access Journals (Sweden)

    Eleonora Bruno

    Full Text Available Copepod nauplii are either ambush feeders that feed on motile prey or they produce a feeding current that entrains prey cells. It is unclear how ambush and feeding-current feeding nauplii perceive and capture prey. Attack jumps in ambush feeding nauplii should not be feasible at low Reynolds numbers due to the thick viscous boundary layer surrounding the attacking nauplius. We use high-speed video to describe the detection and capture of phytoplankton prey by the nauplii of two ambush feeding species (Acartia tonsa and Oithona davisae and by the nauplii of one feeding-current feeding species (Temora longicornis. We demonstrate that the ambush feeders both detect motile prey remotely. Prey detection elicits an attack jump, but the jump is not directly towards the prey, such as has been described for adult copepods. Rather, the nauplius jumps past the prey and sets up an intermittent feeding current that pulls in the prey from behind towards the mouth. The feeding-current feeding nauplius detects prey arriving in the feeding current but only when the prey is intercepted by the setae on the feeding appendages. This elicits an altered motion pattern of the feeding appendages that draws in the prey.

  3. Paternal inheritance of the primary sex ratio in a copepod.

    Science.gov (United States)

    Voordouw, M J; Robinson, H E; Anholt, B R

    2005-09-01

    Uniparentally inherited genetic elements are under strong selection to manipulate sex determination in their host and shift the host sex ratio towards the transmitting sex. For any sex-ratio trait, lineage analysis and quantitative genetics are important tools for characterizing the mode of inheritance (biparental vs. maternal vs. paternal) thereby narrowing the field of possible sex-determining mechanisms (e.g. polygenic, sex chromosomes with meiotic drive, cytoplasmic microorganisms). The primary sex ratio of the harpacticoid copepod, Tigriopus californicus is often male-biased and is highly variable among full sib families. We found that this extra-binomial variation for the primary sex ratio is paternally but not maternally transmitted in T. californicus. Paternal transmission of the primary sex ratio has been well documented in the haplo-diploid hymenoptera but is relatively rare in diplo-diploid organisms. If the sex-ratio trait is paternally transmitted in other closely related harpacticoid copepods it would explain why male biased primary sex ratios are so common in this group.

  4. The kinematics of swimming and relocation jumps in copepod nauplii

    DEFF Research Database (Denmark)

    Borg, Marc Andersen; Bruno, Eleonora; Kiørboe, Thomas

    2012-01-01

    Copepod nauplii move in a world dominated by viscosity. Their swimming-by-jumping propulsion mode, with alternating power and recovery strokes of three pairs of cephalic appendages, is fundamentally different from the way other microplankters move. Protozoans move using cilia or flagella, and cop......Copepod nauplii move in a world dominated by viscosity. Their swimming-by-jumping propulsion mode, with alternating power and recovery strokes of three pairs of cephalic appendages, is fundamentally different from the way other microplankters move. Protozoans move using cilia or flagella......, and copepodites are equipped with highly specialized swimming legs. In some species the nauplius may also propel itself more slowly through the water by beating and rotating the appendages in a different, more complex pattern. We use high-speed video to describe jumping and swimming in nauplii of three species...... larger copepodites. A slow-swimming mode is only displayed by T. longicornis. In this mode, beating of the appendages results in the creation of a strong feeding current that is about 10 times faster than the average translation speed of the nauplius. The nauplius is thus essentially hovering when...

  5. Bioaccumulation and trophic transfer of dioxins in marine copepods and fish

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Qiong [Division of Life Science, Hong Kong University of Science and Technology (HKUST), Clear Water Bay, Kowloon (Hong Kong); School of Environment, State Key Laboratory of Pollutant Control and Resource Reuse, Nanjing University, Nanjing (China); Yang Liuyan [School of Environment, State Key Laboratory of Pollutant Control and Resource Reuse, Nanjing University, Nanjing (China); Wang Wenxiong, E-mail: wwang@ust.hk [Division of Life Science, Hong Kong University of Science and Technology (HKUST), Clear Water Bay, Kowloon (Hong Kong)

    2011-12-15

    Despite the great concerns about dioxins in the marine environments, the biokinetics and bioaccumulation of these compounds in marine organisms remains little known. Using radioactive tracers the aqueous uptake, dietary assimilation efficiency, and elimination of dioxins were measured in marine phytoplankton, copepods and seabream. The calculated uptake rate constant of dioxins decreased with increasing trophic levels, whereas the dietary assimilation efficiency (AE) was 28.5-57.6% in the copepods and 36.6-70.2% in the fish. The dietary AE was highly dependent on the food concentrations and food type. The elimination rate constant of dioxin in the copepods varied with different exposure pathways as well as food concentration and food type. Biokinetic calculation showed that dietary accumulation was the predominant pathway for dioxin accumulation in marine copepods and fish. Aqueous uptake can be an important pathway only when the bioconcentration of dioxins in the phytoplankton was low. - Highlights: > Radiotracer was used to quantify the biokinetics of dioxins in a marine food chain. > Aqueous uptake rate of dioxins decreased with increasing trophic levels. > Dietary assimilation efficiencies were comparable between the copepods and the fish. > Both food type and density significantly affected the dietary assimilation of dioxins. > Diet was the predominant pathway for dioxin accumulation in marine copepods and fish. - Biokinetic calculation showed that dietary accumulation was the predominant pathway for dioxin accumulation in marine copepods and fish.

  6. Seasonal variability of planktonic copepods (Copepoda: Crustacea in a tropical estuarine region in Brazil

    Directory of Open Access Journals (Sweden)

    Cristina de Oliveira Dias

    2009-12-01

    Full Text Available The Caravelas River estuary and adjacent coastal region were studied during the rainy and dry seasons of 2003-2004 to assess the copepod community structure. Abiotic and biotic parameters were measured, and the total density, frequency and percentage of copepod taxa were determined for each sampling period. Copepod densities showed significant differences between sampling periods, with higher densities in the rainy seasons (Mean: 90,941.80 ind.m-3; S.D.: 26,364.79. The sampling stations located to the north and south, in the coastal region adjacent to the Caravelas River estuary presented the lowest copepod density values. The copepod assemblage was composed mainly of estuarine and estuarine/coastal copepods. The seasonal variations in temperature and salinity influenced the abundance of species during the rainy and dry seasons, with the following dominant species alternating: Paracalanus quasimodo Bowman, 1971 in the rainy season of 2003, Parvocalanus crassirostris Dahl, 1894 in the dry season of 2003 and Acartia lilljeborgii Giesbrecht, 1892 in the rainy and dry seasons of 2004. Non-parametric multidimensional scaling indicated differences in copepod assemblages between sampling periods, but not between sampling stations.

  7. Fluctuación poblacional de Xyleborus ferrugineus y X. affinis (Coleoptera: Curculionidae en ecosistemas de Tabasco, México Population fluctuation of Xyleborus ferrugineus and X. affinis (Coleoptera: Curculionidae in ecosystems of Tabasco, Mexico

    Directory of Open Access Journals (Sweden)

    Ricardo Rangel

    2012-12-01

    Full Text Available Los Scolytinae son insectos comúnmente conocidos como coleópteros descortezadores o ambrosiales debido a su forma de alimentarse. Existen especies que restringen su actividad reproductiva a una planta huésped o a un número reducido de ellas, otras son altamente polífagas. Se estudiaron las poblaciones de Scolytinae con el objetivo de conocer la fluctuación poblacional de X. ferrugineus y X. affinis en ecosistemas de Tabasco, México durante noviembre 2010-julio 2011, febrero 2010-enero 2011 y 2007. Los métodos de captura utilizados fueron trampa de alcohol, trampa de luz y captura directa sobre sus plantas huésped. Se recolectaron 688 especímenes de X. ferrugineus y 3 911 de X. affinis. La fluctuación poblacional de X. ferrugineus mostró de manera general poblaciones bajas en los ecosistemas estudiados sin alguna estacionalidad marcada, registrándose los máximos picos poblacionales tanto en época seca (marzo-mayo como lluviosa (septiembre-diciembre. A diferencia de las poblaciones de X. affinis que fueron más abundantes y mostraron en la mayoría de los sitios (excepto en el Jardín Botánico José Narciso Rovirosa que se presentó en mayo picos poblacionales en época lluviosa. Las trampas de alcohol y de luz son métodos de recolecta que pueden ser complementarios para el monitoreo de las poblaciones de estos insectos, los cuales se encuentran presentes durante la mayor parte del año y su fluctuación poblacional es dependiente de los recursos alimenticios y sobre todo de factores ambientales como la temperatura y humedad. Se sugiere que X. affinis se ha adaptado y explotado los recursos de mejor manera que X. ferrugineus en estos ecosistemas, a juzgar por la abundancia observada. Las correlaciones entre la abundancia y los factores climáticos presentaron valores positivos y negativos. Los resultados reflejan el comportamiento de las poblaciones, sin embargo, hace falta evaluar de manera detallada algunos factores biol

  8. [Response of copepod community characteristics to environmental factors in the Backshore Wetland of Expo Garden, Shanghai].

    Science.gov (United States)

    Chen, Li-Jing; Wu, Yan-Fang; Jing, Yu-Xiang; Wang, Cong; Zhang, Yin-Jiang

    2012-11-01

    The Backshore Wetland of Expo Garden was the emphasis of the World Expo construction project in Shanghai in 2010, China programming district. We carried out studies on the community structure and spatial-temporal variation of copepod from September 2009 to August 2010. Statistical Product and Service Solutions (SPSS) was used for relevant statistical analysis between physicochemical parameters and copepod standing crop. Canonical correspondence analysis (CCA) was applied to further explore the correlation between copepod species and environmental parameters using CANOCO 4.5. A total of 23 copepod species in 11 genera, 6 families were identified. 5 dominant species of copepod were recorded during the survey period. They were Eucyclops serrulatus, Thermocyclops taihokuensis, Mesocyclops leuckarti, Thermocyclops brevifurcatus and Microcyclops varicans. The annual mean density of copepod was (8.6 +/- 16.6) ind x L(-1) and the biomass was (0.083 6 +/- 0.143 1) mg x L(-1). The standing crop of copepod had its first peak in July, the second in October and the bottom in January. The highest trophic level was measured at Site 1, decreasing along the flowing direction of the water current, and the lowest level was found at Site 10. The Margelf index remained low in winter and spring, but was increased in summer and autumn. The community structure of copepod was analyzed in relation to water quality parameters by canonical correspondence analysis (CCA). Water temperature, pH, nitrate nitrogen, nitrite nitrogen, TN, TP and dissolved oxygen were strongly correlated with the copepod community structure.

  9. Vertical distribution, grazing and egg production of calanoid copepods during winter-spring in Gullmarsfjorden

    DEFF Research Database (Denmark)

    Titelman, J.; Tiselius, P.

    1998-01-01

    The vertical distribution of copepods in relation to their potential food was examined in Gullmarsfjorden, Sweden (58 degrees 15.6' N, 11 degrees 27.2' E). Plankton distributions were determined from bottle samples at 5 m intervals on four occasions; 30 January, 28 February, 7 March and 10 April...... were superfluous throughout the water column. Copepods and ciliates were never correlated. Ingestion as determined from gut fluorescence and egg production analyses suggested a higher degree of herbivory during the spring bloom than before and after. There was potential for copepod predation control...

  10. Female-biased sex ratios in marine pelagic copepods: Comment on Gusmao et al. (2013)

    DEFF Research Database (Denmark)

    Hirst, Andrew G.; Bonnet, D; Conway, DVP

    2013-01-01

    Gusmao et al. (2013; Mar Ecol Prog Ser 482:279-298) review causes of sex ratio skew in pelagic copepods and in doing so repeatedly dispute the paper of Hirst et al. (2010) ‘Does predation control adult sex ratios and longevities in marine pelagic copepods?’ Here we respond to some important errors...... in their citation of our paper and briefly highlight where future work is needed in order to attribute the causes of strong sex ratio skew seen in some copepod families...

  11. Chromosomal study of two fish species: Cobitis (C. taenia, Nemachilus tigris and Gambusia Affinis in the Orontes river

    Directory of Open Access Journals (Sweden)

    M. Roukbi

    2014-06-01

    Full Text Available Research was done during the period (October 2009 to September 2010, aiming to identify two species of Cobitis (Cobitis taenia and Nemachilus tigris belonging to Cobitidae and Gambusia affnis by using karyotype examination. Fish specimens were caught alive from the river Orontes drainage and its tributaries in Idlib and Hama departments by routine fishing gears, and submitted Colchcine treatment in Aleppo agricultural research center, General commission for Scientific Agricultural research which included an incubating in Colchicine medium (0.06% for 2.5 -3 hours. Fishes were chopped and placed in hypotonic 0.4% KCl solution for 30 min. Afterwards, tissues were fixed in fresh Carnoy solution (3 parts methanol: 1 part glacial acetic acid. Cell suspension was dropped onto slides, dried and then stained in 4% Giemsa solution. Chromosome spreads on microscope slides were examined and several metaphase plates were selected and photographed. Chromosomes of fish studied were grouping into series, i. e., meta-submetacentric and subtelocentric-acrocentric elements, and aligned serially from the larger to smaller, karyograms were constructed and chromosomal formulas and the number of arms were established, as following: Cobitis taenia: 2n=50=14m/sm+36t/st (NF=64, Nemachilus tigris: 2n=50=12m/sm+38t/st (NF=62, Gambusia affinis (female: 2n=48=1m+2sm+45t/st(NF=51, Gambusia affinis(males: 2n=48=2m+46t (NF=50(. A

  12. Effect of an acute and chronic toxicity of four commercial detergents on the freshwater fish Gambusia affinis Baird & Gerard.

    Science.gov (United States)

    Saxena, Pratibha; Sharma, Subhasini; Sharma, Shweta; Suryavathi, V; Grover, Ruby; Soni, Pratima; Kumar, Suresh; Sharma, K P

    2005-04-01

    The toxic effects of four commercial detergents (two washing powders and two cakes) are reported in this paper on behavior, mortality and RBC counts of a freshwater fish Gambusia affinis. During acute toxicity studies (96h), surface movements of fish increased markedly for 24h, only at higher concentrations (>10 ppm) of all the four detergents. Thereafter, they were lethargic and bottom dwellers similar to those exposed for a period of 30 days in the longterm ecotoxicological studies made on detergent powders at a sublethal concentration (10 ppm). The detergents exposed to fish were found slippery due to mucous secretion. Hemorrhage regions were also found on their gills. The dissolved oxygen content also decreased (10-18%) in the detergent treatments of higher concentration (> 10 ppm). During acute toxicity studies, cakes (LC50 = 6.69 - 19.98ppm) were found more toxic than powders (LC50 = 18.34-20.72ppm). In comparison to the control fish, RBC counts decreased (12-64%) in the detergent exposed fish, being more pronounced among those exposed to cakes. The chronic exposure (30 days) of the fish also resulted in reduction in the RBC counts (41-58%). It is thus evident that all the four detergents are toxic to the fish Gambusia affinis.

  13. Solid phase extraction and metabolic profiling of exudates from living copepods

    DEFF Research Database (Denmark)

    Selander, Erik; Heuschele, Jan; Nylund, Göran M.

    2016-01-01

    Copepods are ubiquitous in aquatic habitats. They exude bioactive compounds that mediate mate finding or induce defensive traits in prey organisms. However, little is known about the chemical nature of the copepod exometabolome that contributes to the chemical landscape in pelagic habitats. Here we...... describe the development of a closed loop solid phase extraction setup that allows for extraction of exuded metabolites from live copepods. We captured exudates from male and female Temora longicornis and analyzed the content with high resolution LC-MS. Chemometric methods revealed 87 compounds...... that constitute a specific chemical pattern either qualitatively or quantitatively indicating copepod presence. The majority of the compounds were present in both female and male exudates, but nine compounds were mainly or exclusively present in female exudates and hence potential pheromone candidates...

  14. Composition and physical state of phospholipids in calanoid copepods from India and Norway

    Digital Repository Service at National Institute of Oceanography (India)

    Farkas, T.; Storebakken, T.; Bhosle, N.B.

    the adaptation of membrane lipids with seawater temperatures Phospholipid vesicles obtained from the tropic copepods proved more rigid than those from C finmarchicus, as assessed by diphenylhexatriene fluorescence polarization techniques In each case, there were...

  15. Toxicity of selected pesticides to the groundwater copepod Parastenocaris germanica (Crustacea)

    NARCIS (Netherlands)

    Notenboom J; Boessenkool JJ; ECO

    1994-01-01

    De toxiciteit van negen verschillende bestrijdingsmiddelen of afbraakproducten voor de grondwater copepod Parstenocaris germanica is onderzocht. De onderzochte stoffen zijn geselecteerd vanwege hun potentieel gevaar voor grondwater bewonende metazoen. Niet alle experimenten lieten een duidelijke

  16. Coexistence and succession of copepod species in the Mandovi and Zuari estuaries, Goa

    Digital Repository Service at National Institute of Oceanography (India)

    Goswami, S.C.

    correlated or associated either over space or time. The pattern of copepod succession based on species dominance revealed three main types with successional sequence of high saline species (greater than 30 ppt), low saline species (greater than 5 ppt...

  17. Studies of community structure and seasonal dynamics of planktonic copepods in saline-alkaline ponds

    Institute of Scientific and Technical Information of China (English)

    ZHAO Wen; DONG Shuanglin

    2005-01-01

    Species abundance and seasonal succession of copepods in aline-alkaline ponds were studied in Zhaodian Fish Farm, Gaoqing County, Shandong Province, from 5 April 1997 to 1 September 1998. The results indicated that in the conditions of salinity ranging from 1.36 to 20 g/L, total alkalinity changing from 2.4 to 7.2 mmol/L and pH 8-9, zooplankton in saline-alkaline ponds was composed of freshwater salt-tolerated species or halophile species, some of which are halobiont species and usually occurs in freshwater In our study, copepods were predominant in many fish-culture ponds and all control ponds without fishes in spring, late autumn and early winter Dominant species of copepods were Sinocalanus tenellus, Cyclops vicinus, Thermocyclops taihokuensis. The biomass of copepods in the control ponds without fishes was higher than that of the fish-culture ponds. ponds.

  18. Eradication of Aedes aegypti from a village in Vietnam, using copepods and community participation

    National Research Council Canada - National Science Library

    Vu, SN; Nguyen, TY; Kay, BH; Marten, GG; Reid, JW

    1998-01-01

    In northern Vietnam, copepods of the genus Mesocyclops were used for biological control of Aedes aegypti, the principal vector of dengue viruses, by inoculation into wells, large cement tanks, ceramic...

  19. Sex Conversion Induced by Hydrostatic Pressure in the Marine Copepod Tigriopus californicus.

    Science.gov (United States)

    Vacquier, V D; Belser, W L

    1965-12-17

    High hydrostatic pressure applied to the naupliar larval stages of the marine copepod Tigriopus californicus converts some individuals that would have become males into females. The copepodid stages are not sensitive to pressureinduced conversion.

  20. SWIMMING BEHAVIOR OF DEVELOPMENTAL STAGES OF THE CALANOID COPEPOD TEMORA-LONGICORNIS AT DIFFERENT FOOD CONCENTRATIONS

    NARCIS (Netherlands)

    VANDUREN, LA; VIDELER, JJ

    1995-01-01

    The swimming behaviour of developmental stages of the marine calanoid copepod Temora longicornis was studied using 2-dimensional observations under a microscope and a 3-dimensional filming technique to analyze swimming mode, swimming speed and swimming trajectories under different food

  1. Recent advances within intensive Recirculated Aquaculture System cultivation of the calanoid copepod Acartia tonsa (Dana)

    DEFF Research Database (Denmark)

    Jepsen, Per Meyer; Højgaard, Jacob Kring; Drillet, Guillaume;

    2014-01-01

    Danish aquaculture has within recent years focused upon rearing of new marine fish species. A major challenge for rearing of marine fish species is relevant diets for their fish larvae. Copepods and their larvae stage “nauplii” are well documented as the ideal live feed for a variety of marine...... and the nauplii can be feed to marine fish larvae. A restriction is that copepod cultures for producing eggs are after 30 years of research still not stable and in large enough scale for bulk production of eggs. Recently a unique copepod Recirculated Aquaculture System (RAS) at Roskilde University (Denmark......) was constructed as a part of the IMPAQ project “IMProvement of AQuaculture high quality fish fry production”. We present recent advance within RAS culture for copepods, and lesson learned from rearing the specie. Further we present physical and biological culture restrictions in terms of water quality (NH3...

  2. Free-living copepods of the Arabian Sea: Distributions and research perspectives

    Digital Repository Service at National Institute of Oceanography (India)

    Madhupratap, M.

    11500 known species in this subclass. This paper briefly outlines the distribution, abundances and general feeding habitats of free-living copepods from the Arabian Sea. The role of taxonomy in biodiversity studies, estimates of grazing and production...

  3. On the occurrence of endoparasites from copepods of the west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Santhakumari, V.

    Occurrence of endoparasitic dinoflagellates belonging to the genera, Blastodinium, parasitizing the coelomic cavity of their host, copepods was investigated. Infection by these species seems to be harmful to the host. Parasitized individuals showed...

  4. First evidence of tumor-like anomaly infestation in Copepods from the central Indian Ridge

    Digital Repository Service at National Institute of Oceanography (India)

    Bhandare, C.; Ingole, B.S.

    attack, especially to ectoparasites like Ellobiopsis sp. These ectoparasites attack the host and feed on their body fluids which may lead to the death of the host. This study emphasis the consequences of parasitic infection in dominant planktonic copepods...

  5. Motility of copepod nauplii and implications for food encounter

    DEFF Research Database (Denmark)

    Titelman, Josefin; Kiørboe, Thomas

    2003-01-01

    Velocity differences drive all encounter processes. Therefore, knowledge of both prey and predator motility are essential in order to understand feeding behavior and predict food acquisition rates. Here, we describe and quantify the motility behavior of young and old naupliar stages of 6 copepods...... of tracks, speeds, durations and frequencies of events as well as time budgets. Motility mode often changes drastically during naupliar ontogeny. Crudely, nauplii can be divided into those moving with a jump-sink type of motility of various frequencies (1 min(-1) to 3 s(-1)) and those swimming...... with a smoother glide of varying continuity. We apply observed time budgets and behavior-specific speeds in simple models to examine mechanisms of food encounter. The motility of all nauplii may account for clearance rates reported in the literature, but through different mechanisms. Smoothly swimming nauphi...

  6. Magnetic light cloaking control in the marine planktonic copepod Sapphirina

    Science.gov (United States)

    Kashiwagi, H.; Mizukawa, Y.; Iwasaka, M.; Ohtsuka, S.

    2017-05-01

    We investigated the light cloaking behavior of the marine planktonic copepod Sapphirina under a magnetic field. Optical interferences in the multi-laminated guanine crystal layer beneath the dorsal body surface create a brilliant structural color, which can be almost entirely removed by changing the light reflection. In the investigation, we immersed segments of Sapphirina in seawater contained in an optical chamber. When the derived Sapphirina segments were attached to the container surface, they were inert to magnetic fields up to 300 mT. However, when the back plate segments were attached to the substrate at a point, with most of the plate floating in the seawater, the plate rotated oppositely to the applied magnetic field. In addition, the brilliant parts of the Sapphirina back plate rotated backward and forward by changing the magnetic field directions. Our experiment suggests a new model of an optical micro-electro-mechanical system that is controllable by magnetic fields.

  7. Heritability of sex tendency in a harpacticoid copepod, Tigriopus californicus.

    Science.gov (United States)

    Voordouw, Maarten J; Anholt, Bradley R

    2002-09-01

    Systems with genetic variation for the primary sex ratio are important for testing sex-ratio theory and for understanding how this variation is maintained. Evidence is presented for heritable variation of the primary sex ratio in the harpacticoid copepod Tigriopus californicus. Variation in the primary sex ratio among families cannot be accounted for by Mendelian segregation of sex chromosomes. The covariance in sex phenotype between full-sibling clutches and between mothers and offspring suggests that this variation has a polygenic basis. Averaged over four replicates, the full-sibling heritability of sex tendency is 0.13 +/- 0.040; and the mother-offspring heritability of sex tendency is 0.31 +/- 0.216. Genetic correlations in the sex phenotype across two temperature treatments indicate large genotype-by-temperature interactions. Future experiments need to distinguish between zygotic, parental, or cytoplasmic mechanisms of sex determination in T. californicus.

  8. Optimal swimming strategies in mate searching pelagic copepods

    DEFF Research Database (Denmark)

    Kiørboe, Thomas

    2008-01-01

    Male copepods must swim to find females, but swimming increases the risk of meeting predators and is expensive in terms of energy expenditure. Here I address the trade-offs between gains and risks and the question of how much and how fast to swim using simple models that optimise the number...... of lifetime mate encounters. Radically different swimming strategies are predicted for different feeding behaviours, and these predictions are tested experimentally using representative species. In general, male swimming speeds and the difference in swimming speeds between the genders are predicted...... and observed to increase with increasing conflict between mate searching and feeding. It is high in ambush feeders, where searching (swimming) and feeding are mutually exclusive and low in species, where the matured males do not feed at all. Ambush feeding males alternate between stationary ambush feeding...

  9. The kinematics of swimming and relocation jumps in copepod nauplii.

    Directory of Open Access Journals (Sweden)

    Christian Marc Andersen Borg

    Full Text Available Copepod nauplii move in a world dominated by viscosity. Their swimming-by-jumping propulsion mode, with alternating power and recovery strokes of three pairs of cephalic appendages, is fundamentally different from the way other microplankters move. Protozoans move using cilia or flagella, and copepodites are equipped with highly specialized swimming legs. In some species the nauplius may also propel itself more slowly through the water by beating and rotating the appendages in a different, more complex pattern. We use high-speed video to describe jumping and swimming in nauplii of three species of pelagic copepods: Temora longicornis, Oithona davisae and Acartia tonsa. The kinematics of jumping is similar between the three species. Jumps result in a very erratic translation with no phase of passive coasting and the nauplii move backwards during recovery strokes. This is due to poorly synchronized recovery strokes and a low beat frequency relative to the coasting time scale. For the same reason, the propulsion efficiency of the nauplii is low. Given the universality of the nauplius body plan, it is surprising that they seem to be inefficient when jumping, which is different from the very efficient larger copepodites. A slow-swimming mode is only displayed by T. longicornis. In this mode, beating of the appendages results in the creation of a strong feeding current that is about 10 times faster than the average translation speed of the nauplius. The nauplius is thus essentially hovering when feeding, which results in a higher feeding efficiency than that of a nauplius cruising through the water.

  10. Propulsion and perception in intermediate Re regimes: aquatic microcrustacean copepod responses to wake structures.

    Science.gov (United States)

    Yen, J.; Pender Healy, L. A.; Heaphy, M.

    2016-02-01

    Flow sensing by the mechanoreceptive cuticular arrays of sensors on copepods has been shaped by over 400 million years of evolution and plays an important role in predator avoidance, foraging, mating, and rheotaxis. These 3D wakes are produced by animal propulsive activities and contain cues that guide these key survival responses. We have demonstrated that the fluid mechanical and chemical information retained in the hydrodynamic envelope can be interpreted by suitable sensor arrays; copepod sensor arrays are capable of perceiving minute differences in wake structures. Temora longicornis, a coastal marine copepod, and Hesperodiaptomus shoshone, a high-alpine freshwater lake copepod, track laminar trails. High-speed videography coupled with high-magnification Schlieren optics enabled us to visualize the deformation of the trail signal and the propulsive movements of the male copepod. Males followed the trail mimic and our observations show clear differences between the marine and freshwater species. Comparative analyses reveal tracking mechanisms that differ in sensor location with respect to the trail and locomotory kinematics. Copepods perform directed motions that lead them to a stimulus source in the absence of other collimating stimuli. Tracking by the copepod around the trail allows it to have one or numerous sensors inside and outside the trail to facilitate edge detection using spatial sampling. The advantage of this remarkable behavior of following trails fast and accurately is to encounter mates or food patches more frequently, thus contributing to population recruitment and energy transfer up the trophic food web. Precise mate and food finding strategies found for pelagic copepods may be a key adaptation, promoting survival in these open-ocean planktonic populations.

  11. Effects of Harpacticus sp. (Harpacticoida, copepod) grazing on dimethylsulfoniopropionate and dimethylsulfide concentrations in seawater

    Science.gov (United States)

    Yu, Juan; Tian, Ji-Yuan; Yang, Gui-Peng

    2015-05-01

    We conducted 9 d and 24 h ingestion experiments to investigate the effects of copepod grazing on the concentrations of dimethylsulfoniopropionate (DMSP) and dimethylsulfide (DMS) in seawater. Data from the 9 d trial showed that copepod Harpacticus sp. (Harpacticoida, copepod) grazing increased DMS (0-20%) and dissolved DMSP (DMSPd) (0-128%) apparently, accompanied by a significant reduction of particulate DMSP (DMSPp) in algal culture (0-30%). Ingestion rates (IRs) and pellet production rates (PPRs) of Harpacticus sp. varied with diet species (Platymonas subcordiformis (PS), Nitzschia closterium (NC), Skeletonema costatum (SC), Isochrysis galbana (IG), Prymnesium parvum (PP) or Heterosigma akashiwo (HA)), algal concentration, salinity and temperature. Harpacticus sp. fed on PP showed the lowest IRs (female/male, 0.72/0.53 × 104cells copepod- 1 h- 1) and PPRs (female/male, 0.75/0.5 pellets copepod- 1 h- 1), accompanied with the largest amounts of DMS and DMSPd,p (sum of DMSPd and DMSPp). IRs, PPRs, DMS and DMSPf (DMSP in fecal pellet) increased with the increase of food concentration and peaked at 25 × 104 cells mL- 1I. galbana. High salinity decreased IRs, PPRs, DMS and DMSPf and increased DMSPz (DMSP in copepod body) and DMSPd,p. IRs, PPRs, DMS and DMSPf increased with the increase of temperature from 15 to 25 °C, whereas DMSPz and DMSPd,p contents decreased. Pearson correlation analysis results showed that DMS concentrations presented positive relationships with IRs in algal concentration, salinity and temperature experiments (r = 0.746; P < 0.01). The contribution of DMSPz, DMSPf, DMS and DMSPd,p concentration to the total amounts (DMSPz + DMSPf + DMS + DMSPd,p) was 4-37%, 3-36%, 8-42% and 9-89%, respectively, indicating that DMSP was transferred to copepod tissue and fecal pellet via grazing. Our results are helpful for further understanding of the role of copepod grazing on DMS biogeochemical cycle.

  12. Length frequency distribution, mortality rate and reproductive biology of kawakawa (Euthynnus affinis-Cantor, 1849) in the coastal waters of Tanzania.

    Science.gov (United States)

    Johnson, M G; Tamatamah, A R

    2013-11-01

    This study explored important aspect of the basis for the highly complex population of kawakawa (Euthynnus affinis) within the coastal waters of Tanzania; by investigating length frequency distribution, mortality rate and reproductive characteristics. This information is essential for the sustainable management of the regionally-important recreational and economic E. affinis fishery. Fish were sampled on a monthly basis for two monsoon seasons using a ring net and artisanal fishermen boat. Maximum and minimum total length was 85 and 31 cm, respectively. Nonlinear least square fitting provided a complete set of von Bertalanffy growth estimates: L8 = 89.25 cm total length and K = 0.78. The estimated value of total mortality based on length converted catch curve using these growth parameters is Z = 1.78 year(-1). Natural mortality based on growth parameters and mean environmental temperature (T = 26.9 degrees C) is M = 1.09 year(-1). The estimated annual instantaneous fishing mortality (F = 0.69 year(-1)) was considerably grater than the target (Fopt = 0.43 year(-1)) and limit (Flimit = 0.58 year(-1)) biological reference point indicating that E. affinis is heavily overexploited. Reproductive aspects were assessed whereby female E. affinis was reported to reach maturity earlier than males which is an indication of phenotypic response toward a decline in population. Two peaks was revealed by the use of Gonad-Somatic Index (GSI), however an extended spawning period was noticed in a period between November to February following an increased water temperature. Although, these findings presents a snapshot concerning population structure and reproduction of E. affinis, further studies covering the entire coastal waters of Tanzania are recommended to aid the management and conservation strategies.

  13. Antibiotic-induced change of bacterial communities associated with the copepod Nitocra spinipes.

    Directory of Open Access Journals (Sweden)

    Anna Edlund

    Full Text Available Environmental pressures, such as physical factors, diet and contaminants may affect interactions between microbial symbionts and their multicellular hosts. Despite obvious relevance, effects of antimicrobial contaminants on host-symbiont relations in non-target aquatic organisms are largely unknown. We show that exposure to antibiotics had negative effects on survival and juvenile development of the copepod Nitocra spinipes and caused significant alterations in copepod-associated bacterial communities. The significant positive correlations between indices of copepod development and bacterial diversity indicate that disruption of the microflora was likely to be an important factor behind retarded juvenile development in the experimental animals. Moreover, as evidenced by ribotype distribution in the bacterial clone libraries, the exposure to antibiotics caused a shift in dominance from Betaproteobacteria to Cardinium bacteria; the latter have been shown to cause reproductive manipulations in various terrestrial arthropods. Thus, in addition to providing evidence that the antibiotic-induced perturbation of the microbial community associates with reductions in fitness-related traits of the host, this study is the first record of a copepod serving as a host for endosymbiotic Cardinium. Taken together, our results suggest that (1 antimicrobial substances and possibly other stressors can affect micobiome and symbiont-mediated interactions in copepods and other hosts, and (2 Cardinium endosymbionts may occur in other copepods and affect reproduction of their hosts.

  14. Effects of UV radiation on the RNA/DNA ratio of Copepods from Antarctica and Chile

    Institute of Scientific and Technical Information of China (English)

    Paulo F. Lagos; M. Jesús Valdés; Karen Manríquez

    2015-01-01

    The effect of ultraviolet (UV) radiation on marine organisms has been an important focus of recent research, with depletion of the ozone layer resulting in increased UV radiation at high latitudes. Several studies have identiifed negative impacts of UV radiation on the biology of zooplanktonic organisms. This study used the RNA/DNA ratio as a measure of stress in copepod assemblages from Fíldes Bay in Antarctica and Quintay Bay on the central coast of Chile, two areas with high UV radiation but different photobiologic histories. Controlled time-light experiments were performed with copepods from the two locations, exposing them to white light, UV light, or darkness. The results showed different responses to UV radiation. Copepods from Fíldes Bay showed a slow metabolic response to UV radiation after 4 and 8 h of exposure. Copepods from Quintay Bay showed a fast metabolic response after 4 h of exposure (4 orders of magnitude higher than that for Fíldes Bay copepods) followed by a rapid return toward baseline after 8 h of exposure. These different responses probably relfect the time the copepod assemblages have been exposed to increased UV radiation and the extent of adaptive stress responses to cope with that increased UV radiation. The results of this study show that the RNA/DNA ratio is a useful indicator of the physiologic status of marine organisms and is a useful tool to measure the effects of changing environmental conditions on marine ecosystems, such as those associated with global climate change.

  15. Alternative Methods for Marine Harpacticoid Copepod, Macrosetella gracilis Production in Marine Fish Larviculture

    Directory of Open Access Journals (Sweden)

    N. Jeyaraj

    2014-01-01

    Full Text Available Sustainable aquaculture depends upon eco-friendly, economically and socially viable culture systems. The recycling of organic wastes for plankton culture serves the dual purpose of cleaning the environment and providing economic benefits. There has been no experimentation to measure the effect of organic manure for the aquaculture of copepods, it may be reduced time and labor cost. Hence, the present experiment was conducted to evaluate the mass culture feasibility of Harpacticoid copepod, Macrosetella gracilis using a different organic manures viz., cow dung, poultry manure, goat manure and mixture of these three (1:1:1 ratio at 500 g for each tank manures were decomposed for twelve days before the inoculation of copepod. Twenty adult copepod M. gracilis were inoculated. The peak density was found on 10-14th day of at all doses, among these four doses, significantly higher numbers of organisms 4213.33±213.48 ind. L-1 were found in the cow dung followed by the poultry manure, goat manure and mixed doses 2350.66±148.20; 1573.60±121.41; 995±102, respectively. The number of organisms was ground very low in mixed doses than other doses. Water quality analyses of culture system was no significantly different among the treatments especially pH and salinity. Cow dung manure is therefore recommended for quick and high production of copepod, M. gracilis which invariably reduces the high cost of expensive algae feed for copepod.

  16. High-quality RNA extraction from copepods for Next Generation Sequencing: A comparative study.

    Science.gov (United States)

    Asai, Sneha; Ianora, Adrianna; Lauritano, Chiara; Lindeque, Penelope K; Carotenuto, Ylenia

    2015-12-01

    Despite the ecological importance of copepods, few Next Generation Sequencing studies (NGS) have been performed on small crustaceans, and a standard method for RNA extraction is lacking. In this study, we compared three commonly-used methods: TRIzol®, Aurum Total RNA Mini Kit and Qiagen RNeasy Micro Kit, in combination with preservation reagents TRIzol® or RNAlater®, to obtain high-quality and quantity of RNA from copepods for NGS. Total RNA was extracted from the copepods Calanus helgolandicus, Centropages typicus and Temora stylifera and its quantity and quality were evaluated using NanoDrop, agarose gel electrophoresis and Agilent Bioanalyzer. Our results demonstrate that preservation of copepods in RNAlater® and extraction with Qiagen RNeasy Micro Kit were the optimal isolation method for high-quality and quantity of RNA for NGS studies of C. helgolandicus. Intriguingly, C. helgolandicus 28S rRNA is formed by two subunits that separate after heat-denaturation and migrate along with 18S rRNA. This unique property of protostome RNA has never been reported in copepods. Overall, our comparative study on RNA extraction protocols will help increase gene expression studies on copepods using high-throughput applications, such as RNA-Seq and microarrays. Copyright © 2014 Elsevier B.V. All rights reserved.

  17. A Lagrangian model of Copepod dynamics: clustering by escape jumps in turbulence

    CERN Document Server

    Ardeshiri, Hamidreza; Schmitt, François G; Souissi, Sami; Toschi, Federico; Calzavarini, Enrico

    2016-01-01

    Planktonic copepods are small crustaceans that have the ability to swim by quick powerful jumps. Such an aptness is used to escape from high shear regions, which may be caused either by flow per- turbations, produced by a large predator (i.e. fish larvae), or by the inherent highly turbulent dynamics of the ocean. Through a combined experimental and numerical study, we investigate the impact of jumping behaviour on the small-scale patchiness of copepods in a turbulent environment. Recorded velocity tracks of copepods displaying escape response jumps in still water are here used to define and tune a Lagrangian Copepod (LC) model. The model is further employed to simulate the behaviour of thousands of copepods in a fully developed hydrodynamic turbulent flow obtained by direct numerical simulation of the Navier-Stokes equations. First, we show that the LC velocity statistics is in qualitative agreement with available experimental observations of copepods in tur- bulence. Second, we quantify the clustering of LC...

  18. Observation on Marine Copepod - Appendicularian Naturally Changing Concentrations Along Southwest Coast of India

    Directory of Open Access Journals (Sweden)

    Jean J. JOSE

    2012-11-01

    Full Text Available Patterns of copepod - appendicularian distribution were studied along the Mangalore coastal waters (12�50�49� N; 74�48�50� E of the Arabian Sea to understand the food and feeding relationship existing among these groups. Sampling was conducted during pre-monsoon, monsoon and post-monsoon extending from January 2009 to December 2010. The copepod and appendicularian community was sampled with a 60 ?m net to include the smallest species and their developmental stages. Copepod biomass, especially calanoids, was substantially high throughout the study. Seasonal mean results showed that the small-sized copepods (calanoids, harpacticoida and cyclopoids dominated in terms of biomass and production. Calanoids found in abundance included Acartia, Centropages, Calanus, Eucalanus and Labidocera. Cyclopoid and Harpacticoid copepods genera dominated included Oithona, Oncaea and Microsetella, Macrosetella. Appendicularian species diversity was represented by Oikopleura fusiformis, O. dioica and its juveniles represented as Oikopleura sp. Total chlorophyll (chlorophyll a ranging between 10 and 20 mg m-3 indicated the eutrophic state as well as productivity prevailing during the study period. Principal component analysis (PCA indicated the routine and opportunistic seasonal grazers and establishes a phytoplankton - appendicularia - copepod - fish food chain relationship along Mangalore coast.

  19. Observation on Marine Copepod - Appendicularian Naturally Changing Concentrations Along Southwest Coast of India

    Directory of Open Access Journals (Sweden)

    Jean J. JOSE

    2012-11-01

    Full Text Available Patterns of copepod - appendicularian distribution were studied along the Mangalore coastal waters (125049 N; 744850 E of the Arabian Sea to understand the food and feeding relationship existing among these groups. Sampling was conducted during pre-monsoon, monsoon and post-monsoon extending from January 2009 to December 2010. The copepod and appendicularian community was sampled with a 60 ?m net to include the smallest species and their developmental stages. Copepod biomass, especially calanoids, was substantially high throughout the study. Seasonal mean results showed that the small-sized copepods (calanoids, harpacticoida and cyclopoids dominated in terms of biomass and production. Calanoids found in abundance included Acartia, Centropages, Calanus, Eucalanus and Labidocera. Cyclopoid and Harpacticoid copepods genera dominated included Oithona, Oncaea and Microsetella, Macrosetella. Appendicularian species diversity was represented by Oikopleura fusiformis, O. dioica and its juveniles represented as Oikopleura sp. Total chlorophyll (chlorophyll a ranging between 10 and 20 mg m-3 indicated the eutrophic state as well as productivity prevailing during the study period. Principal component analysis (PCA indicated the routine and opportunistic seasonal grazers and establishes a phytoplankton - appendicularia - copepod - fish food chain relationship along Mangalore coast.

  20. Mesozooplankton affinities in a recovering freshwater estuary

    Science.gov (United States)

    Chambord, Sophie; Maris, Tom; Colas, Fanny; Van Engeland, Tom; Sossou, Akoko-C.; Azémar, Frédéric; Le Coz, Maïwen; Cox, Tom; Buisson, Laetitia; Souissi, Sami; Meire, Patrick; Tackx, Michèle

    2016-08-01

    Water quality of the Scheldt estuary (Belgium/The Netherlands) has considerably improved in recent years, especially in the upstream, freshwater reaches. Within the zooplankton community, the copepod Eurytemora affinis, typically abundant in brackish water and quasi-absent from freshwater before 2007, has since substantially developed in the latter, where it now represents 90% of the crustacean mesozooplankton community. Simultaneously, cyclopoid copepod abundance has greatly decreased, while cladoceran abundance did not change. The study aim was: 1) to verify if the zooplankton community described for the period 2007-2009 by Mialet et al. (2011) has stabilized until present, and 2) to look for the environmental conditions favouring E. affinis development and causing changes in the upstream freshwater zooplankton community. The 2002-2012 temporal evolution of the zooplankton distribution at three stations in the upstream freshwater Scheldt estuary was analyzed. Water quality remained better after 2007 than before, and some factors revealed continuous improvement in annual mean concentrations (e.g. increase in O2, decrease in BOD5 and NH4sbnd N concentration). The increase in oxygen and the decrease in NH4sbnd N concentration, together with low discharge during summer were the main environmental factors explaining the development and timing of E. affinis in the upstream freshwater reach. In this reach, E. affinis maximal abundance is shifted to higher temperatures (summer) compared to its typical maximum spring abundance peak in the brackish zone of the Scheldt estuary and in most temperate estuaries. The changes in zooplankton community followed a temporal and spatial gradient induced by the spatio-temporal evolution of water quality improvement. The most downstream station (3) allowed E. affinis development (oxygen concentration > 4 mg L-1; NH4sbnd N concentration high predation pressure, NH3sbnd N toxicity, sensitivity to oxygen, etc.), there is no clear cause

  1. Iboga alkaloids from Peschiera affinis (Apocynaceae) - unequivocal {sup 1}H and {sup 13}C chemical shift assignments: antioxidant activity; Alcaloides iboga de Peschiera affinis (Apocynaceae) - atribuicao inequivoca dos deslocamentos quimicos dos atomos de hidrogenio e carbono: atividade antioxidante

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Allana Kellen L.; Magalhaes, Ticiane S.; Monte, Francisco Jose Q.; Mattos, Marcos Carlos de; Oliveira, Maria Conceicao F. de; Almeida, Maria Mozarina B.; Lemos, Telma L.G.; Braz-Filho, Raimundo [Universidade Federal do Ceara (UFC), Fortaleza, CE (Brazil). Dept. de Quimica Organica e Inorganica], e-mail: tlemos@dqoi.ufc.br

    2009-07-01

    Six known alkaloids iboga type and the triterpene {alpha}- and {beta}-amyrin acetate were isolated from the roots and stems of Peschiera affinis. Their structures were characterized on the basis of spectral data mainly NMR and mass spectra. 1D and 2D NMR spectra were also used to unequivocal {sup 1}H and {sup 13}C chemical shift assignments of alkaloids. The ethanolic extract of roots, alkaloidic and no-alkaloidic fractions and iso-voacristine hydroxyindolenine and voacangine were evaluated for their antioxidative properties using an autographic assay based on {beta}-carotene bleaching on TLC plates, and also spectrophotometric detection by reduction of the stable DPPH (2,2-diphenyl-1-picrylhydrazyl) free radical. (author)

  2. Response of marine copepods to a changing tropical environment: winners, losers and implications.

    Science.gov (United States)

    Chew, Li Lee; Chong, Ving Ching

    2016-01-01

    Background. Climate change concurrent with anthropogenic disturbances can initiate serial changes that reverberate up the food chain with repercussions for fisheries. To date, there is no information available concerning the combined effects of global warming and human impacts on tropical marine food webs. While temperate copepods respond differently to warming and environmental stressors, the extent to which tropical copepods can adapt to rising temperature of already warm waters remains unknown. We hypothesize that sea warming and other anthropogenic disturbances over the long term will have the greatest impact on the copepod community in nearshore waters where their effects are accentuated, and therefore vulnerable and resilient species could be identified. Methods. Zooplankton samples were collected during two time periods (1985-86 and 2014-15) interposed by marked anthropogenic disturbances, and at the same five stations located progressively from inshore to offshore in Klang Strait, Malaysia, following the asymmetrical before-after-control-impact (BACI) design. Copepods were identified to species, and results were interpreted by univariate (ANOVA) and multivariate (PERMANOVA, PCO) analyses of the computed species abundance and diversity measures. Results. Copepod total abundance was not significantly different among stations but higher after disturbance than before disturbance. However, changes in the abundance of particular species and the community structure between time periods were dramatic. Coastal large-bodied calanoid species (e.g., Acartia spinicauda, Calanopia thompsoni, Pseudodiaptomus bowmani and Tortanus forcipatus) were the most vulnerable group to disturbance. This however favored the opportunistic species (e.g., Oithona simplex, O. attenuata, Hemicyclops sp., Pseudomacrochiron sp. and Microsetella norvegica). Small-bodied copepods (e.g., Paracalanus sp., Parvocalanus crassirostris and Euterpina acutifrons) were unaffected. Centropages

  3. Response of marine copepods to a changing tropical environment: winners, losers and implications

    Directory of Open Access Journals (Sweden)

    Li Lee Chew

    2016-05-01

    Full Text Available Background. Climate change concurrent with anthropogenic disturbances can initiate serial changes that reverberate up the food chain with repercussions for fisheries. To date, there is no information available concerning the combined effects of global warming and human impacts on tropical marine food webs. While temperate copepods respond differently to warming and environmental stressors, the extent to which tropical copepods can adapt to rising temperature of already warm waters remains unknown. We hypothesize that sea warming and other anthropogenic disturbances over the long term will have the greatest impact on the copepod community in nearshore waters where their effects are accentuated, and therefore vulnerable and resilient species could be identified. Methods. Zooplankton samples were collected during two time periods (1985–86 and 2014–15 interposed by marked anthropogenic disturbances, and at the same five stations located progressively from inshore to offshore in Klang Strait, Malaysia, following the asymmetrical before-after-control-impact (BACI design. Copepods were identified to species, and results were interpreted by univariate (ANOVA and multivariate (PERMANOVA, PCO analyses of the computed species abundance and diversity measures. Results. Copepod total abundance was not significantly different among stations but higher after disturbance than before disturbance. However, changes in the abundance of particular species and the community structure between time periods were dramatic. Coastal large-bodied calanoid species (e.g., Acartia spinicauda, Calanopia thompsoni, Pseudodiaptomus bowmani and Tortanus forcipatus were the most vulnerable group to disturbance. This however favored the opportunistic species (e.g., Oithona simplex, O. attenuata, Hemicyclops sp., Pseudomacrochiron sp. and Microsetella norvegica. Small-bodied copepods (e.g., Paracalanus sp., Parvocalanus crassirostris and Euterpina acutifrons were unaffected

  4. Study on the Heavy Metal Bioconcentrations of the Shadegan International Wetland Mosquitofish, Gambusia Affinis, by Inductively Coupled Plasma Technique

    Directory of Open Access Journals (Sweden)

    Hassan Nasirian

    2013-07-01

    Full Text Available The purpose of this study was to evaluate the levels of heavy metal bioconcentration of the mosquitofish (Gambusia affinis in Shadegan international wetland. Sampling including the water, waterbed sediment and mosquitofish was carried out from the selected sampling sites during October and November 2011, and analyzed by the ICP-OES. Results show that the water has poor qualitative condition, according to EPA and WHO water quality standards. The level of the water Cr in the selected sites in both months and the levels of Fe, Mn and Zn during October in the SW1 site were higher than the instrumental detection limits indicating that the water was contaminated with these metals in the mentioned sites and months. The levels of the waterbed sediment As, Co, Cr, Cu, Fe, Mn, Pb and Zn, and mosquitofish Cr, Cu, Fe, Mn, Zn, Co and Cd were much higher than the instrumental detection limits, indicating that the waterbed sediment and mosquitofish were contaminated with them during October and November in the selected sites. Statistical assessments reveal that there is a significant difference between the mentioned contaminated water, waterbed sediment and mosquitofish heavy metals (all P-values < 0.05. In overall, it is considered that the contaminated heavy metals can be accumulated in the waterbed sediment and bioconcentrated in the wildlife tissues, then finally can be entered in the marine food chains and biomagnified there after long periods. In conclusion, this paper confirmed that the G. affinis can be used as a bioindicator of heavy metal pollution in marine ecosystems such as wetlands

  5. Mandibular gnathobases of marine planktonic copepods – feeding tools with complex micro- and nanoscale composite architectures

    Directory of Open Access Journals (Sweden)

    Jan Michels

    2015-03-01

    Full Text Available Copepods are dominant members of the marine zooplankton. Their diets often comprise large proportions of diatom taxa whose silicified frustules are mechanically stable and offer protection against grazers. Despite of this protection, many copepod species are able to efficiently break even the most stable frustule types. This ability requires specific feeding tools with mechanically adapted architectures, compositions and properties. When ingesting food, the copepods use the gnathobases of their mandibles to grab and, if necessary, crush and mince the food items. The morphology of these gnathobases is related to the diets of the copepods. Gnathobases of copepod species that mainly feed on phytoplankton feature compact and stable tooth-like structures, so-called teeth. In several copepod species these gnathobase teeth have been found to contain silica. Recent studies revealed that the siliceous teeth are complex microscale composites with silica-containing cap-like structures located on chitinous exoskeleton sockets that are connected with rubber-like bearings formed by structures with high proportions of the soft and elastic protein resilin. In addition, the silica-containing cap-like structures exhibit a nanoscale composite architecture. They contain some amorphous silica and large proportions of the crystalline silica type α-cristobalite and are pervaded by a fine chitinous fibre network that very likely serves as a scaffold during the silicification process. All these intricate composite structures are assumed to be the result of a coevolution between the copepod gnathobases and diatom frustules in an evolutionary arms race. The composites very likely increase both the performance of the siliceous teeth and their resistance to mechanical damage, and it is conceivable that their development has favoured the copepods’ dominance of the marine zooplankton observed today.

  6. Characterization and analysis of ribosomal proteins in two marine calanoid copepods

    Science.gov (United States)

    Yang, Feifei; Xu, Donghui; Zhuang, Yunyun; Huang, Yousong; Yi, Xiaoyan; Chen, Hongju; Liu, Guangxing; Zhang, Huan

    2016-11-01

    Copepods are among the most abundant and successful metazoans in the marine ecosystem. However, genomic resources related to fundamental cellular processes are still limited in this particular group of crustaceans. Ribosomal proteins are the building blocks of ribosomes, the primary site for protein synthesis. In this study, we characterized and analyzed the cDNAs of cytoplasmic ribosomal proteins (cRPs) of two calanoid copepods, Pseudodiaptomus poplesia and Acartia pacifica. We obtained 79 cRP cDNAs from P. poplesia and 67 from A. pacifica by cDNA library construction/sequencing and rapid amplification of cDNA ends. Analysis of the nucleic acid composition showed that the copepod cRP-encoding genes had higher GC content in the protein-coding regions (CDSs) than in the untranslated regions (UTRs), and single nucleotide repeats (>3 repeats) were common, with "A" repeats being the most frequent, especially in the CDSs. The 3'-UTRs of the cRP genes were significantly longer than the 5'-UTRs. Codon usage analysis showed that the third positions of the codons were dominated by C or G. The deduced amino acid sequences of the cRPs contained high proportions of positively charged residues and had high pI values. This is the first report of a complete set of cRP-encoding genes from copepods. Our results shed light on the characteristics of cRPs in copepods, and provide fundamental data for further studies of protein synthesis in copepods. The copepod cRP information revealed in this study indicates that additional comparisons and analysis should be performed on different taxonomic categories such as orders and families.

  7. Distribution of Arctic and Pacific copepods and their habitat in the northern Bering Sea and Chukchi Sea

    Science.gov (United States)

    Sasaki, H.; Matsuno, K.; Fujiwara, A.; Onuka, M.; Yamaguchi, A.; Ueno, H.; Watanuki, Y.; Kikuchi, T.

    2015-11-01

    The advection of warm Pacific water and the reduction of sea-ice extent in the western Arctic Ocean may influence the abundance and distribution of copepods, i.e., a key component in food webs. To understand the factors affecting abundance of copepods in the northern Bering Sea and Chukchi Sea, we constructed habitat models explaining the spatial patterns of the large and small Arctic copepods and the Pacific copepods, separately, using generalized additive models. Copepods were sampled by NORPAC net. Vertical profiles of density, temperature and salinity in the seawater were measured using CTD, and concentration of chlorophyll a in seawater was measured with a fluorometer. The timing of sea-ice retreat was determined using the satellite image. To quantify the structure of water masses, the magnitude of pycnocline and averaged density, temperature and salinity in upper and bottom layers were scored along three axes using principal component analysis (PCA). The structures of water masses indexed by the scores of PCAs were selected as explanatory variables in the best models. Large Arctic copepods were abundant in the water mass with high salinity water in bottom layer or with cold/low salinity water in upper layer and cold/high salinity water in bottom layer, and small Arctic copepods were abundant in the water mass with warm/saline water in upper layer and cold/high salinity water in bottom layers, while Pacific copepods were abundant in the water mass with warm/saline in upper layer and cold/high salinity water in bottom layer. All copepod groups were abundant in areas with deeper depth. Although chlorophyll a in upper and bottom layers were selected as explanatory variables in the best models, apparent trends were not observed. All copepod groups were abundant where the sea-ice retreated at earlier timing. Our study might indicate potential positive effects of the reduction of sea-ice extent on the distribution of all groups of copepods in the Arctic Ocean.

  8. Use of the copepod Oithona hebes as a bioencapsulator of essential fatty acids

    Directory of Open Access Journals (Sweden)

    Marcia Vanacor Barroso

    2015-09-01

    Full Text Available AbstractThe advantages of using copepods in aquaculture include nutritional superiority, high digestibility and broad spectrum of sizes, with the possibility of bioencapsulation of nutrients, probiotics and medicines. This study aimed to compare the effects of feeding copepods with a microalgae diet and two commercial inert diets on the copepod culture performance and their fatty acid profile. Wild copepods were collected in the estuarine system of Piraquê-açu River, Aracruz, Espírito Santo, Brazil, with a conical net of 60 cm in diameter and 200 μm mesh with a blind cup end, towed through the subsurface layer at a speed of 1 knot for 5 minutes. Once collected, the material was sieved in order to select only Oithona hebes. The experiment was conducted in nine cylindrical-conical tanks with a 60 L capacity, salinity of 25.8 ± 1.3, temperature of 25.5 ± 0.5 ºC and weak aeration, stocked with a density of 1.5 copepod/mL. Treatments were made in triplicate and consisted of: Treatment 1 (Control fed with microalgae Chaetoceros gracilis and Nannochloropsis oculata (1:1 with 50,000 cells.mL-1each; Treatment 2 with S.Parkle® INVE (1g.million-1; and Treatment 3 with freeze-dried spirulina (1g.million-1. The mean final population was compared by a Tukey test (p < 0.05. Results showed higher population growth for copepods treated with S.parkle, which was the only treatment that presented copepodites. S.parkle was a good source of total lipids (9.54 g.100g-1 dry weight, high availability of DHA, EPA and had a good DHA:EPA:ARA ratio of 12.4:3.4:1.0. Copepods that were fed S.parkle had the highest DHA levels and a DHA:EPA:ARA ratio of 15.4:2.2:1.0. This study showed that S.parkle is a good inert food for rearing the copepod O. hebes, demonstrating the ability of copepods to bioencapsulate nutrients, allowing their transfer in the food chain.

  9. Impacts of ontogenetically migrating copepods on downward carbon flux in the western subarctic Pacific Ocean

    Science.gov (United States)

    Kobari, Toru; Steinberg, Deborah K.; Ueda, Ai; Tsuda, Atsushi; Silver, Mary W.; Kitamura, Minoru

    2008-07-01

    To evaluate the impacts of ontogenetically (seasonally) migrating copepods on carbon transport to the mesopelagic zone, we investigated depth distribution, population structure, and feeding activity of the ontogentic copepod community in the western subarctic Pacific Ocean from day-night pairs of zooplankton samples down to 1000 m during the VERtical Transport In the Global Ocean (VERTIGO) program. Over the 31 July-16 August 2005 study period, the biomass of Neocalanus cristatus and Neocalanus plumchrus predominated in the near surface waters, while Neocalanus flemingeri was already dormant at depth. We observed a strong diel migration for Metridia pacifica, and a seasonal downward migration for Eucalanus bungii. Based on gut pigment analysis, ingestion rate of the copepod community was 214-375 mg C m -2 day -1, which was equal to 26-37% of the concurrent primary production. However, comparison of grazing estimated from gut pigments to calculated carbon demand of the copepod community indicates that phytoplankton comprised 37-59% of the ingested carbon. Thus, the copepod community appears to have also relied on detritus and microzooplankton for their nutrition, likely because primary production during this time was dominated by picophytoplankton too small to be grazed by these large copepods. Fecal pellet flux by the copepod community was estimated to account for 141-223% of the sedimentary particulate organic carbon (POC) flux at 150 m, suggesting considerable fragmentation and consumption of pellets in the upper layers. Fecal pellets alone were adequate to meet copepod carbon demand in the surface 0-150 m layer. Active carbon flux by diel migration of M. pacifica (respiration, egestion, and mortality) was 4-17 mg C m -2 day -1, equal to 6-44% of sedimentary POC flux at 150 m. Active carbon flux by N. flemingeri ontogenetic migration (i.e., respiration and mortality at depth) contributed 246 mg C m -2 year -1, equal to 9% of sedimentary POC flux at 1000 m. The

  10. Effects of elevated pH on marine copepods in mass cultivation systems

    DEFF Research Database (Denmark)

    Hansen, Benni Winding; Hansen, Per Juel; Nielsen, Torkel Gissel

    2017-01-01

    -neritic distribution, O. similis, exhibited 72 h LC50 at pH 8.39 ± 0.11 (±95% CL) whereas the most estuarine E. affinis had LC50 at pH 9.51 ± 0.04. The rest had LC50 at intermediary pH's. Egg hatching by a selection of species, Acartia spp., C. typicus and E. affinis, was unaffected by pH up to 9.0–9.5. Nauplii from...... both Acartia spp. and C. typicus had higher mortality at pH 9.5 than at the other pH regimes while E. affinis nauplii were not affected by pH. Wild Acartia spp. and A. tonsa from a culture showed some differences in response although of minor practical importance for aquaculture; both produced no eggs...... at pH 9.5, A. tonsa exhibited significantly higher egg production at all other pH's than 9.5, both showed egg hatching invariant of pH, but gradually increasing nauplii mortality with pH. We suggest active/passive selection to obtain the most pH robust species able to cope with accidently...

  11. Copepod Behavior in ``Cryptic Blooms'' of Toxic Algae

    Science.gov (United States)

    True, A. C.; Webster, D. R.; Weissburg, M. J.; Yen, J.

    2014-11-01

    Copepods,Acartia tonsa and Temora longicornis, were exposed to thin layers of exudates from the toxic dinoflagellate Karenia brevis (1 - 10,000 cells/mL) (i.e. models of ``cryptic blooms'' of toxic phytoplankton). Planar laser-induced fluorescence (PLIF) was used to quantify the spatiotemporal structure of the layer allowing for correlation of behavioral responses with toxin levels. Both species explicitly avoided the exudate layer and the vicinity of the layer. Measures of path kinematics (swimming speed, turn frequency) by location (in-layer vs. out-of-layer) and exposure (pre-contact vs. post-contact) revealed some similarities, but also significant differences, in trends for each species. A. tonsa significantly increases swimming speed and swimming speed variability in the exudate layer and post-contact, whereas T. longicornis slightly increases both in-layer and slightly reduces both post-contact. Both species increase turn frequency in-layer and post-contact with increasing K. brevis exudate concentration. Path fracticality indicates that A. tonsatrajectories became more diffuse/sinuous and T. longicornis trajectories became more linear/ballistic (trending effects). Regression analyses revealed that the rate of change of behavior with increasing exudate concentration for A. tonsa was thrice to fifty times that of T. longicornis. Toxic K. brevis can essentially eliminate top-down grazer control ,another sinister means by which it gains a competitive advantage over the local phytoplankton taxa.

  12. Spatial distribution of copepods along the salinity gradient of Perai river estuary, Penang, Malaysia.

    Science.gov (United States)

    Johan, I; Maznah, W O Wan; Mashhor, M; Abu Hena, M K; Amin, S M N

    2012-07-01

    Investigation on copepod communities in Perai river estuary was conducted from November 2005 to May 2006. Five stations were established for monthly sampling and were located from the river mouth to the upper reaches of the river. Copepod samples were collected from vertical tows using a standard zooplankton net. The Perai river estuary was slightly stratified and salinity decreases significantly from the mouth of the river towards the upper reaches of the river. A total of 28 species of copepods were recorded and comprised of 14 families, Paracalanidae, Oithonidae, Corycaeidae, Acartiidae, Calanidae, Centropagidae, Eucalanidae, Pontellidae, Pseudodiaptomidae, Tortanidae, Ectinosomatidae, Euterpinidae, Clausidiidae and Cyclopidae. A total of 10 species showed high positive affiliation towards salinity (R > 0.60), Acartia spinicauda, Euterpina acutifrons, Microsetella norvegica, Oithona nana, Oithona simplex, Paracalanus crassirostris, Paracalanus elegans, Paracalanus parvus, Pseudodiaptomus sp. and Hemicyclops sp. The copepod species Pseudodiaptomus dauglishi were negatively affiliated towards salinity (R = -0.71). The copepod assemblages classified into two distinct groups according to salinity regimes, euryhaline-polyhaline group (25 marine affiliated species) and oligohaline-mesohaline group (3 freshwater affiliated species).

  13. Hydrodynamic and Sensory Factors Governing Response of Copepods to Simulated Predation by Balaenid Whales

    Directory of Open Access Journals (Sweden)

    Alexander J. Werth

    2012-01-01

    Full Text Available Predator/prey interactions between copepods and balaenid (bowhead and right whales were studied with controlled lab experiments using moving baleen in still water and motionless baleen in flowing water to simulate zooplankton passage toward, into, and through the balaenid oral cavity. Copepods showed a lesser escape response to baleen and to a model head simulating balaenid oral hydrodynamics than to other objects. Copepod escape response increased as water flow and body size increased and was greatest at distances ≥10 cm from baleen and at copepod density = 10,000 m−3. Data from light/dark experiments suggest that escape is based on mechanoreception, not vision. The model head captured 88% of copepods. Results support previous research showing hydrodynamic effects within a whale’s oral cavity create slight suction pressures to draw in prey or at least preclude formation of an anterior compressive bow wave that could scatter or alert prey to the presence of the approaching whale.

  14. Climate change affects low trophic level marine consumers: warming decreases copepod size and abundance.

    Science.gov (United States)

    Garzke, Jessica; Ismar, Stefanie M H; Sommer, Ulrich

    2015-03-01

    Concern about climate change has re-ignited interest in universal ecological responses to temperature variations: (1) biogeographical shifts, (2) phenology changes, and (3) size shifts. In this study we used copepods as model organisms to study size responses to temperature because of their central role in the pelagic food web and because of the ontogenetic length constancy between molts, which facilitates the definition of size of distinct developmental stages. In order to test the expected temperature-induced shifts towards smaller body size and lower abundances under warming conditions, a mesocosm experiment using plankton from the Baltic Sea at three temperature levels (ambient, ambient +4 °C, ambient -4 °C) was performed in summer 2010. Overall copepod and copepodit abundances, copepod size at all life stages, and adult copepod size in particular, showed significant temperature effects. As expected, zooplankton peak abundance was lower in warm than in ambient treatments. Copepod size-at-immature stage significantly increased in cold treatments, while adult size significantly decreased in warm treatments.

  15. Pontellid copepods, Labidocera spp., affected by ocean acidification: A field study at natural CO2 seeps.

    Science.gov (United States)

    Smith, Joy N; Richter, Claudio; Fabricius, Katharina E; Cornils, Astrid

    2017-01-01

    CO2 seeps in coral reefs were used as natural laboratories to study the impacts of ocean acidification on the pontellid copepod, Labidocera spp. Pontellid abundances were reduced by ∼70% under high-CO2 conditions. Biological parameters and substratum preferences of the copepods were explored to determine the underlying causes of such reduced abundances. Stage- and sex-specific copepod lengths, feeding ability, and egg development were unaffected by ocean acidification, thus changes in these physiological parameters were not the driving factor for reduced abundances under high-CO2 exposure. Labidocera spp. are demersal copepods, hence they live amongst reef substrata during the day and emerge into the water column at night. Deployments of emergence traps showed that their preferred reef substrata at control sites were coral rubble, macro algae, and turf algae. However, under high-CO2 conditions they no longer had an association with any specific substrata. Results from this study indicate that even though the biology of a copepod might be unaffected by high-CO2, Labidocera spp. are highly vulnerable to ocean acidification.

  16. The effect of Fucus vesiculosus on the grazing of harpacticoid copepods on diatom biofilms

    Science.gov (United States)

    De Troch, M.; Chepurnov, V. A.; Vincx, M.; Ólafsson, E.

    2008-10-01

    The effect of Fucus vesiculosus on the functional traits of three harpacticoid copepod species ( Tigriopus brevicornis, Paramphiascella fulvofasciata and Microarthridion littorale) was studied. These copepods are likely to be important grazers on biofilms consisting mainly of diatoms. Several microcosms were created using diatom cultures ( Navicula phyllepta and Seminavis robusta) and vegetative thalli of Fucus, with the biofilm associated, collected from the field. The diatoms were enriched in the stable carbon 13C to facilitate tracing in the harpacticoids. The biofilm on the Fucus was labeled through impregnation of the Fucus leaves in 13C enriched seawater. In all treatments a measurable uptake of diatoms was found for the three copepod species. All copepods showed a low uptake of labeled material when only Fucus thalli were available. The grazing on the benthic diatoms was negatively affected by the presence of the Fucus thalli in the case of P. fulvofasciata. One species, T. brevicornis, grazed efficiently both on sedimentary and epiphytic biofilms. We hereby proved experimentally that benthic harpacticoid copepods are able to switch their food uptake under different habitat/food circumstances. This variety of food uptake is an illustration of the so-called 'niche complementarity effect' that lies at the basis of diverse communities.

  17. Presencia de Gambusia affinis (Baird & Girard, 1853 en un humedal boscoso del Sur de Chile. Posibles implicancias sobre la fauna local de invertebrados.

    Directory of Open Access Journals (Sweden)

    L. Parra-Coloma

    2014-03-01

    Full Text Available Las especies invasoras son la principal causa de pérdida debiodiversidad del planeta, producto de la depredación que afecta a la faunalocal mediante competencia, hibridación, alteración del hábitat y transmisiónde enfermedades. En este estudio se describe la posible implicancia del pezmosquito sobre la fauna de invertebrados en un humedal boscoso presente en laregión de la Araucanía, Chile. Los resultados nos indican la presencia de Gambusia affinis en todos los sitios demuestreo, destacándose su gran adaptabilidad a la temperatura y pH. El roldepredador de Gambusia affinis sobremosquitos, puede favorecer al desarrollo de sus larvas, al consumirinvertebrados predadores de éstas, influyendo en la estructura trófica de lascomunidades.

  18. Seasonal variation and longitudinal distribution of copepods in the main river area of the Three Gorges Reservoir

    Institute of Scientific and Technical Information of China (English)

    Jianliang YAO; Junzeng XUE; Dengyuan WANGt; Qinghua CAI; Xiangfei HUANG; Jiankang LIU

    2008-01-01

    The ecosystem of the Three Gorges in the Yangtze River was changed into an artificial lake (res-ervoir) ecosystem after impoundment in June 2003. We surveyed the seasonal variation and spatial distribution of copepods from April 2004 to January 2005 in order to provide data for clarifying the successional pattern of the ecosystem. From Jiangjin to Maoping, eight copepod species were collected and classified into Calanoida (2), Harpacticoida (1), and Cyclopoida (5). Among them, Mesocyclops pehpeiensis, M. leuckarti and Sinocalanus dorrii had a relatively wide distribution. No distinct dif-ference in species number was found among the sampling sites, but the species composition was different. Species composition, distribution and density of copepods showed significant seasonal variations. In addition, cope-pod density showed an obvious gradient with the distance from the reservoir dam: the nearer to the dam, the denser the copepods.

  19. Physiological response of the intertidal copepod Tigriopus japonicus experimentally exposed to cadmium

    Directory of Open Access Journals (Sweden)

    Emadeldeen H. Mohammed

    2011-01-01

    Full Text Available The intertidal harpacticoid copepod Tigriopus japonicus is a benthic copepod and has beencommonly used in ecotoxicology and environmental genomics studies as a marine model species. In thisstudy, Laboratory experiments were conducted to investigate the effects of cadmium (Cd on survival,development, growth and reproductive performance of T.japonicus. Our results indicated that Cd wassignificantly affected adult survival and development, but not those of nauplii. Despite the reduction inadult female total body length, Cd was not significantly affected copepod growth. Concerning T.japonicusreproduction response, Cd was significantly reduced the number of nauplii produced at 10 μg L-1. Thus,survival, development and reproduction in T.japonicus as a model test species could be effectivephysiological markers to monitor marine metal pollution and to assess population response.

  20. Sex, sex-ratios, and the dynamics of pelagic copepod populations

    DEFF Research Database (Denmark)

    Kiørboe, Thomas

    2006-01-01

    within this group. Winter population sizes are well predicted by the critical density required for population persistence which, in turn, is closely related to the body-size-dependent mate-search capacity. Thus, the different requirements for mating lead in the first case to a more opportunistic......I examine how the population biology of pelagic copepods depends on their mating biology using field data and a simple demographic model. Among calanoid copepods, two distinct patterns emerge. Firstly, copepods that lack seminal receptacle and require repeated mating to stay fertilized have near...... equal adult sex ratios in field populations. Winter population densities are orders of magnitude less than the critical population density required for population persistence, but populations survive winter seasons as resting eggs in the sediment. Population growth in these species is potentially high...

  1. Feeding on copepod fecal pellets: a new trophic role of dinoflagellates as detritivores

    DEFF Research Database (Denmark)

    Poulsen, Louise K.; Moldrup, M.; Berge, T.;

    2011-01-01

    Recent field studies indicate that dinoflagellates are key degraders of copepod fecal pellets. This study is the first to publish direct evidence of pellet grazing by dinoflagellates. Feeding and growth on copepod fecal pellets were studied for both heterotrophic (4 species) and mixotrophic...... dinoflagellates (3 species) using a combination of classic incubation experiments and video recordings of feeding behavior. Fecal pellets were produced by adult Acartia tonsa feeding on Rhodomonas salina. Two mixotrophic species (Karlodinium armiger, a gymnodinoid dinoflagellate, Gy1) and all heterotrophic...... dinoflagellates (Gyrodinium dominans, Gyrodinium spirale, Diplopsalis lenticula, Protoperidinium depressum) studied fed on fecal pellets. Using natural concentrations of dinoflagellates and copepod fecal pellets, average ingestion rates of 0.2 and 0.1 pellets cell−1 d−1 and clearance rates of between 0.2 and 0...

  2. Combined Effects of Ocean Warming and Acidification on Copepod Abundance, Body Size and Fatty Acid Content.

    Directory of Open Access Journals (Sweden)

    Jessica Garzke

    Full Text Available Concerns about increasing atmospheric CO2 concentrations and global warming have initiated studies on the consequences of multiple-stressor interactions on marine organisms and ecosystems. We present a fully-crossed factorial mesocosm study and assess how warming and acidification affect the abundance, body size, and fatty acid composition of copepods as a measure of nutritional quality. The experimental set-up allowed us to determine whether the effects of warming and acidification act additively, synergistically, or antagonistically on the abundance, body size, and fatty acid content of copepods, a major group of lower level consumers in marine food webs. Copepodite (developmental stages 1-5 and nauplii abundance were antagonistically affected by warming and acidification. Higher temperature decreased copepodite and nauplii abundance, while acidification partially compensated for the temperature effect. The abundance of adult copepods was negatively affected by warming. The prosome length of copepods was significantly reduced by warming, and the interaction of warming and CO2 antagonistically affected prosome length. Fatty acid composition was also significantly affected by warming. The content of saturated fatty acids increased, and the ratios of the polyunsaturated essential fatty acids docosahexaenoic- (DHA and arachidonic acid (ARA to total fatty acid content increased with higher temperatures. Additionally, here was a significant additive interaction effect of both parameters on arachidonic acid. Our results indicate that in a future ocean scenario, acidification might partially counteract some observed effects of increased temperature on zooplankton, while adding to others. These may be results of a fertilizing effect on phytoplankton as a copepod food source. In summary, copepod populations will be more strongly affected by warming rather than by acidifying oceans, but ocean acidification effects can modify some temperature impacts.

  3. Combined Effects of Ocean Warming and Acidification on Copepod Abundance, Body Size and Fatty Acid Content

    Science.gov (United States)

    Hansen, Thomas; Ismar, Stefanie M. H.; Sommer, Ulrich

    2016-01-01

    Concerns about increasing atmospheric CO2 concentrations and global warming have initiated studies on the consequences of multiple-stressor interactions on marine organisms and ecosystems. We present a fully-crossed factorial mesocosm study and assess how warming and acidification affect the abundance, body size, and fatty acid composition of copepods as a measure of nutritional quality. The experimental set-up allowed us to determine whether the effects of warming and acidification act additively, synergistically, or antagonistically on the abundance, body size, and fatty acid content of copepods, a major group of lower level consumers in marine food webs. Copepodite (developmental stages 1–5) and nauplii abundance were antagonistically affected by warming and acidification. Higher temperature decreased copepodite and nauplii abundance, while acidification partially compensated for the temperature effect. The abundance of adult copepods was negatively affected by warming. The prosome length of copepods was significantly reduced by warming, and the interaction of warming and CO2 antagonistically affected prosome length. Fatty acid composition was also significantly affected by warming. The content of saturated fatty acids increased, and the ratios of the polyunsaturated essential fatty acids docosahexaenoic- (DHA) and arachidonic acid (ARA) to total fatty acid content increased with higher temperatures. Additionally, here was a significant additive interaction effect of both parameters on arachidonic acid. Our results indicate that in a future ocean scenario, acidification might partially counteract some observed effects of increased temperature on zooplankton, while adding to others. These may be results of a fertilizing effect on phytoplankton as a copepod food source. In summary, copepod populations will be more strongly affected by warming rather than by acidifying oceans, but ocean acidification effects can modify some temperature impacts. PMID:27224476

  4. Induction of domoic acid production in the toxic diatom Pseudo-nitzschia seriata by calanoid copepods

    DEFF Research Database (Denmark)

    Tammilehto, Anna; Nielsen, Torkel Gissel; Krock, B.

    2015-01-01

    in the presence ofthe copepods. This response was chemically mediated without physical contact between the organismssuggesting that it was induced by potential waterborne cues from the copepods or changes in waterchemistry. Domoic acid production may be related to defense against grazing in P. seriata although...... it wasnot shown in the present study. To evaluate if the induction of domoic acid production was mediatedby the chemical cues from damaged P. seriata cells, live P. seriata cells were exposed to a P. seriata cellhomogenate, but no effect was observed. Chain formation in P. seriata was affected only when...

  5. Use of phytoplankton pigments in estimating food selection of three marine copepods

    DEFF Research Database (Denmark)

    Oechsler-Christensen, B.; Jonasdottir, Sigrun; Henriksen, P.

    2012-01-01

    . Traditional grazing experiments were carried out in parallel with pigment analysis in experiments where the copepod A. tonsa was exposed to a mixture of food organisms. The results demonstrated that the two methods gave similar results with regard to food selection and that with certain precautions, pigment......Experiments were carried out to test the use of algal pigments in zooplankton grazing studies with a special emphasis on estimation of food selection. The results demonstrated that pigment composition of the phytoplankton food was reflected closely in the three copepod species Centropages typicus...... analysis can be successfully used in food selection studies...

  6. Miocene cyclopid copepod from a saline paleolake in Mojave, California

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    Maria Hołyńska

    2016-06-01

    Full Text Available There are remarkably few direct fossil records of Copepoda, which implies that current estimates of the lineage divergence times and inferences on the historical biogeography remain highly dubious for these small-sized crustaceans. The Cyclopidae, a predominantly freshwater copepod family with 1000+ species and distributed worldwide, has no fossil record at all. Recent collections from the middle Miocene Barstow Formation in Southern California resulted in ample material of finely preserved cyclopid fossils, including both adult and larval stages. To document the antennulary setation pattern in the adult and copepodid instars we used a coding system that is coherent between sexes and developmental stages. The majority of the cyclopid fossils, coming from saline lake environment, represent the modern genus Apocyclops, a euryhaline, thermophilic group occurring both in the New World and Old World. A new species Apocyclops californicus is described, based on the short medial spine and spiny ornamentation of the free segment of leg 5, spinule ornamentation of pediger 5, and well-developed protuberances of the intercoxal sclerite of leg 4. The presence of antennal allobasis and the features of the swimming legs unambiguously place the Miocene Apocyclops in the A. panamensis-clade, a predominantly amphi-Pacific group. The middle Miocene fossils with clear affinities to a subgroup of Apocyclops imply an early Miocene or Paleogene origin of the genus. Based on the geographic patterns of the species richness and morphology in Apocyclops and its presumed closest relative, genus Metacyclops, we hypothesize that: (i the ancestor of Apocyclops, similar in morphology to some cave-dweller Metacyclops occurring today in the peri-Mediterranean region, might have arrived in North America from Europe via the Thulean North Atlantic bridge in the late Paleocene–early Eocene; (ii Eocene termination of the Thulean land connection might have resulted in the

  7. Tumour-like anomaly of copepods-an evaluation of the possible causes in Indian marine waters.

    Science.gov (United States)

    Jagadeesan, L; Jyothibabu, R

    2016-04-01

    Globally, tumour-like anomalies (TLA) in copepods and the critical assessment of their possible causes are rare. The exact causative factor and ecological consequences of TLA in copepods are still unclear and there is no quantitative data available so far to prove conclusively the mechanism involved in developing TLA in copepods. TLA in copepods are considered as a potential threat to the well-being of the aquatic food web, which prompted us to assess these abnormalities in Indian marine waters and assess the possible etiological agents. We carried out a focused study on copepods collected from 10 estuarine inlets and five coastal waters of India using a FlowCAM, advanced microscopes and laboratory-incubated observations. The analysis confirmed the presence of TLA in copepods with varying percentage of incidence in different environments. TLA was recorded in 24 species of copepods, which constituted ~1-15 % of the community in different environments. TLA was encountered more frequently in dominant copepods and exhibited diverse morphology; ~60 % was round, dark and granular, whereas ~20 % was round/oval, transparent and non-granular. TLA was mostly found in the dorsal and lateral regions of the prosome of copepods. The three suggested reasons/assumptions about the causes of TLA such as ecto-parasitism (Ellobiopsis infection), endo-parasitism (Blastodinium infection) and epibiont infections (Zoothamnium and Acineta) were assessed in the present study. We did find infections of endo-parasite Blastodinium, ecto-parasite Ellobiopsis and epibiont Zoothamnium and Acineta in copepods, but these infectious percentages were found <1.5 % to the total density and most of them are species specific. Detailed microscopical observations of the samples collected and the results of the incubation experiments of infected copepods revealed that ecto-parasitism, endo-parasitism and epibiont infections have less relevance to the formation of TLA in copepods. On the other hand

  8. Weather-induced mass deaths of the Common House Swift Apus affinis in Thengumarahada Village of the Nilgiris, southern India

    Directory of Open Access Journals (Sweden)

    B. Ramakrishnan

    2013-12-01

    Full Text Available Weather influences all living organisms, especially wild animals. In the case of birds, inclement weather conditions may affect them during migration and feeding that could cause mass mortality in the same species or many related species. This paper describes an incidence of mass deaths of the Common House Swift Apus affinis at Thengumarahada Village of Nilgiris, Tamil Nadu, southern India during February 2008. The samples of the dead birds were sent for toxicological and bacteriological examination at Southern Regional Disease Diagnostic Laboratory, Bangalore. Spot post mortems were also conducted by forest veterinarians. Results of the diagnostic analysis revealed that mass mortality might be due to extreme weather conditions leading to acute dehydration, shock and death. The postmortem reports say that the crop and the gastro intestinal tract (GI were found empty in all the cases, suggesting starvation. We thus conclude that unseasonal heavy rains and non availability of food could have led to hypothermia and starvation of birds over a long period resulting in mass mortality.

  9. Physiological responses and gene expression changes in the western mosquitofish (Gambusia affinis) exposed to progesterone at environmentally relevant concentrations.

    Science.gov (United States)

    Hou, Liping; Xu, Hongyan; Ying, Guangguo; Yang, Yang; Shu, Hu; Zhao, Jianliang; Cheng, Xuemei

    2017-09-14

    Progesterone (P4) is a natural and synthetic steroid, widely distributed in the aquatic environments. It can lead to adverse effects on the endocrine system in aquatic organisms. This study investigated the toxicological effects of exposure to environmentally relevant concentrations (4, 44, and 410ng/L) of progesterone for 42 d on adult female mosquitofish, Gambusia affinis. We performed morphological and histological analyses on gonads, anal fins, liver, and gills after the exposure of mosquito fish to P4. The expression levels of genes (vtg, er, and ar isoforms) related to fish reproduction and detoxification (cyp1a) in the liver were quantified by quantitative real-time polymerase chain reaction. The results showed that the progesterone exposure induced slight masculinization in female mosquitofish, influenced the oocyte maturation as revealed by histology of the ovaries, and caused severe damages to the liver and gills of adult female mosquitofish. It also suppressed the mRNAs expression of vtg, er, cyp1a, and significantly enhanced the expression of ar mRNA in the liver. This study reveals the molecular and physiological effects of progesterone at environmentally relevant concentrations, which might further be translated to alterations in the reproduction of mosquitofish. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Reproductive plasticity of Hypostomus affinis (Siluriformes: Loricariidae as a mechanism to adapt to a reservoir with poor habitat complexity

    Directory of Open Access Journals (Sweden)

    Silvana Duarte

    2011-10-01

    Full Text Available In this work we describe the gonad morphology and spawning season of Hypostomus affinis (Steindachner, 1877 in a tropical reservoir based on 55 males and 125 females. Our aim was to assess eventual adaptations in reproductive tactics developed by this riverine species inhabiting an oligotrophic reservoir with low habitat complexity, few rocks and few other preferred consolidated substrata. We described the stages of cells of reproductive lineage, gonadal development and some reproductive traits which were compared with information in the available literature. Cells from the spermatogenic lineage were spermatogonia, spermatocytes, spermatids and spermatozoa, and cells from the oocytarian lineage were primary oocytes, previtelogenic oocytes, cortical vesicle oocytes and yolk globules or vitellogenic. Five stages were described for the males/females according to the distribution of oocytes and spermatogenic lineage cells: resting; initial maturation; advanced maturation; partially spent/spawned; totally spent/spawn. Females outnumbered males and reached larger size. Synchronic ovary development in two groups was found with diameter of mature oocytes ranging from 2 to 3.35 mm. Indication of early maturation, a longer reproductive period and the production of smaller eggs in small clutches seems to be features of the reservoir population not found in riverine systems. Such changes in tactics may indicate a shift to an opportunistic strategy, helping the population to withstand environmental constraints and to succeed in this oligotrophic and poorly structured reservoir.

  11. Spatiotemporal distributions of intestinal helminths in female lesser scaup Aythya affinis during spring migration from the upper Midwest, USA

    Science.gov (United States)

    England, J. C.; Levengood, J.M.; Osborn, J. M.; Yetter, A. P.; Kinsella, J.M.; Cole, Rebecca A.; Cory D. Suski,; Hagy, Heath M.

    2016-01-01

    We examined the associations between intestinal helminth infracommunity structure and infection parameters and the age, size, and year and region of collection of 130 female lesser scaup (Aythya affinis) during their 2014–2015 spring migrations through the upper Midwest, USA. We identified a total of 647,174 individual helminths from 40 taxa, including 20 trematodes, 14 cestodes, 4 nematodes and 2 acanthocephalans parasitizing lesser scaup within the study area. Lesser scaup were each infected with 2–23 helminth taxa. One digenean, Plenosoma minimum, is reported for the first time in lesser scaup and in the Midwest. Mean trematode abundance and total helminth abundance was significantly less in 2015 than 2014, and we suspect that colder weather late in 2015 impacted the intermediate host fauna and caused the observed differences. Brillouin's species diversity of helminths was greatest in the northernmost region of the study area, which coincides with the range of a non-indigenous snail that indirectly causes annual mortality events of lesser scaup. While host age and size were not determined to be influential factors of helminth infracommunity structure, non-parametric ordination and permutational analysis of co-variance revealed that year and region of collection explained differences in helminth infracommunities. Our results suggest that spatiotemporal variations play an important role in the structure of intestinal helminth infracommunities found in migrating lesser scaup hosts, and may therefore impact host ability to build endogenous reserves at certain stopover locations in the Midwest.

  12. The application of homemade Neosinocalamus affinis AC in electrokinetic removal technology on heavy metal removal from the MSWI fly ash

    Science.gov (United States)

    Liu, Kexiang; Huang, Tao; Huang, Xiao; Yu, Lin; Muhammad, Faheem; Jiao, Binquan; Li, Dongwei

    2016-12-01

    This present paper was focused on the manufacture of activated carbon (AC) and its application in the electrokinetic remediation (EKR) technology on removal of the heavy metals (HMs) from the municipal solid waste incineration fly ash. AC was produced from Neosinocalamus affinis (NF) by chemical activation with H3PO4 in N2 atmosphere, the effects of activation temperatures, soaking time and impregnation ratios on the adsorption capacity of AC on HMs were examined through equilibrium adsorption experiments. The AC produced under the condition of 450 °C of activation temperature, 10 h of soaking time and 1.5 of impregnation ration was applied in the EKR experiment. The addition of AC in the S3-region of the electrolyzer could effectively improve the removal efficiencies of HMs. The technical parameters of voltage gradient, processing time and proportion were further optimized in the coupled experiments, the maximum removal of Cu, Zn, Cd, and Pb was 84.93%, 69.61%, 79.57%, and 78.55% respectively obtained under the optimal operating conditions of 2 V/cm of voltage gradient, 8 d of processing time and 20% of proportion.

  13. Pleistocene climatic cycling drives intra-specific diversification in the intermediate horseshoe bat (Rhinolophus affinis) in Southern China.

    Science.gov (United States)

    Mao, Xiu Guang; Zhu, Guang Jian; Zhang, Shuyi; Rossiter, Stephen J

    2010-07-01

    The repeated formation and loss of land-bridges during the Pleistocene have had lasting impacts on population genetic structure. In the tropics, where island populations persisted through multiple glacial cycles, alternating periods of isolation and contact are expected to have driven population and taxonomic divergence. Here, we combine mitochondrial and nuclear sequence data with microsatellites to dissect the impact of Pleistocene climate change on intra-specific diversification in the horseshoe bat Rhinolophus affinis. This taxon shows considerable morphological and acoustic variation: two parapatric subspecies (himalayanus and macrurus) occur on mainland China and a third (hainanus) on Hainan Island. Our phylogeographic reconstruction and coalescent analyses suggest the island subspecies formed from an ancestral population of himalayanus via two colonization events c. 800,000 years before present. R. a. hainanus then recolonized the mainland, forming macrurus and thus a secondary contact zone with himalayanus. Finally, macrurus recolonized Hainan following the LGM. We found that all three biological events corresponded to known periods of land-bridge formation. Evidence of introgression was detected between macrurus and both its sister taxa, with geographical proximity rather than length of separation appearing to be the biggest determinant of subsequent genetic exchange. Our study highlights the important role of climate-mediated sea level changes have had in shaping current processes and patterns of population structure and taxonomic diversification.

  14. Enhancement of neutral lipid productivity in the microalga Isochrysis affinis Galbana (T-Iso) by a mutation-selection procedure.

    Science.gov (United States)

    Bougaran, Gaël; Rouxel, Catherine; Dubois, Nolwenn; Kaas, Raymond; Grouas, Sophie; Lukomska, Ewa; Le Coz, Jean-René; Cadoret, Jean-Paul

    2012-11-01

    Microalgae offer a high potential for energetic lipid storage as well as high growth rates. They are therefore considered promising candidates for biofuel production, with the selection of high lipid-producing strains a major objective in projects on the development of this technology. We developed a mutation-selection method aimed at increasing microalgae neutral lipid productivity. A two step method, based on UVc irradiation followed by flow cytometry selection, was applied to a set of strains that had an initial high lipid content and improvement was assessed by means of Nile-red fluorescence measurements. The method was first tested on Isochrysis affinis galbana (T-Iso). Following a first round of mutation-selection, the total fatty acid content had not increased significantly, being 262 ± 21 mgTFA (gC)-1 for the wild type (WT) and 269 ± 49 mgTFA (gC)-1 for the selected population (S1M1). Conversely, fatty acid distribution among the lipid classes was affected by the process, resulting in a 20% increase for the fatty acids in the neutral lipids and a 40% decrease in the phospholipids. After a second mutation-selection step (S2M2), the total fatty acid content reached 409 ± 64 mgTFA (gC)-1 with a fatty acid distribution similar to the S1M1 population. Growth rate remained unaffected by the process, resulting in a 80% increase for neutral lipid productivity.

  15. Factors affecting population fluctuations of the glacial relict amphipod Monoporeia affinis (Lindström) in Sweden's largest lakes.

    Science.gov (United States)

    Goedkoop, W; Johnson, R K

    2001-12-01

    Factors affecting long-term (1982-2000) population densities of the glacial relict amphipod Monoporeia affinis were studied in Sweden's three largest lakes. Monoporeia showed large population fluctuations in all three lakes, with conspicuous peaks in density occurring in Lakes Vänern and Mälaren. In Lake Vänern, amphipod densities showed highly significant relationships with spring maximum diatom biovolume at a 1-yr lag. The lack of relationship between diatom biovolumes and Monoporeia densities in L. Vättern is likely due to the larger depth and the lower nutrient content of this lake. In eutrophic L. Mälaren, summer hypoxia (< 4 mg O2 L-1) is likely an important regulating factor. Hypolimnetic temperature showed a clear periodicity with relatively warm deep water occurring between 1989 and 1994. Hypolimnetic temperatures in Vänern and Vättern were correlated with total solar irradiance. However, neither hypolimnetic water temperature nor diatom biovolumes correlated with the North Atlantic Oscillation winter index. We speculate that variations in temperature and near-bottom oxygen concentrations negatively affect population densities by acting on recruitment success (reproduction) and juvenile (young-of-the-year) survival.

  16. Accumulation of polyunsaturated aldehydes in the gonads of the copepod Acartia tonsa revealed by tailored fluorescent probes.

    Directory of Open Access Journals (Sweden)

    Stefanie Wolfram

    Full Text Available Polyunsaturated aldehydes (PUAs are released by several diatom species during predation. Besides other attributed activities, these oxylipins can interfere with the reproduction of copepods, important predators of diatoms. While intensive research has been carried out to document the effects of PUAs on copepod reproduction, little is known about the underlying mechanistic aspects of PUA action. Especially PUA uptake and accumulation in copepods has not been addressed to date. To investigate how PUAs are taken up and interfere with the reproduction in copepods we developed a fluorescent probe containing the α,β,γ,δ-unsaturated aldehyde structure element that is essential for the activity of PUAs as well as a set of control probes. We developed incubation and monitoring procedures for adult females of the calanoid copepod Acartia tonsa and show that the PUA derived fluorescent molecular probe selectively accumulates in the gonads of this copepod. In contrast, a saturated aldehyde derived probe of an inactive parent molecule was enriched in the lipid sac. This leads to a model for PUAs' teratogenic mode of action involving accumulation and covalent interaction with nucleophilic moieties in the copepod reproductive tissue. The teratogenic effect of PUAs can therefore be explained by a selective targeting of the molecules into the reproductive tissue of the herbivores, while more lipophilic but otherwise strongly related structures end up in lipid bodies.

  17. Prevalent ciliate symbiosis on copepods: high genetic diversity and wide distribution detected using small subunit ribosomal RNA gene.

    Science.gov (United States)

    Guo, Zhiling; Liu, Sheng; Hu, Simin; Li, Tao; Huang, Yousong; Liu, Guangxing; Zhang, Huan; Lin, Senjie

    2012-01-01

    Toward understanding the genetic diversity and distribution of copepod-associated symbiotic ciliates and the evolutionary relationships with their hosts in the marine environment, we developed a small subunit ribosomal RNA gene (18S rDNA)-based molecular method and investigated the genetic diversity and genotype distribution of the symbiotic ciliates on copepods. Of the 10 copepod species representing six families collected from six locations of Pacific and Atlantic Oceans, 9 were found to harbor ciliate symbionts. Phylogenetic analysis of the 391 ciliate 18S rDNA sequences obtained revealed seven groups (ribogroups), six (containing 99% of all the sequences) belonging to subclass Apostomatida, the other clustered with peritrich ciliate Vorticella gracilis. Among the Apostomatida groups, Group III were essentially identical to Vampyrophrya pelagica, and the other five groups represented the undocumented ciliates that were close to Vampyrophrya/Gymnodinioides/Hyalophysa. Group VI ciliates were found in all copepod species but one (Calanus sinicus), and were most abundant among all ciliate sequences obtained, indicating that they are the dominant symbiotic ciliates universally associated with copepods. In contrast, some ciliate sequences were found only in some of the copepods examined, suggesting the host selectivity and geographic differentiation of ciliates, which requires further verification by more extensive sampling. Our results reveal the wide occurrence and high genetic diversity of symbiotic ciliates on marine copepods and highlight the need to systematically investigate the host- and geography-based genetic differentiation and ecological roles of these ciliates globally.

  18. Prevalent ciliate symbiosis on copepods: high genetic diversity and wide distribution detected using small subunit ribosomal RNA gene.

    Directory of Open Access Journals (Sweden)

    Zhiling Guo

    Full Text Available Toward understanding the genetic diversity and distribution of copepod-associated symbiotic ciliates and the evolutionary relationships with their hosts in the marine environment, we developed a small subunit ribosomal RNA gene (18S rDNA-based molecular method and investigated the genetic diversity and genotype distribution of the symbiotic ciliates on copepods. Of the 10 copepod species representing six families collected from six locations of Pacific and Atlantic Oceans, 9 were found to harbor ciliate symbionts. Phylogenetic analysis of the 391 ciliate 18S rDNA sequences obtained revealed seven groups (ribogroups, six (containing 99% of all the sequences belonging to subclass Apostomatida, the other clustered with peritrich ciliate Vorticella gracilis. Among the Apostomatida groups, Group III were essentially identical to Vampyrophrya pelagica, and the other five groups represented the undocumented ciliates that were close to Vampyrophrya/Gymnodinioides/Hyalophysa. Group VI ciliates were found in all copepod species but one (Calanus sinicus, and were most abundant among all ciliate sequences obtained, indicating that they are the dominant symbiotic ciliates universally associated with copepods. In contrast, some ciliate sequences were found only in some of the copepods examined, suggesting the host selectivity and geographic differentiation of ciliates, which requires further verification by more extensive sampling. Our results reveal the wide occurrence and high genetic diversity of symbiotic ciliates on marine copepods and highlight the need to systematically investigate the host- and geography-based genetic differentiation and ecological roles of these ciliates globally.

  19. How much crude oil can zooplankton ingest? Estimating the quantity of dispersed crude oil defecated by planktonic copepods.

    Science.gov (United States)

    Almeda, Rodrigo; Connelly, Tara L; Buskey, Edward J

    2016-01-01

    We investigated and quantified defecation rates of crude oil by 3 species of marine planktonic copepods (Temora turbinata, Acartia tonsa, and Parvocalanus crassirostris) and a natural copepod assemblage after exposure to mechanically or chemically dispersed crude oil. Between 88 and 100% of the analyzed fecal pellets from three species of copepods and a natural copepod assemblage exposed for 48 h to physically or chemically dispersed light crude oil contained crude oil droplets. Crude oil droplets inside fecal pellets were smaller (median diameter: 2.4-3.5 μm) than droplets in the physically and chemically dispersed oil emulsions (median diameter: 6.6 and 8.0 μm, respectively). This suggests that copepods can reject large crude oil droplets or that crude oil droplets are broken into smaller oil droplets before or during ingestion. Depending on the species and experimental treatments, crude oil defecation rates ranged from 5.3 to 245 ng-oil copepod(-1) d(-1), which represent a mean weight-specific defecation rate of 0.026 μg-oil μg-Ccopepod(1) d(-1). Considering a dispersed crude oil concentration commonly found in the water column after oil spills (1 μl L(-1)) and copepod abundances in high productive coastal areas, copepods may defecate ∼ 1.3-2.6 mg-oil m(-3) d(-1), which would represent ∼ 0.15%-0.30% of the total dispersed oil per day. Our results indicate that ingestion and subsequent defecation of crude oil by planktonic copepods has a small influence on the overall mass of oil spills in the short term, but may be quantitatively important in the flux of oil from surface water to sediments and in the transfer of low-solubility, toxic petroleum hydrocarbons into food webs after crude oil spills in the sea.

  20. The use of chlorine dioxide for the inactivation of copepod zooplankton in drinking water treatment.

    Science.gov (United States)

    Lin, Tao; Chen, Wei; Cai, Bo

    2014-01-01

    The presence of zooplankton in drinking water treatment system may cause a negative effect on the aesthetic value of drinking water and may also increase the threat to human health due to they being the carriers of bacteria. Very little research has been done on the effects of copepod inactivation and the mechanisms involved in this process. In a series of bench-scale experiments we used a response surface method to assess the sensitivity of copepod to inactivation when chlorine dioxide (ClO₂) was used as a disinfectant. We also assessed the effects of the ClO₂dosage, exposure time, organic matter concentration and temperature. Results indicated that the inactivation rate improved with increasing dosage, exposure time and temperature, whereas it decreased with increasing organic matter concentration. Copepod inactivation was more sensitive to the ClO₂dose than that to the exposure time, while being maintained at the same Ct-value conditions. The activation energy at different temperatures revealed that the inactivation of copepods with ClO₂was temperature-dependent. The presence of organic matter resulted in a lower available dose as well as a shorter available exposure time, which resulted in a decrease in inactivation efficiency.

  1. Resting egg production induced by food limitation in the calanoid copepod Acartia tonsa

    DEFF Research Database (Denmark)

    Drillet, Guillaume; Hansen, Benni W.; Kiørboe, Thomas

    2011-01-01

    Three populations of the copepod Acartia tonsa, two from the Baltic Sea and one from the U.S. East Coast, were compared for resting egg production at conditions of saturating and limiting food availability. All three populations produced eggs that hatched within 72 h when incubated at 17°C (subit...

  2. Extreme temperature and oil contamination shape the relative abundance of copepod species in the Arctic

    DEFF Research Database (Denmark)

    Dinh, Khuong Van; Nielsen, Torkel Gissel

    is of north Atlantic origin. Pyrene is one of the most toxic components of crude oil to marine copepods. The temperatures of 2, 6 and 10°C represent the mean sea water temperature, the 4°C increase in mean temperature by 2100 as predicted by IPCC scenario RCP8.5 (2013) and the extreme sea water temperature...

  3. Reading the copepod personal ads : increasing encounter probability with hydromechanical signals

    NARCIS (Netherlands)

    van Duren, LA; Stamhuis, EJ; Videler, JJ

    1998-01-01

    Females of the calanoid copepod Temora longicornis react to chemical exudates of male conspecifics with little hops, quite distinct from their normal smooth uniform swimming motion. These hops possibly serve to create a hydrodynamical signal in the surrounding water, to increase encounter probabilit

  4. First records of parasitic copepods (Crustacea, Siphonostomatoida) from marine fishes in Korea.

    Science.gov (United States)

    Venmathi Maran, B A; Soh, H Y; Hwang, U W; Chang, C Y; Myoung, J G

    2015-06-01

    The knowledge of the biodiversity of parasitic copepods in South Korea is increasing. Interestingly we report here, some parasitic copepods considered as the first record of findings from Korea. Nine species of parasitic copepods (Siphonostomatoida) including six genera of three different families [Caligidae (7), Lernaeopodidae (1), Lernanthropidae (1)] were recovered from eight species of wild fishes in Korea: 1) Caligus hoplognathi Yamaguti & Yamasu, 1959 (♀, ♂) from the body surface of barred knifejaw Oplegnathus fasciatus (Temminck & Schlegel); 2) Caligus lagocephali Pillai, 1961 (♀) from the gills of panther puffer Takifugu pardalis (Temminck & Schlegel); 3) Euryphorus brachypterus (Gerstaecker, 1853) (♀, ♂) from the opercular cavity of Atlantic bluefin tuna Thunnus thynnus (Linnaeus); 4) Euryphorus nordmanni Milne Edwards, 1840 (♀, ♂) from the opercular cavity of common dolphin fish Coryphaena hippurus Linnaeus; 5) Gloiopotes huttoni (Thomson) (♀, ♂) from the body surface of black marlin Istiompax indica (Cuvier); 6) Lepeophtheirus hapalogenyos Yamaguti & Yamasu, 1959 (♀) from the gill filaments of O. fasciatus; 7) Lepeophtheirus sekii Yamaguti, 1936 (♀, ♂) from the body surface of red seabream Pagrus major (Temminck & Schlegel); 8) Brachiella thynni Cuvier, 1830 (♀) from the body surface of longfin tuna or albacore Thunnus alalunga (Bonnaterre); 9) Lernanthropinus sphyraenae (Yamaguti & Yamasu, 1959) (♀) from the gill filaments of moon fish Mene maculata (Bloch & Schneider). Since the female was already reported in Korea, it is a new record for the male of C. hoplognathi. A checklist for the parasitic copepods of the family Caligidae, Lernaeopodidae and Lernanthropidae of Korea is provided.

  5. Salinity-induced survival strategy of Vibrio cholerae associated with copepods in Cochin backwaters

    Digital Repository Service at National Institute of Oceanography (India)

    Thomas, K.U.; Joseph, N.; Raveendran, O.; Nair, S.

    ., 1999. Economic and social issues of biodiversity loss in Cochin backwaters. The Kerala Research Programme on Local Level Devel- opment, Report. Bastos, A.D., Silveira, M.S.C., Laureˆnia, M.B.A., Ernesto, H., 1996. Influence of the copepod Mesocyclops...

  6. Effects of copepod size on fish growth: A model based on data for North Sea sandeel

    DEFF Research Database (Denmark)

    Deurs, Mikael van; Jørgensen, C.; Fiksen, Ø.

    2015-01-01

    mechanistic models from relevant data: (1) a model of the bioenergetics and stomach filling/evacuation dynamics, and (2) a Holling type II functional response model that encompasses visual range from basic principles. The model predicts that going from a situation where large Calanus copepods (2 mm) dominate...

  7. Escape from viscosity : the kinematics and hydrodynamics of copepod foraging and escape swimming

    NARCIS (Netherlands)

    van Duren, LA; Videler, JJ

    2003-01-01

    Feeding and escape swimming in adult females of the calanoid copepod. Temora lopgicornis Muller were investigated and compared. Swimming velocities were calculated using a 3-D filming setup., Foraging velocities ranged between 2 and 6 min s(-1), while maximum velocities of up to 80 mm s(-1) were rea

  8. Role of dispersants of oil on copepods in high arctic areas

    DEFF Research Database (Denmark)

    Gustavson, Kim; Nørregaard, Rasmus Dyrmose; Møller, Eva Friis

    2013-01-01

    The purpose of the project is to increase the knowledge on the effects of using dispersants on oil spills in high arctic areas: more precisely, to investigate accumulation in and effects on high arctic copepods. Such knowledge is crucial for performing a robust net environmental benefit analysis...

  9. Trophic interactions and productivity of copepods as live feed from tropical Taiwanese outdoor aquaculture ponds

    DEFF Research Database (Denmark)

    Blanda, Elisa; Drillet, Guillaume; Huang, Cheng-Chien

    2015-01-01

    of phytoplankton available in the ponds was high (value of chlorophyll a in average 97.7 ± 10.9 μg L− 1) and dominated by diatoms, flagellates and pico-algae. The estimated abundance and biomass of adult copepods and copepodites of P. annandalei was on average 93 ± 40 individuals L− 1 and 214 ± 98 μg C L− 1...... to enable a correct description of the copepods ecology and a preliminary evaluation of the status of the pond management; and (III) provide advices for improved management leading towards a higher and more stable output of P. annandalei. Copepods were experiencing prey ad libitum since the quantity......, respectively. P. annandalei's specific growth rate in the ponds, thus the secondary productivity, was 0.89 ± 0.1 d− 1 (average ± S.D.). The average harvest (21 kg of copepods wet weight per pond every second to fifth day), was a relatively low quantity to satisfy the demand of the fish farmers, especially...

  10. Ostrincola breviseti n. sp., a copepod parasite of an oyster from Penang, Malaysia

    NARCIS (Netherlands)

    Ho, Ju-shey; Kim, Il-Hoi

    1990-01-01

    A new species of poecilostomatoid copepod, Ostrincola breviseti, is described from the mantle cavity of the oyster, Saccostrea cucullata (Born), collected at Penang, Malaysia. The new species is distinguished by the short terminal setae on leg 5. The species of Ostrincola are discussed in terms of t

  11. A parameter for detecting estrogenic exposure in the copepod Acartia tonsa

    DEFF Research Database (Denmark)

    Andersen, Henrik Rasmus; Halling-Sørensen, Bent; Kusk, Kresten Ole

    1999-01-01

    in a steeper maturation profile. The proposed endpoint was identified by exposing copepods to the natural estrogen 17 beta-estradiol and the antropogenic estrogen bisphenol A. Both compounds produced significant effects at 23 and 20 mu g/L respectively. Since bisphenol A is traditionally believed to be less...

  12. Dissonus pastinum n. sp. (Siphonostomatoida: Dissonidae), a copepod parasitic on a horn shark from Japan

    NARCIS (Netherlands)

    Deets, Gregory B.; Dojiri, Masahiro

    1990-01-01

    A new species of siphonostomatoid copepod, Dissonus pastinum, is described from the horn shark, Heterodontus japonicus (Dumeril), from Awa, Japan. The new species differs from all congeners except D. ruvetti Nunes-Ruivo & Fourmanoir, 1956 and D. nudiventris Kabata, 1965 by the presence of the

  13. Seasonal copepod lipid pump promotes carbon sequestration in the deep North Atlantic

    DEFF Research Database (Denmark)

    Jonasdottir, Sigrun; Visser, Andre; Richardson, Katherine

    2015-01-01

    Significance Every autumn across the North Atlantic, large numbers of zooplankton copepods migrate from the surface waters into the ocean's interior to hibernate at depths of 600–1,400 m. Through this migration, they actively transport lipid carbon to below the permanent thermocline, where it is ...

  14. Feeding season duration and the relative success of capital and income spawning copepods

    DEFF Research Database (Denmark)

    Sainmont, Julie; Varpe, Øystein; Andersen, Ken Haste;

    to the spring bloom, using only its reserves accumulated the previous year (capital breeder). The success of these two strategies is related to the length of the spring bloom, the only source of nutrients for these copepods. We use an individual based model to approach the question of income versus capital...

  15. Non-consumptive effects of predator presence on copepod reproduction: insights from a mesocosm experiment

    DEFF Research Database (Denmark)

    Heuschele, Jan; Ceballos, Sara; Borg, Marc Andersen;

    2014-01-01

    Reproduction in planktonic animals depends on numerous biotic and abiotic factors. One of them is predation pressure, which can have both direct consumptive effects on population density and sex ratio, and non-consumptive effects, for example on mating and migration behaviour. In copepods, predat...

  16. The parasitic copepod Lernaeocera branchialis negatively affects cardiorespiratory function in Gadus morhua

    DEFF Research Database (Denmark)

    Behrens, Jane W.; Seth, H.; Axelsson, M.

    2014-01-01

    The parasitic copepod Lernaeocera branchialis had a negative effect on cardiorespiratory function in Atlantic cod Gadus morhua such that it caused pronounced cardiac dysfunction with irregular rhythm and reduced stroke amplitude compared with uninfected fish. In addition, parasite infection...... depressed the postprandial cardiac output and oxygen consumption...

  17. Dissonus pastinum n. sp. (Siphonostomatoida: Dissonidae), a copepod parasitic on a horn shark from Japan

    NARCIS (Netherlands)

    Deets, Gregory B.; Dojiri, Masahiro

    1990-01-01

    A new species of siphonostomatoid copepod, Dissonus pastinum, is described from the horn shark, Heterodontus japonicus (Dumeril), from Awa, Japan. The new species differs from all congeners except D. ruvetti Nunes-Ruivo & Fourmanoir, 1956 and D. nudiventris Kabata, 1965 by the presence of the sterna

  18. Distribution of calanoid copepods in the Arabian sea and Bay of Bengal

    Digital Repository Service at National Institute of Oceanography (India)

    Stephen, R.

    . Numerical abundance was high in the shelf stations. Secondary production considered in terms of copepod density showed the ratio 2:1 between the Arabian Sea and Bay of Bengal. The water column from the top layer of thermocline to surface was dominated...

  19. Synopsis of lichomolgid copepods (Poecilostomatoida) associated with soft corals (Alcyonacea) in the tropical Indo-Pacific

    NARCIS (Netherlands)

    Humes, A.G.

    1990-01-01

    A synopsis of the 97 species of lichomolgid copepods known to be associated with tropical IndoPacific shallow-water alcyonaceans is given (Madagascar, New Caledonia, Moluccas, Philippines, and Enewetak Atoll). One new genus and 29 new species are included, distributed among the lichomolgid genera Ac

  20. Genetic responses of the marine copepod Acartia tonsa (Dana) to heat shock and epibiont infestation

    DEFF Research Database (Denmark)

    Petkeviciute, Egle; Kania, Per Walter; Skovgaard, Alf

    2015-01-01

    Expression of stress-related genes was investigated in the marine copepod Acartia tonsa in relation to heat shock at two different salinities (10 and 32‰), and it was furthermore investigated whether experimentally induced epibiont infestation led to elevated expression of stress-related genes...

  1. Spatio-temporal distribution and production of calanoid copepods in the central Baltic Sea

    DEFF Research Database (Denmark)

    Hansen, F.C.; Möllmann, Christian; Schutz, U.

    2006-01-01

    The aim of our study was the exploration of species-specific distribution and production patterns of dominant copepods in the Central Baltic Sea (Bornholm Basin). Spatio-temporal distribution, egg and secondary production were studied by means of net-sampling and egg production experiments from A...

  2. New hypogean cyclopoid copepods (Crustacea) from the Yucatán Peninsula, Mexico

    NARCIS (Netherlands)

    Fiers, Frank; Reid, Janet W.; Iliffe, Thomas M.; Suárez-Morales, Eduardo

    1996-01-01

    Four previously unknown hypogean species of cyclopoid copepods were collected in cenotes and wells of the Yucatán Peninsula, Mexico. Diacyclops chakan sp. n. and D. puuc sp. n. differ from their congeners in combining 3-segmented swimming legs, 11-segmented antennules, and legs 1-4 endopodite

  3. Increased tolerance to oil exposure by the cosmopolitan marine copepod Acartia tonsa.

    Science.gov (United States)

    Krause, Kamille Elvstrøm; Dinh, Khuong V; Nielsen, Torkel Gissel

    2017-12-31

    Oil contamination is an environmental hazard to marine ecosystems, but marine organism tolerance to oil after many generations of exposure remains poorly known. We studied the effects of transgenerational oil exposure on fitness-related traits in a cosmopolitan neritic copepod, Acartia tonsa. Copepods were exposed to an oil compound, the PAH pyrene, at concentrations of 1, 10, 100 and 100+(the saturated pyrene concentration in seawater)nM over two generations and measured survival, sex ratio, size at maturity, grazing rate and reproductive success. Exposure to the pyrene concentration of 100+nM resulted in 100% mortality before adulthood in the first generation. At the pyrene concentration of 100nM, pyrene reduced grazing rate, increased mortality, reduced the size of females and caused lower egg production and hatching success. Importantly, we found strong evidence for increased tolerance to pyrene exposure in the second generation: the reduction in size at maturity of females was less pronounced in the second generation and survival, egg production and hatching success were recovered to control levels in the second generation. The increased tolerance of copepods to oil contamination may dampen the direct ecological consequences of a coastal oil spill, but it raises the concern whether a larger fraction of oil components accumulated in survived copepods, may be transferred up the food web. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. SWIMMING BEHAVIOR OF DEVELOPMENTAL STAGES OF THE CALANOID COPEPOD TEMORA-LONGICORNIS AT DIFFERENT FOOD CONCENTRATIONS

    NARCIS (Netherlands)

    VANDUREN, LA; VIDELER, JJ

    1995-01-01

    The swimming behaviour of developmental stages of the marine calanoid copepod Temora longicornis was studied using 2-dimensional observations under a microscope and a 3-dimensional filming technique to analyze swimming mode, swimming speed and swimming trajectories under different food concentration

  5. Genetic responses of the marine copepod Acartia tonsa (Dana) to heat shock and epibiont infestation

    DEFF Research Database (Denmark)

    Petkeviciute, Egle; Kania, Per Walter; Skovgaard, Alf

    2015-01-01

    Expression of stress-related genes was investigated in the marine copepod Acartia tonsa in relation to heat shock at two different salinities (10 and 32‰), and it was furthermore investigated whether experimentally induced epibiont infestation led to elevated expression of stress-related genes. E...

  6. Blind dating - mate finding in planktonic copepods. III. Hydromechanical communication in Acartia tonsa

    DEFF Research Database (Denmark)

    Bagoien, E.; Kiørboe, Thomas

    2005-01-01

    Mate-finding behaviour in the marine copepod Acartia tonsa was examined by video analysis. A. tonsa appears to depend on hydromechanical signals in the location of mates, detected at distances of up to 5 or 7 mm. Series of up to 7 or 8 synchronised hops in closely situated individuals, interpreted...

  7. New hypogean cyclopoid copepods (Crustacea) from the Yucatán Peninsula, Mexico

    NARCIS (Netherlands)

    Fiers, Frank; Reid, Janet W.; Iliffe, Thomas M.; Suárez-Morales, Eduardo

    1996-01-01

    Four previously unknown hypogean species of cyclopoid copepods were collected in cenotes and wells of the Yucatán Peninsula, Mexico. Diacyclops chakan sp. n. and D. puuc sp. n. differ from their congeners in combining 3-segmented swimming legs, 11-segmented antennules, and legs 1-4 endopodite segmen

  8. Dissonus pastinum n. sp. (Siphonostomatoida: Dissonidae), a copepod parasitic on a horn shark from Japan

    NARCIS (Netherlands)

    Deets, Gregory B.; Dojiri, Masahiro

    1990-01-01

    A new species of siphonostomatoid copepod, Dissonus pastinum, is described from the horn shark, Heterodontus japonicus (Dumeril), from Awa, Japan. The new species differs from all congeners except D. ruvetti Nunes-Ruivo & Fourmanoir, 1956 and D. nudiventris Kabata, 1965 by the presence of the sterna

  9. Blind dating - mate finding in planktonic copepods. III. Hydromechanical communication in Acartia tonsa

    DEFF Research Database (Denmark)

    Bagoien, E.; Kiørboe, Thomas

    2005-01-01

    Mate-finding behaviour in the marine copepod Acartia tonsa was examined by video analysis. A. tonsa appears to depend on hydromechanical signals in the location of mates, detected at distances of up to 5 or 7 mm. Series of up to 7 or 8 synchronised hops in closely situated individuals, interpreted...

  10. Influence of LAS on marine calanoid copepod population dynamics and potential reproduction

    DEFF Research Database (Denmark)

    Christoffersen, Kirsten; Hansen, Benni Winding; Johansson, Liselotte Sander

    2003-01-01

    The toxicity of linear alkyl benzene sulfonate (LAS) to marine invertebrates is well documented under laboratory conditions using single-species tests. It is less known how LAS affects natural populations of aquatic organisms. We hypothesised that LAS was more toxic to the calanoid copepod Acarti...

  11. Biochemical composition of the promising live feed tropical calanoid copepod Pseudodiaptomus annandalei (Sewell 1919) cultured in Taiwanese outdoor aquaculture ponds

    DEFF Research Database (Denmark)

    Rayner, Thomas Allan; Jørgensen, Niels O. G.; Blanda, Elisa

    2015-01-01

    The use of copepods as live feed has shown good potential, and in Taiwan copepods are harvested specifically as live feed for fin-fish production. The calanoid copepod Pseudodiaptomus annandalei is a species found typically in Taiwanese aquaculture and in the rest of the Indo-Pacific region...... combined relative abundance of 21.8% of total fatty acid content. The fatty acid C20:4 n − 6 (ARA) was present in adult females and late stage nauplii. Overall, P. annandalei demonstrated good trophic transfer capabilities of HUFAs. Discrepancies between adult female and seston fatty acid profiles indicate...

  12. Proteocephalidean larvae (Cestoda in naturally infected cyclopid copepods of the upper Paraná River floodplain, Brazil

    Directory of Open Access Journals (Sweden)

    Dina Lúcia Morais Falavigna

    2003-01-01

    Full Text Available The occurrence, prevalence and infection intensity of proteocephalidean larvae in naturally infected intermediate hosts of the Upper Paraná River floodplain are reported. A total of 5,206 zooplanktonic and benthic organisms were analyzed, namely cyclopid (2,621 and calanoid (1,479 copepods, cladocerans (704, rotifers (307, chironomid larvae (41 and ostracods (54. Eight cyclopid copepods - two copepodids, one male and five females - comprising 0.3% of the cyclopid copepods examined, were naturally infected. The male infected belonged to a species of Paracyclops, and the females to Paracyclops sp., Thermocyclops minutus and Mesocyclops longisetus.

  13. Effect of ocean acidification on the nutritional quality of phytoplankton for copepod reproduction

    Science.gov (United States)

    Meyers, M.; Cochlan, W. P.; Kimmerer, W.; Carpenter, E. J.

    2016-02-01

    Phytoplankton are the oceans' primary producers of essential polyunsaturated fatty acids (PUFA), which provide marine organisms with nutrients needed for health and reproduction. It is hypothesized that future ocean acidification (OA) conditions could change the availability of phytoplankton PUFAs for ecologically significant predators such as copepods, affecting their reproductive success. Three species of phytoplankton (Rhodomonas salina, Skeletonema marinoi, Prorocentrum micans) were cultured under present-day (400ppm CO2, pH 8.1) and predicted future (1000ppm CO2, pH 7.8) oceanic conditions. For four days, female Acartia tonsa copepods were fed a phytoplankton mixture from either the present-day or predicted-future treatment. To assess changes in phytoplankton PUFA content, fatty acid profiles were analyzed via capillary gas chromatography. Copepod egg production (EP), hatching success (HS), and egg viability (EV) were determined to assess copepod reproductive success. Fatty acid analysis shows essential PUFAs comprise a smaller percentage of total fatty acids in phytoplankton cultured under high pCO2 (Rho 21.5%; Ske 14.1%; Pro 14.4%) compared to those cultured under present-day pCO2 (Rho 28.8%, Ske 32.7%, Pro 39.3%). Copepod reproduction data demonstrate that females fed phytoplankton cultured under high pCO2 have significantly lower EP (μ=14.3 eggs female-1), HS (μ=35.8%), and EV (μ=12.5%) compared to reproductive success of females fed phytoplankton cultured under present-day CO2 (EP μ=27.0 eggs female-1; HS μ=91.5%; EV μ=96.6%). This study demonstrates that OA can change the nutritional quality of primary producers, which can affect the reproductive success of fundamental secondary consumers.

  14. Seasonal cycles of zooplankton from San Francisco Bay

    Science.gov (United States)

    Ambler, Julie W.; Cloern, James E.; Hutchinson, Anne

    1985-01-01

    The two estuarine systems composing San Francisco Bay have distinct zooplankton communities and seasonal population dynamics. In the South Bay, a shallow lagoon-type estuary, the copepods Acartia spp. and Oithona davisae dominate. As in estuaries along the northeast coast of the U.S., there is a seasonal succession involving the replacement of a cold-season Acartia species (A. clausi s.l.) by a warm-season species (A. californiensis), presumably resulting from the differential production and hatching of dormant eggs. Oithona davisae is most abundant during the fall. Copepods of northern San Francisco Bay, a partially-mixed estuary of the Sacramento-San Joaquin Rivers, organize into discrete populations according to salinity distribution: Sinocalanus doerrii (a recently introduced species) at the riverine boundary, Eurytemora affinis in the oligohaline mixing zone, Acartia spp. in polyhaline waters (18–30\\%), and neritic species (e.g., Paracalanus parvus) at the seaward boundary. Sinocalanus doerrii and E. affinis are present year-round. Acartia clausi s.l.is present almost year-round in the northern reach, and A. californiensis occurs only briefly there in summer-fall. The difference in succession of Acartia species between the two regions of San Francisco Bay may reflect differences in the seasonal temperature cycle (the South Bay warms earlier), and the perennial transport of A. clausi s.l. into the northern reach from the seaward boundary by nontidal advection.

  15. Evaluation of halofenozide against prey mosquito larvae Culex pipiens and the predator fish Gambusia affinis: impact on growth and enzymatic activities.

    Science.gov (United States)

    Soltani, N; Chouahda, S; Smagghe, G

    2008-01-01

    Culex pipiens (Diptera: Culicidae) is the most widely distributed mosquito species in Algeria and many other countries in the world. Mosquitoes are generally controlled by conventional insecticides but these may pose strong secondary effects on the environment. In this context, the insect growth regulators (IGRs) have shown promise in controlling pest insects. Halofenozide (23% EC) is a novel IGRs belonging to the class of non-steroidal ecdysone agonists, and it was found toxic for larvae of C. pipiens. In addition biological methods constitute an alternative to chemical control. Several fish species have been tested against mosquitoes, and Gambusia affinis was found very efficient. In the present study we evaluated the impact of this new potent insecticide (halofenozide) on growth and metric indexes in the larvivorous fish G. affinis under laboratory conditions. In addition, the effects were evaluated on the enzymatic activities of acetyl cholinesterase (AChE) and glutathione S-transferase (GST). The insecticide was added in water at two concentrations (12.6 and 28.6 microg/L) corresponding to the LC50 and LC90 obtained against fourth instar larvae of C. pipiens, and adult females of G. affinis were exposed to halofenozide for 30 days. At different exposure times we measured the length and weight of fishes, the index of condition (K), the gonado-somatic ratio (GSR) and the hepato-somatic ratio (HSR). The results showed that halofenozide had no significant (p>0.05) effects on growth, metric indexes and AChE activities. However, treatment caused a significant induction (p<0.05) in GST activities at days 15 and 30 with the highest dose. Our results indicate that this ecdysteroid agonist presented only minor secondary effects on the non-target fish species, and so it has potential for controlling of mosquitoes in an integrated manner.

  16. 食蚊鱼的生物电场特征%THE BIOELECTRIC FIELD OF GAMBUSIA AFFINIS

    Institute of Scientific and Technical Information of China (English)

    张旭光; 宋佳坤; 张国胜; 范纯新; 郭弘艺; 王晓杰

    2011-01-01

    Sturgeon is an ancestor electrosensory fish which is able to sense the electric fields of prey animals and other sources. The character of bioelectric fields in environment is an important stimulus to investigate the electrosensory information processing in the brain. However, there were a few documents on bioelectric fields. In this study, the bioelectric fields of Gambusia affinis were measured in living fish, which was used as prey fish of Siberian Sturgeon in laboratory and the common small fish in southern China. They were measured and charactered in three experimental groups: single fish group, pair in same direction group and pair in opposite direction group. The bioelectric field of single fish showed typical features of dipole field, with relative potential up to (-24±2.4) uV on head and (21 ±1.6) uV on tail. There was (4.2±0.8) uV alternating current electric with 1-3 Hz on head which was corresponded with the respiratory rhythm of the fish. In other two experimental groups, the direct current electric fields were larger than the single fish group (P<0.05). However, the alternating current electric field of single fish group was significant bigger than pair in opposite direction group (3.8±0.7) uV but smaller than pairs in same direction group (4.5±0.8) uV (P<0.01). It suggested that the schooling fish could evade the predators by modulating the alternating current respiratory potential. It was maybe a kind of ancestral anti-predator strategy for fish to meet the passive electroreception, and further research would carry on electrophysiology.%文章采用活体记录的方法测量了食蚊鱼(Gambusia affinis)的生物电场.实验分单尾鱼、两尾鱼同向和两尾鱼反向三组测量,每组10个重复.结果表明:单尾鱼的生物电场表现为头负、尾正的偶极子直流电场,头部相对电势为(-24±2.4)μ v,尾部为(21±1 6)μ v,且头部附近产生1-3 Hz与呼吸频率对应的交流呼吸电场,大小为(4.2±0.8)μV.两尾

  17. Laboratory scale photobioreactor for high production of microalgae Rhodomonas salina used as food for intensive copepod cultures

    DEFF Research Database (Denmark)

    Thuy, Minh Vu Thi; Jepsen, Per Meyer; Hansen, Benni Winding

    Introduction Microalgae are essential feeds for many cultured molluscs, larvae of marine fishes, crustaceans as well as other important live feeds including rotifers, Artemia and copepods (Muller-Feuga, 2000). Microalgae are grown either in open culture systems (ponds) or closed systems...... (photobioreactor - PBR). There is an increasing interest in using closed PBRs for algae cultivation since this culture system provides a better control of cultivation conditions and enables higher algae productivity. Among the marine microalgae, the cryptophyte Rhodomonas salina is one of the optimal feed...... for copepods (Støttrup and Jensen, 1990; Zhang et al., 2013). Despite the benefit of using R. salina in cultivation of copepods, to our knowledge, there is no report on the production of this microalga at industrial scale to supply sufficient food for mass production of copepods. We intend to conduct the basic...

  18. First record of the Calanoid Copepod Pseudodiaptomus serricaudatus (Scott, T. 1894), (Copepoda: Calanoida: Pseudodiaptomidae) in the equatorial Indian ocean.

    Digital Repository Service at National Institute of Oceanography (India)

    Rebello, V.; Narvekar, J.; Gadi, P.; Venenkar, A.; Gauns, M.; PrasannaKumar, S.

    , Pondicherry University, Port Blair, Andaman 3Happy Home Apartment, Near Canara Bank, Fatorda, Margao, Goa-403602 Abstract Pseudodiaptomus serricaudatus (Scott, T. 1894), a planktonic copepod belonging to the family Pseudodiaptomidae, though has...

  19. Differences in the structure of copepod assemblages in four tropical estuaries: Importance of pollution and the estuary hydrodynamics.

    Science.gov (United States)

    Araujo, Adriana V; Dias, Cristina O; Bonecker, Sérgio L C

    2017-02-15

    We examined the relationship between pollution and structure of copepod assemblages in estuaries, using sampling standardization of salinity range to reduce the effects of "Estuarine Quality Paradox". Copepod assemblages were analyzed in four Southeast Brazilian estuaries with different water quality levels and different hydrodynamic characteristics. The pollution negatively impacted the descriptors of the assemblage structure. The distribution of structure of copepod assemblages also showed a main separation trend between the most polluted estuaries and those less polluted. Temperature was the main factor affecting the assemblage structuring in the four estuaries. This factor acted in synergism with the effects of pollution impact and physical characteristics of the estuaries on the structure of copepod assemblages, supporting the potential vulnerability of coastal environments due to nutrient enrichment associated with climate change. Our study demonstrated the importance of sampling standardization of the salinity range in estuaries for reliable analysis of pollution effects on biota. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Influence of algal diet on feeding and egg-production of the calanoid copepod Acartia tonsa Dana

    DEFF Research Database (Denmark)

    Støttrup, Josianne; Jensen, Johanne

    1990-01-01

    Threshold concentration, retention efficiency and egg-production in the calanoid copepod Acartia tonsa Dana were examined using the algal species Isochrysis galbana clone T-iso, Dunalietta tertiolecta Butcher, Rhodomonas baltica Karsten, Ditylum brightwellii Grunow and Thalassiosira weissflogii...

  1. Observations on feeding behaviour and survival rates in the estuarine calanoid copepods Acartia spinicauda and Heliodiaptomus cinctus (Crustacea: Copepoda: Calanoida)

    Digital Repository Service at National Institute of Oceanography (India)

    Srivastava, Y.; Fernandes, Brenda; Goswami, S.C.; Goswami, U.; Achuthankutty, C.T.

    Experiments were conducted on the calanoid copepods, Acartia spinicauda (Acartiidae) and Heliodiaptomus cinctus (Diaptomidae) in order to determine food preference and survival rates respectively. Adults of A. spinicauda were fed monocultures...

  2. Lipid reserves of Lesser Scaup (Aythya Affinis) migrating across a large landscape are consistent with the "Spring Condition" hypothesis

    Science.gov (United States)

    Anteau, M.J.; Afton, A.D.

    2009-01-01

    The "spring condition" hypothesis (SCH) states that nutrition during spring migration affects survival, reproductive success, and, ultimately, population size of migratory birds. The North American population of Lesser Scaup (Aythya affinis) has experienced a marked decline, apparently because of poor recruitment. An important prediction of the SCH is that female Lesser Scaup have low lipid reserves during spring migration. We previously reported that lipid reserves and body mass of females collected on migratory stopover areas in northwestern Minnesota in springs 2000-2001 were lower than those on the same areas in the 1980s and markedly lower than those collected at Pool 19 of the Mississippi River in 2000-2001, an important preceding stopover area. However, it was unclear whether these findings represented a site-specific result or a landscape-scale phenomenon. Accordingly, we examined lipid and body mass of 641 female Lesser Scaup migrating across seven eco-physiographic regions of Iowa, Minnesota, and North Dakota during springs 2003-2005. We found that lipids and body mass of females throughout the Upper Midwest were similar to or less than the low values documented in northwestern Minnesota in springs 2000-2001 and markedly lower than those of females at Pool 19 in springs 2000-2001. Accordingly, our results are consistent with a prediction of the SCH, because lipid and body mass of females are low throughout this large landscape, lower than at an important preceding stopover area, and lower than all historical values. Finally, our results suggest the potential for cross-seasonal influences of nutrition on recruitment and that a stronger management focus on spring migration habitats may be necessary for conservation and recovery of declining migratory birds, especially Lesser Scaup. ?? The American Ornithologists' Union, 2009.

  3. Maximum sustainable speeds and cost of swimming in juvenile kawakawa tuna (Euthynnus affinis) and chub mackerel (Scomber japonicus).

    Science.gov (United States)

    Sepulveda, C; Dickson, K A

    2000-10-01

    Tunas (Scombridae) have been assumed to be among the fastest and most efficient swimmers because they elevate the temperature of the slow-twitch, aerobic locomotor muscle above the ambient water temperature (endothermy) and because of their streamlined body shape and use of the thunniform locomotor mode. The purpose of this study was to test the hypothesis that juvenile tunas swim both faster and more efficiently than their ectothermic relatives. The maximum sustainable swimming speed (U(max), the maximum speed attained while using a steady, continuous gait powered by the aerobic myotomal muscle) and the net cost of transport (COT(net)) were compared at 24 degrees C in similar-sized (116-255 mm fork length) juvenile scombrids, an endothermic tuna, the kawakawa (Euthynnus affinis) and the ectothermic chub mackerel (Scomber japonicus). U(max) and COT(net) were measured by forcing individual fish to swim in a temperature-controlled, variable-speed swimming tunnel respirometer. There were no significant interspecific differences in the relationship between U(max) and body mass or fork length or in the relationship between COT(net) and body mass or fork length. Muscle temperatures were elevated by 1.0-2.3 degrees C and 0.1-0.6 degrees C above water temperature in the kawakawa and chub mackerel, respectively. The juvenile kawakawa had significantly higher standard metabolic rates than the chub mackerel, because the total rate of oxygen consumption at a given swimming speed was higher in the kawakawa when the effects of fish size were accounted for. Thus, juvenile kawakawa are not capable of higher sustainable swimming speeds and are not more efficient swimmers than juvenile chub mackerel.

  4. Relationships of cadmium, mercury, and selenium with nutrient reserves of female lesser scaup (Aythya affinis) during winter and spring migration

    Science.gov (United States)

    Anteau, M.J.; Afton, A.D.; Custer, Christine M.; Custer, T.W.

    2007-01-01

    Trace elements may have important effects on body condition of ducks during spring migration, because individuals are experiencing energetically costly events (e.g., migration, nutrient reserve accumulation, pair formation, feather molt, and ovarian follicle development). We examined relationships among hepatic cadmium, mercury, and selenium concentrations (??g/g dry wt) and nutrient reserves (lipid, protein, and mineral) of female lesser scaup (Aythya affinis) during winter and spring migration at four locations within the Mississippi Flyway (LA, IL, and MN, USA, and MB, Canada). Selenium concentrations (range, 3.73-52.29 (??g/g dry wt) were positively correlated with lipid reserves (F1,73 = 22.69, p lipid reserves (F1,73 = 6.92, p = 0.010, type III partial r2 = 0.09). The observed relationship between cadmium and lipid reserves may be cause for concern, because lipid reserves of females declined by 55 g (47%), on average, within the range of observed cadmium concentrations (0.23-7.24 ??g/g dry wt), despite the relatively low cadmium concentrations detected. Mean cadmium concentrations were higher in Minnesota (1.23 ??g/g dry wt) and Manitoba (1.11 ??g/g dry wt) than in Louisiana (0.80 ??g/g dry wt) and Illinois (0.69 ??g/g dry wt). However, mean cadmium concentrations predict lipid reserves of females to be only 11 g lower, on average, in Minnesota than in Illinois. Previous research documented that lipid reserves were 100 g lower in Minnesota than in Illinois; consequently, cadmium is unlikely to be the sole cause for decreases in lipid reserves of females during late-spring migration. ?? 2007 SETAC.

  5. Larval development of Cyrtograpsus affinis (Dana (Decapoda, Brachyura, Varunidae from Río de la Plata estuary, reared in the laboratory

    Directory of Open Access Journals (Sweden)

    Eduardo D. Spivak

    2000-03-01

    Full Text Available The complete larval development of the crab Cyrtograpsus affinis (Brachyura, Varunidae was obtained by culture in the laboratory. Five zoeal stages, the megalopa and the first crab are described and illustrated. Larval development from hatching to first crab took 29 days at 20° C and 35 PSU. The genus Cyrtograpsus only consists of three species. Larval development of C. altimanus and C. angulatus had been described previously. In the present study, morphological larval characters of the three species are compared. Generic larval features are also compared with those of other Varunidae genera.

  6. Occurrence of Euplatypus parallelus, Euplatypus sp. (col.: Euplatypodidae and Xyleborus affinis (col.: Scolytidae in Pinus sp. in Ribas do Rio Pardo, Mato Grosso do Sul, Brazil

    Directory of Open Access Journals (Sweden)

    Zanuncio José Cola

    2002-01-01

    Full Text Available Wood borer species of the families Euplatypodidae and Scolytidae were observed attacking trees of Pinus sp. in the Municipality of Ribas do Rio Pardo, state of Mato Grosso do Sul, Brazil, in March 2000. This plantation had been previously burned in an accidental fire in January 2000, causing the trees to become partially or totally unhealthy, rendering them more susceptible to attack of these pests. Galleries of these wood borers were opened with a chisel to observe parameters such as their direction and form of these galleries. Species observed as wood borers of Pinus sp. were Euplatypus parallelus, Euplatypus sp. (Coleoptera: Euplatypodidae and Xyleborus affinis (Coleoptera: Scolytidae.

  7. Presencia de Gambusia affinis (Baird & Girard, 1853) en un humedal boscoso del Sur de Chile. Posibles implicancias sobre la fauna local de invertebrados.

    OpenAIRE

    L. Parra-Coloma; F. Correa-Araneda

    2014-01-01

    Las especies invasoras son la principal causa de pérdida debiodiversidad del planeta, producto de la depredación que afecta a la faunalocal mediante competencia, hibridación, alteración del hábitat y transmisiónde enfermedades. En este estudio se describe la posible implicancia del pezmosquito sobre la fauna de invertebrados en un humedal boscoso presente en laregión de la Araucanía, Chile. Los resultados nos indican la presencia de Gambusia affinis en todos los sitios demuestreo, destacándos...

  8. Copepod grazing and their impact on phytoplankton standing stock and production in a tropical coastal water during the different seasons

    Digital Repository Service at National Institute of Oceanography (India)

    Jagadeesan, L.; Jyothibabu, R.; Arunpandi, N.; Parthasarathi, S.

    structure (Bautista and Harris 1992; Lee et al. 2012). Calanoid copepods showed both positive electivity on micro and nano plankton fractions (Fig.4) during low phytoplankton standing stock periods (Pre-Monsoon and Post-Monsoon), whereas they showed... on phytoplankton biomass are variable, ranging from <10% to 30% to standing stock (Morales et al. 1991; Bautista and Harris 1992; Dagg 1995; Froneman 2000; Grunewald et al. 2002; Li et al. 2003; Kibirige and Perisinotto 2003). Copepods normally consumed <30...

  9. Trophic Cascading of Medusae on the Relationships between Copepods and Diatoms in a Subtropical Coastal Ecosystem

    Directory of Open Access Journals (Sweden)

    Jia-Lu Chung

    2009-01-01

    Full Text Available To investigate the spatial and temporal variation of phytoplankton and copepods, eight seasonal cruises (January 2005 ~ Oc to ber 2006 were conducted in a subtropical coast site that encom passed 19 sampling stations. The results in dicated that the temperature (18.4 - 29.7°C varied more than 10°C seasonally, while nutrient concentrations (ni trate: 0.4 - 6.3 mM, phosphate: 0.1 - 0.8 mM, and silicate 2.1 - 12.1 mM were in versely corre lated with temperature. Diatoms (2792 - 1602437 cells m-3 constituted > 90% of the phytoplankton as semblages and dinoflagellates (226 - 10029 cells m-3 represented only ~10% of the algaebiomass. Copepod abun dance (8 - 1031 ind. m-3 varied positively with that of diatom and tempeature. Therelative abundance of Temora spp. (1 - 712 ind. m-3 varied from 69% in summer; that of Paracalanus spp. (0.1 - 176 ind. m-3 were > 25% in spring and au tumn and Calanus spp. (0.5 - 24 ind. m-3 dom i nated in win ter and spring, but ac counted for only ~10% of the to tal copepods. Both di a tom den sity and copepod abun dance were positively correlated with temperature, indicating these two plank tongroups were left bot tom-up control. The copepod abun dance positively co-aried with diatoms in 2005, but not in 2006. Fur ther sea son-to-sea son analysis showed that the diatomvs. copepodratios changed positively only when the medusa abun dance changed greatly (> 40-fold between consecutive sea sons. During periods when the medusa abundance varied less than 10-fold between seasons, there is no relationship between the ratios and the medusa abun dance. This study suggests that the stability of the medusa abundance from season to season could be important in regulating the ecological linkage between diatoms and their predators ¡V copepods.

  10. Copepod omnivory in the North Water Polynya (Baffin Bay) during autumn: spatial patterns in lipid composition

    Science.gov (United States)

    Stevens, Catherine J.; Deibel, Don; Parrish, Christopher C.

    2004-11-01

    To deduce spatial patterns in copepod lipid composition and feeding strategy (i.e., degree of omnivory) in the North Water Polynya (Baffin Bay), three dominant species were sampled extensively over a broad geographical area (∼75-78°N; 77-69°W). Calanus hyperboreus CV, C. glacialis CV and Metridia longa females were collected in shallow and deep strata at 16 stations during autumn 1999 (August-October). Principal components analysis (PCA) revealed that all species fed omnivorously in the southeastern (SE) region of the polynya. Here, copepods generally had elevated levels of carnivorous (e.g., 18 : 1 (n - 9)), dinoflagellate (e.g., 18 : 4 (n - 3) ; 22 : 6 (n - 3)) and bacterial fatty acid markers (e.g., odd-numbered and/or branched; 18:1(n - 7)). Copepods in the SE contained low proportions of diatom (e.g., 16 : 4 (n - 1) ; 20 : 5 (n - 3)) and phytoplankton (e.g., polyunsaturated fatty acids) markers, relative to animals from northwest stations. Values of the omnivory index 'UC' (i.e., unsaturation coefficient) were also low in SE copepods, which implied reduced phytoplankton ingestion. Spatial patterns in seston fatty acid composition resembled the dietary signatures in that dinoflagellate and bacterial indices were highest in SE waters. Estimates of primary production, particulate organic carbon, carbon to chlorophyll ratios, and abundances of diatoms, dinoflagellates and bacteria, provided further evidence of the importance of the microbial loop at SE stations. Comparable spatial patterns in feeding strategy were observed in both sampling layers, indicating that copepods from the entire water column were feeding on a similar food source. Several interesting species-specific trends also emerged from the PCA. In general, C. hyperboreus fed the most herbivorously, followed by C. glacialis and M. longa. C. glacialis showed a stronger connection to the microbial food web than the other two species, and M. longa fed herbivorously throughout much of the polynya

  11. [Biological process of phosphorus turnover in surface water body of Xiamen Harbor. II: Grazing pressure of copepod on phytoplankton].

    Science.gov (United States)

    Yang, Wei-di; Yang, Qing; Lin, Yuan-shao; Cao, Wen-qing

    2008-12-01

    To understand the roles of copepod in the biogeochemical cycling of phosphorus, gut fluorescence method was applied to examine in situ the grazing rate of copepod on the phytoplankton in Xiamen Time Station (XMTS) in May, August and November 2005 and March 2006. In the meanwhile, the abundance and species composition of copepod were investigated, and the grazing pressure of copepod on the phytoplankton was estimated. The results showed that the annual average grazing rate of copepod was 55.53 microg x m(-3) x d(-1), being the highest (108.98 microg x m(-3) x d(-1)) in autumn and the lowest (7.18 microg x m(-3) x d(-1)) in summer. Based on the estimation from our experimental data, the daily grazing rate of copepod populations on the phytoplankton in Xiamen Harbor was, on annual average, about 1.81% of the phytoplankton's standing stock, with the values in spring, summer, autumn, and winter being 3.22%, 0.06%, 3.52% and 0.46%, respectively.

  12. RNA-seq based whole transcriptome analysis of the cyclopoid copepod Paracyclopina nana focusing on xenobiotics metabolism.

    Science.gov (United States)

    Lee, Bo-Young; Kim, Hui-Su; Choi, Beom-Soon; Hwang, Dae-Sik; Choi, Ah Young; Han, Jeonghoon; Won, Eun-Ji; Choi, Ik-Young; Lee, Seung-Hwi; Om, Ae-Son; Park, Heum Gi; Lee, Jae-Seong

    2015-09-01

    Copepods are among the most abundant taxa in marine invertebrates, and cyclopoid copepods include more than 1500 species and subspecies. In marine ecosystems, planktonic copepods play a significant role as food resources in the food web and sensitively respond to environmental changes. The copepod Paracylopina nana is one of the planktonic brackish water copepods and considered as a promising model species in ecotoxicology. We sequenced the whole transcriptome of P. nana using RNA-seq technology. De novo sequence assembly by Trinity integrated with TransDecoder produced 67,179 contigs including putative alternative spliced variants. A total of 12,474 genes were identified based on BLAST analysis, and gene sequences were most similar to the sequences of the branchiopod Daphnia. Gene Ontology and KEGG pathway analysis showed that most transcripts annotated were involved in pathways of various metabolisms, immune system, signal transduction, and translation. Considering numbers of sequences and enzymes involved in the pathways, particularly attention was paid to genes potentially involved in xenobiotics biodegradation and metabolism. With regard to xenobiotics metabolism, various xenobiotic metabolizing enzymes such as oxidases, dehydrogenases, and transferases were obtained from the annotated transcripts. The whole transcriptome analysis of P. nana provides valuable resources for future studies of xenobiotics-related metabolism in this marine copepod species.

  13. Predator-prey interactions and community structure: chironomids, mosquitoes and copepods in Heliconia imbricata (Musaceae).

    Science.gov (United States)

    Naeem, Shahid

    1988-11-01

    Evidence from both field observations and experimental work indicates that predation by larvae of a midge, Pentaneura n. sp. (Chironomidae), causes the low densities of mosquito larvae (Culicidae) found in the water filled bracts of Heliconia imbricata (Musaceae), microhabitats typically colonized by mosquitoes. This predation affects 2 species of mosquitoes, Wyeomyia pseudopecten, a resident species, and Trichoprosopon digitatum, a non-resident species. Predation keeps resident mosquito densities low while completely excluding the nonresident mosquito from the habitat. Both these effects of predation depend on the presence of an abundant alternative prey, an undescribed species of harpacticoid copepod found in the bracts. These copepod prey sustain chironomids when resident mosquito densities are low, permiting predator densities to remain high enough to exclude the non-resident mosquito. I discuss the evolutionary and ecological implications of predation structuring communities.

  14. Unsteady motion: escape jumps in planktonic copepods, their kinematics and energetics

    DEFF Research Database (Denmark)

    Kiørboe, Thomas; Andersen, Anders Peter; Langlois, Vincent J.;

    2010-01-01

    estimate the force and power output needed to accelerate and overcome drag. Both are very high compared with those of other organisms, as are the escape velocities in comparison to startle velocities of other aquatic animals. Thus, the maximum weight-specific force, which for muscle motors of other animals...... has been found to be near constant at 57 N (kg muscle)−1, is more than an order of magnitude higher for the escaping copepods. We argue that this is feasible because most copepods have different systems for steady propulsion (feeding appendages) and intensive escapes (swimming legs), with the muscular...... arrangement of the latter probably adapted for high force production during short-lasting bursts. The resulting escape velocities scale with body length to power 0.65, different from the size-scaling of both similar sized and larger animals moving at constant velocity, but similar to that found for startle...

  15. Mating success and sexual selection in a pelagic copepod, Temora longicornis: Evidence from paternity analyses

    DEFF Research Database (Denmark)

    Sichlau, Mie Hylstofte; Eg Nielsen, Einar; Thygesen, Uffe Høgsbro;

    2015-01-01

    Knowledge about mating patterns is essential for understanding and explaining rates of reproduction and genetic potential of copepods populations. The aim of this study was to examine (1) the occurrence of multiple paternity in Temora longicornis, (2) the effect of multiple paternity (if present......) on the females reproductive output, and (3) whether mating is random or some individuals have a higher than average chance of fertilizing or being fertilized (super individuals). We show that multiple paternity is common in this copepod species, that females benefit from multiple matings by increased offspring...... production, and that a relatively small fraction of the males and females in a population account for most of the offspring production. In both males and females, mating is nonrandom. Superior individuals with a higher than average matings success were identified both among females and among males....

  16. Species-specific vulnerability of Arctic copepods to oil contamination and global warming

    DEFF Research Database (Denmark)

    Dinh, Khuong Van; Nielsen, Torkel Gissel

    Arctic ecosystems are predicted to have more severe effects from global warming as during the last decades the temperatures have increased in this region at a rate of 2-4 times higher than the global average. In addition, oil exploitation and shipping activities in the Arctic are predicted...... to increase under global warming as the result of the retreat of sea ice, posing the risk of oil contamination. It is poorly known how cold adapted copepods in the Arctic deal with the combined effects of global warming and oil exposure. To address this, we exposed females of two copepods species Calanus...... of temperatures. Notably, exposure to high pyrene resulted in ca. 70% of mortality in C. finmarchicus, the species with North Atlantic Origin, that was two times higher than the mortality observed for C. glacialis, the true Arctic species. These results suggest that extreme temperature under global warming...

  17. Phytoplankton growth rate and nitrogen content: Implications for feeding and fecundity in a herbivorous copepod

    DEFF Research Database (Denmark)

    Kiørboe, Thomas

    1989-01-01

    at a concentration of 1.5 ppm. Over more than 2 orders of magnitude increase in algal growth rate, the ingested cell volume increased by less than a factor of 2, ingested carbon remained constant whereas ingested nitrogen as well as rate of egg production increased by a factor of ca 6. Variation in ingested cell......Observations of natural feeding and egg-production rates of planktonic copepods have revealed distinct responses, independent of phytoplankton biomass, to oceanographic processes that fertilize the photic layer. Are such responses caused by changes in phytoplankton growth rate, influencing feeding...... behaviour, and/or by changes in the chemical composition of the phytoplankton, influencing fecundity? The diatom Thalassiosira weissflogii, grown in continuous cultures at different dilution rates and different nitrogen concentrations in the growth medium, was offered to the copepod Acartia tonsa...

  18. Planktivorous feeding in calm and turbulent environments, with emphasis on copepods

    DEFF Research Database (Denmark)

    Kiørboe, Thomas; Saiz, E.

    1995-01-01

    feeding copepods, such as Acartidae and many cyclopoids, turbulence has a dominant influence on prey encounter rates. The effect on cruising predators is intermediate. Application of the models to situations examined experimentally demonstrates a high predictive performance. Finally we explore and model...... the potentially negative effects of turbulence on copepod feeding currents, prey perception and capture success. At typical and even high turbulent intensities, none of these is significantly affected....... the levels of turbulence (as dissipation rate) at which ambient fluid motion is important in enhancing prey encounter rates for various types of predators (e.g, ambush and cruise predators, suspension feeders). Generally, turbulence has the largest effect on prey encounters for predators with low motility...

  19. High turnover rates of copepod fecal pellets due to Noctiluca scintillans grazing

    DEFF Research Database (Denmark)

    Kiørboe, Thomas

    2003-01-01

    Copepod fecal pellet production and vertical flux, as well as vertical distributions of copepods, fecal pellets and the heterotrophic dinoflagellate Noctiluca scintillans were monitored in an upwelling plume off the coast of Brazil during 5 d in austral spring. Less than half (20 to 45......%) of the pellets produced in the overlying water column reached sediment traps positioned at 30 to 60 m depth, and specific sinking losses computed from steady-state considerations varied inversely with trap depth between 0.3 and 2.9 d-1. Total specific losses varied between 0.6 and 16 d-1, and the major part...... as the latter aged, up to 5 x 105 cells m-2, and fecal pellets occurred commonly in the food vacuoles of N. scintillans. Specific fecal pellet remineralization rates were linearly related to the abundance of N. scintillans. This relation can be quantitatively accounted for if N. scintillans clears the water...

  20. Population dynamic of high latitude copepods - with emphasis on Metridia longa

    DEFF Research Database (Denmark)

    Kjellerup, Sanne

    2014-01-01

    High latitude ecosystems are shaped by seasonality in light, ranging from complete darkness in winter to midnight sun in summer, influencing both temperature and primary production. Copepods are important grazers on phytoplankton in marine systems and occupy a central role in the marine food......, sampling only the upper water column during the day-as is a usual procedure-would underestimate this potential key species. Reproduction patterns of the large calanoids suggested lifecycles adapted to the seasonal and episodic food availability, and consequently had a pulsed reproduction. In contrast......, small copepod species were less dependent on the spring phytoplankton bloom, and their reproduction and population dynamics were less pulsed. Likewise, a large proportion of Oithona similis was ovigerous from March to August. Reproduction of Microsetella norvegica, another of the small key species...

  1. Zooplankton distribution across Fram Strait in autumn: Are small copepods and protozooplankton important?

    Science.gov (United States)

    Svensen, Camilla; Seuthe, Lena; Vasilyeva, Yulia; Pasternak, Anna; Hansen, Edmond

    2011-12-01

    We investigated zooplankton distribution in September 2006/2007 at eight stations across Fram Strait in contrasting water masses ranging from cold Polar water to warm Atlantic water. Our main objectives were: (1) to describe the plankton community in the upper 200 m during autumn, and (2) to investigate the importance of small-sized copepods and protozooplankton in an arctic ecosystem when the majority of the large Calanus species had entered diapause. We sampled both with a WP-2 net and Go-Flo bottle and show that small copepods food. Heterotrophic protozooplankton, on the other hand, were most likely bottom-up regulated by the availability of phytoplankton food and conclude that there was a strong link between the zooplankton community and the microbial food web in Fram Strait.

  2. Mosquitofish (Gambusia affinis preference and behavioral response to animated images of conspecifics altered in their color, aspect ratio, and swimming depth.

    Directory of Open Access Journals (Sweden)

    Giovanni Polverino

    Full Text Available Mosquitofish (Gambusia affinis is an example of a freshwater fish species whose remarkable diffusion outside its native range has led to it being placed on the list of the world's hundred worst invasive alien species (International Union for Conservation of Nature. Here, we investigate mosquitofish shoaling tendency using a dichotomous choice test in which computer-animated images of their conspecifics are altered in color, aspect ratio, and swimming level in the water column. Pairs of virtual stimuli are systematically presented to focal subjects to evaluate their attractiveness and the effect on fish behavior. Mosquitofish respond differentially to some of these stimuli showing preference for conspecifics with enhanced yellow pigmentation while exhibiting highly varying locomotory patterns. Our results suggest that computer-animated images can be used to understand the factors that regulate the social dynamics of shoals of Gambusia affinis. Such knowledge may inform the design of control plans and open new avenues in conservation and protection of endangered animal species.

  3. Influence of Kuroshio water on the annual copepod community structure in an estuary in the northwest Pacific Ocean

    Science.gov (United States)

    Tseng, Li-Chun; Hsiao, Shih-Hui; Sarkar, Santosh Kumar; Bhattacharya, Bhaskar Deb; Chen, Qing-Chao; Hwang, Jiang-Shiou

    2016-04-01

    The influence of Kuroshio water on temporal distribution and copepod diversity was investigated in the Lanyang River estuary (LRE), the longest river in northeast Taiwan, to assess secondary productivity. Zooplankton samples were collected bimonthly from the surface waters (0-2 m) of the estuary during cruises in 2006. Hydrological parameters indicated that the water in the LRE was an admixture of the Lanyang River water and seawater. Among the different genera, 47 copepod species (including 10 species that were identified only to the generic level) belonging to 28 genera, 16 families, and 4 orders were identified. The abundance and proportion of copepods to the total zooplankton counts range from 0 to 3683.42 (304.9±692.7 individuals m-3) and from 0 to 100 (55.09±34.84%) respectively. The copepod community structure revealed a distinct seasonal succession and showed significant differences among the sampling cruises (pANOVA). The 5 most abundant species were Parvocalanus crassirostris (relative abundance [RA]: 50.93%), Pseudodiaptomus serricaudatus (RA: 16.85%), Euterpina acutifrons (RA: 7.34%), Cyclops vicinus (RA: 4.82%), and Microcyclops tricolor (RA: 3.15%). The abundance, species number, indices of richness, evenness, and copepod diversity varied significantly (pANOVA) for all the cruises. Pearson correlation analysis results demonstrated that salinity was positively correlated with the copepod species number (r=0.637), total copepod abundance (r=0.456), and Shannon-Wiener diversity index (r=0.375) with a 1% level of significance. By contrast, the evenness index was negatively correlated with salinity (r=-0.375, p=0.01), indicating that copepod diversity in the LRE was influenced mainly by seawater. The Kuroshio Current played a major role in transporting and distributing warm-water copepods to its affected area. Copepod species assemblages showed seasonal succession and varied drastically with tidal change. The latter registered high abundance, and the

  4. Produced water components: uptake kinetics and effects on the metabolism of the Arctic copepod Calanus glacialis

    OpenAIRE

    Bergentz, Sara Hanna Amalia

    2016-01-01

    The oil exploration and search for new oil production fields is expanding further north and has reached the Arctic. Oil drilling activities release large amounts of produced water (PW) to the marine environment and sub-lethal effects on biota cannot be excluded. The polycyclic aromatic hydrocarbons (PAHs) present in PW have previously been shown to exhibit negative effects on growth, development and survival of aquatic organisms. The Arctic copepod Calanus glacialis is an abundant zooplankton...

  5. Electrophoretic protein profiles of mid-sized copepod Calanoides patagoniensis steadily fed bloom-forming diatoms

    Directory of Open Access Journals (Sweden)

    Victor M Aguilera

    2015-09-01

    Full Text Available Recent field and experimental evidence collected in the southern upwelling region off Concepción (36°5'S, 73°3'W showed an abrupt reduction (<72 h in the egg production rates (EPR of copepods when they were fed steadily and solely with the local bloom-forming diatom Thalassiosira rotula. Because diatoms were biochemically similar to dinoflagellate Prorocentrum minimum, a diet which supported higher reproductive outcomes, the fecundity reduction observed in copepod females fed with the diatom may have obeyed to post-ingestive processes, giving rise to resources reallocation. This hypothesis was tested by comparing feeding (clearance and ingestion rates, reproduction (EPR and hatching success and the structure of protein profiles (i.e., number and intensity of electrophoretic bands of copepods (adults and eggs incubated during 96 h with the two food conditions. The structure of protein profiles included molecular sizes that were calculated from the relative mobility of protein standards against the logarithm of their molecular sizes. After assessing the experimental conditions, feeding decreased over time for those females fed with T. rotula, while reproduction was higher in females fed with P. minimum. Electrophoretic profiles resulted similar mostly at a banding region of 100 to 89-kDa, while they showed partial differences around the region of 56-kDa band, especially in those females fed and eggs produced with T. rotula. Due to reproductive volume was impacted while larvae viability, a physiological processes with specific and high nutritional requirements, was independent on food type; post-ingestive processes, such as expression of stress-related proteins deviating resources to metabolic processes others than reproduction, are discussed under framework of nutritional-toxic mechanisms mediating copepod-diatoms relationships in productive upwelling areas.

  6. Low fertilization rates in a pelagic copepod caused by sexual selection?

    DEFF Research Database (Denmark)

    Ceballos, Sara; Sichlau, Mie Hylstofte; Heuschele, Jan;

    2014-01-01

    random mating. Such low fertilization rates are normally related to environmental factors such as poor food or low densities, which we could not confirm in our experiment. Male density was negatively related to fertilization rate, and a large fraction of males did not mate in laboratory incubations. We...... therefore suggest that sexual selection, through mate choice or male–male competition could account for low fertilization rates of females in populations of pelagic copepods during some periods of the year...

  7. Role of dispersants of oil on copepods in high arctic areas

    DEFF Research Database (Denmark)

    Gustavson, Kim; Nørregaard, Rasmus Dyrmose; Møller, Eva Friis;

    2013-01-01

    The purpose of the project is to increase the knowledge on the effects of using dispersants on oil spills in high arctic areas: more precisely, to investigate accumulation in and effects on high arctic copepods. Such knowledge is crucial for performing a robust net environmental benefit analysis...... prior to making a decision as to whether or not dispersant may be allowed as an operational oil spill response in high arctic sea areas....

  8. Rates of ingestion and their variability between individual calanoid copepods: Direct observations

    Energy Technology Data Exchange (ETDEWEB)

    Paffenhoefer, G.A.; Lewis, K.D. [Skidaway Inst. of Oceanography, Savannah, GA (United States); Bundy, M.H. [Skidaway Inst. of Oceanography, Savannah, GA (United States)]|[Alfred-Wegener-Institut fuer Polar- und Meeresforschung, Bremerhaven (Germany). Inst. fuer Fernerkundung (IFE); Metz, C. [Alfred-Wegener-Institut fuer Polar- und Meeresforschung, Bremerhaven (Germany). Inst. fuer Fernerkundung (IFE)

    1995-12-01

    The goals of this study were to determine rates of ingestion and fecal pellet release, and their variability, for individual planktonic copepods over extended periods of time (>20 min). Ingestions and rejections of individual cells of the diatom Thalassiosira eccentrica by a adult females of the calanoid Paracalanus aculeatus were directly quantified by observing individual copepods continuously at cell concentrations ranging from 0.1 to 1.2 mm{sup 3} l{sup {minus}1}. Average ingestion rates increased with increasing food concentration, but were not significantly different between 0.3 and 1.0 mm{sup 3} l{sup {minus}1} (9.8 and 32.7 {mu}g Cl{sup {minus}1}) of T.eccentrica. Rates of cell rejections were low and similar at 0.1 and 0.3. but were significantly higher at 1.0 mm{sup 3} l{sup {minus}1}. The coefficients of variation for average ingestion rates of individual copepods hardly differed between food concentrations, ranging from 17 to 22%, and were close to those for average fecal pellet release intervals which ranged from 15 to 21%. A comparison between individuals at each food concentration found no significant differences at 1.0; at 0.1 and 0.3 mm{sup 3} l{sup {minus}1}, respectively, ingestion rates of four out of five females did not differ significantly from each other. Average intervals between fecal pellet releases were similar at 0.3 and 1.0 mm{sup 3} l{sup {minus}1}. Fecal pellet release intervals between individuals were significantly different at each food concentration; these significant differences were attributed to rather narrow ranges of pellet release intervals of each individual female. Potential sources/causes of variability in the sizes and rates of copepods in the ocean are evaluated.

  9. Synopsis of lichomolgid copepods (Poecilostomatoida) associated with soft corals (Alcyonacea) in the tropical Indo-Pacific

    OpenAIRE

    Humes, A.G.

    1990-01-01

    A synopsis of the 97 species of lichomolgid copepods known to be associated with tropical IndoPacific shallow-water alcyonaceans is given (Madagascar, New Caledonia, Moluccas, Philippines, and Enewetak Atoll). One new genus and 29 new species are included, distributed among the lichomolgid genera Acanthomolgus (2 new species), Alcyonomolgus (1), Colobomolgus (2), Critomolgus (3), Doridicola (5), Paradoridicola (7), Paramolgus (8), and Telestacicola (1). The alcyonacean hosts, numbering more t...

  10. Ammonium excretion and oxygen respiration of tropical copepods and euphausiids exposed to oxygen minimum zone conditions

    Directory of Open Access Journals (Sweden)

    R. Kiko

    2015-10-01

    Full Text Available Calanoid copepods and euphausiids are key components of marine zooplankton communities worldwide. Most euphausiids and several copepod species perform diel vertical migrations (DVMs that contribute to the export of particulate and dissolved matter to midwater depths. In vast areas of the global ocean, and in particular in the eastern tropical Atlantic and Pacific, the daytime distribution depth of many migrating organisms corresponds to the core of the oxygen minimum zone (OMZ. At depth, the animals experience reduced temperature and oxygen partial pressure (pO2 and an increased carbon dioxide partial pressure (pCO2 compared to their near-surface nighttime habitat. Although it is well known that low oxygen levels can inhibit respiratory activity, the respiration response of tropical copepods and euphausiids to relevant pCO2, pO2 and temperature conditions remains poorly parameterized. Further, the regulation of ammonium excretion at OMZ conditions is generally not well understood. It was recently estimated that DVM-mediated ammonium supply considerably fuels bacterial anaerobic ammonium oxidation – a major loss process for fixed nitrogen in the ocean. These estimates were based on the implicit assumption that hypoxia or anoxia in combination with hypercapnia (elevated pCO2 does not result in a downregulation of ammonium excretion. Here we show that exposure to OMZ conditions can result in strong depression of respiration and ammonium excretion in calanoid copepods and euphausiids from the Eastern Tropical North Atlantic and the Eastern Tropical South Pacific. These physiological responses need to be taken into account when estimating DVM-mediated fluxes of carbon and nitrogen into OMZs.

  11. Heritability of Sex Tendency in a Harpacticoid Copepod, Tigriopus californicus

    OpenAIRE

    Voordouw, Maarten J; Anholt, Bradley R.

    2011-01-01

    Systems with genetic variation for the primary sex ratio are important for testing sex-ratio theory and for understanding how this variation is maintained. Evidence is presented for heritable variation of the primary sex ratio in the harpacticoid copepod Tigriopus californicus. Variation in the primary sex ratio among families cannot be accounted for by Mendelian segregation of sex chromosomes. The covariance in sex phenotype between full-sibling clutches and between mothers and offspring sug...

  12. The Genetic Basis of Local Adaptation to Thermal Stress in the Intertidal Copepod Tigriopus Californicus /

    OpenAIRE

    Sefton, Margaret Marie

    2013-01-01

    Populations of the intertidal copepod, Tigriopus californicus, vary in their tolerance to thermal stress. In this study, the genetic basis of these differences was examined by generating interpopulation hybrids between a northern and southern population; hybrids were then exposed them to multiple generations of heat stress. At each generation, changes in allele frequency of six candidate genes were monitored. Although allelic frequencies did not change in response to thermal stress, there was...

  13. Recombination in interpopulation hybrids of the copepod Tigriopus californicus: release of beneficial variation despite hybrid breakdown.

    Science.gov (United States)

    Edmands, Suzanne

    2008-01-01

    Crosses between divergent populations of the copepod Tigriopus californicus typically result in fitness reductions for both F2 and backcross hybrids. Because females in this species lack chiasmatic meiosis, both recombinant and nonrecombinant backcross hybrids can be created. Recombinant hybrids were found to have significantly faster development time for both males and females in 2 pairs of crosses, indicating the creation of favorable gene combinations by disrupting parental linkage groups.

  14. Evolutionary genetics of hybrid breakdown in the marine copepod Tigriopus californicus

    OpenAIRE

    Ellison, Christopher K

    2008-01-01

    Populations of the supra-littoral marine copepod Tigriopus californicus are known to be highly divergent and to exhibit a pattern of hybrid breakdown when crossed under laboratory conditions. This dissertation examines the genetic mechanisms involved in hybrid breakdown in T. californicus, particularly those involving integration of the nuclear and mitochondrial genomes. In Chapter I, I summarize some of the relevant literature concerning the importance of hybrid breakdown to evolutionary bio...

  15. A gene-based SNP resource and linkage map for the copepod Tigriopus californicus

    OpenAIRE

    Foley Brad R; Rose Colin G; Rundle Daniel E; Leong Wai; Moy Gary W; Burton Ronald S; Edmands Suzanne

    2011-01-01

    Abstract Background As yet, few genomic resources have been developed in crustaceans. This lack is particularly evident in Copepoda, given the extraordinary numerical abundance, and taxonomic and ecological diversity of this group. Tigriopus californicus is ideally suited to serve as a genetic model copepod and has been the subject of extensive work in environmental stress and reproductive isolation. Accordingly, we set out to develop a broadly-useful panel of genetic markers and to construct...

  16. Growth and production of the copepod community in the southern area of the Humboldt Current System

    Directory of Open Access Journals (Sweden)

    R. Escribano

    2015-02-01

    Full Text Available Zooplankton production is a critical issue for understanding marine ecosystem structure and dynamics, however, its time-space variations are mostly unknown in most systems. In this study, estimates of copepod growth and production (CP in the coastal upwelling and coastal transition zones off central-southern Chile (∼35–37° S were obtained from annual cycles during a 3 year time series (2004, 2005, and 2006 at a fixed shelf station and from spring–summer surveys during the same years. C-specific growth rates (g varied extensively among species and under variable environmental conditions; however, g values were not correlated to either near surface temperature or copepod size. Copepod biomass (CB and CP were higher within the coastal upwelling zone (−2 year−1 with a~mean annual P/B ratio of 2.7. We estimated that CP could consume up to 60% of the annual primary production (PP in the upwelling zone but most of the time is around 8%. Interannual changes in CB and CP values were associated with changes in the copepod community structure, the dominance of large-sized forms replaced by small-sized species from 2004 to 2006. This change was accompanied by more persistent and time extended upwelling during the same seasonal period. Extended upwelling may have caused large losses of CB from the upwelling zone due to an increase in offshore advection of coastal plankton. On a larger scale, these results suggest that climate-related impacts of increasing wind-driven upwelling in coastal upwelling systems may generate a negative trend in zooplankton biomass.

  17. Foraging mode and prey size spectra of suspension-feeding copepods and other zooplankton

    DEFF Research Database (Denmark)

    Kiørboe, Thomas

    2016-01-01

    Prey size spectra of suspension-feeding zooplankton may be predicted from foraging mode and a mechanistic understanding of prey perception and capture. I examine this for suspension-feeding copepods where 2 foraging modes can be distinguished: ambush feeding and active (i.e. cruising and feeding...... the prediction. I also make qualitative predictions of food size spectra in zooplankton with other prey perception mechanisms that accord with observations....

  18. Influence of projected ocean warming on population growth potential in two North Atlantic copepod species

    Science.gov (United States)

    Stegert, Christoph; Ji, Rubao; Davis, Cabell S.

    2010-10-01

    Copepods of the genera Pseudocalanus and Centropages play an important role in the North Atlantic ecosystems and have distinctive spatial and temporal patterns depending on physiological adaptation to different environmental conditions. To examine the possible impact of climate change on these biogeographic patterns, potential population growth rate was computed for each species using IPCC projections of sea surface temperature together with chlorophyll distributions from SeaWiFS climatology and published laboratory data on temperature and food-dependent life-history parameters. The results indicate that the predicted temperature increase throughout the North Atlantic will cause temporal and spatial shifts in copepod species population growth potential. The Centropages population is projected to increase in mid-latitudinal shelf areas, e.g. the Gulf of Maine and the North Sea, due to shorter generation times and a longer growing season, while Pseudocalanus is predicted to be less abundant in these regions after 2050. These shifts potentially have a significant impact on the future demographics of pelagic fish species for which the copepods are the major food source.

  19. First record of Neoergasilus japonicus (Poecilostomatoida: Ergasilidae), a parasitic copepod new to the Laurentian Great Lakes

    Science.gov (United States)

    Hudson, Patrick L.; Bowen, Charles A.

    2002-01-01

    The parasitic copepod Neoergasilus japonicus, native to eastern Asia, was first collected from 4 species of fish (fathead minnow, Pimephales promelas; largemouth bass, Micropterus salmoides; pumpkinseed sunfish, Lepomis gibbosus; and yellow perch, Perca flavescens) in July 1994 in Saginaw Bay, Lake Huron, Michigan. Further sampling in the bay in 2001 revealed infections on 7 additional species (bluegill, Lepomis macrochirus; carp, Cyprinus carpio; channel catfish, Ictalurus punctatus; goldfish, Carassius auratus; green sunfish, Lepomis cyanellus; rock bass, Ambloplites rupestris; and smallmouth bass, Micropterus dolomieu). An additional 21 species examined in 2001 were devoid of the parasite. A limited collection of fish from Lake Superior (n = 8) and Lake Michigan (n = 46) in 1994 showed no infection. Neoergasilus japonicus is most frequently found attached to the dorsal fin and, in decreasing frequency, on the anal, tail, pelvic, and pectoral fins. Prevalence generally ranged from 15 to 70 and intensity from 1 to 10. The greatest number of copepods on a single host was 44. The copepod Neoergasilus japonicus appears to disperse over long distances rather quickly, spreading across Europe in 20 yr and then moving on to North America over a span of 10 yr. Its main vehicle of transport and introduction into the Great Lakes is probably exotic fish hosts associated with the fish-culture industry.

  20. First report of ciliate (Protozoa) epibionts on deep-sea harpacticoid copepods

    Science.gov (United States)

    Sedlacek, Linda; Thistle, David; Fernandez-Leborans, Gregorio; Carman, Kevin R.; Barry, James P.

    2013-08-01

    We report the first observations of ciliate epibionts on deep-sea, benthic harpacticoid copepods. One ciliate epibiont species belonged to class Karyorelictea, one to subclass Suctoria, and one to subclass Peritrichia. Our samples came from the continental rise off central California (36.709°N, 123.523°W, 3607 m depth). We found that adult harpacticoids carried ciliate epibionts significantly more frequently than did subadult copepodids. The reason for the pattern is unknown, but it may involve differences between adults and subadult copepodids in size or in time spent swimming. We also found that the ciliate epibiont species occurred unusually frequently on the adults of two species of harpacticoid copepod; a third harpacticoid species just failed the significance test. When we ranked the 57 harpacticoid species in our samples in order of abundance, three species identified were, as a group, significantly more abundant than expected by chance if one assumes that the abundance of the group and the presence of ciliate epibionts on them were uncorrelated. High abundance may be among the reasons a harpacticoid species carries a ciliate epibiont species disproportionately frequently. For the combinations of harpacticoid species and ciliate epibiont species identified, we found one in which males and females differed significantly in the proportion that carried epibionts. Such a sex bias has also been reported for shallow-water, calanoid copepods.

  1. Fitness costs and benefits of ultraviolet radiation exposure in marine pelagic copepods

    DEFF Research Database (Denmark)

    Hylander, Samuel; Grenvald, Julie Cornelius; Kiørboe, Thomas

    2014-01-01

    Life-history theory predicts that organisms should allocate energy throughout their life such that they maximize their fitness. Copepod zooplankton are known to accumulate sunscreens (so-called mycosporine-like amino acids, MAAs) and antioxidant carotenoids to mitigate negative effects of ultravi......Life-history theory predicts that organisms should allocate energy throughout their life such that they maximize their fitness. Copepod zooplankton are known to accumulate sunscreens (so-called mycosporine-like amino acids, MAAs) and antioxidant carotenoids to mitigate negative effects...... of ultraviolet radiation (UVR), but it is not well known how this affects their fitness. We followed cohorts of the marine copepod Acartia tonsa and assessed how fitness was affected by UVR exposure and a diet rich in UVR-protective sunscreens. Several fitness components including somatic growth, egg quality...... and nauplii production (larvae) were negatively affected by UVR, whereas other components such as size at maturity, survival and length of life were not. Nauplii production through low egg quality was the most influential life-history parameter that changed in response to UVR. There was interaction between...

  2. Size-dependent effects of micro polystyrene particles in the marine copepod Tigriopus japonicus.

    Science.gov (United States)

    Lee, Kyun-Woo; Shim, Won Joon; Kwon, Oh Youn; Kang, Jung-Hoon

    2013-10-01

    We investigated the effects of three sizes of polystyrene (PS) microbeads (0.05, 0.5, and 6-μm diameter) on the survival, development, and fecundity of the copepod Tigriopus japonicus using acute and chronic toxicity tests. T. japonicus ingested and egested all three sizes of PS beads used and exhibited no selective feeding when phytoplankton were added. The copepods (nauplius and adult females) survived all sizes of PS beads and the various concentrations tested in the acute toxicity test for 96 h. In the two-generation chronic toxicity test, 0.05-μm PS beads at a concentration greater than 12.5 μg/mL caused the mortality of nauplii and copepodites in the F0 generation and even triggered mortality at a concentration of 1.25 μg/mL in the next generation. In the 0.5-μm PS bead treatment, despite there being no significant effect on the F0 generation, the highest concentration (25 μg/mL) induced a significant decrease in survival compared with the control population in the F1 generation. The 6-μm PS beads did not affect the survival of T. japonicus over two generations. The 0.5- and 6-μm PS beads caused a significant decrease in fecundity at all concentrations. These results suggest that microplastics such as micro- or nanosized PS beads may have negative impacts on marine copepods.

  3. Occurrence and distribution of copepods (Crustacea in the epipelagial off southern Brazil

    Directory of Open Access Journals (Sweden)

    Antonio Frederico Campaner

    1985-01-01

    Full Text Available The copepods of plankton samples collected with a Bongo net of 0.333 mm mesh in 66 oceanographic stations of 4 transects off the States of Rio de Janeiro (RJ and Santa Catarina (SC in Nov./Dec. 75 and May 76 were qualitatively and quantitatively studied. An amount of 173 species was identified, of which Paivella naporai Wheeler, Xanthocalanus marlyae Campaner, and Corycaeus giesbrechti F. Dahl were taxonomically reviewed. Frequency and density of each species, and absolute and mean density of total copepods were determined for every station, as well as frequency of adult females and males, and young forms. Abundance was higher in the neritic than in the oceanic zone, the mean density being twice greater of the neritic zone of RJ than in that of SC and almost identical in the oceanic zone off both States except for SC in Nov./Dec. 75, where values were thrice greater than in RJ. These results were related to the distribution of water masses in the sampling areas. Copepod associations were determined for neritic and oceanic zones off the States of RJ and SC at both sampling seasons.

  4. Transcriptome sequencing and de novo analysis of the copepod Calanus sinicus using 454 GS FLX.

    Directory of Open Access Journals (Sweden)

    Juan Ning

    Full Text Available BACKGROUND: Despite their species abundance and primary economic importance, genomic information about copepods is still limited. In particular, genomic resources are lacking for the copepod Calanus sinicus, which is a dominant species in the coastal waters of East Asia. In this study, we performed de novo transcriptome sequencing to produce a large number of expressed sequence tags for the copepod C. sinicus. RESULTS: Copepodid larvae and adults were used as the basic material for transcriptome sequencing. Using 454 pyrosequencing, a total of 1,470,799 reads were obtained, which were assembled into 56,809 high quality expressed sequence tags. Based on their sequence similarity to known proteins, about 14,000 different genes were identified, including members of all major conserved signaling pathways. Transcripts that were putatively involved with growth, lipid metabolism, molting, and diapause were also identified among these genes. Differentially expressed genes related to several processes were found in C. sinicus copepodid larvae and adults. We detected 284,154 single nucleotide polymorphisms (SNPs that provide a resource for gene function studies. CONCLUSION: Our data provide the most comprehensive transcriptome resource available for C. sinicus. This resource allowed us to identify genes associated with primary physiological processes and SNPs in coding regions, which facilitated the quantitative analysis of differential gene expression. These data should provide foundation for future genetic and genomic studies of this and related species.

  5. New records of parasitic copepods (Crustacea, Copepoda) from marine fishes in the Argentinean Sea.

    Science.gov (United States)

    Paula, Cantatore Delfina María; Elizabeth, Braicovich Paola; Julia, Alarcos Ana; Laura, Lanfranchi Ana; Alejandra, Rossin María; Gustavo, Vales Damián; Tomás, Timi Juan

    2012-03-01

    Increasing knowledge of the biodiversity of parasitic copepods in the Argentinean Sea will provide a baseline against which changes in the distribution of marine biota can be detected. We provide new information on the distribution of 13 known species of parasitic copepods gathered from 11 species of marine fishes from Argentinean Sea, including 7 new host records and 9 new locality records. These species are: Bomolochus globiceps (Vervoort et Ramírez, 1968) and Nothobomolochus cresseyi Timi et Sardella, 1997 (Bomolochidae Sumpf, 1871); Brasilochondria riograndensis Thatcher et Pereira, 2004 (Chondracanthidae Milne Edwards, 1840); Taeniacanthus lagocephali Pearse, 1952 (Taeniacanthidae Wilson, 1911); Caligus rogercresseyi Boxshall et Bravo, 2000 and Metacaligus uruguayensis (Thomsen, 1949) (Caligidae Burmeister, 1835); Hatschekia conifera Yamaguti, 1939 (Hatschekiidae Kabata, 1979); Clavellotis pagri (Krøyer, 1863), Clavella adunca (Strøm, 1762), Clavella bowmani Kabata, 1963 and Parabrachiella amphipacifica Ho, 1982 (Lernaeopodidae Milne Edwards, 1840), and Lernanthropus leidyi Wilson, 1922 and Lernanthropus caudatus Wilson, 1922 (Lernanthropidae Kabata, 1979). A list of host species lacking parasitic copepods, for which large samples were investigated by the authors, is also provided in order to compare in future surveys.

  6. Inhibition of larval development of the marine copepod Acartia tonsa by four synthetic musk substances.

    Science.gov (United States)

    Wollenberger, Leah; Breitholtz, Magnus; Ole Kusk, Kresten; Bengtsson, Bengt Erik

    2003-04-15

    A nitro musk (musk ketone) and three polycyclic musks (Tonalide, Galaxolide and Celestolide) were tested for acute and subchronic effects on a marine crustacean, the calanoid copepod Acartia tonsa. Sublethal effects on A. tonsa larvae were investigated with a rapid and cost effective bioassay, which is based on the easily detectable morphological change from the last nauplius to the first copepodite stage during copepod larval development. The inhibition of larval development after 5 days exposure was a very sensitive endpoint, with 5-d-EC(50)-values as low as 0.026 mg/l (Tonalide), 0.059 mg/l (Galaxolide), 0.066 mg/l (musk ketone) and 0.160 mg/l (Celestolide), respectively. These values were generally more than one order of magnitude below the 48-h-LC(50)-values found for adults, which were 0.47 mg/l (Galaxolide), 0.71 mg/l (Celestolide), 1.32 mg/l (musk ketone) and 2.5 mg/l (Tonalide). Since the synthetic musks strongly inhibited larval development in A. tonsa at low nominal concentrations, they should be considered as very toxic. The larval development test with A. tonsa is able to provide important aquatic toxicity data for the evaluation of synthetic musks, for which there is little published ecotoxicological information available regarding Crustacea. It is suggested that subchronic and chronic copepod toxicity tests should be used more frequently for risk assessment of environmental pollutants.

  7. Deleterious epistatic interactions between electron transport system protein-coding loci in the copepod Tigriopus californicus.

    Science.gov (United States)

    Willett, Christopher S

    2006-07-01

    The nature of epistatic interactions between genes encoding interacting proteins in hybrid organisms can have important implications for the evolution of postzygotic reproductive isolation and speciation. At this point very little is known about the fitness differences caused by specific closely interacting but evolutionarily divergent proteins in hybrids between populations or species. The intertidal copepod Tigriopus californicus provides an excellent model in which to study such interactions because the species range includes numerous genetically divergent populations that are still capable of being crossed in the laboratory. Here, the effect on fitness due to the interactions of three complex III proteins of the electron transport system in F2 hybrid copepods resulting from crosses of a pair of divergent populations is examined. Significant deviations from Mendelian inheritance are observed for each of the three genes in F2 hybrid adults but not in nauplii (larvae). The two-way interactions between these genes also have a significant impact upon the viability of these hybrid copepods. Dominance appears to play an important role in mediating the interactions between these loci as deviations are caused by heterozygote/homozygote deleterious interactions. These results suggest that the fitness consequences of the interactions of these three complex III-associated genes could influence reproductive isolation in this system.

  8. Identification and molecular characterization of nitric oxide synthase (NOS) gene in the intertidal copepod Tigriopus japonicus.

    Science.gov (United States)

    Jeong, Chang-Bum; Kang, Hye-Min; Seo, Jung Soo; Park, Heum Gi; Rhee, Jae-Sung; Lee, Jae-Seong

    2016-02-10

    In copepods, no information has been reported on the structure or molecular characterization of the nitric oxide synthase (NOS) gene. In the intertidal copepod Tigriopus japonicus, we identified a NOS gene that is involved in immune responses of vertebrates and invertebrates. In silico analyses revealed that nitric oxide (NO) synthase domains, such as the oxygenase and reductase domains, are highly conserved in the T. japonicus NOS gene. The T. japonicus NOS gene was highly transcribed in the nauplii stages, implying that it plays a role in protecting the host during the early developmental stages. To examine the involvement of the T. japonicus NOS gene in the innate immune response, the copepods were exposed to lipopolysaccharide (LPS) and two Vibrio sp. After exposure to different concentrations of LPS and Vibrio sp., T. japonicus NOS transcription was significantly increased over time in a dose-dependent manner, and the NO/nitrite concentration increased as well. Taken together, our findings suggest that T. japonicus NOS transcription is induced in response to an immune challenge as part of the conserved innate immunity.

  9. Acute and physical effects of water-based drilling mud in the marine copepod Calanus finmarchicus.

    Science.gov (United States)

    Farkas, Julia; Yvonne Bådsvik, Camilla; Altin, Dag; Nordtug, Trond; Olsen, Anders Johny; Hansen, Bjørn Henrik

    2017-09-11

    The aim of this study was to investigate impacts of fine particulate fraction of a commonly used barite-containing drilling mud on the pelagic filter feeding copepod Calanus finmarchicus. The results show that the tested drilling mud had a low acute toxicity on C. finmarchicus (LC50 > 320 mg/L) and that the observed toxicity was likely caused by dissolved constituents in the mud and not the particle phase containing the weighting agent barite. Further, animals were exposed to drilling mud at a concentration of 10 mg/L for 168 hr followed by a 100 hr recovery phase. A rapid uptake of drilling mud particles was observed, while the excretion was slow and incomplete even after 100 hr recovery in clean seawater. The uptake of drilling mud particles caused a significant increase in sinking velocity of copepods, indicating that uptake of drilling mud particles affected their buoyancy. Long-term exposure to low concentrations of drilling mud could therefore cause physical effects such as impacts on the animal's buoyancy which may affect the energy budget of the copepods.

  10. DESCRIPCIÓN MORFOLÓGICA DEL TUBO DIGESTIVO DE JUVENILES DE RUBIO Salminus affinis (PISCES: CHARACIDAE

    Directory of Open Access Journals (Sweden)

    Hernandez J

    2008-12-01

    Full Text Available El objetivo del estudio fue la descripción del tubo digestivo de juveniles de Rubio Salminus affinis. Se analizaron cinco juveniles con 23,6±2,6 cm de longitud total y 142,8±62,5 g de peso. Se realizó descripción topográfica y morfológica de los órganos y cortes histológicos con tinción H-E. El esófago es un órgano tubular corto de pared gruesa que representa el 7,8% de la longitud total del tubo digestivo, presenta pliegues internos que ofrecen gran capacidad de distensión permitiendo el paso de presas de gran tamaño. El estómago es una bolsa asimétrica en forma de “Y”, grande y musculosa, amplio en la porción anterior y estrecho hacia el fondo; el número de ciegos pilóricos varió entre 13 y 23 pudiendo ser monotubulares y ramificados. El intestino, con tres asas, se extiende desde el esfínter pilórico hasta el ano. Histológicamente el tubo digestivo está formado por cuatro capas: mucosa, submucosa, muscular y serosa; el epitelio de revestimiento del esófago es estratificado plano no queratinizado con células caliciformes, cambiando a simple cilíndrico mucosecretor llegando al estómago; en el estómago se encuentra epitelio simple cilíndrico mucosecretor y los ciegos pilóricos e intestino son revestidos por epitelio simple cilíndrico con células caliciformes. Tanto el valor promedio del coeficiente intestinal (0,58, como la pared distensible del estómago sugieren que el Rubio tiene un tubo digestivo propio de carnívoro y sus características histológicas presentan similitud con la mayoría de vertebrados superiores.

  11. EVALUATION OF PHYTOTOXIC EFFECT OF DELETERIOUS RHIZOBACTERIA ON THE ROOT GROWTH OF AXONOPUS AFFINIS (CHASE AND LENS ESCULENTA (MOENCH

    Directory of Open Access Journals (Sweden)

    X.J Pacheco-Hernández

    2015-11-01

    Full Text Available Las malezas ocasionan una gran pérdida en las tierras agrícolas y comúnmente, las medidas de manejo y contención de estas especies se dan con la aplicación de herbicidas, sin embargo; en años recientes se ha presentado un interés en establecer mecanismos de biocontrol seguros, con el empleo de bacterias inhibidoras del crecimiento conocidas como rizobacterias deletéreas (Deleterious rhizobacteria: DRBque se consideran generalmente como no parasíticas, y causan, de manera sutil, efectos deletéreos a través de la producción de metabolitos dañinos a las plantas. El presente trabajo tuvo como objetivo caracterizar la producción de ácido cianhídrico de pseudomonas rizobacterianas de malezas de un cultivo de alfalfa (Medicago sativa L. y evaluar el efecto fitotóxico de éstas sobre el crecimiento radical de plántulas de Axonopus affinis (Chase y Lens esculenta (Moench. De acuerdo con los resultados obtenidos con relación a la evidencia de que los aislados de pseudomonadas son rizobacterias cianogénicas y de su efecto fitotóxico medido sobre las especies vegetales bajo estudio; se sugieren a éstas como posibles agentes de biocontrol con pastos que sean considerados malezas; ya que en general se observó que inhiben su crecimiento radical; sin embargo, un enfoque particular lo tiene la rizobacteria Pseudomonas sp. A52, la cual presentó no solamente actividad como una DRB sino también como una rizobacteria promotora del crecimiento vegetal; lo que la hace más importante de analizar en cuanto a su potencial y espectro de acción; tanto para malezas monocotiledóneas como para dicotiledóneas, recomendable como un posible agente de biocontrol con actividad múltiple.

  12. DESCRIPCIÓN MORFOLÓGICA DEL TUBO DIGESTIVO DE JUVENILES DE RUBIO Salminus affinis (PISCES: CHARACIDAE

    Directory of Open Access Journals (Sweden)

    VJ ATENCIO GARCÍA

    2008-01-01

    Full Text Available El objetivo del estudio fue la descripción del tubo digestivo de juveniles de Rubio Salminus affinis. Se analizaron cinco juveniles con 23,6±2,6 cm de longitud total y 142,8±62,5 g de peso. Se realizó descripción topográfica y morfológica de los órganos y cortes histológicos con tinción H-E. El esófago es un órgano tubular corto de pared gruesa que representa el 7,8% de la longitud total del tubo digestivo, presenta pliegues internos que ofrecen gran capacidad de distensión permitiendo el paso de presas de gran tamaño. El estómago es una bolsa asimétrica en forma de “Y”, grande y musculosa, amplio en la porción anterior y estrecho hacia el fondo; el número de ciegos pilóricos varió entre 13 y 23 pudiendo ser monotubulares y ramificados. El intestino, con tres asas, se extiende desde el esfínter pilórico hasta el ano. Histológicamente el tubo digestivo está formado por cuatro capas: mucosa, submucosa, muscular y serosa; el epitelio de revestimiento del esófago es estratificado plano no queratinizado con células caliciformes, cambiando a simple cilíndrico mucosecretor llegando al estómago; en el estómago se encuentra epitelio simple cilíndrico mucosecretor y los ciegos pilóricos e intestino son revestidos por epitelio simple cilíndrico con células caliciformes. Tanto el valor promedio del coeficiente intestinal (0,58, como la pared distensible del estómago sugieren que el Rubio tiene un tubo digestivo propio de carnívoro y sus características histológicas presentan similitud con la mayoría de vertebrados superiores.

  13. Fitness consequences for copepods feeding on a red tide dinoflagellate: deciphering the effects of nutritional value, toxicity, and feeding behavior.

    Science.gov (United States)

    Prince, Emily K; Lettieri, Liliana; McCurdy, Katherine J; Kubanek, Julia

    2006-03-01

    Phytoplankton exhibit a diversity of morphologies, nutritional values, and potential chemical defenses that could affect the feeding and fitness of zooplankton consumers. However, how phytoplankton traits shape plant-herbivore interactions in the marine plankton is not as well understood as for terrestrial or marine macrophytes and their grazers. The occurrence of blooms of marine dinoflagellates such as Karenia brevis suggests that, for uncertain reasons, grazers are unable to capitalize on, or control, this phytoplankton growth-making these systems appealing for testing mechanisms of grazing deterrence. Using the sympatric copepod Acartia tonsa, we conducted a mixed diet feeding experiment to test whether K. brevis is beneficial, toxic, nutritionally inadequate, or behaviorally rejected as food relative to the palatable and nutritionally adequate phytoplankter Rhodomonas lens. On diets rich in K. brevis, copepods experienced decreased survivorship and decreased egg production per female, but the percentage of eggs that hatched was unaffected. Although copepods showed a 6-17% preference for R. lens over K. brevis on some mixed diets, overall high ingestion rates eliminated the possibility that reduced copepod fitness was caused by copepods avoiding K. brevis, leaving nutritional inadequacy and toxicity as remaining hypotheses. Because egg production was dependent on the amount of R. lens consumed regardless of the amount of K. brevis eaten, there was no evidence that fitness costs were caused by K. brevis toxicity. Copepods limited to K. brevis ate 480% as much as those fed only R. lens, suggesting that copepods attempted to compensate for low food quality with increased quantity ingested. Our results indicate that K. brevis is a poor food for A. tonsa, probably due to nutritional inadequacy rather than toxicity, which could affect bloom dynamics in the Gulf of Mexico where these species co-occur.

  14. Dicty_cDB: Contig-U11311-1 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available DNA-directed RNA polymerase II subunit rp... 127 8e-36 EF689770_1( EF689770 |pid:none) Placocarpus schaereri...38977 |pid:none) Eurytemora affinis RNA polymerase ... 120 4e-33 DQ883743_1( DQ883743 |pid:none) Coccoca

  15. Interactions of Copepods with Fractal-Grid Generated Turbulence based on Tomo-PIV and 3D-PTV

    Science.gov (United States)

    Sun, Zhengzhong; Krizan, Daniel; Longmire, Ellen

    2014-11-01

    A copepod escapes from predation by sensing fluid motion caused by the predator. It is thought that the escape reaction is elicited by a threshold value of the maximum principal strain rate (MPSR) in the flow. The present experimental work attempts to investigate and quantify the MPSR threshold value. In the experiment, copepods interact with turbulence generated by a fractal grid in a recirculating channel. The turbulent flow is measured by time-resolved Tomo-PIV, while the copepod motion is tracked simultaneously through 3D-PTV. Escape reactions are detected based on copepod trajectories and velocity vectors, while the surrounding hydrodynamic information is retrieved from the corresponding location in the 3D instantaneous flow field. Measurements are performed at three locations downstream of the fractal grid, such that various turbulence levels can be achieved. Preliminary results show that the number of escape reactions decreases at locations with reduced turbulence levels, where shorter jump distances and smaller change of swimming orientation are exhibited. Detailed quantitative results of MPSR threshold values and the dynamics of copepod escape will be presented. Supported by NSF-IDBR Grant #0852875.

  16. Seasonal dynamics of the copepod community in a tropical monsoonal estuary and the role of sex ratio in their abundance pattern

    Digital Repository Service at National Institute of Oceanography (India)

    Vineetha, G.; Madhu, N.V.; Kusum, K.K.; Sooria, P.M.

    that the dominant copepods had a lower sex ratio during the period of higher abundance, and a negative relation was observed between the abundance and the sex ratio of copepod species during most of the seasons.The preponderance of the mesohaline and euryhaline...

  17. Outdoor rearing facilities of free spawning calanoid copepods for turbot larva can host a bank of resting eggs in the sediment

    DEFF Research Database (Denmark)

    Hansen, Benni Winding; Blanda, Elisa; Drillet, Guillaume;

    2016-01-01

    match the larval needs. When turbot larvae reach metamorphosis and are transferred indoor for weaning, the outdoor tank sediments may reveal vast amounts of copepod eggs undergoing dormancy. Here, we report a copepod species succession firstly among Centropages hamatus and then Acartia spp. both...

  18. Corallovexiidae, a new family of transformed copepods endoparasitic in reef corals with two new genera and ten new species from Curaçao

    NARCIS (Netherlands)

    Stock, Jan H.

    1975-01-01

    Quite a few endoparasitic copepods are known from Indo-Pacific stony corals, but not a single species has so far been recorded from the West Indies. Intensive search in the past few decades has even supported the prevailing opinion that West Indian stony corals are devoid of endoparasitic copepods,

  19. Molecular evidence for the predation of Critically Endangered endemic Aphanius transgrediens from the stomach contents of world wide invasive Gambusia affinis.

    Science.gov (United States)

    Keskin, Emre

    2016-01-01

    Predation and competition among native and invasive species are difficult to study in aquatic environments. Identification of preys from semi-digested body parts sampled from stomach contents of the predator is very challenging. Recent studies were mainly based on use of DNA extracted from stomach content to identify the prey species. This study presents the molecular evidence that reveals the predation of critically endangered Aphanius transgrediens by world-wide invasive Gambusia affinis for a better understanding of the link between the invasion and the extinction of native species in freshwater ecosystems. DNA samples were extracted from semi-digested stomach contents of the invader and short fragments of mitochondrial NADH1 gene were amplified using species-specific primers designed in this study to make identification at species level. Existence of both the prey and the predator species were also confirmed using environmental DNA extracted from water samples.

  20. Cross-reactivities of mammalian MAPKs antibodies in rotifer and copepod: Application in mechanistic studies in aquatic ecotoxicology.

    Science.gov (United States)

    Kang, Hye-Min; Jeong, Chang-Bum; Lee, Young Hwan; Cui, Yan-Hong; Kim, Duck-Hyun; Lee, Min-Chul; Kim, Hui-Su; Han, Jeonghoon; Hwang, Dae-Sik; Lee, Su-Jae; Lee, Jae-Seong

    2016-12-21

    The mitogen-activated protein kinases (MAPKs) family is known to mediate various biological processes in response to diverse environmental pollutants. Although MAPKs are well characterized and studied in vertebrates, in invertebrates the cross-reactivities of MAPKs antibodies were not clearly known in response to environmental pollutants due to limited information of antibody epitopes with material resources for invertebrates. In this paper, we performed phylogenetic analysis of MAPKs genes in the marine rotifer Brachionus koreanus and the copepods Paracyclopina nana and Tigriopus japonicus. Also in rotifer and copepods, several studies of Western blot of MAPK signaling pathways were shown in response to environmental pollutants, including multi-walled carbon nanotubes (MWCNTs), water-accommodated fractions (WAFs) of crude oil, and microplastics. This paper will provide a better understanding of the underlying mechanistic scenario in terms of cross-reactivities of mammalian antibodies in rotifer and copepod. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. Non-limiting food conditions for growth and production of the copepod community in a highly productive upwelling zone

    Science.gov (United States)

    Escribano, Rubén; Bustos-Ríos, Evelyn; Hidalgo, Pamela; Morales, Carmen E.

    2016-09-01

    Zooplankton production is critical for understanding marine ecosystem dynamics. This work estimates copepod growth and production in the coastal upwelling and coastal transition zones off central-southern Chile (~35 to 37°S) during a 3-year time series (2004, 2005, and 2006) at a fixed shelf station, and from spring-summer spatial surveys during the same period. To estimate copepod production (CP), we used species-biomasses and associated C-specific growth rates from temperature dependent equations (food-saturated) for the dominant species, which we assumed were maximal growth rates (gmax). Using chlorophyll-a concentrations as a proxy for food conditions, we determined a size-dependent half-saturation constant with the Michaelis-Menten equation to derive growth rates (g) under the effect of food limitation. These food-dependent C-specific growth rates were much lower (absence of bottom-up control, allowing copepods to grow without limitation due to food resources.

  2. Linking foraging strategies of marine calanoid copepods to patterns of nitrogen stable isotope signatures in a mesocosm study

    DEFF Research Database (Denmark)

    Sommer, Frank; Saage, A.; Santer, B.

    2005-01-01

    foraging mode and, further, with its nitrogen stable isotope signature (delta(15)N). This is because a more carnivorous diet may be expected to result in a higher delta(15)N. We tested this hypothesis in a mesocosm study using a density gradient (0 to 80 ind. 1(-1)) of calanoid copepods. We expected......, whereas nanoflagellates increased with increasing copepod density. As expected, Centropages hamatus, a cruising species, showed the strongest isotopic increase and also highest population growth at low copepod density, suggesting that it was the most efficient species in capturing ciliates. Temora...... longicornis, a stationary suspension-feeder, showed a uniform isotopic increase in all mesocosms, which we believe resulted from nutritional stress arising from poor feeding on both ciliates (too fast for ingestion by T. longicornis) and nanoflagellates (too small). However, Pseudocalanus elongatus, a species...

  3. Changes in Behavior and Brain Acetylcholinesterase Activity in Mosquito Fish, Gambusia affinis in Response to the Sub-Lethal Exposure to Chlorpyrifos

    Directory of Open Access Journals (Sweden)

    R. Nageswara Rao

    2005-12-01

    Full Text Available Sub-lethal studies of chlorpyrifos, O,O-diethyl-O-(3,5,6-trichloro-2-pyridyl phosphorothioate on mosquito fish, Gambusia affinis were carried out in vivo, for 20 days to assess the locomotor behavior in relation to bioaccumulation and interaction with a targeted enzyme, acetylcholinesterase (AChE, EC: 3.1.1.7. Fish exposed to sub-lethal concentration of 60 Ag/L (1/5 of LC50 were under stress, and reduced their locomotor behavior like distance travelled per unit time (m/min and swimming speed (cm/sec with respect to the length of exposure. The alteration in locomotor behavior of fish may be due to an accumulation of acetylcholine (ACh, a neurotransmitter at synaptic junctions, due to the inhibition of AChE enzyme activity (40 to 55% in brain and also bioaccumulation of the toxicant in different parts of fish. The bioaccumulation values indicated that the accumulation of chlorpyrifos was maximum in viscera followed by head and body. The average bioconcentration values are 0.109, 0.009 and 0.004 Ag/g for viscera, head and body with depuration rates of 2.24, 1.69 and 0.39 ng/h respectively. It is evident from the results that the sub-lethal concentration [1/5 of LC50; equivalent to Lowest Observed Effect Concentration (LOEC] of chlorpyrifos can able to alter the locomotor behavior of G. affinis in relation to the length of exposure. The findings revealed that the locomotor activity of test organism could be considered as a suitable marker to evaluate the affect of toxicant even at LOEC levels.

  4. Seasonal change in body length of important small copepods and relationship with environmental factors in Jiaozhou Bay,China

    Institute of Scientific and Technical Information of China (English)

    SUN Xiaohong; SUN Song; LI Chaolun; WANG Minxiao

    2012-01-01

    Differences among species in prosome length and in species' response to environmental factors do exist.Therefore,it is useful to examine prosome length for different copepod species in variable environments.Seasonal variations in prosome length of four small copepods and their copepodite stages in the Jiaozhou Bay were compared and the relative influence of temperature,salinity,and chlorophyll concentration were examined.Two peaks were found in the mean prosome length of Paracalanusparvus (in early winter and May).For Acartia bifilosa,the maximum values of all copepodites occurred mainly from February to April,and decreased to the bottom in July.Prosome length of Acartia pacifica peaked when it first appeared in June,then reached to the minimum in July.Parvocalanus crassirostris only appeared from late summer to autumn and the mean prosome length showed no clear changes.Correlations of adult prosome length with environmental factors were evaluated.For the four species,temperature was negatively correlated to prosome length except for P.crassirostris.But the different species varied markedly in their responds to temperature.A.bifilosa showed a more definite trend of size variation with temperature than P.parvus and A.pacifica.Correlations of prosome length with salinity were significantly positive for almost all the small copepods.The relationship between chlorophyll concentration and prosome length was complicated for these copepods,but for P.parvus,chlorophyll concentration was also an important affecting factor.Furthermore,investigation needs to be done on food quality for some copepod.These results are essential to estimate the biomass and the production,and to understand these small copepods' population dynamics in this human-affected bay.

  5. Exploring copepod distribution patterns at three nested spatial scales in a spring system: habitat partitioning and potential for hydrological bioindication

    Directory of Open Access Journals (Sweden)

    Fabio Stoch

    2015-06-01

    Full Text Available In groundwater-fed springs, habitat characteristics are primarily determined by a complex combination of geomorphic features and physico-chemical parameters, while species assemblages are even more intricate. Springs host species either inhabiting the spring mouth, or colonizing spring habitats from the surface or from the aquifers which feed the springs. Groundwater species living in springs have been claimed as good candidates for identifying dual aquifer flowpaths or changes in groundwater pathways before reaching the spring outlets. However, the reliability of spring species as hydrological biotracers has not been widely investigated so far. Our study was aimed at analysing a large karstic spring system at three nested spatial scales in order: i to assess, at whole spring system scale, the presence of a groundwater divide separating two aquifers feeding two spring units within a single spring system, by combining isotope analyses, physico-chemistry, and copepod distribution patterns; ii to test, at vertical spring system scale, the effectiveness of copepods in discriminating surface and subsurface habitat patches within the complex mosaic spring environment; iii to explore, at local spring unit level, the relative role of hydrochemistry and sediment texture as describers of copepod distribution among microhabitats. The results obtained demonstrated the presence of a hierarchical spatial structure, interestingly reflected in significant differences in assemblage compositions. Copepod assemblages differed between the two contiguous spring units, which were clearly characterized by their hydrochemistry and by significant differences in the groundwater flowpaths and recharge areas, as derived by the isotope analyses. The biological results suggested that stygobiotic species seem to be related to the origin of groundwater, suggesting their potential role as hydrological biotracers. At vertical scale, assemblage composition in surface and

  6. Temperature Affects the Use of Storage Fatty Acids as Energy Source in a Benthic Copepod (Platychelipus littoralis, Harpacticoida).

    Science.gov (United States)

    Werbrouck, Eva; Van Gansbeke, Dirk; Vanreusel, Ann; De Troch, Marleen

    2016-01-01

    The utilization of storage lipids and their associated fatty acids (FA) is an important means for organisms to cope with periods of food shortage, however, little is known about the dynamics and FA mobilization in benthic copepods (order Harpacticoida). Furthermore, lipid depletion and FA mobilization may depend on the ambient temperature. Therefore, we subjected the temperate copepod Platychelipus littoralis to several intervals (3, 6 and 14 days) of food deprivation, under two temperatures in the range of the normal habitat temperature (4, 15 °C) and under an elevated temperature (24 °C), and studied the changes in FA composition of storage and membrane lipids. Although bulk depletion of storage FA occurred after a few days of food deprivation under 4 °C and 15 °C, copepod survival remained high during the experiment, suggesting the catabolization of other energy sources. Ambient temperature affected both the degree of FA depletion and the FA mobilization. In particular, storage FA were more exhausted and FA mobilization was more selective under 15 °C compared with 4 °C. In contrast, depletion of storage FA was limited under an elevated temperature, potentially due to a switch to partial anaerobiosis. Food deprivation induced selective DHA retention in the copepod's membrane, under all temperatures. However, prolonged exposure to heat and nutritional stress eventually depleted DHA in the membranes, and potentially induced high copepod mortality. Storage lipids clearly played an important role in the short-term response of the copepod P. littoralis to food deprivation. However, under elevated temperature, the use of storage FA as an energy source is compromised.

  7. Annual egg production rates of calanoid copepod species on the continental shelf of the Eastern Tropical Pacific off Mexico

    Science.gov (United States)

    Kozak, Eva R.; Franco-Gordo, Carmen; Palomares-García, Ricardo; Gómez-Gutiérrez, Jaime; Suárez-Morales, Eduardo

    2017-01-01

    We provide the first estimations of calanoid copepod egg production rates (EPR) in the Eastern Tropical Pacific over an annual cycle (January-December 2011). Gravid females were collected twice monthly and incubated for 12 h without food to estimate EPR, weight-specific fecundity (Gf), spawning success (SS, percentage of females to spawn out of the total species incubated per month and season) and egg hatching success (EHS). This study reports the average EPR of 10 species and the monthly EPR and Gf of four planktonic calanoid copepods (Centropages furcatus, Temora discaudata, Pontellina sobrina, and Nannocalanus minor) that spawned with enough frequency to infer their seasonal reproductive patterns. These species showed distinct seasonal reproductive strategies. Most copepod species spawned sporadically with large EPR variability, while three copepod species reproduced throughout the year (C. furcatus, T. discaudata and P. sobrina) and N. minor spawned only during the mixed period (Feb-May). The four species had relatively similar average EPR (C. furcatus 16, T. discaudata 18, P. sobrina 13, and N. minor 12 eggs fem-1 day-1). These are the first EPR estimations of P. sobrina and its previously known reproductive period is expanded. A Canonical Correspondence Analysis (CCA) was used to analyze EPR and species abundance of all calanoid copepods (40 spp.) collected throughout the time series in relation to temperature, salinity, mixed layer depth (MLD), dissolved oxygen, and chlorophyll a (Chl-a) concentrations to identify the variables that best explained the copepod abundance variability. Temperature, Chl-a, and salinity had the strongest effect on the biological variables, linked to seasonal and episodic upwelling-downwelling processes in the surveyed area. As a result of moderate upwelling events and seasonal variation of environmental conditions, it appears relatively few species are capable of maintaining continuous reproduction under the relatively higher

  8. Seasonality of parasitic copepods on bullseye puffer, Sphoeroides annulatus (Pisces: Tetraodontidae), from the northwestern coast of Mexico.

    Science.gov (United States)

    Morales-Serna, Francisco Neptalí; Rubio-Godoy, Miguel; Gómez, Samuel

    2011-08-01

    Seasonal occurrence of parasitic copepods in wild bullseye puffer, Sphoeroides annulatus (Pisces: Tetraodontidae), was analyzed in conjunction with variation of biotic and abiotic factors. Eleven samples were taken between February 2007 and February 2008 in Santa María La Reforma lagoon (northwestern coast of México). In total, 337 fish was examined; 5 parasitic copepod species were observed, including Acantholochus zairae , Caligus serratus , Lepeophtheirus simplex , Pseudochondracanthus diceraus , and Parabrachiella sp. The most common species were L. simplex , P. diceraus, and C. serratus (overall prevalence, 59, 53, and 35%, respectively), which significantly varied in prevalence and mean intensity between sampling months. A seasonal pattern was only observed for L. simplex, with higher infection levels in the warmest month than in the coldest month. Statistical analyses indicated that the intensity of L. simplex was positively correlated with water temperature. There were no significant differences in prevalence and intensity of infection among female and male hosts. At the component community level, species richness ranged between 4 and 5 during most of the study period, and no seasonality was observed in the number of individuals, Shannon diversity index, evenness index, or the Berger-Parker dominance index. At the infracommunity level, 4 descriptors used (mean species richness, mean number of individuals, mean Brillouin's diversity index, and mean Berger-Parker index) varied significantly between sampling months, but no seasonality was observed, except for a slight increase in the number of individuals during the warmest month. A significant positive association was detected between number of individuals and water temperature and between host size and both species richness and number of individuals. This is the first account of the ecology of these 5 parasitic copepods. Although no significant association was detected between fish condition factor and the

  9. Astaxanthin, canthaxanthin and astaxanthin esters in the copepod Acartia bifilosa (Copepoda, Calanoida during ontogenetic development

    Directory of Open Access Journals (Sweden)

    Maria £otocka

    2001-12-01

    Full Text Available The contents of astaxanthin, canthaxanthin and astaxanthin esters were studied in natural populations of the copepod Acartia bifilosa from the Pomeranian Bay and Gulf of Gdansk in the southern Baltic Sea. Samples dominated by any one of three developmental groups: (1 nauplii, (2 copepodids I-III and (3 copepodids IV-V and adults of Acartia bifilosa were analysed by means of high performance liquid chromatography (HPLC. As ontogenetic development progressed, significant changes occurred in the proportion of particular pigments in the total pigment pool of the various developmental groups. Astaxanthin and canthaxanthin occurred in all the groups, the former being clearly dominant. However, an increasing percentage of astaxanthin esters was recorded in the copepodids I-III, and even more in the copepodids IV-V and adults group. Most probably, astaxanthin is the main pigment active in copepod lipid metabolism. Carotenoid pigments in copepods very likely act as efficient free-electron quenchers and may be involved as antioxidants in rapid lipid metabolism. The exogenously feeding stages (late nauplii and copepodids transform plant carotenoids taken from food and are evidently capable of metabolising astaxanthin by esterification and further degradation. It is emphasised that, according to literature data, astaxanthin esters may have an even higher quenching ability. It is suggested that crustacean carotenoid pigments, with their electron donor-acceptor abilities, may replace oxygen in peroxidation processes connected with lipid metabolism. The consequences of such a physiological role of astaxanthin for present-day estimations of energy balances in zooplankton communities are mentioned.

  10. Early ice retreat and ocean warming may induce copepod biogeographic boundary shifts in the Arctic Ocean

    Science.gov (United States)

    Feng, Zhixuan; Ji, Rubao; Campbell, Robert G.; Ashjian, Carin J.; Zhang, Jinlun

    2016-08-01

    Early ice retreat and ocean warming are changing various facets of the Arctic marine ecosystem, including the biogeographic distribution of marine organisms. Here an endemic copepod species, Calanus glacialis, was used as a model organism, to understand how and why Arctic marine environmental changes may induce biogeographic boundary shifts. A copepod individual-based model was coupled to an ice-ocean-ecosystem model to simulate temperature- and food-dependent copepod life history development. Numerical experiments were conducted for two contrasting years: a relatively cold and normal sea ice year (2001) and a well-known warm year with early ice retreat (2007). Model results agreed with commonly known biogeographic distributions of C. glacialis, which is a shelf/slope species and cannot colonize the vast majority of the central Arctic basins. Individuals along the northern boundaries of this species' distribution were most susceptible to reproduction timing and early food availability (released sea ice algae). In the Beaufort, Chukchi, East Siberian, and Laptev Seas where severe ocean warming and loss of sea ice occurred in summer 2007, relatively early ice retreat, elevated ocean temperature (about 1-2°C higher than 2001), increased phytoplankton food, and prolonged growth season created favorable conditions for C. glacialis development and caused a remarkable poleward expansion of its distribution. From a pan-Arctic perspective, despite the great heterogeneity in the temperature and food regimes, common biogeographic zones were identified from model simulations, thus allowing a better characterization of habitats and prediction of potential future biogeographic boundary shifts.

  11. Use of flubendazole as a therapeutic agent against rotifers (Brachionus plicatilis) in intensive cultures of the harpacticoid copepod Tisbe holothuriae

    DEFF Research Database (Denmark)

    Steenfeldt, Svend Jørgen; Nielsen, Johan W.

    2010-01-01

    holothuria). Flubendazole was lethal to rotifers in concentrations as low as 0.05 mg L−1. There was no significant effect on the concentration of copepods, even at the highest concentration tested, i.e. 5.0 mg L−1 flubendazole. We conclude that flubendazole is an effective drug for control of B. plicatilis...... down production and subsequently use a therapeutic agent to eliminate all zooplankton in the system before restart with a stock culture free of rotifers. We tested flubendazole as a mean of controlling rotifers (Brachionus plicatilis) in intensive laboratory cultures of the harpacticoid copepod (Tisbe...

  12. Changes in free amino acid content during naupliar development of the Calanoid copepod Acartia tonsa

    DEFF Research Database (Denmark)

    Rayner, Thomas Allan; Jørgensen, Niels O. G.; Drillet, Guillaume

    2017-01-01

    Changes in free amino acids (FAA) were investigated in the potentially important live feed and neritic copepod species Acartia tonsa during naupliar development. Total content of FAA in A. tonsa nauplii was around 17% of dry weight at first development stage, and declined to 6% for later stages....... Relative to body-volume and biomass, the FAA content indicated possible volume-dependent changes. However, changes in FAA with osmolytic activity could not account for this decline in FAA content, but suggests that the decline reflected degradation of residual FAAs from the embryonic stage. Glutamic acid...

  13. Inhibition of larval development of the marine copepod Acartia tonsa by four synthetic musk substances

    DEFF Research Database (Denmark)

    Wollenberger, Leah; Breitholtz, M.; Kusk, Kresten Ole

    2003-01-01

    ketone) and 2.5 mg/l (Tonalide(TM)). Since, the synthetic musks strongly inhibited larval development in A. tonsa at low nominal concentrations, they should be considered as very toxic. The larval development test with A. tonsa is able to provide important aquatic toxicity data for the evaluation...... of synthetic musks, for which there is little published ecotoxicological information available regarding Crustacea. It is suggested that subchronic and chronic copepod toxicity tests should be used more frequently for risk assessment of environmental pollutants. (C) 2002 Elsevier Science B.V. All rights...

  14. Potential of the small cyclopoid copepod Paracyclopina nana as an invertebrate model for ecotoxicity testing.

    Science.gov (United States)

    Dahms, Hans-Uwe; Won, Eun-Ji; Kim, Hui-Su; Han, Jeonghoon; Park, Heum Gi; Souissi, Sami; Raisuddin, Sheikh; Lee, Jae-Seong

    2016-11-01

    Aquatic invertebrates contribute significantly to environmental impact assessment of contaminants in aquatic ecosystems. Much effort has been made to identify viable and ecologically relevant invertebrate test organisms to meet rigorous regulatory requirements. Copepods, which are ecologically important and widely distributed in aquatic organisms, offer a huge opportunity as test organisms for aquatic toxicity testing. They have a major role not only in the transfer of energy in aquatic food chains, but also as a medium of transfer of aquatic pollutants across the tropic levels. In this regard, a supratidal and benthic harpacticoid copepod Tigriopus japonicus Mori (order Harpacticoida) has shown promising characteristics as a test organism in the field of ecotoxicology. Because there is a need to standardize a battery of test organisms from species in different phylogenetic and critical ecosystem positions, it is important to identify another unrelated planktonic species for wider application and comparison. In this regard, the cyclopoid copepod Paracyclopina nana Smirnov (order Cyclopoida) has emerged as a potential test organism to meet such requirements. Like T. japonicus, it has a number of features that make it a candidate worth consideration in such efforts. Recently, the genomics of P. nana has been unraveled. Data on biochemical and molecular responses of P. nana against exposure to environmental chemicals and other stressors have been collected. Recently, sequences and expression profiles of a number of genes in P. nana encoding for heat shock proteins, xenobiotic-metabolizing enzymes, and antioxidants have been reported. These genes serve as potential biomarkers in biomonitoring of environmental pollutants. Moreover, the application of gene expression techniques and the use of its whole transcriptome have allowed evaluation of transcriptional changes in P. nana with the ultimate aim of understanding the mechanisms of action of environmental stressors

  15. Acute toxicity testing with the tropical marine copepod Acartia sinjiensis: optimisation and application.

    Science.gov (United States)

    Gissi, F; Binet, M T; Adams, M S

    2013-11-01

    Globally there is limited toxicity data for tropical marine species, and there has been a call for further research and development in the area of tropical marine ecotoxicology. An increase in developmental pressures in northern tropical Australia is causing a higher demand for toxicity test protocols with ecologically relevant species. Copepods are a diverse group of zooplankton that are major components of marine food webs. The calanoid copepod Acartia sinjiensis is widely distributed across tropical and sub-tropical brackish to marine waters of Australia and was identified in a recent comprehensive review of marine tropical toxicity testing in Australia as a suitable test organism. Through a number of optimisation steps including feeding trials, changes to culture and test conditions; a 48-h acute toxicity test with A. sinjiensis was modified to become a highly reliable and reproducible standard test protocol. Control mobility was improved significantly, and the sensitivity of A. sinjiensis to copper (EC50 of 33µg/L), ammonia (EC50 of 10mg/L) and phenol (EC50 of 13mg/L) fell within the ranges of those reported previously, indicating that the modifications did not alter its sensitivity. In a comprehensive literature search we found that this species was the most sensitive to copper out of a range of marine copepods. The test was also successfully applied in toxicity assessments of four environmental samples: two produced formations waters (PFWs) and two mine tailing liquors (MTLs). The toxicity assessments utilised toxicity data from a suite of marine organisms (bacteria, microalgae, copepods, sea urchins, oysters, prawns, and fish). For the PFWs, which were predominantly contaminated with organic chemicals, A. sinjiensis was the most sensitive species (EC50 value 2-17 times lower than for any other test species). For the predominantly metal-contaminated mine tailing liquors, its sensitivity was similar to that of other test species used. The modified 48-h acute

  16. [Lernaeenicus vorax Richiardi, 1877. Parasitic copepod of Sciaenides from the Gulf of Tunis (Tunisia)].

    Science.gov (United States)

    Ktari, M H; Chakroun, N

    1981-01-01

    The study of the Tunis bay Sciaenidae has made it possible to point out the presence of a parasite Copepod Lernaeenicus vorax Richiardi, 1877 with a more important parasitism in argyrosomus regius (11.5 %) and Umbrina cirrosa (9.2 %) in Sciaena umbra (0.6 %). The parasites, chiefly one per host, get fixed on the right side or on the left one preferably at the level of the fish's fins. Among Umbrina cirrosa the juveniles ones have proved to be more parasitic (82,13 %) than the adults one (17,85 %).

  17. Dealing with the presence of the ciliate Euplotes sp. in cultures of the copepod Acartia tonsa

    DEFF Research Database (Denmark)

    Drillet, Guillaume; Dutz, Jörg

    2014-01-01

    Ciliates in live feed cultures can be a pest that lower production yields. This could dramatically affect the management and success of copepod cultures. In this study, we investigated the effect of the ciliate Euplotes sp. on egg production, specific egg production and egg hatching success...... of Acartia tonsa fed with Rhodomonas salina. We found that at a concentration of 2 cells ml-1, Euplotes sp. had no effect on the production and hatching success of eggs but increased/decreased the mortality/quality of non-subitaneous eggs. Euplotes sp. had a good fatty acid profile containing high proportion...

  18. Zooplankton, especially calanoid copepods, in the upper 1000m of the south-east Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Madhupratap, M.; Haridas, P.

    species in Figures 3-6), abundances were averaged for day and night for further processing of data. Associations between calanoid copepod species were determined by group-average sorting using the Bray-Curtis measure after standardization... 199 o • 0 • 0 • 193 197 INDIA Hg. 1. Station positions. Open circles, day stations; closed circles, nightstalion.~. Table I. Details of stations where sampling was conducted Station no. 193 4 194 195 0 196 ]97 8 ]99 Position (longitude) 68~03' 69...

  19. Egg production, growth and development of the cyclopoid copepod Oithona similis

    DEFF Research Database (Denmark)

    Sabatini, Marina; Kiørboe, Thomas

    1994-01-01

    Egg production, growth and development rates of Oithona similis were measured in the laboratory as a function of food concentration and composition. On an optimum diet, development is isochronal and growth is near exponential. The maximum juvenile growth rate at 15 degree C (0.2 day-1) is similar...... to juvenile growth in calanoid copepods. The maximum weight-specific egg production rate (0.1 day-1), on the other hand, is substantially less than in free-spawning calanoids, but similar to that in egg-carrying calanoids. In the Kattegat, Oithona spp. egg production is strongly limited by food during summer...

  20. Influence of LAS on marine calanoid copepod population dynamics and potential reproduction.

    Science.gov (United States)

    Christoffersen, Kirsten; Hansen, Benni W; Johansson, Liselotte S; Krog, Elisabeth

    2003-05-29

    The toxicity of linear alkyl benzene sulfonate (LAS) to marine invertebrates is well documented under laboratory conditions using single-species tests. It is less known how LAS affects natural populations of aquatic organisms. We hypothesised that LAS was more toxic to the calanoid copepod Acartia sp. under natural conditions than Acartia tonsa under cultured conditions in the laboratory. This hypothesis was checked by a direct comparison of LAS toxicity in single-species and model (mesocosm) studies. The acute and sublethal effects of LAS on the survival and egg production of laboratory reared A. tonsa were examined by standard test, i.e. incubation with LAS without food for 24-72 h. The LC(50) and EC(50) values averaged 1.23 and 0.74 mg l(-1) for survival and egg production, respectively. These values are comparable to previous reports. The effects of LAS on a natural copepod community were also investigated under in situ conditions. A series of seven mesocosms (holding approx. 3 m(3) of seawater each) was established with two mesocosms being controls without LAS and five mesocosms with increasing concentrations of LAS ranging from 0.1 to 6.5 mg l(-1) applied as a single dose. The indigenous copepod community, dominated by Acartia sp. and Centropages sp., responded clearly to LAS concentrations above 0.1 mg l(-1). The calculated no effect value was 0.14 mg LAS l(-1) (95% CI=0.08-1.82 mg LAS l(-1)) for the entire copepod community including all development stages after 24 h exposure. The increased sensitivity under in situ conditions was probably promoted by the suboptimal growth conditions, e.g. no saturated food concentration or inadequate nutritive values of the food. The amount of food expressed as chlorophyll concentration was low (around 2 microg chl. a l(-1)) but was not affected by LAS. It appeared that the naupliar stages of Acartia and Centropages were the least affected by LAS and that new cohorts were able to develop 15 days after the dosing with LAS.

  1. Feasting in fresh water: impacts of food concentration on freshwater tolerance and the evolution of food × salinity response during the expansion from saline into fresh water habitats.

    Science.gov (United States)

    Lee, Carol Eunmi; Moss, Wynne E; Olson, Nora; Chau, Kevin Fongching; Chang, Yu-Mei; Johnson, Kelsey E

    2013-06-01

    Saline to freshwater invasions have become increasingly common in recent years. A key hypothesis is that rates of freshwater invasions have been amplified in recent years by increased food concentration, yet this hypothesis has remained unexplored. We examined whether elevated food concentration could enhance freshwater tolerance, and whether this effect evolves following saline to freshwater invasions. We examined physiological response to salinity and food concentration in a 2 × 2 factorial design, using ancestral brackish and freshwater invading populations of the copepod Eurytemora affinis. We found that high food concentration significantly increases low-salinity tolerance. This effect was reduced in the freshwater population, indicating evolution following the freshwater invasion. Thus, ample food could enable freshwater invasions, allowing subsequent evolution of low-salinity tolerance even under food-poor conditions. We also compared effects of food concentration on freshwater survival between two brackish populations from the native range. Impacts of food concentration on freshwater survival differed between the brackish populations, suggesting variation in functional properties affecting their propensity to invade freshwater habitats. The key implication is that high food concentration could profoundly extend range expansions of brackishwater species into freshwater habitats, potentially allowing for condition-specific competition between saline invaders and resident freshwater species.

  2. Optimal salinity for dominant copepods in the East China Sea, determined using a yield density model

    Institute of Scientific and Technical Information of China (English)

    XU Zhaoli; GAO Qian

    2011-01-01

    From 1997 to 2000, four field surveys were conducted in the East China Sea (ECS)(23°30′ 33°00′N, 118°30′-128°00′E). A field data yield density model was used to determine the optimal salinities for 19 dominant copepod species to establish the relationship between surface salinities and abundance of those species. In addition, ecological groups of the copepods were classified based on optimal salinity and geographical distribution. The results indicate that the yield density model is suitable for determining the relationship between salinity and abundance. Cosmocalanus darwini, Euchaeta rimana,Pleuromamma gracilis, Rhincalanus cornutus, Scolecithrix danae and Pareucalanus attenuatus were determined as oceanic species, with optimal salinities of >34.0. They were stenohaline and mainly distributed in waters influenced by the Kuroshio or Taiwan warm current. Temoa discaudata, T. stylifera and Canthocalanus pauper were nearshore species with optimal salinities of <33.0 and most abundant in coastal waters. The remaining 10 species, including Undinula vulgaris and Subeucalanus subcrassus, were offshore species, with optimal salinity ranging from 33.0-34.0. They were widely distributed in nearshore,offshore and oceanic waters but mainly in the mixed water of the ECS.

  3. Response of Acartia tonsa to Burgers' Vortex: Deconstructing Turbulence-Copepod Interactions

    Science.gov (United States)

    Young, D. L.; Webster, D. R.; Yen, J.

    2014-11-01

    In situ studies suggest that in many oceanic regimes, turbulence affects the vertical position of copepods primarily by changing their behavior, and only secondarily by altering their physical position. We test the hypothesis that fine-scale turbulence alters copepod behavior, presenting as alterations in directed movement and changes in swimming kinematics. To this end, we create two Burgers' vortices, specifying the rotation rate and axial strain rate to correspond to turbulent vortices with size scale equaling the inverse wavenumber of the median viscous dissipation rate (i.e. r = 8.1 η) for typical turbulent conditions in the coastal or near surface region (i.e., mean turbulent dissipation rates of 0.009 and 0.096 cm2/s3) . The vortex flow is quantified via tomo-PIV. Behavioral assays of Acartia tonsa are conducted, generating 3D trajectories for analysis of swimming kinematics and response to hydrodynamic cues. A. tonsa did not significantly respond to the vortex corresponding to dissipation rate of 0.009 cm2/s3, but drastically altered their swimming behavior in the presence of the 0.096 cm2/s3 vortex, including increased relative swim speed, angle of alignment with the vortex axis, net-to-gross displacement ratio, and escape acceleration, along with decreased turn frequency (relative to stagnant control conditions). Further, A. tonsa escape location is preferentially in the core of the stronger vortex, indicating that the hydrodynamic cue triggering the distinctive escape behavior is vorticity.

  4. Effect of chemically contaminated marine sediment on naupliar production of the marine harpacticoid copepod, Tigriopus californicus

    Energy Technology Data Exchange (ETDEWEB)

    Misitano, D.A.; Schiewe, M.H. (National Oceanic and Atmospheric Administration, Seattle, WA (USA))

    1990-04-01

    There is a growing body of evidence indicating that chemically contaminated sediments in urban bays and estuaries pose a significant threat to the productivity of these important marine habitats. Particularly at risk are benthic species which live in direct contact with the sediment. However, nondemersal species are also at risk via the food chain and by direct contact with resuspended sediment particulates. There are substantial data on the lethal and sublethal effects of aqueous contaminants on a variety of aquatic species. In contrast, there is very limited information on the toxic effects of the generally water-insoluble sediment-associated contaminants. In the present communication the authors report a series of experiments in which the harpacticoid copepod, Tigriopus californicus, was exposed to sediments from urban and nonurban bays, and reproductive success was evaluated. This species was selected for study as it is widely distributed along the West Coast of North America, and as a group, copepods are an important component of the marine food chain. In addition, the relatively short reproductive life span of this species makes it particularly amenable for studies of reproductive success. Here, the authors report reduced and irregular naupliar production as a consequence of exposure to chemically contaminated sediments from urban waterways.

  5. Potential fitness trade-offs for thermal tolerance in the intertidal copepod Tigriopus californicus.

    Science.gov (United States)

    Willett, Christopher S

    2010-09-01

    Thermal adaptation to spatially varying environmental conditions occurs in a wide range of species, but what is less clear is the nature of fitness trade-offs associated with this temperature adaptation. Here, populations of the intertidal copepod Tigriopus californicus are examined at both local and latitudinal scales to determine whether these populations have evolved differences in their survival under high temperature stress. A clear pattern of increasing high temperature stress tolerance is seen with decreasing latitude, consistent with temperature adaptation. Additionally, there is also evidence for significant variation in thermal tolerance on a smaller scale. The competitive fitness of pairs of northern and southern copepod populations were also examined under a series of lower, more moderate temperatures. These fitness assays show that the southern populations that have the best survival under extreme high temperatures have lowered competitive fitness at the lower temperatures tested, whereas the fitness of the southern populations exceeded that of the northern populations at the highest temperatures tested. Combined, these results suggest that there may be evolutionary trade-offs between performance at high and stressful temperatures and fitness at moderate temperatures in this species.

  6. Interpopulational variation in the cold tolerance of a broadly distributed marine copepod.

    Science.gov (United States)

    Wallace, Gemma T; Kim, Tiffany L; Neufeld, Christopher J

    2014-01-01

    Latitudinal trends in cold tolerance have been observed in many terrestrial ectotherms, but few studies have investigated interpopulational variation in the cold physiology of marine invertebrates. Here, the intertidal copepod Tigriopus californicus was used as a model system to study how local adaptation influences the cold tolerance of a broadly distributed marine crustacean. Among five populations spanning 18° in latitude, the following three metrics were used to compare cold tolerance: the temperature of chill-coma onset, the chill-coma recovery time and post-freezing recovery. In comparison to copepods from warmer southern latitudes, animals from northern populations exhibited lower chill-coma onset temperatures, shorter chill-coma recovery times and faster post-freezing recovery rates. Importantly, all three metrics showed a consistent latitudinal trend, suggesting that any single metric could be used equivalently in future studies investigating latitudinal variation in cold tolerance. Our results agree with previous studies showing that populations within a single species can display strong local adaptation to spatially varying climatic conditions. Thus, accounting for local adaptation in bioclimate models will be useful for understanding how broadly distributed species like T. californicus will respond to anthropogenic climate change.

  7. Hybrid breakdown weakens under thermal stress in population crosses of the copepod Tigriopus californicus.

    Science.gov (United States)

    Willett, Christopher S

    2012-01-01

    The outcome of hybridization can be impacted by environmental conditions, which themselves can contribute to reproductive isolation between taxa. In crosses of genetically divergent populations, hybridization can have both negative and positive impacts on fitness, the balance between which might be tipped by changes in the environment. Genetically divergent populations of the intertidal copepod Tigriopus californicus have been shown to differ in thermal tolerance at high temperatures along a latitudinal gradient. In this study, a series of crosses were made between pairs of genetically divergent populations of T. californicus, and the thermal tolerance of these hybrids was tested. In most cases, the first-generation hybrids had relatively high thermal tolerance and the second-generation hybrids were not generally reduced below the less-tolerant parental population for high temperature tolerance. This pattern contrasts with previous studies from crosses of genetically divergent populations of this copepod, which often shows hybrid breakdown in these second-generation hybrids for other measures of fitness. These results suggest that high temperature stress could either increase the positive impacts of hybridization or decrease the negative impacts of hybridization resulting in lowered hybrid breakdown in these population crosses.

  8. Characterization of the glutamate dehydrogenase gene and its regulation in a euryhaline copepod.

    Science.gov (United States)

    Willett, Christopher S; Burton, Ronald S

    2003-08-01

    Glutamate dehydrogenase (GDH) plays a key role in the metabolism of free amino acids (FAA) in crustaceans and other metazoans. Glutamate synthesized by GDH via reductive amination is the amino group donor for alanine synthesis and the precursor required for proline synthesis. Since both proline and alanine are important intracellular osmolytes in many marine invertebrates, GDH has been widely implicated as playing a central role in response to hyperosmotic stress in these organisms. We have isolated the gene encoding a GDH homolog from the euryhaline copepod Tigriopus californicus and examined the regulation of GDH under salinity stress. The gene encodes a protein of 557 residues with 76% amino acid identity with Drosophila melanogaster GDH. The gene encodes an N-terminal mitochondrial signal sequence peptide. Only a single intron of 71 bp was found in the GDH gene in T. californicus when genomic sequences and cDNA sequences were compared. The levels of GDH mRNA do not increase during hyperosmotic stress in this copepod. The effects of salt and hyperosmotic stress on GDH enzyme activity were also investigated. GDH activities decrease with increasing NaCl concentrations in in vitro enzyme assays, while live animals exposed to hyperosmotic stress showed no change in GDH enzyme activities. Combined, these results indicate that GDH transcription and enzyme activity do not appear to function in the regulation of alanine and proline accumulation during hyperosmotic stress in T. californicus. The manner in which this important physiological process is regulated remains unknown.

  9. The nature of interactions that contribute to postzygotic reproductive isolation in hybrid copepods.

    Science.gov (United States)

    Willett, Christopher S

    2011-05-01

    Deleterious interactions within the genome of hybrids can lower fitness and result in postzygotic reproductive isolation. Understanding the genetic basis of these deleterious interactions, known as Dobzhansky-Muller incompatibilities, is the subject of intense current study that seeks to elucidate the nature of these deleterious interactions. Hybrids from crosses of individuals from genetically divergent populations of the intertidal copepod Tigriopus californicus provide a useful model in which to study Dobzhansky-Muller incompatibilities. Studies of the basis of postzygotic reproductive isolation in this species have revealed a number of patterns. First, there is evidence for a breakdown in genomic coadaptation between mtDNA-encoded and nuclear-encoded proteins that can result in a reduction in hybrid fitness in some crosses. It appears from studies of the individual genes involved in these interactions that although this coadaptation could lead to asymmetries between crosses, patterns of genotypic viabilities are not often consistent with simple models of genomic coadaptation. Second, there is a large impact of environmental factors on these deleterious interactions suggesting that they are not strictly intrinsic in nature. Temperature in particular appears to play an important role in determining the nature of these interactions. Finally, deleterious interactions in these hybrid copepods appear to be complex in terms of the number of genetic factors that interact to lead to reductions in hybrid fitness. This complexity may stem from three or more factors that all interact to cause a single incompatibility or the same factor interacting with multiple other factors independently leading to multiple incompatibilities.

  10. Optimal salinity for dominant copepods in the East China Sea, determined using a yield density model

    Science.gov (United States)

    Xu, Zhaoli; Gao, Qian

    2011-05-01

    From 1997 to 2000, four field surveys were conducted in the East China Sea (ECS) (23°30'-33°00'N, 118°30'-128°00'E). A field data yield density model was used to determine the optimal salinities for 19 dominant copepod species to establish the relationship between surface salinities and abundance of those species. In addition, ecological groups of the copepods were classified based on optimal salinity and geographical distribution. The results indicate that the yield density model is suitable for determining the relationship between salinity and abundance. Cosmocalanus darwini, Euchaeta rimana, Pleuromamma gracilis, Rhincalanus cornutus, Scolecithrix danae and Pareucalanus attenuatus were determined as oceanic species, with optimal salinities of >34.0. They were stenohaline and mainly distributed in waters influenced by the Kuroshio or Taiwan warm current. Temora discaudata, T. stylifera and Canthocalanus pauper were nearshore species with optimal salinities of <33.0 and most abundant in coastal waters. The remaining 10 species, including Undinula vulgaris and Subeucalanus subcrassus, were offshore species, with optimal salinity ranging from 33.0-34.0. They were widely distributed in nearshore, offshore and oceanic waters but mainly in the mixed water of the ECS.

  11. Feeding behavior of large calanoid copepods Neocalanus cristatus and N. plumchrus from the subarctic Pacific Ocean

    Science.gov (United States)

    Frost, B. W.; Landry, M. R.; Hassett, R. P.

    1983-01-01

    Oceanic waters of the subarctic Pacific exhibit a special ecological feature, a virtually seasonally invariant standing stock of phytoplankton (measured as chlorophyll a), that seems to reflect a balance, at least during spring and summer, between phytoplankton growth and zooplankton grazing. The grazers presumed to be responsible for the balance are the calanoid copepods Neocalanus cristatus and N. plumchrus. Shipboard grazing experiments, utilizing both natural suspended particulate material and cultured phytoplankton as food for the copepods, showed that both species have at least three attributes of feeding behavior required to maintain steady standing stock of phytoplankton. That is, the Neocalanus species can feed at the low concentrations of phytoplankton that prevail in the open subarctic Pacific, they feed at similar rates on a broad range of particlessizes including the predominant particles, and they respond to small increases in phytoplankton concentration by proportionately larger increases in their feeding rate. Although both species of Neocalanus attain larger body sizes than co-occurring Calanus pacificus and Pseudocalanus sp., they have morphological specializations that seem to account for their unexpected ability to feed on very dilute suspensions of small phytoplankton cells. It appears that the perpetually low phytoplankton concentrations in the open subarctic Pacific do not permit maximum feeding effort by the species of Neocalanus.

  12. Biogeographic responses of the copepod Calanus glacialis to a changing Arctic marine environment.

    Science.gov (United States)

    Feng, Zhixuan; Ji, Rubao; Ashjian, Carin; Campbell, Robert; Zhang, Jinlun

    2017-09-04

    Dramatic changes have occurred in the Arctic Ocean over the past few decades, especially in terms of sea ice loss and ocean warming. Those environmental changes may modify the planktonic ecosystem with changes from lower to upper trophic levels. This study aimed to understand how the biogeographic distribution of a crucial endemic copepod species, Calanus glacialis, may respond to both abiotic (ocean temperature) and biotic (phytoplankton prey) drivers. A copepod individual-based model coupled to an ice-ocean-biogeochemical model was utilized to simulate temperature- and food-dependent life cycle development of C. glacialis annually from 1980 to 2014. Over the 35-year study period, the northern boundaries of modeled diapausing C. glacialis expanded poleward and the annual success rates of C. glacialis individuals attaining diapause in a circumpolar transition zone increased substantially. Those patterns could be explained by a lengthening growth season (during which time food is ample) and shortening critical development time (the period from the first feeding stage N3 to the diapausing stage C4). The biogeographic changes were further linked to large scale oceanic processes, particularly diminishing sea ice cover, upper ocean warming, and increasing and prolonging food availability, which could have potential consequences to the entire Arctic shelf/slope marine ecosystems. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  13. Ammonium excretion and oxygen respiration of tropical copepods and euphausiids exposed to oxygen minimum zone conditions

    Science.gov (United States)

    Kiko, Rainer; Hauss, Helena; Buchholz, Friedrich; Melzner, Frank

    2016-04-01

    Calanoid copepods and euphausiids are key components of marine zooplankton communities worldwide. Most euphausiids and several copepod species perform diel vertical migrations (DVMs) that contribute to the export of particulate and dissolved matter to midwater depths. In vast areas of the global ocean, and in particular in the eastern tropical Atlantic and Pacific, the daytime distribution depth of many migrating organisms corresponds to the core of the oxygen minimum zone (OMZ). At depth, the animals experience reduced temperature and oxygen partial pressure (pO2) and an increased carbon dioxide partial pressure (pCO2) compared to their near-surface nighttime habitat. Although it is well known that low oxygen levels can inhibit respiratory activity, the respiration response of tropical copepods and euphausiids to relevant pCO2, pO2, and temperature conditions remains poorly parameterized. Further, the regulation of ammonium excretion at OMZ conditions is generally not well understood. It was recently estimated that DVM-mediated ammonium supply could fuel bacterial anaerobic ammonium oxidation - a major loss process for fixed nitrogen in the ocean considerably. These estimates were based on the implicit assumption that hypoxia or anoxia in combination with hypercapnia (elevated pCO2) does not result in a down-regulation of ammonium excretion. We exposed calanoid copepods from the Eastern Tropical North Atlantic (ETNA; Undinula vulgaris and Pleuromamma abdominalis) and euphausiids from the Eastern Tropical South Pacific (ETSP; Euphausia mucronata) and the ETNA (Euphausia gibboides) to different temperatures, carbon dioxide and oxygen levels to study their survival, respiration and excretion rates at these conditions. An increase in temperature by 10 °C led to an approximately 2-fold increase of the respiration and excretion rates of U. vulgaris (Q10, respiration = 1.4; Q10, NH4-excretion = 1.6), P. abdominalis (Q10, respiration = 2.0; Q10, NH4-excretion = 2.4) and

  14. Ecological distribution of pelagic copepods and species relationship to acidification, liming and natural recovery in a boreal area

    OpenAIRE

    Svein Birger WÆRVÅGEN; Jens Petter NILSSEN

    2003-01-01

    Distribution and ecology of pelagic copepods were studied in a boreal area strongly affected by acidification in southern Norway. Differential regional composition of bedrock geology and Quaternary deposits combined with liming have produced aquatic sites with contrasting acidification and recovery histories. The omnivorous species Eudiaptomus gracilis showed a striking ability to tolerate both acidification and chemical recovery. The predominantly carnivorous species Heterocope saliens incre...

  15. Effects of the oxylipin-producing diatom Skeletonema marinoi on gene expression levels of the calanoid copepod Calanus sinicus.

    Science.gov (United States)

    Lauritano, Chiara; Carotenuto, Ylenia; Vitiello, Valentina; Buttino, Isabella; Romano, Giovanna; Hwang, Jiang-Shiou; Ianora, Adrianna

    2015-12-01

    Diatoms are eukaryotic unicellular plants that constitute one of the major components of marine phytoplankton, comprising up to 40% of annual productivity at sea and representing 25% of global carbon-fixation. Diatoms have traditionally been considered a preferential food for zooplankton grazers such as copepods, but, in the last two decades, this beneficial role has been challenged after the discovery that many species of diatoms produce toxic metabolites, collectively termed oxylipins, that induce reproductive failure in zooplankton grazers. Diatoms are the dominant natural diet of Calanus sinicus, a cold-temperate calanoid copepod that supports secondary production of important fisheries in the shelf ecosystems of the Northwest Pacific Ocean, Yellow Sea, Sea of Japan and South China Sea. In this study, the effect of the oxylipin-producing diatom Skeletonema marinoi on C. sinicus has been evaluated by analyzing expression level changes of genes involved in defense and detoxification systems. Results show that C. sinicus is more resistant to a diet of this diatom species in terms of gene expression patterns, compared to the congeneric species Calanus helgolandicus which is an important constituent of the temperate waters of the Atlantic Ocean and northern Mediterranean Sea. These findings contribute to the better understanding of genetic and/or phenotypic flexibility of copepod species and their capabilities to cope with stress by identifying molecular markers (such as stress and detoxification genes) as biosensors for environmental perturbations (e.g. toxins and contaminants) affecting marine copepods.

  16. Biological processes in the North Sea: vertical distribution and reproduction of neritic copepods in relation to environmental factors

    DEFF Research Database (Denmark)

    Koski, Marja; Jonasdottir, Sigrun; Bagøien, Espen

    2011-01-01

    in environmental variables probably overrode the differences between frontal and stratified stations. Copepod egg production on an annual basis seemed to be best predicted by the body size and specific fatty acids, with a high egg production, but low hatching success associated with a high EPA:DHA ratio. Total...

  17. Biology and infestation rate of Corallonoxia longicauda, an endoparasitic copepod of the West Indian reef coral Meandrina meandrites

    NARCIS (Netherlands)

    Butter, Maureen E.

    1979-01-01

    During 1½ year the biology of Corallonoxia longicauda, a copepod endoparasitic in the stony coral Meandrina meandrites was studied in Curaçao, Netherlands Antilles. The infestation rate of the corals as well as the numbers of parasites present were investigated at several depths and in several stati

  18. Temporal and ephemeral variations in copepod community in the estuaries of Mandovi and Zuari - west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Dalal, S.G.; Goswami, S.C.

    , we have exam- ined the relative importance of temporal and ephemeral variations in the abundance of copepod assemblages in two tropical estuaries—Mandovi and Zuari. METHOD Study area Mandovi and Zuari are two estuaries in Goa along the west coast...

  19. Global Proteome Profiling of a Marine Copepod and the Mitigating Effect of Ocean Acidification on Mercury Toxicity after Multigenerational Exposure.

    Science.gov (United States)

    Wang, Minghua; Lee, Jae-Seong; Li, Yan

    2017-05-16

    Previously, we found that ocean acidification (OA) mitigates mercury (Hg) toxicity to marine copepod Tigriopus japonicus under multigenerational exposure (four generations, F0-F3). To determine the response mechanisms of T. japonicus against long-term exposure to OA and Hg pollution, we investigated the proteome of F3 copepods after multigenerational exposure to four conditions: pCO2 400 μatm + control; pCO2 1000 μatm + control; pCO2 400 μatm +1.0 μg/L Hg; and pCO2 1000 μatm +1.0 μg/L Hg. Functional enrichment analysis indicated that OA enhanced the copepod's energy production mainly by increasing protein assimilation and proteolysis as a compensatory strategy, which explained its physiological resilience to reduced pH. Conversely, Hg treatment decreased many critical processes, including ferric iron binding, antioxidant activity, cellular homeostasis, and glutathione metabolism, and these toxic events could translate into higher-level responses, i.e., restrained reproduction in copepods. Importantly, the mediation of Hg toxicity in T. japonicus by OA could be explained by the enhanced lysosome-autophagy pathway proteomes that are responsible for repairing and removing damaged proteins and enzymes under stress. Overall, this study provided molecular insights into the response of T. japonicus to long-term exposure of OA and Hg, with a particular emphasis on the mitigating impact of the CO2-driven acidification on Hg toxicity.

  20. Exposure to crude oil micro-droplets causes reduced food uptake in copepods associated with alteration in their metabolic profiles.

    Science.gov (United States)

    Hansen, Bjørn Henrik; Altin, Dag; Nordtug, Trond; Øverjordet, Ida Beathe; Olsen, Anders J; Krause, Dan; Størdal, Ingvild; Størseth, Trond R

    2017-03-01

    Acute oil spills and produced water discharges may cause exposure of filter-feeding pelagic organisms to micron-sized dispersed oil droplets. The dissolved oil components are expected to be the main driver for oil dispersion toxicity; however, very few studies have investigated the specific contribution of oil droplets to toxicity. In the present work, the contribution of oil micro-droplet toxicity in dispersions was isolated by comparing exposures to oil dispersions (water soluble fraction with droplets) to concurrent exposure to filtered dispersions (water-soluble fractions without droplets). Physical (coloration) and behavioral (feeding activity) as well as molecular (metabolite profiling) responses to oil exposures in the copepod Calanus finmarchicus were studied. At high dispersion concentrations (4.1-5.6mg oil/L), copepods displayed carapace discoloration and reduced swimming activity. Reduced feeding activity, measured as algae uptake, gut filling and fecal pellet production, was evident also for lower concentrations (0.08mg oil/L). Alterations in metabolic profiles were also observed following exposure to oil dispersions. The pattern of responses were similar between two comparable experiments with different oil types, suggesting responses to be non-oil type specific. Furthermore, oil micro-droplets appear to contribute to some of the observed effects triggering a starvation-type response, manifested as a reduction in metabolite (homarine, acetylcholine, creatine and lactate) concentrations in copepods. Our work clearly displays a relationship between crude oil micro-droplet exposure and reduced uptake of algae in copepods.

  1. Effect of culture density and antioxidants on naupliar production and gene expression of the cyclopoid copepod, Paracyclopina nana.

    Science.gov (United States)

    Lee, Kyun-Woo; Rhee, Jae-Sung; Han, Jeonghoon; Park, Heum Gi; Lee, Jae-Seong

    2012-02-01

    Although attempts have been made to use mass cultures of marine copepods as live foods in marine aquaculture, some limitations such as low density culture still exist. The brackish water cyclopoid copepod, Paracyclopina nana has the potential for mass culturing as live food. In this study, we not only investigated the effect of culture density on the naupliar production and specific gene expressions of P. nana, but also the effect of several antioxidants under the conditions of a high density culture. The naupliar production of the copepod decreased with increasing culture density. The expression of glutathione reductase (GR), selenium-dependent glutathione peroxidase (SeGPx), glutathione S-transferase kappa (GST kappa), heat shock protein 40 (Hsp40), and Hsp70 genes of P. nana increased in the high density treatment but vitellogenin genes (Vg1 and Vg2) showed downregulation. In the condition with 20 inds./mL, vitamin C had a significant decrease but sodium selenite induced the naupliar production of P. nana greatly. The expressions of GR, SeGPx, Hsp70, and Vg genes increased with the vitamin C treatment. Sodium selenite caused a decrease of SeGPx and Hsp40 but GST kappa increased in the treatment with 20 inds./mL. These results suggest that sodium selenite is a positive antioxidant which can increase the culture efficiency of the copepod.

  2. Distinctly different behavioral responses of a copepod, Temora longicornis, to different strains of toxic dinoflagellates, Alexandrium spp

    DEFF Research Database (Denmark)

    Xu, Jiayi; Hansen, Per Juel; Nielsen, Lasse Tor;

    2017-01-01

    Zooplankton responses to toxic algae are highly variable, even towards taxonomically closely related species or different strains of the same species. Here, the individual level feeding behavior of a copepod, Temora longicornis, was examined which offered 4 similarly sized strains of toxic dinofl...

  3. Tolerance and genetic relatedness of three meiobenthic copepod populations exposed to sediment-associated contaminant mixtures: Role of environmental history

    Energy Technology Data Exchange (ETDEWEB)

    Kovatch, C.E.; Schizas, N.V.; Chandler, G.T.; Coull, B.C.; Quattro, J.M.

    2000-04-01

    Meiobenthic copepod populations (Microarthridion littoral) were collected from three South Carolina, USA, estuaries having different pollution stress histories (i.e., pristine sediments, high polycyclic aromatic hydrocarbon [PAH] sediments, high metals/moderate PAH sediments) and then assayed for survival and reproductive output in 14-d exposures to pristine and heavily PAH/metals-contaminated sediment mixture exhibited differential survival and reproductive outputs as a function of previous environmental histories and whether genetic relatedness among populations measured as DNA sequences of the mitochondrial gene, cytochrome apoenzyme b, were linked to copepod contaminant tolerance. Overall, adult survival and reproductive success in contaminated sediments were significantly reduced relative to controls for all three populations irrespective of environmental histories. Differential resistance to sediment-contaminant mixtures by the two copepod populations inhabiting the contaminated sites was not found, despite their previous exposures to mixed contaminants at {Sigma}PAH and {Sigma}Metal concentrations of 7,287 to 2,467 ng/g dry wt and 461 to 3,497 {micro}g/g, respectively. Significant genetic differentiation, however, was found between copepod populations from the control and the two contaminated sites. Generally, cross-population survival and reproductive outputs were not significantly different and could not be linked to genetic differentiation at the population level.

  4. Effects of adult stocking density on egg production and viability in cultures of the calanoid copepod Acartia tonsa (Dana)

    DEFF Research Database (Denmark)

    Jepsen, Per Meyer; Andersen, Nikolaj; Holm, Thue

    2007-01-01

    The effect of stocking density of the calanoid copepod Acartia tonsa was evaluated in a 96 h rearing experiment. Possible density-dependent egg production and egg viability were analysed at stocking densities of 100, 200, 300, 400 and 600 adults L−1. Temperature, oxygen saturation and algal conce...

  5. Resting eggs in a key player Calanoid copepod in coastal areas. The case of Acartia tonsa (Dana)

    DEFF Research Database (Denmark)

    Drillet, Guillaume; Hansen, Benni Winding

      Acartia tonsa is an invasive copepod of the European coastal waters, first described in France in 1926, it was found later in most of the European coastal areas. These invasions are believed to come from transport of resting eggs in ships ballast water. In this presentation, I will show the mai...

  6. The population dynamics of the parasitic copepode Lernaeocera lusci (Bassett-Smith, 1896) on its definitive host

    NARCIS (Netherlands)

    Van Damme, P.A.; Hamerlynck, O.; Ollevier, F.

    1996-01-01

    The mesoparasitic copepod Lernaeocera lusci (Bassett-Smith, 1896) was recovered from first-year bib (Trisopterus luscus L.) in the Voordelta (Southern Eight of the North Sea) from May until December 1989. Analysis of the seasonal abundance and of the population structure showed that transmission of

  7. Effect of alum on free-living and copepod-associated Vibrio cholerae O1 and O139.

    Science.gov (United States)

    Chowdhury, M A; Huq, A; Xu, B; Madeira, F J; Colwell, R R

    1997-08-01

    The effects of alum [KAl(SO4)2] on free-living and copepod-associated Vibrio cholerae O1 and O139 were investigated by using plate counts and immunofluorescence direct viable counting (DVC). Growth of alum-treated cells in 0.5/1000 Instant Ocean seawater was inhibited, i.e., no growth was obtained on Luria-Bertani (LB) agar or thiosulfate-citrate-bile salt-sucrose (TCBS) agar. However, a significant number of the inhibited cells maintained viability, as measured by DVC. In comparison, a significant number of V. cholerae organisms associated with zooplankton, most of which were crustacean copepods, were viable but nonculturable, with only a small number of cells retaining culturability on LB and TCBS agar. Both DVC and viable plate counts (CFU) were significantly greater for V. cholerae O1 and O139 associated with zooplankton than for V. cholerae in water alone, i.e., without copepods. It is concluded that alum is an effective coagulant but not an effective killing agent for V. cholerae and that association with copepods offers protection for V. cholerae O1 and O139 against alum and chlorine treatments.

  8. Copepod grazing and their impact on phytoplankton standing stock and production in a tropical coastal water during the different seasons.

    Science.gov (United States)

    Jagadeesan, L; Jyothibabu, R; Arunpandi, N; Parthasarathi, S

    2017-03-01

    The grazing rate of copepods on the total and size-fractionated phytoplankton biomass in a coastal environment (off Kochi, southwest coast of India) were measured during pre-monsoon (PRM), peak southwest monsoon (PKSWM), late southwest monsoon (LSWM) and post-southwest monsoon (PSWM). The phytoplankton standing stock (chlorophyll a-Chl. a) and growth rate (GR) were less during the PRM (Chl. a 0.58 mg m(-3); GR 0.23 ± 0.02) and PSWM (Chl. a 0.89 mg m(-3); GR 0.30 ± 0.05) compared to PKSWM (Chl. a 6.67 mg m(-3); GR 0.43 ± 0.02) and LSWM (Chl. a 4.09 mg m(-3); GR 0.40 ± 0.04). The microplankton contribution to the total Chl. a was significant during the PKSWM (41.83%) and LSWM (45.72%). Copepod density was lesser during the PRM (1354 No m(-3)) and PSWM (1606 No m(-3)) than during PKSWM and LSWM (4571 and 3432 No m(-3), respectively). Seasonal changes in phytoplankton biomass, phytoplankton size structure, and copepod community were closely related to the hydrographical transformations in the study domain. Dominant calanoid copepods in the study region ingested 8.4 to 14.2% of their daily ration from phytoplankton during the PRM and PSWM, which increased to >50% during the PKSWM and LSWM. The cyclopoid Oithona similis was abundant during the PKSWM, ingesting only 21% of their daily ration from phytoplankton. Temporal variation in the phytoplankton biomass and copepod species composition caused differences in community level top-down control. The copepod community ingestion on phytoplankton was high during the LSWM (18,583 μg C m(-3)d(-1)), followed by PKSWM (9050 μg C m(-3)d(-1)), PSWM (1813 μg C m(-3)d(-1)), and PRM (946 μg C m(-3)d(-1)). During the low Chl. a period (PRM and PSWM), dominant calanoid copepods showed a positive selectivity for the micro- and nano-phytoplankton size fractions, whereas during the high Chl. a period (PKSWM and LSWM), they showed a positive selection for nano-phytoplankton fractions. Irrespective

  9. Population dynamics of four dominant copepods in Prydz Bay, Antarctica, during austral summer from 1999 to 2006

    Institute of Scientific and Technical Information of China (English)

    YANG Guang; LI Chaolun; SUN Song

    2011-01-01

    Population dynamics of four dominant Antarctic copepods,Calanoides acutus,Calanus propinquus,Metridia gerlachei and Rhincalanus gigas were studied based on zooplankton samples collected in the Prydz Bay during austral summer from 1999 to 2006.We found that C.acutus was the most abundant species among these four copepods,followed by C.propinquus,M.gerlachei and R.gigas.R.gigas occurred mainly in the warmer oceanic regions and showed distribution pattems discrete from the other three species,whose distribution in the whole survey area overlapped.By December 15th (about one month before our sampling) of the years 1999,2003 and 2006,sea ice retreated earlier and polynyas existed in the neritic region one month before sampling.These periods were characterized by numerical dominance of C.acutus,C.propinquus and M.gerlachei,elevated proportions of Copepodite Ⅰ and Copepodite Ⅱ stages especially in the neritic region.While for the years 2000,2002,and 2005,the ice edge located more northerly and polynyas did not exist in the neritic region,the copepods abundance was lower,indicating poor recruitment.Population structure of R.gigas was mainly composed of advanced stages Copepodite V and female during all cruises.Log10 (x+l) transformed densities of C.acutus,C.propinquus and M.gerlachei showed positive correlation with temperature and chlorophyll a concentration,while mean population stages of these copopods were negatively correlated with these environmental variables.Younger copepodite stages of C.acutus,C.propinquus and M.gerlachei appeared more often in neritic regions.We confirmed that the polynyas had a great contribution to phytoplankton blooms,which promote copepods reproduction and recruitment success.The study suggested that population dynamics of the four copepods have good correspondence with sea ice and polynya variations during all cruises of the Prydz Bay.

  10. The copepod Tigriopus: a promising marine model organism for ecotoxicology and environmental genomics.

    Science.gov (United States)

    Raisuddin, Sheikh; Kwok, Kevin W H; Leung, Kenneth M Y; Schlenk, Daniel; Lee, Jae-Seong

    2007-07-20

    There is an increasing body of evidence to support the significant role of invertebrates in assessing impacts of environmental contaminants on marine ecosystems. Therefore, in recent years massive efforts have been directed to identify viable and ecologically relevant invertebrate toxicity testing models. Tigriopus, a harpacticoid copepod has a number of promising characteristics which make it a candidate worth consideration in such efforts. Tigriopus and other copepods are widely distributed and ecologically important organisms. Their position in marine food chains is very prominent, especially with regard to the transfer of energy. Copepods also play an important role in the transportation of aquatic pollutants across the food chains. In recent years there has been a phenomenal increase in the knowledge base of Tigriopus spp., particularly in the areas of their ecology, geophylogeny, genomics and their behavioural, biochemical and molecular responses following exposure to environmental stressors and chemicals. Sequences of a number of important marker genes have been studied in various Tigriopus spp., notably T. californicus and T. japonicus. These genes belong to normal biophysiological functions (e.g. electron transport system enzymes) as well as stress and toxic chemical exposure responses (heat shock protein 20, glutathione reductase, glutathione S-transferase). Recently, 40,740 expressed sequenced tags (ESTs) from T. japonicus, have been sequenced and of them, 5,673 ESTs showed significant hits (E-value, >1.0E-05) to the red flour beetle Tribolium genome database. Metals and organic pollutants such as antifouling agents, pesticides, polycyclic aromatic hydrocarbons (PAH) and polychrlorinated biphenyls (PCB) have shown reproducible biological responses when tested in Tigriopus spp. Promising results have been obtained when Tigriopus was used for assessment of risk associated with exposure to endocrine-disrupting chemicals (EDCs). Application of environmental

  11. The copepod Tigriopus: A promising marine model organism for ecotoxicology and environmental genomics

    Energy Technology Data Exchange (ETDEWEB)

    Raisuddin, Sheikh [Department of Chemistry and the National Research Lab of Marine Molecular and Environmental Bioscience, College of Natural Sciences, Hanyang University, Seoul 133-791 (Korea, Republic of); Kwok, Kevin W.H. [Swire Institute of Marine Science, Department of Ecology and Biodiversity, University of Hong Kong, Pokfulam, Hong Kong (China); Leung, Kenneth M.Y. [Swire Institute of Marine Science, Department of Ecology and Biodiversity, University of Hong Kong, Pokfulam, Hong Kong (China); Schlenk, Daniel [Department of Environmental Sciences, University of California, Riverside, CA 92521 (United States); Lee, Jae-Seong [Department of Chemistry and the National Research Lab of Marine Molecular and Environmental Bioscience, College of Natural Sciences, Hanyang University, Seoul 133-791 (Korea, Republic of)]. E-mail: jslee2@hanyang.ac.kr

    2007-07-20

    There is an increasing body of evidence to support the significant role of invertebrates in assessing impacts of environmental contaminants on marine ecosystems. Therefore, in recent years massive efforts have been directed to identify viable and ecologically relevant invertebrate toxicity testing models. Tigriopus, a harpacticoid copepod has a number of promising characteristics which make it a candidate worth consideration in such efforts. Tigriopus and other copepods are widely distributed and ecologically important organisms. Their position in marine food chains is very prominent, especially with regard to the transfer of energy. Copepods also play an important role in the transportation of aquatic pollutants across the food chains. In recent years there has been a phenomenal increase in the knowledge base of Tigriopus spp., particularly in the areas of their ecology, geophylogeny, genomics and their behavioural, biochemical and molecular responses following exposure to environmental stressors and chemicals. Sequences of a number of important marker genes have been studied in various Tigriopus spp., notably T. californicus and T. japonicus. These genes belong to normal biophysiological functions (e.g. electron transport system enzymes) as well as stress and toxic chemical exposure responses (heat shock protein 20, glutathione reductase, glutathione S-transferase). Recently, 40,740 expressed sequenced tags (ESTs) from T. japonicus, have been sequenced and of them, 5673 ESTs showed significant hits (E-value, >1.0E-05) to the red flour beetle Tribolium genome database. Metals and organic pollutants such as antifouling agents, pesticides, polycyclic aromatic hydrocarbons (PAH) and polychrlorinated biphenyls (PCB) have shown reproducible biological responses when tested in Tigriopus spp. Promising results have been obtained when Tigriopus was used for assessment of risk associated with exposure to endocrine-disrupting chemicals (EDCs). Application of environmental

  12. Alcaloides iboga de Peschiera affinis (Apocynaceae - Atribuição inequívoca dos deslocamentos químicos dos átomos de hidrogênio e carbono: atividade antioxidante Iboga alkaloids from Peschiera affinis (Apocynaceae - unequivocal 1H and 13C chemical shift assignments: antioxidant activity

    Directory of Open Access Journals (Sweden)

    Allana Kellen L. Santos

    2009-01-01

    Full Text Available Six known alkaloids iboga type and the triterpen α- and β-amyrin acetate were isolated from the roots and stems of Peschiera affinis. Their structures were characterized on the basis of spectral data mainly NMR and mass spectra. 1D and 2D NMR spectra were also used to unequivocal ¹H and 13C chemical shift assignments of alkaloids. The ethanolic extract of roots, alkaloidic and no-alkaloidic fractions and iso-voacristine hydroxyindolenine and voacangine were evaluated for their antioxidative properties using an autographic assay based on β-carotene bleaching on TLC plates, and also spectrophotometric detection by reduction of the stable DPPH (2,2-diphenyl-1-picrylhydrazyl free radical.

  13. Primers to block the amplification of symbiotic apostome ciliate 18S rRNA gene in a PCR-based copepod diet study

    Science.gov (United States)

    Yi, Xiaoyan; Zhang, Huan; Liu, Guangxing

    2014-05-01

    Pelagic copepods play an important role in the marine food web. However, a full understanding of the ecological status of this zooplankton group depends on the careful study of their natural diets. In previous PCR-based copepod diet studies, we found many apostome ciliates that live symbiotically under the exoskeleton of the copepods, and their sequences were often over-represented in the 18S rRNA gene (18S rDNA) libraries. As a first step to address this issue, we designed three apostome ciliate 18S rDNA blocking primers, and tested their blocking efficiency against apostome ciliate 18s rDNA under various PCR conditions. Using a semi-quantitative PCR method, we optimized the conditions to efficiently amplify the 18S rDNA of the prey while simultaneously excluding the symbiotic apostome ciliates. This technique will facilitate PCR-based diet studies of copepods and other zooplankton in their natural environments.

  14. Zooplankton variability and copepod assemblage in the coastal and estuarine waters of Goa along the central-west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Achuthankutty, C.T.; Ramaiah, Neelam; Padmavati, G.

    in the estuary, salinity attained almost limnetic conditions as the monsoon progressed and slowly recovered during the postmonsoon season. These changes have tremendous influence on zooplankton production and copepod species distribution. While the highest...

  15. Expression of hsp70 and ferritin in embryos of the copepod Acartia tonsa (Dana) during transition between subitaneous and quiescent state

    DEFF Research Database (Denmark)

    Nilsson, Birgitte; Jepsen, Per Meyer; Rewitz, Kim Furbo

    2014-01-01

    Subitaneous eggs of the neritic calanoid copepod Acartia tonsa (Dana) are capable of entering a resting state called quiescence to overcome adverse environmental conditions. Although physiological changes associated with this transition have been described, the molecular mechanisms are thus far...

  16. A cost-effectiveness analysis of live feeds in juvenile turbot Scophthalmus maximus (Linnaeus, 1758) farming: copepods versus Artemiapepods versus Artemiacopepods versus Artemiacopepods versus Artemia

    DEFF Research Database (Denmark)

    Gedefaw Abate, Tenaw; Nielsen, Rasmus; Nielsen, Max;

    2016-01-01

    , their current usage is quite limited. One of the reasons has been lack of economic knowledge concerning the cost-effectiveness of copepod application compared to other commonly used feed items such as the brine shrimp Artemia. In this study, a cost-effectiveness analysis is made on two alternative live feed...... but they are also economically a cost-effective alternative. Thus, a commercial use of copepods will significantly reduce the production costs for turbot. Furthermore, the unexploited economic potential can be utilized for the successful farming of other high-valued marine finfish species such as tuna, flounders...... items (copepods and Artemia) in juvenile turbot farming. Unit cost of production and profit are compared between the two feeding regimes using a unique data set from an existing turbot fry production facility in Denmark. The result reveals that copepods are not only biochemically superior...

  17. Mudanças ontogênicas no trato digestório e dieta de Apareiodon affinis (Steindachner, 1879 (Osteichthyes, Parodontidae - DOI: 10.4025/actascibiolsci.v26i3.1542 Ontogenic changes in digestive tract and diet shifts of Apareiodon affinis (Steindachner, 1879 (Osteichthyes, Parodontidae - DOI: 10.4025/actascibiolsci.v26i3.1542

    Directory of Open Access Journals (Sweden)

    Andréa Bialetzki

    2004-04-01

    Full Text Available Aspectos da alimentação de larvas e juvenis de Apareiodon affinis são descritos. As amostragens foram realizadas no Ressaco do Leopoldo, alto rio Paraná, entre fevereiro de 1991 e fevereiro de 1992, utilizando rede de plâncton. Nas larvas em pré-flexão e flexão, a boca é pequena e terminal, passando a inferior no estágio de pós-flexão e nos juvenis. O tubo digestivo é simples e reto nas larvas em pré-flexão e diferenciado naquelas em pós-flexão. A dieta foi constituída principalmente por algas, caracterizando essa espécie como algívora durante todo o seu desenvolvimento. A análise da digestibilidade não evidenciou o horário preferencial de alimentação dos difirentes estágios de desenvolvimento, provavelmente em função do tipo de amostragem utilizada e do alimento consumido pelos indivíduosFeeding aspects of Apareiodon affinis larvae and juveniles are described in this work. Samples collected by plankton net were taken from February, 1991 to February, 1992 in Ressaco do Leopoldo, Paraná River. The mouth is small and terminal in preflexion and flexion larvae and inferior at the end of this development period and in juveniles. The digestive tract is simple and straight in preflexion larvae, but different in those in postflexion. The diet was basically algae, characterizing this species as algivorous during all its development. The analysis of the digestibility did not show the preferential time of feeding of the different development stages. This was probably because of the sampling type utilized and because of the food consumed by the individuals

  18. Notes on the Egg Bearing Cyclopoid Copepod, Oithona similis Claus, 1866 of the Arabian Sea

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    Jean J. JOSE

    2014-03-01

    Full Text Available Morphology of the marine egg bearing cyclopoid copepod Oithona similis occurring along the southwest coast of India [Vizhinjam (8º21'56"N; 76º59'39"E, Neendakara (8º57'29"N; 76º31'13"E, Cochin (9º56'16"N; 76º13'55"E and Calicut (11º13'33"N; 75º46'30"E] from January to December 2010 at different seasons (pre monsoon, monsoon and post monsoon were studied. Detailed comparison of the structure of different appendages of O. similis with those already available for the species from Norway, Japan, China, Spain and Russia revealed minute differences in the armature of appendages, number and arrangement of spines, setae of swimming legs and anal laminae. The total length of the specimen collected from all the four stations in the study ranged from 615 to 650μ. The smallest specimens were obtained from Calicut.

  19. Mitochondrial DNA polymorphism (CO1) of three dominant copepod species in the South Atlantic

    Science.gov (United States)

    Stupnikova, A. N.; Kulagin, D. N.; Neretina, T. V.; Mugue, N. S.

    2013-07-01

    The Southern Ocean is characterized by the complex system of oceanic fronts that maintain the latitudinal zonality of biotopes. These fronts are boundaries of water masses with different hydrophysical characteristics. We explore the genetic differentiation of the dominant zooplankton species in regards to the complex hydrophysical zonality of the Southern Ocean. The barcoding region of mitochondrial CO1 gene was sequenced for three copepod species, Calanus simillimus, Rhincalanus gigas, and Metridia lucens. These species are the most abundant in the Southern Ocean and form the basis of the zooplankton community. Genetic differentiation was found neither for Calanus simillimus nor for Rhincalanus gigas. The mitochondrial haplotypes of Metridia lucens cluster in two genetically distant groups (Subantarctic and Antarctic) found together only in the Polar Front Zone.

  20. Syltodinium listii gen. et spec. nov., a marine ectoparasitic dinoflagellate on eggs of copepods and rotifers

    Science.gov (United States)

    Drebes, Gerhard

    1988-09-01

    Syltodinium listii is described as a new marine ectoparasitic dinoflagellate. In culture experiments the species was found feeding on eggs of planktonic copepods and rotifers. The dinospore penetrates the host by a peduncle, and transforms into a trophont by sucking out the egg contents phagotrophically. After detaching from the host, the mature trophont settles down to become a palmelloid multiplication stage. By repeated binary fission, up to 16 or 32 gymnodinoid, colourless dinospores are formed inside a gelatinous envelope. The parasite retains its dinoflagellate (monadoid) nature throughout its whole vegetative life cycle. Even during the trophic and multiplication phase the species remains latently motile. Despite some resemblance to Dissodinium, there are sufficient reasons for the establishment of the new genus Syltodinium.

  1. Age- and size-dependent mating performance and fertility in a pelagic copepod, Temora longicornis

    DEFF Research Database (Denmark)

    Sichlau, Mie Hylstofte; Kiørboe, Thomas

    2011-01-01

    Prepress abstract: In many species, size and age have been shown to be strong determinants of the reproductive success for both sexes. Here we examine age- and size dependent reproductive performance (egg- and sperm production, mating success) in a pelagic copepod. Compared to smaller males, larger...... males produce larger spermatophores containing more spermatozoa, and fertilize a larger fraction of available females. Females mating with large males produce more offspring than those mating with small males. Similarly, large females have higher egg production rates as well as a higher life-time egg...... production than small females. Ageing effects are evident in this species: Mortality rate increases and fertility decreases rapidly with age. The average adult longevity under optimal laboratory conditions was 30 days in both males and females, but females produce eggs for only 18 days, and males can...

  2. Life cycle of Schizochytriodinium calani nov. gen. nov. spec., a dinoflagellate parasitizing copepod eggs

    Science.gov (United States)

    Elbrächter, Malte

    1988-09-01

    During the Polarstern-cruise ARK IV/2 June 1987, in the Fram Strait, dinophytes parasitizing copepod eggs were observed. In the laboratory on board, vegetative reproduction was documented and re-infection of Calanus glacialis and C. hyperboreus eggs was experimentally established. During food uptake, a primary cyst produces successively several secondary cysts, all separating immediately after formation from the primary cyst. In every one of these free floating secondary cysts up to 256 dinospores are formed by palintomy. Re-infection only occurred after a “maturation time” of at least 2 days after formation of the dinospores. The life cycle is compared to that of other similar parasitic dinophyte genera: Apodinium Chatton, Chytriodinium Chatton, Dissodinium Klebs in Pascher and Myxodinium Cachon, Cachon & Bouquaheux. As the taxon under discussion does not fit in with any species or genus known so far, it is described as Schizochytriodinium calani nov. gen. nov. spec.

  3. Bacterial exopolymer utilization by a harpacticoid copepod: A methodology and results

    Energy Technology Data Exchange (ETDEWEB)

    Decho, A.W.; Moriarty, D.J.W. (C.S.I.R.O. Marine Labs., Cleveland (Australia))

    1990-07-01

    Exopolymer mucus secretions of bacteria and diatoms are potential foods for benthic animals. These secretions are coincidently ingested by animals during consumption of microbial cells and sediments. The utilization of microbial secretions was investigated with exopolymer derived from a marine bacterium (pseudomonas sp.) from seagrass beds and a harpacticoid copepod Laophonte sp. from the same habitat. A new technique was developed to examine ingestion, absorption, and absorption efficiencies of these bacterial secretions by consumers. Exopolymer mucus (from the bacterium in stationary phase) was labeled with {sup 14}C, collected, purified, and bound onto bacterium-sized beads. The exopolymer slime coating mimicked the coatings associated with many marine bacteria. Results from feeding experiments where the coated beads were mixed with sediment demonstrated that the mucus-exopolymer secretions of bacteria were ingested and utilized by Laophonte sp. Absorption efficiencies, determined directly, were > 80% in the presence of other food resources, indicating that exopolymer is potentially a highly labile C resource for this animal.

  4. Rapid adaptation to oil exposure in the cosmopolitan copepod Acartia tonsa

    DEFF Research Database (Denmark)

    Krause, K. E.; Dinh, Khuong Van; Nielsen, Torkel Gissel

    to marine copepods. The key fitness-related traits were quantified: survival, size at maturity, grazing rate and the reproductive success. Exposure to the concentration of pyrene saturated in seawater (100+ nM) resulted in 100 % mortality before adulthood in the first generation. In the other treatments...... (≤ 100nM), the first generation had a higher grazing rate than the second generation. Exposure to pyrene had no effect on the grazing rate. At the concentration of 100 nM, pyrene exposure caused reductions in survival, size at maturity of females, egg production and hatching success. The reduction...... in size at maturity of females was less pronounced in the second generation. Strikingly, both survival, egg production and hatching success were recovered in the second generation, indicating a rapid selection towards individuals with adaptations to deal with pyrene exposure. Our results show...

  5. Seasonal copepod lipid pump promotes carbon sequestration in the deep North Atlantic.

    Science.gov (United States)

    Jónasdóttir, Sigrún Huld; Visser, André W; Richardson, Katherine; Heath, Michael R

    2015-09-29

    Estimates of carbon flux to the deep oceans are essential for our understanding of global carbon budgets. Sinking of detrital material ("biological pump") is usually thought to be the main biological component of this flux. Here, we identify an additional biological mechanism, the seasonal "lipid pump," which is highly efficient at sequestering carbon into the deep ocean. It involves the vertical transport and metabolism of carbon rich lipids by overwintering zooplankton. We show that one species, the copepod Calanus finmarchicus overwintering in the North Atlantic, sequesters an amount of carbon equivalent to the sinking flux of detrital material. The efficiency of the lipid pump derives from a near-complete decoupling between nutrient and carbon cycling—a "lipid shunt," and its direct transport of carbon through the mesopelagic zone to below the permanent thermocline with very little attenuation. Inclusion of the lipid pump almost doubles the previous estimates of deep-ocean carbon sequestration by biological processes in the North Atlantic.

  6. Functional coadaptation between cytochrome c and cytochrome c oxidase within allopatric populations of a marine copepod.

    Science.gov (United States)

    Rawson, Paul D; Burton, Ronald S

    2002-10-01

    Geographically isolated populations may accumulate alleles that function well on their own genetic backgrounds but poorly on the genetic backgrounds of other populations. Consequently, interpopulation hybridization may produce offspring of low fitness as a result of incompatibilities arising in allopatry. Genes participating in these epistatic incompatibility systems remain largely unknown. In fact, despite the widely recognized importance of epistatic interactions among gene products, few data directly address the functional consequences of such interactions among natural genetic variants. In the marine copepod, Tigriopus californicus, we found that the cytochrome c variants isolated from two different populations each had significantly higher activity with the cytochrome c oxidase derived from their respective source population. Three amino acid substitutions in the cytochrome c protein appear to be sufficient to confer population specificity. These results suggest that electron transport system (ETS) proteins form coadapted sets of alleles within populations and that disruption of the coadapted ETS gene complex leads to functional incompatibilities that may lower hybrid fitness.

  7. Phylogeography of the intertidal copepod Tigriopus californicus reveals substantially reduced population differentiation at northern latitudes.

    Science.gov (United States)

    Edmands, S

    2001-07-01

    Previous studies of the intertidal copepod Tigriopus californicus revealed one of the highest levels of mitochondrial DNA differentiation ever reported among conspecific populations. The present study extends the geographical sampling northward, adding populations from northern California to south-east Alaska. The mitochondrial phylogeny for the entire species range, based on cytochrome oxidase I sequences for a total of 49 individuals from 27 populations, again shows extreme differentiation among populations (up to 23%). However, populations from Oregon northwards appear to be derived and have interpopulation divergences five times lower than those between southern populations. Furthermore, although few individuals were sequenced from each locality, populations from Puget Sound northward had significantly reduced levels of within-population variation. These patterns are hypothesized to result from the contraction and expansion of populations driven by recent ice ages.

  8. Trade-offs, geography, and limits to thermal adaptation in a tide pool copepod.

    Science.gov (United States)

    Kelly, Morgan W; Grosberg, Richard K; Sanford, Eric

    2013-06-01

    Antagonistic correlations among traits may slow the rate of adaptation to a changing environment. The tide pool copepod Tigriopus californicus is locally adapted to temperature, but within populations, the response to selection for increased heat tolerance plateaus rapidly, suggesting either limited variation within populations or costs of increased tolerance. To measure possible costs of thermal tolerance, we selected for increased upper lethal limits for 10 generations in 22 lines of T. californicus from six populations. Then, for each line, we measured six fitness-related traits. Selected lines showed an overall increase in male and female body sizes, fecundity, and starvation resistance, suggesting a small benefit from (rather than costs of) increased tolerance. The effect of selection on correlated traits also varied significantly by population for five traits, indicating that the genetic basis for the selection response differed among populations. Our results suggest that adaptation was limited by the presence of variation within isolated populations rather than by costs of increased tolerance.

  9. Changes in selection regime cause loss of phenotypic plasticity in planktonic freshwater copepods.

    Science.gov (United States)

    Sereda, Sergej Vital'evič; Wilke, Thomas; Schultheiß, Roland

    2014-01-01

    Rapid phenotypic adaptation is critical for populations facing environmental changes and can be facilitated by phenotypic plasticity in the selected traits. Whereas recurrent environmental fluctuations can favour the maintenance or de novo evolution of plasticity, strong selection is hypothesized to decrease plasticity or even fix the trait (genetic assimilation). Despite advances in the theoretical understanding of the impact of plasticity on diversification processes, comparatively little empirical data of populations undergoing diversification mediated by plasticity are available. Here we use the planktonic freshwater copepod Acanthodiaptomus denticornis from two lakes as model system to study UV stress responses of two phenotypically different populations under laboratory conditions. Our study reveals heritable lake- and sex-specific differences of behaviour, physiological plasticity, and mortality. We discuss specific selective scenarios causing these differences and argue that phenotypic plasticity will be higher when selection pressure is moderate, but will decrease or even be lost under stronger pressure.

  10. Diet influence on egg production of the copepod Acartia tonsa (Dana, 1896

    Directory of Open Access Journals (Sweden)

    Priscila F. Teixeira

    2010-06-01

    Full Text Available Egg production in the copepod Acartia tonsa was evaluated using different densities of the microalgae Thalassiosira weissflogii, Chaetoceros muelleri and Isochrysis galbana. Male and female were kept under controlled conditions (salinity 30, 20°C, photoperiod 12L:12D, acclimated to the experimental conditions and left over a period of 24 h to allow copulation. Algal densities tested were equivalent in biovolume and corresponded to 0, 2.5, 5, 10, 20, 40 and 60.10³ cells.mL-1 of T weissflogii. Ten acclimated female were separated, transferred to glass bottles and exposed for further 24 h to the corresponding experimental medium. After this period, the eggs were fixed and counted. Copepod egg production reached a threshold value when T weissflogii, C. muelleri and I. galbana were supplied at 10.10³, 140.10³ and 640.10³ cells.mL-1, respectively. Mean egg production corresponded to 28.0 ± 0.5, 20.1 ± 1.0 and 22.0 ± 3.5 eggs.female-1 .day-1, respectively. Copepods fed T weissflogii showed the highest mean egg production while those fed I. galbana reached a maximum egg production when the algae were supplied at a density two- to fourfold higher, considering the biovolume of T weissflogii and C. muelleri. These differences are explained considering the different sizes of the microalgae used to feed the copepods.A produção de ovos do copépode Acartia tonsa foi avaliada utilizando diferentes densidades das microalgas Thalassiosira weissflogii, Chaetoceros muelleri e Isochrysis galbana. Machos e fêmeas foram colocados sob condições controladas (salinidade 30, 20°C, fotoperíodo 12L:12D, aclimatados às condições experimentais e mantidos juntos por 24 h para permitir a copula. As densidades de algas foram equivalentes em biovolume e corresponderam a 0, 2,5, 5, 10, 20, 40 e 60,10³ células.mL-1 de T. weissflogii. Dez fêmeas aclimatadas foram separadas, transferidas para frascos de vidro e expostas por mais 24 h ao meio experimental

  11. Biosynthesis of coelenterazine in the deep-sea copepod, Metridia pacifica

    Energy Technology Data Exchange (ETDEWEB)

    Oba, Yuichi; Kato, Shin-ichi; Ojika, Makoto [Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa-ku, Nagoya 464-860 (Japan); Inouye, Satoshi, E-mail: sinouye@chisso.co.jp [Yokohama Research Center, Chisso Co., 5-1 Okawa, Kanazawa-ku, Yokohama 236-8605 (Japan)

    2009-12-18

    Coelenterazine is an imidazopyrazinone compound (3,7-dihydroimidazopyrazin-3-one structure) that is widely distributed in marine organisms and used as a luciferin for various bioluminescence reactions. We have used electrospray ionization-ion trap-mass spectrometry to investigate whether the deep-sea luminous copepod Metridia pacifica is able to synthesize coelenterazine. By feeding experiments using deuterium labeled amino acids of L-tyrosine and L-phenylalanine, we have shown that coelenterazine can be synthesized from two molecules of L-tyrosine and one molecule of L-phenylalanine in M. pacifica. This is the first demonstration that coelenterazine is biosynthesized from free L-amino acids in a marine organism.

  12. Transgenerational effects alleviate severe fecundity loss during ocean acidification in a ubiquitous planktonic copepod.

    Science.gov (United States)

    Thor, Peter; Dupont, Sam

    2015-06-01

    Ocean acidification (OA) caused by anthropogenic CO2 emission is projected for thousands of years to come, and significant effects are predicted for many marine organisms. While significant evolutionary responses are expected during such persistent environmental change, most studies consider only short-term effects. Little is known about the transgenerational effects of parental environments or natural selection on the capacity of populations to counter detrimental OA effects. In this study, six laboratory populations of the calanoid copepod Pseudocalanus acuspes were established at three different CO2 partial pressures (pCO2 of 400, 900 and 1550 μatm) and grown for two generations at these conditions. Our results show evidence of alleviation of OA effects as a result of transgenerational effects in P. acuspes. Second generation adults showed a 29% decrease in fecundity at 900 μatm CO2 compared to 400 μatm CO2 . This was accompanied by a 10% increase in metabolic rate indicative of metabolic stress. Reciprocal transplant tests demonstrated that this effect was reversible and the expression of phenotypic plasticity. Furthermore, these tests showed that at a pCO2 exceeding the natural range experienced by P. acuspes (1550 μatm), fecundity would have decreased by as much as 67% compared to at 400 μatm CO2 as a result of this plasticity. However, transgenerational effects partly reduced OA effects so that the loss of fecundity remained at a level comparable to that at 900 μatm CO2 . This also relieved the copepods from metabolic stress, and respiration rates were lower than at 900 μatm CO2 . These results highlight the importance of tests for transgenerational effects to avoid overestimation of the effects of OA.

  13. Seasonal phytoplankton blooms in the North Atlantic linked to the overwintering strategies of copepods

    Directory of Open Access Journals (Sweden)

    Kevin D. Friedland

    2016-04-01

    Full Text Available Abstract The North Atlantic Ocean contains diverse patterns of seasonal phytoplankton blooms with distinct internal dynamics. We analyzed blooms using remotely-sensed chlorophyll a concentration data and change point statistics. The first bloom of the year began during spring at low latitudes and later in summer at higher latitudes. In regions where spring blooms occurred at high frequency (i.e., proportion of years that a bloom was detected, there was a negative correlation between bloom timing and duration, indicating that early blooms last longer. In much of the Northeast Atlantic, bloom development extended over multiple seasons resulting in peak chlorophyll concentrations in summer. Spring bloom start day was found to be positively correlated with a spring phenology index and showed both positive and negative correlations to sea surface temperature and the North Atlantic Oscillation in different regions. Based on the characteristics of spring and summer blooms, the North Atlantic can be classified into two regions: a seasonal bloom region, with a well-defined bloom limited to a single season; and a multi-seasonal bloom region, with blooms extending over multiple seasons. These regions differed in the correlation between bloom start and duration with only the seasonal bloom region showing a significant, negative correlation. We tested the hypothesis that the near-surface springtime distribution of copepods that undergo diapause (Calanus finmarchicus, C. helgolandicus, C. glacialis, and C. hyperboreus may contribute to the contrast in bloom development between the two regions. Peak near-surface spring abundance of the late stages of these Calanoid copepods was generally associated with areas having a well-defined seasonal bloom, implying a link between bloom shape and their abundance. We suggest that either grazing is a factor in shaping the seasonal bloom or bloom shape determines whether a habitat is conducive to diapause, while recognizing

  14. A gene-based SNP resource and linkage map for the copepod Tigriopus californicus

    Directory of Open Access Journals (Sweden)

    Foley Brad R

    2011-11-01

    Full Text Available Abstract Background As yet, few genomic resources have been developed in crustaceans. This lack is particularly evident in Copepoda, given the extraordinary numerical abundance, and taxonomic and ecological diversity of this group. Tigriopus californicus is ideally suited to serve as a genetic model copepod and has been the subject of extensive work in environmental stress and reproductive isolation. Accordingly, we set out to develop a broadly-useful panel of genetic markers and to construct a linkage map dense enough for quantitative trait locus detection in an interval mapping framework for T. californicus--a first for copepods. Results One hundred and ninety Single Nucleotide Polymorphisms (SNPs were used to genotype our mapping population of 250 F2 larvae. We were able to construct a linkage map with an average intermarker distance of 1.8 cM, and a maximum intermarker distance of 10.3 cM. All markers were assembled into linkage groups, and the 12 linkage groups corresponded to the 12 known chromosomes of T. californicus. We estimate a total genome size of 401.0 cM, and a total coverage of 73.7%. Seventy five percent of the mapped markers were detected in 9 additional populations of T. californicus. Of available model arthropod genomes, we were able to show more colocalized pairs of homologues between T. californicus and the honeybee Apis mellifera, than expected by chance, suggesting preserved macrosynteny between Hymenoptera and Copepoda. Conclusions Our study provides an abundance of linked markers spanning all chromosomes. Many of these markers are also found in multiple populations of T. californicus, and in two other species in the genus. The genomic resource we have developed will enable mapping throughout the geographical range of this species and in closely related species. This linkage map will facilitate genome sequencing, mapping and assembly in an ecologically and taxonomically interesting group for which genomic resources are

  15. Toxicity of nickel in the marine calanoid copepod Acartia tonsa: Nickel chloride versus nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, C. [Istituto per la Protezione e Ricerca Ambientale ISPRA-STS Livorno, Piazzale dei marmi 12, 57123 Livorno (Italy); Academic Centre for Innovation and Development in the Food Industry (CAISIAL), Università degli Studi di Napoli Federico II, 80055 Portici (Italy); Vitiello, V. [Istituto per la Protezione e Ricerca Ambientale ISPRA-STS Livorno, Piazzale dei marmi 12, 57123 Livorno (Italy); Casals, E. [Institut Català de Nanotecnologia, Campus de la Universitat Autònoma de Barcelone, 08193 Bellaterra (Spain); Puntes, V.F. [Institut Català de Nanotecnologia, Campus de la Universitat Autònoma de Barcelone, 08193 Bellaterra (Spain); Institut Català de Recerca i Estudis Avançats (ICREA), Passeig Lluís Companys, 23, 08010 Barcelona (Spain); Iamunno, F. [Stazione Zoologica Anton Dohrn, Villa Comunale, Napoli (Italy); Pellegrini, D. [Istituto per la Protezione e Ricerca Ambientale ISPRA-STS Livorno, Piazzale dei marmi 12, 57123 Livorno (Italy); Changwen, W. [Zhejiang Ocean University, 1 Rd. South Haida, Lincheng New Area, Dinghai District Zhoushan City, 316022 (China); Benvenuto, G. [Stazione Zoologica Anton Dohrn, Villa Comunale, Napoli (Italy); Buttino, I., E-mail: isabella.buttino@isprambiente.it [Istituto per la Protezione e Ricerca Ambientale ISPRA-STS Livorno, Piazzale dei marmi 12, 57123 Livorno (Italy)

    2016-01-15

    Highlights: • Acartia tonsa copepod is more sensitive to NiCl{sub 2} than to nickel nanoparticles. • At the tested concentration egg production was not affected by both form of nickel. • Egg viability is the most sensitive end-point for both form of nickel. • Nickel dissolved in seawater increased with nanoparticle concentration. • Acartia tonsa adults were able to ingest nanoparticles. - Abstract: Nickel compounds are widely used in industries and have been massively introduced in the environment in different chemical forms. Here we report the effect of two different chemical forms of nickel, NiCl{sub 2} and nickel nanoparticles (NiNPs), on the reproduction of the marine calanoid copepod Acartia tonsa. The behavior of nickel nanoparticles was analyzed with different techniques and with two protocols. In the “sonicated experiment” (SON) NiNP solution was sonicated while in the “non-sonicated experiment” (NON-SON) the solution was vigorously shaken by hand. Final nominal concentrations of 5, 10 and 50 mg L{sup −1} and 1, 5 and 10 mg L{sup −1} NiNPs were used for the acute and semichronic tests, respectively. Nanoparticle size did not change over time except for the highest concentration of 50 mg L{sup −1} NiNPs, in which the diameter increased up to 843 nm after 48 h. The concentration of Ni dissolved in the water increased with NP concentration and was similar for SON and NON-SON solutions. Our results indicate that sonication does not modify toxicity for the copepod A. tonsa. Mean EC{sub 50} values were similar for NON-SON (20.2 mg L{sup −1}) and SON experiments (22.14 mg L{sup −1}) in the acute test. Similarly, no differences occurred between the two different protocols in the semichronic test, with an EC{sub 50} of 7.45 mg L{sup −1} and 6.97 mg L{sup −1} for NON-SON and SON experiments, respectively. Acute and semichronic tests, conducted exposing A. tonsa embryos to NiCl{sub 2} concentrations from 0.025 to 0.63 mg L{sup −1

  16. New Insights in the Ontogeny and Taphonomy of the Devonian Acanthodian Triazeugacanthus affinis From the Miguasha Fossil-Lagerstätte, Eastern Canada

    Directory of Open Access Journals (Sweden)

    Marion Chevrinais

    2015-12-01

    Full Text Available Progressive biomineralization of a skeleton occurs during ontogeny in most animals. In fishes, larvae are poorly mineralized, whereas juveniles and adults display a progressively more biomineralized skeleton. Fossil remains primarily consist of adult specimens because the fossilization of poorly-mineralized larvae and juveniles necessitates exceptional conditions. The Miguasha Fossil-Lagerstätte is renowned for its Late Devonian vertebrate fauna, revealing the exceptional preservation of fossilized ontogenies for 14 of the 20 fish species from this locality. The mineralization of anatomical structures of the acanthodian Triazeugacanthus affinis from Miguasha are compared among larval, juvenile and adult specimens using Energy Dispersive X-ray Spectrometry. Chemical composition of anatomical structures of Triazeugacanthus reveals differences between cartilage and bone. Although the histology and anatomy is well-preserved, Fourier transform infrared spectrometry shows that the original chemical composition of bone is altered by diagenesis; the mineral phase of the bone (i.e., hydroxyapatite is modified chemically to form more stable carbonate-fluorapatite. Fluorination occurring in mineralized skeletal structures of adult Triazeugacanthus is indicative of exchanges between groundwater and skeleton at burial, whereas the preservation of larval soft tissues is likely owing to a rapid burial under anoxic conditions. The exceptional state of preservation of a fossilized ontogeny allowed us to characterize chemically the progressive mineralization of the skeleton in a Devonian early vertebrate.

  17. Effects of a parasitic nematode on male mate choice in a livebearing fish with a coercive mating system (western mosquitofish, Gambusia affinis).

    Science.gov (United States)

    Deaton, Raelynn

    2009-01-01

    I examined the effects of the parasitic larval nematode, Eustrongylides ignotus, on male mate choice in the western mosquitofish, Gambusia affinis. I hypothesized that parasite presence influences male mate choice either directly (via reduction in male mating behavior due to presence of parasite in females) or indirectly (via reduction in male mating behavior due to reduced condition of infected females). Specifically, I tested the predictions that (1) males would mate preferentially with uninfected over infected females (scoring both mating attempts and association time with females); (2) parasitized females would be in poorer condition than non-parasitized females (measured as soluble fat stores); and (3) parasitized females would have reduced fecundity (measured as number of developing embryos). Males preferred to mate with non-parasitized over parasitized females, but showed no differences in association time between females. The nematode did not decrease female body condition, but did decrease female mass, and appeared to decrease female fecundity via reduction in broods (# embryos). Results support that parasites affect male mate choice in mosquitofish; however, the mechanisms used by males to differentiate between parasitized and non-parasitized females remain untested. This study provides the first empirical evidence of parasite affects on male mate choice in livebearing fishes, and suggest a potentially important role for parasite-mediated sexual selection in organisms that use coercive mating as the primary mechanism of obtaining mates.

  18. In-Silico Template Selection of In-Vitro Evolved Kalata B1 of Oldenlandia Affinis for Scaffolding Peptide-Based Drug Design.

    Science.gov (United States)

    Senthilkumar, B; Kumar, Prakash; Rajasekaran, R

    2016-01-01

    Structural stability of Oldenlandia affinis cyclotide, kalata B1 of native (1NB1) and two mutants 2F2I ([P20D, V21K] kB1) and 2F2J ([W19K, P20N, V21K] kB1) was investigated. Single model analysis showed high number of intra-molecular interactions followed by more proportion of beta sheet contents in [P20D, V21K] kB1 as compared to that of native and the other mutant of kalata B1. Further, the modern conformational sampling approach, an alternate to classical molecular dynamics was introduced, which revealed that the [P20D, V21K] kB1 was identified as structurally stable one, substantiated by various structural events viz., root mean square deviation, root mean square fluctuation, and angular deviation by Ramachandran plot. Moreover, the statistically validated contours of polar surface area, hydrogen bond distribution and the distance of disulfide bridges also supported the priority of [P20D, V21K] kB1 with respect to stability. From this work, it is proposed that the [P20D, V21K] kB1 (2F2I) could be the best template for scaffolding peptide based drug design.

  19. Food-web inferences of stable isotope spatial patterns in copepods and yellowfin tuna in the pelagic eastern Pacific Ocean

    Science.gov (United States)

    Olson, Robert J.; Popp, Brian N.; Graham, Brittany S.; López-Ibarra, Gladis A.; Galván-Magaña, Felipe; Lennert-Cody, Cleridy E.; Bocanegra-Castillo, Noemi; Wallsgrove, Natalie J.; Gier, Elizabeth; Alatorre-Ramírez, Vanessa; Ballance, Lisa T.; Fry, Brian

    2010-07-01

    Evaluating the impacts of climate and fishing on oceanic ecosystems requires an improved understanding of the trophodynamics of pelagic food webs. Our approach was to examine broad-scale spatial relationships among the stable N isotope values of copepods and yellowfin tuna ( Thunnus albacares), and to quantify yellowfin tuna trophic status in the food web based on stable-isotope and stomach-contents analyses. Using a generalized additive model fitted to abundance-weighted-average δ 15N values of several omnivorous copepod species, we examined isotopic spatial relationships among yellowfin tuna and copepods. We found a broad-scale, uniform gradient in δ 15N values of copepods increasing from south to north in a region encompassing the eastern Pacific warm pool and parts of several current systems. Over the same region, a similar trend was observed for the δ 15N values in the white muscle of yellowfin tuna caught by the purse-seine fishery, implying limited movement behavior. Assuming the omnivorous copepods represent a proxy for the δ 15N values at the base of the food web, the isotopic difference between these two taxa, “ ΔYFT-COP,” was interpreted as a trophic-position offset. Yellowfin tuna trophic-position estimates based on their bulk δ 15N values were not significantly different than independent estimates based on stomach contents, but are sensitive to errors in the trophic enrichment factor and the trophic position of copepods. An apparent inshore-offshore, east to west gradient in yellowfin tuna trophic position was corroborated using compound-specific isotope analysis of amino acids conducted on a subset of samples. The gradient was not explained by the distribution of yellowfin tuna of different sizes, by seasonal variability at the base of the food web, or by known ambit distances (i.e. movements). Yellowfin tuna stomach contents did not show a regular inshore-offshore gradient in trophic position during 2003-2005, but the trophic

  20. Composition of the zooplankton community, with emphasis in copepods, in Punta Morales, Golfo De Nicoya, Costa Rica.

    Science.gov (United States)

    Brugnoli-Olivera, Ernesto; Díaz-Ferguson, Edgardo; Delfino-Machin, Mariana; Morales-Ramírez, Alvaro; Arosemena, Arturo Dominici

    2004-12-01

    The composition of the mesozooplanktonic community was studied in the Punta Morales estuary, Gulf of Nicoya, Pacific coast of Costa Rica, during 1997. Oblique plankton hauls were performed during high and low tide using a 280 microm mesh screen net equipped with a flowmeter. The community was characterized by holoplanktonic and meroplanktonic organisms. For the holoplanktonic community, the main groups were copepods (80%) and chaetognaths (16%). The most abundant species were the copepods Acartia lilljeborgii and Paracalanus parvus. A. lilljeborgii is a typical estuarine species that maintains high populations in estuarine systems. Meroplankton was represented mainly by crustacean larvae (66%), and icthyoplankton (18%). The dominance of crustacean larvae and icthyoplankton is an evidence of the ecological importance of the Punta Morales zone.

  1. Effect of the copepod parasite Nicothoë astaci on haemolymph chemistry of the European lobster Homarus gammarus.

    Science.gov (United States)

    Davies, Charlotte E; Vogan, Claire L; Rowley, Andrew F

    2015-03-09

    The gills of the European lobster Homarus gammarus (L.) are susceptible to parasitization by the copepod Nicothoë astaci, the lobster louse. This copepod feeds on haemolymph of the host and can damage the gills, potentially affecting gaseous exchange capabilities. To investigate the host response to the parasite, haemolymph levels of total protein, haemocyanin, glucose and ammonia were quantified in adult lobsters carrying varying parasite loads. Parasite loads correlated positively with total haemolymph protein and haemocyanin concentrations but not with glucose or ammonia concentrations. The data suggest that lobsters with gills damaged by the feeding activities of N. astaci respond by producing higher levels of haemocyanin, which is both a key defence response and may compensate for their decreased respiratory functioning.

  2. Effect of bis(tributyltin) oxide on reproduction and population growth rate of calanoid copepod Schmackeria poplesia

    Science.gov (United States)

    Huang, Ying; Zhu, Liyan; Qiu, Xuchun; Zhang, Tianwen

    2010-03-01

    A full life-cycle toxicity test, combined with histology, on calanoid copepod Schmackeria poplesia was used to study the effect of bis(tributyltin) oxide (TBTO). The results indicate no sex-specific differences in TBTO toxicity. Long-term mortalities of the copepods exposed to concentrations higher than 20 ng TBTO L-1 were significantly elevated compared with that of control, and larval development was inhibited when they were exposed to 40 and 60 ng TBTO L-1. The percentages of ovigerous females were reduced compared with the control ( Paborted their egg sacs, 20 ng TBTO L-1 was the only concentration that significantly decreased r m compared with that of control (an effect associated with decreased sex ratio). The results show that the S. poplesia is affected by prolonged exposure to low concentrations of TBTO. The full life-cycle toxicity test combined with histology experiments provides more integral understanding of the toxicity of endocrine disrupters.

  3. Population dynamics and life history strategies of the dominant copepods in a sub-arctic Greenlandic fjord

    DEFF Research Database (Denmark)

    Kjellerup, Sanne; Nielsen, Torkel Gissel

    Investigations of the Arctic and Sub-Arctic pelagic food web have previously focused on the copepod genus Calanus, as they often dominate the mesozooplankton community and serve as a lipid rich food source for higher trophic levels. However, if night samples are considered a different food web...... might emerges with the omnivorous copepod Metridia spp. in a major role. Biology of Metridia is practically unknown but deviates from Calanus e.g. Metridia does not hibernate but stays active yearlong benefiting from being omnivore. In the present study abundance, depth distribution, and egg and pellet...... hibernating Calanus. M. longa might thereby also have a central role in the lipid rich food chain which is a distinct feature for Arctic and Sub-Arctic ecosystems...

  4. Effects of Demersal Otter Trawls on the Re-suspension of Copepod Resting Eggs and its Potential Effects on Recruitment

    DEFF Research Database (Denmark)

    Hansen, Benni Winding; Drillet, Guillaume; Hay, G;

    2014-01-01

    -suspension and the hatching success of copepod resting eggs in the wake of two different demersal fishing gear components (doors and discs) that are in contact with the seabed, in two areas off the coast of Scotland that are rarely worked by fishermen. Sediment cores were taken and analysed for resting eggs quantity......Resting eggs are important phases in the life strategy of many coastal and estuarine copepods. The egg mortality in the sediment layers where they are buried, as well as re-suspension from the sediment into the water column where eggs may hatch are factors that affect the success of this life...... and hatching performance and compared with samples taken in the water column right after re-suspension of sediment by the gear components. This study demonstrated for the first time that although eggs are re-suspended in the water column together with the sediment, providing them with the opportunity to hatch...

  5. Copepods associated with scleractinian corals: a worldwide checklist and a case study of their impact on the reef-building coral Pocillopora damicornis (Linnaeus, 1758) (Pocilloporidae).

    Science.gov (United States)

    Cheng, Yu Rong; Mayfield, Anderson B; Meng, Pei Jie; Dai, Chang Feng; Huys, Rony

    2016-10-11

    The Cnidaria have more symbiotic copepods than any other group of invertebrates, and the greatest numbers of these associates occur on hard corals. A review of the scattered literature on the diversity and taxonomic composition of scleractinian-associated copepods and their hosts revealed a total of 148 coral species, representing 66 genera and 15 families that serve as hosts to copepods. At present, 363 copepod species, representing 99 genera, 19 families and three orders, have been recorded as associates of scleractinian corals. The total included 288 cyclopoids, 68 siphonostomatoids and seven harpacticoids. Within the Cyclopoida the representation of species varied greatly among the 13 families, with a disproportionate number of species belonging to the Anchimolgidae (141 species) and Xarifiidae (92 species). Data on host utilization and geographical distribution of all copepods living symbiotically with hard corals is synthesized and host specificity patterns are highlighted.The prevalence, intensity, density, and biodiversity of copepod infection of 480 colonies of the reef-building coral Pocillopora damicornis (Linnaeus, 1758) from Nanwan Bay, southern Taiwan were documented between July 2007 and November 2008. It was hypothesized that certain environmental factors and physiological coral traits, such as the density of Symbiodinium, could influence these infection parameters. Analysis revealed that ectoparasitic copepods were the most likely to infect P. damicornis, and that Asteropontius minutus Kim, 2003 accounted for more than 50% of total copepod density in July-September 2007 when temperatures were high and bleaching occurred in ~75% of the sampled colonies. The data further showed that copepod virulence may be related to their life history strategies, as well as to Symbiodinium density, surface area of the host coral colonies, and concentration of nitrate and chlorophyll-a in the surrounding seawater. By tracking the abundance, diversity, and

  6. The parasitic dinoflagellates Blastodinium spp. inhabiting the gut of marine, planktonic copepods: morphology, ecology and unrecognized species diversity

    Directory of Open Access Journals (Sweden)

    Alf eSkovgaard

    2012-08-01

    Full Text Available Blastodinium is a genus of dinoflagellates that live as parasites in the gut of marine, planktonic copepods in the World’s oceans and coastal waters. The taxonomy, phylogeny and physiology of the genus has only been explored to a limited degree and, based on recent investigations, we hypothesize that the morphological and genetic diversity within this genus may be considerably larger than presently recognized. To address these issues, we obtained 18S rDNA and ITS gene sequences for Blastodinium specimens of different geographical origins, including representatives of the type species. This genetic information was in some cases complemented with new morphological, ultrastructural, physiological and ecological data. Because most current knowledge about Blastodinium and its effects on copepod hosts stem from publications more than half a century old, we here summarize and discuss the existing knowledge in relation to the new data generated. Most Blastodinium species possess functional chloroplasts, but the parasitic stage, the trophocyte, has etioplasts and probably a limited photosynthetic activity. Sporocytes and swarmer cells have well developed plastids and plausibly acquire part of their organic carbon needs through photosynthesis. A few species are nearly colourless with no functional chloroplasts. The photosynthetic species are almost exclusively found in warm, oligotrophic waters, indicating a life strategy that may benefit from copepods as microhabitats for acquiring nutrients in a nutrient-limited environment. As reported in the literature, monophyly of the genus is moderately supported, but the three main groups proposed by Chatton in 1920 are consistent with molecular data. However, we demonstrate an important genetic diversity within the genus and present evidences for new groups and the presence of cryptic species. Finally, we discuss the current knowledge on the occurrence of Blastodinium spp. and their potential impact on natural

  7. The Parasitic Dinoflagellates Blastodinium spp. Inhabiting the Gut of Marine, Planktonic Copepods: Morphology, Ecology, and Unrecognized Species Diversity

    Science.gov (United States)

    Skovgaard, Alf; Karpov, Sergey A.; Guillou, Laure

    2012-01-01

    Blastodinium is a genus of dinoflagellates that live as parasites in the gut of marine, planktonic copepods in the World’s oceans and coastal waters. The taxonomy, phylogeny, and physiology of the genus have only been explored to a limited degree and, based on recent investigations, we hypothesize that the morphological and genetic diversity within this genus may be considerably larger than presently recognized. To address these issues, we obtained 18S rDNA and ITS gene sequences for Blastodinium specimens of different geographical origins, including representatives of the type species. This genetic information was in some cases complemented with new morphological, ultrastructural, physiological, and ecological data. Because most current knowledge about Blastodinium and its effects on copepod hosts stem from publications more than half a century old, we here summarize and discuss the existing knowledge in relation to the new data generated. Most Blastodinium species possess functional chloroplasts, but the parasitic stage, the trophocyte, has etioplasts and probably a limited photosynthetic activity. Sporocytes and swarmer cells have well-developed plastids and plausibly acquire part of their organic carbon needs through photosynthesis. A few species are nearly colorless with no functional chloroplasts. The photosynthetic species are almost exclusively found in warm, oligotrophic waters, indicating a life strategy that may benefit from copepods as microhabitats for acquiring nutrients in a nutrient-limited environment. As reported in the literature, monophyly of the genus is moderately supported, but the three main groups proposed by Chatton in 1920 are consistent with molecular data. However, we demonstrate an important genetic diversity within the genus and provide evidences for new groups and the presence of cryptic species. Finally, we discuss the current knowledge on the occurrence of Blastodinium spp. and their potential impact on natural copepod

  8. Molecular characterization and expression of vitellogenin (Vg) genes from the cyclopoid copepod, Paracyclopina nana exposed to heavy metals.

    Science.gov (United States)

    Hwang, Dae-Sik; Lee, Kyun-Woo; Han, Jeonghoon; Park, Heum Gi; Lee, Jehee; Lee, Young-Mi; Lee, Jae-Seong

    2010-04-01

    Induction of vitellogenin (Vg) has been used as a biomarker of exposure to heavy metals and endocrine-disruption chemicals (EDCs) in aquatic organisms. Here, we identified the full-length Vg1 and Vg2 sequence from the brackish water copepod, Paracyclopina nana. Vg1 gene contained 5718bp of the open reading frame (ORF) that encoded the putative protein of 1905 amino acids residues, while Vg2 gene consisted of 5442bp of ORF, encoding the putative protein of 1813 amino acids residues. P. nana Vgs showed highly conserved domains in the N-terminal region. The phylogenetic analysis revealed that P. nana Vgs are distinct from other arthropods, such as insects and decapods, as it formed a clade with other copepods, Tigriopus japonicus and salmon louse (Lepeophtheirus salmonis). The expression of Vg transcripts was detectable after the copepodid stages 4-5. Female copepods expressed over 83 times and 223 times more Vg1 and Vg2 transcripts, respectively, than males. When copepods were exposed to heavy metals (0.1mg/L Cd, 0.4mg/L Cu, and 2mg/L AsIII) for 24, 48, 72, and 96h, P. nana Vg transcripts were highly induced in a time-dependent manner. Interestingly, Vg2 gene was more susceptible than Vg1 to trace heavy metal exposure. This finding indicates that P. nana Vgs provide a potential indicator for assessing the toxic effect of heavy metals. In addition, we suggest P. nana as a potential model species for risk-assessment to environmental pollutants in brackish water.

  9. Parasitic outbreak of the copepod Balaenophilus manatorum in neonate loggerhead sea turtles (Caretta caretta) from a head-starting program.

    Science.gov (United States)

    Crespo-Picazo, J L; García-Parraga, D; Domènech, F; Tomás, J; Aznar, F J; Ortega, J; Corpa, J M

    2017-06-02

    Diseases associated to external parasitosis are scarcely reported in sea turtles. During the last decades several organism have been documented as a part of normal epibiont community connected to sea turtles. The copepod Balaenophilus manatorum has been cited as a part of epibiont fauna with some concern about its parasitic capacity. This study serves three purposes, i.e. (i) it sheds light on the type of life style that B. manatorum has developed with its hosts, particularly turtles; (ii) it makes a cautionary note of the potential health risks associated with B. manatorum in sea turtles under captivity conditions and in the wild, and (iii) it provides data on effective treatments against B. manatorum. We report for the first time a massive infestation of the copepod B. manatorum and subsequent acute mortality in a group of loggerhead sea turtle hatchlings. Four-month-old turtles from a head-starting program started exhibiting excitatory and fin rubbing behavior preceding an acute onset of lethargy, skin ulceration and death in some animals. All the individuals (n = 57) were affected by severe copepod load and presented different degrees of external macroscopic skin lesions. The ventral area of front flippers, axillar and pericloacal skin were mostly affected, and were the main parasite distribution regions. Copepods were also detected on plastron and carapace sutures. The gut contents of B. manatorum reacted positively for cytokeratin, indicating consumption of turtle skin. Severe ulcerative necrotic dermatitis and large amount of bacteria presence were the major histopathological findings. Individual fresh water immersion for 10 min and lufenuron administration (0.1 ppm) to the water system every 2 weeks proved effective for removing turtle parasites and to control re-infestation, respectively. The results from our study clearly indicated that B. manatorum individuals consume turtle skin. The pathological effects of this agent and the potential implications

  10. Nuclear and mitochondrial gene genealogies and allozyme polymorphism across a major phylogeographic break in the copepod Tigriopus californicus.

    OpenAIRE

    Burton, R S; Lee, B. N.

    1994-01-01

    The genetic structure of natural populations is frequently inferred from geographic distributions of alleles at multiple gene loci. Surveys of allozyme polymorphisms in the tidepool copepod Tigriopus californicus have revealed sharp genetic differentiation of populations, indicating that gene flow among populations is highly restricted. Analysis of population structure in this species has now been extended to include nuclear and mitochondrial gene genealogies. DNA sequences of the mtDNA-encod...

  11. Sensitivity to ocean acidification parallels natural pCO2 gradients experienced by Arctic copepods under winter sea ice.

    Science.gov (United States)

    Lewis, Ceri N; Brown, Kristina A; Edwards, Laura A; Cooper, Glenn; Findlay, Helen S

    2013-12-17

    The Arctic Ocean already experiences areas of low pH and high CO2, and it is expected to be most rapidly affected by future ocean acidification (OA). Copepods comprise the dominant Arctic zooplankton; hence, their responses to OA have important implications for Arctic ecosystems, yet there is little data on their current under-ice winter ecology on which to base future monitoring or make predictions about climate-induced change. Here, we report results from Arctic under-ice investigations of copepod natural distributions associated with late-winter carbonate chemistry environmental data and their response to manipulated pCO2 conditions (OA exposures). Our data reveal that species and life stage sensitivities to manipulated OA conditions were correlated with their vertical migration behavior and with their natural exposures to different pCO2 ranges. Vertically migrating adult Calanus spp. crossed a pCO2 range of >140 μatm daily and showed only minor responses to manipulated high CO2. Oithona similis, which remained in the surface waters and experienced a pCO2 range of <75 μatm, showed significantly reduced adult and nauplii survival in high CO2 experiments. These results support the relatively untested hypothesis that the natural range of pCO2 experienced by an organism determines its sensitivity to future OA and highlight that the globally important copepod species, Oithona spp., may be more sensitive to future high pCO2 conditions compared with the more widely studied larger copepods.

  12. Influence of a cage farming on the population of the fish species Apareiodon affinis (Steindachner, 1879 in the Chavantes reservoir, Paranapanema River SP/PR, Brazil Influência de uma piscicultura em tanques-rede na população da espécie de peixe Apareiodon affinis (Steindachner, 1879 no reservatório de Chavantes, rio Paranapanema SP/PR, Brasil

    Directory of Open Access Journals (Sweden)

    Heleno Brandão

    2012-12-01

    Full Text Available AIM: The aim of the present study was to evaluate the diet and biological attributes of the population of Apareiodon affinis residing near net-cage fish farming activities in the Chavantes reservoir. METHODS: Samples were collected from two populations: one near the net cages (NC and one from an area not influenced by these cages denominated the "reference site" (RS. Monthly sampling was carried out from Mar/2008 to Feb/2009. Fish were caught with a standardized effort using gill nets deployed for 14 hours. After all individuals were measured (standard length and weighed (total weight, carcass weight , body weight without gonads. To determine the composition of the diet, the alimentary index was calculated (AI. We also calculated the length-weight relationship, condition factor, gonad-somatic index (GSI and reproductive potential. RESULTS: A total of 3050 individuals were caught. The results of the (AI revealed that the item detritus was the main food used for populations of A. affinis studied in two areas (NC = 73.1% and RS = 95.7%. The use of feed on diet A. affinis was recorded for the populations of NC adding (20.5% of the total items consumed by the population. The resident populations residing near net-cage showed higher condition factor and more reproductive period. CONCLUSIONS: The results show the ability of the species to benefit from the input of organic matter from fish farming activities, inserting a new item in their diet (ration. This work indicates that the species A. affinis managed to establish near net-cage, allocating enough energy to increase their reproductive period and maintain viable populations close to net-cage, evidenced by the high abundance. This study suggests that systems of fish farming in net-cage influence diet and biological attributes of the species A. affinis residents Chavantes reservoir, Brazil.OBJETIVO: O objetivo deste estudo foi avaliar a influência de uma piscicultura em tanques-rede na dieta e nos

  13. Response of antioxidant defense system in copepodCalanus sinicus Brodsky exposed to CO2-acidified seawater

    Institute of Scientific and Technical Information of China (English)

    ZHANG Dajuan; GUO Donghui; WANG Guizhong; LI Shaojing

    2016-01-01

    Marine zooplankton responds sensitively to elevated seawater CO2 concentration. However, the underlying physiological mechanisms have not been studied well. We therefore investigated the effects of elevated CO2 concentration (0.08%, 0.20%, 0.50% and 1.00%) on antioxidant defense components, as well as two detoxification enzymes ofCalanus sinicus (copepod). The results showed that glutathione peroxidase (GPx) activity exposed to CO2-acidified seawater was significantly stimulated while other antioxidant components, including glutathione-S-transferase (GST) activity, superoxide dismutase (SOD) activity decreased significantly with reduced glutathione (GSH) level and GSH/oxidized glutathione (GSSG) value. CO2-acidified seawater exhibited stimulatory effects on adenosine triphosphatase (ATPase) activity and acetylcholinesterase (AchE) activity was inhibited. Moreover, the results of principal component analysis indicated that 75.93% of the overall variance was explained by the first two principal components. The elevated CO2 concentration may affect the metabolism and survivals of copepods through impacts these enzymes activities. Further studies are needed to focus on the synergistic effects of elevated CO2 concentration and other environmental factors on copepods.

  14. Overlooked cryptic endemism in copepods: systematics and natural history of the calanoid subgenus Occidodiaptomus Borutzky 1991 (Copepoda, Calanoida, Diaptomidae).

    Science.gov (United States)

    Marrone, Federico; Lo Brutto, Sabrina; Hundsdoerfer, Anna K; Arculeo, Marco

    2013-01-01

    Our comprehension of the phylogeny and diversity of most inland-water crustaceans is currently hampered by their pronounced morphological bradytely, which contributed to the affirmation of the "Cosmopolitanism Paradigm" of freshwater taxa. However, growing evidence of the existence of cryptic diversity and molecular regionalism is available for calanoid copepods, thus stressing the need for careful morphological and molecular studies in order to soundly investigate the systematics, diversity and distribution patterns of the group. Diaptomid copepods were here chosen as model taxa, and the morphological and molecular diversity of the species belonging to the west-Mediterranean diaptomid subgenus Occidodiaptomus were investigated with the aim of comparing the patterns of morphological and molecular evolution in freshwater copepods. Three species currently lumped under the binomen Hemidiaptomus (Occidodiaptomus) ingens and two highly divergent clades within H. (O.) roubaui were distinguished, thus showing an apparent discordance between the molecular distances recorded and Occidodiaptomus morphological homogeneity, and highlighting a noteworthy decoupling between the morphological and molecular diversity in the subgenus. Current Occidodiaptomus diversity pattern is ascribed to a combined effect of ancient vicariance and recent dispersal events. It is stressed that the lack of sound calibration points for the molecular clock makes it difficult to soundly temporally frame the diversification events of interest in the taxon studied, and thus to asses the role of morphological bradytely and of accelerated molecular evolutionary rates in shaping the current diversity of the group. Copyright © 2012 Elsevier Inc. All rights reserved.

  15. Acute toxicity of dispersed crude oil on the cold-water copepod Calanus finmarchicus: Elusive implications of lipid content.

    Science.gov (United States)

    Hansen, Bjørn Henrik; Jager, Tjalling; Altin, Dag; Øverjordet, Ida B; Olsen, Anders J; Salaberria, Iurgi; Nordtug, Trond

    2016-01-01

    In this investigation, acute toxicity data were used from two previously reported studies where cold-water copepods were exposed to mechanically dispersed (MD) and chemically (CD) dispersed oil. In one of these studies, concentration-dependent mortality was observed, whereas no apparent relationship between exposure concentration and mortality was found in the other. The only marked difference between the studies is that copepods in the first experiment displayed a lower lipid sac volume (on average) than in the second one. In this study additional biometric data on lipid content were utilized and observed effects and toxicokinetics modeling applied in order to investigate whether differences in sensitivity between copepod cohorts might be explained by differences in lipid content. Results suggest that although a considerable lipid sac might retard toxicokinetics, the observed differences in lipid volume are not sufficient to explain differences in toxicity. Further, there are no apparent indications that acute toxic stress leads to lipid depletion, or that acute increased mortality rate selectively affects lipid-poor individuals. It is conceivable that other potential explanations exist, but the causal relationship between lipid content and increased mortality frequency remains elusive.

  16. Identification and molecular characterization of dorsal and dorsal-like genes in the cyclopoid copepod Paracyclopina nana.

    Science.gov (United States)

    Jeong, Chang-Bum; Lee, Min Chul; Lee, Kyun-Woo; Seo, Jung Soo; Park, Heum Gi; Rhee, Jae-Sung; Lee, Jae-Seong

    2015-12-01

    To date, knowledge of the immune system in aquatic invertebrates has been reported in only a few model organisms, even though all metazoans have an innate immune system. In particular, information on the copepod's immunity and the potential role of key genes in the innate immune systems is still unclear. In this study, we identified dorsal and dorsal-like genes in the cyclopoid copepod Paracyclopina nana. In silico analyses for identifying conserved domains and phylogenetic relationships supported their gene annotations. The transcriptional levels of both genes were slightly increased from the nauplius to copepodid stages, suggesting that these genes are putatively involved in copepodid development of P. nana. To examine the involvement of both genes in the innate immune response and under stressful conditions, the copepods were exposed to lipopolysaccharide (LPS), different culture densities, salinities, and temperatures. LPS significantly upregulated mRNA expressions of dorsal and dorsal-like genes, suggesting that both genes are transcriptionally sensitive in response to immune modulators. Exposure to unfavorable culture conditions also increased mRNA levels of dorsal and dorsal-like genes. These findings suggest that transcriptional regulation of the dorsal and dorsal-like genes would be associated with environmental changes in P. nana.

  17. The metabolic response of marine copepods to environmental warming and ocean acidification in the absence of food

    Science.gov (United States)

    Mayor, Daniel J.; Sommer, Ulf; Cook, Kathryn B.; Viant, Mark R.

    2015-09-01

    Marine copepods are central to the productivity and biogeochemistry of marine ecosystems. Nevertheless, the direct and indirect effects of climate change on their metabolic functioning remain poorly understood. Here, we use metabolomics, the unbiased study of multiple low molecular weight organic metabolites, to examine how the physiology of Calanus spp. is affected by end-of-century global warming and ocean acidification scenarios. We report that the physiological stresses associated with incubation without food over a 5-day period greatly exceed those caused directly by seawater temperature or pH perturbations. This highlights the need to contextualise the results of climate change experiments by comparison to other, naturally occurring stressors such as food deprivation, which is being exacerbated by global warming. Protein and lipid metabolism were up-regulated in the food-deprived animals, with a novel class of taurine-containing lipids and the essential polyunsaturated fatty acids (PUFAs), eicosapentaenoic acid and docosahexaenoic acid, changing significantly over the duration of our experiment. Copepods derive these PUFAs by ingesting diatoms and flagellated microplankton respectively. Climate-driven changes in the productivity, phenology and composition of microplankton communities, and hence the availability of these fatty acids, therefore have the potential to influence the ability of copepods to survive starvation and other environmental stressors.

  18. The toxicity of the three antifouling biocides DCOIT, TPBP and medetomidine to the marine pelagic copepod Acartia tonsa.

    Science.gov (United States)

    Wendt, Ida; Backhaus, Thomas; Blanck, Hans; Arrhenius, Åsa

    2016-07-01

    Copepods, the largest group of pelagic grazers, are at risk from exposure to antifouling biocides. This study investigated the toxicity of the antifouling biocides 4,5-dichloro-2-octyl-1,2-thiazol-3(2H)-one (DCOIT), triphenylborane pyridine (TPBP) and 4-[1-(2,3-dimethylphenyl)ethyl]-1H-imidazole (medetomidine) to the copepod Acartia tonsa, using mortality and egg production as endpoints. The toxicity ranking for mortality was as follows: DCOIT (LC50 57 nmol l(-1)) = TPBP (LC50 56 nmol l(-1)) > medetomidine (LC50 241 nmol l(-1)). Egg production was more sensitive than mortality to TPBP (EC50 3.2 nmol l(-1)), while DCOIT and medetomidine inhibited egg production at roughly the same concentrations (72 and 186 nmol l(-1) respectively). Furthermore, TPBP seems to affect egg hatching directly which was not the case for DCOIT and medetomidine. DCOIT and medetomidine might pose an environmental risk as they have been reported to occur in different exposure scenarios or analytical surveys at concentrations only 2-3 times lower than the respective EC10. Reported environmental concentrations of TPBP are few but clearly lower than the EC10 values reported here, suggesting current risk of TPBP to copepods to be moderate.

  19. The minute brain of the copepod Tigriopus californicus supports a complex ancestral ground pattern of the tetraconate cerebral nervous systems.

    Science.gov (United States)

    Andrew, David R; Brown, Sheena M; Strausfeld, Nicholas J

    2012-10-15

    Copepods are a diverse and ecologically crucial group of minute crustaceans that are relatively neglected in terms of studies on nervous system organization. Recently, morphological neural characters have helped clarify evolutionary relationships within Arthropoda, particularly among Tetraconata (i.e., crustaceans and hexapods), and indicate that copepods occupy an important phylogenetic position relating to both Malacostraca and Hexapoda. This taxon therefore provides the opportunity to evaluate those neural characters common to these two clades likely to be results of shared ancestry (homology) versus convergence (homoplasy). Here we present an anatomical characterization of the brain and central nervous system of the well-studied harpacticoid copepod species Tigriopus californicus. We show that this species is endowed with a complex brain possessing a central complex comprising a protocerebral bridge and central body. Deutocerebral glomeruli are supplied by the antennular nerves, and a lateral protocerebral olfactory neuropil corresponds to the malacostracan hemiellipsoid body. Glomeruli contain synaptic specializations comparable to the presynaptic "T-bars" typical of dipterous insects, including Drosophila melanogaster. Serotonin-like immunoreactivity pervades the brain and ventral nervous system, with distinctive deutocerebral distributions. The present observations suggest that a suite of morphological characters typifying the Tigriopus brain reflect a ground pattern organization of an ancestral Tetraconata, which possessed an elaborate and structurally differentiated nervous system.

  20. Epipelagic copepod distributions in the eastern equatorial Pacific during the weak La Niña event of 2001

    Directory of Open Access Journals (Sweden)

    Pritha Tutasi

    2011-07-01

    Full Text Available We determined the distribution and abundance of pelagic copepods in the eastern equatorial Pacific between the coast of Ecuador and the Galapagos Islands under oceanographic conditions associated with the weak La Niña event of 2001. In September-October 2001, negative anomalies of sea surface temperature from this event still remained in the eastern equatorial Pacific, mainly between Ecuador and the Galapagos Islands. The event allowed the incursion of the Humboldt Current farther north and of the Equatorial Undercurrent into the study area, favouring a strong Equatorial Front and upwelling processes. There was evidence of mesoscale eddies in the study area and of the presence of the South Equatorial Current going westward at about 1°N. We identified 107 copepod species and analyzed the distribution of the 10 most abundant ones: Oncaea venusta, Subeucalanus pileatus, S. crassus, S. subtenuis, Paraeucalanus attenuatus, Pleuromamma borealis, Scolecithrix danae, Clausocalanus farrani, Temora discaudata and Calanus chilensis. Copepod distribution and abundance exhibited marked latitudinal differences related to the oceanographic conditions; abundance was highest to the southeast of the Galapagos Islands. Oncaea venusta, Pleuromamma borealis, Calanus chilensis, and Subeucalanus subtenuis were the species that best defined the Equatorial Front and the upwelling process.

  1. Copepods enhance nutritional status, growth and development in Atlantic cod (Gadus morhua L. larvae — can we identify the underlying factors?

    Directory of Open Access Journals (Sweden)

    Ørjan Karlsen

    2015-05-01

    Full Text Available The current commercial production protocols for Atlantic cod depend on enriched rotifers and Artemia during first-feeding, but development and growth remain inferior to fish fed natural zooplankton. Two experiments were conducted in order to identify the underlying factors for this phenomenon. In the first experiment (Exp-1, groups of cod larvae were fed either (a natural zooplankton, mainly copepods, increasing the size of prey as the larvae grew or (b enriched rotifers followed by Artemia (the intensive group. In the second experiment (Exp-2, two groups of larvae were fed as in Exp-1, while a third group was fed copepod nauplii (approximately the size of rotifers throughout the larval stage. In both experiments, growth was not significantly different between the groups during the first three weeks after hatching, but from the last part of the rotifer feeding period and onwards, the growth of the larvae fed copepods was higher than that of the intensive group. In Exp-2, the growth was similar between the two copepod groups during the expeimental period, indicating that nutrient composition, not prey size caused the better growth on copepods. Analyses of the prey showed that total fatty acid composition and the ratio of phospholipids to total lipids was slightly different in the prey organisms, and that protein, taurine, astaxanthin and zinc were lower on a dry weight basis in rotifers than in copepods. Other measured nutrients as DHA, all analysed vitamins, manganese, copper and selenium were similar or higher in the rotifers. When compared to the present knowledge on nutrient requirements, protein and taurine appeared to be the most likely limiting nutrients for growth in cod larvae fed rotifers and Artemia. Larvae fed rotifers/Artemia had a higher whole body lipid content than larvae fed copepods at the end of the experiment (stage 5 after the fish had been fed the same formulated diet for approximately 2 weeks.

  2. 食蚊鱼对水生昆虫的捕食选择性研究%Predacious Selection of Gambusia affinis on Aquatic Insects

    Institute of Scientific and Technical Information of China (English)

    刘丽娟; 童晓立

    2012-01-01

    To investigate the effects of mosquitofish, Gambusia affinis on aquatic insect biodiversity in South China, three common species of aquatic insects in mosquitofish habitat, I. E. , Cloeon bengalense, Chironomus kiiensis and Aedes albopictus, were selected under the lab condition to test the feeding preference of mosquitofish. The resulted showed that mosquitofish had no significant feeding selection on all preys in low density under the single-predator-and-multiple-preys experimental design. But mosquitofish preferred the larvae and pupa of A. Albopictus to other preys with the increase of prey density. When the prey ratio was 1' 1 under the single-predator-and-two-prey experimental design, mosquitofish frequently prefer larvae of A. Albopictus to the other prey. However, there was no significant influence to total prey consumption for mosquitofish when prey ratio was changed but total prey numbers unchanged. The results suggested that G. Affinis preferred to feed on the mobile prey close to water surface and showed no interest in the unmoving or dead prey, and mosquito larvae were the favorite prey of mosquitofish compared with mayflies and chironomids.%为了解食蚊鱼Gambusia affinis对华南地区水生昆虫多样性的影响,在实验室条件下,以食蚊鱼栖境中有代表性的3种水生昆虫为猎物,研究食蚊鱼的捕食选择性.结果表明,在单捕食者-多种猎物作用系统中,当猎物密度较低时,食蚊鱼对不同猎物的捕食选择性差异不显著.但随猎物密度的增加,食蚊鱼对白纹伊蚊Aedesalbopictus幼虫和蛹的捕食量明显增加,对摇蚊Chironomus kiiensis幼虫和蜉蝣Cloeon bengalense稚虫的捕食量下降.在单捕食者-2种猎物的作用系统中,在猎物比例相同的情况下,食蚊鱼更喜欢捕食白纹伊蚊幼虫;但是在猎物总数不变的情况下,改变猎物比例,对食蚊鱼总的捕食量影响不大.说明食蚊鱼喜欢捕食漂浮于水面上、会动的活体猎物,对

  3. Heads or tails: do stranded fish (mosquitofish, Gambusia affinis know where they are on a slope and how to return to the water?

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    Robert J Boumis

    Full Text Available Aquatic vertebrates that emerge onto land to spawn, feed, or evade aquatic predators must return to the water to avoid dehydration or asphyxiation. How do such aquatic organisms determine their location on land? Do particular behaviors facilitate a safe return to the aquatic realm? In this study, we asked: will fully-aquatic mosquitofish (Gambusia affinis stranded on a slope modulate locomotor behavior according to body position to facilitate movement back into the water? To address this question, mosquitofish (n = 53 were placed in four positions relative to an artificial slope (30° inclination and their responses to stranding were recorded, categorized, and quantified. We found that mosquitofish may remain immobile for up to three minutes after being stranded and then initiate either a "roll" or a "leap". During a roll, mass is destabilized to trigger a downslope tumble; during a leap, the fish jumps up, above the substrate. When mosquitofish are oriented with the long axis of the body at 90° to the slope, they almost always (97% initiate a roll. A roll is an energetically inexpensive way to move back into the water from a cross-slope body orientation because potential energy is converted back into kinetic energy. When placed with their heads toward the apex of the slope, most mosquitofish (>50% produce a tail-flip jump to leap into ballistic flight. Because a tail-flip generates a caudually-oriented flight trajectory, this locomotor movement will effectively propel a fish downhill when the head is oriented up-slope. However, because the mass of the body is elevated against gravity, leaps require more mechanical work than rolls. We suggest that mosquitofish use the otolith-vestibular system to sense body position and generate a behavior that is "matched" to their orientation on a slope, thereby increasing the probability of a safe return to the water, relative to the energy expended.

  4. Coal ash basin effects (particulates, metals, acidic pH) upon aquatic biota: an eight-year evaluation. [Gambusia affinis; Plathemis lydia; Libellula spp

    Energy Technology Data Exchange (ETDEWEB)

    Cerry, D.S.; Guthrie, R.K.; Davis, E.M.; Harvey, R.S.

    1984-08-01

    Coal ash effluent effects including particulates, acidic pH excursions, elemental concentrations and bioconcentration in selected organisms have been studied as changes in water quality and densities of benthic macroinvertebrate and mosquitofish (Gambusia affinis) populations in a swanmp drainage system over an eight-year period. Initial density of the aquatic biota was altered severely by heavy ash siltation, followed by acidic pH excursions, and perhaps overall by elemental concentrations and bioaccumulation. Heavy ash siltation, followed by acidic pH excursions after the addition of fly ash to the original settling basin system, had the most profound effect on biota. Dipterans (chironomids) and some odonates (Plathemis lydia and Libellula spp.) were resistant to heavy ash siltation, while mosquitofish, which showed no discernible responses to ash siltation, were absent at acidic pH along with the few previously surviving invertebrate populations. Elemental concentrations of arsenic, cadmium, chromium, copper, selenium, and zinc did not appear to limit aquatic flora and fauna on a short-term, acute basis. Long-chronic elemental exposures may have been instrumental in retarding the recovery of all forms of aquatic life in the receiving system. Elemental concentrations (except for arsenic and selenium) in the receiving system were generally one to two orders of magnitude higher than the Water Quality Criteria set by the US Environmental Protection Agency (1980) for protection of aquatic life for the minimum and 24-hour mean values. By 1978, when the new settling basin systems were operating effectively, invertebrate populations were largely recovered, and mosquito-fish populations recovered within one year afterward.

  5. Feeding strategies of tropical and subtropical calanoid copepods throughout the eastern Atlantic Ocean - Latitudinal and bathymetric aspects

    Science.gov (United States)

    Bode, Maya; Hagen, Wilhelm; Schukat, Anna; Teuber, Lena; Fonseca-Batista, Debany; Dehairs, Frank; Auel, Holger

    2015-11-01

    The majority of global ocean production and total export production is attributed to oligotrophic oceanic regions due to their vast regional expanse. However, energy transfers, food-web structures and trophic relationships in these areas remain largely unknown. Regional and vertical inter- and intra-specific differences in trophic interactions and dietary preferences of calanoid copepods were investigated in four different regions in the open eastern Atlantic Ocean (38°N to 21°S) in October/November 2012 using a combination of fatty acid (FA) and stable isotope (SI) analyses. Mean carnivory indices (CI) based on FA trophic markers generally agreed with trophic positions (TP) derived from δ15N analysis. Most copepods were classified as omnivorous (CI ∼0.5, TP 1.8 to ∼2.5) or carnivorous (CI ⩾ 0.7, TP ⩾ 2.9). Herbivorous copepods showed typical CIs of ⩽0.3. Geographical differences in δ15N values of epi- (200-0 m) to mesopelagic (1000-200 m) copepods reflected corresponding spatial differences in baseline δ15N of particulate organic matter from the upper 100 m. In contrast, species restricted to lower meso- and bathypelagic (2000-1000 m) layers did not show this regional trend. FA compositions were species-specific without distinct intra-specific vertical or spatial variations. Differences were only observed in the southernmost region influenced by the highly productive Benguela Current. Apparently, food availability and dietary composition were widely homogeneous throughout the mesotrophic oceanic regions of the tropical and subtropical Atlantic. Four major species clusters were identified by principal component analysis based on FA compositions. Vertically migrating species clustered with epi- to mesopelagic, non-migrating species, of which only Neocalanus gracilis was moderately enriched in lipids with 16% of dry mass (DM) and stored wax esters (WE) with 37% of total lipid (TL). All other species of this cluster had low lipid contents (deep

  6. Short-term changes of the mesozooplankton community and copepod gut pigment in the Chukchi Sea in autumn

    Science.gov (United States)

    Matsuno, K.; Yamaguchi, A.; Nishino, S.; Inoue, J.; Kikuchi, T.

    2015-03-01

    In the Chukchi Sea, due to the recent drastic reduction of sea-ice during the summer, an increasing formation of atmospheric turbulence has been reported. However, the importance and effects of atmospheric turbulence on the marine ecosystem are not fully understood in this region. To evaluate the effect of atmospheric turbulence on the marine ecosystem, high-frequent sampling (two to four times per day) on the mesozooplankton community and the gut pigment of dominant copepods were made at a fixed station in the Chukchi Sea from 10 to 25 September 2013. During the study period, a strong wind event (SWE) was observed on 18 September. After the SWE, the standing stock of chlorophyll a (chl a) was increased, especially for micro-size (> 10 μm) fractions. Zooplankton abundance ranged 23 610-56 809 ind. m-2 and exhibited no clear changes with SWE. In terms of abundance, calanoid copepods constituted the most dominated taxa (mean: 57%), followed by barnacle larvae (31%). Within the calanoid copepods, small-sized Pseudocalanus spp. (65%) and large-sized Calanus glacialis (30%) dominated. In the population structure of C. glacialis, copepodid stage 5 (C5) dominated, and the mean copepodid stage did not vary with SWE. The dominance of accumulated lipids in C5 and C6 females with immature gonads indicated that they were preparing for seasonal diapause. The gut pigment of C. glacialis C5 was higher at night and was correlated with ambient chl a, and a significant increase was observed after SWE (2.6 vs. 4.5 ng pigment ind.-1). Assuming C : Chl a ratio, the grazing impact by C. glacialis C5 was estimated to be 4.14 mg C m-2 day-1, which corresponded to 0.5-4.6% of the standing stock of micro-size phytoplankton. Compared with the metabolic food requirement, their feeding on phytoplankton accounted for 12.6% of their total food requirement. These facts suggest that C. glacialis could not maintain their population on solely phytoplankton food, and other food sources (i

  7. Spliced leader-based analyses reveal the effects of polycyclic aromatic hydrocarbons on gene expression in the copepod Pseudodiaptomus poplesia.

    Science.gov (United States)

    Zhuang, Yunyun; Yang, Feifei; Xu, Donghui; Chen, Hongju; Zhang, Huan; Liu, Guangxing

    2017-02-01

    Polycyclic aromatic hydrocarbons (PAHs) are a group of toxic and carcinogenic pollutants that can adversely affect the development, growth and reproduction of marine organisms including copepods. However, knowledge on the molecular mechanisms regulating the response to PAH exposure in marine planktonic copepods is limited. In this study, we investigated the survival and gene expression of the calanoid copepod Pseudodiaptomus poplesia upon exposure to two PAHs, 1, 2-dimethylnaphthalene (1, 2-NAPH) and pyrene. Acute toxicity responses resulted in 96-h LC50 of 788.98μgL(-1) and 54.68μgL(-1) for 1, 2-NAPH and pyrene, respectively. Using the recently discovered copepod spliced leader as a primer, we constructed full-length cDNA libraries from copepods exposed to sublethal concentrations and revealed 289 unique genes of diverse functions, including stress response genes and novel genes previously undocumented for this species. Eighty-three gene families were specifically expressed in PAH exposure libraries. We further analyzed the expression of seven target genes by reverse transcription-quantitative PCR in a time-course test with three sublethal concentrations. These target genes have primary roles in detoxification, oxidative defense, and signal transduction, and include different forms of glutathione S-transferase (GST), glutathione peroxidases (GPX), peroxiredoxin (PRDX), methylmalonate-semialdehyde dehydrogenase (MSDH) and ras-related C3 botulinum toxin substrate (RAC1). Expression stability of seven candidate reference genes were evaluated and the two most stable ones (RPL15 and RPS20 for 1, 2-NAPH exposure, RPL15 and EF1D for pyrene exposure) were used to normalize the expression levels of the target genes. Significant upregulation was detected in GST-T, GST-DE, GPX4, PRDX6 and RAC1 upon 1, 2-NAPH exposure, and GST-DE and MSDH upon pyrene exposure. These results indicated that the oxidative stress was induced and that signal transduction might be affected by PAH

  8. Copepod colonization of organic and inorganic substrata at a deep-sea hydrothermal vent site on the Mid-Atlantic Ridge

    Science.gov (United States)

    Plum, Christoph; Pradillon, Florence; Fujiwara, Yoshihiro; Sarrazin, Jozée

    2017-03-01

    The few existing studies on deep-sea hydrothermal vent copepods indicate low connectivity with surrounding environments and reveal high endemism among vents. However, the finding of non-endemic copepod species in association with engineer species at different reduced ecosystems poses questions about the dispersal of copepods and the colonization of hydrothermal vents as well as their ecological connectivity. The objective of this study is to understand copepod colonization patterns at a hydrothermal vent site in response to environmental factors such as temperature and fluid flow as well as the presence of different types of substrata. To address this objective, an in situ experiment was deployed using both organic (woods, pig bones) and inorganic (slates) substrata along a gradient of hydrothermal activity at the Lucky Strike vent field (Eiffel Tower, Mid-Atlantic Ridge). The substrata were deployed in 2011 during the MoMARSAT cruise and were recovered after two years in 2013. Overall, copepod density showed significant differences between substrata types, but was similar among different hydrothermal activity regimes. Highest densities were observed on woods at sites with moderate or low fluid input, whereas bones were the most densely colonized substrata at the 2 sites with higher hydrothermal influence. Although differences in copepod diversity were not significant, the observed trends revealed overall increasing diversity with decreasing temperature and fluid input. Slates showed highest diversity compared to the organic substrata. Temperature and fluid input had a significant influence on copepod community composition, resulting in higher similarity among stations with relatively high and low fluid inputs, respectively. While vent-specialists such as dirivultids and the tegastid Smacigastes micheli dominated substrata at high vent activity, the experiment demonstrated increasing abundance and dominance of non-vent taxa with decreasing temperature and fluid

  9. Zooplankton community structure and copepod species composition in the northern Gulf of Mexico

    Science.gov (United States)

    Ortner, Peter B.; Hill, Leonard C.; Cummings, Shailer R.

    1989-04-01

    Zooplankton community structure and copepod species composition are analysed in samples obtained during spring and winter from three areas of the northern Gulf of Mexico: near the Mississippi River outflow, off Cape San Blas, and in the central Gulf of Mexico. Samples from different regions were distinguishable in correspondence analysis of dominant species and/or functional groups. The near-surface communities of the Mississippi and central Gulf were particularly distinct while Cape San Blas was intermediate in both structure and specific character. Saltier waters directly beneath the Mississippi Plume yielded samples similar to those from near-surface waters well offshore. At the same time near-surface waters off the Mississippi and off Cape San Blass to the west were distinguishable even during spring when the outflow from the Mississippi was at its annual peak. These differences are consistent with the discharge and flow patterns of the Mississippi River plume and the northern Gulf and with systematic differences in such parameters as temperature, salinity and chlorophyll concentration. The implications of these observations upon the feeding environments of the larvae of commercially significant fish species are addressed since both zooplankton prey and larval predators appear to be particularly abundant in the Mississippi River plume environs.

  10. Elevated oxidative damage is correlated with reduced fitness in interpopulation hybrids of a marine copepod.

    Science.gov (United States)

    Barreto, Felipe S; Burton, Ronald S

    2013-09-22

    Aerobic energy production occurs via the oxidative phosphorylation pathway (OXPHOS), which is critically dependent on interactions between the 13 mitochondrial DNA (mtDNA)-encoded and approximately 70 nuclear-encoded protein subunits. Disruptive mutations in any component of OXPHOS can result in impaired ATP production and exacerbated oxidative stress; in mammalian systems, such mutations are associated with ageing as well as numerous diseases. Recent studies have suggested that oxidative stress plays a role in fitness trade-offs in life-history evolution and functional ecology. Here, we show that outcrossing between populations with divergent mtDNA can exacerbate cellular oxidative stress in hybrid offspring. In the copepod Tigriopus californicus, we found that hybrids that showed evidence of fitness breakdown (low fecundity) also exhibited elevated levels of oxidative damage to DNA, whereas those with no clear breakdown did not show significantly elevated damage. The extent of oxidative stress in hybrids appears to be dependent on the degree of genetic divergence between their respective parental populations, but this pattern requires further testing using multiple crosses at different levels of divergence. Given previous evidence in T. californicus that hybridization disrupts nuclear/mitochondrial interactions and reduces hybrid fitness, our results suggest that such negative intergenomic epistasis may also increase the production of damaging cellular oxidants; consequently, mtDNA evolution may play a significant role in generating postzygotic isolating barriers among diverging populations.

  11. Fitness and morphological outcomes of many generations of hybridization in the copepod Tigriopus californicus.

    Science.gov (United States)

    Pritchard, V L; Knutson, V L; Lee, M; Zieba, J; Edmands, S

    2013-02-01

    Hybridization between genetically divergent populations is an important evolutionary process, with an outcome that is difficult to predict. We used controlled crosses and freely mating hybrid swarms, followed for up to 30 generations, to examine the morphological and fitness consequences of interpopulation hybridization in the copepod Tigriopus californicus. Patterns of fitness in two generations of controlled crosses were partly predictive of long-term trajectories in hybrid swarms. For one pair of populations, controlled crosses revealed neutral or beneficial effects of hybridization after the F1 generation, and hybrid swarm fitness almost always equalled or exceeded that of the midparent. For a second pair, controlled crosses showed F2 hybrid breakdown, but increased fitness in backcrosses, and hybrid swarm fitness deviated both above and below that of the parentals. Nevertheless, individual swarm replicates exhibited different fitness trajectories over time that were not related in a simple manner to their hybrid genetic composition, and fixation of fitter hybrid phenotypes was not observed. Hybridization did not increase overall morphological variation, and underlying genetic changes may have been masked by phenotypic plasticity. Nevertheless, one type of hybrid swarm exhibited a repeatable pattern of transgressively large eggsacs, indicating a positive effect of hybridization on individual fecundity. Additionally, both parental and hybrid swarms exhibited common phenotypic trends over time, indicating common selective pressures in the laboratory environment. Our results suggest that, in a system where much work has focused on F2 hybrid breakdown, the long-term fitness consequences of interpopulation hybridization are surprisingly benign.

  12. No evidence for faster male hybrid sterility in population crosses of an intertidal copepod (Tigriopus californicus).

    Science.gov (United States)

    Willett, Christopher S

    2008-06-01

    Two different forces are thought to contribute to the rapid accumulation of hybrid male sterility that has been observed in many inter-specific crosses, namely the faster male and the dominance theories. For male heterogametic taxa, both faster male and dominance would work in the same direction to cause the rapid evolution of male sterility; however, for taxa lacking differentiated sex chromosomes only the faster male theory would explain the rapid evolution of male hybrid sterility. It is currently unknown what causes the faster evolution of male sterility, but increased sexual selection on males and the sensitivity of genes involved in male reproduction are two hypotheses that could explain the observation. Here, patterns of hybrid sterility in crosses of genetically divergent copepod populations are examined to test potential mechanisms of faster male evolution. The study species, Tigriopus californicus, lacks differentiated, hemizygous sex chromosomes and appears to have low levels of divergence caused by sexual selection acting upon males. Hybrid sterility does not accumulate more rapidly in males than females in these crosses suggesting that in this taxon male reproductive genes are not inherently more prone to disruption in hybrids.

  13. Genetic consequences of many generations of hybridization between divergent copepod populations.

    Science.gov (United States)

    Edmands, S; Feaman, H V; Harrison, J S; Timmerman, C C

    2005-01-01

    Crosses between populations of the copepod Tigriopus californicus typically result in outbreeding depression. In this study, replicate hybrid populations were initiated with first generation backcross hybrids between two genetically distinct populations from California: Royal Palms (RP) and San Diego (SD). Reciprocal F(1) were backcrossed to SD, resulting in expected starting frequencies of 25% RP/75% SD nuclear genes on either a pure RP cytoplasmic or a pure SD cytoplasmic background. After 1 year of hybridization (up to 15 generations), seven microsatellite loci were scored in two replicates on each cytoplasmic background. Frequencies of the rarer RP alleles increased significantly in all four replicates, regardless of cytoplasmic source, producing a mean hybridity of 0.97 (maximum = 1), instead of the expected 0.50. Explicit tests for heterozygote excess across loci and replicates showed significant deviations. Only the two physically linked markers showed linkage disequilibrium in all replicates. Subsequent fitness assays in parental populations and early generation hybrids revealed lower fitness in RP than SD, and significant F(2) breakdown. Computer simulations showed that selection must be invoked to explain the shift in allele frequencies. Together, these results suggest that hybrid inferiority in early generations gave way to hybrid superiority in later generations.

  14. Isolation and characterization of cytochrome c from the marine copepod Tigriopus californicus.

    Science.gov (United States)

    Rawson, P D; Brazeau, D A; Burton, R S

    2000-05-02

    Mitochondrial energy production requires complex interactions among proteins encoded in both the nuclear and mitochondrial genomes. The intergenomic coevolution of interacting gene products has been previously suggested based on interspecific comparisons of cytochrome c (encoded by the nuclear CYC gene) and cytochrome c oxidase (partly encoded in the mitochondrial DNA by the COX1, COX2 and COX3 genes). In the intertidal copepod, Tigriopus californicus, non-synonymous substitutions in the COX1 gene have previously been found in interpopulation comparisons. In order to determine if CYC also shows interpopulation variation, this gene was isolated from a cDNA library using a degenerate primer/polymerase chain reaction approach. Characterization of a cDNA sequence and 25 genomic DNA sequences derived from four T. californicus populations yielded the following results: (1) the T. californicus CYC gene is interrupted by an intron that occurs at the same position as the intron found in vertebrate CYC genes; (2) there is extensive sequence variation within both the coding region and intron of this gene and the vast majority of this variation occurs between sequences drawn from geographically distinct populations; (3) the coding sequence variation includes a minimum of five amino acid replacement substitutions; (4) segregation of length variants among offspring in an interpopulation cross revealed genotypic ratios consistent with the proposed allelic nature of the CYC variants. These results demonstrate that the requisite genetic variation required for intergenomic coevolution exists in the CYC-COX system in T. californicus.

  15. Acclimation and adaptation to common marine pollutants in the copepod Tigriopus californicus.

    Science.gov (United States)

    Sun, Patrick Y; Foley, Helen B; Handschumacher, Lisa; Suzuki, Amanda; Karamanukyan, Tigran; Edmands, Suzanne

    2014-10-01

    Establishing water quality criteria using bioassays is complicated by variation in chemical tolerance between populations. Two major contributors to this variation are acclimation and adaptation, which are both linked to exposure history, but differ in how long their effects are maintained. Our study examines how tolerance changes over multiple generations of exposure to two common marine pollutants, copper (Cu) and tributyltin oxide (TBTO), in a sexually reproducing marine copepod, Tigriopus californicus. Lines of T. californicus were chronically exposed to sub-lethal levels of Cu and TBTO for 12 generations followed by a recovery period of 3 generations in seawater control conditions. At each generation, the average number of offspring produced and survived to 28 d was determined and used as the metric of tolerance. Lines exposed to Cu and TBTO showed an overall increase in tolerance over time. Increased Cu tolerance arose by generation 3 in the chronically exposed lines and was lost after 3 generations in seawater control conditions. Increased TBTO tolerance was detected at generation 7 and was maintained even after 3 generations in seawater control conditions. It was concluded from this study that tolerance to Cu is consistent with acclimation, a quick gain and loss of tolerance. In contrast, TBTO tolerance is consistent with adaptation, in which onset of tolerance was delayed relative to an acclimation response and maintained in the absence of exposure. These findings illustrate that consideration of exposure history is necessary when using bioassays to measure chemical tolerance.

  16. Molecular and quantitative trait variation within and among populations of the intertidal copepod Tigriopus californicus.

    Science.gov (United States)

    Edmands, Suzanne; Harrison, J Scott

    2003-10-01

    While molecular and quantitative trait variation may be theoretically correlated, empirical studies using both approaches frequently reveal discordant patterns, and these discrepancies can contribute to our understanding of evolutionary processes. Here, we assessed genetic variation in six populations of the copepod Tigriopus californicus. Molecular variation was estimated using five polymorphic microsatellite loci, and quantitative variation was measured using 22-life history and morphometric characters. Within populations, no correlation was found between the levels of molecular variation (heterozygosity) and quantitative variation (heritability). Between populations, quantitative subdivision (Q(ST)) was correlated with molecular subdivision when measured as F(ST) but not when measured as R(ST). Unlike most taxa studied to date, the overall level of molecular subdivision exceeded the level of quantitative subdivision (F(ST) = 0.80, R(ST) = 0.89, Q(ST) = 0.30). Factors that could contribute to this pattern include stabilizing or fluctuating selection on quantitative traits or accelerated rates of molecular evolution.

  17. Proline biosynthesis genes and their regulation under salinity stress in the euryhaline copepod Tigriopus californicus.

    Science.gov (United States)

    Willett, Christopher S; Burton, Ronald S

    2002-08-01

    Diverse organisms regulate concentrations of intracellular organic osmolytes in response to changes in environmental salinity or desiccation. In marine crustaceans, accumulation of high concentrations of proline is a dominant component of response to hyperosmotic stress. In the euryhaline copepod Tigriopus californicus, synthesis of proline from its metabolic precursor glutamate is tightly regulated by changes in environmental salinity. Here, for the first time in a marine invertebrate, the genes responsible for this pathway have been cloned and characterized. The two proteins display the sequence features of homologous enzymes identified from other eukaryotes. One of the cloned genes, delta1-pyrroline-5-carboxylase reductase (P5CR), is demonstrated to have the reductase enzyme activity when expressed in proline-auxotroph bacteria, while the second, delta1-pyrroline-5-carboxylase synthase (P5CS), does not rescue proline-auxotroph bacteria. In contrast to results from higher plants, neither levels of P5CS nor P5CR mRNAs increase in response to salinity stress in T. californicus. Hence, regulation of proline synthesis during osmotic stress in T. californicus is likely mediated by some form of post-transcriptional regulation of either P5CS or P5CR. Understanding the regulation this pathway may elucidate the mechanisms limiting the salinity ranges of marine taxa.

  18. Maladapted gene complexes within populations of the intertidal copepod Tigriopus californicus?

    Science.gov (United States)

    Edmands, Suzanne; Northrup, Sara L; Hwang, Annmarie S

    2009-08-01

    The prevalence of F2 hybrid breakdown in interpopulation crosses of the marine copepod Tigriopus californicus can be explained by disruption of coadapted gene complexes. This study further dissects the nature of hybrid gene interactions, revealing that parental populations may also harbor maladapted gene complexes. Diagnostic molecular markers (14) were assayed in reciprocal F2 hybrids to test for gene interactions affecting viability. Results showed some evidence of nuclear-nuclear coadaptation. Although there were no significant examples of pairwise linkage disequilibrium between physically unlinked loci, one of the two reciprocal crosses did show an overall excess of parental double homozygotes and an overall dearth of nonparental double homozygotes. In contrast, the nuclear-cytoplasmic data showed a stronger tendency toward maladaptation within the specific inbred lines used in this study. For three out of four loci with significant frequency differences between reciprocal F2, homozygotes were favored on the wrong cytoplasmic background. A separate study of reciprocal backcross hybrids between the same two populations (but different inbred lines) revealed faster development time when the full haploid nuclear genome did not match the cytoplasm. The occurrence of such suboptimal gene complexes may be attributable to effects of genetic drift in small, isolated populations.

  19. Very bright green fluorescent proteins from the Pontellid copepod Pontella mimocerami.

    Directory of Open Access Journals (Sweden)

    Marguerite E Hunt

    Full Text Available BACKGROUND: Fluorescent proteins (FP homologous to the green fluorescent protein (GFP from the jellyfish Aequorea victoria have revolutionized biomedical research due to their usefulness as genetically encoded fluorescent labels. Fluorescent proteins from copepods are particularly promising due to their high brightness and rapid fluorescence development. RESULTS: Here we report two novel FPs from Pontella mimocerami (Copepoda, Calanoida, Pontellidae, which were identified via fluorescence screening of a bacterial cDNA expression library prepared from the whole-body total RNA of the animal. The proteins are very similar in sequence and spectroscopic properties. They possess high molar extinction coefficients (79,000 M(-1 cm(- and quantum yields (0.92, which make them more than two-fold brighter than the most common FP marker, EGFP. Both proteins form oligomers, which we were able to counteract to some extent by mutagenesis of the N-terminal region; however, this particular modification resulted in substantial drop in brightness. CONCLUSIONS: The spectroscopic characteristics of the two P. mimocerami proteins place them among the brightest green FPs ever described. These proteins may therefore become valuable additions to the in vivo imaging toolkit.

  20. Predation by the Dwarf Seahorse on Copepods: Quantifying Motion and Flows Using 3D High Speed Digital Holographic Cinematography - When Seahorses Attack!

    Science.gov (United States)

    Gemmell, Brad; Sheng, Jian; Buskey, Ed

    2008-11-01

    Copepods are an important planktonic food source for most of the world's fish species. This high predation pressure has led copepods to evolve an extremely effective escape response, with reaction times to hydrodynamic disturbances of less than 4 ms and escape speeds of over 500 body lengths per second. Using 3D high speed digital holographic cinematography (up to 2000 frames per second) we elucidate the role of entrainment flow fields generated by a natural visual predator, the dwarf seahorse (Hippocampus zosterae) during attacks on its prey, Acartia tonsa. Using phytoplankton as a tracer, we recorded and reconstructed 3D flow fields around the head of the seahorse and its prey during both successful and unsuccessful attacks to better understand how some attacks lead to capture with little or no detection from the copepod while others result in failed attacks. Attacks start with a slow approach to minimize the hydro-mechanical disturbance which is used by copepods to detect the approach of a potential predator. Successful attacks result in the seahorse using its pipette-like mouth to create suction faster than the copepod's response latency. As these characteristic scales of entrainment increase, a successful escape becomes more likely.

  1. First report on the contribution of small-sized species to the copepod community structure of the southern Patagonian shelf (Argentina, 47-55°S

    Directory of Open Access Journals (Sweden)

    Julieta Carolina Antacli

    2014-03-01

    Full Text Available The copepod community structure, with special emphasis on small-sized species, was studied over the southern Patagonian shelf in late summer 2004, applying the first plankton sampling in the region with a fine-mesh (66 μm net. The key role of the copepods Drepanopus forcipatus and Calanus australis was confirmed, but also the high abundance and frequency of occurrence of the microcopepods Oithona helgolandica and Microsetella norvegica and of the medium-sized copepod Ctenocalanus vanus were revealed. Copepod community structure was nearly homogenous over the entire study area. Drepanopus forcipatus, O. helgolandica and M. norvegica were identified as the typical species of the region, although secondarily C. australis and Oithona atlantica also contributed significantly to community similarity across the area. The study of interspecific relationships of dominant copepods indicated that D. forcipatus and C. australis were associated positively with O. helgolandica, while C. vanus, and M. norvegica constituted a separate assemblage with Clausocalanus brevipes and O. atlantica. The importance of fine-mesh-size nets for collecting the smaller size fractions of mesozooplankton and for accurately portraying the mesozooplankton assemblage structure in the area is stressed by this study.

  2. The complete mitochondrial genome of the cyclopoid copepod Paracyclopina nana: a highly divergent genome with novel gene order and atypical gene numbers.

    Science.gov (United States)

    Ki, Jang-Seu; Park, Heum Gi; Lee, Jae-Seong

    2009-04-15

    In this paper, we describe the complete mitogenome of the cyclopoid copepod Paracyclopina nana with emphasis on the highly rearranged gene order and high divergence against published copepod mitogenomes. The P. nana mtDNA is 15,981 bp in length (70.9% AT) and consists of 37 genes (12 protein-coding genes, 2 rRNAs, 23 tRNAs) that are atypical for metazoan mitogenomes. Unusually, it contains an extra tRNA (tRNA-Ala) but it does not contain the ATPase 8 gene. The P. nana mitogenome has a long putative control region with high AT content (1351 bp, 77.0% AT). The Cyt b was considerably short in length, compared to other crustaceans. Compared to typical mitogenomes of arthropods and copepods, the gene order of the P. nana mitogenome is highly rearranged with a novel gene structure. In addition, P. nana has highly divergent mt genes (mostly less than 50%), judged by amino acid substitution. We present the first complete mitogenome sequence from a cyclopoid copepod, thereby increasing our understanding of copepod and crustacean evolution from the mitochondrial point of view.

  3. Community structure of copepods in the oceanic and neritic waters off Adélie and George V Land, East Antarctica, during the austral summer of 2008

    Science.gov (United States)

    Tachibana, Aiko; Watanabe, Yuko; Moteki, Masato; Hosie, Graham W.; Ishimaru, Takashi

    2017-06-01

    Copepods are one of the most important components of the Southern Ocean food web, and are widely distributed from surface to deeper waters. We conducted discrete depth sampling to clarify the community structure of copepods from the epi- to bathypelagic layers of the oceanic and neritic waters off Adélie and George V Land, East Antarctica, in the austral summer of 2008. Notably high diversity and species numbers were observed in the meso- and bathypelagic layers. Cluster analysis based on the similarity of copepod communities identified seven cluster groups, which corresponded well with water masses. In the epi- and upper- mesopelagic layers of the oceanic zone, the SB (Southern Boundary of the Antarctic Circumpolar Current) divided copepod communities. Conversely, in the lower meso- and bathypelagic layers (500-2000 m depth), communities were consistent across the SB. In these layers, the distributions of copepod species were separated by habitat depth ranges and feeding behaviour. The different food webs occur in the epipelagic layer with habitat segregation by zooplankton in their horizontal distribution ranges.

  4. Caracterização morfológica e distribuição temporal de larvas e juvenis de Apareiodon affinis (Steindachner (Osteichthyes, Parodontidae no alto rio Paraná, Paraná Morphological characterization and temporal distribution of larvae and juveniles of Apareiodon affinis (steindachner (osteichthyes, PArodontidae in upper Paraná River, Paraná

    Directory of Open Access Journals (Sweden)

    Andréa Bialetzki

    1998-12-01

    Full Text Available With the purpose of characterizing morphologicaly the larvae and juveniles of Apareiodon affinis (Steindachner, 1879 and to verify their temporal distribution monthly samples were taken at Leopoldo's Inlet, upper Paraná River. The specimens were captured with a conic-cylindrical plankton net of mesh size 0,5mm from March 1991 to February 1992. Soon after identification, the specimens were separeted according to their development (prefle-xion, flexion, posflexion and juvenile and then the moiphometric analyses were performed. The results showed that the larvae were captured from August 1991 to February 1992, with greatest densities in November 1991. The specimens occured in every timetable, however, larvae in pretlexion and flexion were captured during day time and, posflexion and juvenile, at night. According to series of morphological development, high body proportions variation were verifyed mainly in the head lenght, eye diameter and in height body. Moreover, the individuais showed little pigmentation and myomeres number changing between 39 to 42. The majority of morphometric characteristics have negative allometry with the cxception of head lenght with regard to standart lenght that have positive allometry.

  5. Effect of temperature and viscosity on swimming velocity of the copepod Acartia tonsa, brine shrimp Artemia salina and rotifer Brachionus plicatilis

    DEFF Research Database (Denmark)

    Larsen, Poul Scheel; Madsen, C.V.; Riisgard, H.U.

    2008-01-01

    of swimming velocity for a 10 degrees C temperature reduction) that is found to be largest for the brine shrimp Artemia salina nauplius (37 %) and the rotifer Brachionus plicatilis (26%), but negligible for the copepod Acartia tonsa (4%). We suggest that experimental data on change in swimming velocity (V......Beating cilia are important organelles for swimming in many zooplanktonic aquatic organisms, including many invertebrate larvae, rotifers and ciliates, but other planktonic organisms, such as copepods and brine shrimps, use muscle-powered swimming appendages. In recent studies we found......) due to change in kinematic viscosity (v) be correlated in terms of a power law, V proportional to v(-m). The present data on swimming velocity of copepods, brine shrimps and rotifers show values of exponent m approximate to 1.5 to 3, with a trend of decreasing values for increasing size of species...

  6. Effects of calanoid copepod Schmackeria poplesia as a live food on the growth, survival and fatty acid composition of larvae and juveniles of Japanese flounder, Paralichthys olivaceus

    Science.gov (United States)

    Liu, Guangxing; Xu, Donghui

    2009-12-01

    Zooplankton constitutes a major part of the diet for fish larvae in the marine food web, and it is generally believed that copepods can meet the nutritional requirements of fish larvae. In this study, calanoid copepod Schmackeria poplesia, rotifer Brachionus plicatilis and anostraca crustacean Artemia sp. were analyzed for fatty acid contents, and were used as live food for culturing larval Japanese flounder, Paralichthys olivaceus. The total content of three types of HUFAs (DHA, EPA and ARA) in S. poplesia was significantly higher than that in the other two live foods ( Pdiet or Artemia only, and the ratio of EPA/ARA in larvae and juveniles of P. olivaceus fed with S. poplesia was lower than that in the case of feeding with a mixed diet or Artemia only. The present data showed that copepod is the best choice for feeding the larvae and juveniles of fish considering its effects on the survival, growth and nutrition composition of the fish.

  7. Linking climate change to community-level impacts on copepods via a new, trait-based model: Life-history and metabolic mechanisms compared

    DEFF Research Database (Denmark)

    Banas, Neil S.; Møller, Eva Friis; Nielsen, Torkel Gissel;

    A new, trait-based copepod model ("Coltrane": Copepod Life-history Traits and Adaptation to Novel Environments) has been developed, drawing on past work on both optimal annual routines and trait-based plankton metacommunity models, in order to evaluate climate impacts on copepods via 1) phenology...... and life history and 2) temperature and energy budgets in a unified framework. In an idealized global-scale testbed, the model correctly predicts life strategies in large Calanus spp. ranging from multiple generations per year to multiple years per generation. In a Bering Sea testbed, the model replicates...... the dramatic variability in the abundance of C. glacialis/marshallae observed between warm and cold years of the 2000s, and indicates (consistent with recent field studies) that sea ice-linked prey phenology is a more important driver than temperature per se. In a Disko Bay, West Greenland testbed, the model...

  8. Impact of the diatom-derived polyunsaturated aldehyde 2-trans,4-trans decadienal on the feeding, survivorship and reproductive success of the calanoid copepod Temora stylifera.

    Science.gov (United States)

    Kâ, Samba; Carotenuto, Ylenia; Romano, Giovanna; Hwang, Jiang-Shiou; Buttino, Isabella; Ianora, Adrianna

    2014-02-01

    Many diatoms, a major class of unicellular algae contributing to over 45% of oceanic primary production, are known to induce deleterious effects on reproductive processes in crustacean copepods. This is mainly due to the production of teratogenic oxylipins, including polyunsaturated aldehydes (PUAs). Here we tested the direct effect of the PUA 2E,4E-decadienal (DD) on feeding activity, survivorship and reproductive success of the calanoid copepod Temora stylifera. DD-inoculated cultures induced high mortality at concentrations above 3 μg mL(-1) compared to controls in both males and females, with males having a higher mortality. Low DD concentrations triggered an increase in female filtration and ingestion rates. Egg production rates and hatching times were also higher in the presence of DD, whereas egg hatching success decreased with increasing DD concentration. Our study shows, for the first time, that the presence of diatom PUAs may increase feeding rates in copepods.

  9. Effects of Calanoid Copepod Schmackeria poplesia as a Live Food on the Growth, Survival and Fatty Acid Composition of Larvae and Juveniles of Japanese Flounder, Paralichthys olivaceus

    Institute of Scientific and Technical Information of China (English)

    LIU Guangxing; XU Donghui

    2009-01-01

    Zooplankton constitutes a major part of the diet for fish larvae in the marine food web, and it is generally believed that copepods can meet the nutritional requirements of fish larvae. In this study, calanoid copepod Schmackeria poplesia, rotifer Brachionus plicatilis and anostraca crustacean Artemia sp. were analyzed for fatty acid contents, and were used as live food for culturing larval Japanese flounder, Paralichthys olivaceus. The total content of three types of HUFAs (DHA, EPA and ARA) in S. poplesia was significantly higher than that in the other two live foods (P<0.01). Three live organisms were used for raising larvae and juveniles ofParalichthys olivaceus respectively for 15 and 10 d. Then the growth, survival and fatty acid composition of the larvae and juveniles were investigated. The results showed that the larvae and juveniles fed with copepods (S. poplesia) had significantly higher growth rate than thosc fed with the other two organisms (P<0.01). The survival of the flounder larvae fed with copepods was significantly higher than that of the others (P<0.01), and the survival of the juvenile fish fed with copepods was higher than that fed with Artemia (P<0.05). The contents of three types of HUFAs (DHA, EPA and ARA) and the ratio of DHA/EPA in larval and juvenile flounder P. olivaceus were analyzed. The results showed that the contents of DHA, EPA and ARA in the larvae and juveniles fed with S. poplesia were higher than those fed with a mixed diet or Artemia only, and the ratio of EPA/ARA in larvae and juveniles of P. olivaceus fed with S. poplesia was lower than that in the case of feeding with a mixed diet or Artemia only. The present data showed that copepod is the best choice for feeding the larvae and juveniles of fish considering its effects on the survival, growth and nutrition composition of the fish.

  10. Copepod response to ocean acidification in a low nutrient-low chlorophyll environment in the NW Mediterranean Sea

    Science.gov (United States)

    Zervoudaki, S.; Krasakopoulou, E.; Moutsopoulos, T.; Protopapa, M.; Marro, S.; Gazeau, F.

    2017-02-01

    In order to identify how ocean acidification will influence biological interactions and fluxes among planktonic organisms and across trophic levels, a large-scale mesocosm experiment was performed in the oligotrophic Northwestern Mediterranean Sea in the framework of the European MedSeA project. Nine mesocosms were deployed in the Bay of Calvi (Corsica, France) in summer 2012. Six mesocosms were subjected to different levels of CO2 partial pressures (pCO2; 550, 650, 750, 850, 1000 and 1250 μatm) covering the range of atmospheric pCO2 anticipated for the end of this century depending on future emission scenarios, and the last three mesocosms were unaltered (ambient pCO2 of ∼450 μatm). During this 21-day experiment, we monitored copepod egg and naupliar stocks, estimated copepod (Acartia clausi and Centropages typicus) feeding rates and determined the abundance and taxonomic composition of the mesozooplankton community at the start and at the completion of the experiment. This community was clearly dominated by copepods and its final composition slightly varied between mesocosms most likely due to natural and experimental variability that cannot be related to CO2 conditions. The abundances of eggs and nauplii as well as feeding rates of A. clausi and C. typicus on diatoms, dinoflagellates and ciliates showed no significant differences among CO2 levels. The above findings suggest that the experimental set-up especially for the specific trophic conditions and the short duration of the experiment did not provide the information on the effect of acidification that was expected. The acidification might have an effect on planktonic communities and even worsen the problems imposed by food limitation, therefore on this short time scale experiment and under the extreme ologotrophic conditions the signal that dominates was the food limitation.

  11. Laboratory and field efficacy of Pedalium murex and predatory copepod, Mesocyclops longisetus on rural malaria vector, Anopheles culicifacies

    Science.gov (United States)

    Chitra, Thangadurai; Murugan, Kadarkarai; Kumar, Arjunan Naresh; Madhiyazhagan, Pari; Nataraj, Thiyagarajan; Indumathi, Duraisamy; Hwang, Jiang-Shiou

    2013-01-01

    Objective To test the potentiality of the leaf extract of Pedalium murex (P. murex) and predatory copepod Mesocyclops longisetus (M. longisetus) in individual and combination in controlling the rural malarial vector, Anopheles culicifacies (An. culicifacies) in laboratory and field studies. Methods P. murex leaves were collected from in and around Erode, Tamilnadu, India. The active compounds were extracted with 300 mL of methanol for 8 h in a Soxhlet apparatus. Laboratory studies on larvicidal and pupicidal effects of methanolic extract of P. murex tested against the rural malarial vector, An. culicifacies were significant. Results Evaluated lethal concentrations (LC50) of P. murex extract were 2.68, 3.60, 4.50, 6.44 and 7.60 mg/L for I, II, III, IV and pupae of An. culicifacies, respectively. Predatory copepod, M. longisetus was examined for their predatory efficacy against the malarial vector, An. culicifacies. M. longisetus showed effective predation on the early instar (47% and 36% on I and II instar) when compared with the later ones (3% and 1% on III and IV instar). Predatory efficacy of M. longisetus was increased (70% and 45% on I and II instar) when the application was along with the P. murex extract. Conclusions Predator survival test showed that the methanolic extract of P. murex is non-toxic to the predatory copepod, M. longisetus. Experiments were also conducted to evaluate the efficacy of methanolic extract of P. murex and M. longisetus in the direct breeding sites (paddy fields) of An. culicifacies. Reduction in larval density was very high and sustained for a long time in combined treatment of P. murex and M. longisetus.

  12. Adverse effects of MWCNTs on life parameters, antioxidant systems, and activation of MAPK signaling pathways in the copepod Paracyclopina nana.

    Science.gov (United States)

    Kim, Duck-Hyun; Puthumana, Jayesh; Kang, Hye-Min; Lee, Min-Chul; Jeong, Chang-Bum; Han, Jeonghoon; Hwang, Dae-Sik; Kim, Il-Chan; Lee, Jin Wuk; Lee, Jae-Seong

    2016-10-01

    Engineered multi-walled carbon nanotubes (MWCNTs) have received widespread applications in a broad variety of commercial products due to low production cost. Despite their significant commercial applications, CNTs are being discharged to aquatic ecosystem, leading a threat to aquatic life. Thus, we investigated the adverse effect of CNTs on the marine copepod Paracyclopina nana. Additional to the study on the uptake of CNTs and acute toxicity, adverse effects on life parameters (e.g. growth, fecundity, and size) were analyzed in response to various concentrations of CNTs. Also, as a measurement of cellular damage, oxidative stress-related markers were examined in a time-dependent manner. Moreover, activation of redox-sensitive mitogen-activated protein kinase (MAPK) signaling pathways along with the phosphorylation pattern of extracellular signal-regulated kinase (ERK), p38, and c-Jun-N-terminal kinases (JNK) were analyzed to obtain a better understanding of molecular mechanism of oxidative stress-induced toxicity in the copepod P. nana. As a result, significant inhibition on life parameters and evoked antioxidant systems were observed without ROS induction. In addition, CNTs activated MAPK signaling pathway via ERK, suggesting that phosphorylated ERK (p-ERK)-mediated adverse effects are the primary cause of in vitro and in vivo endpoints in response to CNTs exposure. Moreover, ROS-independent activation of MAPK signaling pathway was observed. These findings will provide a better understanding of the mode of action of CNTs on the copepod P. nana at cellular and molecular level and insight on possible ecotoxicological implications in the marine environment.

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

    Science.gov (United States)

    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.

  14. Linking climate change to community-level impacts on copepods via a new, trait-based model: Life-history and metabolic mechanisms compared

    DEFF Research Database (Denmark)

    Banas, Neil S.; Møller, Eva Friis; Nielsen, Torkel Gissel

    2016-01-01

    and life history and 2) temperature and energy budgets in a unified framework. In an idealized global-scale testbed, the model correctly predicts life strategies in large Calanus spp. ranging from multiple generations per year to multiple years per generation. In a Bering Sea testbed, the model replicates...... and physiology of local populations of C. finmarchicus, C. glacialis, and C. hyperboreus. Futhermore, the model replicates the observed range of stored lipid content of these copepod populations (30–60%, C. finmarchicus–C. hyperboreus), suggesting a means for linking changes in temperature and primary production...... to the energy content as well as size structure of the copepod community....

  15. Ecological effects of scrubber water discharge on coastal plankton: Potential synergistic effects of contaminants reduce survival and feeding of the copepod Acartia tonsa

    DEFF Research Database (Denmark)

    Koski, Marja; Stedmon, Colin; Trapp, Stefan

    2017-01-01

    and hydrocarbons. We investigated 1) the threshold concentrations of scrubber discharge water for survival, feeding and reproduction of the copepod Acartia tonsa, 2) whether the effects depend on the exposure route and 3) whether exposure to discharge water can be detected in field-collected organisms. A direct...... exposure to discharge water increased adult copepod mortality and reduced feeding at metal concentrations which were orders of magnitude lower than the lethal concentrations in previous single-metal studies. In contrast, reproduction was not influenced by dietary uptake of contaminants. Scrubber water...

  16. Effects of three PBDEs on development, reproduction and population growth rate of the harpacticoid copepod Nitocra spinipes

    DEFF Research Database (Denmark)

    Breitholtz, M.; Wollenberger, Leah

    2003-01-01

    The current knowledge concerning effects of polybrominated diphenyl ethers (PBDEs) on aquatic organisms is very limited. A full life-cycle (less than or equal to 26 days exposure) ecotoxicity test with the particle-feeding copepod Nitocra spinipes was therefore used to study effects of BDE-47, -99...... and that ingestion of particle-adsorbed PBDEs most likely is the predominant route of exposure in N. spinipes. However, to further improve the usefulness of laboratory effect levels of PBDEs and other lipophilic substances for environmental risk assessment, it is important to develop ecotoxicological tools, which...

  17. Influence of UVB radiation on the lethal and sublethal toxicity of dispersed crude oil to planktonic copepod nauplii

    DEFF Research Database (Denmark)

    Almeda, Rodrigo; Harvey, Tracy E.; Connelly, Tara L

    2016-01-01

    Toxic effects of petroleum to marine zooplankton have been generally investigated using dissolved petroleum hydrocarbons and in the absence of sunlight. In this study, we determined the influence of natural ultraviolet B (UVB) radiation on the lethal and sublethal toxicity of dispersed crude oil...... in the sea after oil spills are highly toxic to copepod nauplii and that natural levels of UVB radiation substantially increase the toxicity of crude oil to these planktonic organisms. Overall, this study emphasizes the importance of considering sunlight in petroleum toxicological studies and models...

  18. Ingestion rate and gut clearance in the planktonic copepod Centropages hamatus in relation to food concentration and temperature

    DEFF Research Database (Denmark)

    Kiørboe, Thomas; Møhlenberg, F.; Nicolajsen, Hanne

    1982-01-01

    .degree. C. Within the temperature interval studied (1.degree.-15.degree. C), maximum ingestion rate increased with temperature with a Q10 of 3.9. Gut clearance was estimated by following the exponential decrease in the gut content of plant pigments (measured fluorimetrically) with time after feeding...... be considered an estimate of ingestion rate, yielded values similar to ingestion rates actually measured. This implies that in situ algal ingestion rates may be estimated from measurements of the content of plant pigments in the guts of freshly caught copepods....

  19. Population dynamics and production of the small copepod Oithona spp. in a subarctic fjord of West Greenland

    DEFF Research Database (Denmark)

    Zamora-Terol, Sara; Kjellerup, Sanne; Swalethorp, Rasmus

    2014-01-01

    The small cyclopoid copepod Oithona is widely occurring in polar areas; however, knowledge of its biology and ecology is very limited. Here, we investigate the population dynamics, vertical distribution, and reproductive characteristics of Oithona spp. from late winter to summer, in a subarctic...... production rates (EPR) were low in winter–early spring (0.13 ± 0.03 eggs female-1 day-1) and reached maximum values in summer (1.6 ± 0.45 eggs female-1 day-1). EPR of Oithona spp. showed a significantly positive relationship with both temperature and protozooplankton biomass, and the development...

  20. Comparative oxygen consumption rates of subitaneous and delayed hatching eggs of the calanoid copepod Acartia tonsa (Dana)

    DEFF Research Database (Denmark)

    Hansen, Benni Winding; Drillet, Guillaume

    2013-01-01

    Life history strategies can be adaptations to existence in e.g. unstable environments. Under stressful environmental conditions mobile species tend to migrate to more suitable places, but migration in time by dormancy is another durable strategy. More than 50 species of calanoid copepods can...... history trait allowing the spread of hatching over a period of time (a month or two), increasing the likelihood that some offspring encounter suitable environmental conditions and can contribute to the pelagic population of neritic calanoids in environmental fluctuating environments....