WorldWideScience

Sample records for calanoid copepod acartia

  1. 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...

  2. 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...

  3. 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...

  4. 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

  5. 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...

  6. 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

    (4) after the copepod fed on DMSP-containing alga. DCB abundance associated with fecal pellets averaged 1.2 X 10(4) cells pellet(-1). In enrichment cultures, the DCB grew with a doubling time of 1.1- 2.9 days, and consumed DMSP at a rate of 4.5-7.5 fmol cell(-1) day(-1). The apparent DMSP-to-DMS conversion......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...

  7. 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...... content in early nauplii indicates that A. tonsa is a valuable source for nutritional energy for first-feeding fish larvae and should be further exploited for aquaculture purposes. Enhancements to FAA abundances in nauplii through manipulation of maternal diets could be of future interest, as copepod...

  8. Changes in free amino acid content during naupliar development of the Calanoid copepod Acartia tonsa.

    Science.gov (United States)

    Rayner, Thomas Allan; Jørgensen, Niels Ole Gerslev; Drillet, Guillaume; Hansen, Benni Winding

    2017-08-01

    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 revealed the largest change in relative abundance during naupliar development and declined from 29.0% at first nauplius stage to 7.1% at later stages. The high FAA pool in early naupliar stages may be necessary for naupliar development due to an absence of feeding at first development stages. The high FAA content in early nauplii indicates that A. tonsa is a valuable source for nutritional energy for first-feeding fish larvae and should be further exploited for aquaculture purposes. Enhancements to FAA abundances in nauplii through manipulation of maternal diets could be of future interest, as copepod nauplii can contain a substantial pool of FAAs at first development stage. Copyright © 2017. Published by Elsevier Inc.

  9. The constraints of high density production of the calanoid copepod Acartia tonsa Dana

    DEFF Research Database (Denmark)

    Vu, Minh T. T.; Hansen, Benni W.; Kiørboe, Thomas

    2017-01-01

    Copepods are excellent live feed for marine fish larvae in aquaculture. Culturing copepods at high density is important to increase the total egg yield, but this is still a main challenge. To address this, we conducted experiments to test factors affecting the egg harvest potential of the well...

  10. 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 main...

  11. 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....... An interesting trait with the species is that the eggs can be provoked into a resting stage, where the egg can be stored for one year, similar to Artemia cysts. This is the most promising storage technique for distribution of copepod eggs to aquaculture facilities worldwide. The eggs can be hatched...... 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...

  12. 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

    capacity. A. tonsa fed the unicellular algae Rhodomonas baltica were registered for four weeks in triplicate 50 L tanks in each system. Water quality parameters were recorded daily for temperature, oxygen, pH, salinity, particles and every five days for nitrogenous waste and bacteria through...... species. The RAS also needs a further optimisation of water quality by a denitrifying filter component to stabilize for copepod cultivation and an implementation of disease control treatment is also required....

  13. The fate of lipids during development and cold-storage of eggs in the laboratory-reared calanoid copepod, Acartia tonsa Dana, and in response to different algal diets

    DEFF Research Database (Denmark)

    Støttrup, Josianne; Bell, J.G.; Sargent, J.R.

    1999-01-01

    The calanoid copepod Acartia tonsa was sampled throughout one generation to examine the fate of lipids during development in culture. Effects of dietary input were examined by feeding A. tonsa for at least one generation with specific monoalgal cultures. Four different algae were tested: the cryp...

  14. 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

    (spiked feeding), in four equal pulses (pulsed feeding), and evenly over 24 h (continuous feeding). The feeding regimes were investigated at low food levels (~200 µg C L−1) and at full-saturated food levels (~1800 µg C L−1). As photoperiod may have an effect on feeding uptake and productivity, the present...... experiments were segregated into two light regimes, one in darkness (0L:24D) and one in light (24L:0D). Acartia tonsa exposed to fully saturate feed levels developed twice as fast as at low saturated feed levels. A significantly higher total egg production from copepods was observed, equal to 53.5 % more eggs...

  15. Tolerance of un-ionized ammonia in live feed cultures of the calanoid copepod Acartia tonsa Dana

    DEFF Research Database (Denmark)

    Jepsen, Per Meyer; Andersen, Claus V. B.; Schjelde, Johannes

    2015-01-01

    Optimal water quality is considered as being a restriction for marine copepod cultures for live feed. There is a lack of knowledge on the water-quality conditions in copepod cultures and the effect on copepods. Few studies have investigated the effect of ammonia on copepods, and fewer reports No ...

  16. A comprehensive and precise quantification of the calanoid copepod Acartia tonsa (Dana) for intensive live feed cultures using an automated ZooImage system

    DEFF Research Database (Denmark)

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

    2014-01-01

    The copepod Acartia tonsa (Dana) is a promising live feed species for marine larviculture. A considerable progress has been made on the culturing technique for mass production, yet the application of automatic systems for quantification of A. tonsa development stages and biomass has largely been...... and 6 non-copepod (debris) groups. ZooImage used this training set for automatic discrimination through a random forest algorithm with the general accuracy of 92.8%. The ZooImage showed no significant difference in classifying solitary eggs, or mixed nauplii stages and copepodites compared to personal...

  17. Effects of Salinity, Commercial Salts, and Water Type on Cultivation of the Cryptophyte Microalgae Rhodomonas salina and the Calanoid Copepod Acartia tonsa

    DEFF Research Database (Denmark)

    Jepsen, Per Meyer; Thoisen, Christina V.; Carron-Cabaret, Thibaut

    2018-01-01

    was to investigate the applicability of commercial salts and clarify the potential effects on the cultivation of the microalga Rhodomonas salina and the copepod Acartia tonsa. Three commercial salts were tested, Red Sea Salt (RS), Red Sea – Coral Pro Salt (CP), and Blue Treasure Salt. R. salina was cultured......Marine aquaculture facilities positioned far from the sea need access to seawater (SW); hence, commercial salts are often the chosen solution. In marine hatcheries, most fish larvae require live feed (zooplankton) that are in turn fed with microalgae. The objective of this research...

  18. 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....

  19. Population dynamics of calanoid copepods and the implications of their predation by clupeid fish in the Central Baltic Sea

    DEFF Research Database (Denmark)

    Möllmann, C.; Köster, Fritz

    2002-01-01

    Population dynamics of major Baltic calanoid copepod species in the Gotland Basin during the last two decades were characterized by a decline of Pseudocalanus elongatus associated with declining salinities, and an increase of Temora longicornis and Acartia spp. potentially due to warmer condition...... temperature-driven increase in the T. longicornis stock, as was observed for Acartia spp., which was not significantly consumed...

  20. 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

  1. 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 Acartia...

  2. A new large egg type from the marine live feed calanoid copepod Acartia tonsa (Dana) – Perspectives for selective breeding of designer feed for hatcheries

    DEFF Research Database (Denmark)

    Halsen Hammarvold, Stian; Glud, Ronnie N.; Evjemo, Jan Ove

    2015-01-01

    Mass cultivation ofmarine copepods as live feed requires predictable and uniform production of a standard product for the end users, the hatcheries. A previously undescribed large egg type, measuring a mean diameter of 106.5 μm, was characterized and compared to normal eggs (82.3 μm) from...

  3. Effect of heterotrophic versus autotrophic food on feeding and reproduction of the calanoid copepod Acartia tonsa : relationship with prey fatty acid composition

    DEFF Research Database (Denmark)

    Broglio, E.; Jonasdottir, Sigrun; Calbet, A.

    2003-01-01

    Gymnodinium sanguineum. The diets were also analyzed for fatty acid contents and composition, relationships with EPE and reproductive success were determined. Clear differences were found in the fatty acid contents and the composition of the different diets offered, but these differences did not correspond...... with variability in EPE. However, egg viability was correlated with ingestion of certain prey essential fatty acids; interestingly, our data do not show that ciliates and heterotrophic dinoflagellates are nutritionally superior prey for marine copepods, contrary to general expectations....

  4. Accumulation of mercury by the marine copepod Acartia clausi

    National Research Council Canada - National Science Library

    弘田, 禮一郎; 浅田, 順子; 田島, 静子; 藤木, 素士

    1983-01-01

    .... Such results srggest that methylmercury in the sea watre is accumulated rapidly by Acartia clausi, and that the concentration of methylmercury in copepods and sea watre reached equilibrium within the experimental period (24 hours).

  5. Cryptecodinium cohnii: a promising prey toward large-scale intensive rearing of the live feed copepod Acartia tonsa (Dana)

    DEFF Research Database (Denmark)

    Jakobsen, Hans Henrik; Thoisen, Christina Vinum; Hansen, Benni Winding

    2017-01-01

    , the planktonic calanoid copepod Acartia tonsa. We found that A. tonsa fed and transformed ingested C. cohnii into new production well, although the gross growth efficiency was somewhat lower (~22%) than those reported in the literature when fed the autotrophic microalgae Rhodomonas salina (> 36%). We also....... The trade-off of switching to the heterotrophic dinoflagellate diet is that the copepod performance is about 40% lower. Still, we propose that eliminating light in the rearing of copepod feed makes C. cohnii an interesting alternative and an economical feasible feed worth pursuing in large-scale rearing...

  6. Distribution and mortality of diapause eggs from calanoid copepods in relation to sedimentation regimes

    DEFF Research Database (Denmark)

    Sichlau, Mie Hylstofte; Hansen, Jørgen L.S.; Andersen, Thorbjørn J.

    2011-01-01

    Distribution, abundance and age of diapause eggs from three species of calanoid copepods (in particular from Acartia spp. most likely Acartia tonsa, and Centropages hamatus and less numerous from Temora longicornis) were recorded in sediment profiles by enumerating hatched nauplii from incubated...... sediment samples. Phytoplankton pigments and 210Pb and 137Cs analyses indicated that the sedimentation regimes were different between two southern and two northern stations of the island Funen, Denmark. Significant variations in vertical distribution, abundance and mortality of diapause eggs were found...... vs. 0.07–0.08 year−1 with no systematic pattern among species. The differences in abundance, mortality and age of the diapause eggs are suggested to be due to the sediment characteristics in which they are buried....

  7. Do inactivated microbial preparations improve life history traits of the copepod Acartia tonsa?

    Science.gov (United States)

    Drillet, Guillaume; Rabarimanantsoa, Tahina; Frouël, Stéphane; Lamson, Jacob S; Christensen, Anette M; Kim-Tiam, Sandra; Hansen, Benni W

    2011-10-01

    We have tested a microbial preparation with probiotic effects (PSI; Sorbial A/S DANISCO) on the calanoid copepod Acartia tonsa (Dana) development time and reproduction effectiveness in culture. The hypotheses were that PSI increases the productivity and quality of copepods in culture (increased egg 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 show that the addition of PSI to the algal food increased the individual size of the adult females and their egg production. The PSI, together with Rhodomonas salina, also increased the HS of the eggs produced by PSI-treated females. These effects were observed despite that the biochemical analysis of the PSI revealed that it is a nutritionally poor food lacking essential fatty acids, and hence it cannot be used alone to raise copepods but instead as a food additive. This is the first demonstration that the effectiveness of copepod culturing can be improved using microbial preparations as a food additive.

  8. Effect of 2,4-dihydroxybenzophenone (BP1) on early life-stage development of the marine copepod Acartia tonsa at different temperatures and salinities

    DEFF Research Database (Denmark)

    Kusk, Kresten Ole; Avdolli, Manola; Wollenberger, Leah

    2011-01-01

    Benzophenone (BP)-type ultraviolet (UV) filters are widely used in cosmetic and sunscreen products and can enter the aquatic environment. Therefore, we investigated the subchronic toxicity of 2,4-dihydroxybenzophenone (BP1) on the marine calanoid copepod Acartia tonsa in an early life-stage devel......Benzophenone (BP)-type ultraviolet (UV) filters are widely used in cosmetic and sunscreen products and can enter the aquatic environment. Therefore, we investigated the subchronic toxicity of 2,4-dihydroxybenzophenone (BP1) on the marine calanoid copepod Acartia tonsa in an early life...... a copepodite stage (DT(½) ) at the different conditions were calculated. The DT(½) values decreased from 296 h at 15°C to 89 h at 25°C and were also affected by salinity (126 h at 15‰ and 167 h at 30‰), whereas the light:dark regime and culture density influenced development only to a minor extent. BP1...

  9. Cyclopoid and calanoid copepod biodiversity in Indonesia

    Directory of Open Access Journals (Sweden)

    Victor R. Alekseev

    2013-10-01

    Full Text Available Recent limnological investigations conducted on the large lakes of Indonesia provide valuable physical and ecological data for future environmental and developmental programmes, yet few studies have focused on zooplankton taxonomy. Here we describe Eucyclops troposperatus Alekseev et Yusoff n. sp. from a pond in Sumatra, and Mesocyclops jakartensis Alekseev n. sp. from a city pond in Jakarta, Java. In the pelagic zone of the lakes of Sulawesi we found only few copepod species. For the endemic cyclopoid Tropocyclops matanoensis Defaye, 2007, we propose a new subgenus, Defayeicyclops n. subg., and provide more data on the morphology as well as scanning electron microscopy and confocal laser scanning images of Tropocyclops (Defayeicyclops matanoensis. Two other cyclopoid species were possibly introduced to Sulawesi: Mesocyclops aequatorialis similis Van de Velde, 1984 from Africa and Thermocyclops crassus (Fischer, 1853 from Eurasia. A new subspecies, Phyllodiaptomus praedictus sulawesensis Alekseev et Vaillant n. ssp. (Calanoida, Diaptomidae, is described from the plankton of lake Tondano, North Sulawesi, Indonesia. The new subspecies resembles P. blanci (de Guerne et Richard, 1896 and P. wellekensae Dumont et Reddy, 1992. Phyllodiaptomus praedictus sulawesensis appears to be endemic to Sulawesi island. The form matanensis formerly treated as a subspecies of Eodiaptomus wolterecki Brehm, 1933 is here elevated to species rank, E. matanensis Brehm, 1933. A preliminary list of the copepod species found in Sulawesi and other large islands of Indonesia now includes more than 60 species. An updated key to the Southeast Asian species of the genus Eucyclops is provided.

  10. 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.

  11. Prey switching behaviour in the planktonic copepod Acartia tonsa

    DEFF Research Database (Denmark)

    Kiørboe, Thomas; Saiz, E.; Viitasalo, M.

    1996-01-01

    The copepod Acartia tonsa has 2 different prey encounter strategies. It can generate a feeding current to encounter and capture immobile prey (suspension feeding) or it can sink slowly and perceive motile prey by means of mechanoreceptors on the antennae (ambush feeding). We hypothesized that A...... (Strombidium sulcatum). Our data demonstrate prey switching in A. tonsa, both in terms of behaviour and in terms of feeding rates on the alternative prey. The time allocated to ambush and suspension feeding changed with the composition of the food, and clearance of diatoms was, accordingly, negatively related...... to the availability of ciliates. In contrast, clearing of ciliates was almost constant and independent of the availability of the alternative prey (diatoms), probably because this particular ciliate species (in contrast to most other microzooplankters) is unable to escape a feeding current and, thus, can also...

  12. 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

  13. Effects of anti-androgens cyproterone acetate, linuron, vinclozolin, and p,p'-DDE on the reproductive organs of the copepod Acartia tonsa

    DEFF Research Database (Denmark)

    Watermann, Burkard T.; Albanis, Triantafyllos A.; Galassi, Silvana

    2016-01-01

    The study was performed to detect the effects of anti-androgenic compounds on the reproduction. In this paper alterations observed in the marine calanoid copepod Acartia tonsa exposed to environmental concentrations of cyproterone acetate (CPA), linuron (LIN), vinclozolin (VIN), and 1,1-dichloro-......,2-bis(p-chlorophenyl)ethylene (p,p'-DDE) for 21 days covering a full life cycle are described. Histological alterations were studied with a focus on reproductive organs, gonad and accessory sexual glands. Exposure to ≥1.2 µg L−1 CPA caused degeneration of spermatocytes and deformation...

  14. 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...

  15. Feeding selectivity of calanoid copepods on phytoplankton in Jangmok Bay, south coast of Korea

    Science.gov (United States)

    Jang, Min-Chul; Shin, Kyoungsoon; Lee, Tongsup; Noh, Il

    2010-06-01

    Grazing impacts of calanoid copepods on size-fractionated phytoplankton biomass [chlorophyll (Chl)- a] were measured in Jangmok Bay, Geoje Island, Korea, monthly from November 2004 to October 2005. The ingestion rate of calanoid copepods on total phytoplankton biomass ranged between 1 and 215 ng Chl- a copepod-1 day-1 during bottle incubations. Results indicated that microphytoplankton (> 20 μm) was the primary food source for calanoid copepods in grazing experiments on 3 phytoplankton size categories ( 20 μm). The ingestion rate on microphytoplankton showed a significant increase (r = 0.93, p feed efficiently on picophytoplankton (< 3 μm) due to unfavorable size. Calanoid copepods removed between 0.1% and 27.7% (average, 3.6 ± 15.8%) of the phytoplankton biomass daily during grazing experiments. Grazing pressure was high in winter and early spring (January-March: 15.6-27.7%), while low in summer (June-August: -33.1-0.0%) and autumn (September-November: -1.4-5.1%). Results suggest that calanoid copepods play an important role in controlling the biomass and size structure of phytoplankton in winter and early spring.

  16. Minimizing the use of fish oil enrichment in live feed by use of a self-enriching calanoid copepod Pseudodiaptomus annandalei

    DEFF Research Database (Denmark)

    Rayner, Thomas Allan; Hwang, Jiang-Shiou; Hansen, Benni Winding

    2017-01-01

    Unlike some harpacticoid and cyclopoid copepods, calanoid copepods are considered unable to enhance their highly unsaturated fatty acid (HUFA) profile in sufficient quantities if at all. This study demonstrates the capability of significant HUFA enhancements in the calanoid Pseudodiaptomus...

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

    DEFF Research Database (Denmark)

    Dorosz, Julia Natalia A; 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...... copepod species from the exact same environment may host significantly different microbiomes. Hence, different copepod species are either not colonized by the same bacteria assemblages or support colonization/growth of different bacteria populations, leading to distinct copepod microbiomes....

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

    DEFF Research Database (Denmark)

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

    2017-01-01

    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...

  19. 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...

  20. 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...

  1. Diapause in Calanoid Copepods: within-clutch hatching patterns

    Directory of Open Access Journals (Sweden)

    Bart T. DE STASIO

    2004-09-01

    Full Text Available Diapause is a major life history feature of many invertebrate organisms. Determining the phenology of diapause is critical for understanding survival and reproductive success of individuals as well as the long-term viability of many populations. The time spent in dormancy by individuals and variability among offspring in the duration of dormancy are two important aspects of invertebrate life histories. Some data are available, especially on duration of diapause, for plants and insects, but little information is available concerning variability among offspring in diapause traits. This is especially true for crustacean zooplankton, where essentially no information has been published on duration of diapause or variability among offspring in diapause timing or dynamics. Here I present data on the duration of diapause, and variability among offspring for diapause characteristics. The freshwater calanoid copepod Onychodiaptomus sanguineus, an obligately sexual species, was collected from Bullhead Pond, Rhode Island, U.S.A., and raised under conditions in the laboratory to induce production of diapausing eggs. One hundred clutches of these diapausing eggs (920 total eggs were incubated for over two years in a full-factorial experiment testing the effects of temperature and photoperiod cycles on the hatching dynamics and duration of diapause. Overall hatching success was highest (approximately 86% for eggs exposed to simultaneous temperature and photoperiod cycles mimicking natural changes, and was lowest (approximately 20% when eggs were incubated at constant temperature (4 °C and in constant dark conditions. The highest fraction of eggs hatched at approximately 550 days of age, but the age of eggs at hatching was highly variable among clutches. There was also large variability within clutches for hatching patterns, with some clutches containing eggs that all hatched synchronously and others in which eggs hatched more continuously throughout the

  2. Wax ester composition influences the diapause patterns in the copepod Calanoides acutus

    Science.gov (United States)

    Pond, David W.; Tarling, Geraint A.; Ward, Peter; Mayor, Daniel J.

    2012-01-01

    Many calanoid copepods inhabiting high latitude environments overwinter at depth in the water column in a state of diapause and the large wax ester reserves that they contain are central to this process. Here we compare the abundance, depth distribution, lipid content and wax ester composition of individual CV Calanoides acutus collected from the Southern Ocean at depth horizons ranging from the surface to 1000 m. Abundances of CV C. acutus varied considerably between locations, ranging from 44 to 1256 m -2. Levels of total lipid in the copepods increased with depth at a rate of around 100 μg per 100 m depth between 200 and 1000 m. Fatty acid composition of the wax esters reflected that of the local prey community, with a spectrum of diatom to flagellate dominated profiles corresponding to different microplankton environments. Copepods with highest levels of total lipid also contained highest levels of the highly unsaturated diatom fatty acid biomarker 20:5(n-3), and occupied the deepest depths during diapause. In addition, unsaturation levels of both the fatty acid and fatty alcohol moieties of the wax esters in the copepods increased with depth. This has implications for the buoyancy of these organisms: higher unsaturation makes the lipid likely to change from liquid to solid state at overwintering depths, increasing their specific gravity. These findings emphasise functional role of n-3 fatty acids in the diapause life-phase of calanoid copepods and in particular the importance of fatty acids from diatoms for overwintering.

  3. 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

    of ciliate biomass throughout the study. Due to low copepod abundance in January through March estimated grazing pressure was not sufficient to control phytoplankton biomass until after the diatom spring bloom. Egg production rates were constant for Centropages hamatus (similar to 20 eggs female(-1) day(-1......)) on all dates but more variable (1-26 eggs female(-1) day(-1)) for the other species. Temora longicornis and Acartia sp. both revealed their lowest fecundity during the bloom...

  4. 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

    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...... of unsaturated fatty acids, but the amount of fatty acids compared to their carbon weight was very low and, therefore, it was considered as a poor food source. We propose a short-term interruption of food supply to copepod cultures in order to mitigate bloom formation of ciliates. This will force copepods...

  5. Culture conditions affect the nutritional value of the copepod Acartia tonsa

    Directory of Open Access Journals (Sweden)

    Arne M. Malzahn

    2015-01-01

    Full Text Available Live feed are still necessary for the rearing of larval stages of several fish species, especially marine ones. Compared to Artemia, copepods are of superior quality. This is based on a suite of traits like size, movement, and nutritional value. Copepods are for example usually high in protein and fatty acids. Essential fatty acid profiles reflect to a large degree the fatty acid supply, which provides the opportunity to manipulate fatty acid profiles of, amongst others, copepods. By manipulating nutrient supply of the algae Rhodomonas salina we were able to double essential fatty acid concentrations in naupliar and copepodit life stages of the copepod Acartia tonsa. However, this lead to growth depression rather than to increased growth rates in a series of consumer species, including larval fish. The reason for the growth depression is likely to be mineral deficiencies occurring along with the nutrient manipulation of the algae.

  6. Hydrodynamic signal perception in the copepod Acartia tonsa

    DEFF Research Database (Denmark)

    Kiørboe, Thomas; Saiz, E.; Visser, Andre

    1999-01-01

    Copepods may remotely detect predators from the velocity gradients these generate in the ambient water. Each of the different components and characteristics of a velocity gradient (acceleration, vorticity, longitudinal and shear deformation) can cause a velocity difference between the copepod and...... deformation rates are just sufficient to allow efficient predator detection while at the same time just below maximum turbulent deformation rates, thus preventing inordinate escapes....

  7. The cultivation of Acartia tonsa Dana for use as a live food source for marine fish larvae

    DEFF Research Database (Denmark)

    Støttrup, Josianne; Richardson, Katherine; Kirkegaard, Eskild

    1986-01-01

    The marine calanoid copepod Acartia tonsa has been continuously cultivated in the laboratory at the Danish Institute for Fisheries and Marine Research for over 70 generations. A description of the cultivation procedures is presented in this paper. Adult copepods are maintained in 200–450-l tanks ...

  8. Short-term and long-term effects of the toxic dinoflagellate Alexandrium minutum on the copepod Acartia clausi

    OpenAIRE

    Frangópulos, M.; Guisande, C.; Maneiro, I.; Riveiro, Isabel; José M. Franco

    2000-01-01

    Several experiments were performed to determine the effects of cell toxin concentration, composition and toxicity of Alexandrium minutum on ingestion rate, egg production, hatching success and naupliar fitness of the copepod Acartia clausi. A combination of A. minutum and nontoxic algae (Prorocentrum micans, Tetraselmis suecica and Isochrysis galbana) was used as food. Copepods ingested a higher amount of A. minutum cells as the concentration of these toxic dinoflagellates increased, and a...

  9. 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.

  10. Phylogeography of the calanoid copepods Calanus helgolandicus and C. euxinus suggests Pleistocene divergences between Atlantic, Mediterranean, and Black Sea populations

    NARCIS (Netherlands)

    Papadopoulos, L.N.; Peijnenburg, K.T.C.A.; Luttikhuizen, P.C.

    2005-01-01

    Molecular systematic analyses of marine taxa are crucial for recording ocean biodiversity, so too are elucidation of the history of population divergence and the dynamics of speciation. In this paper we present the joined phylogeography of the calanoid copepod Calanus helgolandicus (Claus 1863) from

  11. Intraspecific differences in lipid content of calanoid copepods across fine-scale depth ranges within the photic layer.

    Directory of Open Access Journals (Sweden)

    Margarita Zarubin

    Full Text Available Copepods are among the most abundant and diverse groups of mesozooplankton in the world's oceans. Each species has a certain depth range within which different individuals (of the same life stage and sex are found. Lipids are accumulated in many calanoid copepods for energy storage and reproduction. Lipid content in some species increases with depth, however studies so far focused mostly on temperate and high-latitude seasonal vertically migrating copepods and compared lipid contents among individuals either from coarse layers or between diapausing, deep-dwelling copepods and individuals found in the photic, near-surface layer. Here we examined whether lipid contents of individual calanoid copepods of the same species, life stage/sex differ between finer depth layers within the upper water column of subtropical and Arctic seas. A total of 6 calanoid species were collected from samples taken at precise depths within the photic layer in both cold eutrophic and warm oligotrophic environments using SCUBA diving, MOCNESS and Multinet. Measurements of lipid content were obtained from digitized photographs of the collected individuals. The results revealed significant differences in lipid content across depth differences as small as 12-15 meters for Mecynocera clausi C5 and Ctenocalanus vanus C5 (Red Sea, Clausocalanus furcatus males and two clausocalanid C5s (Mediterranean Sea, and Calanus glacialis C5 (Arctic. We suggest two possible explanations for the differences in lipid content with depth on such a fine scale: predator avoidance and buoyancy.

  12. Comparison of Turbulence-Copepod Interaction: Temora longicornis vs. Acartia tonsa

    Science.gov (United States)

    de Jesus-Villanueva, N. H.; Young, D. L.; Webster, D. R.; Yen, J.

    2014-11-01

    The purpose of this study is to examine the behavioral response of the marine copepod Temora longicornisto a Burgers' vortex intended to mimic the characteristics of a turbulent vortex that a copepod is likely to encounter in the coastal or near surface zone. Copepod behavioral assays were conducted for two turbulence levels corresponding to mean turbulent dissipation rates of 0.009 (Level 2) and 0.096 (Level 3) cm2/s3. The Burgers' vortex parameters (i.e., circulation and axial strain rate) are specified to match a vortex corresponding to the median viscous dissipation rate for each target turbulence level. The behavioral response of T. longicornis compared to Acartia tonsa is of particular interest due to differences in swim style (cruiser vs. hop-sinker, respectively) and mechanosensory array morphology (planar vs. 3D, respectively). When exposed to these vortex flow treatments, T. longicornis exhibited a minimal behavioral response to the Level 2 vortex, but significantly altered their swimming behavior in the presence of the Level 3 vortex. Specifically, in the Level 3 vortex treatment T. longicornis increased relative swim speed, turn frequency, and escape acceleration while decreasing angle of alignment with the vortex axis and escape frequency (relative to stagnant control conditions). Histograms of escape jump location as a function of radius reveals no preferential escape location for T. longicornis, which contrasts the preferential escape location of A. tonsa in the vortex core.

  13. Microplastic potentiates triclosan toxicity to the marine copepod Acartia tonsa (Dana)

    DEFF Research Database (Denmark)

    Syberg, Kristian; Nielsen, Anne; Khan, Farhan

    2017-01-01

    Microplastics (MP) are contaminants of environmental concern partly due to plastics ability to sorb and transport hydrophobic organic contaminants (HOC). The importance of this “vector effect” is currently being debated in the scientific community. This debate largely ignores that the co-exposure......Microplastics (MP) are contaminants of environmental concern partly due to plastics ability to sorb and transport hydrophobic organic contaminants (HOC). The importance of this “vector effect” is currently being debated in the scientific community. This debate largely ignores that the co......-exposures of MP and HOC are mixtures of hazardous agents, which can be addressed from a mixture toxicity perspective. In this study, mixture effects of polyethylene microbeads (MP) and triclosan (TCS) (a commonly used antibacterial agent in cosmetics) were assessed on the marine copepod Acartia tonsa. Data...

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

    Science.gov (United States)

    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

  15. Copepod swimming behavior, respiration, and expression of stress-related genes in response to high stocking densities

    OpenAIRE

    Nilsson, Birgitte; Jakobsen, Hans H.; Stief, Peter; Drillet, Guillaume; Hansen, Benni W

    2017-01-01

    Using copepod nauplii as live feed in aquaculture hatcheries could solve high mortality rates of first-feeding fish larvae due to malnutrition. However, implementing the use of copepod nauplii on an intensive production scale requires a stable production at preferably high densities, which is problematic for calanoid copepod species like Acartia tonsa. In the present study, we evaluated the response of copepods experiencing stress under high-density conditions by assessing the acute stress le...

  16. Distribution and ecophysiology of calanoid copepods in relation to the oxygen minimum zone in the eastern tropical atlantic.

    Directory of Open Access Journals (Sweden)

    Lena Teuber

    Full Text Available Oxygen minimum zones (OMZs affect distribution patterns, community structure and metabolic processes of marine organisms. Due to the prominent role of zooplankton, especially copepods, in the marine carbon cycle and the predicted intensification and expansion of OMZs, it is essential to understand the effects of hypoxia on zooplankton distribution and ecophysiology. For this study, calanoid copepods were sampled from different depths (0-1800 m at eight stations in the eastern tropical Atlantic (3 °47'N to 18 °S during three expeditions in 2010 and 2011. Their horizontal and vertical distribution was determined and related to the extent and intensity of the OMZ, which increased from north to south with minimum O2 concentrations (12.7 µmol kg(-1 in the southern Angola Gyre. Calanoid copepod abundance was highest in the northeastern Angola Basin and decreased towards equatorial regions as well as with increasing depth. Maximum copepod biodiversity was observed in the deep waters of the central Angola Basin. Respiration rates and enzyme activities were measured to reveal species-specific physiological adaptations. Enzyme activities of the electron transport system (ETS and lactate dehydrogenase (LDH served as proxies for aerobic and anaerobic metabolic activity, respectively. Mass-specific respiration rates and ETS activities decreased with depth of occurrence, consistent with vertical changes in copepod body mass and ambient temperature. Copepods of the families Eucalanidae and Metridinidae dominated within the OMZ. Several of these species showed adaptive characteristics such as lower metabolic rates, additional anaerobic activity and diel vertical migration that enable them to successfully inhabit hypoxic zones.

  17. 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...... 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...

  18. Effect of alternative mediums on production and proximate composition of the microalgae Chaetoceros muelleri as food in culture of the copepod Acartia sp.

    OpenAIRE

    Martínez-Córdova,Luis R; Campaña-Torres,Alfredo; Martinez-Porchas,Marcel; López-Elías,José A; García-Sifuentes,Celia O

    2012-01-01

    Microalgae Chaetoceros muelleri was cultured in three different mediums consisting on an agricultural fertilizer (Agr-F), aquacultural fertilizer (Aq-F) and a conventional medium (F/2, control). These microalgae were later used as natural food to culture the copepod Acartia sp. The productive response and chemical proximate composition of microalgae and copepods were monitored. Growth rate and final cell concentration were higher in microalgae cultured in Agr-F compared to the control. In add...

  19. Toxicity of some heavy metals to copepods Acartia spinicauda and Tortanus forcipatus

    Digital Repository Service at National Institute of Oceanography (India)

    Madhupratap, M.; Achuthankutty, C.T.; Nair, S.R.S.

    Copper was most toxic to the species tested followed by cadmium and zinc The estuarine species Acartia spinicauda was more sensitive to the toxicants that the marine species Tortanus forcipatus The 48 hr LC50 values are presented....

  20. Seasonal dynamics of reproductive parameters of the calanoid copepods Calanus helgolandicus and Calanoides carinatus in the Cantabrian Sea (SW Bay of Biscay)

    Science.gov (United States)

    Ceballos, Sara; Álvarez-Marqués, Florentina

    2006-07-01

    The seasonal reproductive dynamics of the calanoid copepods Calanus helgolandicus and Calanoides carinatus and the main driving factors that control their reproductive activity were evaluated through a three-year study performed at two shelf stations in the Cantabrian Sea (SW Bay of Biscay). As a general pattern, the seasonal dynamics showed two peaks of reproduction for both species: the highest peak was associated with the spring phytoplankton bloom, whereas a second and less intense peak coincided with the autumn bloom. Between these two blooms, copepod recruitment showed low rates, and the lowest reproductive activity was recorded in winter. Gonads started to mature in pre-bloom conditions, probably fuelled by stored lipids and concurrent feeding, but the highest RIs (Reproductive Index) and EPRs (egg production rates) were found during the spring blooms. Accordingly feeding seems to be crucial for the main recruitment event for both species. Temperature, Chlorophyll-a (Chl-a) concentration and diatom abundance explained part of the variability found in reproductive activity, with the phytoplankton biomass as the most relevant environmental factor. Temperature probably had an indirect effect on fecundity; temperature and female size were inversely correlated, and large females produced larger clutch sizes. The food assemblage seemed to be more adequate for egg hatching success (HS) than for EPR, because HS was high most of the time, but EPRs were often lower than maximum production rates, pointing to a food limitation. However, the nauplius production rates compared well with those in other areas with higher phytoplankton productivity. Interestingly, a trade-off between number of eggs produced and their viability was found; small clutch sizes with high viability were produced during inadequate food conditions. This strategy maximizes naupliar survival under short food resources by investing in egg quality rather than in quantity. The annual cycle and

  1. Feeding activity of the copepod Acartia hongi on phytoplankton and micro-zooplankton in Gyeonggi Bay, Yellow Sea

    Science.gov (United States)

    Yang, Eun Jin; Ju, Se-Jong; Choi, Joong-Ki

    2010-06-01

    To improve our understanding of the trophic link between micro-zooplankton and copepods in Gyeonggi Bay, Yellow Sea, the diet composition, ingestion rates, and prey selectivity of Acartia hongi, known as the most abundant and widespread copepod species, was estimated by conducting in situ bottle incubation throughout the different seasons. The results showed that A. hongi preferentially grazed on ciliate and heterotrophic dinoflagellate of a size ranging from 20 to 100 μm rather than phytoplankton. Although micro-zooplankton comprised only an average 13.7% of the total carbon available in the natural prey pool, micro-zooplankton accounted for >70% of the total carbon ration ingested by A. hongi throughout the year, except for winter diatom blooming periods when A. hongi obtained about 60% of its carbon ration from phytoplankton. Our results demonstrated that A. hongi modified their diet composition and feeding rates in response to change in composition and size of prey available to them, and that A. hongi preferentially ingested micro-zooplankton over phytoplankton. Feeding activity of A. hongi could therefore affect the species composition and size structure of natural plankton communities in this study area, particularly the micro-zooplankton. Strongly selective feeding and high grazing pressure by A. hongi on micro-zooplankton shows the role of trophic coupling between copepods and the microbial food web in the pelagic ecosystem of Gyeonggi Bay.

  2. Influence of two different green algal diets on specific dynamic action and incorporation of carbon into biochemical fractions in the copepod Acartia tonsa

    DEFF Research Database (Denmark)

    Thor, P.; Cervetto, G.; Besiktepe, S.

    2002-01-01

    Previous studies have shown that the two green algae Tetraselmis sp. (Prasinophyceae) and Dunaliella tertiolecta (Chlorophyceae) induce high and low egg production rates in Acartia tonsa. The primary goal of the present study was to investigate if this is attributable to differences in the specific....... The incorporation of carbon into lipids was significantly higher on D. tertiolecta. However, because of lack of longer chain fatty acids in D. tertiolecta the copepods did not benefit from this. Thus, the proportion of carbon allocated to egg lipids was much lower than when feeding on T. impellucida. Acartia tonsa...

  3. 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

    April to August 1999. Vertical and horizontal distribution patterns appeared to be linked with each other and were primarily species-dependent. Both Acartia spp. and Temora longicornis preferentially inhabited the upper 30 m of the water column and the shallower marginal regions of the Bornholm Basin...

  4. 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

  5. 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. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

  6. 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...... of the PSI revealed that it is a nutritionally poor food lacking essential fatty acids, and hence it cannot be used alone to raise copepods but instead as a food additive. This is the first demonstration that the effectiveness of copepod culturing can be improved using microbial preparations as a food...

  7. Toxic effects of polyethylene terephthalate microparticles and Di(2-ethylhexyl)phthalate on the calanoid copepod, Parvocalanus crassirostris.

    Science.gov (United States)

    Heindler, Franz M; Alajmi, Fahad; Huerlimann, Roger; Zeng, Chaoshu; Newman, Stephen J; Vamvounis, George; van Herwerden, Lynne

    2017-07-01

    Large amounts of plastic end up in the oceans every year where they fragment into microplastics over time. During this process, microplastics and their associated plasticizers become available for ingestion by different organisms. This study assessed the effects of microplastics (Polyethylene terephthalate; PET) and one plasticizer (Di(2-ethylhexyl)phthalate; DEHP) on mortality, productivity, population sizes and gene expression of the calanoid copepod Parvocalanus crassirostris. Copepods were exposed to DEHP for 48h to assess toxicity. Adults were very healthy following chemical exposure (up to 5120µg L-1), whereas nauplii were severely affected at very low concentrations (48h LC50value of 1.04 ng L-1). Adults exposed to sub-lethal concentrations of DEHP (0.1-0.3µg L-1) or microplastics (10,000-80,000 particles mL-1) exhibited substantial reductions in egg production. Populations were exposed to either microplastics or DEHP for 6 days with 18 days of recovery or for 24 days. Populations exposed to microplastics for 24 days significantly depleted in population size (60±4.1%, pplastic and DEHP treatments after 6 days of exposure, but not after 18 days of recovery. Hsp70-like expression showed to be unresponsive to either DEHP or microplastic exposure. Clearly, microplastics and plasticizers pose a serious threat to zooplankton and potentially to higher trophic levels. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Effects of Temperature, Salinity, pH, and Light on Filtering and Grazing Rates of a Calanoid Copepod (Schmackeria dubia

    Directory of Open Access Journals (Sweden)

    Changling Li

    2008-01-01

    Full Text Available Calanoid copepods are key components of the marine food web and the food sources of many larval fishes and planktivores, and grazers of phytoplankton. Understanding the ranges of major environmental variables suitable for their growth is essential to maintain the balance between trophic links and resources protection. In this study, the effects of temperature, salinity, pH, and light intensity on the filtering and grazing rates of a herbivorous copepod (Schmackeria dubia were conducted in several control experiments. Our results indicated that experimental animals grazed normally at water temperatures between 15 and 35°C. The filtering and grazing rates increased by onefold at water temperatures from 15 to 25°C, with a peak at around 30°C. S. dubia fed normally at salinity ranging from 20 to 30 ppt, with significantly low filtering and grazing rates at salinity below 15 ppt and above 35 ppt. The filtering and grazing rates increased as pH increased, peaked at approximately 8.5, and then decreased substantially. Light intensity also displayed an important impact on the filtering and grazing rates. Filtering and grazing rates were high when light intensity was greater than 20 and less than 200 µmol m-2 s-1. S. dubia nearly stopped feeding at low light intensity (less than 20 µmol m-2 s-1.

  9. Testing lagoonal sediments with early life stages of the copepod Acartia tonsa (Dana): An approach to assess sediment toxicity in the Venice Lagoon.

    Science.gov (United States)

    Picone, Marco; Bergamin, Martina; Delaney, Eugenia; Ghirardini, Annamaria Volpi; Kusk, Kresten Ole

    2018-01-01

    The early-life stages of development of the calanoid copepod Acartia tonsa from egg to copepodite I is proposed as an endpoint for assessing sediment toxicity by exposing newly released eggs directly onto the sediment-water interface. A preliminary study of 5 sediment samples collected in the lagoon of Venice highlighted that the larval development rate (LDR) and the early-life stages (ELS) mortality endpoints with A. tonsa are more sensitive than the standard amphipod mortality test; moreover LDR resulted in a more reliable endpoint than ELS mortality, due to the interference of the sediment with the recovery of unhatched eggs and dead larvae. The LDR data collected in a definitive study of 48 sediment samples from the Venice Lagoon has been analysed together with the preliminary data to evaluate the statistical performances of the bioassay (among replicate variance and minimum significant difference between samples and control) and to investigate the possible correlation with sediment chemistry and physical properties. The results showed that statistical performances of the LDR test with A. tonsa correspond with the outcomes of other tests applied to the sediment-water interface (Strongylocentrotus purpuratus embryotoxicity test), sediments (Neanthes arenaceodentata survival and growth test) and porewater (S. purpuratus); the LDR endpoint did, however, show a slightly higher variance as compared with other tests used in the Lagoon of Venice, such as 10-d amphipod lethality test and larval development with sea urchin and bivalves embryos. Sediment toxicity data highlighted the high sensitivity and the clear ability of the larval development to discriminate among sediments characterized by different levels of contamination. The data of the definitive study evidenced that inhibition of the larval development was not affected by grain-size and the organic carbon content of the sediment; in contrast, a strong correlation between inhibition of the larval development

  10. 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...

  11. 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...

  12. Copepod swimming behavior, respiration, and expression of stress-related genes in response to high stocking densities

    DEFF Research Database (Denmark)

    Nilsson, Birgitte; Jakobsen, Hans; Stief, Peter

    2017-01-01

    Using copepod nauplii as live feed in aquaculture hatcheries could solve high mortality rates of first-feeding fish larvae due to malnutrition. However, implementing the use of copepod nauplii on an intensive production scale requires a stable production at preferably high densities, which...... is problematic for calanoid copepod species like Acartia tonsa. In the present study, we evaluated the response of copepods experiencing stress under high-density conditions by assessing the acute stress level of A. tonsa. Control density was at 100 ind. L−1 while the treatments were increased stepwise up to 10...

  13. First genetic quantification of sex- and stage-specific feeding in the ubiquitous copepod Acartia tonsa

    DEFF Research Database (Denmark)

    Ismar, Stefanie M.H.; Kottmann, Johanna Sarah; Sommer, Ulrich

    2018-01-01

    assessment. In triplicated mixed-diet feeding treatments, three suitable A. tonsa diets, the cryptophyte Rhodomonas balthica, the haptophyte Isochrysis galbana, and the diatom Thalassiosira weissflogii, were offered in equal biomass proportions under constant conditions. Prey uptake substantially varied...... between different algal species, as did the extent of sex- and stage-specificity of prey uptake. Male adult copepods had higher R. balthica gut contents than females, and nauplii contained more of this prey source than copepodites or adult copepods in mixed treatments. A trend towards higher amounts...

  14. First feeding of Eugerres brasilianus (Carapeva larvae with Acartia tonsa (Copepod nauplii increases survival and resistance to acute stress

    Directory of Open Access Journals (Sweden)

    Wanessa de Melo Costa

    2016-01-01

    Full Text Available The rotifer Brachionus sp. is commonly used for larval feeding in marine fish hatcheries. The aim of this study was to evaluate whether the inclusion of Acartia tonsa nauplii in the initial diet of carapeva larvae improves their survival, growth and resistance to stress when compared to the regimen containing only rotifers. Adult copepods were collected in the wild and cultured with the microalgae Chaetoceros muelleri, Isochrysis galbana and Nannochloropsis oculata to obtain nauplii. Carapeva larvae were grown for 15 days using four treatments and three replicates: 1 Brachionus plicatilis rotifers (10 to 15/mL; 2 A. tonsa nauplii (0.25 to 0.5/mL; 3 Brachionus plicatilis rotifers (5 to 7.5/mL + A. tonsa nauplii (0.12 to 0.25/mL, and 4 no supply of live feed. After 15 days, the carapeva larvae were subjected to stress by exposure to air for 10 seconds and then returned to the source tank to evaluate survival after 24 h. Survival and stress resistance were higher in carapeva larvae fed B. plicatilis + A. tonsa nauplii (P<0.05, 20.9 ± 11.2% and 88.9%, respectively. These results confirm the positive effect of the inclusion of copepod nauplii in the diet of fish larvae. However, more research is needed to validate these results.

  15. Food size spectra, ingestion and growth of the copepod Acartia tonsa during development: implications for the determination of copepod production

    DEFF Research Database (Denmark)

    Berggren, U.; Hansen, B.; Kiørboe, Thomas

    1988-01-01

    size spectra were normalized (percent of maximum clearance in a particular stage versus particle diameter/prosome length) they resembled log-normal distributions with near constant width (variance). Optimum, relative particle sizes corresponded to 2 to 5% of prosome length independent of developmental...... availability is similar for all developmental stages, and that juvenile and female specific growth/egg-production rates are equal, female egg-production rates are representative of turnover rates (production/biomass) of the entireA. tonsa population and probably in other copepod species as well. Therefore...

  16. 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...

  17. 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

    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...

  18. 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.

  19. Inclusion of copepod Acartia tonsa nauplii in the feeding of Centropomus undecimalis larvae increases stress resistance

    Directory of Open Access Journals (Sweden)

    Wanessa de Melo-Costa

    2015-09-01

    Full Text Available This research represents the first result of studies of the common snook Centropomus undecimalis larvae from broodstock matured in captivity in Brazil. The aim of this study was to evaluate if the inclusion of Acartia tonsa nauplii improves stress resistance of common snook larvae. The larvae were fed with: rotifers Brachionus plicatilis (10 to 15 mL-1; A. tonsa nauplii (0.25 to 0.5 mL-1 and rotifers (5 to 7.5 mL-1, and A. tonsa nauplii (0.12 to 0.25 mL-1. The average percentage of survival of the treatments was 11.9%. At 20 days of age, larvae were subjected to thermal stress. Subsequently, the stress resistance was evaluated. Common snook larvae fed B. plicatilis+A. tonsa reached a higher weight and length (7.5 ± 0.00 mg and 9.1 ± 0.23 mm, respectively and resisted more heat stress (87.4% than larvae fed other foods, indicating that the feed mixture is satisfactory as a starter diet for larvae of common snook. However, more research is needed to confirm these results.

  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

    produce diapause eggs requiring a long refractory phase. Delayed hatching eggs (DHE; maternally determined oligopause eggs hatching within > 72 h to a month) have been described as a state between diapause and subitaneous (hatching within 24–72 h) because of their very short refractory phase. We used...... consumption rate, embryogenesis took place with unpredicted rates and most eggs eventually hatched. Based on our observations and theoretical considerations we suggest that DHE follow a U shape metabolism pattern with time as described for true diapause eggs. DHE strategy (oligopause) is an important life...

  1. Rapid adaptation to oil exposure in the cosmopolitan copepod Acartia tonsa

    DEFF Research Database (Denmark)

    Krause, K. E.; Dinh, Khuong Van; Nielsen, Torkel Gissel

    Oil spills are potential environmental hazards to marine ecosystems worldwide. Oil spills may persist in seawater longer than one generation of many zooplankton species. However, whether populations of short-lived and fast growing marine organisms adapt to oil exposure through natural selection...... 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...... that populations of short-lived and fast-growing copepods have the potential of showing surprisingly strong resilience to the type of oil contamination they might face in their natural coastal habitats...

  2. No evidence for induction or selection of mutant sodium channel expression in the copepod Acartia husdsonica challenged with the toxic dinoflagellate Alexandrium fundyense.

    Science.gov (United States)

    Finiguerra, Michael; Avery, David E; Dam, Hans G

    2014-09-01

    Some species in the dinoflagellate genus Alexandrium spp. produce a suite of neurotoxins that block sodium channels, known as paralytic shellfish toxins (PST), which have deleterious effects on grazers. Populations of the ubiquitous copepod grazer Acartia hudsonica that have co-occurred with toxic Alexandrium spp. are better adapted than naïve populations. The mechanism of adaptation is currently unknown. We hypothesized that a mutation in the sodium channel could account for the grazer adaptation. We tested two hypotheses: (1) Expression of the mutant sodium channel could be induced by exposure to toxic Alexandrium fundyense; (2) in the absence of induction, selection exerted by toxic A. fundyense would favor copepods that predominantly express the mutant isoform. In the copepod A. hudsonica, both isoforms are expressed in all individuals in varying proportions. Thus, in addition to comparing expression ratios of wild-type to mutant isoforms for individual copepods, we also partitioned copepods into three groups: those that predominantly express the mutant (PMI) isoform, the wild-type (PWI) isoform, or both isoforms approximately equally (EI). There were no differences in isoform expression between individuals that were fed toxic and nontoxic food after three and 6 days; induction of mutant isoform expression did not occur. Furthermore, the hypothesis that mutant isoform expression responds to toxic food was also rejected. That is, no consistent evidence showed that the wild-type to mutant isoform ratios decreased, or that the relative proportion of PMI individuals increased, due to the consumption of toxic food over four generations. However, in the selected line that was continuously exposed to toxic food sources, egg production rate increased, which suggested that adaptation occurred but was unrelated to sodium channel isoform expression.

  3. Influence of swimming behavior of copepod nauplii on feeding of larval turbot (Scophthalmus maximus)

    DEFF Research Database (Denmark)

    Bruno, Eleonora; Højgaard, Jacob Kring; Hansen, Benni Winding

    2017-01-01

    Feeding in larval fish is influenced by a range of factors and among these are the morphological and behavioral characteristics of their prey. We investigated the influence of the swimming behavior of two species of calanoid copepods, Acartia tonsa and Temora longicornis, on larval turbot feeding....... The nauplii of these species represent two contrasting swimming behaviors: A. tonsa is a jump-sink type swimmer, while T. longicornis is a cruise swimming type. Three replicates of ten larvae aged 7 and 9 days post hatch (DPH) were observed feeding on one of the two copepod species using a 2-dimensional video...

  4. Determining the Advantages, Costs, and Trade-Offs of a Novel Sodium Channel Mutation in the Copepod Acartia hudsonica to Paralytic Shellfish Toxins (PST)

    Science.gov (United States)

    Finiguerra, Michael; Avery, David E.; Dam, Hans G.

    2015-01-01

    The marine copepod Acartia hudsonica was shown to be adapted to dinoflagellate prey, Alexandrium fundyense, which produce paralytic shellfish toxins (PST). Adaptation to PSTs in other organisms is caused by a mutation in the sodium channel. Recently, a mutation in the sodium channel in A. hudsonica was found. In this study, we rigorously tested for advantages, costs, and trade-offs associated with the mutant isoform of A. hudsonica under toxic and non-toxic conditions. We combined fitness with wild-type: mutant isoform ratio measurements on the same individual copepod to test our hypotheses. All A. hudsonica copepods express both the wild-type and mutant sodium channel isoforms, but in different proportions; some individuals express predominantly mutant (PMI) or wild-type isoforms (PWI), while most individuals express relatively equal amounts of each (EI). There was no consistent pattern of improved performance as a function of toxin dose for egg production rate (EPR), ingestion rate (I), and gross growth efficiency (GGE) for individuals in the PMI group relative to individuals in the PWI expression group. Neither was there any evidence to indicate a fitness benefit to the mutant isoform at intermediate toxin doses. No clear advantage under toxic conditions was associated with the mutation. Using a mixed-diet approach, there was also no observed relationship between individual wild-type: mutant isoform ratios and among expression groups, on both toxic and non-toxic diets, for eggs produced over three days. Lastly, expression of the mutant isoform did not mitigate the negative effects of the toxin. That is, the reductions in EPR from a toxic to non-toxic diet for copepods were independent of expression groups. Overall, the results did not support our hypotheses; the mutant sodium channel isoform does not appear to be related to adaptation to PST in A. hudsonica. Other potential mechanisms responsible for the adaptation are discussed. PMID:26075900

  5. Determining the Advantages, Costs, and Trade-Offs of a Novel Sodium Channel Mutation in the Copepod Acartia hudsonica to Paralytic Shellfish Toxins (PST.

    Directory of Open Access Journals (Sweden)

    Michael Finiguerra

    Full Text Available The marine copepod Acartia hudsonica was shown to be adapted to dinoflagellate prey, Alexandrium fundyense, which produce paralytic shellfish toxins (PST. Adaptation to PSTs in other organisms is caused by a mutation in the sodium channel. Recently, a mutation in the sodium channel in A. hudsonica was found. In this study, we rigorously tested for advantages, costs, and trade-offs associated with the mutant isoform of A. hudsonica under toxic and non-toxic conditions. We combined fitness with wild-type: mutant isoform ratio measurements on the same individual copepod to test our hypotheses. All A. hudsonica copepods express both the wild-type and mutant sodium channel isoforms, but in different proportions; some individuals express predominantly mutant (PMI or wild-type isoforms (PWI, while most individuals express relatively equal amounts of each (EI. There was no consistent pattern of improved performance as a function of toxin dose for egg production rate (EPR, ingestion rate (I, and gross growth efficiency (GGE for individuals in the PMI group relative to individuals in the PWI expression group. Neither was there any evidence to indicate a fitness benefit to the mutant isoform at intermediate toxin doses. No clear advantage under toxic conditions was associated with the mutation. Using a mixed-diet approach, there was also no observed relationship between individual wild-type: mutant isoform ratios and among expression groups, on both toxic and non-toxic diets, for eggs produced over three days. Lastly, expression of the mutant isoform did not mitigate the negative effects of the toxin. That is, the reductions in EPR from a toxic to non-toxic diet for copepods were independent of expression groups. Overall, the results did not support our hypotheses; the mutant sodium channel isoform does not appear to be related to adaptation to PST in A. hudsonica. Other potential mechanisms responsible for the adaptation are discussed.

  6. Isolation and Characterization of Bacteria Colonizing Acartia tonsa Copepod Eggs and Displaying Antagonist Effects against Vibrio anguillarum, Vibrio alginolyticus and Other Pathogenic Strains

    Directory of Open Access Journals (Sweden)

    Mahammed Zidour

    2017-10-01

    Full Text Available Copepods represent a major source of food for many aquatic species of commercial interest for aquaculture such as mysis shrimp and early stages of fishes. For the purpose of this study, the culturable mesophilic bacterial flora colonizing Acartia tonsa copepod eggs was isolated and identified. A total of 175 isolates were characterized based on their morphological and biochemical traits. The majority of these isolates (70% were Gram-negative bacteria. Matrix-assisted laser desorption/ionization-time of flight-mass spectrometry (MALDI-TOF-MS was used for rapid identification of bacterial isolates. Here, 58% of isolates were successfully identified at the genus level and among them, 54% were identified at the species level. These isolates belong to 12 different genera and 29 species. Five strains, identified as Bacillus pumilus, named 18 COPS, 35A COPS, 35R COPS, 38 COPS, and 40A COPS, showed strong antagonisms against several potential fish pathogens including Vibrio alginolyticus, V. anguillarum, Listeria monocytogenes, and Staphylococcus aureus. Furthermore, using a differential approach, we show that the antimicrobial activity of the 35R COPS strain is linked primarily to the production of antimicrobial compounds of the amicoumacin family, as demonstrated by the specific UV-absorbance and the MS/MS fragmentation patterns of these compounds.

  7. 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

    To meet the oncoming requirements for lower sulphur emissions, shipping companies can install scrubbers where the exhaust is sprayed with seawater and subsequently discharged to the sea. The discharge water has a pH around 3 and contains elevated concentrations of vanadium, nickel, lead and hydro......To meet the oncoming requirements for lower sulphur emissions, shipping companies can install scrubbers where the exhaust is sprayed with seawater and subsequently discharged to the sea. The discharge water has a pH around 3 and contains elevated concentrations of vanadium, nickel, lead...... 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...

  8. A new large egg type from the marine live feed calanoid copepo Acartia tonsa (Dana) - Perspectives for selective breeding of designer feed for hatcheries

    DEFF Research Database (Denmark)

    Halsen Hammervold, Stian; Glud, Ronnie N.; Evjemo, Jan Ove

    2015-01-01

    Mass cultivation of marine copepods as live feed requires predictable and uniform production of a standard product for the end users, the hatcheries. A previously undescribed large egg type, measuring a mean diameter of 106.5 μm, was characterized and compared to normal eggs (82.3 μm) from...

  9. 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.

  10. Ocean acidification challenges copepod phenotypic plasticity

    Directory of Open Access Journals (Sweden)

    A. Vehmaa

    2016-11-01

    Full Text Available 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. 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.

  12. Feeding behaviour of the nauplii of the marine calanoid copepod Paracartia grani Sars: Functional response, prey size spectrum, and effects of the presence of alternative prey.

    Directory of Open Access Journals (Sweden)

    Laura K Helenius

    Full Text Available Laboratory feeding experiments were conducted to study the functional response and prey size spectrum of the young naupliar stages of the calanoid copepod Paracartia grani Sars. Experiments were conducted on a range of microalgal prey of varying sizes and motility patterns. Significant feeding was found in all prey of a size range of 4.5-19.8 μm, with Holling type III functional responses observed for most prey types. The highest clearance rates occurred when nauplii fed on the dinoflagellate Heterocapsa sp. and the diatom Thalassiosira weissflogii (respectively, 0.61 and 0.70 mL ind-1 d-1, suggesting an optimal prey:predator ratio of 0.09. Additional experiments were conducted to examine the effects of the presence of alternative prey (either Heterocapsa sp. or Gymnodinium litoralis on the functional response to the haptophyte Isochrysis galbana. In the bialgal mixtures, clearance and ingestion rates of I. galbana along the range of the functional response were significantly reduced as a result of selectivity towards the larger, alternative prey. Paradoxically, relatively large prey trigger a perception response in the nauplii, but most likely such prey cannot be completely ingested and a certain degree of sloppy feeding may occur. Our results are further evidence of the complex prey-specific feeding interactions that are likely to occur in natural assemblages with several available prey types.

  13. Effects of low pH and raised temperature on egg production, hatching and metabolic rates of a Mediterranean copepod species (Acartia clausi under oligotrophic conditions

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    S. ZERVOUDAKI

    2013-09-01

    Full Text Available This study includes the first information on the combined effect of low pH and raised temperature on egg production rate (EP, hatching success (HS, excretion and respiration of the Mediterranean copepod Acartia clausi. Adult individuals of A. clausi and fresh surface seawater were collected at a coastal station in Saronikos Gulf during April 2012. Four different conditions were applied: two different pH levels (present: 8.09 and future: 7.83 at two temperature values (present: 16°C and present+4 °C= 20°C. EP and HS success decreased significantly over the duration of exposure at future pH at both temperature conditions. However, the analysis of the combined effect of pH, T, chlorophyll α and the duration of the experiments on EP and HS revealed that ocean acidification had no discernible effect, whereas warming; food and the duration of exposure were more significant for the reproductive output of A. clausi. Temperature appeared to have a positive effect on respiration and excretion. Acidification had no clear effect on respiration, but a negative effect on the A. clausi excretion was observed. Acidification and warming resulted in the increase of the excretion rate and the increase was higher than that observed by warming only. Our findings showed that a direct effect of ocean acidification on copepod’s vital rates was not obvious, except maybe in the case of excretion. Therefore, the combination of acidification with the ambient oligotrophic conditions and the warming could result in species being less able to allocate resources for coping with multiple stressors.

  14. 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...

  15. Influence of swimming behavior of copepod nauplii on feeding of larval turbot (Scophthalmus maximus)

    DEFF Research Database (Denmark)

    Bruno, Eleonora; Højgaard, Jacob Kring; Hansen, Benni Winding

    2017-01-01

    Feeding in larval fish is influenced by a range of factors and among these are the morphological and behavioral characteristics of their prey. We investigated the influence of the swimming behavior of two species of calanoid copepods, Acartia tonsa and Temora longicornis, on larval turbot feeding...... feeding on T. longicornis (54%). We conclude that the differences between behavior and other characteristics of these prey species have only minor effect on larval fish feeding, suggesting that copepods species for live feed should be selected according to their ease to culture more than to their species....... The nauplii of these species represent two contrasting swimming behaviors: A. tonsa is a jump-sink type swimmer, while T. longicornis is a cruise swimming type. Three replicates of ten larvae aged 7 and 9 days post hatch (DPH) were observed feeding on one of the two copepod species using a 2-dimensional video...

  16. Ocean acidification challenges copepod reproductive plasticity

    Science.gov (United States)

    Vehmaa, A.; Almén, A.-K.; Brutemark, A.; Paul, A.; Riebesell, U.; Furuhagen, S.; Engström-Öst, J.

    2015-11-01

    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 bifilosa 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 if 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 copepod size and egg hatching success. In addition, we found a threshold of fCO2 concentration (~ 1000 μatm), 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 A. bifilosa could be affected by projected near future CO2 levels.

  17. Effect of alternative mediums on production and proximate composition of the microalgae Chaetoceros muelleri as food in culture of the copepod Acartia sp. Efecto de medios alternativos sobre la producción y composición proximal de la microalga Chaetoceros muelleri como alimento en cultivo del copépodo Acartia sp.

    Directory of Open Access Journals (Sweden)

    Luis R Martínez-Córdova

    2012-03-01

    Full Text Available Microalgae Chaetoceros muelleri was cultured in three different mediums consisting on an agricultural fertilizer (Agr-F, aquacultural fertilizer (Aq-F and a conventional medium (F/2, control. These microalgae were later used as natural food to culture the copepod Acartia sp. The productive response and chemical proximate composition of microalgae and copepods were monitored. Growth rate and final cell concentration were higher in microalgae cultured in Agr-F compared to the control. In addition, the final biomass and cellular concentration were also the highest in Agr-F. Microalgae from Agr-F and Aq-F had higher carbohydrate and lower protein contents than those in the control. No differences in lipid and ash contents were observed. Regarding copepod production, higher densities and fecundity indexes were observed for those fed with microalgae previously cultured in Agr-F and Aq-F, compared to the control. The adult-nauplii ratio was also higher in copepods fed on microalgae from Agr-F compared to Aq-F and control. Copepods fed on Agr-F and Aq-F microalgae, had higher protein content compared to those fed on control microalgae; carbohydrates were higher in copepods fed on Agr-F as compared to Aq-F microalgae. No differences in lipid and ash contents were registered. Agr-F and Aq-F were adequate alternative mediums to produce C. muelleri, which produced higher quality microalgae that increased the copepod production.La microalga Chaetoceros muelleri fue cultivada en tres medios diferentes basados en un fertilizante agrícola (Agr-F, un fertilizante acuícola (Aq-F y un medio convencional (F/2, control. Éstas microalgas fueron posteriormente utilizadas como alimento natural para cultivar el copépodo Acartia sp. La respuesta productiva y la composición proximal de las microalgas y copépodos fueron monitoreadas. La tasa de crecimiento y concentración final de células fueron mayores en la microalga cultivada en Agr-F, comparada con el control

  18. Can we use laboratory reared copepods for experiments - a comparison of feeding behavior and reproduction between a field and a laboratory population of Acartia tonsa

    DEFF Research Database (Denmark)

    Tiselius, P.; Hansen, B.; Jonsson, P.

    1995-01-01

    Motility patterns and egg production were investigated in two populations of Acartia tonsa, field animals from the Oresund and laboratory animals from a 12-year-old (approximate to 120 generations) culture. When observed in aquaria with a layer of Thalassiosira weissflogii in the middle, laboratory...... animals displayed weak aggregation behaviour, while field animals did not aggregate at all. Both populations made longer and more frequent feeding bouts inside the patch. Egg production measurements were in accordance with the behaviour of the laboratory population if no diel feeding rhythm was assumed...... differed considerably from held-caught A. tonsa from the eastern United States, where both behaviour and egg production changed consistently and in accordance with a strong aggregation in food patches. (C) 1995 International Council for the Exploration of the Sea...

  19. 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

    .2%, combined with an estimated protein content of 57% of dry weight for adult females. Both the fatty and amino acid profiles show favourable nutritional values towards fish larvae rearing. Further investigation into P. annandalei's potential biosynthetic capabilities and intake of particles other than pelagic....... The copepods, as well as seston, were sampled from outdoor large-scale aquaculture ponds in southern Taiwan during a three week period in the summer, and their somatic biomass, fatty acid and amino acid profiles were examined. The resulting fatty acid profiles of the copepods and pond seston were compared...... possible fatty acid chain alteration mechanisms and/or alternative dietary input. Frequent addition of different types of meal and manure by the farmers, in order to stimulate productivity in the ponds, may provide adults with additional fatty acids that are not found in the pond seston. Also, amino acid...

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

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    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

  1. 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

  2. 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

    that the temperature-dependent viscosity of seawater is the key physical/mechanical factor that controls the beat frequency of water-pumping cilia in mussels and the swimming velocity in a ciliate. The present study on the swimming velocity of 3 zooplankton organisms, however, shows that the response of swimming...... velocity to a change in viscosity is different when due to a change in temperature or, at constant temperature, due to a manipulation of viscosity by addition of a high-molecular-weight polymer (polyvinyl pyrrolidone, PVP) to the ambient seawater. There is a biological effect (fraction of total reduction......) 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...

  3. 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...

  4. Do Acartia tonsa (Dana) eggs regulate their volume and osmolality as salinity changes?

    DEFF Research Database (Denmark)

    Hansen, Benni Winding; Drillet, Guillaume; Pedersen, Morten Foldager

    2012-01-01

    at 0 psu and back to its initial volume when gradually being returned to full strength salinity. Egg osmolality followed the molality of the surrounding water when challenged within a salinity range from 2 to 50 psu. Egg respiration was not affected when eggs kept at 35 psu was exposed to low salinity....... In contrast, extreme hyper-saline conditions (76 psu) made the eggs implode and killed the embryo. We propose that the embryo is protected from salinity stress by its plasma membrane and that water exchange driven by osmosis is restricted to the perivitelline space of the egg, which acts as a perfect......Subitaneous eggs from an euryhaline calanoid copepod Acartia tonsa were challenged by changes in salinity within the range from full strength salinity, down to zero and up to >70 psu. Egg volume changed immediately, increasing from 2.8 × 105 μm3 at full strength salinity (35 psu) to 3.8 × 105 μm3...

  5. Feeding preference and daily ration of 12 dominant copepods on mono and mixed diets of phytoplankton, rotifers, and detritus in a tropical coastal water.

    Science.gov (United States)

    Jagadeesan, L; Jyothibabu, R; Arunpandi, N; Anjusha, A; Parthasarathi, S; Pandiyarajan, R S

    2017-09-11

    Results of the experimental studies on the feeding habit and daily ration (DR) of 12 dominant copepods from a tropical coastal water (off Kochi, Southwest coast of India) on different food items (phytoplankton, rotifers, and detritus) are presented. Even though, all species of copepods consumed all types of food items in the experiments, they showed noticeable feeding preferences, having important ecological implications. Calanoid Paracalanus parvus and Acrocalanus gracilis consumed phytoplankton and rotifers equally in mono diets (74-89% of DR) and mixed diets (53-82% of DR), which indicated their ability to shift their diet in natural environment based on the availability of food items. Calanoid Acartia erythraea and A. danae consumed more phytoplankton (DR 83 and 72%, respectively) than rotifers (DR 51 and 46%, respectively) in mono diets, and in mixed diets, their consumption was high in phytoplankton combined food mixtures (P + R DR and P + D DR) rather than the R + D food type, indicated their preference for mixed diets of phytoplankton. Similarly, Calanoid Temora turbinata, Pseudodiaptomus serricaudatus, and Centropages tenuiremis preferred a herbivorous diet as evidenced by their high ingestion rate on phytoplankton mono (70 to 87% to their DR) and mixed diets (58 to 80% of DR). On the other hand, Cyclopoid Oithona similis and Poecilostomatoid Corycaeus danae preferred a carnivorous diet, consuming more rotifers (> 80% of DR) than phytoplankton (18-20% of DR) and detritus (5-6% of DR). Harpacticoids Macrosetella gracilis and Euterpina acutifrons equally preferred phytoplankton (78-92% of DR) and detritus (65-89% of DR). The study showed that the dominant copepods in the coastal waters off Kochi occupy different trophic niches available in the environment, which may be applicable in other similar environments as well.

  6. 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...

  7. The occurrence of Acartia species and their environmental characteristics at three ports in Korea

    Science.gov (United States)

    Kang, Jung-Hoon

    2011-12-01

    This study investigated the occurrence of Acartia copepods and their environmental characteristics to identify the existence and survival of foreign species at domestic ports in Korea. Copepods samples were collected seasonally, and temperature, salinity, dissolved oxygen (DO), total suspended solids (TSS), and chlorophyll- a (chl- a) were measured at the seaports Incheon, Gwangyang, and Ulsan from 2007 to 2009. No foreign species was found and all of the Acartia copepods observed had been recorded in Korean waters previously. Acartia omorii, A. hongi, and A. pacifica were found at all three seaports, whereas portspecific species were found at Incheon ( A. sinjiensis) and Ulsan ( A. steueri, A. negligens, and A. danae). When chl- a and DO were not limited, eurythermal and euryhaline A. hongi, A. omorii, and A. hudsonica occurred at TSS concentrations between 38 and 183 mg·L-1, while warm-water copepods ( A. pacifica, A. ohtsukai, A. sinjiensis, and A. erythraea) occurred at TSS concentrations <80 mg·L-1. The seasonal distributions of A. omorii, A. hongi, and A. pacifica at the three seaports were most significantly explained by temperature, salinity, DO, and TSS, and not chl- a. The variation in A. hudsonica and A. sinjiensis at Incheon was explained mainly by temperature, DO, and TSS, whereas A. erythraea at Ulsan was influenced only by chl- a. The occurrence of Acartia copepods showed spatiotemporal variation as a result of species-specific preferences or tolerances in each port environment. Multiple regression analysis indicated that temperature, salinity, DO, and TSS were better predictors of the variation in Acartia species at the seaports during the study than chl- a when food was not limiting. These results indicated that the occurrence of Acartia copepods and related environmental characteristics are crucial information for differentiating foreign species from the native community and predicting the potential for foreign copepods to become established

  8. Climatic Facilitation of the Colonization of an Estuary by Acartia tonsa

    Science.gov (United States)

    Chaalali, Aurélie; Beaugrand, Grégory; Raybaud, Virginie; Goberville, Eric; David, Valérie; Boët, Philippe; Sautour, Benoit

    2013-01-01

    Global change has become a major driving force of both terrestrial and marine systems. Located at the interface between these two realms, estuarine ecosystems are probably the place where both direct and indirect effects of human activities conspire together to affect biodiversity from phytoplankton to top predators. Among European estuarine systems, the Gironde is the largest estuary of Western Europe and many studies have provided evidence that it has been affected by a variety of anthropogenic stressors such as thermal and chemical pollution, physical alterations and exploitation, especially for maritime traffic. In such a context, species introduction is also a current major issue with the establishment of strong competitive species that could lead to ecosystem reorganization with potential decrease or even disappearance of native species. In the Gironde estuary, this hypothesis was proposed for the invasive shrimp species Palaemon macrodactylus as a decrease in the native species abundance was observed at the same time. Although species introduction often takes place via ballast water, the influence of climate-driven changes on the establishment of new species remains a key issue. The calanoid copepod Acartia tonsa, observed in the Gironde estuary for the first time in 1983, have since colonized most part of the estuary, reaching a level of abundance comparable to the dominant native species Eurytemora affinis. In this study, using both the concept of the ecological niche sensu Hutchinson (fundamental and realized niches) and statistical models, we reveal that the dynamics of the colonization of A. tonsa was facilitated by environmental conditions that have become closer to its environmental optimum with respect to temperature and salinity. PMID:24098656

  9. Do Acartia tonsa (Dana) eggs regulate their volume and osmolality as salinity changes?

    Science.gov (United States)

    Hansen, Benni Winding; Drillet, Guillaume; Pedersen, Morten F; Sjøgreen, Kristian P; Vismann, Bent

    2012-07-01

    Subitaneous eggs from an euryhaline calanoid copepod Acartia tonsa were challenged by changes in salinity within the range from full strength salinity, down to zero and up to >70 psu. Egg volume changed immediately, increasing from 2.8 × 10(5) μm(3) at full strength salinity (35 psu) to 3.8 × 10(5) μm(3) at 0 psu and back to its initial volume when gradually being returned to full strength salinity. Egg osmolality followed the molality of the surrounding water when challenged within a salinity range from 2 to 50 psu. Egg respiration was not affected when eggs kept at 35 psu was exposed to low salinity (2 psu). These results suggest that eggs are unable to regulate their volume or osmolality when challenged with changes in salinity. Gradual changes in salinity from 35 to 2 psu and back did not harm the eggs (embryos), since the hatching success remained unaffected by such changes in salinity. In contrast, extreme hyper-saline conditions (76 psu) made the eggs implode and killed the embryo. We propose that the embryo is protected from salinity stress by its plasma membrane and that water exchange driven by osmosis is restricted to the perivitelline space of the egg, which acts as a perfect osmometer in the salinity range of 5-35 psu. We hypothesize further that the embryo is able to keep its volume and osmolality constant due to the impermeability of the inner plasma membrane of the egg or by a combination of osmoregulation and reduced permeability of the inner plasma membrane.

  10. Embryonic cold storage capability from seven strains of Acartia spp. isolated in different geographical areas

    DEFF Research Database (Denmark)

    Hansen, Benni Winding; Buttino, Isabella; Cunha, Maria Emilia

    2016-01-01

    for embryo storage tolerance caused by the management practice in long term continuous cultures. We conclude that the studied embryos from the genus Acartia can all be stored for different time periods and hence are relevant for being used as regional/local egg banks and further studies for developing future...... practically for establishing an egg bank, where embryos can be kept alive and hatched at a later time. The stored embryos can be shipped to end-users and the hatched nauplii used directly as live feed as well as they can be used to establish new copepod cultures. Acartia tonsa (Dana) is a cosmopolite...... of exogenous species in new environments, it is recommended to cultivate regional or even local species of copepods. In the present contribution we compare the cold storage capacity of embryos produced by seven strains of Acartia spp. isolated from different zoogeographical regions ranging from Northern Europe...

  11. Copepod Behavior in Thin Layers of Toxic Algae

    Science.gov (United States)

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

    2016-02-01

    Cryptic blooms of toxic phytoplankton were modeled in a custom thin layer flume for behavioral assays with calanoid copepods. Acartia tonsa and Temora longicornis were exposed to thin layers of exudates from the toxic dinoflagellate Karenia brevis (1 - 10,000 cells/mL). Planar laser-induced fluorescence (PLIF) was used to quantify the spatial 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 increased swimming speed and swimming speed variability in the exudate layer and post-contact, whereas T. longicornis slightly increased both in-layer and slightly reduced both post-contact. Both species increased turn frequency in-layer and post-contact with increasing K. brevis exudate concentration. Path fractal geometry indicated that A. tonsa trajectories 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 three to fifty times that of T. longicornis depending on the parameter considered. The results suggested that 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. Copepod colonization of natural and artificial substrates in a salt marsh pool

    Science.gov (United States)

    Cummings, Eileen; Ruber, Ernest

    1987-12-01

    Pre-weighed packets of Spartina alterniflora and of plastic (polypropylene) twine were placed in a salt marsh pool and recovered on 40 dates spanning 14 months. New packets were placed out regularly to provide a contrast with ageing material. Twelve species of copepods were extracted, counted, and identified. Dry weight and Kjeldahl-nitrogen were determined for Spartina packets. Eight species of copepods, Amphiascus pallidus, Onychocamptus mohammed, Cletocamptus deitersei, Halicyclops sp., Harpacticus chelifer, Mesochra lilljeborgii, Metis jousseaumei and Nitocra sp. were found in higher densities on old grass or plastic packets than on new. The quantity of material was important in that the relative attractiveness of old grass was much lower early in the second year when 7-15% dw and 0·7% nitrogen remained than early in the first year when over 60% dw and 2·0% nitrogen remained. Old plastic polypropylene was equally or more attractive than old grass to 7 of 8 species, therefore, nitrogen decline in old grass was not the factor making it less attractive. Once aged, the quantity of substrate was more important than its quality. Apparently, this is due to colonization by microflora or settlement of detritus but these were not studied. The four clear exceptions to these trends were Darcythompsonia fairliensis and Eurytemora affinis which showed highest densities 72% and 50% of the time in new grass, Apocyclops spartinus with 70% in grass and equal numbers between old and new packets and Acartia tonsa a bay calanoid with 82% of highest densities in the water column and only two occurrences out of 40 dates in the packets.

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

    NARCIS (Netherlands)

    van Duren, L.A; Stamhuis, E.J; Videler, J.J

    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.

  14. Economic feasibility of copepod production for commercial use

    DEFF Research Database (Denmark)

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

    2015-01-01

    During the last three decades, it has been shown that copepods are a superior live feed for marine finfish larvae compared to other commonly used live feed items, such as Artemia and rotifers. The use of copepods, which have a better biochemical composition, increases survival rate, improves growth...... condition, reduces mal-pigmentation and allows breeding of ‘new’ marine finfish species. However, copepods are not yet commercially produced and therefore not widely used in the aquaculture industry. One of the bottlenecks for large-scale production has been lack of economic knowledge on the feasibility...... 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...

  15. Grazing impact of copepods and salps on phytoplankton in the Atlantic sector of the Southern ocean

    Science.gov (United States)

    Dubischar, Corinna D.; Bathmann, Ulrich V.

    During the SO-JGOFS- Polarstern cruise in October/November 1992, grazing of the dominant calanoid copepods ( Calanoides acutus, Calanus propinquus and Rhincalanus gigas) and of Salpa thompsoni was determined. Calanoides acutus and R. gigas were very abundant in the Polar Frontal region (PFr). Calanus propinquus was abundant at the ACC-Weddell Gyre Boundary (AWB). Grazing by copepods was very low and accounted for less than 1% of the primary production (PP) for all three species. Salpa thompsoni occurred in swarms in the southern part of the Antarctic Circumpolar Current (ACC) where its ingestion rates accounted for more than 100% of the PP. We conclude that grazing by copepods had a negligible effect on build-up of the phytoplankton biomass recorded in the PFr and-to a much lesser extent-at the AWB, whereas high grazing pressure of S. thompsoni was likely to have constrained phytoplankton biomass levels in the ACC.

  16. Calanoid copepods of the International Indian Ocean Expedition

    Digital Repository Service at National Institute of Oceanography (India)

    Stephen, R.; Devi, K.S.; Meenakshikunjamma, P.P.; Gopalakrishnan, T.C.; Saraswathy, M.

    was the most abundant group contributing to 31.09% of the population. Genus Pleuromamma and family Euchaetidae constituted 15% and 13% respectively. Among the more rare taxa, Tortanus was observed in the Bay of Bengal, Pseudodiaptomidae were totally confined...

  17. 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...

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

    NARCIS (Netherlands)

    van Duren, LA; Videler, JJ

    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

  19. Morphometric differences in two calanoid sibling species, Boeckella gracilipes and B. titicacae (Crustacea, Copepoda)

    OpenAIRE

    Patricio de los Ríos Escalante

    2012-01-01

    Calanoid copepods are abundant in South American inland waters and include widespread species, such as Boeckella gracilipes (Daday, 1902), which occurs from the Ecuador to Tierra del Fuego Island. This species occurs under various environmental conditions, and is found in oligotrophic lakes in Patagonia (39-54°S) and in shallow mountain lakes north of 39°S. The aim of the present study is to conduct a morphometric comparison of male specimens of B. titicacae collected in Titicaca and B. graci...

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

    Science.gov (United States)

    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

  1. 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.

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

    DEFF Research Database (Denmark)

    Kiørboe, Thomas

    2006-01-01

    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...... because they have on average a factor of 2 higher egg production rates than other pelagic copepods. Secondly, other copepods require only one mating to stay fertile, and populations of these species have strongly female-skewed adult sex-ratios in field populations. Resting eggs have not been described...... 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...

  3. 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

    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...... to naupliar stages of the planktonic copepods Acartia tonsa, Temora turbinata and Pseudodiaptomus pelagicus. Low concentrations of dispersed crude oil (1 μL L(-1)) caused a significant reduction in survival, growth and swimming activity of copepod nauplii after 48 h of exposure. UVB radiation increased...

  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. 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.

  6. Stable Associations Masked by Temporal Variability in the Marine Copepod Microbiome.

    Directory of Open Access Journals (Sweden)

    Pia H Moisander

    Full Text Available Copepod-bacteria interactions include permanent and transient epi- and endobiotic associations that may play roles in copepod health, transfer of elements in the food web, and biogeochemical cycling. Microbiomes of three temperate copepod species (Acartia longiremis, Centropages hamatus, and Calanus finmarchicus from the Gulf of Maine were investigated during the early summer season using high throughput amplicon sequencing. The most prominent stable component of the microbiome included several taxa within Gammaproteobacteria, with Pseudoalteromonas spp. especially abundant across copepod species. These Gammaproteobacteria appear to be promoted by the copepod association, likely benefitting from nutrient enriched microenvironments on copepods, and forming a more important part of the copepod-associated community than Vibrio spp. during the cold-water season in this temperate system. Taxon-specific associations included an elevated relative abundance of Piscirickettsiaceae and Colwelliaceae on Calanus, and Marinomonas sp. in Centropages. The communities in full and voided gut copepods had distinct characteristics, thus the presence of a food-associated microbiome was evident, including higher abundance of Rhodobacteraceae and chloroplast sequences in the transient communities. The observed variability was partially explained by collection date that may be linked to factors such as variable time since molting, gender differences, and changes in food availability and type over the study period. While some taxon-specific and stable associations were identified, temporal changes in environmental conditions, including food type, appear to be key in controlling the composition of bacterial communities associated with copepods in this temperate coastal system during the early summer.

  7. Seasonal dynamics of Pseudocalanus minutus elongatus and Acartia spp. in the southern Baltic Sea (Gdańsk Deep – numerical simulations

    Directory of Open Access Journals (Sweden)

    L. Dzierzbicka-Głowacka

    2006-01-01

    Full Text Available A population dynamics model for copepods is presented, describing the seasonal dynamics of Pseudocalanus minutus elongatus and Acartia spp. in the southern Baltic Sea (Gdańsk Deep. The copepod model was coupled with a one-dimensional physical and biological upper layer model for nutrients (total inorganic nitrogen, phosphate, phytoplankton, microzooplankton, and an early juvenile of herring as a predator. In this model, mesozooplankton (herbivorous copepods has been introduced as an animal having definite patterns of growth in successive stages, reproduction and mortality. The populations are represented by 6 cohorts in different developmental stages, thus assuming that recruitment of the next generation occurs after a fixed period of adult life. The copepod model links trophic processes and population dynamics, and simulates individual growth within cohorts and the changes in biomass between cohorts. The simulations of annual cycles of copepods contain one complete generation of Pseudocalanus and two generations of Acartia in the whole column water, and indicate the importance of growth in the older stages of 6 cohorts of each species, to arrive at a total population biomass. The peaks of copepods' biomass are larger at the turn of June and July for Pseudocalanus and smaller in July for Acartia, lagging that of phytoplankton by ca. two mouths, due to the growth of cohorts in successive stages and egg production by females. The numerical results show that the investigated species could not be the main factor limiting the spring phytoplankton bloom in the Gdańsk Deep, because the initial development was slow for Acartia and faster for Pseudocalanus, but the main development formed after the bloom, in both cases. The phytoplankton bloom is very important in the diet of the adults of the copepods, but it is not particularly important for the youngest part of new generation (early nauplii. However, the simulated microzooplankton biomass was

  8. 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.

  9. Copepods' Response to Burgers' Vortex: Deconstructing Interactions of Copepods with Turbulence.

    Science.gov (United States)

    Webster, D R; Young, D L; Yen, J

    2015-10-01

    This study examined the behavioral response of two marine copepods, Acartia tonsa and Temora longicornis, to a Burgers' vortex intended to mimic the characteristics of a turbulent vortex that a copepod is likely to encounter in the coastal or near-surface zone. Behavioral assays of copepods were conducted for two vortices that correspond to turbulent conditions with mean dissipation rates of turbulence of 0.009 and 0.096 cm(2) s(-3) (denoted turbulence level 2 and level 3, respectively). In particular, the Burgers' vortex parameters (i.e., circulation and rate of axial strain rate) were specified to match a vortex corresponding to the median rate of dissipation due to viscosity for each target level of turbulence. Three-dimensional trajectories were quantified for analysis of swimming kinematics and response to hydrodynamic cues. Acartia tonsa did not significantly respond to the vortex corresponding to turbulence level 2. In contrast, A. tonsa significantly altered their swimming behavior in the turbulence-level-3 vortex, including increased relative speed of swimming, angle of alignment of the trajectory with the axis of the vortex, ratio of net-to-gross displacement, and acceleration during escape, along with decreased turn frequency (relative to stagnant control conditions). Further, the location of A. tonsa escapes was preferentially in the core of the stronger vortex, indicating that the hydrodynamic cue triggering the distinctive escape behavior was vorticity. In contrast, T. longicornis did not reveal a behavioral response to either the turbulence level 2 or the level 3 vortex. © The Author 2015. Published by Oxford University Press on behalf of the Society for Integrative and Comparative Biology. All rights reserved. For permissions please email: journals.permissions@oup.com.

  10. Non-indigenous zooplankton : the role of predatory cladocerans and of copepods in trophic dynamics

    OpenAIRE

    Andersen Borg, Marc

    2009-01-01

    Human-mediated introductions of non-indigenous species now threaten to homogenize the biota of the Globe, causing huge economic and ecological damage. This thesis studies the ecological role of 3 invasive planktonic crustaceans, the omnivorous copepod Acartia tonsa (western Atlantic and Indo-Pacific) and the predatory cladocerans, Cercopagis pengoi (Ponto-Caspian) and Bythotrephes longimanus (Eurasian). B. longimanus invaded the North American Great Lakes in 1982, C. pengoi the Baltic in 1992...

  11. 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. PMID:22053187

  12. 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.

  13. 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.

  14. The effects of power station entrainment passage on three species of marine planktonic crustacean, Acartia tonsa (Copepoda), Crangon crangon (Decapoda) and Homarus gammarus (Decapoda).

    Science.gov (United States)

    Bamber, Roger N; Seaby, Richard M H

    2004-05-01

    Experiments have been undertaken exposing larval common shrimp (Crangon crangon) and lobster (Homarus gammarus) and adult copepods (Acartia tonsa) to the key stresses of entrainment within power-station cooling-water systems. The apparatus has enabled the testing of mechanical, thermal, chlorine and realistic pressure effects both alone and in combination, the range of stressors spanning the standard conditions found within a temperate coastal direct-cooled power station. Mechanical stresses affected only lobster larvae, pressure changes affected only the Acartia adults. Residual chlorine caused significant mortality of Acartia and shrimp larvae, but had no effect on lobster larvae even at 1 ppm. The temperature increment significantly affected all three species, with a synergistic effect on chlorine sensitivity in the shrimp larvae, but only temperatures higher than would be experienced in a normally-operating power station affected the copepods. The majority of individuals of each species would survive passage through a power-station system under normal conditions. It is notable that, within the species tested, generalizations from the responses of one species to those of another are not valid.

  15. 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.

  16. 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...... distance, but larger prey caused a significantly longer handling time. Post-detection processing of the cells was exceedingly fast. The time from detection to the cell being placed at the mouth lasted 35 ± 19 ms and rejection of unwanted cells 61 ± 21 ms. Grooming of antennules and carapace occurred...... intermittently and lasted 215–227 ms. The weak feeding current and fast response of the copepods allowed ample time for detection of cells entrained in the feeding current and no distant olfaction was observed. Modeled effect of cell size on cell surface concentration of cue chemicals show that only cells...

  17. Toxicity of trace metals to Acartia tonsa in the Elizabeth River and southern Chesapeake Bay

    Science.gov (United States)

    Sunda, W. G.; Tester, P. A.; Huntsman, S. A.

    1990-03-01

    Dissolved zinc and copper and free cupric ions were present at high concentrations in water from the Elizabeth River estuary (a polluted tributary of the southern Chesapeake Bay) when compared to values in nearby Hampton Roads and lower Chesapeake Bay. Zinc concentrations at three stations in the Elizabeth River ranged from 87 to 1550 nM compared to values of 3·1 to 16 nM at four stations in the southern Chesapeake Bay. Likewise, free cupric ion concentration ranged from 10 -11·6 to 10 -10·1 M at the Elizabeth River stations, but was appreciably lower (10 -12·3 to 10 -12·6 M) in samples from Hampton Roads and the lower bay. In bioassays conducted with the copepod Acartia tonsa, the survival of naupliar larvae was much lower in Elizabeth River samples, containing high levels of copper and zinc, than in samples from the Chesapeake Bay or Newport River estuary which contained much lower levels of these metals. Based on previous results in trace metal ion buffered media, measured free cupric ion concentrations and estimated free zinc ion concentrations appear to have been high enough in the Elizabeth River samples to account for at least some of the observed decrease in larval survival. Furthermore, the addition of chelators, EDTA and NTA, that complex and detoxify copper and zinc (as well as cadmium, nickel and lead) significantly increased larval survival in the Elizabeth River samples. These results strongly support the hypothesis that elevated levels of copper and zinc (and possibly other toxic trace metals) occur at sufficiently high concentrations in Elizabeth River water to adversely affect Acartia tonsa and other sensitive estuarine organisms.

  18. Population dynamics of a dominant species (Pseudocalanus, Acartia and Temora) in the Gulf of Gdansk (southern Baltic Sea)

    Science.gov (United States)

    Dzierzbicka-Glowacka, L.; Janecki, M.; Lemieszek, A.; Jakacki, J.; Nowicki, A.

    2012-04-01

    Copepods are the most important secondary producers of the world ocean. They represent an important link between phytoplankton, microzooplankton and higher trophic levels such as fish. With regard to their role in marine food webs, it is important to know how environmental variations affect their population. The population dynamics of a dominant species (Pseudocalanus, Acartia and Temora) in the southern Baltic Sea have been investigated within the grant which is supported by the Polish State Committee of Scientific Research. We intend to study the impact of climate changes on the development of the investigated copepods in the southern Baltic Sea through the impact of food concentration, temperature and salinity within the next few decades. Therefore, the goal within grant-Poland is developing the marine ecosystem model for Baltic Sea 3D CEMBSv2 (a coupled biological-hydrodynamic model) with a new 3D copepod model. 3D CEMBSv2 is a fully coupled model adopted for the Baltic Sea. The model is based on CESM1.0 (Community Earth System Model), in our configuration it consists of two active components (ocean and ice) driven by central coupler (CPL7). Ocean (POP version 2.1) and ice models (CICE model, version 4.0) are forced by atmospheric and land data models. Atmospheric data sets are provided by ICM-UM model from University of Warsaw. Additionally land model provides runoff of the Baltic Sea (currently 78 rivers). Ecosystem model is based on an intermediate complexity marine ecosystem model for the global domain and consists of 11 main components: zooplankton, small phytoplankton, diatoms, cyanobacteria, two detrital classes, dissolved oxygen and the nutrients nitrate, ammonium, phosphate and silicate. The copepod model consists of ten state variables with masses and numbers for each of five model stage, grouping stages to: the non feeding stages and eggs are represented by the stage - eggs-N2, following are the naupliar stages - N3-N6, then two copepodite stages - C

  19. A new species of Acartia (Copepoda, Calanoida) from Cochin Harbour, India, and adjacent areas

    Digital Repository Service at National Institute of Oceanography (India)

    Abraham, S.

    During the course of a study of the family Acartiidae of Cochin harbour and its neighbourhood, a species of Acartia different from all other known species of Acartia, was found. Its characteristics, habitat and seasonal distribution form the theme...

  20. Mandible characteristics and allometric relations in copepods: a reliable method to estimate prey size and composition from mandible occurrence in predator guts Caracterización de mandíbulas y relación alométrica en copépodos: método adecuado para estimar tamaño y composición de presas usando mandíbulas encontradas en intestinos de depredadores

    Directory of Open Access Journals (Sweden)

    Ricardo Giesecke

    2004-12-01

    Full Text Available The size and shape of the cutting edge of the mandibles from the five most abundant copepod species found in Mejillones Bay are described with the aim to create a helpful tool for the identification of copepod prey and their size from predator gut contents. Good allometric relationships were found between the carapace length and the mandible width for the species Paracalanus parvus, Centropages brachiatus and Acartia tonsa. By contrast, the cyclopoids Oithona sp. and Corycaeus sp. did not present a good relationship between these two parameters, presumably due to the presence of more than a species in the study area. Applying the edge index (Itoh 1970 the copepods were classified as herbivores (e.g., P. parvus, omnivores (e.g., C. brachiatus and A. tonsa, and carnivores (e.g., Oithona sp.. In general, there was a tight relationship between the morphometric characters of the mandible blade and the trophic ecology of each species. The good relationship between the mandible width and the carapace length of the calanoid species will permit the estimation of the size of an ingested copepod by a predator, within a certain degree of accuracy, by measuring the width of the mandibles found in gut contents. This relationship and the supplementary characterization of the mandible blade will help improve the knowledge of the feeding ecology of the mesozooplankton in northern ChileEl tamaño y forma del extremo cortante de la mandíbula de las cinco especies de copépodos más abundantes en la bahía de Mejillones fueron descritas con el propósito de crear una herramienta útil para la identificación de contenidos intestinales de depredadores de copépodos. Aparte de esto, se analizó la relación alométrica entre la longitud cefalotoráxica y el diámetro mandibular para las especies Paracalanus parvus, Centropages brachiatus Acartia tonsa, Oithona sp. y Corycaeus sp. A diferencia de las especies calanoídeas, las especies ciclopoídeas no presentaron

  1. Ocean Acidification Impact to Copepod Populations Mediated by Changes in Prey Quality

    Science.gov (United States)

    Schoo, K. L.; McLaskey, A.; Love, B. A.; Keister, J. E.; Olson, M. B.

    2016-02-01

    Research shows that elevated atmospheric pCO2 and subsequent ocean acidification (OA) have physiological consequences for individual organisms. However, existing research does not adequately address how OA effects to individuals are coupled across trophic levels. Pelagic copepods form an important link between primary production and higher trophic levels, making it crucial to understand how these organisms are affected by OA directly and through changes in their phytoplankton prey. Recent studies indicate that OA affects phytoplankton by altering their physiology and biochemistry, often increasing growth rate and fatty acid content. As copepod grazing and fecundity can vary with these prey characteristics, OA mediated changes in phytoplankton quality may be an important indirect mechanism through which OA acts on copepod populations and, ultimately, marine food webs. We carried out experiments investigating the direct and indirect effects of OA on copepod (Acartia hudsonica) production at two different temperatures, 12°C and 17°C. Phytoplankton (Rhodomonas salina) were grown under three different pCO2 conditions (400, 800 and 1200 ppm) for five generations and fed to adult female copepods maintained under the same three pCO2 levels. Phytoplankton physiology and biochemistry were analysed, focussing on the fatty acid composition. We found significant increases in phytoplankton lipids with increasing pCO2 levels, allowing us to test our hypothesis that OA effects on copepods may be mediated by food quality. Following an acclimation period copepod grazing, respiration, fatty acid composition, egg production, hatching rate and the ontogenetic development of nauplii were analysed. The same experiments were performed with the copepod Calanus pacificus feeding on a diatom (Dytilum brightwelii) and a dinoflagellate (Prorocentrum micans) using the same experimental design at 12°C.

  2. Automated identification of copepods using digital image processing and artificial neural network.

    Science.gov (United States)

    Leow, Lee Kien; Chew, Li-Lee; Chong, Ving Ching; Dhillon, Sarinder Kaur

    2015-01-01

    Copepods are planktonic organisms that play a major role in the marine food chain. Studying the community structure and abundance of copepods in relation to the environment is essential to evaluate their contribution to mangrove trophodynamics and coastal fisheries. The routine identification of copepods can be very technical, requiring taxonomic expertise, experience and much effort which can be very time-consuming. Hence, there is an urgent need to introduce novel methods and approaches to automate identification and classification of copepod specimens. This study aims to apply digital image processing and machine learning methods to build an automated identification and classification technique. We developed an automated technique to extract morphological features of copepods' specimen from captured images using digital image processing techniques. An Artificial Neural Network (ANN) was used to classify the copepod specimens from species Acartia spinicauda, Bestiolina similis, Oithona aruensis, Oithona dissimilis, Oithona simplex, Parvocalanus crassirostris, Tortanus barbatus and Tortanus forcipatus based on the extracted features. 60% of the dataset was used for a two-layer feed-forward network training and the remaining 40% was used as testing dataset for system evaluation. Our approach demonstrated an overall classification accuracy of 93.13% (100% for A. spinicauda, B. similis and O. aruensis, 95% for T. barbatus, 90% for O. dissimilis and P. crassirostris, 85% for O. similis and T. forcipatus). The methods presented in this study enable fast classification of copepods to the species level. Future studies should include more classes in the model, improving the selection of features, and reducing the time to capture the copepod images.

  3. 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

    , Temora longicornis and Acartia tonsa, as well as in their faecal pellets. The fate of the phytoplankton pigments was studied in A. tonsa fed a diatom and a cryptophyte at a low and a high prey concentration. The concentration of gut pigments generally declined rapidly within the first 5–10 min after...... feeding terminated. The decline in pigment concentration was faster in copepods fed high concentrations of phytoplankton and specially when fed the diatom. However, after 3h of no feeding only minor changes in gut pigment composition were found mainly in alloxanthin, chlorophyll a and diadinoxanthin...

  4. Prey detection and prey capture in copepod nauplii

    DEFF Research Database (Denmark)

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

    2012-01-01

    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...... 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...

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

    DEFF Research Database (Denmark)

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

    2012-01-01

    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...

  6. 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.

    have influenced the decrease in the abundance of typical epipelagic organisms toward deeper waters. The mean zooplankton crop in the upper 1000 m was 2.1 g dry wt m- 2 (SO = 0.35). While day and night differences in the column values were negligible...., Zahuranec,B.J. and Johnson,R.K. (cds), Pelagic Biogeography. UNESCO Technical Papers in Marine Science, Vol. 49, pp. 3-8. !\

  7. Turbulence triggers vigorous swimming but hinders motion strategy in planktonic copepods

    Science.gov (United States)

    Michalec, François-Gaël; Souissi, Sami; Holzner, Markus

    2015-01-01

    Calanoid copepods represent a major component of the plankton community. These small animals reside in constantly flowing environments. Given the fundamental role of behaviour in their ecology, it is especially relevant to know how copepods perform in turbulent flows. By means of three-dimensional particle tracking velocimetry, we reconstructed the trajectories of hundreds of adult Eurytemora affinis swimming freely under realistic intensities of homogeneous turbulence. We demonstrate that swimming contributes substantially to the dynamics of copepods even when turbulence is significant. We show that the contribution of behaviour to the overall dynamics gradually reduces with turbulence intensity but regains significance at moderate intensity, allowing copepods to maintain a certain velocity relative to the flow. These results suggest that E. affinis has evolved an adaptive behavioural mechanism to retain swimming efficiency in turbulent flows. They suggest the ability of some copepods to respond to the hydrodynamic features of the surrounding flow. Such ability may improve survival and mating performance in complex and dynamic environments. However, moderate levels of turbulence cancelled gender-specific differences in the degree of space occupation and innate movement strategies. Our results suggest that the broadly accepted mate-searching strategies based on trajectory complexity and movement patterns are inefficient in energetic environments. PMID:25904528

  8. Glutathione transferase activity and oocyte development in copepods exposed to toxic phytoplankton

    DEFF Research Database (Denmark)

    Kozlowsky-Suzuki, Betina; Koski, Marja; Hallberg, Eric

    2009-01-01

    Organisms present a series of cellular mechanisms to avoid the effects of toxic compounds. Such mechanisms include the increase in activity of detoxification enzymes [e.g., 7-ethoxyresorufin-O-deethylase (EROD) and glutathione S-transferase (GST)I, which could explain the low retention of ingested...... toxins generally observed in copepods. In addition, decreasing gross growth efficiency (GGE) of copepods with increasing concentration of toxic diets could be caused either by a high expenditure coping with toxins (e.g., increase in the activity of detoxification enzymes) or by a deterioration...... of reproductive tissues. To assess the effect of toxic phytoplankton on the activity of detoxification enzymes and on oocyte maturation of Acartia tonsa and Temora longicornis, feeding and egg production experiments were carried out with a variety of toxic diets and an adequate non-toxic food control (Rhodomonas...

  9. Microplastic potentiates triclosan toxicity to the marine copepod Acartia tonsa (Dana)

    DEFF Research Database (Denmark)

    Syberg, Kristian; Nielsen, Anne; Khan, Farhan

    2017-01-01

    Microplastics (MP) are contaminants of environmental concern partly due to plastics ability to sorb and transport hydrophobic organic contaminants (HOC). The importance of this "vector effect" is currently being debated in the scientific community. This debate largely ignores that the co-exposure......Microplastics (MP) are contaminants of environmental concern partly due to plastics ability to sorb and transport hydrophobic organic contaminants (HOC). The importance of this "vector effect" is currently being debated in the scientific community. This debate largely ignores that the co...

  10. Predatory and suspension feeding of the copepod Acartia tonsa in turbulent environments

    DEFF Research Database (Denmark)

    Saiz, E.; Kiørboe, Thomas

    1995-01-01

    in a depression of clearance rates, although the rates were still significantly higher than those observed in calm water. The depression of clearance rates at high turbulence intensities was due partly to a decline in capture success, but mainly to a decrease in reactive distance, because turbulence interferes...

  11. Redescription of the poorly known planktonic copepod Pontellopsis lubbockii (Giesbrecht, 1889) (Pontellidae) from the Eastern Tropical Pacific with a key to species

    OpenAIRE

    Eduardo Suarez-Morales; Eva Kozak

    2012-01-01

    Abstract During a survey of the epipelagic zooplankton carried out off the coast of the Mexican states of Jalisco and Colima, in the Eastern Tropical Pacific, female and male specimens of the poorly known calanoid copepod Pontellopsis lubbockii (Giesbrecht, 1889) were collected. Because previous descriptions and illustrations are largely incomplete and have caused some taxonomical confusion, this species is fully redescribed from specimens from the Mexican Pacific. The species has some charac...

  12. Morphometric differences in two calanoid sibling species, Boeckella gracilipes and B. titicacae (Crustacea, Copepoda

    Directory of Open Access Journals (Sweden)

    Patricio De los Ríos Escalante

    2012-12-01

    Full Text Available Calanoid copepods are abundant in South American inland waters and include widespread species, such as Boeckella gracilipes (Daday, 1902, which occurs from the Ecuador to Tierra del Fuego Island. This species occurs under various environmental conditions, and is found in oligotrophic lakes in Patagonia (39-54°S and in shallow mountain lakes north of 39°S. The aim of the present study is to conduct a morphometric comparison of male specimens of B. titicacae collected in Titicaca and B. gracilipes collected in Riñihue lakes, with a third population of B. gracilipes collected in shallow ponds in Salar de Surire. Titicaca and Riñihue lakes are stable environments, whereas Salar de Surire is an extreme environment. These ponds present an extreme environment due to high exposure to solar radiation and high salinity levels. The results of the study revealed differences among the three populations. These results agree well with systematic descriptions in the literature on differences between the populations of Titicaca and Riñihue lakes, and population of Salar de Surire differs slightly from the other two populations. It is probable that the differences between the population of Salar de Surire and the other two populations result from the extreme environment in Salar de Surire. High exposure to solar radiation, high salinity and extreme variations in temperature enhance genetic variations that are consequently expressed in morphology.

  13. Life histories and seasonal dynamics of common boreal pelagic copepods (Crustacea, Copepoda inhabiting an oligotrophic Fennoscandian lake

    Directory of Open Access Journals (Sweden)

    Svein Birger WÆRVÅGEN

    2010-08-01

    Full Text Available The annual seasonal abundance and spatial distribution of four widespread pelagic copepods, the Palaeartic calanoid Eudiaptomus gracilis, the cyclopoids Mesocyclops leuckarti and Thermocyclops oithonoides, and the Holartic Cyclops scutifer were investigated in Lake Gjerstadvann, an oligotrophic boreal lake. Important ecological traits such as life cycles, pelagic microhabitats and wintering strategies varied strongly between the investigated copepods, and influenced seasonal succession in the plankton community. Fish predation did not seem to affect copepod abundances, except perhaps the two lage-sized, less abundant species, the Palaeartic calanoid Heterocope saliens and the Holartic cyclopoid Cyclops abyssorum. Life cycles varied from one (C. scutifer to three (M. leuckarti and E. gracilis complete generations per year, primarily related to habitat temperatures. Wintering took place as late instars (C. scutifer, C. abyssorum or cop V and adults (E. gracilis in the plankton, late instars in profundal (T. oithonoides or littoral (M. leuckarti sediment diapause, and embryonic diapause in sediment egg bank (H. saliens. C. scutifer and C. abyssorum exhibited delayed development in the profundal waters during winter, which could be characterised as so-called "active diapause". C. scutifer, T. oithonoides, and C. abyssorum in Lake Gjerstadvann were probably negatively affected by acidified waters. M. leuckarti seemed to be the most acid-tolerant of these species being able to endure pH slightly below 5.0, whereas T. oithonoides was usually absent at such pH levels. The calanoid species H. saliens and E. gracilis were extremely tolerant towards acidic environments. The yearly differences in population abundance as indicated by the fluctuations in the diapausing populations were probably due to environmental variations in water chemistry occurring during the most vulnerable ontogenetic stages, i.e., eggs and nauplii. Even if the pelagic ecosystem in

  14. 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.

  15. Evaluation of metagenetic community analysis of planktonic copepods using Illumina MiSeq: Comparisons with morphological classification and metagenetic analysis using Roche 454.

    Science.gov (United States)

    Hirai, Junya; Nagai, Satoshi; Hidaka, Kiyotaka

    2017-01-01

    Metagenetics is a rapid and taxonomically comprehensive method for revealing community structures within environmental samples, based on large amounts of sequence data produced by high-throughput sequencers. Because community structures of planktonic copepods are important in the ocean owing to their high diversity and abundance, a metagenetic analysis of the 28S D2 region using Roche 454 was previously developed. However, the Illumina MiSeq platform with a high sequence output is being used more frequently in metagenetics, and non-calanoid copepods have not previously been fully evaluated. Here, we evaluated an Illumina MiSeq-based metagenetic analysis using a mock community and field-collected samples that were examined in a previous study using Roche 454, and the community structure, including non-calanoid copepods, was compared among morphological and metagenetic analyses. We removed a singleton read and applied an appropriate abundance threshold to remove erroneous Molecular Operational Taxonomic Units (MOTUs) with low-abundance sequences in the MiSeq-based analysis. Results showed that the copepod community was successfully characterized using Illumina MiSeq. Higher-quality sequences were obtained using MiSeq than by Roche 454, which reduced the overestimation of diversity, especially at a strict 99% similarity threshold for MOTU clustering. Taxonomic compositions in terms of both biomass and presence/absence of species, including non-calanoids, were more appropriately represented in the MiSeq- than in Roche 454-based analysis. Our data showed that metagenetic analysis using Illumina MiSeq is more useful for revealing copepod communities than Roche 454, owing to the lower cost and higher quality.

  16. Copepod Response Behavior in Turbulence

    Science.gov (United States)

    Krizan, Daniel

    The objective of this thesis is to determine copepod response to turbulence generated by obstacles in cross flow. Mainly, flow and copepod response downstream a square fractal grid is examined but experiments downstream a cylinder provides comparison. This is done by simultaneously measuring the copepods position and velocity using 3D-PTV in a measurement volume and measuring the two dimensional three component velocity vectors of the flow using stereo PIV. These measurements are done in a way that does not elicit copepod response. Tomographic PIV is done downstream the square fractal grid without copepods to gain volumetric velocity knowledge of the flow in the measurement volume. Copepods are known to execute sudden high speed jumps (or escapes) in response to sensed hydrodynamic signals. The fractal grid was shown to elicit copepod escape, specifically directly downstream with escape frequency decreasing further downstream where turbulence levels were much lower. It was found that at a slower freestream speed copepods exhibited jumps not in reaction to flow disturbances but to reorient themselves (cruise swimming). There was almost no copepod response in the wake of a cylinder, but copepods again exhibited cruise swimming behavior at a slower freestream speed. In regions with high maximum principal strain rate (MPSR) downstream of the fractal grid, copepods were observed to exhibit multiple escapes. Moreover, copepods were observed to jump towards regions of lower turbulence and against the freestream direction. From stereo PIV, instantaneous 2D MPSR values of less than 3s -1 were shown to create escape in 60% of copepod escapes analyzed. Finally, it was found that on average larger MPSR resulted in larger jumps from copepods.

  17. Swim and fly: escape strategy in neustonic and planktonic copepods

    DEFF Research Database (Denmark)

    Svetlichny, Leonid; Larsen, Poul Scheel; Kiørboe, Thomas

    2018-01-01

    . helgolandicus (106 cm s-1). The average specific power produced by the two pontellids during out-of-water jumps (1700-3300 W kg-1 muscle mass) was close to that during submerged jumps (900-1600 W kg-1 muscle mass) and, in turn, similar to that produced during submerged jumps of C. helgolandicus (1300 W kg-1...... muscle mass). The pontellids may shake off water adhering to their body by repeated strokes of the limbs during flight, which leads to a slight acceleration in the air. Our observations suggest that out-of-water jumps of pontellids are not dependent on any exceptional ability to perform this behavior......, and one pelagic calanoid copepod, Calanus helgolandicus (euxinus). We show that jumping out of the water does not happen just by inertia gained during the copepod's acceleration underwater, but also requires the force generated by the thoracic limbs when breaking through the water's surface to overcome...

  18. Morphometric differences in two calanoid sibling species, Boeckella gracilipes and B. titicacae (Crustacea, Copepoda) Diferencias morfométricas en dos especies hermanas Boeckella gracilipes y Boeckella titicacae (Crustacea, Copepoda)

    OpenAIRE

    Patricio de los Ríos Escalante

    2012-01-01

    Calanoid copepods are abundant in South American inland waters and include widespread species, such as Boeckella gracilipes (Daday, 1902), which occurs from the Ecuador to Tierra del Fuego Island. This species occurs under various environmental conditions, and is found in oligotrophic lakes in Patagonia (39-54°S) and in shallow mountain lakes north of 39°S. The aim of the present study is to conduct a morphometric comparison of male specimens of B. titicacae collected in Titicaca and B. graci...

  19. Fight and flight in dinoflagellates?

    DEFF Research Database (Denmark)

    Selander, Erik; Fagerberg, Tony; Wohlrab, Sylke

    2012-01-01

    We monitored the kinetics of grazer-induced responses in the marine dinoflagellate Alexandrium tamarense. Chemical cues from each of three calanoid copepods (Calanus sp., Centropages typicus, and Acartia tonsa) induced increased toxicity and suppressed chain formation in A. tamarense. Both chemic...

  20. Copepods in turbid shallow soda lakes accumulate unexpected high levels of carotenoids.

    Directory of Open Access Journals (Sweden)

    Tobias Schneider

    Full Text Available Carotenoids are protective pigments present in many aquatic organisms that reduce the photooxidative stress induced by short-wavelenght solar radiation, yet increase their susceptibility to predators. Arctodiaptomus spinosus, a calanoid copepod typically found in many fishless shallow soda lakes, shows large between-lake differences in pigmentation. Here, we attribute these differences to the environmental state of these ecosystems, namely, 'dark water' lakes with submersed vegetation and turbid 'white' lakes lacking macrophytes. Copepod carotenoid concentration in the turbid 'white' lakes was significantly (about 20-fold higher than in the 'dark water' ones, although the latter systems were characterized by higher transparency. In addition, males had on a dry weight basis around three times higher carotenoid concentrations than females. Mycosporine-like amino acids (direct UV screening substances were found in all cases, but in low concentration. The environmental conditions in these ecosystems were largely shaped by the presence/absence of submersed macrophytes Thus, in the turbid lakes, the strong wind-driven mixis allows for copepods to be brought to the surface and being exposed to solar radiation, whereas in 'dark water' ones, macrophytes reduce water turbulence and additionally provide shelter. Our results explain the counter-intuitive notion of strong red pigmentation in copepods from a turbid ecosystem and suggest that factors other than high UV transparency favor carotenoid accumulation in zooplankton.

  1. 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

  2. Copepod distribution and production in a Mid-Atlantic Ridge archipelago

    Directory of Open Access Journals (Sweden)

    PEDRO A.M.C. MELO

    2014-12-01

    Full Text Available The Saint Peter and Saint Paul Archipelago (SPSPA are located close to the Equator in the Atlantic Ocean. The aim of this study was to assess the spatial variations in the copepod community abundance, and the biomass and production patterns of the three most abundant calanoid species in the SPSPA. Plankton samples were collected with a 300 µm mesh size net along four transects (north, east, south and west of the SPSPA, with four stations plotted in each transect. All transects exhibited a tendency toward a decrease in copepod density with increasing distance from the SPSPA, statistically proved in the North. Density varied from 3.33 to 182.18 ind.m−3, and differences were also found between the first perimeter (first circular distance band and the others. The total biomass varied from 15.25 to 524.50 10−3 mg C m−3 and production from 1.19 to 22.04 10−3 mg C m−3d−1. The biomass and production of Undinula vulgaris (Dana, 1849, Acrocalanus longicornis Giesbrecht, 1888 and Calocalanus pavo (Dana, 1849 showed differences between some transects. A trend of declining biodiversity and production with increasing distance from archipelago was observed, suggesting that even small features like the SPSPA can affect the copepod community in tropical oligotrophic oceanic areas.

  3. Does predation control adult sex ratios and longevities in marine pelagic copepods?

    DEFF Research Database (Denmark)

    Hirst, A.G.; Bonnet, D.; Conway, D.V.P.

    2010-01-01

    We assess the causes of adult sex ratio skew in marine pelagic copepods by examining changes in these ratios between the juveniles and adults, sexual differences in juvenile stage durations, and mortality rates of adults in the field and laboratory (when free from predators). In the field, late...... copepodite stages (CIV and CV) commonly have sex ratios that are either not significantly different from equity (1 : 1), or slightly male biased. By contrast, in adults, these ratios are commonly significantly biased toward female dominance. Sex ratio skews are therefore primarily attributable to processes...... in adults. Members of the non-Diaptomoidea have especially skewed adult ratios; in the members Oithonidae and Clausocalanidae this is not generated from differences between male and female adult physiological longevity (i.e., laboratory longevity when free of predators). In the genera Acartia, Oithona...

  4. Lethal and Sublethal Toxicity Comparison of BFRs to Three Marine Planktonic Copepods: Effects on Survival, Metabolism and Ingestion.

    Directory of Open Access Journals (Sweden)

    Wenjing Gong

    Full Text Available The estuarine planktonic copepods have a wide geographical distribution and commendable tolerance to various kinds of contaminants. The primary aim of the present study was to contrast the impacts of model POPs (TBBPA and HBCD on three common estuarine planktonic copepods (Oithona similis, Acartia pacifica and Pseudodiaptomus inopinus and establish a protocol for the assessment of acute toxicity of marine organic pollutants. We first quantified the 96h-LC50 (0.566, 0.04 and 0.257 mg/L of TBBPA to the three subjects above respectively and 0.314 mg/L of HBCD to P. inopinus; all reported concentrations are nominal values. In the sub-lethal toxicity tests, it was turned out that the effects of copepods exposed to TBBPA could product different influences on the energy ingestion and metabolism. Different type of pollutions, meanwhile, could also bring varying degree effect on the target copepods. In general, the indicators (the rate of oxygen consumption, ammonia excretion, food ingestion and filtration in higher concentration groups showed marked significant difference compared with controls as well a dose-effect relationship. The study also extended the research on the joint toxicity of TBBPA and HBCD based on the survival rate of P.inopinus. Whether 1:1 concentration or 1:1 toxic level, the research showed synergy effect relative to single exposure conditions. The result indicated that current single ecological testing used for environmental protection activities may underestimate the risk for copepods. It was also demonstrated that short-term sub-lethal experiment could be a standard to evaluate the sensitivity of copepods to POPs.

  5. Life strategies, energetics and growth characteristics of Calanoides ...

    African Journals Online (AJOL)

    40–50% dry mass) and extremely low metabolism in the SAC/ABF, suggesting diapause. This study provides the first data on lipid composition (lipid classes, fatty acids and alcohols) of this copepod in the region; in particular, the diapausing C5s contained high levels of long-chain, mono-unsaturated fatty acids (23% of all ...

  6. Role of small-sized copepods in the lipid-driven Arctic marine food web

    Science.gov (United States)

    Daase, M.; Boissonnot, L.; Graeve, M.; Søreide, J.; Niehoff, B.

    2016-02-01

    Despite of the low individual biomass of small-sized copepods such as the calanoid Pseudocalanus minutus and the cyclopoid Oithona similis, they are extremely numerous which make them an important trophic component in Arctic marine ecosystems. Due to the strong seasonality in light and thus primary production and food availability, the accumulation of lipid reserves is a key feature in Arctic marine ecosystems. However, very few studies exist on the lipid biochemistry of small copepods such as P. minutus and O. similis. In order to investigate the importance of these species in terms of transfer of lipids from primary production to higher trophic levels, feeding experiments were conducted, based on animals from Billefjorden, a high-Arctic fjord in Svalbard, Norway. A mixture of 13C labeled flagellates and diatoms was fed to the animals and the transfer and assimilation of lipid carbon, fatty acids and fatty alcohols was analyzed with gas chromatography-IRMS technique (CSIA). The results revealed that both species were incorporating dietary lipids in high quantities. The highest accumulation occurred in P. minutus in which 54.4% of the lipids were exchanged after 21 days, whereas 9.4% were assimilated in O. similis. Hence, at least this amount of carbon was used for metabolism and replaced by feeding. The lipid composition of the copepods did not reflect exactly the algal lipids, and differed between P. minutus and O. similis. Our results suggested intrinsic preferences in the accumulation of particular fatty acids, probably related to species-specific body requirements. This emphasizes the importance of also food quality in Arctic marine systems. Due to the relatively high lipid turnover rates in particularly in P. minutus, also small copepods are important drivers of the lipid-driven Arctic marine food web.

  7. Copepods of the nearshore waters of Bombay

    Digital Repository Service at National Institute of Oceanography (India)

    Gajbhiye, S.N.; Stephen, R.; Nair, V.R.; Desai, B.N.

    Variability in copepod population was studied along 2 transects off Mahim and Versova (Bombay, Maharashtra, India) during November 1979 to December 1980 covering eight stations from the creek towards the offshore area. Contribution of copepods...

  8. 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...

  9. 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.

    for his valuable advice. We acknowledge the help from Shweta, Genevieve and Byju for data collection and analysis. EIOPS was funded by the Ministry of Earth Science (MoES), New Delhi. This is NIO contribution No.xxxx. References Achuthankutty, C.T., N...

  10. Effects of methyltestosterone, letrozole, triphenyltin and fenarimol on histology of reproductive organs of the copepod Acartia tonsa

    DEFF Research Database (Denmark)

    Watermann, Burkard T.; Albanis, Triantafyllos A.; Dagnac, Thierry

    2013-01-01

    an inhibition of oogenesis, oocyte maturation and yolk formation, respectively, which was most pronounced at the lowest concentrations tested. In LET exposed males, spermatogenesis was enhanced with very prominent gamete stages; in some stages apoptosis occurred. The spermatophore was hypertrophied...... and displayed deformations. In females, LET induced a disorder of oogenesis and disturbances in yolk synthesis. TPT stimulated the male reproductive system at 0.0014 and 0.0035μg TPT-SnL−1, whereas inhibiting effects were observed in the female gonad at 0.0088μg TPT-SnL−1. In FEN exposed females proliferation...

  11. Improving cold storage of subitaneous eggs of the copepod Acartia tonsa Dana from the Gulf of Mexico (Florida, USA)

    DEFF Research Database (Denmark)

    Drillet, Guillaume; Lindley, L.C.; Michels, A.

    2007-01-01

    . We consider that the use of antibiotics at the right dosage to be a means to increase the storage capacity of the Gulf of Mexico strain of A. tonsa eggs, which do not show any capacity to be stored for long periods of time, compared with some other strains. In addition eggs that were between 5 and 7...

  12. Towards an internationally harmonized test method for reproductive and developmental effects of endocrine disrupters in marine copepods

    DEFF Research Database (Denmark)

    Kusk, Kresten Ole; Wollenberger, Leah

    2007-01-01

    with marine copepods (Acartia tonsa, Nitocra spinipes, Tisbe battagliai, and Amphiascus tenuiremis). The present paper gives an overview on the endocrine system of crustaceans with special emphasis on development and reproduction, which are targets for endocrine disruption, and reviews available methods......New and updated methods to detect and characterize endocrine disrupting chemicals (EDCs) are urgently needed for the purpose of environmental risk assessment since these substances are often not detected using existing chronic toxicity tests. Numerous reports on the effects of EDCs on crustacean...... development and reproduction have been published and the development of life-cycle tests with crustaceans has been prioritized within the OECD work program for endocrine disrupter testing and assessment. As a result, Sweden, and Denmark initiated a proposal for development of a full life-cycle test...

  13. Composition of the zooplankton community,with emphasis in copepods, in Punta Morales,Golfo de Nicoya,Costa Rica

    Directory of Open Access Journals (Sweden)

    Ernesto Brugnoli-Olivera

    2004-12-01

    Full Text Available 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 µm 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.Rev.Biol.Trop.52(4:897-902.Epub 2005 Jun 24.Se estudió la composición de la comunidad mezoplanctónica en Punta Morales,Golfo de Nicoya, Pacífico de Costa Rica,en 1997,arrastrando oblicuamente una red de plancton (280 µm,con flujómetrodurante marea alta y baja.La comunidad estuvo caracterizada por la presencia de organismos holo y meroplanctónicos.Los principales grupos holoplanctónicos fueron copépodos (80%y quetognatos (16%.Las especies más abundantes fueron los copépodos Acartia lilljeborgii y Paracalanus parvus;A. lilljeborgii es una especie estuarina típica que mantiene altas poblaciones en sistemas estuarinos.El meroplancton estuvo representado principalmente por larvas de crustáceos (66%,e ictioplancton (18%.La dominancia de larvas de crustáceos e ictioplancton evidencian la importancia ecológica de la zona de Punta Morales.

  14. 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...

  15. 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...... easily be parameterized for other planktonic organisms, and be used to plan experiments about sexual selection......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...

  16. 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

  17. comment="please make the changes marked up in the attached pdf"Sex-Dependent Effects of Caloric Restriction on the Ageing of an Ambush Feeding Copepod.

    Science.gov (United States)

    Saiz, Enric; Calbet, Albert; Griffell, Kaiene

    2017-10-04

    Planktonic copepods are a very successful group in marine pelagic environments, with a key role in biogeochemical cycles. Among them, the genus Oithona is one of the more abundant and ubiquitous. We report here on the effects of caloric (food) restriction on the ageing patterns of the copepod Oithona davisae. The response of O. davisae to caloric restriction was sex dependent: under food limitation, females have lower age-specific mortality rates and longer lifespans and reproductive periods; male mortality rates and life expectancy were not affected. Males are more active swimmers than females, and given their higher energetic demands presumably generate reactive oxygen species at higher rates. That was confirmed by starvation experiments, which showed that O. davisae males burn through body reserves much faster, resulting in shorter life expectancy. Compared with common, coastal calanoid copepods, the effects of caloric restriction on O. davisae appeared less prominent. We think this difference in the magnitude of the responses is a consequence of the distinct life-history traits associated with the genus Oithona (ambush feeder, egg-carrier), with much lower overall levels of metabolism and reproductive effort.

  18. Effect of diatom morphology on the small-scale behavior of the copepod Temora stylifera (Dana, 1849)

    KAUST Repository

    Mahadik, Gauri A.

    2017-05-12

    We explored the small-scale behavior of the calanoid copepod Temora stylifera in relation to the diatoms Chaetoceros socialis, Leptocylindrus aporus, Leptocylindrus danicus and Pseudo-nitzschia calliantha offered as monospecific diets at similar carbon concentrations. These four diatoms are characterized by distinct size, shape and colony forming ability and are important components of the autumnal bloom co-occurring with the seasonal peak of T. stylifera abundance in Mediterranean coastal waters. High-speed video recordings showed that T. stylifera acquired cells in a suspension feeding mode while creating feeding currents. Copepod behavior was quantified in terms of feeding, motion, and grooming activities. T. stylifera spent more time in hovering than cruising in presence of all diets. The solitary L. aporus and P. calliantha elicited longer feeding bouts, lower appendage beat frequency and shorter grooming events compared to the colonial L. danicus and C. socialis. Overall the present results indicate that the behavioral responses of T. stylifera to different diatom diets were species-specific. The observed behavioral plasticity may help T. stylifera to adjust rapidly to changes in the food environment and this can be advantageous in exploiting short-lived phytoplankton blooms.

  19. Vertical distribution of planktonic copepods in Tokyo Bay in summer

    National Research Council Canada - National Science Library

    Itoh, Hiroshi; Tachibana, Aiko; Nomura, Hideaki; Tanaka, Yuji; Furota, Toshio; Ishimaru, Takashi

    2011-01-01

    ... in the inner part of Tokyo Bay, central Japan. Acartia sinjiensis showed a peak of the population density in the surface water, which was influenced by river discharge, and Paracalanus parvus s.l...

  20. Effects of ocean acidification on copepods.

    Science.gov (United States)

    Wang, Minghua; Jeong, Chang-Bum; Lee, Young Hwan; Lee, Jae-Seong

    2018-01-05

    Ocean acidification (OA) leads to significant changes in seawater carbon chemistry, broadly affects marine organisms, and considered as a global threat to the fitness of marine ecosystems. Due to the crucial role of copepods in marine food webs of transferring energy from primary producers to higher trophic levels, numerous studies have been conducted to examine the impacts of OA on biological traits of copepods such as growth and reproduction. Under OA stress, the copepods demonstrated species-specific and stage-dependent responses. Notably, different populations of the same copepod species demonstrated different sensitivities to the increased pCO2. In copepods, the deleterious effects of OA are also reinforced by other naturally occurring co-stressors (e.g., thermal stress, food deprivation, and metal pollution). Given that most OA stress studies have focused on the effects of short-term exposure (shorter than a single generation), experiments using adults might have underestimated the damaging effects of OA and the long-term multigenerational exposure to multiple stressors (e.g., increased pCO2 and food shortage) will be required. Particularly, omics-based technologies (e.g., genomics, proteomics, and metabolomics) will be helpful to better understand the underlying processes behind biological responses (e.g., survival, development, and offspring production) at the mechanistic level which will improve our predictions of the responses of copepods to climate change stressors including OA. Copyright © 2018 Elsevier B.V. All rights reserved.

  1. Observing copepods through a genomic lens.

    Science.gov (United States)

    Bron, James E; Frisch, Dagmar; Goetze, Erica; Johnson, Stewart C; Lee, Carol Eunmi; Wyngaard, Grace A

    2011-09-20

    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. 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 provide genomics tools for copepods. Genomics research

  2. 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

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

    DEFF Research Database (Denmark)

    Kulkarni, Devdutt; Gergs, André; Hommen, Udo

    2013-01-01

    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...

  4. 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...... to enhance our understanding of such interactions. These included (1) toxic effects of diatom metabolites on copepods, particularly reproduction, and (2) nutritional effects of diatoms on juvenile to adult copepods. Key issues involved in the impact of diatoms on the dynamics of natural plankton communities...... in situ were also addressed. During the plenary session, the most recent advances on this topic were presented. The plenary session was followed by 3 working groups on (1) production of aldehydes by phytoplankton, (2) toxic and nutritional effects of diatoms on zooplankton, and (3) the chemistry of diatom...

  5. 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.

  6. Dimethyl sulfide triggers search behavior in copepods

    NARCIS (Netherlands)

    Steinke, M.; Stefels, J.; Stamhuis, E.J.

    The oceans are nutritionally dilute, and finding food is a major challenge for many zooplanktonic predators. Chemodetection is necessary for successful prey-capture, but little is known about the infochemicals involved in the interaction between herbivorous copepods and their phytoplankton prey. We

  7. Functional & phylogenetic diversity of copepod communities

    Science.gov (United States)

    Benedetti, F.; Ayata, S. D.; Blanco-Bercial, L.; Cornils, A.; Guilhaumon, F.

    2016-02-01

    The diversity of natural communities is classically estimated through species identification (taxonomic diversity) but can also be estimated from the ecological functions performed by the species (functional diversity), or from the phylogenetic relationships among them (phylogenetic diversity). Estimating functional diversity requires the definition of specific functional traits, i.e., phenotypic characteristics that impact fitness and are relevant to ecosystem functioning. Estimating phylogenetic diversity requires the description of phylogenetic relationships, for instance by using molecular tools. In the present study, we focused on the functional and phylogenetic diversity of copepod surface communities in the Mediterranean Sea. First, we implemented a specific trait database for the most commonly-sampled and abundant copepod species of the Mediterranean Sea. Our database includes 191 species, described by seven traits encompassing diverse ecological functions: minimal and maximal body length, trophic group, feeding type, spawning strategy, diel vertical migration and vertical habitat. Clustering analysis in the functional trait space revealed that Mediterranean copepods can be gathered into groups that have different ecological roles. Second, we reconstructed a phylogenetic tree using the available sequences of 18S rRNA. Our tree included 154 of the analyzed Mediterranean copepod species. We used these two datasets to describe the functional and phylogenetic diversity of copepod surface communities in the Mediterranean Sea. The replacement component (turn-over) and the species richness difference component (nestedness) of the beta diversity indices were identified. Finally, by comparing various and complementary aspects of plankton diversity (taxonomic, functional, and phylogenetic diversity) we were able to gain a better understanding of the relationships among the zooplankton community, biodiversity, ecosystem function, and environmental forcing.

  8. Carotenoid metabolic profiling and transcriptome-genome mining reveal functional equivalence among blue-pigmented copepods and appendicularia

    KAUST Repository

    Mojib, Nazia

    2014-06-01

    The tropical oligotrophic oceanic areas are characterized by high water transparency and annual solar radiation. Under these conditions, a large number of phylogenetically diverse mesozooplankton species living in the surface waters (neuston) are found to be blue pigmented. In the present study, we focused on understanding the metabolic and genetic basis of the observed blue phenotype functional equivalence between the blue-pigmented organisms from the phylum Arthropoda, subclass Copepoda (Acartia fossae) and the phylum Chordata, class Appendicularia (Oikopleura dioica) in the Red Sea. Previous studies have shown that carotenoid–protein complexes are responsible for blue coloration in crustaceans. Therefore, we performed carotenoid metabolic profiling using both targeted and nontargeted (high-resolution mass spectrometry) approaches in four different blue-pigmented genera of copepods and one blue-pigmented species of appendicularia. Astaxanthin was found to be the principal carotenoid in all the species. The pathway analysis showed that all the species can synthesize astaxanthin from β-carotene, ingested from dietary sources, via 3-hydroxyechinenone, canthaxanthin, zeaxanthin, adonirubin or adonixanthin. Further, using de novo assembled transcriptome of blue A. fossae (subclass Copepoda), we identified highly expressed homologous β-carotene hydroxylase enzymes and putative carotenoid-binding proteins responsible for astaxanthin formation and the blue phenotype. In blue O. dioica (class Appendicularia), corresponding putative genes were identified from the reference genome. Collectively, our data provide molecular evidences for the bioconversion and accumulation of blue astaxanthin–protein complexes underpinning the observed ecological functional equivalence and adaptive convergence among neustonic mesozooplankton.

  9. Copepod community structure in Bahia de Banderas during the 2008-2009 La Niña and their transition to the 2009-2010 El Niño

    Directory of Open Access Journals (Sweden)

    Jiménez-Pérez, L.C.

    2016-09-01

    Full Text Available In order to investigate the taxonomic copepod community structure and its relations with the climate conditions in the Pacific Ocean, bimonthly samples were made between February 2009 and April 2010. Samples were collected by vertical tows between the surface and the vicinity of the bottom with a 40 cm mouth diameter and 335 µ mesh size standard zooplankton net. At the beginning of the study water temperatures were low indicating that La Niña conditions prevailed in the bay. However, at the end of June, 2 °C warmer waters associated with El Niño 2009-2010 arrival were detected. These conditions persisted at least until February 2010, and by April water temperature returned to normal. 57 copepods species were recorded, being Acartia tonsa, Acartia lilljeborgi, Oithona plumífera, Centropages furcatus and Nannocalanus minor the most representative species. These five populations accounted most of the 90 % of the collected animals. Cluster and Non-Metric Multidimensional Scaling (NMDS methods show two groups that seem to be associated with La Niña and El Niño conditions. The analysis of similarities (ANOSIM indicated that these assemblages were different (r=0.411; p=0.01 %. Simper analysis indicated that A. tonsa was the dominant population (85.4 % at the end of the 2008-2009 La Niña; this population was followed by A. lilljeborgi (7.9 % and Pareucalanus subtenuis (2.5 %. During the El Niño the dominance of A. tonsa disappeared (32 % while Oithona plumífera, Temora discaudata and Undinula darwinii increased. At the end of El Niño, species diversity and richness also changed. At the end of the 2008-2009 La Niña conditions, 40 species were recorded, while during El Niño the species richness increased to 52 species.

  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

    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...

  11. Distribution of dominant calanoid copepod species in the Greenland Sea during late fall; 06 November 1988 to 12 December 1988 (NODC Accession 0000917)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Between 6 November and 12 December 1988, vertical distributions of Calanus finmarchicus, C. hyperboreus, C. glacialis adn Metridia long were studied at three...

  12. 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

    with resting eggs as part of their life cycles as a result of two different nutrients treatments and a control. We found a tendency to a higher egg production and indeed more eggs in the sediment of nutrient amended tanks. In fact close to 5 million eggs per square meter, making up to 400 million eggs per tank...

  13. Egg production and hatching success in the calanoid copepods Calanus helgolandicus and Calanus finmarchicus in the North Sea from March to September 2001

    DEFF Research Database (Denmark)

    Jonasdottir, Sigrun; Trung, N. H.; Hansen, F.

    2005-01-01

    of seston fatty acids. Seasonal and spatial distribution and production differed between the species. Calanus finmarchicus was found only offshore of the 50-m isobath, with decreasing E-r (37-28 eggs female(-1) day(-1)) from March to July. Calanus helgolandicus had two abundance peaks, in spring and autumn...... to ciliate biomass while only negative relationships were found for all other variables measured. Hatching success in both Calanus species combined was significantly correlated with the essential fatty acid ratio 22:6n3/20:5n3....

  14. Applied and fundamental plankton research would benefit from more joint efforts: examples from Acartia tonsa

    DEFF Research Database (Denmark)

    Hansen, Benni Winding; Jepsen, Per Meyer; Drillet, Guillaume

    2017-01-01

    to dedicated research efforts, industrial production of rotifers, Artemia and, more recently, copepods as live feed for fish hatcheries is established. Yet, there are still many biological and technical challenges to be tackled for optimizing production. Some of these challenges could be eliminated faster...

  15. Ontogenetic optimal temperature and salinity envelops of the copepod Eurytemora affinis in the Seine estuary (France)

    Science.gov (United States)

    Dur, Gaël; Souissi, Sami

    2018-01-01

    Temperature and salinity are important factors shaping the habitats of estuarine ectotherms. Their respective effect varies along the life history moments of species with a complex life cycle. Estuarine species, particularly those living in the salinity gradient, are concerned by habitat changes that can reduce their fitness. Consequently, efforts to define the importance of those two environmental variables on developmental stages are required to enable forecasting estuarine species' future distributions. The present study focuses on the main component of the Seine estuary's zooplankton, i.e. the calanoid copepod Eurytemora affinis, and aims: (i) to establish the role of temperature and salinity in designing the habitat of E. affinis within the Seine estuary; and (ii) to model the habitat of three groups of E. affinis defined through the life cycle as follows: all larval instars (N1-N6), the first to fourth juvenile instars (C1-C4), and the pre-adult and adults instars (C5-Adults). For this purpose, data from intensive field studies of zooplankton sampling during 2002-2010 were used. The fine-scale data, i.e., every 10-20 min, on density and abiotic conditions (salinity, temperature) provided inputs for the computation. We established regions in salinity-temperature space where the three groups of developmental instars exhibit higher densities. The computed habitats differ between developmental groups. In general, the preferendum of salinity increases with ontogeny. The optima of temperature are rather constant between developmental stages (∼14 °C). Our model can be used to determine E. affinis functional habitat (i.e., the spatial relation with structuring factors), to carry out retrospective analysis, and to test future distributions. The present study also emphasizes the need of data from appropriate sampling strategies to conduct habitat definition.

  16. 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...

  17. Testing lagoonal sediments with early life stages of the copepod Acartia tonsa (Dana): An approach to assess sediment toxicity in the Venice Lagoon

    DEFF Research Database (Denmark)

    Picone, Marco; Bergamin, Martina; Delaney, Eugenia

    2018-01-01

    with sea urchin and bivalves embryos. Sediment toxicity data highlighted the high sensitivity and the clear ability of the larval development to discriminate among sediments characterized by different levels of contamination. The data of the definitive study evidenced that inhibition of the larval...

  18. Copepod composition, abundance and diversity in Makupa Creek ...

    African Journals Online (AJOL)

    The taxonomic composition, abundance and spatio-temporal distribution of copepods were analysed from monthly zooplankton samples collected in Makupa creek and Mombasa Harbour (Makupa creek was until recently subjected to considerable dumping of domestic and industrial waste). At least 51 copepod species ...

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

    DEFF Research Database (Denmark)

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

    2014-01-01

    The climate-induced reduction in the mean copepod size, mainly driven by a decrease in the abundance of the large Calanus finmarchicus around 1987, has been linked to the low survival of fish larvae in the North Sea. However, to what extent this sort of reduction in copepod size has any influence...

  20. Prevalence of copepod parasite in Mugil cephalus (Linnaeus, 1758 ...

    African Journals Online (AJOL)

    Many copepod parasites are ecto-parasites which negatively affect the appearance and reduced production of economically important fish species (wild and cultured) which makes their marketing difficult. Copepods have been shown to be the dominant metazoan parasites in Kerala waters. This study therefore examined ...

  1. 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 MR...

  2. 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.

  3. A trait database for marine copepods

    DEFF Research Database (Denmark)

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

    2016-01-01

    , and organised the data into a structured database. We collected 9345 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 on the species level, but some...... phylogenetically conserved traits, such as myelination, were reported on higher taxonomic levels, allowing the entire diversity of around 10 800 recognized marine copepod species to be covered with few records. Besides myelination, data coverage was highest for spawning strategy and body size while information...

  4. A trait database for marine copepods

    DEFF Research Database (Denmark)

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

    2017-01-01

    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...

  5. Noctiluca and copepods grazing on the phytoplankton community in a nutrient-enriched coastal environment along the southwest coast of India.

    Science.gov (United States)

    Arunpandi, N; Jyothibabu, R; Jagadeesan, L; Gireeshkumar, T R; Karnan, C; Naqvi, S W A

    2017-07-01

    The relative grazing impact of Noctiluca scintillans (hereafter referred only Noctiluca) and copepods (Acrocalanus gracilis, Paracalanus parvus, Acartia danae and Oithona similis) on the phytoplankton community in an upwelling-mudbank environment along the southwest coast India is presented here. This study was carried out during the Pre-Southwest Monsoon (April-May) to the Late Southwest Monsoon (August) period in 2014. During the sampling period, large hydrographical transformation was evident in the study area (off Alappuzha, Southwest coast of India); warmer Pre-Southwest Monsoon water column condition got transformed into cooler and nitrate-rich hypoxic waters during the Southwest Monsoon (June-August) due to intense coastal upwelling. Copepods were present in the study area throughout the sampling period with a noticeable increase in their abundance during the Southwest Monsoon. On the other hand, the first appearance of Noctiluca in the sampling location was during the Early Southwest Monsoon (mid-June) and thereafter their abundance increased towards the Peak Southwest Monsoon. The grazing experiments carried out as per the food removal method showed noticeable differences in the feeding preferences of Noctiluca and copepods, especially on the different size fractions of phytoplankton. Noctiluca showed the highest positive electivity for the phytoplankton micro-fraction (av. 0.49 ± 0.04), followed by nano-fraction (av. 0.17 ± 0.04) and a negative electivity for the pico-fraction (av. -0.66 ± 0.06). In total ingestion of Noctiluca, micro-fraction contribution (83.7%) was significantly higher compared to the nano- (15.7%) and pico-fractions (0.58%). On the other hand, copepods showed the highest positive electivity for the phytoplankton nano-fraction (av. 0.38 ± 0.04) followed by micro- (av. -0.17 ± 0.05) and pico-fractions (av. -0.35 ± 0.05). Similarly, in total ingestion of copepods, nano-fraction (69.7%) was the highest followed by micro

  6. 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, doi:10.1594/PANGAEA.862968.

  7. Production and use of copepods in marine fish larviculture

    DEFF Research Database (Denmark)

    Støttrup, Josianne; Norsker, N.H.

    1997-01-01

    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...... 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...

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

    DEFF Research Database (Denmark)

    Jiang, H.; Kiørboe, Thomas

    2011-01-01

    the imposed flow fields and associated energetics of jumps by means of computational fluid dynamics simulations by modeling the copepod as a self-propelled body. The computational fluid dynamics simulation was validated by particle image velocimetry data. The flow field generated by a repositioning jump...... 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...

  9. Carotenoid metabolic profiling and transcriptome-genome mining reveal functional equivalence among blue-pigmented copepods and appendicularia.

    Science.gov (United States)

    Mojib, Nazia; Amad, Maan; Thimma, Manjula; Aldanondo, Naroa; Kumaran, Mande; Irigoien, Xabier

    2014-06-01

    The tropical oligotrophic oceanic areas are characterized by high water transparency and annual solar radiation. Under these conditions, a large number of phylogenetically diverse mesozooplankton species living in the surface waters (neuston) are found to be blue pigmented. In the present study, we focused on understanding the metabolic and genetic basis of the observed blue phenotype functional equivalence between the blue-pigmented organisms from the phylum Arthropoda, subclass Copepoda (Acartia fossae) and the phylum Chordata, class Appendicularia (Oikopleura dioica) in the Red Sea. Previous studies have shown that carotenoid-protein complexes are responsible for blue coloration in crustaceans. Therefore, we performed carotenoid metabolic profiling using both targeted and nontargeted (high-resolution mass spectrometry) approaches in four different blue-pigmented genera of copepods and one blue-pigmented species of appendicularia. Astaxanthin was found to be the principal carotenoid in all the species. The pathway analysis showed that all the species can synthesize astaxanthin from β-carotene, ingested from dietary sources, via 3-hydroxyechinenone, canthaxanthin, zeaxanthin, adonirubin or adonixanthin. Further, using de novo assembled transcriptome of blue A. fossae (subclass Copepoda), we identified highly expressed homologous β-carotene hydroxylase enzymes and putative carotenoid-binding proteins responsible for astaxanthin formation and the blue phenotype. In blue O. dioica (class Appendicularia), corresponding putative genes were identified from the reference genome. Collectively, our data provide molecular evidences for the bioconversion and accumulation of blue astaxanthin-protein complexes underpinning the observed ecological functional equivalence and adaptive convergence among neustonic mesozooplankton. © 2014 The Authors. Molecular Ecology Published by John Wiley & Sons Ltd.

  10. 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...

  11. Copepod carcasses in a tropical estuary during different hydrographical settings

    Digital Repository Service at National Institute of Oceanography (India)

    Jyothibabu, R.; Jagadeesan, L.; Lallu, K.R.

    Dead copepods (carcasses) are widespread in aquatic systems, but their scientific quantification is rare due to the difficulty in discriminating them from live ones. In this paper, we hypothesized that due to large spatial and temporal changes...

  12. 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...... the copepod resumed feeding for a few hours, indicating the secretion of acidic digestive fluid. A copepod feeding on Thalassiosira weissflogii (diatom) had slightly lower pH than that feeding on Rhodomonas salina (cryptophyte). Oxygen was undersaturated in the gut of both C. hyperboreus and C. glacialis......, 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...

  13. 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...

  14. Copepod behavior response to Burgers' vortex treatments mimicking turbulent eddies

    Science.gov (United States)

    Elmi, D.; Webster, D. R.; Fields, D. M.

    2017-11-01

    Copepods detect hydrodynamic cues in the water by their mechanosensory setae. We expect that copepods sense the flow structure of turbulent eddies in order to evoke behavioral responses that lead to population-scale distribution patterns. In this study, the copepods' response to the Burgers' vortex is examined. The Burgers' vortex is a steady-state solution of three-dimensional Navier-Stokes equations that allows us to mimic turbulent vortices at the appropriate scale and eliminate the stochastic nature of turbulence. We generate vortices in the laboratory oriented in the horizontal and vertical directions each with four intensity levels. The objective of including vortex orientation as a parameter in the study is to quantify directional responses that lead to vertical population distribution patterns. The four intensity levels correspond to target vortex characteristics of eddies corresponding to the typical dissipative vortices in isotropic turbulence with mean turbulent dissipation rates in the range of 0.002 to 0.25 cm2/s3. These vortices mimic the characteristics of eddies that copepods most likely encounter in coastal zones. We hypothesize that the response of copepods to hydrodynamic features depends on their sensory architecture and relative orientation with respect to gravity. Tomo-PIV is used to quantify the vortex circulation and axial strain rate for each vortex treatment. Three-dimensional trajectories of the copepod species Calanus finmarchicus are analyzed to examine their swimming kinematics in and around the vortex to quantify the hydrodynamic cues that trigger their behavior.

  15. Redescription of the poorly known planktonic copepod Pontellopsis lubbockii (Giesbrecht, 1889 (Pontellidae from the Eastern Tropical Pacific with a key to species

    Directory of Open Access Journals (Sweden)

    Eduardo Suarez-Morales

    2012-10-01

    Full Text Available During a survey of the epipelagic zooplankton carried out off the coast of the Mexican states of Jalisco and Colima, in the Eastern Tropical Pacific, female and male specimens of the poorly known calanoid copepod Pontellopsis lubbockii (Giesbrecht, 1889 were collected. Because previous descriptions and illustrations are largely incomplete and have caused some taxonomical confusion, this species is fully redescribed from specimens from the Mexican Pacific. The species has some characters that have been overlooked, but those related to the female genital double-somite are the most striking, it has two conical dorsal protuberances and a long ventral spiniform process unique of this species. The mouthparts of this species have not been hitherto described and figured, the flexible terminal setae of legs 3 and 4 is noteworthy. The male general morphology agrees in general with previous data, but new details of the leg 5 and geniculate antennule are added. Its mouthparts, with strong, serrate setae on the maxillae and maxillules, and a strong mandibular edge, suggest that this is a predator form. A dichotomous key for the identification of males and females of the species of Pontellopsis known from the Eastern Tropical Pacific is included.

  16. Redescription of the poorly known planktonic copepod Pontellopsis lubbockii (Giesbrecht, 1889) (Pontellidae) from the Eastern Tropical Pacific with a key to species.

    Science.gov (United States)

    Suárez-Morales, Eduardo; Kozak, Eva

    2012-01-01

    During a survey of the epipelagic zooplankton carried out off the coast of the Mexican states of Jalisco and Colima, in the Eastern Tropical Pacific, female and male specimens of the poorly known calanoid copepod Pontellopsis lubbockii (Giesbrecht, 1889) were collected. Because previous descriptions and illustrations are largely incomplete and have caused some taxonomical confusion, this species is fully redescribed from specimens from the Mexican Pacific. The species has some characters that have been overlooked, but those related to the female genital double-somite are the most striking, it has two conical dorsal protuberances and a long ventral spiniform process unique of this species. The mouthparts of this species have not been hitherto described and figured, the flexible terminal setae of legs 3 and 4 is noteworthy. The male general morphology agrees in general with previous data, but new details of the leg 5 and geniculate antennule are added. Its mouthparts, with strong, serrate setae on the maxillae and maxillules, and a strong mandibular edge, suggest that this is a predator form. A dichotomous key for the identification of males and females of the species of Pontellopsis known from the Eastern Tropical Pacific is included.

  17. Redescription of the poorly known planktonic copepod Pontellopsis lubbockii (Giesbrecht, 1889) (Pontellidae) from the Eastern Tropical Pacific with a key to species

    Science.gov (United States)

    Suárez-Morales, Eduardo; Kozak, Eva

    2012-01-01

    Abstract During a survey of the epipelagic zooplankton carried out off the coast of the Mexican states of Jalisco and Colima, in the Eastern Tropical Pacific, female and male specimens of the poorly known calanoid copepod Pontellopsis lubbockii (Giesbrecht, 1889) were collected. Because previous descriptions and illustrations are largely incomplete and have caused some taxonomical confusion, this species is fully redescribed from specimens from the Mexican Pacific. The species has some characters that have been overlooked, but those related to the female genital double-somite are the most striking, it has two conical dorsal protuberances and a long ventral spiniform process unique of this species. The mouthparts of this species have not been hitherto described and figured, the flexible terminal setae of legs 3 and 4 is noteworthy. The male general morphology agrees in general with previous data, but new details of the leg 5 and geniculate antennule are added. Its mouthparts, with strong, serrate setae on the maxillae and maxillules, and a strong mandibular edge, suggest that this is a predator form. A dichotomous key for the identification of males and females of the species of Pontellopsis known from the Eastern Tropical Pacific is included. PMID:23372406

  18. 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...... of probiotics for improving the fitness of copepod cultures; and 6) encourage copepod producers/retailers to use/develop an efficient sales and marketing strategy....

  19. Copepod predation on Anopheles quadrimaculatus larvae in rice fields.

    Science.gov (United States)

    Marten, G G; Nguyen, M; Ngo, G

    2000-06-01

    Cyclopoid copepods and mosquito larvae were surveyed in southwestern Louisiana rice fields. Almost every rice field had a natural population of Mesocyclops ruttneri, Acanthocylops vernalis, or Macrocyclops albidus. Judging from the abundance of pupae, 29% of the fields were responsible for virtually all Anopheles quadrimaculatus production, apparently because larval mortality suppressed production in the other fields. Mesocyclops ruttneri had the strongest negative association of naturally occurring copepod populations with An. quadrimaculatus larvae, though a few fields with M. ruttneri had substantial Anopheles production. Macrocyclops albidus, M. ruttneri, Mesocyclops edax, and Mesocyclops longisetus were introduced to experimental rice field plots. It took two months for the introduced copepods to build up their numbers; Anopheles larvae then disappeared from all treated plots while larvae continued to be present in the adjacent control field. Copepods were observed to kill the following number of first instar An. quadrimaculatus larvae in the laboratory: Mesocyclops ruttneri (36 larvae/day), Macrocyclops albidus (23 larvae/day), Mesocyclops longisetus (24 larvae/day), and Acanthocyclops vernalis (15 larvae/day). It is concluded that introducing select species of copepods and encouraging their populations offer possibilities for contributing to Anopheles control in rice fields.

  20. A simple method for cultivating freshwater copepods used in biological control of Aedes aegypti.

    Science.gov (United States)

    Suarez, M F; Marten, G G; Clark, G G

    1992-12-01

    A simple method for indoor and outdoor cultivation of Mesocyclops aspericornis, Macrocyclops albidus and Mesocyclops n. sp. copepods is presented. This method utilizes Chilomonas sp., Paramecium caudatum and fresh lettuce as food sources for copepod cultures. Steps for initiating and maintaining copepod cultures are provided.

  1. 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...

  2. 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

    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...

  3. Interactions between benthic copepods, bacteria and diatoms promote nitrogen retention in intertidal marine sediments.

    Directory of Open Access Journals (Sweden)

    Willem Stock

    Full Text Available The present study aims at evaluating the impact of diatoms and copepods on microbial processes mediating nitrate removal in fine-grained intertidal sediments. More specifically, we studied the interactions between copepods, diatoms and bacteria in relation to their effects on nitrate reduction and denitrification. Microcosms containing defaunated marine sediments were subjected to different treatments: an excess of nitrate, copepods, diatoms (Navicula sp., a combination of copepods and diatoms, and spent medium from copepods. The microcosms were incubated for seven and a half days, after which nutrient concentrations and denitrification potential were measured. Ammonium concentrations were highest in the treatments with copepods or their spent medium, whilst denitrification potential was lowest in these treatments, suggesting that copepods enhance dissimilatory nitrate reduction to ammonium over denitrification. We hypothesize that this is an indirect effect, by providing extra carbon for the bacterial community through the copepods' excretion products, thus changing the C/N ratio in favour of dissimilatory nitrate reduction. Diatoms alone had no effect on the nitrogen fluxes, but they did enhance the effect of copepods, possibly by influencing the quantity and quality of the copepods' excretion products. Our results show that small-scale biological interactions between bacteria, copepods and diatoms can have an important impact on denitrification and hence sediment nitrogen fluxes.

  4. Interactions between Benthic Copepods, Bacteria and Diatoms Promote Nitrogen Retention in Intertidal Marine Sediments

    Science.gov (United States)

    Stock, Willem; Heylen, Kim; Sabbe, Koen; Willems, Anne; De Troch, Marleen

    2014-01-01

    The present study aims at evaluating the impact of diatoms and copepods on microbial processes mediating nitrate removal in fine-grained intertidal sediments. More specifically, we studied the interactions between copepods, diatoms and bacteria in relation to their effects on nitrate reduction and denitrification. Microcosms containing defaunated marine sediments were subjected to different treatments: an excess of nitrate, copepods, diatoms (Navicula sp.), a combination of copepods and diatoms, and spent medium from copepods. The microcosms were incubated for seven and a half days, after which nutrient concentrations and denitrification potential were measured. Ammonium concentrations were highest in the treatments with copepods or their spent medium, whilst denitrification potential was lowest in these treatments, suggesting that copepods enhance dissimilatory nitrate reduction to ammonium over denitrification. We hypothesize that this is an indirect effect, by providing extra carbon for the bacterial community through the copepods' excretion products, thus changing the C/N ratio in favour of dissimilatory nitrate reduction. Diatoms alone had no effect on the nitrogen fluxes, but they did enhance the effect of copepods, possibly by influencing the quantity and quality of the copepods' excretion products. Our results show that small-scale biological interactions between bacteria, copepods and diatoms can have an important impact on denitrification and hence sediment nitrogen fluxes. PMID:25360602

  5. 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

  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. 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

  8. Predator and prey perception in copepods due to hydromechanical signals

    DEFF Research Database (Denmark)

    Kiørboe, Thomas; Visser, Andre

    1999-01-01

    large and rapidly swimming/sinking prey particles, and (4) that the model can accommodate the 3 orders of magnitude variation in clearance rates observed in the copepod Oithona similis feeding on motile protists and sinking particles. We finally discuss the implications of hydromechanical predator...... and prey perception to trophic interactions and vertical particle fluxes, and suggest important research questions that may be addressed....

  9. The Physiology and Ecology of Diapause in Marine Copepods

    Science.gov (United States)

    Baumgartner, Mark F.; Tarrant, Ann M.

    2017-01-01

    Diapause is a type of dormancy that requires preparation, typically precedes the onset of unfavorable conditions, and necessitates a period of arrest before development can proceed. Two ecologically important groups of copepods have incorporated diapausing stages into their life histories. In freshwater, estuarine, and coastal environments, species within the Centropagoidea superfamily can produce resting eggs containing embryos that may be quiescent, diapausing, or in some intermediate state. Resting eggs sink into the sediments, remain viable over months to years, and form a reservoir from which the planktonic population is reestablished. In coastal and oceanic environments, copepods within the Calanidae and Eucalanidae families can enter diapause during late juvenile (copepodid) or adult stages. These copepods accumulate large amounts of lipids before they migrate into deep water and diapause for several months. Through respiration, diapausing copepods may sequester more carbon in the deep ocean than any other biogeochemical process, and changes in diapause phenology associated with climate change (particularly reduction in diapause duration) could have a significant impact not only on regional ecosystems, but on global climate as well.

  10. Copepod composition, abundance and diversity in Makupa Creek ...

    African Journals Online (AJOL)

    Daisy Ouya

    . 34° 40' E. 4° 02' S. Industrial area. Bathymetry (m). Sampling stations. KEY ... Field sampling was not conducted in October; Chlorophyll-a was not sampled in January and May. Fig. 3. Monthly abundance (no./m3) of all the copepods counted ...

  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 correlation...

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

    Digital Repository Service at National Institute of Oceanography (India)

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

    )forming 91.9 to 96.1 c of the total copepod population and constituted mainly by 4 species of Pontellopsis was recorded The species in order of abundance were Pontella spinipes Giesbrecht Pontellopsis regalis (Dana), Pontella princeps Dana and P...

  13. Copepod reproduction is unaffected by diatom aldehydes or lipid composition

    DEFF Research Database (Denmark)

    Dutz, Jörg; Koski, Marja; Jonasdottir, Sigrun

    2008-01-01

    We investigated whether reduced reproductive success of copepods fed with diatoms was related to nutritional imbalances with regard to essential lipids or to the production of inhibitory aldehydes. In 10-d laboratory experiments, feeding, egg production, egg hatching success, and fecal pellet...

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

    DEFF Research Database (Denmark)

    Hirst, A.G.; Kiørboe, Thomas

    2002-01-01

    copepod longevity with predation-free laboratory longevity, we are able to make the first global approximations of the natural rates of predation mortality. Predation and total mortality both increase with increasing temperature; however, the proportion that predation makes of total adult mortality...

  15. 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...

  16. Three species of piscine parasitic copepods from southern African ...

    African Journals Online (AJOL)

    1992-09-04

    Sep 4, 1992 ... tuna, beskryf. Verskeie moriologiese variasies van ander beskrywings word in al drie spesies aangetoon. The three species of piscine parasitic copepods described here represent new and only descriptions from southern. African marine fish. Lepeopthirius nordmanni (Edwards,. 1840) was sampled from ...

  17. 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-invasive....... The importance of carcass associated denitrification could be highly significant in O2 depleted environments such as Oxygen Minimum Zones (OMZ...

  18. Macroevolutionary patterns of sexual size dimorphism in copepods

    DEFF Research Database (Denmark)

    Hirst, Andrew G.; Kiørboe, Thomas

    2014-01-01

    the larger sex in copepod species. Comparing clades that vary by four orders of magnitude in their degree of dimorphism, we show that isometry is widespread. As such we find no support for either RR or for covariation between allometry and SSD. Our results suggest that selection on both sexes has been...

  19. Spatial diversity of nematode and copepod genera of the coral ...

    African Journals Online (AJOL)

    Differential susceptibility to hydrodynamic disturbance is proposed as an explanation. Coral fragments contributed considerably to the total diversity in terms of the number of nematode and copepod genera. It is therefore recommended to include this microhabitat in future biodiversity studies on tropical lagoons. Trends in ...

  20. 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...

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

    DEFF Research Database (Denmark)

    Lombard, Fabien; Koski, Marja; Kiørboe, Thomas

    2013-01-01

    the behavior of males tracking pheromone trails, although with a lower tracking velocity. Upon finding a house, the copepod would attach for a short period (10–30 s) and feed intensively. Due to short residence times, daily feeding rates were moderate. Our results demonstrate that even T. longicornis...

  2. Copepod carcasses in a tropical estuary during different hydrographical settings.

    Science.gov (United States)

    Jyothibabu, R; Jagadeesan, L; Lallu, K R

    2015-10-01

    Dead copepods (carcasses) are widespread in aquatic systems, but their scientific quantification is rare due to the difficulty in discriminating them from live ones. In this paper, we hypothesized that due to large spatial and temporal changes in hydrography in the Cochin backwaters, the percentage of copepod carcasses in the system could also change significantly on a spatial and temporal scale. In order to understand this aspect, we quantified the live and dead copepods in the Cochin backwaters under different hydrographical settings based on live and mortal staining technique. The most prominent temporal hydrographical feature during the study period was the large decline in salinity across the system, which was more pronounced downstream (15-20 units) and was caused by the large freshwater influx associated with the southwest monsoon. During the entire sampling period, copepod carcasses were pervasive all over the study area with large spatial and temporal variations in their percentage contribution (2.5-35.8 %) to the total community abundance. During all sampling, carcasses concentrated more in the downstream region, with maximum turbidity (16.5-35.8 %), than in the upstream region (2.5-14.5 %). The percentage of carcasses was the highest during the onset of the southwest monsoon (av. 23.64 ± 8.09 %), followed by the pre-southwest monsoon (av. 13.59 ± 6.72 %) and southwest monsoon (av. 8.75 ± 4.14 %). During the onset of the southwest monsoon, copepod carcasses in the downstream were contributed by ∼80 % high saline and ∼15 % low saline species, indicating a salinity shock-induced mortality. On the other hand, the cumulative effect of the long residence time of the Cochin backwaters and high partial predation rate of carnivores contributed to the high abundance of carcasses during the pre-monsoon.

  3. Feeding ecology of the transparent goby Aphia minuta (Pisces, Gobiidae in the northwestern Adriatic Sea

    Directory of Open Access Journals (Sweden)

    Mario La Mesa

    2008-03-01

    Full Text Available The feeding ecology of the transparent goby Aphia minuta was examined in spring (May 2003 in the coastal waters off Comacchio, in the northwestern Adriatic Sea. Stomach content analysis indicated A. minuta to be a planktivorous species, feeding exclusively on pelagic invertebrates. The diet composition was dominated by the calanoid copepods Acartia clausi and Temora longicornis, followed in decreasing order of importance by other copepods (especially calanoids and Oncaea spp. and larvae of decapods, polychaetes and bivalves. A. minuta exhibited a generalistic feeding strategy with a relatively broad niche width. Abundant taxa in the environment, such as A. clausi and T. longicornis, were seldom selected, whereas rare taxa, such as larvae of polychaetes and decapods, were highly selected. According to the observed ontogenetic shift in diet, small-size individuals relied preferentially on juvenile T. longicornis and Oncaea spp., whereas large-sized specimens consumed preferably A. clausi and calanoids. The positive relationship found between prey and fish size may help to mitigate the intraspecific competition for food resources.

  4. Foraging response and acclimation of ambush feeding and feeding-current feeding copepods to toxic dinoflagellates

    DEFF Research Database (Denmark)

    Xu, Jiayi; Nielsen, Lasse Tor; Kiørboe, Thomas

    2018-01-01

    Copepods exposed to toxic algae in “black box” incubation experiments show highly varied responses, but the mechanisms cannot be revealed from such experiments and the implications to copepod and phytoplankton population dynamics consequently not evaluated. Here, we use direct video observations...... reticulatum. We hypothesize (1) that ambush feeders are less affected by toxic algae than feeding-current feeders, (2) that copepods acclimate to the toxic algae, and (3) that phytoplankton cells previously exposed to copepod cues elicit stronger responses. Both copepod species consumed the toxic algae...... the copepods to survive harmful algal blooms. However, the implications to algal population dynamics are species/strains specific, with only prey selection providing the toxic algae with a competitive advantage...

  5. Community structure of harpacticoid copepods from the southeast continental shelf of India

    OpenAIRE

    K.G.M.T. Ansari; P.S Lyla; S. Ajmal Khan, et al.

    2013-01-01

    The study is the first attempt aiming to assess the composition and number of harpacticoid copepods in the southeast continental shelf of India (Bay of Bengal). 39 putative species of copepods were identified belongings to 29 genera in 17 families. Copepod density registered gradual decrease with increase in depth and sediment was sandy to silty nature. Principal Component Analysis (PCA), clearly documents significant variability within the abiotic variables with total variation of 92.9%. Cop...

  6. Resting eggs in free living marine and estuarine copepods

    DEFF Research Database (Denmark)

    Holm, Mark Wejlemann; Kiørboe, Thomas; Brun, Philipp Georg

    2017-01-01

    Marine free living copepods can survive harsh periods and cope with seasonal fluctuations in environmental conditions using resting eggs (embryonic dormancy). Laboratory experiments show that temperature is the common driver for resting egg production. Hence, we hypothesize (i) that seasonal...... temperature variation, rather than variation in food abundance is the main driver for the occurrence of the resting eggs strategy in marine and estuarine copepod species; and (ii) that the thermal boundaries of the distribution determine where resting eggs are produced and whether they are produced to cope...... with warm or cold periods. We compile literature information on the occurrence of resting egg production and relate this to spatio-temporal patterns in sea surface temperature and chlorophyll a concentration obtained from satellite observations. We find that the production of resting eggs has been reported...

  7. 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.

    on ICM: Lessons Learned to Address New Challenges 30 Oct - 03 Nov 2013, Marmaris, Turkey, E. Ozhan (Editor) Decline in Biodiversity of Copepods in Coastal Waters of Mumbai Rosamma Stephen'<', K.V. Jayalakshmy'<' and Vij ayalakshmi R. Nair(3) (1) National... contributed significantly. The species encountered in the marine zone are Canthocalanus pauper, Eucalanus subcrassus, Candacia discaudata and Labodocera spp. The percentage of Pseudodiaptomus spp increased towards the polluted interior stations in both sectors...

  8. Zooplankton motile behavior: traits and trade-offs in planktonic copepods

    DEFF Research Database (Denmark)

    van Someren Gréve, Hans

    Research on planktonic copepod ecology is vital to understand the factors controlling marine food web dynamics since copepods are the major components of zooplankton communities and the main link between trophic levels in marine environments. Despite their taxonomic diversity, copepods share...... in zooplankton result in different trade-offs between efficient feeding, mate finding, and predation risk. We experimentally quantified i) swimming behavior, ii) feeding rates on different prey, iii) escape capability and iv) predation risk in various copepod life stages and genders with different motile...

  9. Copepod Behavior Response in an Internal Wave Apparatus

    Science.gov (United States)

    Webster, D. R.; Jung, S.; Haas, K. A.

    2017-11-01

    This study is motivated to understand the bio-physical forcing in zooplankton transport in and near internal waves, where high levels of zooplankton densities have been observed in situ. A laboratory-scale internal wave apparatus was designed to create a standing internal wave for various physical arrangements that mimic conditions observed in the field. A theoretical analysis of a standing internal wave inside a two-layer stratification system including non-linear wave effects was conducted to derive the expressions for the independent variables controlling the wave motion. Focusing on a case with a density jump of 1.0 σt, a standing internal wave was generated with a clean interface and minimal mixing across the pycnocline. Spatial and frequency domain measurements of the internal wave were evaluated in the context of the theoretical analysis. Behavioral assays with a mixed population of three marine copepods were conducted in control (stagnant homogeneous fluid), stagnant density jump interface, and internal wave flow configurations. In the internal wave treatment, the copepods showed an acrobatic, orbital-like motion in and around the internal wave region (bounded by the crests and the troughs of the waves). Trajectories of passive, neutrally-buoyant particles in the internal wave flow reveal that they generally oscillate back-and-forth along fixed paths. Thus, we conclude that the looping, orbital trajectories of copepods in the region near the internal wave interface are due to animal behavior rather than passive transport.

  10. 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.

  11. Community effectiveness of copepods for dengue vector control: systematic review.

    Science.gov (United States)

    Lazaro, A; Han, W W; Manrique-Saide, P; George, L; Velayudhan, R; Toledo, J; Runge Ranzinger, S; Horstick, O

    2015-06-01

    Vector control remains the only available method for primary prevention of dengue. Several interventions exist for dengue vector control, with limited evidence of their efficacy and community effectiveness. This systematic review compiles and analyses the existing global evidence for community effectiveness of copepods for dengue vector control. The systematic review follows the PRISMA statement, searching six relevant databases. Applying all inclusion and exclusion criteria, 11 articles were included. There is evidence that cyclopoid copepods (Mesocyclops spp.) could potentially be an effective vector control option, as shown in five community effectiveness studies in Vietnam. This includes long-term effectiveness for larval and adult control of Ae. aegypti, as well as dengue incidence. However, this success has so far not been replicated elsewhere (six studies, three community effectiveness studies--Costa Rica, Mexico and USA, and three studies analysing both efficacy and community effectiveness--Honduras, Laos and USA), probably due to community participation, environmental and/or biological factors. Judging by the quality of existing studies, there is a lack of good study design, data quality and appropriate statistics. There is limited evidence for the use of cyclopoid copepods as a single intervention. There are very few studies, and more are needed in other communities and environments. Clear best practice guidelines for the methodology of entomological studies should be developed. © 2015 John Wiley & Sons Ltd.

  12. 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

  13. 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...

  14. Fatty acid profiles of algae mark the development and composition of harpacticoid copepods

    NARCIS (Netherlands)

    Caramujo, M.J.; Boschker, H.T.S.; Admiraal, W.

    2008-01-01

    1. The value of algal fatty acids (FA) as diet biomarkers for benthic harpacticoid copepods was investigated. A high proportion of 18:1ω9 and 18:2ω6 FA was observed in the lipid reserve fraction of copepods fed with cyanobacteria. In contrast, a high proportion of 16:1ω7 and ω3 FA (including

  15. 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

    We describe the kinematics of escape jumps in three species of 0.3–3.0 mm-sized planktonic copepods. We find similar kinematics between species with periodically alternating power strokes and passive coasting and a resulting highly fluctuating escape velocity. By direct numerical simulations, we ...... propulsion efficiency, again suggesting that copepods are optimally designed for rapid escape jumps....

  16. 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...

  17. Observations of copepod feeding and vertical distribution under natural turbulent conditions in the North Sea

    DEFF Research Database (Denmark)

    Visser, Andre; Saito, H.; Saiz, E.

    2001-01-01

    We present results of simultaneous measurements of turbulent- dissipation rate, zooplankton vertical distribution and copepod gut pigments in the northern North Sea. Analysis shows that some, but not all, copepods (by species, sex and stage) exhibit significant dependence on turbulence in respect...

  18. Checklist of copepods (Crustacea: Calanoida, Cyclopoida,Harpacticoida) from Wyoming, USA, with new state records

    Science.gov (United States)

    Presentation of a comprehensive checklist of the copepod fauna of Wyoming, USA with 41 species of copepods; based on museum specimens, literature reviews, and active surveillance. Of these species 19 were previously unknown from the state. This checklist includes species in the families Centropagida...

  19. 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 error...... 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......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...

  20. 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

    As a major part of fish larval diet in nature, copepods constitute an appropriate live prey for aquaculture purposes. Considering the difficulty of mastering copepod mass production, studies on their growth performance at different environmental conditions are needed to improve their productivity....... In this study a new selective approach based on temperature control is proposed to improve the physiological (body size, fecundity and lipid storage) performance of copepods. The estuarine copepod Eurytemora affinis known to have a high genetic variance in temperature tolerance was used as a biological model....... 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...

  1. 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.

  2. Hydrodynamics and energetics of jumping copepod nauplii and copepodids

    DEFF Research Database (Denmark)

    Wadhwa, Navish; Andersen, Anders Peter; Kiørboe, Thomas

    2014-01-01

    vortex rings, respectively. Our measurements suggest that copepodids cover a larger distance compared to their body size in each jump and are also hydrodynamically quieter, as the flow disturbance they create attenuates faster with distance. Also, copepodids are energetically more efficient than nauplii...... viscosity and inertia are potentially important, and the Reynolds number changes by an order of magnitude during growth. Thus we expect the life stage related changes experienced by a copepod to result in hydrodynamic and energetic differences, ultimately affecting the fitness. To quantify these differences...

  3. 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

    . However, ferritin expression exhibited a strong increase from days 3 to 5 of quiescence followed by a declined. After 2 weeks of quiescence, development of the embryos recovered by the addition of oxygen and increased temperature. The expression of both genes increased 222-fold for hsp70 and 52-fold...

  4. Morphometric differences in two calanoid sibling species, Boeckella gracilipes and B. titicacae (Crustacea, Copepoda Diferencias morfométricas en dos especies hermanas Boeckella gracilipes y Boeckella titicacae (Crustacea, Copepoda

    Directory of Open Access Journals (Sweden)

    Patricio De los Ríos Escalante

    2012-12-01

    Full Text Available Calanoid copepods are abundant in South American inland waters and include widespread species, such as Boeckella gracilipes (Daday, 1902, which occurs from the Ecuador to Tierra del Fuego Island. This species occurs under various environmental conditions, and is found in oligotrophic lakes in Patagonia (39-54°S and in shallow mountain lakes north of 39°S. The aim of the present study is to conduct a morphometric comparison of male specimens of B. titicacae collected in Titicaca and B. gracilipes collected in Riñihue lakes, with a third population of B. gracilipes collected in shallow ponds in Salar de Surire. Titicaca and Riñihue lakes are stable environments, whereas Salar de Surire is an extreme environment. These ponds present an extreme environment due to high exposure to solar radiation and high salinity levels. The results of the study revealed differences among the three populations. These results agree well with systematic descriptions in the literature on differences between the populations of Titicaca and Riñihue lakes, and population of Salar de Surire differs slightly from the other two populations. It is probable that the differences between the population of Salar de Surire and the other two populations result from the extreme environment in Salar de Surire. High exposure to solar radiation, high salinity and extreme variations in temperature enhance genetic variations that are consequently expressed in morphology.Los copépodos calanoideos son abundantes en aguas continentales sudamericanas e incluyen especies de amplia distribución geográfica como Boeckella gracilipes (Daday, 1902 que se encuentra desde Ecuador hasta la isla de Tierra del Fuego. Esta especie vive bajo varias condiciones ambientales, y se encuentra en lagos oligotróficos en la Patagonia (39-54°S y en lagunas superficiales de montaña al norte de los 39°S. El objetivo del presente trabajo es realizar un estudio comparativo morfométrico de machos de B

  5. 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.

  6. Does sediment grain size affect diatom grazing by harpacticoid copepods?

    Science.gov (United States)

    De Troch, Marleen; Houthoofd, Lieven; Chepurnov, Victor; Vanreusel, Ann

    2006-04-01

    Estuarine soft sediments support a diverse group of eukaryotic and prokaryotic organisms though the role of the sediment per se for the functioning of these organisms remains largely unknown. The present study aimed to test the effect of sediment grain size on the grazing activities of harpacticoid copepods. In controlled experiments, two common intertidal harpacticoid species (Paramphiascella fulvofasciata and Nitokra spinipes) were each offered a mix of two benthic diatom species (Navicula phyllepta and Seminavis robusta) in different sedimentary conditions. Several microcosms were created using a variety of sediment types, including fine silt (grained sands (125-250, 250-450, 100-300 microm), artificial 'sediments' of glass beads (250-500, 2000 microm) and even the absence of sediment was tested. The diatoms were enriched in the stable carbon (13)C to facilitate tracing in the harpacticoids. Both copepod species were able to graze on the diatoms with highest uptake when sediment was absent. In contrast, both harpacticoid species showed no uptake in silty conditions. In general, grazing was favoured when mean sediment grain size increased. The strong negative effect of fine grains on the grazer's efficiency can be explained by the resulting differences in the structure (and accessibility) of the diatom biofilm on the one hand and the mobility of the grazer on the other hand. In view of the subtle equilibrium between primary producers and grazers, these results might have important implications for the effect of siltation of tidal flats due to, e.g., human activities.

  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

    and from an artificial flow field, and the results were used in a model of hydrodynamic disturbance generated by a predator. The copepods detected mysids from a significantly larger distance than they detected sticklebacks (0.45 and 0.24 cm, respectively). Consequently, the capture success...... 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. 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......: 50% of chla was 50 .mu.m, averaged for all stations. Chlorophyll ranged from 0.2 to 2.5 .mu.g l-1 at most depths and stations. Specific growth rates of copepods averaged 0.10 day-1 for adult females and 0.27 day-1 for juveniles. The latter...

  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...... concentrations, and that chemical prey perception is feasible if prey cells release dissolved organic material in short-lasting but intense bursts. We demonstrate that mechanoreception at a very short range is sufficient to sustain a living, even in a dilute ocean. Further, if chemoreception requires that prey...... and Centropages hamatus, offered a 45-μm sized dinoflagellate at very low concentration. The observed short prey detection distances, up to a few prey cell radii, are consistent with mechanoreception and we argue briefly that near-field mechanoreception is the most likely and common prey perception mechanism...

  10. 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...... 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...... encounter food by scavenging, which also allows for some food capture inefficiency. Jump-sink types rely on motile food. We demonstrate how diffusivity of motile prey may account for observed clearance rates for jump-sink types, which seem to employ 2 strategies. Infrequent jumping as observed in many...

  11. Trait biogeography of marine copepods - an analysis across scales

    DEFF Research Database (Denmark)

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

    2016-01-01

    %) explained by key environmental drivers. Body size, for example decreases with temperature, confirming the temperature-size rule, but surprisingly also with productivity, possibly driven by food-chain length and size-selective predation. Patterns unrelated to environmental predictors may originate from......Functional traits, rather than taxonomic identity, determine the fitness of individuals in their environment: traits of marine organisms are therefore expected to vary across the global ocean as a function of the environment. Here, we quantify such spatial and seasonal variations based on extensive...... empirical data and present the first global biogeography of key traits (body size, feeding mode, relative offspring size and myelination) for pelagic copepods, the major group of marine zooplankton. We identify strong patterns with latitude, season and between ocean basins that are partially (c. 50...

  12. 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...

  13. 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.

    The occurrence of Vibrio cholerae in water, sediment and copepods was studied over a wide range of salinity using conventional and polymerase chain reaction (PCR) techniques in the Cochin backwaters. V. cholerae occurred either as culturable or non-culturable...

  14. 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...

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

    Digital Repository Service at National Institute of Oceanography (India)

    Goswami, S.C.

    repopulation and proliferation with a gradual salinity recovery, attaining maximum species diversity during the dry premonsoon months Spatial and temporal variations in the occurrence and abundance of copepod species are discussed...

  16. 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

  17. 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...

  18. EFFECT OF MICROALGAE ON GROWTH AND FATTY ACID PROFILES OF HARPACTICOID COPEPOD, Tisbe holothuriae

    Directory of Open Access Journals (Sweden)

    Gede Suwarthama Sumiarsa

    2009-12-01

    Full Text Available Growth of marine copepods is influenced by feed. The purposes of this trial were to observe both growth and fatty acid compositions of harpacticoid copepod nauplii, Tisbe holothuriae by feeding with several microalgal species in laboratory: (A Isochrysis tahiti; (B Nannochloropsis oculata; (C Rhodomonas sp., and (D Tetraselmis chuii. The trial was carried out for 35 days with randomized complete design and triplicates in each treatment. The results showed that final copepod nauplii densities were not significantly different (P>0.05 in all treatments. However, lipid content of copepod nauplii fed with T. chuii was significantly higher (P<0.05 compared to that of other treatments while fatty acid profiles of EPA, DHA and DHA/EPA ratios showed both insignificant and significant differences among treatments.

  19. 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...

  20. 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

    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......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...... 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...

  1. Gender-specific feeding rates in planktonic copepods with different feeding behavior

    DEFF Research Database (Denmark)

    van Someren Gréve, Hans; Almeda, Rodrigo; Lindegren, Martin

    2017-01-01

    copepods, particularly in ambush feeders, where the males must sacrifice feeding for mate searching. We conducted gender-specific functional feeding response experiments using prey of different size and motility. In most cases, gender-specific maximum ingestion and clearance rates were largely explained......Planktonic copepods have sexually dimorphic behaviors, which can cause differences in feeding efficiency between genders. Copepod feeding rates have been studied extensively but most studies have focused only on females. In this study, we experimentally quantified feeding rates of males and females...... in copepods with different feeding behavior: ambush feeding (Oithona nana), feeding-current feeding (Temora longicornis) and cruising feeding (Centropages hamatus). We hypothesize that carbon-specific maximum ingestion rates are similar between genders, but that maximum clearance rates are lower for male...

  2. The fluid physics of signal perception by mate-tracking copepods.

    OpenAIRE

    Yen, J; Weissburg, M J; Doall, M H

    1998-01-01

    Within laboratory-induced swarms of the marine copepod Temora longicornis, the male exhibits chemically mediated trail-following behaviour, concluding with fluid mechanical provocation of the mate-capture response. The location and structure of the invisible trail were determined by examining the specific behaviour of the female copepods creating the signal, the response of the male to her signal, and the fluid physics of signal persistence. Using the distance of the mate-tracking male from t...

  3. 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.

  4. Nutritional quality of two cyanobacteria : How rich is 'poor' food?

    DEFF Research Database (Denmark)

    Schmidt, K.; Jonasdottir, Sigrun

    1997-01-01

    Cyanobacteria have often been described to be nutritionally inadequate and to interfere with zooplankton feeding. In laboratory experiments we offered 2 cyanobacteria, a unicellular Microcystis aeruginosa strain and the filamentous Nodularia sprumigena, to the calanoid copepod Acartia tonsa...... as the sole diet and in food mixtures with the nutritious diatom Thalassiosira weissflogii. Egg production was used as criterion of food quality. The use of cyanobacteria alone was an insufficient diet. However, with increasing additions of M. aeruginosa and N. spumigena to the diatom, different effects were...... observed. Large additions of cyanobacteria resulted in lower egg production and often in elevated mortality of the females, but small additions of M. aeruginosa caused an increase of about 25 % in egg production compared to a pure diatom diet. The influence of similar low concentrations of N. spumigena...

  5. Importance and nutritional value of large ciliates for the reproduction of Acartia clausi during the post spring-bloom period in the North Sea

    DEFF Research Database (Denmark)

    Dutz, Jörg; Peters, J.

    2008-01-01

    Shipboard experiments were performed to examine the qualitative importance of large marine microzooplankton for the reproduction of Acartia clausi in the North Sea. Feeding and egg production were compared in 2 treatments in which females were fed natural seston or natural seston selectively...... enriched with large prey (> 20 mu m). The mineral (C, N) and lipid contents of the food suspensions were determined for size-fractionated samples to characterize the nutritional composition of prey. Large oligotrich ciliates and Strobiliidae dominated the seston biomass. Ciliates, particularly...... of the mineral and lipid content confirmed a high seston nutritional quality. The 20 to 48 mu m fraction reflected the composition of female diets and indicated an enrichment of N and polyunsaturated fatty acids (PUFA) in the diet compared to total seston. The fraction > 48 mu m consisted mostly of ciliates...

  6. 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.

  7. Trait biogeography of marine copepods - an analysis across scales.

    Science.gov (United States)

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

    2016-12-01

    Functional traits, rather than taxonomic identity, determine the fitness of individuals in their environment: traits of marine organisms are therefore expected to vary across the global ocean as a function of the environment. Here, we quantify such spatial and seasonal variations based on extensive empirical data and present the first global biogeography of key traits (body size, feeding mode, relative offspring size and myelination) for pelagic copepods, the major group of marine zooplankton. We identify strong patterns with latitude, season and between ocean basins that are partially (c. 50%) explained by key environmental drivers. Body size, for example decreases with temperature, confirming the temperature-size rule, but surprisingly also with productivity, possibly driven by food-chain length and size-selective predation. Patterns unrelated to environmental predictors may originate from phylogenetic clustering. Our maps can be used as a test-bed for trait-based mechanistic models and to inspire next-generation biogeochemical models. © 2016 John Wiley & Sons Ltd/CNRS.

  8. The genome of the Antarctic-endemic copepod, Tigriopus kingsejongensis.

    Science.gov (United States)

    Kang, Seunghyun; Ahn, Do-Hwan; Lee, Jun Hyuck; Lee, Sung Gu; Shin, Seung Chul; Lee, Jungeun; Min, Gi-Sik; Lee, Hyoungseok; Kim, Hyun-Woo; Kim, Sanghee; Park, Hyun

    2017-01-01

    The Antarctic intertidal zone is continuously subjected to extremely fluctuating biotic and abiotic stressors. The West Antarctic Peninsula is the most rapidly warming region on Earth. Organisms living in Antarctic intertidal pools are therefore interesting for research into evolutionary adaptation to extreme environments and the effects of climate change. We report the whole genome sequence of the Antarctic-endemic harpacticoid copepod Tigriopus kingsejongensi . The 37 Gb raw DNA sequence was generated using the Illumina Miseq platform. Libraries were prepared with 65-fold coverage and a total length of 295 Mb. The final assembly consists of 48 368 contigs with an N50 contig length of 17.5 kb, and 27 823 scaffolds with an N50 contig length of 159.2 kb. A total of 12 772 coding genes were inferred using the MAKER annotation pipeline. Comparative genome analysis revealed that T. kingsejongensis -specific genes are enriched in transport and metabolism processes. Furthermore, rapidly evolving genes related to energy metabolism showed positive selection signatures. The T. kingsejongensis genome provides an interesting example of an evolutionary strategy for Antarctic cold adaptation, and offers new genetic insights into Antarctic intertidal biota.

  9. Trampling on coral reefs: tourism effects on harpacticoid copepods

    Science.gov (United States)

    Sarmento, V. C.; Santos, P. J. P.

    2012-03-01

    Human trampling is a common type of disturbance associated with outdoor recreational activities in coastal ecosystems. In this study, the effect of trampling on the meiofaunal harpacticoid copepod assemblage inhabiting turfs on a coral reef was investigated. In Porto de Galinhas, northeastern Brazil, reef formations near the beach are one of the main touristic destinations in the country. To assess trampling impact, two areas were compared: a protected area and an area subject to intensive tourism. Densities of total Harpacticoida and of the most abundant harpacticoid species showed strong reductions in the trampled area. An analysis of covariance revealed that the loss of phytal habitat was not the main source of density reductions, showing that trampling affected the animals directly. In addition, multivariate analysis demonstrated differences in the structure of harpacticoid assemblages between areas. Of the 43 species identified, 12 were detected by the Indicator Species Analyses as being indicators of the protected or trampled areas. Moreover, species richness was reduced in the area open to tourism. At least 25 harpacticoids are new species for science, of these, 20 were more abundant or occurred only in the protected area, while five were more abundant or occurred only in the trampled area; thus, our results highlight the possibility of local extinction of still-unknown species as one of the potential consequences of trampling on coral reefs.

  10. Small copepods structuring mesozooplankton community dynamics in a tropical estuary-coastal system

    Science.gov (United States)

    Rakhesh, M.; Raman, A. V.; Ganesh, T.; Chandramohan, P.; Dehairs, F.

    2013-07-01

    It is important to know the ultimate role of small copepods in structuring mesozooplankton community pattern and diversity on an estuary-coastal gradient. Here multivariate analyses were used to elucidate this in the Godavari estuary, on the east coast of India. During May 2002, corresponding to the spring intermonsoon, mesozooplankton were sampled from 4 GPS fixed stations in the estuarine reaches of River Godavari and 19 in the coastal waters where Godavari enters the Bay of Bengal. There were 91 mesozooplankton taxa represented by 23 divergent groups. Copepods were by far the most prominent in terms of species richness, numerical abundance, and widespread distribution followed by appendicularians. Small copepods of families Paracalanidae, Acartiidae, Oithonidae, Corycaeidae, Oncaeidae, and Euterpinidae dominated. There were differing regional mesozooplankton/copepod communities, that segregated the estuary-coastal sites into different biotic assemblages: Group-I representing the estuary proper, Group-II estuary mouth and near shore, Group-III the intermediate coastal stations and Group-IV the coastal-offshore waters. Alpha (SRp, H', J', Δ*) and beta diversity (MVDISP, β, β-dissimilarity) measures varied noticeably across these assemblages/areas. The significant correlation of small copepod abundance with total mesozooplankton abundance and biomass (mgDM.m-3) in the estuarine (r: 0.40) and coastal (r: 0.46-0.83) waters together with a regression analysis of diversity measures have revealed the importance of small copepods in the overall mesozooplankton/copepod community structure. There were 'characterizing' and 'discriminating' species, responsible for the observed assemblage patterns. Mesozooplankton/copepod community structure and the size-spectra observed during this study indicate an estuarine-coastal gradient in plankton tropho-dynamics that may shift between a microbial dominated system inside the estuary and mixotrophy in the coastal waters. The

  11. 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.

  12. Hg bioaccumulation in marine copepods around hydrothermal vents and the adjacent marine environment in northeastern Taiwan.

    Science.gov (United States)

    Hsiao, Shih-Hui; Fang, Tien-Hsi

    2013-09-15

    The Hg concentration in seawater and copepod samples collected from the area around hydrothermal vents at Kueishan Island and the adjacent marine environment in northeastern Taiwan were analyzed to study Hg bioaccumulation in copepods living in polluted and clean marine environments. The seawater collected from the hydrothermal vent area had an extremely high concentration of dissolved Hg, 50.6-256 ng l(-1). There was slightly higher Hg content in the copepods, 0.08-0.88 μg g(-1). The dissolved Hg concentration in the hydrothermal vent seawater was two to three orders of magnitude higher than that in the adjacent environment. The bioconcentration factor of the studied copepods ranged within 10(3)-10(6), and showed higher dissolved concentration as the bioconcentration factor was lower. A substantial abundance, but with less copepod diversity was recorded in the seawater around the hydrothermal vent area. Temora turbinata was the species of opportunity under the hydrothermal vent influence. Copyright © 2013. Published by Elsevier Ltd.

  13. The impact of polystyrene microplastics on feeding, function and fecundity in the marine copepod Calanus helgolandicus.

    Science.gov (United States)

    Cole, Matthew; Lindeque, Pennie; Fileman, Elaine; Halsband, Claudia; Galloway, Tamara S

    2015-01-20

    Microscopic plastic debris, termed “microplastics”, are of increasing environmental concern. Recent studies have demonstrated that a range of zooplankton, including copepods, can ingest microplastics. Copepods are a globally abundant class of zooplankton that form a key trophic link between primary producers and higher trophic marine organisms. Here we demonstrate that ingestion of microplastics can significantly alter the feeding capacity of the pelagic copepod Calanus helgolandicus. Exposed to 20 μm polystyrene beads (75 microplastics mL(–1)) and cultured algae ([250 μg C L(–1)) for 24 h, C. helgolandicus ingested 11% fewer algal cells (P = 0.33) and 40% less carbon biomass (P microplastics significantly decreased reproductive output, but there were no significant differences in egg production rates, respiration or survival. We constructed a conceptual energetic (carbon) budget showing that microplastic-exposed copepods suffer energetic depletion over time. We conclude that microplastics impede feeding in copepods, which over time could lead to sustained reductions in ingested carbon biomass.

  14. 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.

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

    Directory of Open Access Journals (Sweden)

    Joy N Smith

    Full Text Available 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. Effects of rotifers, copepods and chironomid larvae on microbial communities in peatlands.

    Science.gov (United States)

    Mieczan, Tomasz; Niedźwiecki, Michał; Tarkowska-Kukuryk, Monika

    2015-10-01

    Interactions between the microbial loop and the classical grazing food chain are essential to ecosystem ecology. The goal of the present study was to examine the impact of chironomid larvae, rotifers and copepods on the major components of the microbial food web (algae, bacteria, heterotrophic flagellates, testate amoebae and ciliates) in peatlands. Two enclosure experiments were carried out in a Sphagnum peatland. In the experiments we manipulated rotifers, copepods and macroinvertebrates, i.e. chironomid larvae (Psectrocladius sordidellus gr). During the experiments variation was observed in the abundance of potential predators. The beginning of the first experiment was distinguished by dominance of rotifers, but five days later copepods were dominant. In the second experiment copepods dominated. The results of this study are the first to suggest a substantial impact of chironomid larvae, rotifers and copepods on microorganism communities in peatland ecosystems. The impact is reflected by both a decrease in the abundance and biomass of testate amoebae and ciliates and a transformation of the size structure of bacteria. Heterotrophic flagellates (HNF) were not controlled by metazoans, but rather by testate amoebae and ciliates, as HNF were more abundant in the control treatment. Copyright © 2015 Elsevier GmbH. All rights reserved.

  17. 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.

  18. 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...

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

    Digital Repository Service at National Institute of Oceanography (India)

    Jagadeesan, L.; Jyothibabu, R.

    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...

  20. An analysis of how to improve production of copepods as live feed from tropical Taiwanese outdoor aquaculture ponds

    DEFF Research Database (Denmark)

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

    2017-01-01

    The motivation for this study was to analyse the productivity of Taiwanese aquaculture ponds while providing recommendations for a more effective copepod harvesting. Hence, variations in copepod species composition, biomass and productivity were investigated during four separate 3 weeks of intens...

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

    DEFF Research Database (Denmark)

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

    2016-01-01

    % 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 mu m) than droplets in the physically...

  2. 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

    Copepods are well known to be the optimal live feed for most species of marine fish larvae. Still copepods are rarely used in marine hatcheries worldwide. Lack of efficient production techniques are among the reasons for this. Consequently, Artemia and rotifers are utilized in commercial settings...

  3. 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...... and controlled by temperature during winter. The seasonal signal in fecundity and population biomass is much weaker than in the co-occurring free-spawning calanoid genera, where fecundity and population biomass undergo dramatic seasonal variation....

  4. 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

    The present study describes three outdoor ponds for mass rearing of copepods in tropical southern Taiwan. The systems are designed for culturing and harvesting of copepods, which are used as live feed in the production of groupers in the region. However, the production of the most common copepod...... species Pseudodiaptomus annandalei (Sewell 1919) has, according to the pond managers, decreased over the last 10 years for no apparent reasons. In order to understand the limitations in terms of production, the present study was carried out. A one month comprehensive monitoring of abiotic factors......, inorganic nutrients, phytoplankton and zooplankton as well as the spatial patchiness of zooplankton in the ponds was conducted. The ultimate aims were to: (I) obtain a better understanding of the variability and the interactions among the trophic levels in the pelagic; (II) obtain a sampling practice...

  5. Horizontal transmission of Parathelohania anophelis to the copepod, Microcyclops varicans, and the mosquito, Anopheles quadrimaculatus.

    Science.gov (United States)

    Avery, S W; Undeen, A H

    1990-07-01

    The copepod Microcyclops varicans was infected with Parathelohania anophelis by unincleate meiospores from a field-collected fourth instar Anopheles quadrimaculatus larva. Large numbers of unincleate, pyriform spores developed in the copepod. These spores were fed to early instar A. quadrimaculatus larvae, infecting both males and females, resulting in the production of cylindrical, binucleate spores in the adult. These spores were responsible for vertical transmission, through the eggs, to the larvae. The original spore type collected from the field was found in the male progeny from the infected females. Another P. anophelis-infected mosquito colony was established by feeding spores from a single, field-collected, infected copepod to A. quadrimaculatus larvae. The microsporidium was continuously maintained by vertical transmission in newly established infected colonies.

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

    Science.gov (United States)

    Garzke, Jessica; 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.

  7. 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.

  8. 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, predator...... treatment, but increased towards the end of the experiment. The proportion of fertilized females was similar in both treatments, but constantly fell behind model predictions using a random mating model. Our results highlight the importance of non-consumptive effects of predators on copepod reproduction...

  9. 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, larg...... fertilize females for only about eight days after they mature. The strong size- and age-dependent fertility observed in this species is conducive to the development of sexual selection via mate choice for young and large partners, as has been shown in one other copepod species...

  10. Dissolved Compounds Excreted by Copepods Reshape the Active Marine Bacterioplankton Community Composition

    Directory of Open Access Journals (Sweden)

    Valentina P. Valdés

    2017-11-01

    Full Text Available Copepods are important suppliers of bioreactive compounds for marine bacteria through fecal pellet production, sloppy feeding, and the excretion of dissolved compounds. However, the interaction between copepods and bacteria in the marine environment is poorly understood. We determined the nitrogen and phosphorus compounds excreted by copepods fed with two natural size-fractionated diets (<20- and 20–150-μm in the upwelling zone of central/southern Chile in late summer and spring. We then assessed the biogeochemical response of the bacterial community and its structure, in terms of total and active cells, to enrichment by copepod-excreted dissolved compounds. Results revealed that copepods actively excreted nitrogen and phosphorus compounds, mainly in the form of ammonium and dissolved organic phosphorus (DOP, reaching excretion rates of 2.6 and 0.05 μmol L−1h−1, respectively. In both periods, the maximum excretion rates were associated with the 20–150-μm size fraction, but particularly during spring, when a higher organic matter quality was observed in excretion products compared to late summer. There were higher excretion rates of dissolved free amino acids (DFAAs from copepods fed with the <20-μm size fraction, mainly histidine (HIS in late summer and glutamic acid (GLU in spring. A shift in the composition of the active bacterial community was observed between periods and treatments, which was associated with the response of the common seawater surface phyla Proteobacteria and Bacteroidetes. The specific bacterial activity (16S rRNA:rDNA suggested a different response to the two size-fractionated diets. In late summer, Betaproteobacteria and Bacteroidetes were stimulated by the treatment enriched with excretion products derived from the 20–150-μm and <20-μm size fractions, respectively. In spring, Alphaproteobacteria were active in the treatment enriched with the excretion products of copepods fed with the <20-μm size

  11. In situ feeding rates of plantonic copepods: A comparison of four methods

    DEFF Research Database (Denmark)

    Kiørboe, Thomas; Møhlenberg, Flemming; Riisgård, Hans Ulrik

    1985-01-01

    During a spring phytoplankton bloom in the Kattegat and Skagerrak area (Denmark) comparisons were made of the natural feeding rates obtained by four different methods of seven species of planktonic copepods. Measurements of gut contents (gut fluorescence) of freshly caught copepods were converted...... into estimates of in situ algal grazing rates by means of independently estimated gut turnover times, and were compared with chlorophyll and particle-volume grazing rates of animals sampled simultaneously and incubated in water from the collection depth. In addition, egg-production rates of adult females were...

  12. Multiple vs. single phytoplankton species alter stoichiometry of trophic interaction with zooplankton.

    Science.gov (United States)

    Plum, Christoph; Hüsener, Matthias; Hillebrand, Helmut

    2015-11-01

    Despite the progress made in explaining trophic interactions through the stoichiometric interplay between consumers and resources, it remains unclear how the number of species in a trophic group influences the effects of elemental imbalances in food webs. Therefore, we conducted a laboratory experiment to test the hypothesis that multispecies producer assemblages alter the nutrient dynamics in a pelagic community. Four algal species were reared in mono- and polycultures under a 2 x 2 factorial combination of light and nutrient supply, thereby contrasting the stoichiometry of trophic interactions involving single vs. multiple producer species. After 9 d, these cultures were fed to the calanoid copepod Acartia tonsa, and we monitored biomass, resource use, and C:N:P stoichiometry in both phyto- and zooplankton. According to our expectations, light and N supply resulted in gradients of phytoplankton biomass and nutrient composition (C:N:P). Significant net diversity effects for algal biomass and C:N:P ratios reflected the greater responsiveness of the phytoplankton polyculture to altered resource supply compared to monocultures. These alterations of elemental ratios were common, and were partly triggered by changes in species frequency in the mixtures and partly by diversity-related changes in resource use. Copepod individual biomass increased under high light (HL) and N-reduced (-N) conditions, when food was high in C:N but low in C:P and N:P, whereas copepod growth was obviously P limited, and copepod stoichiometry was not affected by phytoplankton elemental composition. Correspondingly, copepod individual biomass reflected significant net diversity effects: compared to expectations- derived from monocultures, copepod individuals feeding on algal polycultures remained smaller than predicted under HL and N-sufficient (+N) conditions but grew larger than predicted under HL, -N and low light +N conditions. In conclusion, multiple producer species altered the

  13. Quantifying copepod sensing and swimming in unsteady flow fields using time-resolved tomographic PIV + 3D PTV

    Science.gov (United States)

    Adhikari, Deepak; Longmire, Ellen

    2013-11-01

    Copepods respond to hydrodynamic disturbances by executing an escape response jump (Buskey et al. 2002; Fields and Yen 1996; Kiørboe et al. 1999; Strickler and Bal 1973). 3D PTV and tomographic PIV are combined to track the motion of the copepods and the surrounding fluid velocity field respectively, to provide quantitative measure on their sensing and swimming behavior. The measurements are time-resolved to obtain the entire trajectories of copepods. Fluid velocity and velocity gradients are estimated at the location of the copepod by applying a Taylor-series least-square method to the surrounding PIV grid points. Copepod sensing and swimming are analyzed upstream and downstream of a wall-mounted cylinder in cross-flow at Re ~ 930. At the upstream location, when copepods approach the cylinder, they respond by rapidly accelerating (or jumping) away from it. Their jump location suggests that they sense and respond to a range of flow velocity gradients. Preliminary results indicate that copepods in the cylinder wake do not jump frequently as compared to upstream. The velocity gradient thresholds for sensing and range of maximum velocities during jumping will be presented and discussed. Supported by NSF-IDBR grant #0852875.

  14. 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.

  15. Seasonal variability of meiofauna, especially harpacticoid copepods, in Posidonia oceanica macrophytodetritus accumulations

    Science.gov (United States)

    Mascart, Thibaud; Lepoint, Gilles; Deschoemaeker, Silke; Binard, Marc; Remy, François; De Troch, Marleen

    2015-01-01

    The overall aim of this study was (1) to assess the diversity and density of meiofauna taxa, especially harpacticoid copepod species, present within accumulated seagrass macrophytodetritus on unvegetated sand patches and (2) to elucidate the community structure of detritus-associated harpacticoid copepods in relation to natural temporal variability of physico-chemical characteristics of accumulations. This was investigated in a Posidonia oceanica (L.) Delile seagrass ecosystem in the northwest Mediterranean Sea (Bay of Calvi, Corsica, 42°35‧N, 8°43‧E) using a triplicate macrophytodetritus core field sampling in two contrasting sites over the four seasons of 2011. Meiofauna higher taxa consisted of 50% Copepoda, of which 87% belonged to the Harpacticoida order. Nematoda was the second most abundant taxa. The copepod community displayed a wide variety of morphologically similar and ecologically different species (i.e. mesopsammic, phytal, phytal-swimmers, planktonic and parasitic). The harpacticoid copepod community followed a strong seasonal pattern with highest abundances and species diversity in May-August, revealing a link with the leaf litter epiphyte primary production cycle. Aside from the important role in sheltering, housing and feeding potential of macrophytodetritus, a harpacticoid community BEST analysis demonstrated a positive correlation with habitat complexity and a negative correlation with water movements and P. oceanica leaf litter accumulation.

  16. Two new species of Harpacticoid Copepods (Copepoda, Harpacticoida, Canthocamptidae) from Montenegro (Balkan Peninsula)

    NARCIS (Netherlands)

    Karanovic, Tomislav

    1997-01-01

    In the present paper two new species of harpacticoid copepods (family Canthocamptidae) are described from several subterranean localities in Montenegro, Crmnica region. Moraria jana n.sp. is most similar to M. catalana Chappuis & Kiefer, 1952. It is also alike M. brevipes (Sars, 1863). Elaphoidella

  17. 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.

  18. 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

    -analysis revealed that marine copepods in general have much lower - by an order of magnitude - levels of carotenoids than freshwater species, while levels of MAAs are similar between the two habitats. We conclude that allocation to different fitness components to some extent is plastic although egg quality...

  19. 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

  20. C and N gross efficiencies of copepod egg production studies using a dynamic energy budget model.

    NARCIS (Netherlands)

    Kuijper, L.D.J.; Anderson, T.R.; Kooijman, S.A.L.M.

    2004-01-01

    Simple stoichiometric models based on the principle that limiting elements are used with high efficiency have been unable to capture the apparently constant and low nitrogen gross growth efficiency that characterizes egg production in marine copepods. A new model of egg production is presented based

  1. C and N gross efficiencies of copepod egg production studies using a dynamic energy budget model

    NARCIS (Netherlands)

    Kuijper, L.D.J.; Anderson, T.; Kooijman, S.A.L.M.

    2003-01-01

    Simple stoichiometric models based on the principle that limiting elements are used with high efficiency have been unable to capture the apparently constant and low nitrogen gross growth efficiency that characterizes egg production in marine copepods. A new model of egg production is presented based

  2. 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

  3. 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-web...

  4. Effects of environmental and water quality parameters on the functioning of copepod assemblages in tropical estuaries

    Science.gov (United States)

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

    2017-07-01

    We examined changes in the functioning of copepod assemblages with increasing pollution in estuaries, using sampling standardization of the salinity range to enable comparisons. Copepod assemblages were analyzed in four southeast Brazilian estuaries with different water quality levels and hydrodynamic characteristics over two years. We obtained mesozooplankton samples together with environmental and water quality parameters in the estuaries, every two months under predetermined salinities ranging from 15 to 25. The values of parameters, except species size, associated with the functioning of the copepod assemblages (biomass, productivity, and turnover rate) did not differ among estuaries. However, in the more polluted estuaries, the biomass and productivity of copepod assemblages of mesozooplankton were negatively correlated with concentration of pollution indicator parameters. Conversely, in the less polluted estuaries some degree of enrichment still seems to increase the system biomass and productivity, as these parameters were inversely related to indicators of improved water quality. The pollution level of estuaries distorted the relationship between temperature and the efficiency of converting energy to organic matter. In the less polluted estuaries, the relationship between turnover rate and temperature was over 70%, while in the most polluted estuaries, this relationship was only approximately 50%. Our results demonstrated that the functioning of assemblages in the estuaries was affected differently by increasing pollution depending on the water quality level of the system. Thus, investigating the functioning of assemblages can be a useful tool for the analysis of estuarine conditions.

  5. 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.

    Observations were made on the copepod species association and succession at six stations in the Mandovi-Zuari estuarine system of Goa, India. A total of 55 species belonging to 25 genera and 18 families were encountered in the surface collections...

  6. PRELIMINARY STUDY ON POPULATION DYNAMIC OF HARPACTICOID COPEPOD Euterpina acutifrons IN CULTURE CONDITION

    Directory of Open Access Journals (Sweden)

    Philip Teguh Imanto

    2007-12-01

    Full Text Available The most important factor to high mortality rate in larval rearing is feeding success in early larval stage related to kind and size of natural live food. Copepod basically is the main source of natural food in the open ocean having some advantages such as smaller size of nauplii, attractive movement and high nutritional value. Observation on population dynamic of harpacticoid copepod Euterpina acutifrons was carried out using 5-L plastic bucket with initial density 100 ind./L. Green algae Nannochloropsis sp. was added to culture media at density of 50,000 cells/mL as a basic feed and additional feeds given were wheat flour (group A and chicken liver (group B at a rate of 50 mg/bucket. The result showed that there was no difference on population pattern in both groups where the incubation time took eight days to hatch, from nauplii to the copepodite stage was three days and from copepodite to adult copepod took five-to-six days. The differences came up from population number: in group (A the highest number of copepod-bearing-egg was only 133 ind., nauplii production up to 62,833 ind. and number of copepodites was 22,333 ind. lower compared to group (B with the highest copepod-egg was 308 ind., nauplii was 113,333 ind. and copepodite was 51,167 ind. The conclusion pointed out that the kind of food did not influence population pattern (quality but gave effect to population growth.

  7. 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.

    related to the annual cycle of salinity. Based on abundance during different months, the copepod species of the Mandovi and Zuari estuaries could be classified into three categories. (i) Species which were recorded the year round. This cat- egory...

  8. Relationships between copepod community structure, rainfall regimes, and hydrological variables in a tropical mangrove estuary (Amazon coast, Brazil)

    National Research Council Canada - National Science Library

    Magalhães, André; Pereira, Luci Cajueiro Carneiro; da Costa, Rauquírio Marinho

    2015-01-01

    The influence of rainfall and hydrological variables on the abundance and diversity of the copepod community was investigated on a monthly basis over an annual cycle in the Taperaçu mangrove estuary...

  9. 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.

  10. Metabarcoding and metabolome analyses of copepod grazing reveal feeding preference and linkage to metabolite classes in dynamic microbial plankton communities

    OpenAIRE

    Ray, Jessica L.; Althammer, Julia; Skaar, Katrine S; Simonelli, Paolo; Larsen, Aud; Stoecker, Diane; Sazhin, Andrey; Umer Z. Ijaz; Quince, Christopher; Nejstgaard, Jens C.; Frischer, Marc; Pohnert, Georg; Troedsson, Christofer

    2016-01-01

    In order to characterize copepod feeding in relation to microbial plankton community dynamics, we combined metabarcoding and metabolome analyses during a 22-day seawater mesocosm experiment. Nutrient amendment of mesocosms promoted the development of haptophyte (Phaeocystis pouchetii)- and diatom (Skeletonema marinoi)-dominated plankton communities in mesocosms, in which Calanus sp. copepods were incubated for 24 h in flow-through chambers to allow access to prey particles (

  11. The true nature of the enigmatic copepod genus Limnoncaea from plankton in Japan and the importance of parasito-planktology

    OpenAIRE

    大塚, 攻; 長澤, 和也; ,

    2004-01-01

    The history of an enigmatic copepod genus Limnoncaea Kokubo, 1914 is reviewed. Copepods of this genus had been recorded from plankton in many fresh/brackish lakes and ponds of Japan. It is recently concluded that Limnoncaea is relegated to a junior synonym of Ergasilus Nordmann, 1832, the species of which are mainly parasitic on fish. Here we explain how lack of interchange between the fields of planktology and parasitology prevented an earlier appreciation of this fact. Recently, postmated a...

  12. Sensitivity of the marine benthic copepod Tisbe biminiensis (copepoda, harpacticoida) to potassium dichromate and sediment particle size

    OpenAIRE

    Cristiane M. V. Araújo-Castro; Souza-Santos, Lília P.; Torreiro,Anny Gabrielle A .G.; Garcia, Karina S.

    2009-01-01

    For the future use of the marine benthic copepod Tisbe biminiensis in solid-phase sediment toxicological bioassays, the present study investigated the effect of muddy sediment from the Maracaípe estuary (northeastern Brazil), sediment particle size and the reference toxicant potassium dichromate on the species. Muddy sediment from Maracaípe can be used as control sediment, since it does not interfere in the copepod life-cycle and has metal contamination levels that are unlikely to produce any...

  13. 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.

  14. Assessment of storage lipid accumulation patterns in eucalanoid copepods from the eastern tropical Pacific Ocean

    Science.gov (United States)

    Cass, Christine J.; Daly, Kendra L.; Wakeham, Stuart G.

    2014-11-01

    Members of the copepod family Eucalanidae are widely distributed throughout the world's oceans and have been noted for their accumulation of storage lipids in high- and low-latitude environments. However, little is known about the lipid composition of eucalanoid copepods in low-latitude environments. The purpose of this study was to examine fatty acid and alcohol profiles in the storage lipids (wax esters and triacylglycerols) of Eucalanus inermis, Rhincalanus rostrifrons, R. nasutus, Pareucalanus attenuatus, and Subeucalanus subtenuis, collected primarily in the eastern tropical north Pacific near the Tehuantepec Bowl and Costa Rica Dome regions, noted for its oxygen minimum zone, during fall 2007 and winter 2008/2009. Adult copepods and particulate material were collected in the upper 50 m and from 200 to 300 m in the upper oxycline. Lipid profiles of particulate matter were generated to help ascertain information on ecological strategies of these species and on differential accumulation of dietary and modified fatty acids in the wax ester and triacylglycerol storage lipid components of these copepods in relation to their vertical distributions around the oxygen minimum zone. Additional data on phospholipid fatty acid and sterol/fatty alcohol fractions were also generated to obtain a comprehensive lipid data set for each sample. Rhincalanus spp. accumulated relatively large amounts of storage lipids (31-80% of dry mass (DM)), while E. inermis had moderate amounts (2-9% DM), and P. attenuatus and S. subtenuis had low quantities of storage lipid (0-1% DM). E. inermis and S. subtenuis primarily accumulated triacylglycerols (>90% of storage lipids), while P. attenuatus and Rhincalanus spp. primarily accumulated wax esters (>84% of storage lipids). Based on previously generated molecular phylogenies of the Eucalanidae family, these results appear to support genetic predisposition as a major factor explaining why a given species accumulates primarily triacylglycerols

  15. Bioaccumulation of photoprotective compounds in copepods: environmental triggers and sources of intra-specific variability

    Science.gov (United States)

    Zagarese, H. E.; García, P.; Diéguez, M. D.; Ferraro, M. A.

    2012-12-01

    Ultraviolet radiation (UVR) and temperature are two globally important abiotic factors affecting freshwater ecosystems. Planktonic organisms have developed a battery of counteracting mechanisms to minimize the risk of being damaged by UVR, which respond to three basic principles: avoid, protect, repair. Copepods are among the most successful zooplankton groups. They are highly adaptable animals, capable of displaying flexible behaviors, physiologies, and life strategies. In particular, they are well equipped to cope with harmful UVR. Their arsenal includes vertical migration, accumulation of photoprotective compounds, and photorepair. The preference for a particular strategy is affected by a plethora of environmental (extrinsic) parameters, such as the existence of a depth refuge, the risk of visual predation, and temperature. Temperature modifies the environment (e.g. the lake thermal structure), and animal metabolism (e.g., swimming speed, bioaccumulation of photoprotective compounds). In addition, the relative weight of UVR-coping strategies is also influenced by the organism (intrinsic) characteristics (e.g., inter- and intra-specific variability). The UV absorbing compounds, mycosporine-like amino acids (MAAs), are widely distributed among freshwater copepods. Animals are unable to synthesize MAAs, and therefore depend on external sources for accumulating these compounds. Although copepods may acquire MAAs from their food, for the few centropagic species investigated so far, the main source of MAAs are microbial (most likely prokaryotic) organisms living in close association with the copepods. Boeckella gracilipes is a common centropagic copepod in Patagonian lakes. We suspected that its occurrence in different types of lakes, hydrologically unconnected, but within close geographical proximity, could have resulted in different microbial-copepod associations (i.e., different MAAs sources) that could translate into intra-specific differences in the accumulation

  16. 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

    We studied female fertilization status in North Sea summer populations and laboratory cultures of the marine copepod Temora longicornis and found fractions of fertilized females in both field and laboratory populations that were much smaller (... 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...

  17. Effects of four synthetic musks on the life cycle of the harpacticoid copepod Nitocra spinipes

    DEFF Research Database (Denmark)

    Breitholtz, M.; Wollenberger, Leah; Dinan, L.

    2003-01-01

    A full life-cycle (:! 26 days exposure) toxicity test with the harpacticoid copepod Nitocra spinipes was used to study the effects of one nitro musk (musk ketone) as well as three polycyclic musks (Tonalide(TM), Celestolide(TM) and Galaxolide(TM)). A subchronic individual life-table endpoint......, the larval development rate, was recorded after 7-8 days exposure of juveniles and was significantly decreased in copepods exposed to sublethal concentrations of musk ketone, Celestolide(TM) and Galaxolide(TM). However, none of the Tonalide(TM) concentrations had any effect on larval development. The lowest...... melanogaster B-II-cell line. This indicates that the decrease in larval development rate was due to pharmacological effects rather than steroid receptor-mediated endocrine disruption. A modified Euler-Lotka equation was used to calculate a population-level endpoint, the intrinsic rate of natural increase (r...

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

    DEFF Research Database (Denmark)

    Dinh, Khuong Van; Nielsen, Torkel Gissel

    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......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...

  19. 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

    ) 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......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...... 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....

  20. 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....

  1. Molecular evidence of the toxic effects of diatom diets on gene expression patterns in copepods.

    Directory of Open Access Journals (Sweden)

    Chiara Lauritano

    Full Text Available BACKGROUND: Diatoms are dominant photosynthetic organisms in the world's oceans and are considered essential in the transfer of energy through marine food chains. However, these unicellular plants at times produce secondary metabolites such as polyunsaturated aldehydes and other products deriving from the oxidation of fatty acids that are collectively termed oxylipins. These cytotoxic compounds are responsible for growth inhibition and teratogenic activity, potentially sabotaging future generations of grazers by inducing poor recruitment in marine organisms such as crustacean copepods. PRINCIPAL FINDINGS: Here we show that two days of feeding on a strong oxylipin-producing diatom (Skeletonema marinoi is sufficient to inhibit a series of genes involved in aldehyde detoxification, apoptosis, cytoskeleton structure and stress response in the copepod Calanus helgolandicus. Of the 18 transcripts analyzed by RT-qPCR at least 50% were strongly down-regulated (aldehyde dehydrogenase 9, 8 and 6, cellular apoptosis susceptibility and inhibitor of apoptosis IAP proteins, heat shock protein 40, alpha- and beta-tubulins compared to animals fed on a weak oxylipin-producing diet (Chaetoceros socialis which showed no changes in gene expression profiles. CONCLUSIONS: Our results provide molecular evidence of the toxic effects of strong oxylipin-producing diatoms on grazers, showing that primary defense systems that should be activated to protect copepods against toxic algae can be inhibited. On the other hand other classical detoxification genes (glutathione S-transferase, superoxide dismutase, catalase, cytochrome P450 were not affected possibly due to short exposure times. Given the importance of diatom blooms in nutrient-rich aquatic environments these results offer a plausible explanation for the inefficient use of a potentially valuable food resource, the spring diatom bloom, by some copepod species.

  2. 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....

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

    Science.gov (United States)

    Kiørboe, Thomas; Andersen, Anders; Langlois, Vincent J.; Jakobsen, Hans H.

    2010-01-01

    We describe the kinematics of escape jumps in three species of 0.3–3.0 mm-sized planktonic copepods. We find similar kinematics between species with periodically alternating power strokes and passive coasting and a resulting highly fluctuating escape velocity. By direct numerical simulations, we 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 velocities in other aquatic organisms. The relative duration of the pauses between power strokes was observed to increase with organism size. We demonstrate that this is an inherent property of swimming by alternating power strokes and pauses. We finally show that the Strouhal number is in the range of peak propulsion efficiency, again suggesting that copepods are optimally designed for rapid escape jumps. PMID:20462876

  4. Behaviour-dependent Predation Risk in Marine Planktonic Copepods: an Experimental and Modelling Approach

    Science.gov (United States)

    Almeda, R.; van Someren Gréve, H.; Kiørboe, T.

    2016-02-01

    Zooplankton exhibit different motile behaviors related to mating, feeding and swimming activities. These differences in motility may imply different levels of predation risk, which may partially determine the structure of pelagic communities. However, empirical evidence and models of the influence of zooplankton behavior on predation risk are still limited. In this study, we experimentally investigated predation mortality related to different motile behaviors in marine planktonic copepods. We conducted bottle incubation predation experiments to estimate predation risk associated with (i) mating- and gender differences in behavior and (ii) feeding/ swimming activity (ambush feeders vs feeding-current vs. cruising feeders). Low and high speed video-filming was used to determine prey motility behavior parameters such as speeds, durations and frequencies of sinking, swimming and jumping events, as well as escape responses of each prey type. We will present experimental results of predation on copepod with different motile behavior and propose a simple prey behavior-dependent encounter model to predict predation risk on planktonic copepods. Overall, our results demonstrate that motile behavior is a key factor affecting predation risk in zooplankton.

  5. 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.

  6. 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. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. Lethal and sublethal effects of the sediment-associated PCB Aroclor 1254 on a meiobenthic copepod

    Energy Technology Data Exchange (ETDEWEB)

    DiPinto, L.M.; Coull, B.C.; Chandler, G.T. (Univ. of South Carolina, Columbia, SC (United States). Dept. of Environmental Health Sciences, Marine Science Program, and Belle W. Baruch Inst. for Marine Biology and Coastal Research)

    1993-10-01

    Acute toxicity tests were performed on field-collected copepods (Microarthridion littorale) using the sediment-associated polychlorinated biphenyl (PCB) Aroclor 1254 (i.e., PCB concentrations in bulk sediments in the bound and/or unbound states). Three replicates of 50 adult copepods were exposed to five levels of PCB-contaminated sediments for 96 h and compared to untreated controls and solvent controls. LC50 concentrations were nearly twice as high for females as for males. To determine the effects of the PCB on reproductive output of the copepods, copulating pairs of Microarthridion littorale were allowed to reproduce in concentrations of Aroclor 1254-contaminated sediments below LC50 values. Two experimental trials with 10 and 15 replicates, each with one pair of Microarthridion littorale in copulus, were conducted for 12 d, the normal time needed for females to produce one set of nauplii and carry a second clutch of eggs. In both experiments, a significant decrease in number of nauplii was found with Aroclor contamination. Although NOECs were not determined, high concentrations of the sediment-associated Aroclor NOECs were required to affect mortality significantly, whereas lower levels impaired reproduction.

  8. 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

    In productive marine off-shore ecosystems, the flow of energy from zooplankton to large predators is channeled through a few species of short-lived, highly abundant schooling planktivorous fish. There are indications that these species respond to qualitative and phenological changes in the zoopla...... was the most important factor, followed by handling time limitation and prey energy content. These limitations became stronger with increasing fish length, showing that copepod size and energy content have a strong effect on the specific growth potential of these fish......In productive marine off-shore ecosystems, the flow of energy from zooplankton to large predators is channeled through a few species of short-lived, highly abundant schooling planktivorous fish. There are indications that these species respond to qualitative and phenological changes...... in the zooplankton. If so, the climate-induced alterations of the local copepod communities that we see in temperate and arctic regions may influence the energy flux in marine food chains. In order to investigate how different processes contribute to the relationship between copepod size and fish growth, we merged 2...

  9. Development and application of a sublethal toxicity test to PAH using marine harpacticoid copepods. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Fleeger, J.W.; Lotufo, G.R.

    1999-01-01

    This research project was designed to improve the understanding of the acute and sublethal effects of PAHs to benthic invertebrates. Sublethal bioassay protocols for benthic harpacticoid copepods were developed, and two species of harpacticoids were exposed to a range of concentrations of sediment-amended PAHs; the single compounds fluoranthene and phenanthrene as well as a complex mixture (diesel fuel). The harpacticoid copepods Schizopera knabeni and Nitocra lacustris were tested using several bioassay approaches. Reproductive assays, feeding assays and avoidance tests were conducted in addition to lethal tests for S. knabeni. Species-specific differences in sensitivity were detected. Early life history stages were much more sensitive than adults in one species but not in the other. Concentrations of PAH as low as 26 micrograms PAH decreased copepod offspring production, egg hatching success, and embryonic and early-stage development, demonstrating the high sensitivity of life history-related endpoints. In addition, grazing on microalgae was significantly impaired at concentrations as low as 20 micrograms/g PAH after short exposures (<30 h). Finally it was demonstrated that harpacticoids can actively avoid contamination.

  10. Copepod (Crustacea) emergence from soils from everglades marshes with different hydroperiods

    Science.gov (United States)

    Loftus, W.F.; Reid, J.W.

    2000-01-01

    During a severe drought period in the winter and spring of 1989, we made three collections of dried marsh soils from freshwater sloughs in Everglades National Park, Florida, at sites characterized by either long or intermediate annual periods of flooding (hydroperiod). After rehydrating the soils in aquaria, we documented the temporal patterns of copepod emergence over two-week periods. The species richness of copepods in the rehydrated soils was lower than in pre-drought samples from the same slough sites. Only six of the 16 species recorded from the Everglades emerged in the aquarium tests. The long hydroperiod site had a slightly different assemblage and higher numbers of most species than the intermediate-hydroperiod sites. More individuals and species emerged from the early dry-season samples compared with samples taken later in the dry season. The harpacticoid, Cletocamptus deitersi, and the cyclopoid, Microcyclops rubellus, were abundant at most sites. The cyclopoids - Ectocyclops phaleratus, Homocyclops ater, and Paracyclops chiltoni - are new records for the Everglades. We infer that 1) only a subset of Everglades copepod species can survive drought by resting in soils; and that 2) survival ability over time differs by species.

  11. Copepods enhance nutritional status, growth and development in Atlantic cod (Gadus morhua L.) larvae - can we identify the underlying factors?

    Science.gov (United States)

    Karlsen, Ørjan; van der Meeren, Terje; Rønnestad, Ivar; Mangor-Jensen, Anders; Galloway, Trina F; Kjørsvik, Elin; Hamre, Kristin

    2015-01-01

    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.

  12. The effects of a parasitic copepod on the recent larval growth of a fish inhabiting rocky coasts.

    Science.gov (United States)

    Palacios-Fuentes, Pamela; Landaeta, Mauricio F; Muñoz, Gabriela; Plaza, Guido; Ojeda, F Patricio

    2012-10-01

    Parasites can infect larval, juvenile or adult marine fishes; however, the effects of parasites on the growth and condition of fish larvae have seldom been investigated. This study analysed the effects of a parasitic copepod on the larval growth of the Chilean triplefin Helcogrammoides chilensis (Tripterygiidae) based on the microstructure of the sagittal otoliths. Fish larvae were collected during the austral spring of 2010 off central Chile. Their body length ranged from 5.1 to 16.6 mm (2 to 57 days old). They were parasitised by a penellid larval copepod that was always externally attached to the ventral side of the fish's gut. The prevalence of the copepod ranged from 2.7% to 20.8%, with one to four parasites per fish larva. Relationships between otolith size (radius, perimeter) and larval size were equal for parasitised and unparasitised fish larvae (P > 0.05). Larval growth was also similar for unparasitised (0.21 mm/day) and parasitised fish larvae (0.19 mm/day) (P > 0.05). However, a comparison of same-aged larvae showed that the larvae with copepods were smaller in both length and estimated body volume than the larvae without copepods. The Recent Otolith Growth Index, indicated that larval H. chilensis with copepods showed a reduction in recent growth and condition compared with those without evidence of copepods (P fish. The infestation of pennellids on coastal fish larvae may therefore induce an increase in the pelagic larval duration and potentially affect the settlement rates of this intertidal fish.

  13. Estructura genética del copépodo Acartia lilljeborgii en la costa del estado de Yucatán, México

    Directory of Open Access Journals (Sweden)

    Jorge Tello-Cetina

    2013-11-01

    Full Text Available Se determinó la estructura genética poblacional y sus implicancias dentro de la cadena trófica del copépodo Acartia lilljeborgii en la costa de Yucatán, mediante el uso de isoenzimas y su posterior determinación por electroforesis. Nueve sistemas se expresaron con un máximo de 30 loci. El polimorfismo y heterocigosis de las poblaciones estudiadas, al ser comparados con otras especies de copépodos, resultaron ser bajos y de los cuatro loci que presentaron variación, solo los loci EST2 y PGM1 se expresaron en todos los sitios de muestreo. La PGM1 presentó el mayor valor de heterocigosis (0,4728 y la GPI1 fue la de menor valor (0,3200. Ningún sistema se apartó de la condición de equilibrio de Hardy-Weinberg. Los valores de FST estuvieron entre los valores de -0,0798 para PGM1 y de 0,5899 para FBP1. Las tres poblaciones de A. lilljeborgii analizadas en la costa de Yucatán, presentaron una baja variabilidad y diferenciación genética entre las poblaciones, como lo indican los valores de distancia genética de 0,0585 que fue el mayor para las poblaciones de Chelem y de Río Lagartos, lo que sugiere que estas poblaciones están parcialmente aisladas. Sin embargo, debido a que A. lilljeborgii produce huevos diapáusicos o de reposo, que pueden ser transportados fuera o dentro de éstos cuerpos de agua, es probable que esta condición mantenga las frecuencias alélicas y genotípicas similares o muy cercanas entre sí. Los resultados mostraron la existencia de flujo genético, dado a través de una dispersión pasiva de los huevos diapáusicos que produce esta especie.

  14. 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.

  15. Response of copepods to elevated pCO2 and environmental copper as co-stressors--a multigenerational study.

    Science.gov (United States)

    Fitzer, Susan C; Caldwell, Gary S; Clare, Anthony S; Upstill-Goddard, Robert C; Bentley, Matthew G

    2013-01-01

    We examined the impacts of ocean acidification and copper as co-stressors on the reproduction and population level responses of the benthic copepod Tisbe battagliai across two generations. Naupliar production, growth, and cuticle elemental composition were determined for four pH values: 8.06 (control); 7.95; 7.82; 7.67, with copper addition to concentrations equivalent to those in benthic pore waters. An additive synergistic effect was observed; the decline in naupliar production was greater with added copper at decreasing pH than for decreasing pH alone. Naupliar production modelled for the two generations revealed a negative synergistic impact between ocean acidification and environmentally relevant copper concentrations. Conversely, copper addition enhanced copepod growth, with larger copepods produced at each pH compared to the impact of pH alone. Copepod digests revealed significantly reduced cuticle concentrations of sulphur, phosphorus and calcium under decreasing pH; further, copper uptake increased to toxic levels that lead to reduced naupliar production. These data suggest that ocean acidification will enhance copper bioavailability, resulting in larger, but less fecund individuals that may have an overall detrimental outcome for copepod populations.

  16. Spatial patterns of littoral zooplankton assemblages along a salinity gradient in a brackish sea: A functional diversity perspective

    Science.gov (United States)

    Helenius, Laura K.; Leskinen, Elina; Lehtonen, Hannu; Nurminen, Leena

    2017-11-01

    The distribution patterns and diversity of littoral zooplankton are both key baseline information for understanding the functioning of coastal ecosystems, and for identifying the mechanisms by which the impacts of recently increased eutrophication are transferred through littoral food webs. In this study, zooplankton community structure and diversity along a shallow coastal area of the northern Baltic Sea were determined in terms of horizontal environmental gradients. Spatial heterogeneity of the zooplankton community was examined along the gradient. Altogether 31 sites in shallow sandy bays on the coast of southwest Finland were sampled in the summer periods of 2009 and 2010 for zooplankton and environmental variables (surface water temperature, salinity, turbidity, wave exposure, macrophyte coverage, chlorophyll a and nutrients). Zooplankton diversity was measured as both taxonomic as well as functional diversity, using trait-based classification of planktonic crustaceans. Salinity, and to a lesser extent turbidity and temperature, were found to be the main predictors of the spatial patterns and functional diversity of the zooplankton community. Occurrence of cyclopoid copepods, as well as abundances of the calanoid copepod genus Acartia and the rotifer genus Keratella were found to be key factors in differentiating sites along the gradient. As far as we know, this is the first extensive study of functional diversity in Baltic Sea coastal zooplankton communities.

  17. Inventory and comparison of abundance of parasitic copepods on fish hosts in the western Wadden Sea (North Sea) between 1968 and 2010

    NARCIS (Netherlands)

    Koch, W.; Boer, P.; Witte, J.IJ.; van der Veer, H.W.; Thieltges, D.W.

    2014-01-01

    A conspicuous part of the parasite fauna of marine fish are ectoparasites, which attach mainly to the fins or gills. The abundant copepods have received much interest due to their negative effects on hosts. However, for many localities the copepod fauna of fish is still poorly known, and we know

  18. 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

    was 0.45 and 1/3 of the food ingestion in female was assimilated into egg production; this algal PBR system can sustain a copepod culture which can provide a daily total egg production of 10 - 14 × 106 copepod eggs. The achievement of high cell density in the PBRs was close to the optimal cell density......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...

  19. Physical control of the distributions of a key Arctic copepod in the Northeast Chukchi Sea

    Science.gov (United States)

    Elliott, Stephen M.; Ashjian, Carin J.; Feng, Zhixuan; Jones, Benjamin; Chen, Changsheng; Zhang, Yu

    2017-10-01

    The Chukchi Sea is a highly advective regime dominated by a barotropically driven northward flow modulated by wind driven currents that reach the bottom boundary layer of this shallow environment. A general northward gradient of decreasing temperature and food concentration leads to geographically divergent copepod growth and development rates between north and south. The physics of this system establish the biological connection potential between specific regions. The copepod Calanus glacialis is a key grazer, predator, and food source in Arctic shelf seas. Its summer distribution and abundance have direct effects on much of the food web, from phytoplankton to migrating bowhead whales. In August 2012 and 2013, C. glacialis distributions were quantified over Hanna Shoal in the northeast Chukchi Sea. Here an individual-based model with Lagrangian tracking and copepod life stage development capabilities is used to advect and develop these distributions forward and backward in time to determine the source (production locations) and sink (potential overwintering locations) regions of the transient Hanna Shoal C. glacialis population. Hanna Shoal supplies diapause competent C. glacialis to both the Beaufort Slope and the Chukchi Cap, mainly receives juveniles from the broad slope between Hanna Shoal and Herald Valley and receives second year adults from as far south as the Anadyr Gulf and as near as the broad slope between Hanna Shoal and Herald Valley. The 2013 sink region was shifted west relative to the 2012 region and the 2013 adult source region was shifted north relative to the 2012 adult source region. These connection potentials were not sensitive to precise times and locations of release, but were quite sensitive to depth of release. These patterns demonstrate how interannual differences in the physical conditions well south of Hanna Shoal play a critical role in determining the abundance and distribution of a key food source over Hanna Shoal and in the

  20. 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

  1. To eat and not be eaten: Optimal foraging behaviour in suspension feeding copepods

    DEFF Research Database (Denmark)

    Kiørboe, Thomas; Jiang, Houshuo

    2013-01-01

    different hydrodynamic signals to predators and different predator encounter speeds but may also differ in their efficiency; the optimal behaviour is that which maximizes the net energy gain over the predation risk. Here, we show by means of flow visualization and simple hydrodynamic and optimization models...... that copepods with a diversity of feeding behaviours converge on optimal, size-independent specific clearance rates that are consistent with observed clearance rates of zooplankton, irrespective of feeding mode, species and size. We also predict magnitudes and size-scaling of swimming speeds that are consistent...

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

    Directory of Open Access Journals (Sweden)

    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

  3. 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

  4. The fluid physics of signal perception by mate-tracking copepods.

    Science.gov (United States)

    Yen, J; Weissburg, M J; Doall, M H

    1998-05-29

    Within laboratory-induced swarms of the marine copepod Temora longicornis, the male exhibits chemically mediated trail-following behaviour, concluding with fluid mechanical provocation of the mate-capture response. The location and structure of the invisible trail were determined by examining the specific behaviour of the female copepods creating the signal, the response of the male to her signal, and the fluid physics of signal persistence. Using the distance of the mate-tracking male from the ageing trail of the female, we estimated that the molecular diffusion coefficient of the putative pheromonal stimulant was 2.7 x 10(-5) cm2 s-1, or 1000 times slower than the diffusion of momentum. Estimates of signal strength levels, using calculations of diffusive properties of odour trails and attenuation rates of fluid mechanical signals, were compared to the physiological and behavioural threshold detection levels. Males find trails because of strong across-plume chemical gradients; males sometimes go the wrong way because of weak along-plume gradients; males lose the trail when the female hops because of signal dilution; and mate-capture behaviour is elicited by suprathreshold flow signals. The male is stimulated by the female odour to accelerate along the trail to catch up with her, and the boundary layer separating the signal from the chemosensitive receptors along the copepod antennule thins. Diffusion times, and hence reaction times, shorten and behavioural orientation responses can proceed more quickly. While 'perceptive' distance to the odour signal in the trail or the fluid mechanical signal from the female remains within 1-2 body lengths (trails and vortex tubes (isotropic, millimetre-centimetre scale, 10:1 aspect ratio, 10s persistence), indicates that these trails are constrained by the same physical forces that influence water motion in a low Reynolds number fluid regime, where viscosity limits forces to the molecular scale. The exploratory reaches of mating

  5. Eight new species of ascidicolous copepods from the eastern coast of Korea (Crustacea, Copepoda, Cyclopoida)

    Science.gov (United States)

    Kim, Il-Hoi; Moon, Seong Yong

    2011-03-01

    Eight new species of copepods associated with shallow-water ascidians are described from the eastern coast of Korea. They are Ascidicola secundus n. sp. from a Pyura sp., Enteropsis nudus n. sp. from Pyura sacciformis (Drasche), Mycophilus capillatus n. sp. from a compound ascidian, Bonnierilla yangpoensis n. sp. from Phallusia cf. nigra Savigny, Janstockia truncata n. sp. from Chelyosoma siboja Oka, Pholeterides pilosa n. sp. from a compound ascidian, Pachypygus spinosus n. sp. from a solitary ascidian, and Paranotodelphys unguifer n. sp. from Ascidia samea Oka.

  6. Copepod swimming behavior, respiration, and expression of stress-related genes in response to high stocking densities

    DEFF Research Database (Denmark)

    Nilsson, Birgitte; Jakobsen, Hans H.; Stief, Peter

    2017-01-01

    Using copepod nauplii as live feed in aquaculture hatcheries could solve high mortality rates of first-feeding fish larvae due to malnutrition. However, implementing the use of copepod nauplii on an intensive production scale requires a stable production at preferably high densities, which......,000 ind. L−1. Three biological/physiological end-points were studied: swimming behavior, respiration rate and expression level of stress-related genes. None of the elevated densities caused any significant change in swimming behavior, respiration rate or gene expression level. This study suggests...

  7. Copepod community along the Mediterranean coast of Morocco (Southwestern Alboran Sea during spring

    Directory of Open Access Journals (Sweden)

    A. BERRAHO

    2016-09-01

    Full Text Available Copepod community along the Mediterranean Moroccan coast was investigated, for the first time, during April 2013. Total abundance varied from 53 to 4557 ind. m-3 and high values were found in coastal waters. Oithona nana and Paracalanus parvus dominated in the entire area and species diversity was decreasing from the West to the East. Hierarchical clustering revealed three groups of stations, depending on their geographic position (western, central and eastern areas. Indicator species analysis pointed out that Clausocalanus furcatus and Gaetanus sp. were significantly associated with Group I, Clausocalanus sp., Centropages sp. and Centropages chierchiae with Group II, whereas Temora longicornis was significantly associated with Group III. Detrended Correspondence Analysis based on the species abundance and environmental variables (temperature, salinity, chlorophyll-a, highlighted a more or less similar setting of stations which was related to salinity and temperature. The presence of three anticyclonic gyres at the northern part of the study area is suggested as the major factor acting on the variability of copepod community along the Mediterranean Moroccan coast.

  8. Parental effects on the larval performance of a tapeworm in its copepod first host.

    Science.gov (United States)

    Benesh, D P

    2013-08-01

    Parents can influence the phenotype of their offspring through various mechanisms, besides the direct effect of heredity. Such parental effects are little explored in parasitic organisms, perhaps because in many parasites, per capita investment into offspring is low. I investigated whether parental identity, beyond direct genetic effects, could explain variation in the performance of the tapeworm Schistocephalus solidus in its first intermediate host, a copepod. I first determined that two breeding worms could be separated from one another after ~48 h of in vitro incubation and that the isolated worms continued producing outcrossed eggs, that is, rates self-fertilization did not increase after separation. Thus, from a breeding pair, two sets of genetically comparable eggs can be collected that have unambiguous parental identities. In an infection experiment, I found that the development of larval worms tended to vary between the two parental worms within breeding pairs, but infection success and growth rate in copepods did not. Accounting for this parental effect decreased the estimated heritability for development by nearly half. These results suggest that larval performance is not simply a function of a worm's genotype; who mothered or fathered an offspring can also affect offspring fitness, contradicting the perhaps naïve idea that parasites simply produce large quantities of uniformly low-quality offspring. © 2013 The Author. Journal of Evolutionary Biology © 2013 European Society For Evolutionary Biology.

  9. 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.

  10. 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 mi...

  11. 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 f...

  12. 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...

  13. 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.

  14. 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

    The retreat of sea ice in the Arctic under global warming is predicted to intensify oil exploitation and shipping activities in this region, posing the risk of oil contamination. Knowledge on how Arctic secondary producers deal with the combined effects of global warming, particularly the extreme...... and grazing rate in both species and this pattern was independent of temperatures. Notably, exposure to high pyrene resulted in than 70% of mortality in C. finmarchicus that was two times higher than the mortality observed for C. glacialis. These results suggest that extreme temperature under global warming...... temperature and oil exposure is limited. To address this, we exposed females of two copepods species Calanus glacialis and C. finmarchicus to pyrene at three temperatures: 2, 6 and 10°C. Both species co-exist in the Disko Bay, Greenland, but only C. glacialis is a true Arctic specialist while C. finmarchicus...

  15. Blind dating - mate finding in planktonic copepods. II. The pheromone cloud of Pseudocalanus elongatus

    DEFF Research Database (Denmark)

    Kiørboe, Thomas; Bagøien, E.; Thygesen, Uffe Høgsbro

    2005-01-01

    Receptive females of Pseudocalanus elongatus, like many other planktonic copepods, produce pheromones to signal their presence and position to males, and thus enhance the rate of mate encounter. By means of 3D video recordings we describe how a characteristic behaviour is elicited in males...... that encounter the pheromone signal of a female. For several minutes the male speeds around the female along zigzagged and looped swimming trails. Every 10 to 20 s he approaches the female, slows down, and makes physical contact with her. Between visits, the male makes long excursions that may take him up to 15...... to move a little. Due to this small-scale dance of the female, pheromones are constantly being spread in different directions and from constantly shifting positions. Based on male and female behaviour and simple advection–diffusion models, we characterise the pheromone plume surrounding the female...

  16. Notes on the Egg Bearing Cyclopoid Copepod, Oithona similis Claus, 1866 of the Arabian Sea

    Directory of Open Access Journals (Sweden)

    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.

  17. Epizoic and ectoparasitic protozoans from planktonic copepods of the southwest and southeast coasts of India with the description of a new species

    Digital Repository Service at National Institute of Oceanography (India)

    Santhakumari, V.

    The epizoic and the ectoparasitic protozoans were studied from the planktonic copepods of the southwest and southeast coasts of India. The species of protozoans viz. Trochilioides trivialis Fenchel, Zoothamnium adamsi Stokes; Ephelota gemmipara...

  18. 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.

    structure of copepods in the tropical monsoonal estuarine system.The ecological scenario in the Cochin estuary revealed that irrespective of the season, higher zooplankton abundance occurred in the mesohaline zone (MSZ; salinity 5–18) of the estuary, despite...

  19. 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

    2017-01-01

    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...... predicts the viability of a spectrum of large-copepod strategies from income breeders with a adult size ~100 μgC reproducing once per year through capital breeders with an adult size > 1000 ugC with a multiple-year generation length. This spectrum corresponds closely to the observed life histories...

  20. Control of Diapause in Calanid Copepods: Identification of Regulatory Pathways using In Silico Data Mining

    Science.gov (United States)

    Lenz, P. H.; Roncalli, V.; Hopcroft, R. R.; Christie, A. E.

    2016-02-01

    As water temperatures and seasonal cycles change with global warming, questions are being raised on how these factors might affect the life cycles of copepods in the family Calanidae. These species depend on the completion of a seasonal diapause for the annual recruitment of the spring population. Diapause is a developmental program that includes induction, preparation, initiation, maintenance and termination. A lipid hypothesis has been proposed to explain the regulation of diapause in Calanus finmarchicus. While lipids may be critical for the diapause program, lipid metabolism is typically under neuroendocrine control. In insects, there is an extensive literature showing that juvenile hormone, ecdysteroids, and many neuropeptides are involved in the regulation of diapause. In particular, insulin signaling has been proposed as a key component in the diapause phenotype in a wide variety of insects, and through the actions of the transcription factor FOXO, many features of diapause can be linked to the insulin pathway, e.g., fat accumulation and enhancement of stress tolerance. Using the insects as models, we identified transcripts and predicted the protein components of the insulin/FOXO pathway (e.g., insulin-like peptide precursors, insulin receptors, juvenile hormone acid O-methyltransferase and FOXO), as well as a wide variety of neuropeptides (e.g., members of the diapause hormone family) and other proteins (e.g., those putatively involved in biological timing such as circadian and seasonal rhythmicity) that might be involved in the regulation of lipid metabolism and diapause in the calanid copepods C. finmarchicus and Neocalanus flemingeri. Our goal is to use the identified transcripts to start to understand the physiological processes underlying diapause in these calanids.

  1. Role of essential lipids in copepod nutrition: no evidence for trophic upgrading of food quality by a marine ciliate

    DEFF Research Database (Denmark)

    Klein Breteler, W.; Koski, Marja; Rampen, S.

    2004-01-01

    copepod species consumed S. sulcatum at significant rates, but after 3 d, weight-specific ingestion decreased more than 2-fold. Larvae and copepodites feeding on S. sulcatum developed at suboptimal rates, survived poorly and showed abnormal morphology in comparison to control individuals fed a good-quality......The ciliate Strombidium sulcatum was used to feed and grow young stages of the copepods Temora longicornis (Muller) and Pseudocalanus elongatus (Boeck). The ciliate was cultured in the laboratory using either bacteria or the green alga Dunaliella sp. as a food source. Young copepodites of both...... Rhodomonas sp. diet. The specific mass of fatty acids in S. sulcatum was much lower than in the Dunaliella sp. diet, However, the fatty acid composition of the protozoan more or less resembled that of the food, lacking long-chain highly unsaturated fatty acids (HUFAs). Sterols only occurred in Dunaliella sp...

  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...... dinoflagellate Alexandrium spp. and a non-toxic control strain of the dinoflagellate Protoceratium reticulatum. The strains varied in their cellular toxin concentration and composition and in lytic activity. High-speed video observations revealed four distinctly different strain-specific feeding responses...... of the copepod during 4 h incubations: (i) the ‘normal’ feeding behavior, in which the feeding appendages were beating almost constantly to produce a feeding current and most (90%) of the captured algae were ingested; (ii) the beating activity of the feeding appendages was reduced by ca. 80% during the initial...

  3. 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...... strategy. Considering that fishing effort in some coastal areas is high and trawling leads to re-suspension of the bottom sediments, it is important to understand these effects on the biology of organisms that utilize sediment habitats in part of their life cycle. This study examined the re...

  4. 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

  5. Sensitivity of the larvivorous copepod species, Mesocyclops pehpeiensis and Megacyclops viridis, to the insect growth regulator, pyriproxyfen

    OpenAIRE

    Wang, Shanqing; Phong, Tran V.; Tuno, Nobuko; Kawada, Hitoshi; Takagi, Masahiro

    2005-01-01

    The effects of the insect growth regulator pyriproxyfen were evaluated on the mortality, fecundity, longevity, and predation capability of 2 species of copepods, Mesocyclops pehpeiensis Hu and Megacyclops viridis (Jurine), under laboratory conditions. Pyriproxyfen showed no significant effects on either the development or reproduction of M. pehpeiensis at 0.1 ppm, which is a 10-fold greater concentration than the reported effective dosage for controlling mosquito larvae (0.01 ppm). In contras...

  6. New species of Pseudodiaptomus (Copepoda: Calanoida) from the salt pans of the Gulf of Kutch, India and a comment on its speciation

    Digital Repository Service at National Institute of Oceanography (India)

    Madhupratap, M.; Haridas, P.

    A new species of calanoid copepod Pseudodiaptomus pankajus (family Pseudodiaptomidae) is described from the north-west coast of India. This species inhabits high saline waters of salt pans. It appears to have evolved allopatrically during...

  7. 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

  8. 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.

  9. The fate of biogenic iron during a phytoplankton bloom induced by natural fertilisation: Impact of copepod grazing

    Science.gov (United States)

    Sarthou, Géraldine; Vincent, Dorothée; Christaki, Urania; Obernosterer, Ingrid; Timmermans, Klaas R.; Brussaard, Corina P. D.

    2008-03-01

    The impact of copepod grazing on Fe regeneration was investigated in a naturally iron-fertilised area during Kerguelen Ocean and Plateau compared Study (KEOPS, Jan.-Feb. 2005). 55Fe-labelled natural plankton assemblages (Navicula spp.) constituted the bulk of the protists whereas microzooplankton (i.e. ciliates and dinoflagellates) were in very low abundance. Copepod grazing on phytoplankton ranged from 0.3 to 2.6 μgC ind -1 d -1 and reflected low utilisation of the food stocks (1-10% of total Chlorophyll a d -1) and low daily rations (0.2-3.3% body C d -1). Copepod grazing resulted in a 1.7-2.3-fold increase in Fe regeneration. Less than 1% of the regenerated Fe was complexed with hydrophobic organic ligands, as determined by extraction onto hydrophobic C18 columns. This suggests that Fe was regenerated as inorganic species and/or bound to freely soluble organic ligands. The biogenic Fe budget established from our study and literature based data indicates that most of the primary production is recycled through the detrital pool, which represents the largest Fe pool (49% of total Fe). Our iron budget further indicates that mesozooplankton and diatoms represent the dominant Fe biomasses above the Kerguelen plateau. The rate of Fe regeneration accounts for half of the Fe demand, strengthening the need for new Fe sources to sustain the massive phytoplankton bloom above the Kerguelen plateau.

  10. Copepods enhance nutritional status, growth and development in Atlantic cod (Gadus morhua L.) larvae — can we identify the underlying factors?

    Science.gov (United States)

    van der Meeren, Terje; Rønnestad, Ivar; Mangor-Jensen, Anders; Galloway, Trina F.; Kjørsvik, Elin; Hamre, Kristin

    2015-01-01

    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. PMID:26038712

  11. iDNA at Sea: Recovery of Whale Shark (Rhincodon typus Mitochondrial DNA Sequences from the Whale Shark Copepod (Pandarus rhincodonicus Confirms Global Population Structure

    Directory of Open Access Journals (Sweden)

    Mark Meekan

    2017-12-01

    Full Text Available The whale shark (Rhincodon typus is an iconic and endangered species with a broad distribution spanning warm-temperate and tropical oceans. Effective conservation management of the species requires an understanding of the degree of genetic connectivity among populations, which is hampered by the need for sampling that involves invasive techniques. Here, the feasibility of minimally-invasive sampling was explored by isolating and sequencing whale shark DNA from a commensal or possibly parasitic copepod, Pandarus rhincodonicus that occurs on the skin of the host. We successfully recovered mitochondrial control region DNA sequences (~1,000 bp of the host via DNA extraction and polymerase chain reaction from whole copepod specimens. DNA sequences obtained from multiple copepods collected from the same shark exhibited 100% sequence similarity, suggesting a persistent association of copepods with individual hosts. Newly-generated mitochondrial haplotypes of whale shark hosts derived from the copepods were included in an analysis of the genetic structure of the global population of whale sharks (644 sequences; 136 haplotypes. Our results supported those of previous studies and suggested limited genetic structuring across most of the species range, but the presence of a genetically unique and potentially isolated population in the Atlantic Ocean. Furthermore, we recovered the mitogenome and nuclear ribosomal genes of a whale shark using a shotgun sequencing approach on copepod tissue. The recovered mitogenome is the third mitogenome reported for the species and the first from the Mozambique population. Our invertebrate DNA (iDNA approach could be used to better understand the population structure of whale sharks, particularly in the Atlantic Ocean, and also for genetic analyses of other elasmobranchs parasitized by pandarid copepods.

  12. 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.

  13. An estimate of the percentage of non-predatory dead variability in coastal zooplankton of the southern Humboldt Current System.

    Science.gov (United States)

    Krautz, M C; Hernández-Miranda, E; Veas, R; Bocaz, P; Riquelme, P; Quiñones, R A

    2017-12-01

    Non-predatory dead variability in zooplankton remains poorly quantified worldwide. Here, we make the first estimation of the percentage of dead organisms in coastal zooplankton communities in the Humboldt Current System (HCS) under in situ conditions. The study was conducted in four coastal sites of the southern HCS (between 36 and 37°S) over a period of one year. Percentages of dead organisms were based on the classification as live or dead of 158,220 holoplankton and 17,591 meroplankton individuals using neutral red staining technique. The percentage of dead organisms in total-zooplankton was between 4.3% in Coronel Bay (summer) and 76.9% in Llico (autumn). The percentage of dead total-holoplankton varied from 4.2% (Itata River Mouth; autumn) to 77.6% (Llico; autumn), while the percentage of dead total-meroplankton ranged from 1.5% to 56.8% in Coronel Bay and Coliumo Bay, respectively. The most abundant taxa analyzed were the copepods Acartia sp., Paracalanus sp., Calanoides sp., Cladocera, Polychaeta, and the eggs of anchoveta Engraulis ringens. Among these taxa, there was a high degree of interspecific variability in the estimation of the dead organisms. The Pearson correlation shows significant relationships between maximum temperature, and minimum salinity, with the percentage of dead individuals of Acartia sp. and Paracalanus sp. Environmental factors explaining those relationships were: the El Niño 2015-2016 event, and freshwater river runoff. The use of vital staining to estimate non-predatory death for total-zooplankton and selected sentinel species is a promising tool to establish baselines to evaluate natural perturbations (e.g. ENSO), and anthropogenic alterations in coastal pelagic ecosystems. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. The prevalence of non-indigenous parasitic copepod (Neoergasilus japonicus) spreads with fishes of pet trade in Kerman, Iran.

    Science.gov (United States)

    Mirzaei, Mohammad; Khovand, Hosein; Kheirandish, Reza

    2016-12-01

    Ergasilids are copepods living in the river mouth of freshwaters and parasitic on Teleost fish family in both natural and artificial environments. So far, 5 species of the copepod have been discovered that belong to the genus Neoergasilus. This copepod is most likely to be disseminated through aquarium trades, aquaculture and over-nutrition, or construction of sand carrying water. The females of Ergasilidae are external parasites attaching to the anal and dorsal fins and sometimes to gills and nasal cavities of fish living in freshwaters. In total, 552 pieces of ornamental fish (301 males and 251 females) with length of 5-10 cm from fish (Poecilia sphenops) species (Singapore, Sandy, Dirigible and scorpion's tail) were collected from ornamental fish stores in different regions of Kerman, Iran during 1 year in 2012-2013 and tested in order to examine Neoergasilus japonicus infestation. From 188 adult females Neoergasilus japonicus specimens recorded on the fish host, 8 (4.26 %) were on the anal, 120 (63.83 %) on the dorsal, 10 (5.32 %), on the pectoral, 45 (23.94 %) on the pelvic, and 5 (2.66 %) on the caudal fins. In this study, the prevalence of parasitic copepod infestation from Dec. to May was 26.31, 27.69, 26.19, 14, 18.75, and 7.5 %, respectively. There was no significant difference between infestation prevalence in indigenous and non-native fishes (P = 0.18). There were significant differences between different months of year in the prevalence and intensity of Neoergasilus japonicas (P < 0.05). There was significant difference between frequency distribution of Neoergasilus Japonicus infestation in different organs (P < 0.05). The male fish infestation (16.3 %) was significantly higher than female fish infestation (5.6 %) (P < 0.05). Considering that the Neoergasilus japonicus was first observed in native and nonnative ornamental fish in Kerman, further studies should be conducted on the copepod infestation in stores supplying ornamental fish

  15. Toxicity and bioaccumulation of three hexabromocyclododecane diastereoisomers in the marine copepod Tigriopus japonicas.

    Science.gov (United States)

    Hong, Haizheng; Lv, Dongmei; Liu, Wanxin; Huang, Lingming; Chen, Leyun; Shen, Rong; Shi, Dalin

    2017-07-01

    The three major hexabromocyclododecane (HBCD) diastereoisomers, i.e. α-, β- and γ-HBCD, have distinct physical and chemical properties that may potentially result in different levels of bioaccumulation and toxicity in aquatic organisms. To assess the impact of diastereomeric variation in HBCDs, the marine copepod Tigriopus japonicus was exposed to α-, β- and γ-HBCD in isolation. Results showed that all the three diastereoisomers had a similar potency to cause growth delay in T. japonicas. Variation was observed in the overall survival rate with exposure to α- and β-HBCD, and this resulted in significantly higher lethal toxicity in T. japonicas than that with exposure to γ-HBCD. Exposure to α-, β- and γ-HBCD led to the generation of ROS in T. japonicas, a possibly toxic mechanism. Both α- and β-HBCD showed a higher potential to induce oxidative stress, which may be a factor in the higher lethal toxicity observed with α- and β-HBCD exposure. It is of note that T. japonicus was found to be more sensitive to all three diastereoisomers in the F1 generation than in the F0 generation. The bioconcentration potential of HBCD diastereoisomers can be ranked in the order α-HBCD>γ-HBCD>β-HBCD and was found to be higher in T. japonicus than has been reported for fish species. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. 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.

  17. 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.

  18. Impact of prey field variability on early cod larval survival: a sensitivity study of a Baltic cod Individual-based Model

    Directory of Open Access Journals (Sweden)

    Jörn O. Schmidt

    2008-06-01

    Full Text Available Baltic larval cod drift, growth and survival use idealised constructed mean prey fields of nauplius distributions. These simulations revealedthe best feeding conditions for Baltic cod larvae longer than 6 mm. For shorter, first feeding larvae (between 4.5 and 6 mm pronounced differences in growth and survival were observed,which depend on food availability and to a lesser degree on ambient temperature. We performed runs with an Individual-based Model (IBM for Baltic cod larvae in order to demonstrate hownatural variability in prey abundance influences the survival success of first feeding larvae. In the Baltic, this larval stage lives mainly between 20 and 40 m depth and feeds exclusivelyon the nauplii of different calanoid copepods (Acartia spp., Pseudocalanus acuspes, Temora longicornis and Centropages hamatus.Prey data obtained from vertically stratified samples in the Bornholm Basin (Baltic Sea in 2001 and 2002 indicate a strong variability at spatial and temporal scales. We calculatedlarval survival and growth in relation to natural variation of prey fields, i.e. species-specific nauplius abundance.The results of the model runs yielded larval survival rates from 60 to 100% if the mean size of nauplii species was taken and lower survival if prey consisted of early nauplius stages only.

  19. The Influence of Individual Variability on Zooplankton Population Dynamics under Different Environmental Conditions

    Science.gov (United States)

    Bi, R.; Liu, H.

    2016-02-01

    Understanding how biological components respond to environmental changes could be insightful to predict ecosystem trajectories under different climate scenarios. Zooplankton are key components of marine ecosystems and changes in their dynamics could have major impact on ecosystem structure. We developed an individual-based model of a common coastal calanoid copepod Acartia tonsa to examine how environmental factors affect zooplankton population dynamics and explore the role of individual variability in sustaining population under various environmental conditions consisting of temperature, food concentration and salinity. Total abundance, egg production and proportion of survival were used to measure population success. Results suggested population benefits from high level of individual variability under extreme environmental conditions including unfavorable temperature, salinity, as well as low food concentration, and selection on fast-growers becomes stronger with increasing individual variability and increasing environmental stress. Multiple regression analysis showed that temperature, food concentration, salinity and individual variability have significant effects on survival of A. tonsa population. These results suggest that environmental factors have great influence on zooplankton population, and individual variability has important implications for population survivability under unfavorable conditions. Given that marine ecosystems are at risk from drastic environmental changes, understanding how individual variability sustains populations could increase our capability to predict population dynamics in a changing environment.

  20. Growth of the peritrich epibiont Zoothamnium intermedium Precht, 1935 (Ciliophora, Peritrichia estimated from laboratory experiments

    Directory of Open Access Journals (Sweden)

    LRP. Utz

    Full Text Available Peritrich ciliates are commonly found colonizing living substrates. Although this a well known phenomenon, biological aspects of this relationship need to be studied in more detail. Assessment of growth rates in peritrichs has been the subject of very few studies. Only species in the genera Carchesium Ehrenberg, 1830 and Vorticella Linnaeus, 1767 had their growth rates evaluated in the field and in the laboratory. In the present study, growth, colonization (colonies/host, and proliferation (zooids/colony rates of the peritrich epibiont Zoothamnium intermedium Precht, 1935 attached to the calanoid copepod Acartia tonsa Dana 1848 were evaluated in the laboratory in two food regimes: bacteria only, and algal based diet. Results showed that growth, colonization, and proliferation rates were similar for both diets. Maximum growth rates obtained for Z. intermedium was 0.85 and 0.83 per day, for bacteria and algae respectively. Maximum colonization rates were 0.5 per day for both diets, and the maximum proliferation rates were 0.44 and 0.42 per day for bacteria and algae respectively. These results demonstrate that Z. intermedium is able to grow at the same rate of other peritrichs on bacterial and algal based diets.

  1. Evolutionary responses to crude oil from the Deepwater Horizon oil spill by the copepod Eurytemora affinis.

    Science.gov (United States)

    Lee, Carol Eunmi; Remfert, Jane Louise; Opgenorth, Taylor; Lee, Kristin M; Stanford, Elizabeth; Connolly, Joseph William; Kim, Jinwoo; Tomke, Sarah

    2017-09-01

    The BP Deepwater Horizon Oil Disaster was the most catastrophic offshore oil spill in U.S. history, yet we still have a poor understanding of how organisms could evolve in response to the toxic effects of crude oil. This study offers a rare analysis of how fitness-related traits could evolve rapidly in response to crude oil toxicity. We examined evolutionary responses of populations of the common copepod Eurytemora affinis residing in the Gulf of Mexico, by comparing crude oil tolerance of populations collected before versus after the Deepwater Horizon oil spill of 2010. In addition, we imposed laboratory selection for crude oil tolerance for ~8 generations, using an E. affinis population collected from before the oil spill. We found evolutionary increases in crude oil tolerance in the wild population following the oil spill, relative to the population collected before the oil spill. The post-oil spill population showed increased survival and rapid development time in the presence of crude oil. In contrast, evolutionary responses following laboratory selection were less clear; though, development time from metamorphosis to adult in the presence of crude oil did become more rapid after selection. We did find that the wild population, used in both experiments, harbored significant genetic variation in crude oil tolerance, upon which selection could act. Thus, our study indicated that crude oil tolerance could evolve, but perhaps not on the relatively short time scale of the laboratory selection experiment. This study contributes novel insights into evolutionary responses to crude oil, in directly examining fitness-related traits before and after an oil spill, and in observing evolutionary responses following laboratory selection.

  2. Coupling between populations of copepod taxa within an estuarine ecosystem and the adjacent offshore regions

    Science.gov (United States)

    McGinty, N.; Johnson, M. P.; Power, A. M.

    2012-07-01

    Population dynamics in open systems are complicated by the interactions of local demography and local environmental forcing with processes occurring at larger scales. A local system such as an estuary or bay may contain a zooplankton population that effectively becomes independent of regional dynamics or the local dynamics may be closely coupled to a broader scale pattern. As an alternative, the details of migration and advection may mean that dynamics in a local system are coupled to other specific areas rather than tracking the overall dynamics at a larger scale. We used a reconstructed time series (1973-1987) for copepod taxa to examine the extent to which zooplankton dynamics in Galway Bay reflect processes in broader areas of the NE Atlantic. Continuous Plankton Recorder (CPR) counts were used to establish time series for nine offshore ecoregions, with the regions themselves defined using underlying patterns of chlorophyll variability. The open nature of Galway Bay was reflected in strong associations between bay zooplankton counts and offshore CPR data in a majority of cases (7/10). For each zooplankton taxon, there were large differences among regions in the degree of association with Galway Bay time series. Akaike weights indicated that one ecoregion tended to be the dominant link for each taxon. This indicates that the zooplankton of the Bay reflect more than the local modification of a regional signal and that different zooplankton in the bay may have separate source regions. The data from Galway Bay also fall within a 'sampling shadow' of the CPR. Later years of the time series showed evidence for changes in phenology, with spring zooplankton peaks generally occurring earlier in the year for smaller species.

  3. Microbial colonization of copepod body surfaces and chitin degradation in the sea

    Science.gov (United States)

    Kirchner, M.

    1995-03-01

    Next to cellulose, chitin (composed of N-acetyl-D-glucosamine sugar units) is the most frequently occurring biopolymer in nature. Among the most common sources of chitin in the marine environment are copepods and the casings of their fecal pellets. During the mineralization of chitin by microorganisms, which occurs chiefly by means of exoenzymes, nitrogen and carbon are returned to the nutrient cycle. In this study, the microbial colonization of the moults (exuviae), carcasses and fecal pellets of Tisbe holothuriae Humes (Copepoda: Harpacticoida) was examined in the laboratory. Results obtained with DAPI staining indicated that a succession of microorganisms from rodshaped bacteria and cocci to starlike aggregates took place, followed by the yeastlike fungus Aureobasidium pullulans (de Bary) Arnaud. No differences were noted between moults from various developmental stages, from nauplius to adult. The ventral sides and extremities of exuviae and carcasses were more rapidly colonized than other parts of the bodies. The casings of fecal pellets were frequently surrounded by bacteria with fimbriae or slime threads. In situ studies of chitin degradation (practical grade chitin from crustacean shells) with the mesh bag technique showed that about 90% of the original substance was lost after 3 months exposure in seawater at temperatures between 10 and 18°C. Chitinase activity was measured in the water at two stations near Helgoland, an island in the North Sea. A higher exoenzymatic activity was found in the rocky intertidal zone, compared to the Station Cable Buoy located between the main and Düne island. These values correspond to the higher bacteria numbers (cfu ml-1) found in the rocky intertidal: 10 to 100× greater than those found at the Cable Buoy Station.

  4. Ecological dispersal barrier across the equatorial Atlantic in a migratory planktonic copepod

    Science.gov (United States)

    Goetze, Erica; Hüdepohl, Patricia T.; Chang, Chantel; Van Woudenberg, Lauren; Iacchei, Matthew; Peijnenburg, Katja T. C. A.

    2017-11-01

    Resolving the large-scale genetic structure of plankton populations is important to understanding their responses to climate change. However, few studies have reported on the presence and geographic extent of genetically distinct populations of marine zooplankton at ocean-basin scales. Using mitochondrial sequence data (mtCOI, 718 animals) from 18 sites across a basin-scale Atlantic transect (39°N-40°S), we show that populations of the dominant migratory copepod, Pleuromamma xiphias, are genetically subdivided across subtropical and tropical waters (global FST = 0.15, global ΦST = 0.21, both P genetic break observed in the equatorial Atlantic (between gyre FCT and ΦCT = 0.23, P genetic transition coincides with an area of low abundance for the species. Transitional regions between the subtropical gyres and the equatorial province also harbor a distinct mitochondrial clade (clade 2), have higher haplotype and nucleotide diversities relative to the northern and/or southern subtropical gyres (e.g., mean h = 0.831 EQ, 0.742 North, 0.594 South, F2,11 = 20.53, P genetically differentiated from the majority of sites in the central gyre and temperate zones of the same hemisphere (significant pairwise ΦST 0.038-0.267, 79% significant). Our observations support the hypothesis that regions of low abundance within species mark areas of suboptimal habitat that serve as dispersal barriers for marine plankton, and we suggest that this may be a dominant mechanism driving the large-scale genetic structure of zooplankton species. Our results also demonstrate the potential importance of the Atlantic equatorial province as a region of evolutionary novelty for the holoplankton.

  5. Effects of Demersal Otter Trawls on the Re-suspension of Copepod Resting Eggs and its Potential Effects on Recruitment

    OpenAIRE

    Hansen, Benni Winding; Drillet, Guillaume; Hay, G; O'Neill, F. G.

    2014-01-01

    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 strategy. Considering that fishing effort in some coastal areas is high and trawling leads to re-suspension of the bottom sediments, it is important to understand these effects on the biology of organism...

  6. Lepeophtheirus simplex sp. n., a caligid copepod (Siphonostomatoida) parasitic on "botete" (bullseye puffer, Sphoeroides annulatus) in Sinaloa, Mexico.

    Science.gov (United States)

    Ho, J S; Gómez, S; Fajer-Avila, E

    2001-01-01

    A new species of caligid copepod, Lepeophtheirus simplex sp. n., parasitic on bullseye puffer, Sphoeroides annulatus (Jenyns) in Sinaloa, Mexico is described. The new species is distinguished from its congeners by the possession of (1) a maxillule with simple dentiform process; (2) a sternal furca with sharply pointed, curved tines; (3) a 2-segmented exopod of leg 3 with simple, slender spine on proximal segment; (4) a 3-segmented exopod of leg 4 with a long proximal, outer spine; and (5) the terminal claw of male antenna with a large, tridentate, medial protuberance.

  7. Distribution and production of plankton communities in the subtropical convergence zone of the Sargasso Sea. II. Protozooplankton and copepods

    DEFF Research Database (Denmark)

    Andersen, Nikolaj G.; Nielsen, Torkel Gissel; Jakobsen, Hans Henrik

    2011-01-01

    The oligotrophic Sargasso Sea in the western part of the North Atlantic Ocean is influenced by a complex set of oceanographic features that might introduce nutrients and enhance productivity in certain areas. To increase our understanding of the variability in plankton communities and to determine...... and metazooplankton were investigated at 33 stations along 3 north to south transects ranging from 64 to 70 degrees W to a depth of 400 m. Copepods dominated the metazooplankton, while heterotrophic athecate dinoflagellates dominated the protozoan biomass. Other important groups were appendicularians, gastropod...

  8. Lethal and sub-lethal effects of cypermethrin and glyphosate on the freshwater’s copepod, Acanthocyclops robustus

    OpenAIRE

    AM Houssou; EJ Daguégué; E Montchowui

    2017-01-01

    The study aims to evaluate the acute and chronic toxicity of cypermethrin and glyphosate to a freshwater’s copepod, Arcanthocyclops robustus. The acute sensibility was assessed by estimating lethal concentrations. Then the chronic exposure allowed to assess the effects of low concentrations (0.2489 ppb and 0.4978 ppb respectively 10 % and 20 % of LC50 at 48 h of cypermethrin and 1.3 ppm and 2.6 ppm respectively for glyphosate) on the species. The estimated lethal concentrations at...

  9. 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

    to the controls (***P test system showed that the major fractions (&SIM; 50-80%) were associated to particulate material. Our findings indicate that development and reproduction in N. spinipes are sensitive to the tested PBDEs......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...

  10. Growth phase of the diatom Skeletonema marinoi influences the metabolic profile of the cells and the selective feeding of the copepod Calanus spp

    DEFF Research Database (Denmark)

    Barofsky, A.; Simonelli, P.; Vidoudez, V.

    2010-01-01

    Copepods dominate the biomass of marine zooplankton and through their prey selection they act as top-down regulators of planktonic communities. We investigated feeding preference of copepods in the presence of the diatom Skeletonema marinoi at different time points throughout the development...... in both laboratory and field settings. In parallel, we monitored cellular metabolites of the diatom using a metabolomic approach. Complex changes in the metabolic profile occur during development of a culture. Since no obvious effect of nutrient quality and cell size was involved, we suggest that changes...

  11. Occurrence and effects of the parasitic copepod Salmincola carpionis on salmonids in the Nikko District, central Japan

    Science.gov (United States)

    Nagasawa, Kazuya; Ikuta, Kazumasa; Nakamura, Hidefumi; Shikama, Toshio; Kitamura, Shoji

    1998-06-01

    Salmincola carpionis (Krøyer, 1837) occurred on brook trout ( Salvelinus fontinalis) and whitespotted charr ( Salvelinus leucomaenis) reared at a fisheries research institute in the Nikko District, central Japan, and also on a wild population of the latter species that had returned for spawning from a lake to streams near the institute. Its infection levels on these salmonids were associated with age and size of fish and the location of rearing ponds, older (larger) fish reared in the lower-located ponds being more frequently and heavily infected than smaller (younger) fish from the upper-located ponds. Swellings were observed at sites where the bulla of S. carpionis was deeply implanted. The condition factor of heavily infected (>50 copepods) fish was lower than those of lightly infected fish (1-18 copepods). Salmincola carpionis did not occur on lake trout ( Salvelinus namaycush) which belong to the subgenus Cristivomer, as well as on salmonids of the genera Oncorhynchus and Salmo, possibly due strict host specificity.

  12. Production, oxygen respiration rates, and sinking velocity of copepod fecal pellets: Direct measurements of ballasting by opal and calcite

    DEFF Research Database (Denmark)

    Ploug, H.; Iversen, M.H.; Koski, Marja

    2008-01-01

    Production, oxygen uptake, and sinking velocity of copepod fecal pellets egested by Temora longicornis were measured using a nanoflagellate (Rhodomonas sp.), a diatom (Thalassiosira weissflogii), or a coccolithophorid (Emiliania huxleyi) as food sources. Fecal pellet production varied between 0.......8 pellets ind(-1) h(-1) and 3.8 pellets ind(-1) h(-1) and was significantly higher with T. weissflogii than with the other food sources. Average pellet size varied between 2.2 X 10(5) mu m(3) and 10.0 X 10(5) mu m(3). Using an oxygen microsensor, small-scale oxygen fluxes and microbial respiration rates...... were measured directly with a spatial resolution of 2 mu m at the interface of copepod fecal pellets and the surrounding water. Averaged volume-specific respiration rates were 4.12 fmol O-2 mu m(-3) d(-1), 2.86 fmol O-2 mu m(-3) d(-1), and 0.73 fmol O-2 mu m(-3) d(-1) in pellets produced on Rhodomonas...

  13. Morphology and pathology of the ectoparasitic copepod, Nicothoë astaci ('lobster louse') in the European lobster, Homarus gammarus.

    Science.gov (United States)

    Wootton, Emma C; Pope, Edward C; Vogan, Claire L; Roberts, Emily C; Davies, Charlotte E; Rowley, Andrew F

    2011-09-01

    Ectoparasitic copepods have been reported in a wide range of aquatic animals, including crustacean shellfish. However, with the exception of the salmon louse, Lepeophtheirus salmonis, our knowledge of such parasites in commercial species is rudimentary. The current study examines the morphology and pathology of the parasitic copepod, Nicothoë astaci (the 'lobster louse') in its host, the European lobster, Homarus gammarus. Lobsters were sampled from waters surrounding Lundy Island (Bristol Channel, UK) and all individuals collected were found to harbour female adult N. astaci in their gills, with a mean of 47·3 parasites/lobster. The majority of N. astaci were found in the basal region of pleurobranch gills. The parasite was found to attach to gill filaments via its oral sucker, maxillae and maxillipeds, and to feed on host haemolymph (blood) through a funnel-like feeding channel. It caused varying degrees of damage to the host gill, including occlusion of gill filaments and disruption to the vascular system in the central axis. Although there was evidence of extensive host response (haemocytic infiltration) to the parasite, it was displaced from the parasite attachment site and thus was observed in the central gill axis below. The region of gill filament immediately underlying the parasite feeding channel was devoid of such activity suggesting that the parasite interferes with the cellular defence and haemostatic mechanisms of the lobster in order to maintain invasion of the host.

  14. Diversity and abundance of littoral cladocerans and copepods in nine Ecuadorian highland lakes

    Directory of Open Access Journals (Sweden)

    Leticia E Torres

    2006-03-01

    Full Text Available The diversity and abundance of littoral cladocerans and copepods were studied in nine lakes at Reserva Ecológica Cayambe-Coca (Páramo de Guamaní, Ecuador. Six samples were taken in the littoral zone of each lake using a 500 µm mesh plankton conic net. One species of cladocerans (Ephemeroporus acanthoides is reported for the first time in Ecuador. The diversity (H’ and evenness (E of the lakes were determined and correlated with PCA axes based on their environmental variables. The principal parameters that distinguished these lakes were altitude and pH, an unexpected finding considering that the altitudinal range was very small. Lake size is of secondary importance for this group of lakes. None of the environmental axes correlated with H’ or E; nevertheless, a larger than expected species richness was found in a small oligotrophic lake with a high level of DO. Based on our results, we hypothesize that altitude and pH are important factors determining the zooplankton diversity (directly or indirectly in highland lakes. Rev. Biol. Trop. 54 (1: 131-137. Epub 2006 Mar 31.La diversidad y abundancia de cladóceros y copépodos de la zona litoral de nueve lagos fue estudiada en la Reserva Ecológica Cayambe-Coca (Páramo de Guamaní, Ecuador. Seis muestras fueron tomadas en la zona litoral de cada lago utilizando una red conica para plancton de 500 µm de apertura. Una especie de cladócero (Ephemeroporus acanthoides es informada por primera vez en Ecuador. La diversidad (H’ y equitatividad (E fueron determinadas y correlacionadas con los ejes del PCA basado en variables ambientales de los lagos. Los principales parámetros que distinguen estos lagos fueron la altitud y el pH, hallazgo inesperado dado el estrecho ámbito altitudinal. El tamaño parece ser secundario en importancia para este grupo de lagos. No se encontró una correlación significativa entre ninguno de los ejes ambientales y los indices H’ o E; sin embargo, la riqueza de

  15. 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.

    period and several species move into the high saline coastal waters. On recovery of the salinity, they repopulate and flourish in the estuary. Copepods are generally grouped on salinity preference, and in this case 3 categories are recognized viz. wide (5...

  16. Seasonal changes in food quantity and quality of the common North Sea copepods Temora longicornis and Pseudocalanus elongatus: a bioassay approach

    DEFF Research Database (Denmark)

    Koski, Marja; Dutz, Jörg; Klein Breteler, W.

    2010-01-01

    and quality were measured as the concentrations of chl a, specific phytoplankton pigments, particulate organic carbon (POC), particulate organic nitrogen (PON), fatty acids, and sterols. The egg production of both copepods was low when feeding on seston collected in winter, but increased to peak values...

  17. Amsterdam Expeditions to the West Indian Islands, Report 42. Harpacticoid copepods from the West Indian Islands: Canuellidae and Longipediidae (Copepoda, Harpacticoida)

    NARCIS (Netherlands)

    Fiers, Frank

    1984-01-01

    This paper is the first of a series dealing with the systematics of harpacticoid copepods collected during the West Indian Expeditions of the University of Amsterdam. In the present paper a new species, Scottolana antillensis n. sp., is described. Furthermore, Ellucana secunda Coull, 1971, is

  18. systems, pelagic fish of the southern Benguela are dominated

    African Journals Online (AJOL)

    denise

    diatom carbon and nitrogen efficiently (van der Lingen. 1998a). Field studies in the southern Benguela have ... cyclopoid copepods, calanoid copepods and diatoms. Virtually all prey items ingested by sardine were ... Sardine were collected during research cruises under- taken in October and November 1992, November ...

  19. Download this PDF file

    African Journals Online (AJOL)

    Malcom, 1981; Egborge et al., 1994; Beaver & Havens, 1996). One noted characteristics of the crustacean fauna in this study is the dominance of Calanoida over the cyclopoid copepods in most of the stations. Green (1972) reported the predominance of cyclopoid copepods over the calanoids in some crater lakes in.

  20. Aquatic Resources of Rocky Mountain Arsenal Adams County, Colorado

    Science.gov (United States)

    1989-09-01

    Pseudochydorus globosus, Simocephalus vetulus , and some daphnids and copepods are found in vegetated shallows. -45- DERBY • LADORA MARY 1200 1000 N 800U M B E R...x D. parvula X xID. rosea X x x Simocephalus vetulus x Ostracoda sp. XI Copepoda Copepod nauplii x x X Calanoida Calanoid copepodids X x XI

  1. Influence of prey availability on the distribution of Dusky Kob ...

    African Journals Online (AJOL)

    The stomach contents of 391 juvenile dusky kob Argyrosomus japonicus (23–805 mm total length, TL) from the Great Fish River estuary were analysed. Early juveniles (<50 mm TL) fed predominantly on mysids and calanoid copepods. As the juveniles increased in size, copepods were replaced by teleost prey, but mysids ...

  2. Barriers in the pelagic: population structuring of Calanus helgolandicus and C. euxinus in European waters

    NARCIS (Netherlands)

    Yebra, L.; Bonnet, D.; Harris, R.P.; Lindeque, P.K.; Peijnenburg, K.T.C.A.

    2011-01-01

    Molecular studies of marine plankton have shown that ecological and/or environmental barriers play an important role in separating populations. Calanoid copepods are central in marine ecosystems, and dramatic biogeographical shifts in copepod assemblages associated with recent climate warming have

  3. Barriers in the pelagic: population structuring of Calanus helgolandicus and C. euxinus in European waters.

    NARCIS (Netherlands)

    Yebra, L.; Bonnet, D.; Harris, R.P.; Lindeque, P.K.; Peijnenburg, K.T.C.A.

    2011-01-01

    Molecular studies of marine plankton have shown that ecological and/or environmental barriers play an important role in separating populations. Calanoid copepods are central in marine ecosystems, and dramatic biogeographical shifts in copepod assemblages associated with recent ­climate warming have

  4. CellTracker Green labelling vs. rose bengal staining: CTG wins by points in distinguishing living from dead anoxia-impacted copepods and nematodes

    Directory of Open Access Journals (Sweden)

    M. Grego

    2013-07-01

    Full Text Available Hypoxia and anoxia have become a key threat to shallow coastal seas. Much is known about their impact on macrofauna, less on meiofauna. In an attempt to shed more light on the latter group, in particular from a process-oriented view, we experimentally induced short-term anoxia (1 week in the northern Adriatic Sea (Mediterranean and examined the two most abundant meiofauna taxa – harpacticoid copepods and nematodes. Both taxa also represent different ends of the tolerance spectrum, with copepods being the most sensitive and nematodes among the most tolerant. We compared two methods: CellTracker Green (CTG – new labelling approach for meiofauna – with the traditional rose bengal (RB staining method. CTG binds to active enzymes and therefore colours live organisms only. The two methods show considerable differences in the number of living and dead individuals of both meiofauna taxa. Generally, RB will stain dead but not yet decomposed copepods and nematodes equally as it does live ones. Specifically, RB significantly overestimated the number of living copepods in all sediment layers in anoxic samples, but not in any normoxic samples. In contrast, for nematodes, the methods did not show such a clear difference between anoxia and normoxia. RB overestimated the number of living nematodes in the top sediment layer of normoxic samples, which implies an overestimation of the overall live nematofauna. For monitoring and biodiversity studies, the RB method might be sufficient, but for more precise quantification of community degradation, especially after an oxygen depletion event, CTG labelling is a better tool. Moreover, it clearly highlights the surviving species within the copepod or nematode community. As already accepted for foraminiferal research, we demonstrate that the CTG labelling is also valid for other meiofauna groups.

  5. CellTracker Green labelling vs. rose bengal staining: CTG wins by points in distinguishing living from dead anoxia-impacted copepods and nematodes

    Science.gov (United States)

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

    2013-07-01

    Hypoxia and anoxia have become a key threat to shallow coastal seas. Much is known about their impact on macrofauna, less on meiofauna. In an attempt to shed more light on the latter group, in particular from a process-oriented view, we experimentally induced short-term anoxia (1 week) in the northern Adriatic Sea (Mediterranean) and examined the two most abundant meiofauna taxa - harpacticoid copepods and nematodes. Both taxa also represent different ends of the tolerance spectrum, with copepods being the most sensitive and nematodes among the most tolerant. We compared two methods: CellTracker Green (CTG) - new labelling approach for meiofauna - with the traditional rose bengal (RB) staining method. CTG binds to active enzymes and therefore colours live organisms only. The two methods show considerable differences in the number of living and dead individuals of both meiofauna taxa. Generally, RB will stain dead but not yet decomposed copepods and nematodes equally as it does live ones. Specifically, RB significantly overestimated the number of living copepods in all sediment layers in anoxic samples, but not in any normoxic samples. In contrast, for nematodes, the methods did not show such a clear difference between anoxia and normoxia. RB overestimated the number of living nematodes in the top sediment layer of normoxic samples, which implies an overestimation of the overall live nematofauna. For monitoring and biodiversity studies, the RB method might be sufficient, but for more precise quantification of community degradation, especially after an oxygen depletion event, CTG labelling is a better tool. Moreover, it clearly highlights the surviving species within the copepod or nematode community. As already accepted for foraminiferal research, we demonstrate that the CTG labelling is also valid for other meiofauna groups.

  6. Growth and ontogeny of the tapeworm Schistocephalus solidus in its copepod first host affects performance in its stickleback second intermediate host

    Directory of Open Access Journals (Sweden)

    Benesh Daniel P

    2012-05-01

    Full Text Available Abstract Background For parasites with complex life cycles, size at transmission can impact performance in the next host, thereby coupling parasite phenotypes in the two consecutive hosts. However, a handful of studies with parasites, and numerous studies with free-living, complex-life-cycle animals, have found that larval size correlates poorly with fitness under particular conditions, implying that other traits, such as physiological or ontogenetic variation, may predict fitness more reliably. Using the tapeworm Schistocephalus solidus, we evaluated how parasite size, age, and ontogeny in the copepod first host interact to determine performance in the stickleback second host. Methods We raised infected copepods under two feeding treatments (to manipulate parasite growth, and then exposed fish to worms of two different ages (to manipulate parasite ontogeny. We assessed how growth and ontogeny in copepods affected three measures of fitness in fish: infection probability, growth rate, and energy storage. Results Our main, novel finding is that the increase in fitness (infection probability and growth in fish with larval size and age observed in previous studies on S. solidus seems to be largely mediated by ontogenetic variation. Worms that developed rapidly (had a cercomer after 9 days in copepods were able to infect fish at an earlier age, and they grew to larger sizes with larger energy reserves in fish. Infection probability in fish increased with larval size chiefly in young worms, when size and ontogeny are positively correlated, but not in older worms that had essentially completed their larval development in copepods. Conclusions Transmission to sticklebacks as a small, not-yet-fully developed larva has clear costs for S. solidus, but it remains unclear what prevents the evolution of faster growth and development in this species.

  7. Growth and ontogeny of the tapeworm Schistocephalus solidus in its copepod first host affects performance in its stickleback second intermediate host

    Science.gov (United States)

    2012-01-01

    Background For parasites with complex life cycles, size at transmission can impact performance in the next host, thereby coupling parasite phenotypes in the two consecutive hosts. However, a handful of studies with parasites, and numerous studies with free-living, complex-life-cycle animals, have found that larval size correlates poorly with fitness under particular conditions, implying that other traits, such as physiological or ontogenetic variation, may predict fitness more reliably. Using the tapeworm Schistocephalus solidus, we evaluated how parasite size, age, and ontogeny in the copepod first host interact to determine performance in the stickleback second host. Methods We raised infected copepods under two feeding treatments (to manipulate parasite growth), and then exposed fish to worms of two different ages (to manipulate parasite ontogeny). We assessed how growth and ontogeny in copepods affected three measures of fitness in fish: infection probability, growth rate, and energy storage. Results Our main, novel finding is that the increase in fitness (infection probability and growth in fish) with larval size and age observed in previous studies on S. solidus seems to be largely mediated by ontogenetic variation. Worms that developed rapidly (had a cercomer after 9 days in copepods) were able to infect fish at an earlier age, and they grew to larger sizes with larger energy reserves in fish. Infection probability in fish increased with larval size chiefly in young worms, when size and ontogeny are positively correlated, but not in older worms that had essentially completed their larval development in copepods. Conclusions Transmission to sticklebacks as a small, not-yet-fully developed larva has clear costs for S. solidus, but it remains unclear what prevents the evolution of faster growth and development in this species. PMID:22564512

  8. Diapause in copepods (Crustacea) from ephemeral habitats with different hydroperiods in Everglades National Park (Florida, U.S.A.)

    Science.gov (United States)

    Bruno, M.C.; Loftus, W.F.; Reid, J.W.; Perry, S.A.

    2001-01-01

    Water management practices in the Everglades have severely stressed the natural system, particularly by reducing the hydroperiods of much of the region. During the dry season of 1999, we investigated the influence of hydroperiod on the species composition and dormancy patterns of freshwater copepod communities in seasonal wetlands of Everglades National Park, Florida, U.S.A. The habitats were characterized by an annual dry season, from December through June. We sampled at two locations: the Long Pine Key area of the Rocky Glades region (short hydroperiod, ca. 4-5 months), and western Taylor Slough (intermediate hydroperiod, ca. 8-10 months). Both areas have experienced a reduction in natural hydroperiods and an increase in the frequency of dry-down. We collected weekly plankton samples from Rocky Glades solution holes to assess the potential species pool of copepods. To document the taxa capable of surviving dry-down by resting, we performed three immersion trials in which we rehydrated, in laboratory aquaria, sediment patches from solution holes and surface soils from all stations. Only a subset of the planktonic species collected emerged from the dried sediments. The cyclopoids Microcyclops rubellus and Paracyclops poppei were dominant. This is the first record of diapause for P. poppei. Species distributions from the different hydroperiod soil patches indicated that more diapausing species occurred at the sites that dried for shorter periods. Emerging individuals of M. rubellus and P. poppei were mainly ovigerous females, demonstrating a resting strategy seldom before recorded. The cyclopoid Diacyclops nearcticus had not been previously reported to diapause, but they emerged from the dried sediments in our trials. Our collections included six new records for Florida: Diacyclops nearcticus, Megacyclops latipes, Orthocyclops modestus, Elaphoidella marjoryae, Bryocamptus sp. and Bryocamptus cf. newyorkensis. Paracyclops poppei, Macrocyclops fuscus and

  9. A deep transcriptomic resource for the copepod crustacean Labidocera madurae: A potential indicator species for assessing near shore ecosystem health.

    Directory of Open Access Journals (Sweden)

    Vittoria Roncalli

    Full Text Available Coral reef ecosystems of many sub-tropical and tropical marine coastal environments have suffered significant degradation from anthropogenic sources. Research to inform management strategies that mitigate stressors and promote a healthy ecosystem has focused on the ecology and physiology of coral reefs and associated organisms. Few studies focus on the surrounding pelagic communities, which are equally important to ecosystem function. Zooplankton, often dominated by small crustaceans such as copepods, is an important food source for invertebrates and fishes, especially larval fishes. The reef-associated zooplankton includes a sub-neustonic copepod family that could serve as an indicator species for the community. Here, we describe the generation of a de novo transcriptome for one such copepod, Labidocera madurae, a pontellid from an intensively-studied coral reef ecosystem, Kāne'ohe Bay, Oahu, Hawai'i. The transcriptome was assembled using high-throughput sequence data obtained from whole organisms. It comprised 211,002 unique transcripts, including 72,391 with coding regions. It was assessed for quality and completeness using multiple workflows. Bench-marking-universal-single-copy-orthologs (BUSCO analysis identified transcripts for 88% of expected eukaryotic core proteins. Targeted gene-discovery analyses included searches for transcripts coding full-length "giant" proteins (>4,000 amino acids, proteins and splice variants of voltage-gated sodium channels, and proteins involved in the circadian signaling pathway. Four different reference transcriptomes were generated and compared for the detection of differential gene expression between copepodites and adult females; 6,229 genes were consistently identified as differentially expressed between the two regardless of reference. Automated bioinformatics analyses and targeted manual gene curation suggest that the de novo assembled L. madurae transcriptome is of high quality and completeness. This

  10. Seasonal abundance of the demersal copepod Pseudodiaptomus cokeri (Calanoidea: Pseudodiaptomidae in a Caribbean estuarine environment

    Directory of Open Access Journals (Sweden)

    Eduardo Rios Jara

    1998-09-01

    Full Text Available Seasonal abundance variations of the demersal copepod Pseudodiaptomus cokeriwere examinated at three locations (center, north shore and south shore in Phosphorescent Bay, Puerto Rico, throughout an annual cycle. Nocturnal oblique tows (21:00-23:00 hr were taken biweekly (three replicates at each location with a conical net (mouth diameter = 0.5 m; mesh size = 135 µm and a standard calibrated flowmeter. Water temperature and salinity measurements were taken at the surface and near the bottom in each location before towing activities using a SCT meter. Chlorophyll-a concentrations were fluorometrically determined. The adult and copepodite stages of this species accounted for approximately 1.6% of the annual mean total zooplankton abundance of the bay. Higher abundance of P. cokeri (mean +1 SD = 4 191 + 1 444 individuals m-3 was associated with cool water temperatures and dry conditions (cool/dry season which prevailed between December and March relative to the period between April and November (warm/wet season with lower abundance. Fluctuations of this population followed progressive increments in chlorophyll-a concentrations at the three sampling stations (One-way ANOVA, pEste estudio analiza las variaciones estacionales en abundancia del copépodo demersal Pseudodiaptomus cokeri en tres localidades de muestreo (centro y orillas norte y sur de Bahía Fosforescente, Puerto Rico, durante un ciclo anual. Se realizaron arrastres oblicuos por triplicado durante la noche (21:00-23:00 hr en las tres localidades cada quince dias con una red cónica (diámetro = 0.5 m; luz de malla = 135 µm y un flujómetro standard calibrado. La temperatura del agua y su salinidad se registraron en la superficie y cerca del fondo en cada localidad antes de los arrastres usando un sensor SCT. La concentración de clorofila-a se determinó mediante fluorometría. Los estadios adulto y copepodito de esta especie representaron aproximadamente el 1.6% de la abundancia

  11. Preliminary results: Deep sea oil spill in the Arctic – effects of pyrene on overwintering Calanus copepods

    DEFF Research Database (Denmark)

    Toxværd, Kirstine Underbjerg; Dinh, Khuong Van; Hjorth, Morten

    2017-01-01

    Polar Oceans are some of the least impacted by human activities due to seasonal or permanent sea ice that limits human access. Projections of future polar ice loss suggest that the impact will increase substantially because of changing environmental conditions and pollution. Arctic Oceans hold...... with two species of Artic copepod to study the impact of long term exposure to oil during polar night. We used the ecological important Calanus hyperboreus (winter breeder) and C. glacialis (spring breeder) as tests species, and quantified effects on the fitness-related traits mortality, egg production...... seawater. Effects diminish over time, and feeding rate is recovered after 14 days without exposure to oil. Both egg production and feeding rate of C. glacialis is impacted by exposure in a concentration dependent manner after transfer to clean seawater. These findings suggest, that long term oil exposure...

  12. Sensitivity of Calanus spp. copepods to environmental changes in the North Sea using life-stage structured models

    DEFF Research Database (Denmark)

    Maar, Marie; Møller, Eva Friis; Gürkan, Zeren

    2013-01-01

    . finmarchicus in this region. The aim of this study is to use life-stage structured models of the two Calanus species embedded in a 3D coupled hydrodynamic-biogeochemical model to investigate how the biogeography of C. finmarchicus and C. helgolandicus is modified by changes in ± 2°C sea water temperatures......, overwintering and oceanic inflow in the North Sea. Life-stage structured models are validated against CPR data and vertical distributions north of the Dogger Bank in the North Sea for the reference year 2005. The model shows that 1) ± 2°C changes from the current level mainly influence the seasonal patterns......The copepods Calanus finmarchicus and C. helgolandicus co-exist in the North Sea, but their spatial distribution and phenology are very different. Long-term changes in their distributions seem to occur due to climate change resulting in a northward extension of C. helgolandicus and a decline of C...

  13. Qualitative use of Dynamic Energy Budget theory in ecotoxicology. Case study on oil contamination and Arctic copepods

    Science.gov (United States)

    Klok, Chris; Hjorth, Morten; Dahllöf, Ingela

    2012-10-01

    The Dynamic Energy Budget (DEB) theory provides a logic and consistent framework to evaluate ecotoxicological test results. Currently this framework is not regularly applied in ecotoxicology given perceived complexity and data needs. However, even in the case of low data availability the DEB theory is already useful. In this paper we apply the DEB theory to evaluate the results in three previously published papers on the effects of PAHs on Arctic copepods. Since these results do not allow for a quantitative application we used DEB qualitatively. The ecotoxicological results were thereby set in a wider ecological context and we found a logical explanation for an unexpected decline in hatching success described in one of these papers. Moreover, the DEB evaluation helped to derive relevant ecological questions that can guide future experimental work on this subject.

  14. Variation in tolerance to common marine pollutants among different populations in two species of the marine copepod Tigriopus.

    Science.gov (United States)

    Sun, Patrick Y; Foley, Helen B; Bao, Vivien W W; Leung, Kenneth M Y; Edmands, Suzanne

    2015-10-01

    Geographical variation in chemical tolerance within a species can significantly influence results of whole animal bioassays, yet a literature survey showed that the majority of articles using bioassays did not provide detail on the original field collection site of their test specimens confounding the ability for accurate replication and comparison of results. Biological variation as a result of population-specific tolerance, if not addressed, can be misinterpreted as experimental error. Our studies of two marine copepod species, Tigriopus japonicus and Tigriopus californicus, found significant intra- and inter-specific variation in tolerance to copper and tributyltin. Because both species tolerate copper concentrations orders of magnitude higher than those found in coastal waters, difference in copper tolerance may be a by-product of adaptation to other stressors such as high temperature. Controlling for inter-population tolerance variation will greatly strengthen the application of bioassays in chemical toxicity tests.

  15. Individual and mixture acute toxicity of model pesticides chlordecone and pyriproxyfen in the estuarine copepod Eurytemora affinis.

    Science.gov (United States)

    Legrand, Elena; Boulangé-Lecomte, Céline; Restoux, Gwendal; Trémolet, Gauthier; Duflot, Aurélie; Forget-Leray, Joëlle

    2017-02-01

    Due to the increase in the use of phytosanitary products during the last few decades, the importance to study the effect of pesticide mixtures has been established. In this study, we investigated the acute toxicity of two model insecticides, chlordecone (CLD) and pyriproxyfen (PXF), alone and in mixtures, in the estuarine copepod Eurytemora affinis. After 48 h of exposure, the relative LC50 were 73.24 and 131.61 μg/L for PXF and CLD, respectively. The lower concentration tested (10 μg/L) did not affect the mortality of E. affinis whatever the considered chemical compound. To understand the interaction between compounds in mixture, the results were fitted to the concentration addition, Vølund, and Hewlett models. The best fit was obtained with the Hewlett model, suggesting a synergistic effect of the mixture.

  16. Notes on the Egg Bearing Cyclopoid Copepod, Oithona similis Claus, 1866 of the Arabian Sea

    Directory of Open Access Journals (Sweden)

    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.

  17. Temperature and food quantity effects on the harpacticoid copepod Nitocra spinipes: Combining in vivo bioassays with population modeling

    Science.gov (United States)

    Bui, Thuy T.; Lundström Belleza, Elin; Brinkmann, Markus; Hollert, Henner; Breitholtz, Magnus

    2017-01-01

    The harpacticoid copepod Nitocra spinipes has become a popular model species for toxicity testing over the past few decades. However, the combined influence of temperature and food shortage, two climate change-related stressors, has never been assessed in this species. Consequently, effects of three temperatures (15, 20 and 25°C) and six food regimes (between 0 and 5 × 105 algal cells/mL) on the life cycle of N. spinipes were examined in this study. Similarly to other copepod species, development times and brood sizes decreased with rising temperatures. Mortality was lowest in the 20°C temperature setup, indicating a close-by temperature optimum for this species. Decreasing food concentrations led to increased development times, higher mortality and a reduction in brood size. A sex ratio shift toward more females per male was observed for increasing temperatures, while no significant relationship with food concentration was found. Temperature and food functions for each endpoint were integrated into an existing individual-based population model for N. spinipes which in the future may serve as an extrapolation tool in environmental risk assessment. The model was able to accurately reproduce the experimental data in subsequent verification simulations. We suggest that temperature, food shortage, and potentially other climate change-related stressors should be considered in environmental risk assessment of chemicals to account for non-optimal exposure conditions that may occur in the field. Furthermore, we advocate combining in vivo bioassays with population modeling as a cost effective higher tier approach to assess such considerations. PMID:28334000

  18. Ecological distribution of pelagic copepods and species relationship to acidification, liming and natural recovery in a boreal area

    Directory of Open Access Journals (Sweden)

    Svein Birger WÆRVÅGEN

    2003-02-01

    Full Text Available 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 increased numerically during acidification, both because it is tolerant to acidic environments and because fish predation diminished or disappeared altogether. After chemical recovery, H. saliens, having an endogenous egg-bank, most readily produced viable populations with numerical abundance depending upon fish predation pressure. Thermocyclops oithonoides and Cyclops scutifer were negatively affected by strongly acidic environments, whereas Mesocyclops leuckarti tolerated acidic conditions better. All three cyclopoid species increased in abundance after chemical recovery, most probably from small residual populations. The hypolimnetic C. scutifer faced dispersal problems in re-establishing following liming. Deep lakes (>20 m harboured considerable residual populations of C. scutifer which recovered rapidly to pre-acidic conditions. Cyclops abyssorum inhabited the pelagial during early recovery of formerly chronically acidified lakes as a fugitive species, probably due to rapid dispersal capacities. Littoral cyclopoids, such as Acanthocyclops vernalis and Diacyclops nanus, were commonly distributed in the free waters of the most acidic lakes (pH = 4.5-4.8, but disappeared from the pelagial shortly after chemical recovery. The total community of pelagic copepods forms a promising tool to identify historical acidification and trajectories of recovery in the freshwater environment.

  19. Multiple gene analyses of caligid copepods indicate that the reduction of a thoracic appendage in Pseudocaligus represents convergent evolution.

    Science.gov (United States)

    Freeman, Mark A; Anshary, Hilal; Ogawa, Kazuo

    2013-11-28

    The Caligidae is a family of parasitic copepods containing over 30 recognised genera. They are commercially important parasites as they cause disease in numerous finfish aquaculture facilities globally. Morphological features are used to distinguish between the genera and Pseudocaligus has traditionally been differentiated from Caligus solely by the presence of a much reduced form of the fourth thoracic leg. Currently there are numerous DNA sequences available for Caligus spp. but only the type species, Pseudocaligus brevipedis, has molecular data available, so systematic studies using molecular phylogenetic analyses have been limited. Three gene regions, SSU rDNA, 16S and CO1, for Pseudocaligus fugu from puffer fish from Japan and Pseudocaligus uniartus from rabbit fish from Indonesia are sequenced and molecular phylogenetic analyses performed in order to infer phylogenetic relationships between Pseudocaligus and other caligid copepods. The analysis revealed that there was no discrete grouping of Pseudocaligus spp. and that they had a polyphyletic distribution within Caligus taxa. Pseudocaligus fugu grouped with Caligus elongatus and contained a unique synapomorphy in the SSU rDNA region only seen in members of that clade. Pseudocaligus uniartus formed a well-supported group, in the SSU rDNA analyses, with a Caligus sp. that also infects rabbit fish, but was unresolved in the other analyses. Pseudocaligus brevipedis consistently and robustly grouped with Caligus curtus and C. centrodonti in all analyses. The majority of Lepeophtheirus spp. form a monophyletic sister group to the Caligus clade; however, L. natalensis is unresolved in all analyses and does not form part of the main Lepeophtheirus clade. These findings do not support the morphological-based distinction between Pseudocaligus and Caligus, suggesting that the reduced fourth leg is a feature that has evolved on multiple occasions throughout caligid evolution. Congruent molecular phylogenetic data support

  20. BDE-47 induces oxidative stress, activates MAPK signaling pathway, and elevates de novo lipogenesis in the copepod Paracyclopina nana.

    Science.gov (United States)

    Lee, Min-Chul; Puthumana, Jayesh; Lee, Seung-Hwi; Kang, Hye-Min; Park, Jun Chul; Jeong, Chang-Bum; Han, Jeonghoon; Hwang, Dae-Sik; Seo, Jung Soo; Park, Heum Gi; Om, Ae-Son; Lee, Jae-Seong

    2016-12-01

    Brominated flame retardant, 2, 2', 4, 4'-tetrabromodiphenyl ether (BDE-47), has received grave concerns as a persistent organic pollutant, which is toxic to marine organisms, and a suspected link to endocrine abnormalities. Despite the wide distribution in the marine ecosystem, very little is known about the toxic impairments on marine organisms, particularly on invertebrates. Thus, we examined the adverse effects of BDE-47 on life history trait (development), oxidative markers, fatty acid composition, and lipid accumulation in response to BDE-47-induced stress in the marine copepod Paracyclopina nana. Also, activation level of mitogen-activated protein kinase (MAPK) signaling pathways along with the gene expression profile of de novo lipogenesis (DNL) pathways were addressed. As a result, BDE-47 induced oxidative stress (e.g. reactive oxygen species, ROS) mediated activation of extracellular signal-regulated kinase (ERK) and c-Jun-N-terminal kinase (JNK) signaling cascades in MAPK pathways. Activated MAPK pathways, in turn, induced signal molecules that bind to the transcription factors (TFs) responsible for lipogenesis to EcR, SREBP, ChREBP promoters. Also, the stress stimulated the conversion of saturated fatty acids (SFAs) to polyunsaturated fatty acids (PUFAs), a preparedness of the organism to adapt the observed stress, which could be correlated with the elongase and desaturase gene (e.g. ELO3, Δ5-DES, Δ9-DES) expressions, and then extended to the delayed early post-embryonic development and increased accumulation of lipid droplets in P. nana. This study will provide a better understanding of how BDE-47 effects on marine invertebrates particularly on the copepods, an important link in the marine food chain. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. Mitochondrial DNA Analyses Indicate High Diversity, Expansive Population Growth and High Genetic Connectivity of Vent Copepods (Dirivultidae) across Different Oceans.

    Science.gov (United States)

    Gollner, Sabine; Stuckas, Heiko; Kihara, Terue C; Laurent, Stefan; Kodami, Sahar; Martinez Arbizu, Pedro

    2016-01-01

    Communities in spatially fragmented deep-sea hydrothermal vents rich in polymetallic sulfides could soon face major disturbance events due to deep-sea mineral mining, such that unraveling patterns of gene flow between hydrothermal vent populations will be an important step in the development of conservation policies. Indeed, the time required by deep-sea populations to recover following habitat perturbations depends both on the direction of gene flow and the number of migrants available for re-colonization after disturbance. In this study we compare nine dirivultid copepod species across various geological settings. We analyze partial nucleotide sequences of the mtCOI gene and use divergence estimates (FST) and haplotype networks to infer intraspecific population connectivity between vent sites. Furthermore, we evaluate contrasting scenarios of demographic population expansion/decline versus constant population size (using, for example, Tajima's D). Our results indicate high diversity, population expansion and high connectivity of all copepod populations in all oceans. For example, haplotype diversity values range from 0.89 to 1 and FST values range from 0.001 to 0.11 for Stygiopontius species from the Central Indian Ridge, Mid Atlantic Ridge, East Pacific Rise, and Eastern Lau Spreading Center. We suggest that great abundance and high site occupancy by these species favor high genetic diversity. Two scenarios both showed similarly high connectivity: fast spreading centers with little distance between vent fields and slow spreading centers with greater distance between fields. This unexpected result may be due to some distinct frequency of natural disturbance events, or to aspects of individual life histories that affect realized rates of dispersal. However, our statistical performance analyses showed that at least 100 genomic regions should be sequenced to ensure accurate estimates of migration rate. Our demography parameters demonstrate that dirivultid

  2. 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

    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...

  3. Isolation of infectious hematopoietic necrosis virus from a leech (Piscicola salmositica) and a copepod (Salmincola sp.), ectoparasites of sockeye salmon Oncorhynchus nerka

    Science.gov (United States)

    Mulcahy, Daniel M.; Klaybor, D.; Batts, W.N.

    1990-01-01

    Infectious haematopoietic necrosis (IHN) virus was isolated from freshwater leeches Piscicola salmositica and copepods Salmincola sp. removed from the gills of spawning sockeye salmon, Oncorhynchus nerka. This is the first report of the isolation of IHN virus from an animal other than salmonid fishes. High levels of IHN virus were also found in leeches taken from the bottom gravel of the spawning area. The prevalence of IHN virus in samples of individual leeches was as high as 100% and the virus was isolated from 95% of pooled samples of copepod and 1.5 × 108 pfu/g in the leech. The level of virus in leeches removed from fish gills was sometimes higher than the level of virus in the gill tissue itself. Virus persisted for at least 16 d in leeches held in the laboratory without feeding. Transmission of IHN virus by leeches probably increases the infection rate of spawning sockeye salmon.

  4. The efficiency of a new hydrodynamic cavitation pilot system on Artemia salina cysts and natural population of copepods and bacteria under controlled mesocosm conditions.

    Science.gov (United States)

    Cvetković, Martina; Grego, Mateja; Turk, Valentina

    2016-04-15

    A study of the efficiency of hydrodynamic cavitation and separation was carried out to evaluate an innovative, environmentally safe and acceptable system for ballast water treatment for reducing the risk of introducing non-native species worldwide. Mesocosm experiments were performed to assess the morphological changes and viability of zooplankton (copepods), Artemia salina cysts, and the growth potential of marine bacteria after the hydrodynamic cavitation treatment with a different number of cycles. Our preliminary results confirmed the significant efficiency of the treatment since more than 98% of the copepods and A. salina cysts were damaged, in comparison with the initial population. The efficiency increased with the number of the hydrodynamic cavitation cycles, or in combination with a separation technique for cysts. There was also a significant decrease in bacterial abundance and growth rate, compared to the initial number and growth potential. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. Harpacticoid copepods-their symbiotic associations and biogenic substrata: a review.

    Science.gov (United States)

    Huys, Rony

    2016-10-11

    Members of the order Harpacticoida are primarily free-living and benthic but some lineages have adopted alternative modes of life which involve a major habitat shift or dependence on a host. Since the first discovery of a harpacticoid associated with an invertebrate host about 150 years ago, a total of 172 species, representing 84 genera and 17 families, have been shown to live in symbiotic partnership with other organisms. The steady addition of new taxa during the last 35 years testifies to the widespread and previously underestimated occurrence of symbiosis in the group. Harpacticoids have entered into associations with Cyanobacteria, Protozoa, macroalgae, grasses, fish hosts, marine tetrapods (including whales, sea turtles and manatees) and at least eleven invertebrate phyla. At present, 86 independent colonizations of marine and freshwater host organisms can be identified but this number is a minimum estimate and is expected to increase as certain host groups will be more properly sampled. In contrast to the Cyclopoida and Siphonostomatoida, which have been extremely successful in developing associations with cnidarians, sponges, echinoderms and ascidiaceans, members of the Harpacticoida have a marked predilection for crustacean hosts. Except for a few species that can be classified as genuine parasites, the precise nature of the relationship between most associated harpacticoids and their hosts has yet to be elucidated but can probably be defined as commensalistic, where the benefit to the copepod may be nutritional or protective. Most are ectosymbiotic but some live as endocommensals in microhabitats which provide considerable protection from predation. The success of symbiotic harpacticoids in freshwater is limited with the few species known to be associated with freshwater hosts typically representing isolated forays into a symbiotic lifestyle from an otherwise free-living lineage. The scattered literature on symbiotic harpacticoids is compiled and

  6. A non-diatom plankton bloom controlled by copepod grazing and amphipod predation: Preliminary results from the LOHAFEX iron-fertilisation experiment

    Digital Repository Service at National Institute of Oceanography (India)

    Mazzocchi, M.G.; Gonzalez, H.E.; Vandromme, P.; Borrione, I.; deAlcala, M.R.; Gauns, M.; Assmy, P.; Fuchs, B.; Klaas, C.; Martin, P.; Montresor, M.; Ramaiah, N.; Naqvi, S.W.A.; Smetacek, V.

    INTERNATIONAL NEWSLETTER OCTOBER 2009 3 GLOBEC INTERNATIONAL NEWSLETTER OCTOBER 2009 A non-diatom plankton bloom controlled by copepod grazing and amphipod predation: Preliminary results from the LOHAFEX iron-fertilisation experiment Maria Grazia Mazzocchi 1... and corroborated with counts made with an inverted microscope as high as > 15 x 10 6 cells L - 1 . A significant fraction of the larger flagellates (~ 5 µm) were Phaeocystis solitary cells that started making numerous colonies in the second week, so we were...

  7. A brominated flame retardant 2,2',4,4' tetrabrominated diphenyl ether (BDE-47) leads to lipogenesis in the copepod Tigriopus japonicus.

    Science.gov (United States)

    Lee, Min-Chul; Han, Jeonghoon; Lee, Seung-Hwi; Kim, Duck-Hyun; Kang, Hye-Min; Won, Eun-Ji; Hwang, Dae-Sik; Park, Jun Chul; Om, Ae-Son; Lee, Jae-Seong

    2016-09-01

    De novo lipogenesis (DNL) is a fatty acid synthesis process that requires several genes, including sterol regulatory element binding protein (SREBP), ATP-citrate lyase (ACLY), and acetyl-CoA carboxylase (ACC). DNL up-regulation is able to induce fat accumulation through an increase in fatty acids. To investigate the relationship between DNL up-regulation and the accumulation of fatty acids and lipid droplets in response to 2,2',4,4' tetrabrominated diphenyl ether (BDE-47), we examined DNL in the copepod Tigriopus japonicus. Transcription levels of DNL-related genes were increased after exposure to 2.5μg/L BDE-47 for 24h. After exposure to 2.5μg/L BDE-47, palmitic acid was significantly increased (Plipogenesis inhibitor), indicating that BDE-47 exposure is closely associated with an increase in fatty acids in this copepod. This study provides a better understanding of the effects of BDE-47 on DNL in copepods. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. A new species of the rare endoparasitic copepod Entobius (Copepoda: Entobiidae) from Mexico with a key to the species of the genus.

    Science.gov (United States)

    Suárez-Morales, Eduardo; Carrera-Parra, Luis F

    2012-09-01

    Abstract: In a study of the benthic polychaete fauna of the southern Gulf of Mexico and the Caribbean Sea, several specimens of the terebellid polychaete Scionides reticulata (Ehlers) were found to host endoparasitic copepods that represent an undescribed species of the rare cyclopoid genus Entobius Dogiel, 1948. The new species, E. scionides sp. n., can be distinguished from its congeners by a combination of characters including a genital region without constrictions, three-segmented antennules, a reduced antenna with a blunt terminal process, reduced ornamentation of endopods of legs 1-4 and its relatively small size (2.3-2.7 mm). It is the smallest species of the genus. Comments on immature females are also provided, but males of this species remain unknown. It has a high prevalence (53%) in populations of the terebellid S. reticulata in the southern Gulf of Mexico, but it is absent from the Caribbean. This is the first occurrence of this copepod genus in the Americas. The finding of the new species of Entobius in S. reticulata confirms the strict specificity of most members of the genus and expands the host range of this copepod genus. A key for the identification of the species of Entobius is provided.

  9. Tidal influence on the distribution of hydrophobic organic contaminants in the Seine Estuary and biomarker responses on the copepod Eurytemora affinis

    Energy Technology Data Exchange (ETDEWEB)

    Cailleaud, K. [Universite Bordeaux 1, CNRS, ISM-LPTC-UMR 5255, Laboratory of Physico- and Toxico-Chemistry, 351 Cours de la Liberation, 33405 Talence (France) and Universite des Sciences et Technologies de Lille - Lille 1, Laboratoire d' Oceanologie et de Geosciences, UMR CNRS 8187 LOG, Station Marine de Wimereux, 28 Avenue Foch, 62930 Wimereux (France) and Faculte des Sciences et Techniques du Havre, LEMA-UPRES EA3222, Laboratoire d' Ecotoxicologie-Milieux Aquatiques, GDR IMOPHYS, 25 rue Philippe Lebon, 76058 Le Havre (France); Forget-Leray, J. [Faculte des Sciences et Techniques du Havre, LEMA-UPRES EA3222, Laboratoire d' Ecotoxicologie-Milieux Aquatiques, GDR IMOPHYS, 25 rue Philippe Lebon, 76058 Le Havre (France); Peluhet, L.; LeMenach, K. [Universite Bordeaux 1, CNRS, ISM-LPTC-UMR 5255, Laboratory of Physico- and Toxico-Chemistry, 351 Cours de la Liberation, 33405 Talence (France); Souissi, S. [Universite des Sciences et Technologies de Lille - Lille 1, Laboratoire d' Oceanologie et de Geosciences, UMR CNRS 8187 LOG, Station Marine de Wimereux, 28 Avenue Foch, 62930 Wimereux (France); Budzinski, H. [Universite Bordeaux 1, CNRS, ISM-LPTC-UMR 5255, Laboratory of Physico- and Toxico-Chemistry, 351 Cours de la Liberation, 33405 Talence (France)], E-mail: h.budzinski@ism.u-bordeaux1.fr

    2009-01-15

    To elucidate tidally related variations of hydrophobic organic contaminant (HOC) bioavailability and the impact of these contaminants on estuarine ecosystems, both PCB and PAH concentrations were investigated in the dissolved phase and in the suspended particulate material (SPM) of the Seine Estuary. Both PAH and PCB highest levels were observed in surface and bottom water when SPM remobilizations were maximum, in relation to higher speed currents. In parallel, acetylcholinesterase (AChE) and glutathione-S-transferase (GST) activities were investigated in the copepod Eurytemora affinis. Significant decreasing AChE levels were measured during the tidal cycle and between surface and bottom copepods related to salinity and to HOC concentration variations. Significant increasing GST levels were also observed when HOC concentrations in the water column were the highest. This study underlined the need to standardize sampling procedures for biomonitoring studies in order to avoid interfering factors that could modify biomarker responses to chemical exposure. - Variations of contamination of E. affinis and enzymatic responses have been studied over a tide cycle in view to improve the use of this copepod for biomonitoring.

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

    Science.gov (United States)

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

    2015-04-01

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

  11. Detailed surface morphology of the 'lobster louse' copepod, Nicothoë astaci, a haematophagous gill parasite of the European lobster, Homarus gammarus.

    Science.gov (United States)

    Davies, Charlotte E; Thomas, Gethin R; Maffeis, Thierry G G; Wootton, Emma C; Penny, Mark W; Rowley, Andrew F

    2014-10-01

    The ectoparasitic copepod, Nicothoë astaci (the 'lobster louse'), infests the gills of the European lobster, Homarus gammarus. There have been limited studies on this haematophagous species; therefore knowledge of this parasite is rudimentary. The current study examines the surface morphology of this parasitic copepod, detached from the host, concentrating on adaptations of the suctorial mouthpart, the oral disc. Cryo-scanning electron microscopy revealed structural adaptations that facilitate attachment of these parasites to the gill filaments of their lobster host. The aperture of the feeding channel, through which host haemolymph is drawn, is only ca. 5μm in diameter. The edge of the oral disc is lined with numerous setae, whilst the surface of the disc is covered with large numbers of small (<1μm in diameter) teeth-like structures, which presumably pierce through, and grip, the cuticle lining of the host's gill. Overall, these structures are thought to provide a 'vacuum seal' to assist in pumping of blood, via peristalsis, into the alimentary canal of the copepod host. Copyright © 2014 Elsevier Inc. All rights reserved.

  12. Eucalanoid copepod metabolic rates in the oxygen minimum zone of the eastern tropical north Pacific: Effects of oxygen and temperature

    Science.gov (United States)

    Cass, Christine J.; Daly, Kendra L.

    2014-12-01

    The eastern tropical north Pacific Ocean (ETNP) contains one of the world's most severe oxygen minimum zones (OMZs), where oxygen concentrations are less than 2 μmol kg-1. OMZs cause habitat compression, whereby species intolerant of low oxygen are restricted to near-surface oxygenated waters. Copepods belonging to the family Eucalanidae are dominant zooplankters in this region and inhabit a variety of vertical habitats within the OMZ. The purpose of this study was to compare the metabolic responses of three species of eucalanoid copepods, Eucalanus inermis, Rhincalanus rostrifrons, and Subeucalanus subtenuis, to changes in temperature and environmental oxygen concentrations. Oxygen consumption and urea, ammonium, and phosphate excretion rates were measured via end-point experiments at three temperatures (10, 17, and 23 °C) and two oxygen concentrations (100% and 15% air saturation). S. subtenuis, which occurred primarily in the upper 50 m of the water column at our study site, inhabiting well-oxygenated to upper oxycline conditions, had the highest metabolic rates per unit weight, while E. inermis, which was found throughout the water column to about 600 m depth in low oxygen waters, typically had the lowest metabolic rates. Rates for R. rostrifrons (found primarily between 200 and 300 m depth) were intermediate between the other two species and more variable. Metabolic ratios suggested that R. rostrifrons relied more heavily on lipids to fuel metabolism than the other two species. S. subtenuis was the only species that demonstrated a decrease in oxygen consumption rates (at intermediate 17 °C temperature treatment) when environmental oxygen concentrations were lowered. The percentage of total measured nitrogen excreted as urea (% urea-N), as well as overall urea excretion rates, responded in a complex manner to changes in temperature and oxygen concentration. R. rostrifrons and E. inermis excreted a significantly higher % of urea-N in low oxygen treatments at

  13. Gamma rays induce DNA damage and oxidative stress associated with impaired growth and reproduction in the copepod Tigriopus japonicus

    Energy Technology Data Exchange (ETDEWEB)

    Han, Jeonghoon; Won, Eun-Ji; Lee, Bo-Young [Department of Biological Sciences, College of Science, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Hwang, Un-Ki [Marine Ecological Risk Assessment Center, West Sea Fisheries Research Institute, National Fisheries Research and Development Institute, Incheon 400-420 (Korea, Republic of); Kim, Il-Chan; Yim, Joung Han [Division of Life Sciences, Korea Polar Research Institute, Incheon 406-840 (Korea, Republic of); Leung, Kenneth Mei Yee [School of Biological Sciences and the Swire Institute of Marine Science, The University of Hong Kong, Pokfulam Road, Hong Kong (China); Lee, Yong Sung [Graduate School of Biomedical Science and Engineering, Hanyang University, Seoul 133-791 (Korea, Republic of); Lee, Jae-Seong, E-mail: jslee2@skku.edu [Department of Biological Sciences, College of Science, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of)

    2014-07-01

    Highlights: • Mortality rate was significantly increased in response to gamma radiation. • A dose-dependent reduction in fecundity of ovigerous females. • Growth retardation, particularly at the nauplius stage. • Upon gamma radiation, T. japonicus showed an increased ROS levels. • Antioxidant genes and Hsps genes were upregulated at sublethal doses. - Abstract: Nuclear radioisotope accidents are potentially ecologically devastating due to their impact on marine organisms. To examine the effects of exposure of a marine organism to radioisotopes, we irradiated the intertidal copepod Tigriopus japonicus with several doses of gamma radiation and analyzed the effects on mortality, fecundity, and molting by assessing antioxidant enzyme activities and gene expression patterns. No mortality was observed at 96 h, even in response to exposure to a high dose (800 Gy) of radiation, but mortality rate was significantly increased 120 h (5 days) after exposure to 600 or 800 Gy gamma ray radiation. We observed a dose-dependent reduction in fecundity of ovigerous females; even the group irradiated with 50 Gy showed a significant reduction in fecundity, suggesting that gamma rays are likely to have a population level effect. In addition, we observed growth retardation, particularly at the nauplius stage, in individuals after gamma irradiation. In fact, nauplii irradiated with more than 200 Gy, though able to molt to copepodite stage 1, did not develop into adults. Upon gamma radiation, T. japonicus showed a dose-dependent increase in reactive oxygen species (ROS) levels, the activities of several antioxidant enzymes, and expression of double-stranded DNA break damage genes (e.g. DNA-PK, Ku70, Ku80). At a low level (sub-lethal dose) of gamma irradiation, we found dose-dependent upregulation of p53, implying cellular damage in T. japonicus in response to sub-lethal doses of gamma irradiation, suggesting that T. japonicus is not susceptible to sub-lethal doses of gamma

  14. Gamma rays induce DNA damage and oxidative stress associated with impaired growth and reproduction in the copepod Tigriopus japonicus.

    Science.gov (United States)

    Han, Jeonghoon; Won, Eun-Ji; Lee, Bo-Young; Hwang, Un-Ki; Kim, Il-Chan; Yim, Joung Han; Leung, Kenneth Mei Yee; Lee, Yong Sung; Lee, Jae-Seong

    2014-07-01

    Nuclear radioisotope accidents are potentially ecologically devastating due to their impact on marine organisms. To examine the effects of exposure of a marine organism to radioisotopes, we irradiated the intertidal copepod Tigriopus japonicus with several doses of gamma radiation and analyzed the effects on mortality, fecundity, and molting by assessing antioxidant enzyme activities and gene expression patterns. No mortality was observed at 96h, even in response to exposure to a high dose (800Gy) of radiation, but mortality rate was significantly increased 120h (5 days) after exposure to 600 or 800Gy gamma ray radiation. We observed a dose-dependent reduction in fecundity of ovigerous females; even the group irradiated with 50Gy showed a significant reduction in fecundity, suggesting that gamma rays are likely to have a population level effect. In addition, we observed growth retardation, particularly at the nauplius stage, in individuals after gamma irradiation. In fact, nauplii irradiated with more than 200Gy, though able to molt to copepodite stage 1, did not develop into adults. Upon gamma radiation, T. japonicus showed a dose-dependent increase in reactive oxygen species (ROS) levels, the activities of several antioxidant enzymes, and expression of double-stranded DNA break damage genes (e.g. DNA-PK, Ku70, Ku80). At a low level (sub-lethal dose) of gamma irradiation, we found dose-dependent upregulation of p53, implying cellular damage in T. japonicus in response to sub-lethal doses of gamma irradiation, suggesting that T. japonicus is not susceptible to sub-lethal doses of gamma irradiation. Additionally, antioxidant genes, phase II enzyme (e.g. GSTs), and cellular chaperone genes (e.g. Hsps) that are involved in cellular defense mechanisms also showed the same expression patterns for sublethal doses of gamma irradiation (50-200Gy). These findings indicate that sublethal doses of gamma radiation can induce oxidative stress-mediated DNA damage and increase

  15. Golfingicola abyssalis gen. et sp. nov., a new endoparasitic copepod (Crustacea) in a sipunculan from abyssal depths of the Northwest Pacific Ocean

    Science.gov (United States)

    Schwabe, Enrico; Maiorova, Anastassya

    2015-01-01

    Marine copepods, which inhabit the entire water column down to the seafloor, are key contributors to the food web, mainly providing a food source for many organisms in the form of zooplankton. Furthermore, they also play an important ecological role as associates or even parasites with various degrees of harm to their hosts. Copepods are found in almost all habitats and can be associated with virtually every metazoan group. A female and four males of a new endoparasitic copepod genus and species (Golfingicola abyssalis) are described from the trunk celom of the sipunculan Golfingia muricaudata (Southern, 1913), collected from the abyssal depths of the Northwest Pacific Ocean near the Kuril-Kamchatka Trench. This sipunculan species is a typical deep sea representative of the northwestern Pacific region, occurring in the Bering Sea and the abyssal regions east of the Kuril Island chain. Despite numerous records of this species, a copepod association has not been reported prior to this paper. The new parasitic copepod species is tentatively placed in the Akessonia group given its endoparasitic behavior in Sipuncula, the elongated shape, the enlarged egg strings, and the presence of subchelate antenna, as well as lateral processes in males. Golfingicola abyssalis, however, shows some peculiarities that clearly differentiate it from the remaining endoparasites in Sipuncula. As the first abyssal endoparasite in Sipuncula, the species is characterized by the complete lack of any processes in females, the presence of a mandible in females, a weakly defined prosome-urosome boundary in females, the presence of a mouth in males, the free living behavior of males, a distinctly reduced number of trunk processes in males, as well as a more modified male antenna, displaying an endopodite and a highly modified setal element. A detailed review on the morphological characters of the four species currently grouped in the Akessonia group, and systematic and biogeographic information

  16. Seasonal dynamics of zooplankton in Columbia–Snake River reservoirs,with special emphasis on the invasive copepod Pseudodiaptomus forbesi

    Science.gov (United States)

    Emerson, Joshua E.; Bollens, Stephen M.; Counihan, Timothy D.

    2015-01-01

    The Asian copepod Pseudodiaptomus forbesi has recently become established in the Columbia River. However, little is known about its ecology and effects on invaded ecosystems. We undertook a 2-year (July 2009 to June 2011) field study of the mesozooplankton in four reservoirs in the Columbia and Snake Rivers, with emphasis on the relation of the seasonal variation in distribution and abundance of P. forbesi to environmental variables. Pseudodiaptomus forbesi was abundant in three reservoirs; the zooplankton community of the fourth reservoir contained no known non-indigenous taxa. The composition and seasonal succession of zooplankton were similar in the three invaded reservoirs: a bloom of rotifers occurred in spring, native cyclopoid and cladoceran species peaked in abundance in summer, and P. forbesi was most abundant in late summer and autumn. In the uninvaded reservoir, total zooplankton abundance was very low year-round. Multivariate ordination indicated that temperature and dissolved oxygen were strongly associated with zooplankton community structure, with P. forbesi appearing to exhibit a single generation per year . The broad distribution and high abundance of P. forbesi in the Columbia–Snake River System could result in ecosystem level effects in areas intensively managed to improve conditions for salmon and other commercially and culturally important fish species. 

  17. Gamma radiation induces growth retardation, impaired egg production, and oxidative stress in the marine copepod Paracyclopina nana

    Energy Technology Data Exchange (ETDEWEB)

    Won, Eun-Ji; Lee, Jae-Seong, E-mail: jslee2@skku.edu

    2014-05-01

    Highlights: • Mortality was increased with a dose dependent manner in ovigerous females of Paracyclopina nana. • Developmental impairments were observed in gamma irradiated nauplii. • Ovigerous females exposed to more than 50 Gy could not have normal two bilateral egg sacs. • Oxidative levels increased with antioxidant enzyme activities in the gamma irradiated P. nana. • The molecular indices (antioxidant enzymes and heat shock protein) were also increased. - Abstract: Accidental nuclear radioisotope release into the ocean from nuclear power plants is of concern due to ecological and health risks. In this study, we used the marine copepod Paracyclopina nana to examine the effects of radioisotopes on marine organisms upon gamma radiation, and to measure the effects on growth and fecundity, which affect population and community structure. Upon gamma radiation, mortality (LD50 – 96 h = 172 Gy) in P. nana was significantly increased in a dose-dependent manner in ovigerous P. nana females. For developmental impairment of gamma-irradiated nauplii, we observed growth retardation; in over 30 Gy-irradiated groups, offspring did not grow to adults. Particularly, over 50 Gy-irradiated ovigerous P. nana females did not have normal bilateral egg sacs, and their offspring did not develop normally to adulthood. Additionally, at over 30 Gy, we found dose-dependent increases in oxidative levels with elevated antioxidant enzyme activities and DNA repair activities. These findings indicate that gamma radiation can induce oxidative stress and DNA damage with growth retardation and impaired reproduction.

  18. Developmental retardation, reduced fecundity, and modulated expression of the defensome in the intertidal copepod Tigriopus japonicus exposed to BDE-47 and PFOS

    Energy Technology Data Exchange (ETDEWEB)

    Han, Jeonghoon; Won, Eun-Ji; Lee, Min-Chul [Department of Biological Science, College of Science, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Seo, Jung Soo [Pathology Team, National Fisheries Research & Development Institute, Busan 619-902 (Korea, Republic of); Lee, Su-Jae [Department of Life Science, College of Natural Sciences, Hanyang University, Seoul 133-791 (Korea, Republic of); Lee, Jae-Seong, E-mail: jslee2@skku.edu [Department of Biological Science, College of Science, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of)

    2015-08-15

    Highlights: • The repercussions of BDE-47 and PFOS were occurred on development and fecundity. • BDE-47 and PFOS can induce oxidative stress through the generation of ROS. • The expression of defensome was changed in response to BDE-47 and PFOS. • ROS-induced DNA damage in BDE-47 and PFOS exposure lead to apoptosis and DNA repair. - Abstract: 2,2′,4,4′-tetrabromodiphenyl ether (BDE-47) and perfluorooctane sulfonate (PFOS) are widely dispersed persistent organic pollutants (POPs) in the marine ecosystem. However, their toxic effects on marine organisms are still poorly understood. In this study, we investigated the effects of BDE-47 and PFOS on development and reproduction at the organismal level and reactive oxygen species (ROS) production and gene expression patterns of the defensome at the cellular level in the intertidal copepod Tigriopus japonicus. In copepods exposed to BDE-47 and PFOS, we observed developmental retardation and reduced fecundity, suggesting repercussions on in vivo endpoints through alterations to the normal molting and reproduction system of T. japonicus. BDE-47 and PFOS increased levels of ROS in T. japonicus in a concentration-dependent manner, indicating that POPs can induce oxidative stress through the generation of ROS. Additionally, transcript profiles of genes related to detoxification (e.g., CYPs), antioxidant functions (e.g., GST- sigma, catalase, MnSOD), apoptosis (e.g., p53, Rb), and cellular proliferation (e.g., PCNA) were modulated over 72 h in response to BDE-47 (120 μg/L) and PFOS (1000 μg/L). These findings indicate that BDE-47 and PFOS can induce oxidative stress-mediated DNA damage repair systems with transcriptional regulation of detoxification, antioxidant, and apoptosis-related genes, resulting in developmental retardation and reduced fecundity in the copepod T. japonicus.

  19. Producing a problem? Effects of produced water contaminants (PAHs, radium-226, barium and scale inhibitor) on the copepod Calanus finmarchicus

    Energy Technology Data Exchange (ETDEWEB)

    Kiel Jensen, Louise [Norwegian Radiation Protection Authority, Fram Centre, 9296 Tromsoe (Norway); Halvorsen, Elisabeth; Gammelsaeter Hallanger, Ingeborg [UiT The Arctic University of Norway, Department of Arctic and Marine Biology, P.O. box 6050 Langnes, 9037 Tromsoe (Norway); Tollefsen, Knut Erik; Brooks, Steven [Norwegian Institute for Water Research, Gaustadalleen 21, 0349 Oslo (Norway); Hansen, Bjoern Henrik [SINTEF Materials and Chemistry, Marine Environmental Technology, Brattoerkaia 17B, 7010 Trondheim (Norway)

    2014-07-01

    In the Barents Sea region new petroleum fields are discovered yearly and the extraction of petroleum products are expected to increase in the upcoming years. Despite enhanced technology and stricter governmental legislation, establishing the petroleum industry in the Barents Sea will introduce a new source of Naturally Occurring Radioactive Material (NORM) to the area as some discharges of produced water will be allowed. Whether the presence of produced water poses a risk to the Arctic marine life remains to be examined. We examined effects on the copepod species Calanus finmarchicus after exposure to several compounds found in produced water. A mixture of polycyclic aromatic hydrocarbons and alkyl phenols commonly found in produced water was used as a proxy of the organic fraction of the produced water (hereafter termed APW (Artificial Produced Water)). In addition, exposures were done using radium-226 (proxy for NORM), barium (proxy for metals) and a scale inhibitor (SI -4470, M-I SWACO, Schlumberger Norge AS). Short-term screening tests on a range of concentrations of all compounds were run to assess the hatchability of the eggs and early survival of the nauplii. Long-term experiments were carried out with exposure concentrations at realistic levels found in the vicinity of known discharge points. The copepod C. finmarchicus is considered a keystone species in the Barents Sea ecosystem as it represents the major pathway of energy transfer from lower to higher trophic levels. We have examined sub-lethal effects on early life stages and on adult females. The hatchability of the eggs was not affected by concentrations well above realistic environmental levels. However, the instant mortality of the hatched larvae increased with higher concentrations of barium, scale inhibitor and APW, though not with higher radium-226 concentration. When examining the long-term growth of the nauplii, we found that the survival was poor in the APW treatment, and in the barium

  20. Sensitivity of the marine benthic copepod Tisbe biminiensis (copepoda, harpacticoida to potassium dichromate and sediment particle size

    Directory of Open Access Journals (Sweden)

    Cristiane M. V. Araújo-Castro

    2009-03-01

    Full Text Available For the future use of the marine benthic copepod Tisbe biminiensis in solid-phase sediment toxicological bioassays, the present study investigated the effect of muddy sediment from the Maracaípe estuary (northeastern Brazil, sediment particle size and the reference toxicant potassium dichromate on the species. Muddy sediment from Maracaípe can be used as control sediment, since it does not interfere in the copepod life-cycle and has metal contamination levels that are unlikely to produce any detrimental biological effects on benthic invertebrates. Neither survival nor fecundity was affected by grain size, suggesting that this species can be used with any kind of sediment from muddy to sandy. The sensitivity of T. biminiensis to K2Cr2O7 in acute tests was similar to that of other organisms. The LC50 (lethal concentration to 50% of the test organisms medium values for T. biminiensis were 7.51, 4.68 and 3.19 mg L-1 for Cr in 48, 72 and 96 h, respectively. These results suggest that T. biminiensis is a promising organism for use in solid-phase sediment toxicity assessments.Visando o uso futuro do copépodo marinho bentônico Tisbe biminiensis em bioensaios toxicológicos de sedimentos na fase sólida, o presente estudo investigou o efeito do sedimento lamoso do estuário de Maracaípe (Nordeste do Brasil. Foram considerados a granolometria e o tóxico de referência dicromato de potássio sobre a espécie. O sedimento lamoso de Maracaípe pode ser usado como controle, uma vez que não interfere no ciclo de vida do copépodo e possui níveis de contaminação de metais que não causariam efeitos biológicos em invertebrados bentônicos. Nem a sobrevivência ou fecundidade foi afetada pelo tamanho do grão, sugerindo que esta espécie pode ser usada com qualquer tipo de sedimento, de lama a areia. A sensibilidade de T. biminiensis ao K2Cr2O7 em testes agudos foi similar a de outros organismos. Os valores de CL50 (concentração letal a 50% dos

  1. Phylogeography of Calanus helgolandicus and the Black Sea copepod Calanus euxinus, with notes on Pseudocalanus elongatus (Copepoda, Calanoida)

    Science.gov (United States)

    Unal, Ebru; Frost, Bruce W.; Armbrust, Virginia; Kideys, Ahmet E.

    2006-08-01

    Calanus helgolandicus is a widespread epipelagic copepod species whose geographical range extends from the temperate Atlantic Ocean to the northern Mediterranean Sea. Calanus euxinus, recently designated as a distinct species though closely related to C. helgolandicus, occurs in the Black Sea. Very subtle morphological differences distinguish the two species. Pseudocalanus elongatus has a similar geographic range including North Atlantic Ocean, Mediterranean Sea and the Black Sea. In this study, population genetic variation of C. helgolandicus, C. euxinus and P. elongatus was investigated using DNA sequence variation of 540 base pair ( Calanus spp.) and 575 base pair ( P. elongatus) regions of mitochondrial cytochrome oxidase I (mtCOI) gene. C. helgolandicus was collected from the English Channel, the Adriatic Sea, and C. euxinus was collected from various regions of the Black Sea. P. elongatus was collected from the English Channel and the Black Sea. Intraspecific differentiation in mtCOI was <1% for all species; mtCOI sequence variation between C. helgolandicus and C. euxinus was <0.5%. The absence of substantial genetic differentiation between C. helgolandicus and C. euxinus is particularly striking in comparison to other close species pairs in these genera. Statistically significant haplotype frequency differences were determined for different locations of the Black Sea, English Channel, and Adriatic Sea Calanus populations ( χ2=3.94, P<0.0001). The haplotype diversity was high for all species: C. euxinus ( h=0.92), C. helgolandicus ( h⩽0.80), P. elongatus ( h⩽0.60). No haplotype sharing was reported for different locations of P. elongatus, whereas the presence of haplotype sharing between C. helgolandicus and C. euxinus was remarkable. The size distribution in terms of prosome length measurements was found to be region-specific. The lack of phylogenetic differentiation between the Calanus species pair may suggest ancestral polymorphisms. The morphological

  2. Genomic characterization and phylogenetic position of two new species in Rhabdoviridae infecting the parasitic copepod, salmon louse (Lepeophtheirus salmonis.

    Directory of Open Access Journals (Sweden)

    Arnfinn Lodden Økland

    Full Text Available Several new viruses have emerged during farming of salmonids in the North Atlantic causing large losses to the industry. Still the blood feeding copepod parasite, Lepeophtheirus salmonis, remains the major challenge for the industry. Histological examinations of this parasite have revealed the presence of several virus-like particles including some with morphologies similar to rhabdoviruses. This study is the first description of the genome and target tissues of two new species of rhabdoviruses associated with pathology in the salmon louse. Salmon lice were collected at different Atlantic salmon (Salmo salar farming sites on the west coast of Norway and prepared for histology, transmission electron microscopy and Illumina sequencing of the complete RNA extracted from these lice. The nearly complete genomes, around 11,600 nucleotides encoding the five typical rhabdovirus genes N, P, M, G and L, of two new species were obtained. The genome sequences, the putative protein sequences, and predicted transcription strategies for the two viruses are presented. Phylogenetic analyses of the putative N and L proteins indicated closest similarity to the Sigmavirus/Dimarhabdoviruses cluster, however, the genomes of both new viruses are significantly diverged with no close affinity to any of the existing rhabdovirus genera. In situ hybridization, targeting the N protein genes, showed that the viruses were present in the same glandular tissues as the observed rhabdovirus-like particles. Both viruses were present in all developmental stages of the salmon louse, and associated with necrosis of glandular tissues in adult lice. As the two viruses were present in eggs and free-living planktonic stages of the salmon louse vertical, transmission of the viruses are suggested. The tissues of the lice host, Atlantic salmon, with the exception of skin at the attachment site for the salmon louse chalimi stages, were negative for these two viruses.

  3. Cymbopogon citratus-synthesized gold nanoparticles boost the predation efficiency of copepod Mesocyclops aspericornis against malaria and dengue mosquitoes.

    Science.gov (United States)

    Murugan, Kadarkarai; Benelli, Giovanni; Panneerselvam, Chellasamy; Subramaniam, Jayapal; Jeyalalitha, Tirupathi; Dinesh, Devakumar; Nicoletti, Marcello; Hwang, Jiang-Shiou; Suresh, Udaiyan; Madhiyazhagan, Pari

    2015-06-01

    Plant-borne compounds can be employed to synthesize mosquitocidal nanoparticles that are effective at low doses. However, how they affect the activity of mosquito predators in the aquatic environment is unknown. In this study, we synthesized gold nanoparticles (AuN) using the leaf extract of Cymbopogon citratus, which acted as a reducing and capping agent. AuN were characterized by a variety of biophysical methods and sorted for size in order to confirm structural integrity. C. citratus extract and biosynthesized AuN were tested against larvae and pupae of the malaria vector Anopheles stephensi and the dengue vector Aedes aegypti. LC₅₀ of C. citratus extract ranged from 219.32 ppm to 471.36 ppm. LC₅₀ of AuN ranged from 18.80 ppm to 41.52 ppm. In laboratory, the predatory efficiency of the cyclopoid crustacean Mesocyclops aspericornis against A. stephensi larvae was 26.8% (larva I) and 17% (larva II), while against A. aegypti was 56% (I) and 35.1% (II). Predation against late-instar larvae was minimal. In AuN-contaminated environment,predation efficiency against A. stephensi was 45.6% (I) and 26.7% (II), while against A. aegypti was 77.3% (I) and 51.6% (II). Overall, low doses of AuN may help to boost the control of Anopheles and Aedes larval populations in copepod-based control programs. Copyright © 2015 Elsevier Inc. All rights reserved.

  4. Molecular evolution of versatile derivatives from a GFP-like protein in the marine copepod Chiridius poppei.

    Directory of Open Access Journals (Sweden)

    Akihisa Shimizu

    Full Text Available Fluorescent proteins are now indispensable tools in molecular research. They have also been adapted for a wide variety of uses in cases involving creative applications, including textiles, aquarium fish, and ornamental plants. Our colleagues have previously cloned a yellow GFP-like protein derived from the marine copepod Chiridius poppei (YGFP, and moreover, succeeded in generating transgenic flowers with clearly visible fluorescence, without the need for high-sensitivity imaging equipment. However, due to the low Stokes shift of YGFP (10 nm, it is difficult to separate emitted light of a labeled object from the light used for excitation; hence, limitations for various applications remain. In this study, which was aimed at developing YGFP mutants with increased Stokes shifts, we conducted stepwise molecular evolution experiments on YGFP by screening random mutations at three key amino acids, based on their fluorescent characteristics and structural stabilities, followed by optimization of their fluorescence output by DNA shuffling of the entire coding sequence. We successfully identified an eYGFPuv that had an excitation maximum in UV wavelengths and a 24-fold increase in fluorescence intensity compared to the previously reported YGFP mutant (H52D. In addition, eYGFPuv exhibited almost 9-fold higher fluorescence intensity compared to the commercially available GFPuv when expressed in human colon carcinoma HCT116 cells and without any differences in cytotoxicity. Thus, this novel mutant with the desirable characteristics of bright fluorescence, long Stokes shift, and low cytotoxity, may be particularly well suited to a variety of molecular and biological applications.

  5. Ultraviolet B radiation induces impaired lifecycle traits and modulates expression of cytochrome P450 (CYP) genes in the copepod Tigriopus japonicus

    Energy Technology Data Exchange (ETDEWEB)

    Puthumana, Jayesh; Lee, Min-Chul; Park, Jun Chul; Kim, Hui-Su; Hwang, Dae-Sik; Han, Jeonghoon, E-mail: jeonghoon@skku.edu; Lee, Jae-Seong, E-mail: jslee2@skku.edu

    2017-03-15

    Highlights: • Impaired effects of UV-B on the copepod Tigriopus japonicus were examined. • Modulation of entire CYP genes were analyzed in response to UV-B. • CYP inhibitor (PBO) confirmed the role of CYP in UV-B induced mortality. • Low-dose UV-B found induce developmental delays, and higher doses cause reproductive impairments. • Study predicted the mechanistic effects of UV-B in copepods through the AhR-mediated up-regulation of CYP genes. - Abstract: To evaluate the effects of ultraviolet B (UV-B) radiation at the developmental, reproductive, and molecular levels in aquatic invertebrates, we measured UV-B-induced acute toxicity, impairments in developmental and reproductive traits, and UV-B interaction with the entire family of cytochrome P450 (CYP) genes in the intertidal benthic copepod Tigriopus japonicus. We found a significant, dose-dependent reduction (P < 0.05) in the survival of T. japonicus that began as a developmental delay and decreased fecundity. The 48 h LD10 and LD50 were 1.35 and 1.84 kJ/m{sup 2}, and the CYP inhibitor (PBO) elevated mortality, confirming the involvement of CYP genes in UV-B induced toxicity. Low-dose UV-B (1.5 kJ/m{sup 2}) induced developmental delays, and higher doses (6–18 kJ/m{sup 2}) caused reproductive impairments in ovigerous females. The significant up-regulation of CYP genes belonging to clans 2/3/MT/4/20 in T. japonicus exposed to UV-B (12 kJ/m{sup 2}) confirmed molecular interaction between UV-B and CYP genes. Moreover, orphan CYPs, such as CYP20A1, provide good insight on the deorphanization of invertebrate CYPs. Overall, these results demonstrate the involvement of UV-B radiation in the expression of all the CYP genes in T. japonicus and their susceptibility to UV-B radiation. This will provide a better understanding of the mechanistic effects of UV-B in copepods through the predicted AhR-mediated up-regulation of CYP genes.

  6. Effects of cold selective breeding on the body length, fatty acid content, and productivity of the tropical copepod Apocyclops royi (Cyclopoida, Copepoda)

    DEFF Research Database (Denmark)

    Pan, Yen-Ju; Souissi, Anissa; Sadovskaya, Irina

    2017-01-01

    strain) temperature for 10 months, corresponding to ~40 and 15 generations, respectively. After temperature acclimation, multigenerational observations were made to investigate the effects of cold selection on the copepods. Differences in female and nauplius lengths, nauplius production, and fatty acid...... and omega 6 and omega 3 polyunsaturated fatty acid contents were higher in the selective strain than in the control strain; however, the fatty acid content gradually decreased in subsequent generations. This paper reports the effects of temperature acclimation on the morphological and physiological traits...

  7. A new species of parasitic copepod, Sarcotretes umitakae sp. n. (Siphonostomatoida, Pennellidae, on the rattail (Actinopterygii, Macrouridae from the East China Sea, Japan

    Directory of Open Access Journals (Sweden)

    Daisuke Uyeno

    2012-11-01

    Full Text Available A new species of copepod, Sarcotretes umitakae sp. n., of the siphonostomatoid family Pennellidae is described based on female specimens from the rattail Coelorinchus jordani Smith and Pope (Actinopterygii: Gadiformes: Macrouridae caught in the East China Sea. This species is characterized by exhibiting the following characters: the large proboscis projects strongly; the head bears paired lateral processes which are bulbous and taper into a slender horn; the twisting neck is significantly longer than the trunk; and the trunk bears an anterior constriction with a reduced abdomen.

  8. Community structure and estimated contribution of primary consumers (Nematodes and Copepods) of decomposing plant litter (Juncus roemerianus and Rhizophora mangle) in South Florida

    Energy Technology Data Exchange (ETDEWEB)

    Fell, J.W.; Cefalu, R.

    1984-01-01

    The paper discusses the meiofauna associated with decomposing leaf litter from two species of coastal marshland plants: the black needle rush, Juncus roemerianus and the red mangrove, Rhizophora mangle. The following aspects were investigated: (1) types of meiofauna present, especially nematodes; (2) changes in meiofaunal community structures with regard to season, station location, and type of plant litter; (3) amount of nematode and copepod biomass present on the decomposing plant litter; and (4) an estimation of the possible role of the nematodes in the decomposition process. 28 references, 5 figures, 9 tables. (ACR)

  9. Short-term variability on mesozooplankton community in a shallow mixed estuary (Bahía Blanca, Argentina): Influence of tidal cycles and local winds

    Science.gov (United States)

    Menéndez, María C.; Piccolo, María C.; Hoffmeyer, Mónica S.

    2012-10-01

    The short-term dynamics of zooplankton in coastal ecosystems are strongly influenced by physical processes such as tides, riverine runoff and winds. In this study, we investigated the short-term changes of the representative taxa within mesozooplankton in relation to the semidiurnal tidal cycles. Also, we evaluated the influence of local winds on this short-term variability. Sampling was carried out bimonthly from December 2004 to April 2006 in a fixed point located in the inner zone of the Bahía Blanca Estuary, Argentina. Mesozooplankton samples were taken by pumps during 14-h tidal cycles at 3-h intervals, from surface and bottom. Vertical profiles of temperature and salinity as well as water samples to determine suspended particulate matter were acquired at each sampling date. All data concerning winds were obtained from a meteorological station and water level was recorded with a tide gauge. Holoplankton dominated numerically on meroplankton and adventitious fraction. Concerning holoplanktonic abundance, the highest values were attained by the calanoid copepods Acartia tonsa and Eurytemora americana. Meroplankton occurred mainly as barnacle larvae while benthic harpacticoids and Corophium sp. dominated the adventitious component. Semidiurnal tide was the main influence on the A. tonsa variability. However, noticeable differences in the abundance pattern as function of wind intensity were detected. Meroplankton abundance did not show a clear variation along the tidal cycle. Distributional pattern of harpacticoids seemed to be mainly modulated by velocity asymmetries in the tidal currents, in the same way as suspended particulate matter. However, the Corophium sp. distribution indicated probable behavioural responses associated with tides. The obtained results show how variable the mesozooplankton community structure can be over short-term time scales in mesotidal temperate estuaries. This variability should be taken into account for any zooplankton monitoring

  10. Impacts of elevated terrestrial nutrient loads and temperature on pelagic food-web efficiency and fish production.

    Science.gov (United States)

    Lefébure, R; Degerman, R; Andersson, A; Larsson, S; Eriksson, L-O; Båmstedt, U; Byström, P

    2013-05-01

    Both temperature and terrestrial organic matter have strong impacts on aquatic food-web dynamics and production. Temperature affects vital rates of all organisms, and terrestrial organic matter can act both as an energy source for lower trophic levels, while simultaneously reducing light availability for autotrophic production. As climate change predictions for the Baltic Sea and elsewhere suggest increases in both terrestrial matter runoff and increases in temperature, we studied the effects on pelagic food-web dynamics and food-web efficiency in a plausible future scenario with respect to these abiotic variables in a large-scale mesocosm experiment. Total basal (phytoplankton plus bacterial) production was slightly reduced when only increasing temperatures, but was otherwise similar across all other treatments. Separate increases in nutrient loads and temperature decreased the ratio of autotrophic:heterotrophic production, but the combined treatment of elevated temperature and terrestrial nutrient loads increased both fish production and food-web efficiency. CDOM: Chl a ratios strongly indicated that terrestrial and not autotrophic carbon was the main energy source in these food webs and our results also showed that zooplankton biomass was positively correlated with increased bacterial production. Concomitantly, biomass of the dominant calanoid copepod Acartia sp. increased as an effect of increased temperature. As the combined effects of increased temperature and terrestrial organic nutrient loads were required to increase zooplankton abundance and fish production, conclusions about effects of climate change on food-web dynamics and fish production must be based on realistic combinations of several abiotic factors. Moreover, our results question established notions on the net inefficiency of heterotrophic carbon transfer to the top of the food web. © 2013 Blackwell Publishing Ltd.

  11. The reaction of European lobster larvae (Homarus gammarus) to different quality food: effects of ontogenetic shifts and pre-feeding history.

    Science.gov (United States)

    Schoo, Katherina L; Aberle, Nicole; Malzahn, Arne M; Schmalenbach, Isabel; Boersma, Maarten

    2014-02-01

    Young larval stages of many organisms represent bottlenecks in the life-history of many species. The high mortality commonly observed in, for example, decapod larvae has often been linked to poor nutrition, with most studies focussing on food quantity. Here, we focus instead on the effects of quality and have investigated its effects on the nutritional condition of lobster larvae. We established a tri-trophic food chain consisting of the cryptophyte Rhodomonas salina, the calanoid copepod Acartia tonsa and larvae of the European lobster Homarus gammarus. In a set of experiments, we manipulated the C:N:P stoichiometry of the primary producers, and accordingly those of the primary consumer. In a first experiment, R. salina was grown under N- and P-limitation and the nutrient content of the algae was manipulated by addition of the limiting nutrient to create a food quality gradient. In a second experiment, the effect on lobster larvae of long- and short-term exposure to food of varying quality during ontogenetic development was investigated. The condition of the lobster larvae was negatively affected even by subtle N- and P-nutrient limitations of the algae. Furthermore, younger lobster larvae were more vulnerable to nutrient limitation than older ones, suggesting an ontogenetic shift in the capacity of lobster larvae to cope with low quality food. The results presented here might have substantial consequences for the survival of lobster larvae in the field, as, in the light of future climate change and re-oligotrophication of the North Sea, lobster larvae might face marked changes in temperature and nutrient conditions, thus significantly altering their condition and growth.

  12. The effects of mixed algal diets on population growth, egg productivity and nutritional profiles in cyclopoid copepods (Thermocyclops hyalinus and Mesocyclops aspericornis

    Directory of Open Access Journals (Sweden)

    Kumar Vidhya

    2014-03-01

    Full Text Available This experiment was carried out to evaluate the effect of mixed algal diet on dietary profiles of copepods. The microalgae like Spirulina platensis, Chlorella vulgaris and Azolla pinnata were mass cultured in artificial medium for a period of 20 days, cells are harvested, dried, powdered and used as feed. The small freshwater cyclopoids Thermocyclops hyalinus were compared to Mesocyclops aspericornis a species of copepod genera commonly preferred by most of the fish larvae. Both species are easily maintained in culture, when fed with mixed algal diets of equal ratios (1:1:1. Biochemical composition, egg production ratios, growth performance and fatty acids profile of the two different species were analyzed after an experimental period of 15 days, all the nutritional values were found to be high and statistically variable. On the basis of biochemical composition, egg production ratio, growth performance, amino acids and fatty acids profile it is found that M. aspericornis was the suitable candidate for larval fish diets.

  13. [Construction of suppression subtractive hybridization (SSH) library of copepod Pseudodiaptomous annandalei and its ferritin cDNA cloning and differential expression under nickel stress].

    Science.gov (United States)

    Jiang, Jie-Lan; Wang, Gui-Zhong; Wu, Li-Sheng; Li, Shao-Jing

    2012-07-01

    To study the molecular response mechanisms of copepod to nickel stress, a suppression subtractive hybridization (SSH) cDNA library of Pseudodiaptomous annandalei under nickel stress was constructed by using SSH technique, and a total of 140 clones were randomly picked from the growing colonies and identified by PCR. The recombinant rate of the library was 98.6%, and the volume of the library was 1.12 x 10(6) cfu. After the recombinant plasmids were sequenced, a partial cDNA fragment of ferritin was recognized based on BLAST searches in NCBI, with a size of 859 bp and continuously encoding 170 amino acid residues. The semi-quantitative PCR results showed that the ferritin cDNA under 24 h nickel stress was distinctly up-regulated. The successful construction of the SSH library and the obtaining of ferritin cDNA fragment would supply basis for the further study of the molecular response mechanisms of copepod to nickel stress.

  14. The ecotoxicity of binary mixtures of Imazamox and ionized ammonia on freshwater copepods: Implications for environmental risk assessment in groundwater bodies.

    Science.gov (United States)

    Di Marzio, Walter D; Cifoni, Marco; Sáenz, María E; Galassi, Diana M P; Di Lorenzo, Tiziana

    2018-03-01

    Groundwater bodies are impacted by substances such as pesticides and N-fertilizers, which usually occur in the environment as complex mixtures rather than isolated pollutants. The threat that these mixtures pose to groundwater-dwelling organisms is still poorly understood. The aims of the present study were to test the acute effect of a binary mixture of a herbicide (Imazamox) and NH 4 + on epigean (Eucyclops serrulatus) and hypogean (Diacyclops belgicus) freshwater copepod species. In addition, to evaluate if the effect of the mixture can be explained by referencing non-interaction models or by more complex interaction models; and the implications for groundwater risk assessment. Compared with the action of the compounds evaluated separately, the effects of Imazamox and NH 4 + in the binary mixture were more than additive or synergistic for both species. MixTox models evidenced a dose ratio and dose level deviations from concentration addition and independent action traditional models. The hypogean species was three times more sensitive to NH 4 + that the epigean species when assayed as a single chemical. However, D. belgicus was only 1.13 times more sensitive than E. serrulatus when NH 4 + was assayed in the mixture. The use of an integrated approach for substances that are known to interact in groundwater, should include copepods species as test organisms. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. Assessing the in situ fertilization status of two marine copepod species, Temora longicornis and Eurytemora herdmani; how common are unfertilized eggs in nature?

    Directory of Open Access Journals (Sweden)

    Rachel S Lasley-Rasher

    Full Text Available We utilized an egg staining technique to measure the in situ fertilization success of two marine copepod species, Temora longicornis and Eurytemora herdmani from May to October 2008 in coastal Maine and correlated fertilization success with environmental conditions in their habitat. T. longicornis is a free spawning species that releases eggs into the ambient seawater after mating. In contrast, E. herdmani carries eggs in an egg sac until they hatch. The proportion of fertilized eggs within E. herdmani egg sacs was significantly higher than the freely spawned clutches of T. longicornis. This may be a result of the asymmetrical costs associated with carrying vs. spawning unfertilized eggs. T. longicornis frequently laid both fertilized and unfertilized eggs within their clutch. T. longicornis fertilization was negatively associated with chlorophyll concentration and positively associated with population density in their local habitat. The fertilization status of E. herdmani egg sacs was high throughout the season, but the proportion of ovigerous females was negatively associated with an interaction between predators and the proportion of females in the population. This study emphasizes that, in addition to population level processes, community and ecosystem level processes strongly influence the fertilization success and subsequent productivity of copepods.

  16. Temporal and spatial changes in the copepod community during the 1974-1998 spring seasons in the Kuroshio region; a time period of profound changes in pelagic fish populations

    Science.gov (United States)

    Miyamoto, Hiroomi; Itoh, Hiroshi; Okazaki, Yuji

    2017-10-01

    The long-term change (1974-1998) of the pelagic copepod community in the Kuroshio region, western Pacific was examined in archival samples collected both day and night in April/May in a time period of profound changes in the pelagic fish populations. A total of 162 adult copepod species was found. The community analysis based on species composition and abundance of adult copepods identified five assemblages (A-E) by cluster analysis. These assemblages were distributed in the north-frontal area of the Kuroshio Current within the slope area (A), the Kuroshio axis area (B), the subtropical area (C, D), and the coastal area within the slope area (E), indicating that such diverse communities were formed to correspond with the gradual change in the oceanic environment across the Kuroshio Current. The abundance of copepods in the north-frontal area of the Kuroshio Current (A) was 1.6 times greater than that of the other assemblages. Kuroshio/subtropical species were abundant in the assemblage, suggesting that these species that were transported from the Kuroshio and/or subtropical regions increased in the slope region. Abundance and species richness of two assemblages (C, D), which were found in the subtropical areas were higher at night (C) than during the day (D), suggesting that diel vertical migration of copepods is one of the most important factors affecting changes in the community. Furthermore, a generalized additive model revealed that the most dominant subtropical/Kuroshio species increased in years in which the Kuroshio Current flowed further south, with the Kuroshio axis located far from the Japanese coast. In contrast, the model showed that the lower latitude of the Kuroshio axis positioned negatively affected coastal-dominant species, such as Paracalanus parvus sensu lato (s.l.). These results indicate that onshore-offshore shifts of the Kuroshio axis caused by Kuroshio meandering was an important factor involved in the inter-annual change in the copepod

  17. BDE-47 causes developmental retardation with down-regulated expression profiles of ecdysteroid signaling pathway-involved nuclear receptor (NR) genes in the copepod Tigriopus japonicus

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Dae-Sik; Han, Jeonghoon; Won, Eun-Ji; Kim, Duck-Hyun; Jeong, Chang-Bum [Department of Biological Science, College of Science, Sungkyunkwan University, Suwon 16419 (Korea, Republic of); Hwang, Un-Ki [Marine Ecological Risk Assessment Center, West Sea Fisheries Research Institute, National Fisheries Research & Development Institute, Incheon 46083 (Korea, Republic of); Zhou, Bingsheng [State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072 (China); Choe, Joonho [Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon 34141 (Korea, Republic of); Lee, Jae-Seong, E-mail: jslee2@skku.edu [Department of Biological Science, College of Science, Sungkyunkwan University, Suwon 16419 (Korea, Republic of)

    2016-08-15

    Highlights: • The developmental rate was significantly inhibited (P < 0.05) in response to BDE-47. • Expression profiles of nearly all NR genes were the highest at naupliar stages 5–6. • USP, HR96, and FTZ-F1 genes showed significant sex differences (P < 0.05) over different developmental stages. • NR gene expression patterns showed significant decreases (P<0.05) in response to BDE-47. • BDE-47 leads to molting and metamorphosis retardation and suppresses transcription of NR genes. - Abstract: 2,2′,4,4′-Tetrabromodiphenyl ether (BDE-47) is a persistent organic pollutant (POP) in marine environments. Despite its adverse effects (e.g. developmental retardation) in ecdysozoa, the effects of BDE-47 on transcription of ecdysteroid signaling pathway-involved-nuclear receptor (NR) genes and metamorphosis-related genes have not been examined in copepods. To examine the deleterious effect of BDE-47 on copepod molting and metamorphosis, BDE-47 was exposed to the harpacticoid copepod Tigriopus japonicus, followed by monitoring developmental retardation and transcriptional alteration of NR genes. The developmental rate was significantly inhibited (P < 0.05) in response to BDE-47 and the agricultural insecticide gamma-hexachlorocyclohexane. Conversely, the ecdysteroid agonist ponasterone A (PoA) led to decreased molting and metamorphosis time (P < 0.05) from the nauplius stage to the adult stage. In particular, expression profiles of all NR genes were the highest at naupliar stages 5–6 except for SVP, FTZ-F1, and HR96 genes. Nuclear receptor USP, HR96, and FTZ-F1 genes also showed significant sex differences (P < 0.05) in gene expression levels over different developmental stages, indicating that these genes may be involved in vitellogenesis. NR gene expression patterns showed significant decreases (P < 0.05) in response to BDE-47 exposure, implying that molting and metamorphosis retardation is likely associated with NR gene expression. In summary, BDE-47

  18. [METACERCERIAE OF BRACHYPHALLUS CRENARUS RUDOLPHI, 1802 (TREMATODA: HENIURIDAE) IN PLANKTON CRUSTACEANS FROM THE PROSTOR GULF (ITURUP ISLAND, RUSSIA)].

    Science.gov (United States)

    Sokolov, S G; Frenkel, S E; Gordeev, I I

    2016-01-01

    Samples of Zooplankton collected in waters of the Prostor Gulf (Iturup Island) were examined. Metacercariae of Brachyphallus crenatus were found in copepods Pseudocalanus newmani and Acartia longiremis. This is the first record of the second intermediate hosts of this species in the North Pacific.

  19. Comparative morphology of the feeding appendages of four ...

    African Journals Online (AJOL)

    Comparative morphology of the feeding appendages of four mesozooplankton species in the Sundays River estuary. H.L. Jerling, T.H. Wooldridge. Abstract. The morphology of feeding appendages of the coexisting estuarine copepods, Pseudodiaptomus hessei and Acartia longipatetla, and mysids, Rhopalophthalmus ...

  20. Comparative morphology of the feeding appendages of four ...

    African Journals Online (AJOL)

    The morphology of feeding appendages of the coexisting estuarine copepods, Pseudodiaptomus hessei and. Acartia longipatella, and mysids, RhopalophthafmU5 terranatalis and Mesopodopsis wooldridgei, were examined and compared as an aid in elucidating dietary differences. The robust mandibles of P. hessel ...

  1. Copepods in Sunda Strait

    NARCIS (Netherlands)

    Delsman, H.C.

    1949-01-01

    After having collected the plankton samples in the Java Sea on which I have reported in Treubia XVII, 1939, I thought it desirable to gather similar samples from a more oceanic area of the East Indian seas, in order to be able to make a comparison between the two collections and to try to find out

  2. Adverse effects of microplastics and oxidative stress-induced MAPK/Nrf2 pathway-mediated defense mechanisms in the marine copepod Paracyclopina nana

    Science.gov (United States)

    Jeong, Chang-Bum; Kang, Hye-Min; Lee, Min-Chul; Kim, Duck-Hyun; Han, Jeonghoon; Hwang, Dae-Sik; Souissi, Sami; Lee, Su-Jae; Shin, Kyung-Hoon; Park, Heum Gi; Lee, Jae-Seong

    2017-01-01

    Microplastic pollution causes a major concern in the marine environment due to their worldwide distribution, persistence, and adverse effects of these pollutants in the marine ecosystem. Despite its global presence, there is still a lack of information on the effect of microplastics on marine organisms at the molecular level. Herein we demonstrated ingestion and egestion of nano- (0.05 μm) and micro-sized (0.5 and 6 μm) polystyrene microbeads in the marine copepod Paracyclopina nana, and examined molecular responses to exposure to microbeads with in vivo endpoints such as growth rate and fecundity. Also, we proposed an adverse outcome pathway for microplastic exposure that covers molecular and individual levels. This study provides the first insight into the mode of action in terms of microplastic-induced oxidative stress and related signaling pathways in P. nana.

  3. Seasonal occurrence and microhabitat of the hyperparasitic monogenean Udonella fugu on the caligid Copepod Pseudocaligus fugu infecting the grass puffer Takifugu niphobles in the Seto Inland Sea, Japan

    Science.gov (United States)

    Okawachi, Hiroko; Ohtsuka, Susumu; Ismail, Norshida Binti; Venmathi Maran, B. A.; Ogawa, Kazuo

    2012-09-01

    The seasonal occurrence and microhabitat of the monogenean Udonella fugu that hyperparasitizes exclusively on adults of the caligid copepod Pseudocaligus fugu that infects the skin of the grass puffer Takifugu niphobles were investigated in the Seto Inland Sea, western Japan from November 2004 to December 2006. The udonellids occurred and bred mostly during the occurrence of P. fugu on the fish host. The average prevalence and intensity of U. fugu on P. fugu during the whole investigation were 29% and 3.6, respectively. The main attachment sites of U. fugu were the posterior side of leg 3 and the dorsal marginal side of the cephalothorax for feeding and copulation, while eggs were predominantly located on the ventral side of the urosome to avoid detachment. More attention should be paid to the ecology of U. fugu, due to recent high prevalence of P. fugu on cultured tiger puffer in western Japan.

  4. A Model to Study the Phenotypic Changes of Insect Cell Transfection by Copepod Super Green Fluorescent Protein (cop-GFP) in Baculovirus Expression System.

    Science.gov (United States)

    Shokrollahi, Narjes; Shahbazzadeh, Delavar; Pooshang-Bagheri, Kamran; Habibi-Anbouhi, Mahdi; Jahanian-Najafabadi, Ali; Behdani, Mahdi

    2016-07-01

    Baculovirus expression system is one of the most attractive and powerful eukaryotic expression systems for the production of recombinant proteins. The presence of a biomarker is required to monitor transfection efficiency or protein expression levels in insect cells. The aim of this study was to construct a baculovirus expression vector encoding a copepod super green fluorescent protein (copGFP). In this light, the resultant vector was constructed and used for transfection of Spodoptera frugiperda cells. Expression of the copGFP protein in insect cells was confirmed by fluorescent microscopy and Western-blot analysis. The application of copGFP control bacmid can be considered as an appropriate control for insect cell transfection.

  5. Ten new species of parasitic cyclopoid copepods (Crustacea) belonging to the families Bomolochidae, Philichthyidae, and Taeniacanthidae from marine fishes in Korea

    Science.gov (United States)

    Kim, Il-Hoi; Moon, Seong Yong

    2013-12-01

    Ten new species of cyclopoid copepods are described as parasites of marine fishes from Korea. Three new species of the family Bomolochidae are described as gill parasites: Orbitacolax pteragogi n. sp. from Pteragogus flagellifer (Valenciennes), Orbitacolax trichiuri n. sp. from Trichurus lepturus Linnaeus, and Orbitacolax unguifer n. sp. from Evynnis japonica Tanaka. Four species of the genus Colobomatus Hesse, 1873 of the family Philichthyidae are described as internal parasites: Colobomatus unimanus n. sp. from Pseudolabrus eoethinus (Richardson), Colobomatus recticaudatus n. sp. from Halichoeres poecilopterus (Temminck and Schlegel), Colobomatus floridus n. sp. from Hapalogenys mucronatus (Eydoux and Souleyet), and Colobomatus orientalis n. sp. from Johnius grypotus (Richardson). Three new species of the family Taeniacanthidae, including a new species belonging to a new genus, are described as gill parasites: Taeniacanthus singularis n. sp. from Halieutaea fumosa Alcock, Triacanthus luteus n. gen. n. sp. from Odontamblyopus lacepedii (Temminck and Schlegel), and Umazuracola geminus n. sp. from Stephonolepis cirrhifer (Temminck and Schlegel).

  6. Three new records of copepods (Siphonostomatoida) parasitic on marine fishes of Iraq, including the relegation of two species of Lernanthropinus to Lernanthropinus temminckii (von Nordmann, 1864).

    Science.gov (United States)

    Venmathi Maran, B A; Moon, Seong Yong; Adday, Thamir Katea; Khamees, Najim Rijab; Myoung, Jung-Goo

    2014-03-01

    Three parasitic copepods (Siphonostomatoida) belonging to three different genera were recovered from marine fishes of Iraq, and are listed here as new records. The sea lice Caligus epinepheli Yamaguti, 1936 (Caligidae) was collected from the Japanese threadfin bream, Nemipterus japonicus (Bloch). It had been frequently reported from teleost fishes around the world. The second record, comprising male and female, was another caligid, rarely caught from fishes - Hermilius longicornis Bassett-Smith, 1898, collected from the giant catfish, Netuma thalassina (Rüppell). This paper features the first description of the male of the latter species. The third record was the lernanthropid, Lernanthropinus temminckii (von Nordmann, 1864) (Lernanthropidae), redescribed based on the specimens collected from the greater lizard fish, Saurida tumbil (Bloch) (Synodontidae). In order to clarify its taxonomic status, our specimen was compared with the holotype of L. gibbosus (Pillai, 1964) from the collections of Zoological Survey of India, Kolkata, and the syntypes of L. sauridae Do in Ho and Do, 1985 and L. temminckii from the collections of the Smithsonian Institution, Washington D.C. We found similarities in the morphology of the body, mouthparts, and legs 1-4 in three above-mentioned species. The prominent feature, the setation pattern of legs 1 and 2 was similar in all the female specimens examined. In the light of this, we formally relegate L. gibbosus and L. sauridae to synonymy with L. temminckii. Another important similarity is that Lernanthropinus gibbosus, L. sauridae, and L. temminckii have exclusively been parasitic on lizardfishes (Synodontidae). The attachment site of all three copepods reported form Iraq were the gill filaments.

  7. A common-garden experiment to quantify evolutionary processes in copepods: the case of emamectin benzoate resistance in the parasitic sea louse Lepeophtheirus salmonis

    Science.gov (United States)

    2014-01-01

    Background The development of pesticide resistance represents a global challenge to food production. Specifically for the Atlantic salmon aquaculture industry, parasitic sea lice and their developing resistance to delousing chemicals is challenging production. In this study, seventeen full sibling families, established from three strains of Lepeophtheirus salmonis displaying differing backgrounds in emamectin benzoate (EB) tolerance were produced and quantitatively compared under a common-garden experimental design. Lice surviving to the preadult stage were then exposed to EB and finally identified through the application of DNA parentage testing. Results With the exception of two families (19 and 29%), survival from the infectious copepod to preadult stage was very similar among families (40-50%). In contrast, very large differences in survival following EB exposure were observed among the families (7.9-74%). Family survival post EB exposure was consistent with the EB tolerance characteristics of the strains from which they were established and no negative effect on infection success were detected in association with increased EB tolerance. Two of the lice families that displayed reduced sensitivity to EB were established from a commercial farm that had previously used this chemical. This demonstrates that resistant alleles were present on this farm even though the farm had not reported treatment failure. Conclusions To our knowledge, this represents the first study where families of any multi-cellular parasite have been established and compared in performance under communal rearing conditions in a common-garden experiment. The system performed in a predictable manner and permitted, for the first time, elucidation of quantitative traits among sea lice families. While this experiment concentrated on, and provided a unique insight into EB sensitivity among lice families, the experimental design represents a novel methodology to experimentally address both resistance

  8. Spatio-temporal Variations of Abundance, Biomass, Repproductive ...

    African Journals Online (AJOL)

    N'DOUA RAPHAEL

    2015-08-19

    Aug 19, 2015 ... Revista de biología tropical. 46(3):661-672. Jeyaraj N, Santhanam P (2012). Influence of algal diet on population density, egg production and hatching succession of the calanoid copepod, Paracalanus parvus (Claus, 1863). J. Algal Biomass Utln. 4(1):1-8. Jordan TE, DR Correll, J Miklas, DE Weller (1991).

  9. Limnology of southern African coastal lakes — new vistas from ...

    African Journals Online (AJOL)

    Characteristically relict estuarine/marine fauna (a calanoid copepod, crown crab, amphipod and fish) were present in two oligotrophic lakes, including the largest — putatively a drowned-valley lake. ... Survey findings were used to assess the suitability of these lakes as prospective habitats for exotic grass and silver carp.

  10. African Journal of Marine Science - Vol 27, No 3 (2005)

    African Journals Online (AJOL)

    Metabolic adaptations and reduced respiration of the copepod Calanoides carinatus during diapause at depth in the Angola-Benguela Front and northern Benguela upwelling regions · EMAIL FULL TEXT EMAIL FULL TEXT DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. H Auel, W Hagen, W Ekau, HM Verheye, 653- ...

  11. Spring production of Calanus finmarchicus at the Iceland-Scotland Ridge

    DEFF Research Database (Denmark)

    Jonasdottir, Sigrun; Richardson, K.; Heath, M.R.

    2008-01-01

    Distribution and reproduction activity of the calanoid copepod Calanus finmarchicus were studied in the waters between Scotland and Iceland in April 1997 during the expected time of the animals' ascent to surface waters following diapause. Ascent was taking place on both sides of the Iceland...

  12. A lasting legacy for the Baltic and North Sea GLOBEC Germany program

    DEFF Research Database (Denmark)

    Peck, M.A.; Dutz, Jörg; Voss, R.

    2012-01-01

    This preface introduces four manuscripts that form a special theme section of the GLOBEC Germany program within Progress in Oceanography. The four manuscripts link changes in physical forcing to the trophodynamic structure and function of the Baltic and North Seas. The target species of GLOBEC Ge...... Germany included various species of calanoid copepods and a small pelagic fish (Sprattus sprattus)...

  13. Live discrimination of Calanus glacialis and C. finmarchicus females: can we trust phenological differences?

    DEFF Research Database (Denmark)

    Nielsen, Torkel Gissel; Kjellerup, Sanne; Smolina, Irina

    2014-01-01

    Two key players in the Arctic and subarctic marine ecosystem are the calanoid copepods, Calanus finmarchicus and C. glacialis. Although morphologically very similar, these sibling species have different life cycles and roles in the Arctic pelagic marine ecosystem. Considering that the distributio...

  14. The Diet of Five Cichlid Fish Species from Lake Kariba, Zimbabwe ...

    African Journals Online (AJOL)

    The diet of five cichlid fish species from the littoral areas of Lake Kariba was investigated in 1996-97. Serranochromis macrocephalus, Pseudocrenilabrus philander and Pharyngochromis acuticeps fed mostly on calanoid copepods, chironomid larvae, rotifers, phytoplankton and fish fry. Oreochromis niloticus and 0.

  15. Feeding on dispersed vs. aggregated particles: The effect of zooplankton feeding behavior on vertical flux

    DEFF Research Database (Denmark)

    Koski, Marja; Boutorh, Julia; De La Rocha, Christina L.

    2017-01-01

    , pellet production and egg production rates was equivalent to a daily minimum carbon demand of ca. 10% body weight-(1) for all non-feeding copepods; the carbon demand of calanoids feeding on dispersed food was 2-3 times greater, and the carbon demand of harpacticoids and Oncaea spp. feeding on aggregates...

  16. Groundwater crustaceans of Spain, 13 (Copepoda Calanoida)

    NARCIS (Netherlands)

    Bowman, Thomas E.

    1990-01-01

    Two calanoid copepods were collected from groundwaters in Spain by the University of Amsterdam Expeditions in 1983—84 and 1985. Copidodiaptomus numidicus was found in southwestern Spain, in provincias Huelva and Sevilla. Mixodiaptomus laciniatus, previously known in Spain only from the Pyrenees, was

  17. Selective grazing of Temora longicornis in different stages of a Phaeocystis globosa bloom - a mesocosm study

    DEFF Research Database (Denmark)

    Koski, Marja; Dutz, Jörg; Breteler, W.C.M.K.

    2005-01-01

    Selective grazing of a calanoid copepod Temora longicornis was measured during different stages of a Phaeocystis globosa bloom, in order to reveal (1) if T longicornis feeds on single cells and/or colonies of P. globosa in the presence of alternative food sources, (2) if copepod food selection...... of alternative food sources. In contrast, feeding on single cells was never significant, and the total contribution of P globosa to carbon ingestion of T longicornis was minor. T longicornis fed most actively on the decaying colonies, whereas during the peak of the bloom copepods selected against P globosa...

  18. Ranking sediment samples from three Spanish estuaries in relation to its toxicity for two benthic species: the microalga Cylindrotheca closterium and the copepod Tisbe battagliai.

    Science.gov (United States)

    Araújo, Cristiano V M; Diz, Fernando R; Tornero, Victoria; Lubián, Luís M; Blasco, Julián; Moreno-Garrido, Ignacio

    2010-02-01

    The present study assesses the sediment toxicity levels of three Spanish estuaries, as well as the suitability of two microorganisms, the benthic microalga Cylindrotheca closterium and the harpacticoid copepod Tisbe battagliai, as test organisms in whole-sediment toxicity assays. The sensitivity of both species to potentially polluted sediments was compared. Three sites at the southwest of the Iberian Peninsula were chosen: the Ría of Huelva, the Guadalquivir Estuary, and the Bay of Algeciras. Inhibition data were based on growth for C. closterium and fecundity for T. battagliai. No toxicity was recorded for the microalga in the Guadalquivir Estuary and the Bay of Algeciras. However, for T. battagliai, inhibition of fecundity was approximately 50% in those zones, indicating higher sensitivity. Samples from stations in the Ría of Huelva were the most toxic of all those assayed; inhibition values higher than 90% were obtained for both organisms. The highest values for total metal concentrations such as arsenic (As), cadmium (Cd), copper (Cu), iron (Fe), lead (Pb), tin (Sn), and zinc (Zn) were found in the Ría of Huelva, which can be classified as severely impacted. The Guadalquivir Estuary and the Bay of Algeciras can be considered moderately impacted. In general, both methodologies are suitable for application in ecotoxicological studies. Copyright 2009 SETAC.

  19. In vivo effects of UV radiation on multiple endpoints and expression profiles of DNA repair and heat shock protein (Hsp) genes in the cycloid copepod Paracyclopina nana

    Energy Technology Data Exchange (ETDEWEB)

    Won, Eun-Ji; Han, Jeonghoon [Department of Biological Science, College of Science, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Lee, Yeonjung; Kumar, K. Suresh; Shin, Kyung-Hoon [Department of Marine Sciences and Convergent Technology, College of Science and Technology, Hanyang University, Ansan 426-791 (Korea, Republic of); Lee, Su-Jae [Department of Life Sciences, College of Natural Sciences, Hanyang University, Seoul 133-791 (Korea, Republic of); Park, Heum Gi, E-mail: hgpark@gwnu.ac.kr [Department of Marine Resource Development, College of Life Sciences, Gangneung-Wonju National University, Gangneung 210-702 (Korea, Republic of); Lee, Jae-Seong, E-mail: jslee2@skku.edu [Department of Biological Science, College of Science, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of)

    2015-08-15

    Highlights: • UV-B radiation induced a significant reduction of the re-brooding rate of ovigerous females. • A dose-dependent decrease in food ingestion and the rate of assimilation to the body upon UV radiation. • Expression of base excision repair-associated and hsp chaperoning genes was significantly increased upon UV radiation in P. nana. - Abstract: To evaluate the effects of ultraviolet (UV) radiation on energy acquisition and consumption, the copepod Paracyclopina nana was irradiated with several doses (0–3 kJ/m{sup 2}) of UV. After UV radiation, we measured the re-brooding success, growth pattern of newly hatched nauplii, ingestion rate, and assimilation of diet. In addition, we checked the modulated patterns of DNA repair and heat shock protein (hsp) chaperoning genes of P. nana. UV-B radiation induced a significant reduction (7–87%) of the re-brooding rate of ovigerous females, indicating that UV-induced egg sac damage is closely correlated with a reduction in the hatching rate of UV-irradiated ovigerous female offspring. Using chlorophyll a and stable carbon isotope incubation experiments, we found a dose-dependent decrease (P < 0.05) in food ingestion and the rate of assimilation to the body in response to UV radiation, implying that P. nana has an underlying ability to shift its balanced-energy status from growth and reproduction to DNA repair and adaptation. Also, expression of P. nana base excision repair (BER)-associated genes and hsp chaperoning genes was significantly increased in response to UV radiation in P. nana. These findings indicate that even 1 kJ/m{sup 2} of UV radiation induces a reduction in reproduction and growth patterns, alters the physiological balance and inhibits the ability to cope with UV-induced damage in P. nana.

  20. Influence of ocean acidification on plankton community structure during a winter-to-summer succession: An imaging approach indicates that copepods can benefit from elevated CO2 via indirect food web effects

    Science.gov (United States)

    Taucher, Jan; Haunost, Mathias; Boxhammer, Tim; Bach, Lennart T.; Algueró-Muñiz, María; Riebesell, Ulf

    2017-01-01

    Plankton communities play a key role in the marine food web and are expected to be highly sensitive to ongoing environmental change. Oceanic uptake of anthropogenic carbon dioxide (CO2) causes pronounced shifts in marine carbonate chemistry and a decrease in seawater pH. These changes–summarized by the term ocean acidification (OA)–can significantly affect the physiology of planktonic organisms. However, studies on the response of entire plankton communities to OA, which also include indirect effects via food-web interactions, are still relatively rare. Thus, it is presently unclear how OA could affect the functioning of entire ecosystems and biogeochemical element cycles. In this study, we report from a long-term in situ mesocosm experiment, where we investigated the response of natural plankton communities in temperate waters (Gullmarfjord, Sweden) to elevated CO2 concentrations and OA as expected for the end of the century (~760 μatm pCO2). Based on a plankton-imaging approach, we examined size structure, community composition and food web characteristics of the whole plankton assemblage, ranging from picoplankton to mesozooplankton, during an entire winter-to-summer succession. The plankton imaging system revealed pronounced temporal changes in the size structure of the copepod community over the course of the plankton bloom. The observed shift towards smaller individuals resulted in an overall decrease of copepod biomass by 25%, despite increasing numerical abundances. Furthermore, we observed distinct effects of elevated CO2 on biomass and size structure of the entire plankton community. Notably, the biomass of copepods, dominated by Pseudocalanus acuspes, displayed a tendency towards elevated biomass by up to 30–40% under simulated ocean acidification. This effect was significant for certain copepod size classes and was most likely driven by CO2-stimulated responses of primary producers and a complex interplay of trophic interactions that allowed this