new data on the early development of hysterothylacium aduncum (nematoda, anisakidae).this note reports on incidental observations of the early development of the third-stage larvae of hysterothylacium aduncum from gadid fishes. gravid h. aduncum females were collected from pollachius virens, pollachius pollachius. gadus morhua, and molva molva in norwegian waters. the eggs were incubated at 20 per thousand salinity and 5 c. spontaneous hatching of third-stage larvae was observed 10-25 days after egg deposition. these larvae were long lived and could infect acartia tonsa copepods ...19989645866
aquatic toxicity of glyphosate-based formulations: comparison between different organisms and the effects of environmental factors.glyphosate-based herbicides (e.g. roundup) are extensively used in the aquatic environment, but there is a paucity of data on the toxicity of the formulated products and the influences by environmental factors. in this study, the acute toxicity of technical-grade glyphosate acid, isopropylamine (ipa) salt of glyphosate, roundup and its surfactant polyoxyethylene amine (poea) to microtox bacterium (vibrio fischeri), microalgae (selenastrum capricornutum and skeletonema costatum), protozoa (tetrah ...200312821000
viable but nonculturable vibrio cholerae o1 in the aquatic environment of argentina, as in other countries of latin america, cholera has occurred in an epidemic pattern. vibrio cholerae o1 is native to the aquatic environment, and it occurs in both culturable and viable but nonculturable (vnc) forms, the latter during interepidemic periods. this is the first report of the presence of vnc v. cholerae o1 in the estuarine and marine waters of the rio de la plata and the argentine shelf of the atlantic ocean, respectively. employing immunofluorescence and pcr methods, ...200415574951
bacteria associated with the surface and gut of marine copepods.little is known about the nature of bacteria associated with the surface and gut of marine copepods, either in laboratory-reared animals or in the natural environment. nor is it known whether such animals possess a gut flora. the present report deals with studies of microorganisms isolated from healthy, laboratory-reared copepods of the species acartia tonsa dana, from several species of wild copepods collected from a marine or estuarine environment, and from laboratory dishes containing moribun ...197916345368
association of vibrio cholerae o1 el tor and o139 bengal with the copepods acartia tonsa and eurytemora affinis.the association of vibrio cholerae with zooplankton has been suggested as an important factor in transmission of human epidemic cholera, and the ability to colonize zooplankton surfaces may play a role in the temporal variation and predominance of the two different serogroups (v. cholerae o1 el tor and o139) in the aquatic environment. to date, interactions between specific serogroups and species of plankton remain poorly understood. laboratory microcosm experiments were carried out to compare q ...200717951440
association of vibrio cholerae with plankton in coastal areas of mexico.the el niño event of 1997/1998 provided an opportunity to carry out a field experiment in which the relationship of sea surface temperature and the association of vibrio cholerae with marine plankton could be assessed in mexican coastal and estuarine areas. plankton samples were collected from may 1997 through june 1999. sites included the mexican ports of veracruz, coatzacoalcos and frontera in the gulf of mexico and ensenada, guaymas, mazatlán, manzanillo, acapulco and oaxaca in the pacific oc ...200918793311
attachment of the peritrich epibiont zoothamnium intermedium precht, 1935 (ciliophora, peritrichia) to artificial substrates in a natural environment.peritrich ciliates are commonly found as epibionts, colonizing living organisms, or attached to non-living substrates in freshwater, estuarine and marine environments. several species of peritrich epibionts are obligate, which means that they are able to only colonize other organisms, while others are facultative attaching to living or non-living substrates. the peritrich zoothamnium intermedium is commonly found as epibiont on the copepod species acartia tonsa and eurytemora affinis in chesapea ...200819197496
differential effects of nutrient-limited primary production on primary, secondary or tertiary consumers.nutritional imbalances between predator and prey are the rule rather than the exception at the lower end of food webs. we investigated the role of different grazers in the propagation of nutritionally imbalanced primary production by using the same primary producers in a three-trophic-level food chain and a four-trophic-level food chain experimental setup. the three-trophic-level food chain consisted of a classic single-cell primary producer (rhodomonas salina), a metazoan grazer (the copepod ac ...201019784675
feast or flee: bioelectrical regulation of feeding and predator evasion behaviors in the planktonic alveolate favella sp. (spirotrichia).alveolate (ciliates and dinoflagellates) grazers are integral components of the marine food web and must therefore be able to sense a range of mechanical and chemical signals produced by prey and predators, integrating them via signal transduction mechanisms to respond with effective prey capture and predator evasion behaviors. however, the sensory biology of alveolate grazers is poorly understood. using novel techniques that combine electrophysiological measurements and high-speed videomicrosco ...201626567352
comparison of the metabolism of acartia clausi and a. tonsa: influence of temperature and the marseilles region (french mediterranean coast), a. clausi is one of the most abundant copepod species of the gulf of fos while a. tonsa constitutes the almost exclusive copepod species of the berre lagoon, a neighbouring semi-closed brackish area communicating with the gulf. as different ecophysiological capabilities to stand the various temperature, salinity and food conditions could explain why these two species do not coexist in the same environment, comparative experiments were perfor ...200010727687
induction of toxin production in dinoflagellates: the grazer makes a difference.the dinoflagellate alexandrium minutum has previously been shown to produce paralytic shellfish toxins (pst) in response to waterborne cues from the copepod acartia tonsa. in order to investigate if grazer-induced toxin production is a general or grazer-specific response of a. minutum to calanoid copepods, we exposed two strains of a. minutum to waterborne cues from three other species of calanoid copepods, acartia clausi, centropages typicus and pseudocalanus sp. both a. minutum strains respond ...200818283499
man-induced hydrological changes, metazooplankton communities and invasive species in the berre lagoon (mediterranean sea, france).the berre lagoon has been under strong anthropogenic pressure since the early 1950s. the opening of the hydroelectric edf power plant in 1966 led to large salinity drops. the zooplankton community was mainly composed of two common brackish species: acartia tonsa and brachionus plicatilis. since 2006, european litigation has strongly constrained the input of freshwater, maintaining the salinity above 15. a study was performed between 2008 and 2010 to evaluate how these modifications have impacted ...201222776776
sublethal stress: impact of solar uv radiation on protein synthesis in the copepod acartia tonsa.aquatic organisms respond to environmental challenges such as thermal stress with the rapid induction of highly conserved polypeptides known as stress proteins or heat shock proteins (hsps). solar ultraviolet radiation (uvr, 280-400 nm) is an important environmental stressor in marine ecosystems. here, we present results of experiments conducted with the marine copepod acartia tonsa to follow the de novo protein synthesis and measure the level of constitutive and inducible isoforms of the hsp70 ...200921258623
do inactivated microbial preparations improve life history traits of the copepod acartia tonsa?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 ...201121213117
morphological characterization and intraspecific variation of zoothamnium intermedium precht, 1935 (ciliophora, peritrichia) attached to calanoid copepods in the chesapeake bay, usa.a redescription of zoothamnium intermedium precht, 1935, a peritrich epibiont on copepods, is provided using specimens colonizing acartia tonsa and eurytemora affinis in chesapeake bay, usa. bell-shaped zooids of z. intermedium ranged in size from 31.2-54.7 microm x 16.7-31.3 microm in vivo. a single contractile vacuole and a "c shaped" macronucleus lie in the upper half of the body. colonies had up to 30 zooids, but most presented two to four zooids. the single myoneme was continuous from the z ...200818681843
growth of the peritrich epibiont zoothamnium intermedium precht, 1935 (ciliophora, peritrichia) estimated from laboratory experiments.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 (zoo ...200818660977
interspecific and nutrient-dependent variations in stable isotope fractionation: experimental studies simulating pelagic multitrophic systems.stable isotope signatures of primary producers display high inter- and intraspecific variation. this is assigned to species-specific differences in isotope fractionation and variable abiotic conditions, e.g., temperature, and nutrient and light availability. as consumers reflect the isotopic signature of their food source, such variations have direct impacts on the ecological interpretation of stable isotope data. to elucidate the variability of isotope fractionation at the primary producer leve ...200717943319
does gender really matter in contaminant exposure? a case study using invertebrate models.exposure to contaminants in the environment is indiscriminate and multiple species/populations of all sexes are potentially at risk. in this paper we examine the current information available on gender specific differences in invertebrates following exposure to environmental contaminants. because of their close association with the environment and diversity of habitats, invertebrates are uniquely at risk for adverse responses to pollutants. since 97% of all animal species are invertebrates, it w ...200717097631
fitness consequences for copepods feeding on a red tide dinoflagellate: deciphering the effects of nutritional value, toxicity, and feeding behavior.phytoplankton exhibit a diversity of morphologies, nutritional values, and potential chemical defenses that could affect the feeding and fitness of zooplankton consumers. however, how phytoplankton traits shape plant-herbivore interactions in the marine plankton is not as well understood as for terrestrial or marine macrophytes and their grazers. the occurrence of blooms of marine dinoflagellates such as karenia brevis suggests that, for uncertain reasons, grazers are unable to capitalize on, or ...200616261377
spatial and temporal patterns in the occurrence of peritrich ciliates as epibionts on calanoid copepods in the chesapeake bay, usa.we investigated temporal and spatial patterns of distribution in two peritrich ciliates (i.e. zoothamnium intermedium and epistylis sp.) living as epibionts on calanoid copepods (i.e. acartia tonsa and eurytemora affinis) in chesapeake bay. net tow samples collected along the main axis of the bay were analyzed to estimate the occurrence of epibionts on copepods and to explore relationships among infestation prevalence, host abundance, and environmental variables. zoothamnium intermedium and epis ...200515927000
the effects of power station entrainment passage on three species of marine planktonic crustacean, acartia tonsa (copepoda), crangon crangon (decapoda) and homarus gammarus (decapoda).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 aff ...200414749060
uptake and accumulation of dissolved, radiolabeled nodularin in baltic sea zooplankton.the mass occurrence of toxic cyanobacteria is a recurrent phenomenon in the baltic sea. grazers may obtain toxins either through ingestion or by direct exposure to dissolved toxins. despite this, there is little knowledge about the accumulation of cyanobacterial toxins in planktonic organisms present during these blooms. toxin analyses of tissue samples are complicated to carry out and, because of the small size of microscopic planktonic organisms, often difficult to execute. therefore, we wante ...200312539144
experimental infection of atlantic salmon (salmo salar) with marine eubothrium sp. (cestoda: pseudophyllidea): observations on the life cycle, aspects of development and growth of the parasite.the life cycle of marine eubothrium sp. (cestoda: pseudophyllidea), from atlantic salmon (salmo salar l.) was experimentally completed in one year and included only one intermediate host (acartia tonsa dana) (copepoda: calanoida). adult cestodes were collected from farmed salmon, and ripe eggs released by the cestodes were fed to acartia tonsa. ingested eggs hatched in the gut and the larvae developed in the haemocoel of the copepod for 15 days at 16 degrees c. a total of 170 seawater-reared sal ...200111437125
experimental infections of copepods and sticklebacks gasterosteus aculeatus with small ensheathed and large third-stage larvae of anisakis simplex (nematoda, ascaridoidea, anisakidae).free-swimming ensheathed larvae of anisakis simplex were shown experimentally to be ingested by the copepods oitona similis and acartia tonsa and by the nauplii of barnacles balanus sp. the larvae did not grow in the copepod hemocoel. experimental infections of various malacostracans were unsuccessful. sticklebacks gasterosteus aculeatus are naturally infected with larvae of a. simplex in coastal brackish water. such sticklebacks may have acquired the infection by eating either a crustacean host ...200111199846
toxic effect of the bloom-forming trichodesmium sp. (cyanophyta) to the copepod acartia tonsa.the toxicity of the marine cyanobacterium trichodesmium sp. to the copepod acartia tonsa was assessed in a series of experiments during a trichodesmium bloom off the north carolina coast in late october 1992. healthy intact cells of trichodesmium sp. were not toxic to a. tonsa and were ingested by a. tonsa when no other foods were available. however, homogenized trichodesmium cells were toxic to a. tonsa, suggesting that trichodesmium sp. contains certain type(s) of intracellular biotoxins. this ...19947952947
life cycle and structure of the fish digenean brachyphallus crenatus (hemiuridae).cystophorous cercariae from retusa obtusa (montagu) (gastropoda, opisthobranchia, retusidae) develop into adults of brachyphallus crenatus (rudolphi, 1802) odhner, 1905 (hemiuridae). the free-swimming cercariae were ingested by laboratory-reared acartia tonsa dana, and the cercarial body was injected into the hemocoel of the copepod. two-week-old metacercariae held at 15 c were infective to stickleback gasterosteus aculeatus linnaeus. the cercariae of b. crenatus are very similar to the cercaria ...19921556648
bloom-forming cyanobacteria support copepod reproduction and development in the baltic 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 ...201425409500
grazers and phytoplankton growth in the oceans: an experimental and evolutionary perspective.the taxonomic composition of phytoplankton responsible for primary production on continental shelves has changed episodically through earth history. geological correlations suggest that major changes in phytoplankton composition correspond in time to changes in grazing and seawater chemistry. testing hypotheses that arise from these correlations requires experimentation, and so we carried out a series of experiments in which selected phytoplankton species were grown in treatments that differed w ...201324204815
diet and food selection by ramnogaster arcuata (osteichthyes, clupeidae).the goals of this study were to describe the diet and estimate the trophic level and food selection of jenyns's sprat ramnogaster arcuata, one of the common fishes in the bahía blanca estuary in argentina. the copepods acartia tonsa [53·7% index of relative importance (i(ri))] and eurytemora americana (13·4% i(ri)), the mysid arthromysis magellanica (13·9%i(ri)) and the small shrimp peisos petrunkevitchi (8·2% i(ri)) were the most important food items for this species, and its diet exhibited mon ...201121651549
larval metabolism of the epicaridian isopod parasite probopyrus pandalicola and metabolic effects of p. pandalicola on its copepod intermediate host acartia tonsa. 1976236135
influence of las on marine calanoid copepod population dynamics and potential reproduction.the toxicity of linear alkyl benzene sulfonate (las) to marine invertebrates is well documented under laboratory conditions using single-species tests. it is less known how las affects natural populations of aquatic organisms. we hypothesised that las was more toxic to the calanoid copepod acartia sp. under natural conditions than acartia tonsa under cultured conditions in the laboratory. this hypothesis was checked by a direct comparison of las toxicity in single-species and model (mesocosm) st ...200312758005
copepod growth and diatoms: insensitivity of acartia tonsa to the composition of semi-natural plankton mixtures manipulated by silicon:nitrogen ratios in mesocosms.the feeding selectivity and the growth and reproductive success of the copepod acartia tonsa have been studied in mesocosms fertilized at different si:n ratios (0-1.75:1) and, therefore, at different compositions of the phytoplankton communities. phytoplankton composition showed a strong response to nutrient ratios, with diatoms comprising >90% at si:n ratios >1:1 of total biomass as opposed to <20% at the lowest ratio. a. tonsa strongly preferred feeding on motile prey (flagellates and ciliates ...200918985392
biochemical and toxicological effects of organic (herbicide primextra(®) gold tz) and inorganic (copper) compounds on zooplankton and phytoplankton europe, mainly in the mediterranean region, an intensive usage of pesticides was recorded during the past 30 years. according to information from agricultural cooperatives of the mondego valley (figueira da foz, portugal), primextra(®) gold tz is the most used herbicide in corn crop fields and one of the 20 best-selling herbicides in portugal. copper is mainly used in pesticide formulations. this study aims to determine the ecotoxicological and biochemical (namely fatty acid profiles) effects ...201627239776
infestation of the copepod acartia tonsa with the stalked ciliate entire population of the copepod acartia tonsa in the patuxent river, maryland, was infested with a stalked protozoan of the genus zoothamnium. each copepod had 25 to 200 ciliates attached around the appendages. the infestation occurred at the time when acartia tonsa was being replaced as the dominant copepod by acartia clausi.196417806812
potential ecotoxicity of metals leached from antifouling paint particles under different salinities.antifouling paint particles (apps) are residues generated during maintenance of vessels. in boat maintenance areas of south america, waste generation and disposal are not completely regulated. therefore, apps can enter into the aquatic environment and act as a source of contamination by metals and other biocides. thus, the aim of the present study was to evaluate the potential ecotoxicity of the metal mixture present in apps leached under different salinities. therefore, the copepod acartia tons ...201829102905
content of essential fatty acids in cultivated acartia tonsa nauplii fed a dha-deficient tetraselmis sp. concentrate. 201325141657
the toxic effect of the antibiotic metronidazole on aquatic organisms.the acute toxicity of metronidazole was tested on freshwater and marine organisms. the tests showed effect on chlorella sp. and selenastrum capricornutum. 72-hr ec10 of 2.03 mg/l and 19.9 mg/l respectively and 72-hr ec50 values of 12.5 mg/l and 40.4 mg/l respectively were among the results obtained. no acute lethal effect was observed on acartia tonsa or brachydanio rerio. the study demonstrates the potential ecotoxic effect of metronidazole, suggesting the need for further investigations of the ...19979394449
on the morphology and life-history of hemiurus luehei odhner, 1905 (digenea: hemiuridae).previously undescribed cystophorous cercariae which develop in sporocyst germinal sacs in the tectibranch opisthobranch philine denticulata (adams) are shown to be cercariae of hemiurus luehei odhner, 1905 (hemiuridae), a common stomach parasite of clupeid and salmonid fishes off the atlantic coast of europe, in the baltic and the mediterranean sea. the free-swimming cercariae are seized by calanoid copepods. temora longicornis (müller) and acartia tonsa dana acted as suitable experimental inter ...19902230028
relative sensitivity of one freshwater and two marine acute toxicity tests as determined by testing 30 offshore e & p chemicals.acute toxicity of 30 offshore e & p (exploration and production) chemicals was measured using the three standard test organisms daphnia magna (freshwater cladoceran), acartia tonsa (marine copepod) and skeletonema costatum (marine diatom alga). test chemicals included 20 water-soluble and 10 (partially) non-soluble products. for 22 out of the 30 chemicals, the difference in sensitivity between the three tests varied within one order of magnitude. a very good correlation was found between the two ...200211827290
mortality and lc50 values for several stages of the marine copepod tigriopus brevicornis (müller) exposed to the metals arsenic and cadmium and the pesticides atrazine, carbofuran, dichlorvos, and malathion.the toxicity of three insecticides (carbofuran, dichlorvos, malathion), an herbicide (atrazine), and two metals (arsenic and cadmium) to ovigerous females, copepodids, and nauplii of tigriopus brevicornis was determined by 96-h semistatic (or static-renewal) bioassays. freshly prepared aqueous stock solutions of these pesticides and metals were diluted to appropriate concentrations. mortalities were recorded and test solutions were changed completely each day up to 96 h. the rate of mortality wa ...19989679687
isolation and characterization of bacteria colonizing acartia tonsa copepod eggs and displaying antagonist effects against vibrio anguillarum, vibrio alginolyticus and other pathogenic strains.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 ...201729085344
the chronic toxicity of molybdate to marine organisms. i. generating reliable effects data.a scientific research program was initiated by the international molybdenum association (imoa) which addressed identified gaps in the environmental toxicity data for the molybdate ion (moo(4)(2-)). these gaps were previously identified during the preparation of eu-reach-dossiers for different molybdenum compounds (european union regulation on registration, evaluation, authorization and restriction of chemical substances; ec, 2006). evaluation of the open literature identified few reliable marine ...201222663766
brominated flame retardants: activities in a crustacean development test and in an ecdysteroid screening assay.brominated flame retardants (bfrs) were investigated for toxic effects both in vivo and in vitro in two invertebrate bioassays. subchronic effects of tetrabromobisphenol a (tbbpa), tribromophenol (tbp), and four polybrominated diphenyl ethers ([pbdes]; bde-28, bde-47, bde-99, and bde-100) on larval development of the marine copepod acartia tonsa were studied. for tbbpa and tbp 5-d effective median concentration (ec50) values for inhibition of the larval development rate were 125 and 810 microg/l ...200515720001
Displaying items 1 - 43 of 43