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1
Piasecki, Wojciech, Balu Alagar Venmathi Maran, and Susumu Ohtsuka. "Are We Ready to Get Rid of the Terms “Chalimus” and ”Preadult” in the Caligid (Crustacea: Copepoda: Caligidae) Life Cycle Nomenclature?" Pathogens 12, no. 3 (2023): 460. http://dx.doi.org/10.3390/pathogens12030460.
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In view of recent studies, we suggest that the term “preadult” should not be used in scientific reports on Copepoda parasitic on fishes as having no explicit meaning or further justification. Consequently, the term “chalimus” with its use currently restricted in the Caligidae to at most two instars in the life cycles of species of Lepeophtheirus, also becomes redundant. In our new understanding, both the chalimus and preadult stages should be referred to as the respective copepodid stages (II through V, in integrative terminology). The terminology for the caligid copepod life cycle thereby becomes consistent with that for the homologous stages of other podoplean copepods. We see no justification for keeping “chalimus” and “preadult” even as purely practical terms. To justify this reinterpretation, we comprehensively summarize and reinterpret the patterns of instar succession reported in previous studies on the ontogeny of caligid copepods, with special attention to the frontal filament. Key concepts are illustrated in diagrams. We conclude that, using the new integrative terminology, copepods of the family Caligidae have the following stages in their life cycles: nauplius I, nauplius II (both free-living), copepodid I (infective), copepodid II (chalimus 1), copepodid III (chalimus 2), copepodid IV (chalimus 3/preadult 1), copepodid V (chalimus 4/preadult 2), and adult (parasitic). With this admittedly polemical paper, we hope to spark a discussion about this terminological problem.
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Barth-Jensen, Coralie, Malin Daase, M. R. Ormańczyk, Øystein Varpe, Sławomir Kwaśniewski, and Camilla Svensen. "High abundances of small copepods early developmental stages and nauplii strengthen the perception of a non-dormant Arctic winter." Polar Biology 45, no. 4 (2022): 675–90. http://dx.doi.org/10.1007/s00300-022-03025-4.
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AbstractThe traditional view is that the Arctic polar night is a quiescent period for marine life, but recent reports of high levels of feeding and reproduction in both pelagic and benthic taxa have challenged this. We examined the zooplankton community present in Svalbard fjords, coastal waters, and the shelf break north of Svalbard, during the polar night. We focused on the population structure of abundant copepods (Calanus finmarchicus, Calanus glacialis, Metridia longa, Oithona similis, Pseudocalanus spp., Microcalanus spp., and Microsetella norvegica) sampled using 64-µm mesh nets. Numerically, copepod nauplii (≥ 50%) and the young developmental stages of small copepods (< 2 mm prosome length as adult) dominated the samples. Three main patterns were identified: (1) large Calanus spp. were predominantly older copepodids CIV–CV, while (2) the small harpacticoid M. norvegica were adults. (3) For other species, all copepodid stages were present. Older copepodids and adults dominated populations of O. similis, Pseudocalanus spp. and M. longa. In Microcalanus spp., high proportion of young copepodids CI–CIII indicated active winter recruitment. We discuss the notion of winter as a developing and reproductive period for small copepods in light of observed age structures, presence of nauplii, and previous knowledge about the species. Lower predation risks during winter may, in part, explain why this season could be beneficial as a period for development. Winter may be a key season for development of small, omnivorous copepods in the Arctic, whereas large copepods such as Calanus spp. seems to be reliant on spring and summer for reproduction and development.
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Kabata, Z. "The developmental stages of Neobrachiella robusta (Wilson, 1912), a parasitic copepod of Sebastes (Teleostei: Scorpaeniformes)." Canadian Journal of Zoology 65, no. 6 (1987): 1331–36. http://dx.doi.org/10.1139/z87-210.
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The morphology of the developmental stages of Neobrachiella robusta (Wilson, 1912) (Copepoda: Siphonostomatoida) is described. The copepod is parasitic on the gill rakers of Sebastes alutus (Gilbert, 1890) (Teleostei: Scorpaeniformes). The life cycle of this copepod consists of a copepodid stage, followed by four chalimus stages and a relatively long preadult stage, which undergoes extensive metamorphosis. The copepods aggregate on the outer row of long gill rakers of the first gill arch, as many as 97% of them being attached to these rakers. Some of the rakers become distorted, but a connection between the presence of N. robusta and these abnormalities could not be established.
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Mulyadi, Mulyadi, and Conni M. Sidabalok. "PENGARUH MUSIM TERHADAP KERAGAMAN DAN KELIMPAHAN KOPEPODA (KRUSTASEA) DI PERAIRAN MANGROVE ESTUARI T. N. UJUNG KULON, BANTEN." Berkala Penelitian Hayati 15, no. 2 (2010): 191–97. http://dx.doi.org/10.23869/bphjbr.15.2.201015.
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An observation on Copepoda diversity and abundance in three mangrove estuaries in Ujung Kulon National Park, Banten was carried out in June and November 2008. The objective of this observation was to investigate the relationship between diversity and abundance of copepods with some environmental factors which affected the distribution in dry and rainy seasons. A total of 28 species from 17 genera and 14 families of copepods were recorded. The highest density of the copepod community was recorded in June (dry season) while the lowest density was in November (rainy season). The diversity, abundance and distribution of copepods were found to be different in the three sites.
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Bernot, James P., Geoffrey A. Boxshall, and Keith A. Crandall. "A synthesis tree of the Copepoda: integrating phylogenetic and taxonomic data reveals multiple origins of parasitism." PeerJ 9 (August 18, 2021): e12034. http://dx.doi.org/10.7717/peerj.12034.
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The Copepoda is a clade of pancrustaceans containing 14,485 species that are extremely varied in their morphology and lifestyle. Not only do copepods dominate marine plankton and sediment communities and make up a sizeable component of the freshwater plankton, but over 6,000 species are symbiotically associated with every major phylum of marine metazoans, mostly as parasites. Unfortunately, our understanding of copepod evolutionary relationships is relatively limited in part because of their extremely divergent morphology, sparse taxon sampling in molecular phylogenetic analyses, a reliance on only a handful of molecular markers, and little taxonomic overlap between phylogenetic studies. Here, a synthesis tree method is used to integrate published phylogenies into a more comprehensive tree of copepods by leveraging phylogenetic and taxonomic data. A literature review in this study finds fewer than 500 species of copepods have been sampled in molecular phylogenetic studies. Using the Open Tree of Life platform, those taxa that have been sampled in previous phylogenetic studies are grafted together and combined with the underlying copepod taxonomic hierarchy from the Open Tree of Life Taxonomy to make a synthesis phylogeny of all copepod species. Taxon sampling with respect to molecular phylogenetic analyses is reviewed for all orders of copepods and shows only 3% of copepod species have been sampled in phylogenetic studies. The resulting synthesis phylogeny reveals copepods have transitioned to a parasitic lifestyle on at least 14 occasions. We examine the underlying phylogenetic, taxonomic, and natural history data supporting these transitions to parasitism; review the species diversity of each parasitic clade; and identify key areas for further phylogenetic investigation.
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Izawa, Kunihiko. "Free-living stages of the parasitic copepod Lernanthropinus labracoglossae Izawa, 2014 (Siphonostomatoida, Lernanthropidae), reared from eggs." Crustaceana 87, no. 14 (2014): 1691–98. http://dx.doi.org/10.1163/15685403-00003377.
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Free-living stages, comprising two naupliar stages and the infective copepodid I, of the parasitic copepod Lernanthropinus labracoglossae Izawa, 2014 are described. The larvae were reared from eggs detached from an ovigerous female, recovered from the branchial lamellae of the Japanese actinopterygian fish Labracoglossa argentiventris Peter, 1866 (Kyphosidae). The number of naupliar stages prior to copepodopid I in the Lernanthropidae is the same as in the Caligidae, Pseudohatschekidae and Trebiidae. The copepodid I of the species has a frontal filament, as do representatives of the Caligidae, Pandaridae and Trebiidae. However, this is regarded as a vestigial feature in the last two families. Copepodid I of L. labracoglossae has a 6-segmented antennule, including the naked first segment, as do the first copepodids of eudactylinid copepods.
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Sari, Elda, Nora Idiawati, and Sukal Minsas. "COMPOSITION AND COMMUNITY STRUCTURE OF COPEPOD IN KAKAP RIVER ESTUARY, KUBU RAYA DISTRICT WEST BORNEO." BIOLOGICA SAMUDRA 3, no. 1 (2021): 54–66. http://dx.doi.org/10.33059/jbs.v3i1.3245.
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The research of composition and community structure of copepods in Kakap river estuary, Kubu Raya District, West Borneo was conducted from October to December 2020. The purpose of this study is to determine the composition and the community structure of copepod in Kakap river estuary, Kubu Raya District, West Borneo. This study used a purposive sampling method at four stations. Copepod samples were taken using plankton net. During the research, the total number of copepods that have been identified from 4 stations are 11 species from 3 orders, 4 families and 8 genera. Copepoda that has been obtained has the composition, namly Cyclopoids 5 species, Harpacticoida 3 species, Calanoida 2 species. The copepod density in Kakap river estuary ranged from 7,9-103,3 Ind / l, the diversity index (H ') ranged from 0 to 1.9, the evenness index (E) ranged from 0 - 0,9 and the dominance index (C) ranged from 0,2 - 1. The result of copepod density correlation analysis is that negatively correlated with -1,000 current parameter and positively correlated with the DO parameter, which is 0,800.
 The research of composition and community structure of copepods in Kakap river estuary, Kubu Raya District, West Borneo was conducted from October to December 2020. The purpose of this study is to determine the composition and the community structure of copepod in Kakap river estuary, Kubu Raya District, West Borneo. This study used a purposive sampling method at four stations. Copepod samples were taken using plankton net. During the research, the total number of copepods that have been identified from 4 stations are 11 species from 3 orders, 4 families and 8 genera. Copepoda that has been obtained has the composition, namly Cyclopoids 5 species, Harpacticoida 3 species, Calanoida 2 species. The copepod density in Kakap river estuary ranged from 7,9-103,3 Ind / l, the diversity index (H ') ranged from 0 to 1.9, the evenness index (E) ranged from 0 - 0,9 and the dominance index (C) ranged from 0,2 - 1. The result of copepod density correlation analysis is that negatively correlated with -1,000 current parameter and positively correlated with the DO parameter, which is 0,800.
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Kassim, Zaleha, Hazwani Hanim Hasnan, Syazleen Zainal, and Nurul Huda Ahmad Ishak. "Report on five species of harpacticoid copepods from vegetative area of Sungai Pulai, Johor." Malaysian Journal of Fundamental and Applied Sciences 14, no. 2 (2018): 284–88. http://dx.doi.org/10.11113/mjfas.v14n2.1095.
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Bottom vegetation is known as preferred habitat for many types of meiofauna such as copepods. The conditions of sea bottom that include vegetation could contribute to the copepod’s assemblage. Being an important diet for fish larvae, information on copepod species promotes effort for conservation of both fish species and marine ecosystem. Nonetheless, identification and taxonomic report on copepods from such areas are still scanty. Samples of copepods were collected by scrapping the uppermost 10cm of sediment of bottom area at Sungai Pulai’s seagrass-bed during low tide. Sediment was decanted to extract the copepods which later be preserved in 5% buffered formalin. Body parts were dissected under microscope and prepared for taxonomic study. All drawings made with the help of Lucida tube were used for comparison with established key of identification. Five families were noted in this study; Ameridae Monard, Lang, Parastenhelia Thompson & A. Scott, Dactylopusiidae Lang, Tisbidae Sars and Diosaccidae Sars. Harpacticoid copepod species described from this study were Ameira sp. (Ameridae Monard, Lang), Parastenhelia sp. (Parastenhelia Thompson & A. Scott), Paradactylopodia sp. (Dactylopusiidae, Lang), Idyanthepusilla (Tisbidae, Sars) and Stenhelia sp. (Diosaccidae Sars). Further study on functional morphology would explain their adaptability to both conditions of sea bottom.
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Ferrari, Frank D., and J. Carel von Vaupel Klein. "Rhabdomoplea, a new superorder for the thaumatopsylloid copepods: the consequence of an alternative hypothesis of copepod phylogeny." Crustaceana 92, no. 2 (2019): 177–88. http://dx.doi.org/10.1163/15685403-00003850.
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Abstract The superorder Rhabdomoplea is established for copepods belonging to the order Thaumatopsylloida. Apomorphies for Rhabdomoplea are an adult prosome, including thoracic somites 1-4, complete at copepodid I, development of the posterior articulation of thoracic somite 7 of males delayed to copepodid IV and of abdominal somite 1 delayed to copepodid V, and absence of a posterior articulation of abdominal somites 2-3 forming with the anal somite a rod-like somite complex as part of the urosome. Rhabdomoplea appears to be the earliest branch of copepods because only thoracic somites 1-4 are broad throughout copepodid development, and thoracic somites 5 and 6 remain narrow. On podopleans and gymnopleans thoracic somite 5 is transformed from the anterior narrow somite to the posterior broad somite during the moult to copepodid II. On gymnopleans thoracic somite 6 also is transformed from the anterior narrow somite to the posterior broad somite but during the moult to copepodid III. Thus rhabdomopleans differ from podopleans in their body architecture as much as podopleans differ from gymnopleans. An alternative and traditional phylogeny that posits gymnopleans as the earliest branch of copepods requires reversal of these two transformations during copepod evolution; this hypothesis is not favoured here because the parsimonious hypothesis of direct, progressive transformations seems reasonable and plausible.
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Santos-Wisniewski, MJ, and O. Rocha. "Spatial distribution and secondary production of Copepoda in a tropical reservoir: Barra Bonita, SP, Brazil." Brazilian Journal of Biology 67, no. 2 (2007): 223–33. http://dx.doi.org/10.1590/s1519-69842007000200007.
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The present paper aims to describe the spatial distribution of zooplankton copepods, their biomass and instantaneous secondary production, in Barra Bonita, a large eutrophic, polymitic reservoir (22° 29' S and 48° 34' W) on the Tietê River, of the Paraná basin. Sampling was carried out during two seasons: dry winter and rainy summer. Species composition, age structure and numerical density of each copepod species population were analyzed at 25 sampling stations. Secondary production was calculated for Copepoda, the dominant group in zooplankton communities, taking Calanoida and Cyclopoida separately. Copepoda represented the largest portion of the total zooplankton biomass, the dominant species being Notodiaptomus iheringi among the Calanoida and Mesocyclops ogunnus and Thermocyclops decipiens among the Cyclopoida. The production of Copepoda was higher during the rainy summer (23.61 mgDW.m-3.d-1 in January 1995) than during the dry winter season (14 mgDW.m-3.d-1 in August 1995), following the general pattern of abundance for the whole zooplankton community. Among the copepods, Cyclopoida production was higher than that of Calanoida, a pattern commonly observed for tropical lakes and reservoirs. Barra Bonita copepods are very productive, but there was a great degree of spatial heterogeneity, related to the physical and chemical conditions, particularly the level of nutrients and also to phytoplankton biomass.
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MNISI, PERAL, and SUSAN M. DIPPENAAR. "Late postnaupliar development of the freshwater copepods Lovenula falicifera and Metadiaptomus colonialis (Calanoida: Diaptomidae) from South Africa." Zootaxa 4877, no. 3 (2020): 468–504. http://dx.doi.org/10.11646/zootaxa.4877.3.5.
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The life cycle of calanoid copepods consists of eggs hatching into nauplii (6 stages) which then moult into copepodids (5 stages), followed by the final moult into the adult female and male. The family Diaptomidae contains two subfamilies, Diaptominae and Paradiaptominae, with paradiaptomids almost exclusively consisting of African taxa. The copepodid stages III, IV and V were described for some freshwater diaptomine genera (i.e., Eudiaptomus Kiefer, 1932, Aglaodiaptomus Light, 1938, Skistodiaptomus Light, 1939, Leptodiaptomus Light, 1938, Megadiaptomus Kiefer, 1936 and Diaptomus Westwood, 1836). Copepods collected from Turfloop Dam, South Africa, with a plankton net were fixed and preserved in 70% ethanol. Calanoid copepods were studied under stereo- and light microscopes, using the wooden slide technique and features drawn. Examined specimens were identified as the copepodid stages of two African species, Lovenula falcifera (Lovén, 1845) and Metadiaptomus colonialis (van Douwe, 1914). Copepodids of the two species can be distinguished by their body size and the structure and size of the maxillipeds. The description and illustrations of three postnaupliar stages (CoIII, CoIV and CoV) are provided for both species. The identification of different stages is based on the number of urosomites, antennule development, the segmentation of legs 1–4, and the development of the fifth leg. These copepodids are compared with those of other described diaptomid genera.
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Morales-Ramírez, Alvaro, Eduardo Suarez-Morales, Marco Corrales-Ugalde, and Octavio Esquivel Garrote. "Diversity of the free-living marine and freshwater Copepoda (Crustacea) in Costa Rica: a review." ZooKeys 457 (November 25, 2014): 15–33. https://doi.org/10.3897/zookeys.457.6820.
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The studies on marine copepods of Costa Rica started in the 1990's and focused on the largest coastal-estuarine systems in the country, particularly along the Pacific coast. Diversity is widely variable among these systems: 40 species have been recorded in the Culebra Bay influenced by upwelling, northern Pacific coast, only 12 in the Gulf of Nicoya estuarine system, and 38 in Golfo Dulce, an anoxic basin in the southern Pacific coast of the country. Freshwater environments of Costa Rica are known to harbor a moderate diversity of continental copepods (25 species), which includes 6 calanoids, 17 cyclopoids and only two harpacticoids. Of the +100 freshwater species recorded in Central America, six are known only from Costa Rica, and one appears to be endemic to this country. The freshwater copepod fauna of Costa Rica is clearly the best known in Central America. Overall, six of the 10 orders of Copepoda are reported from Costa Rica. A previous summary by 2001 of the free-living copepod diversity in the country included 80 marine species (67 pelagic, 13 benthic). By 2009, the number of marine species increased to 209: 164 from the Pacific (49% of the copepod fauna from the Eastern Tropical Pacific) and 45 from the Caribbean coast (8% of species known from the Caribbean Basin). Both the Caribbean and Pacific species lists are growing. Additional collections of copepods at Cocos Island, an oceanic island 530 km away of the Pacific coast, have revealed many new records, including five new marine species from Costa Rica. Currently, the known diversity of marine copepods of Costa Rica is still in development and represents up to 52.6% of the total marine microcrustaceans recorded in the country. Future sampling and taxonomic efforts in the marine habitats should emphasize oceanic environments including deep waters but also littoral communities. Several Costa Rican records of freshwater copepods are likely to represent undescribed species. Also, the biogeographic relevance of the inland copepod fauna of Costa Rica requires more detailed surveys.
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Jeyam, Gomathi, and Ramanibai R*. "Molecular characterization and phylogenetic analysis of cyclopoid copepod Mesocyclops leuckarti using mtCOI." International Journal of Bioassays 6, no. 04 (2017): 5365. http://dx.doi.org/10.21746/ijbio.2017.04.008.
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Copepods are the most abundant metazoan zooplankton amongst multicellular animals. The present study was performed to establish the sequence variation of partial mitochondrial Cytochrome c Oxidase I gene (COI) from Mesocyclops leuckarti collected from the Retteri Lake, Chennai in order to identify and describe their genetic divergence along with the phylogenetic relatedness with other species. DNA of individual M. leuckarti was extracted and the partial mitochondrial COI gene was successfully amplified using the universal primers LCO-1490 and HCO-2198. A 576bp partial mitochondrial COI gene sequence was obtained. Analysis of partial COI sequences of M. leuckarti exposed 93% similarity amongst all the individual of copepods selected from Genbank. The obtained COI sequences of Cyclopoid copepod was confirmed with BLAST analysis. Phylogenetic analysis of M. leuckarti along with selected out groups from different taxa level further supports the clarity and maintained the authentic of taxonomy up to the subclass level: Copepoda. The results showed that, the COI barcoding of cyclopoid copepod species could be distinguished from the others very clearly. Thus, it strongly indicated that COI may be a useful construction of a comprehensive DNA barcode database for copepods inhabiting the freshwater bodies in Chennai.
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Muschiol, Daniel, Mirjana Marković, Ilka Threis, and Walter Traunspurger. "Predator-prey relationship between the cyclopoid copepod Diacyclops bicuspidatus and a free-living bacterivorous nematode." Nematology 10, no. 1 (2008): 55–62. http://dx.doi.org/10.1163/156854108783360203.
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Abstract The potential of copepods as predators of free-living nematodes was tested by presenting Diacyclops bicuspidatus, a common holarctic cyclopoid copepod, with Panagrolaimus sp. as prey in the laboratory. Diacyclops bicuspidatus readily fed on nematodes of all size classes, including prey longer than itself. No size preference was observed. Handling times varied between a few seconds and several minutes, depending on the size of the prey. At different prey densities, the feeding rates of D. bicuspidatus followed a type II functional response. Starved D. bicuspidatus consumed up to 45.1 nematodes in 2 h, equivalent to 43.5% of the copepod's body mass. Indications that nematophagous nutrition is common among freshwater copepods are discussed.
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Kang, Jung-Hoon, Oh-Youn Kwon, Sang Hee Hong, and Won Joon Shim. "Can Zooplankton Be Entangled by Microfibers in the Marine Environment?: Laboratory Studies." Water 12, no. 12 (2020): 3302. http://dx.doi.org/10.3390/w12123302.
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We investigated the probability of copepod entanglement in microfibers in a laboratory experiment. This experiment was inspired by an accidental observation of entangled copepods with microfibers during isolating copepods for grazing experiments. The exposure of microfibers to copepods was designed by applying conditions similar to environmentally relevant concentrations of microfibers to zooplankton in the Yellow Sea as well as highly elevated concentrations of microfibers compared to the previously reported maximum natural concentration. Copepod entanglement in microfibers was reproduced in laboratory. The entanglement was not observed in the condition which simulated the environmental scenario of copepods outnumbering microfibers observed in the Yellow Sea, while it occurred inconsistently in the conditions of the maximum and 10-fold maximum natural concentrations of microfibers. However, consistent entanglement of copepods by microfibers was found in the 100-fold maximum environmental concentration of microfibers. These results suggest that copepod entanglement by microfibers can happen accidentally under the maximum natural concentration of microfibers occurring in the marine environment; however, copepods are likely to be entangled in microfibers consistently if copepods encounter highly enhanced concentration of microfibers.
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Aganesova, L. O. "Production characteristics of the copepods Arctodiaptomus salinus and Calanipeda aquaedulcis fed with a mixture of microalgae Dinophyceae and Prymnesiophyceae." Marine Biological Journal 5, no. 2 (2020): 3–11. http://dx.doi.org/10.21072/mbj.2020.05.2.01.
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The ubiquitous copepod species Arctodiaptomus salinus (Daday, 1885) and Calanipeda aquaedulcis (Krichagin, 1873) are important components of food chains of numerous fresh- and saltwater areas. These copepods are suitable for feeding larvae of both marine and freshwater fish species; however, influence of nutrition on the production characteristics of these species is not well understood. Previously we determined that monocultures of microalgae Dinophyceae and Prymnesiophyceae are optimal feeding objects for egg production by females of A. salinus and C. aquaedulcis, survival rate, and development time of these copepods throughout ontogenesis. The aim of this work was to determine the production characteristics of copepods A. salinus and C. aquaedulcis under optimal temperature conditions depending on the model of the feeding with a mixture of microalgae Dinophyceae and Prymnesiophyceae. The highest survival rates of A. salinus from the naupliar stage to the adult one (93–95 %) were observed when copepods were fed with a monoculture of microalga Isochrysis galbana (Parke, 1949) or a mixture I. galbana + Prorocentrum cordatum (Ostenfeld) J. D. Dodge, 1975; the shortest development time (19 days) – when copepods were fed with a mixture of three microalgae I. galbana + P. cordatum + Prorocentrum micans (Ehrenberg, 1834). The shortest development time of C. aquaedulcis from the naupliar stage to the adult one (13 days) was observed when copepods were fed with a mixture of microalgae I. galbana + P. cordatum. The shortest duration of the naupliar stage of development of both copepod species was observed when their diet included I. galbana as a monoculture or one of mixture components. During the copepodit stage, the pattern remains the same, only with P. cordatum. The maximum absolute fecundity of C. aquaedulcis reached 24 eggs per female (I. galbana), of A. salinus – 16 eggs per female (P. cordatum). Egg hatching of C. aquaedulcis when being fed with both monocultures of microalgae P. cordatum and I. galbana and with their mixture reached 100 %. The highest egg hatching rate for A. salinus was reached only when copepod females were fed with a mixture of microalgae I. galbana + P. micans.
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Köster, Marion, and Gustav-Adolf Paffenhöfer. "On the Predation of Doliolids (Tunicata, Thaliacea) onCalanoid Copepods." Journal of Marine Science and Engineering 10, no. 9 (2022): 1293. http://dx.doi.org/10.3390/jmse10091293.
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The main goal of this contribution was to determine the effect of predation of the often abundant to dominant doliolid Dolioletta gegenbauri (Tunicata, Thaliacea) on the abundance of co-occurring planktonic copepods by feeding on their eggs. Previous oceanographic investigations revealed that doliolids had ingested eggs of small calanoid copepods. The ecological significance of such feeding could not be quantified completely because the environmental abundance of such eggs was not known. In this study, the eggs and nauplii of the neritic calanoid Paracalanus quasimodo (Crustacea, Copepoda) were offered to gonozooids and phorozooids of D. gegenbauri with a 6–6.5 mm length together with three species of phytoplankton; i.e., simulating diet conditions on the shelf. We hypothesized that copepod eggs of a similar size as food particles would be readily ingested whereas small nauplii, which could escape, would hardly be eaten by the doliolids. Our results revealed that doliolids have the potential to control small calanoids by ingesting their eggs at high rates but not their nauplii or later stages. Late copepodid stages and adults of co-occurring calanoid species could cause less mortality because they prey less on such eggs than doliolids of a similar weight. However, certain abundant omnivorous calanoid species with pronounced perception and/or capture abilities can prey successfully on the nauplii of small calanoids.
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Nie, P., and C. R. Kennedy. "Infection dynamics of larval Bothriocephalus claviceps in Cyclops vicinus." Parasitology 106, no. 5 (1993): 503–9. http://dx.doi.org/10.1017/s0031182000076800.
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SUMMARYThe infection dynamics of Cyclops vicinus by the larvae of Bothriocephalus claviceps were studied experimentally. The mean number of procercoids/copepod rose to a plateau of approximately 14 as the density of eggs increased, whilst the number of copepods surviving decreased correspondingly. Copepods exposed to eggs of B. claviceps survived less well than controls, and those exposed to a higher density of eggs survived less well than those to a lower density. The mean number of parasites/copepod and the mortality of copepods were found to increase with the increasing time of exposure to eggs even when egg density was constant. These two parameters were also found to differ between gravid female copepods and unsexed young copepods. Young copepods suffered a higher parasite burden and thus a higher mortality, indicating that there are age or developmental-stage related differences in susceptibility of copepods to infection.
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Malzahn, Arne M., Nicole Aberle-Malzahn, Katherina Schoo, and Maarten Boersma. "Culture conditions affect the nutritional value of the copepod Acartia tonsa." Journal of Agricultural and Marine Sciences [JAMS] 20 (January 1, 2015): 40. http://dx.doi.org/10.24200/jams.vol20iss0pp40-46.
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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.
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Koguchi, Yunosuke, Koki Tokuhiro, Carin J. Ashjian, Robert G. Campbell, and Atsushi Yamaguchi. "Body length, dry and ash-free dry weights, and developmental changes at each copepodid stage in five sympatric mesopelagic aetideid copepods in the western Arctic Ocean." Crustaceana 96, no. 2 (2023): 113–29. http://dx.doi.org/10.1163/15685403-bja10272.
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Abstract Aetideid copepods dominate the mesopelagic layer of the Arctic Ocean and play an important role in the vertical material flux and biodiversity. However, little information about the lengths and weights of their copepodids is available. In this study, we collected five sympatric aetideid copepods, Chiridius obtusifrons Sars G.O., 1902, Gaetanus tenuispinus (Sars G.O., 1900), Gaetanus brevispinus (Sars G.O., 1900), Aetideopsis multiserrata (Wolfenden, 1904), and Aetideopsis rostrata Sars G.O., 1903, from the Arctic Ocean and examined their body lengths, dry and ash-free dry weights, and developmental growths at each copepodid stage. Highly significant length-weight relationships were obtained among copepodids for all species. Within genera, individuals of the same length were heavier at shallower depths. This may result from the greater nutritional availability to species within genera inhabiting shallower depths. Common to all species, the organic content (ash-free dry weight per dry weight) was high for the early copepodid stages. This may be due to the residual organic content of lipid-rich eggs retained in the non-feeding nauplii. The largest growth in females occurred at C5/C6, whereas the largest growth in males occurred at C4/C5, as determined by moult increment and proportion of growth in weight. These sex differences in weight growth could be due to the degeneration of the feeding appendage and cessation of feeding in C6 males of aetideid copepods.
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Ayón Dejo, Patricia, Elda Luz Pinedo Arteaga, Anna Schukat, et al. "Zooplankton community succession and trophic links during a mesocosm experiment in the coastal upwelling off Callao Bay (Peru)." Biogeosciences 20, no. 5 (2023): 945–69. http://dx.doi.org/10.5194/bg-20-945-2023.
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Abstract. The Humboldt Current Upwelling System (HCS) is the most productive eastern boundary upwelling system (EBUS) in terms of fishery yield on the planet. EBUSs are considered hotspots of climate change with predicted expansion of mesopelagic oxygen minimum zones (OMZs) and related changes in the frequency and intensity of upwelling of nutrient-rich, low-oxygen deep water. To increase our mechanistic understanding of how upwelling impacts plankton communities and trophic links, we investigated mesozooplankton community succession and gut fluorescence, fatty acid and elemental compositions (C, N, O, P), and stable isotope (δ13C, δ15N) ratios of dominant mesozooplankton and microzooplankton representatives in a mesocosm setup off Callao (Peru) after simulated upwelling with OMZ water from two different locations and different N:P signatures (moderate and extreme treatments). An oxycline between 5 and 15 m with hypoxic conditions (<50 µmol L−1) below ∼10 m persisted in the mesocosms throughout the experiment. No treatment effects were determined for the measured parameters, but differences in nutrient concentrations established through OMZ water additions were only minor. Copepods and polychaete larvae dominated in terms of abundance and biomass. Development and reproduction of the dominant copepod genera Paracalanus sp., Hemicyclops sp., Acartia sp., and Oncaea sp. were hindered as evident from accumulation of adult copepodids but largely missing nauplii. Failed hatching of nauplii in the hypoxic bottom layer of the mesocosms and poor nutritional condition of copepods suggested from very low gut fluorescence and fatty acid compositions most likely explain the retarded copepod development. Correlation analysis revealed no particular trophic relations between dominant copepods and phytoplankton groups. Possibly, particulate organic matter with a relatively high C:N ratio was a major diet of copepods. C:N ratios of copepods and polychaetes ranged 4.8–5.8 and 4.2–4.3, respectively. δ15N was comparatively high (∼13 ‰–17 ‰), potentially because the injected OMZ source water was enriched in δ15N as a result of anoxic conditions. Elemental ratios of dinoflagellates deviated strongly from the Redfield ratio. We conclude that opportunistic feeding of copepods may have played an important role in the pelagic food web. Overall, projected changes in the frequency and intensity of upwelling hypoxic waters may make a huge difference for copepod reproduction and may be further enhanced by varying N:P ratios of upwelled OMZ water masses.
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Tuno, Nobuko, Tran Vu Phong, and Masahiro Takagi. "Climate Change May Restrict the Predation Efficiency of Mesocyclops aspericornis (Copepoda: Cyclopidae) on Aedes aegypti (Diptera: Culicidae) Larvae." Insects 11, no. 5 (2020): 307. http://dx.doi.org/10.3390/insects11050307.
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(1) Dengue is the most spread mosquito-borne viral disease in the world, and vector control is the only available means to suppress its prevalence, since no effective treatment or vaccine has been developed. A biological control program using copepods that feed on mosquito larvae has been practiced in Vietnam and some other countries, but the application of copepods was not always successful. (2) To understand why the utility of copepods varies, we evaluated the predation efficiency of a copepod species (Mesocyclops aspericornis) on a vector species (Aedes aegypti) by laboratory experiments under different temperatures, nutrition and prey-density conditions. (3) We found that copepod predation reduced intraspecific competition among Aedes larvae and then shortened the survivor’s aquatic life and increased their pupal weight. In addition, the predatory efficiency of copepods was reduced at high temperatures. Furthermore, performance of copepod offspring fell when the density of mosquito larvae was high, probably because mosquito larvae had adverse effects on copepod growth through competition for food resources. (4) These results suggest that the increase in mosquitoes will not be suppressed solely by the application of copepods if the density of mosquito larvae is high or ambient temperature is high. We need to consider additional control methods in order to maintain the efficiency of copepods to suppress mosquito increase.
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Conley, David C., and Mark A. Curtis. "Effects of temperature and photoperiod on the duration of hatching, swimming, and copepodid survival of the parasitic copepod Salmincola edwardsii." Canadian Journal of Zoology 71, no. 5 (1993): 972–76. http://dx.doi.org/10.1139/z93-128.
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We conducted laboratory experiments to test whether various temperature and photoperiod regimes had any effect on the duration of egg hatching, swimming activity, and copepodid survival in the parasitic copepod Salmincola edwardsii, commonly found on brook trout (Salvelinus fontinalis). Pairs of egg sacs were removed from adult female copepods; one of each pair was exposed to a different photoperiod than the other, at the same temperature. Experiments were conducted at 8, 12, 16, and 20 °C. Temperature had a significant effect on the duration of copepodid swimming activity and survival, and the onset of egg sac hatching was directly related to increasing water temperature. However, hatching duration and hatching success were not affected by temperature over the range tested. Photoperiod had no effect on hatching duration, hatching success, swimming activity, or copepodid survival. Our findings indicate that S. edwardsii copepodids can swim and survive for more than 2 weeks; much longer than the 2 days customarily reported in the literature. This must be accounted for in the development of strategies to control transmission.
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Hong, Guo-Kai, and Kwee Siong Tew. "The Advantages of Inorganic Fertilization for the Mass Production of Copepods as Food for Fish Larvae in Aquaculture." Life 12, no. 3 (2022): 441. http://dx.doi.org/10.3390/life12030441.
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Copepods are commonly used as live feed for cultured fish larvae, but the current mass production method using organic fertilizers cannot meet the market demand for copepods. We evaluated the feasibility of applying an inorganic fertilization method, which is currently in use in freshwater and marine larviculture, to the mass production of copepods. For 30 days, and with five replicates of each treatment, we made comparative daily measurements of various parameters of (1) copepod cultures fertilized with commercially available condensed fish solubles (organic fertilization) and (2) other cultures in which the concentration of inorganic phosphorus was maintained at 100 μg P L−1 and that of inorganic nitrogen at 700 μg N L−1 (inorganic fertilization). With inorganic fertilization, pH fluctuated over a smaller range and much less filamentous algae grew in the tanks. The mean production of copepod nauplii over the course of the study was similar between the two treatments, but the combined density of copepodites and adult copepods was significantly higher with inorganic fertilization. Compared to commercial zooplankton products, copepods cultured with inorganic fertilization were smaller, were mixed with fewer (almost none) non-copepod contaminants, were also pathogen-free, and could be produced at the cheapest cost per unit output. Based on these results, we conclude that the inorganic fertilization method can profitably be adopted by commercial copepod producers to meet the demand from fish farmers, especially for small-sized copepods.
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Cheng, Yu-Rong, Ching-Yi Lin, and Jr-Kai Yu. "Embryonic and post-embryonic development in the parasitic copepod Ive ptychoderae (Copepoda: Iviidae): Insights into its phylogenetic position." PLOS ONE 18, no. 3 (2023): e0281013. http://dx.doi.org/10.1371/journal.pone.0281013.
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Parasitic copepods are frequently discovered in many marine animals, and they exhibit great species diversity with remarkable morphological adaptations to their parasitic lifestyle. Similar to their free-living relatives, parasitic copepods usually develop through complex life cycle, but they eventually transform into a modified adult form with reduced appendages. Although the life cycle and distinct larval stages have been described in a few species of parasitic copepods, particularly those infecting commercially valuable marine animals (such as fishes, oysters, and lobsters), very little is known about the developmental process of the species that transformed into extremely simplified adult body plan. This paucity also causes some difficulties when investigating the taxonomy and phylogeny of this kind of parasitic copepods. Here we describe the embryonic development and a series of sequential larval stages of a parasitic copepod, Ive ptychoderae, which is a vermiform endoparasite living inside the hemichordate acorn worms. We devised laboratory regimes that enable us raising large quantity of embryos and free living larvae, and obtaining post-infested I. ptychoderae samples from the host tissues. Using defined morphological features, the embryonic development of I. ptychoderae can be categorized into eight stages (1-, 2-, 4-, 8-, 16- cell stages, blastula, gastrula, and limb bud stages) and the post-embryonic development comprises six larval stages (2 naupliar and 4 copepodid stages). Based on the comparisons of morphological characters in the nauplius stage, our results provide evidence to support that the Ive-group is more closely related to the Cyclopoida, which represents one of the two major clades that contain many highly transformed parasitic copepods. Thus, our results help to resolve the problematic phylogenetic position of the Ive-group in previous study based on analysis using 18S rDNA sequences. Combining with more molecular data, future comparative analyses on the morphological features of copepodid stages will further refine our understanding of the phylogenetic relationships of parasitic copepods.
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Hong, Guo-Kai, Jimmy Kuo, and Kwee Siong Tew. "Iron Fertilization Can Enhance the Mass Production of Copepod, Pseudodiaptomus annandalei, for Fish Aquaculture." Life 13, no. 2 (2023): 529. http://dx.doi.org/10.3390/life13020529.
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Copepods are proven nutritious food sources for the mariculture/larviculture industry, however, unreliable methods for mass production of copepods are a major bottleneck. In this study, we modified a previously reported inorganic fertilization method (N: 700 μg L−1 and P: 100 μg L−1) by the addition of iron (Fe: 10 μg L−1, using FeSO4·7H2O) (+Fe treatment) and compared its suitability for copepod culture (Pseudodiaptomus annandalei) to the original method (control). The experiment was conducted outdoors in 1000 L tanks for 15 days. The addition of iron prolonged the growth phase of the phytoplankton and resulted in the production of significantly more small phytoplankton (0.45–20 μm, average 2.01 ± 0.52 vs. 9.03 ± 4.17 µg L−1 in control and +Fe, respectively) and adult copepods (control: 195 ± 35, +Fe: 431 ± 109 ind L−1), whereas copepodid-stage was similar between treatments (control: 511 ± 107 vs. +Fe: 502 ± 68 ind L−1). Although adding iron increased the cost of production by 23% compared to the control, the estimated net profit was 97% greater. We concluded that inorganic fertilization, with the addition of iron (Fe: 10 μg L−1), could be an effective method for the mass production of copepods for larviculture.
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Wagner, Zachary, John H. Costello, and Sean P. Colin. "Fluid and Predator-Prey Interactions of Scyphomedusae Fed Calanoid Copepods." Fluids 5, no. 2 (2020): 60. http://dx.doi.org/10.3390/fluids5020060.
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The feeding current of scyphomedusae entrains and transports surrounding fluids and prey through trailing tentacles to initiate encounters with prey. After contact, most prey are retained for ingestion. However, the probability that a contact will occur depends on several factors including capture surface morphology, prey size and behavior. We examined how hydrodynamics, capture surface morphology and prey behavior affect the capture probability of copepods. To do this, we documented medusa-copepod interactions of four species of scyphomedusae (two semeostomes and two rhizostomes) possessing different capture surface morphologies. We tracked the movement and behavior of entrained copepods throughout the feeding process to quantify prey behavior effects upon capture efficiency (# captures/# encounters). The feeding currents generated by all the medusan species generated fluid shear deformation rates well above the detection limits of copepods. Despite strong hydrodynamic signals, copepod behavior was highly variable and only 58% of the copepods reacted to entrainment within feeding currents. Furthermore, copepod behavior (categorized as no reaction, escape jump or adjustment jump) did not significantly affect the capture efficiency. The scale and complexity of the feeding current generated by scyphomedusae may help explain the poor ability of copepods to avoid capture.
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Khanaychenko, A. N. "How diatom Cylindrotheca closterium vanquish invasive copepod Oithona davisae." Marine Biological Journal 3, no. 3 (2018): 77–85. http://dx.doi.org/10.21072/mbj.2018.03.3.08.
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Some diatoms are rich food for herbivorous copepods, while others are toxic for their recruitment. No negative effect of diatom Cylindrotheca closterium was ever observed for copepods, and some estuarine copepods preferred it as a food. Data on grazing diatoms by abundant now in the Black Sea coastal waters invasive copepod Oithona davisae are still contradictory. Interaction of O. davisae and C. closterium, both having high colonizing potential and both typical for coastal waters, was studied in experimental culture. Two weeks after inoculation of C. closterium the cultured O. davisae was drastically fouled by globulous conglomerates of diatom cells. Diatom cells in “colonies” on copepod exoskeleton were interconnected by means of adhesive substances at one of their flexible ends at the point-wise areas at various parts of copepods exoskeleton, and the opposite flexible ends performed various circular roll-over fan-shaped movements around the axis passing through the point of their attachment. “Colonies” behaved as integrated aggressive organisms against any approaching flagellate and prevented normal locomotion of copepods. Herein we present the first report on epizoic behavior of C. closterium: quick disastrous colonization of alive copepods O. davisae by diatom “colonies” led to total extinction of cyclopoid experimental population while alive diatoms formed dense network on copepods degenerative tissues.
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Beaumont, K. L., and G. W. Hosie. "Mesoscale distribution and abundance of four pelagic copepod species in Prydz Bay." Antarctic Science 9, no. 2 (1997): 121–33. http://dx.doi.org/10.1017/s0954102097000163.
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Knowledge of copepod abundance and distribution has been limited, particularly in the Indian Ocean sector, as the use of coarse sampling gear has meant that copepods were frequently lost from the catch. This study analyses samples obtained from Prydz Bay using a fine mesh (300 μm) Rectangular Midwater Trawl (RMT1) net during summer 1992–93. Results demonstrate that a net of mesh 4.5 mm used in previous studies underestimates total copepod abundance by a factor of 38. The abundance of the smaller species has been underestimated the most. New estimates of copepod biomass indicate that copepods represent approximately 27% of krill biomass. Copepod and krill distributions are shown to be discrete at 82.4% dissimilarity. Mean temperature accounted for 33.6% of the variation in copepod distribution while two of the species showed a slight correlation with chlorophyll a pigment data. These results highlight the numerical importance of copepods and the species' distributions in the East Antarctic marine ecosystem.
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Hanzelová, V. "Proteocephalus neglectus as a possible indicator of changes in the ecological balance of aquatic environments." Journal of Helminthology 66, no. 1 (1992): 17–24. http://dx.doi.org/10.1017/s0022149x00012517.
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ABSTRACTIn an environment seriously impaired by human interference (draining the reservoir), ecological relationships in a community of copepods and their impact on the transmission of the tapeworm Proteocephalus neglectus La Rue. 1911 were studied. The impairment of the environment resulted in changes in the species composition of the copepod community and in the increased diversity of the copepod species, as well as in a multiple inversion of the dominant and subdominant relationships of the two most numerous copepod species (Cyclops vicinus and Eudiaptomus zachariasi). The structure of the developmental stages of the copepod community, the seasonal dynamics of the number of copepods and the abundance of P. neglectus procercoids have changed. The predominant species in the copepod community and the most susceptible intermediate host of P. neglectus (C. vicinus) was not infected. The infection of copepods decreased by 95% and that of the definitive hosts (Oncorhynchus mykiss) by 97·5% compared with the index values recorded in the previous year.
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Toullec, Jordan, Alice Delegrange, Adélaïde Perruchon, et al. "Copepod Feeding Responses to Changes in Coccolithophore Size and Carbon Content." Journal of Marine Science and Engineering 10, no. 12 (2022): 1807. http://dx.doi.org/10.3390/jmse10121807.
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Phytoplankton stoichiometry and cell size could result from both phenology and environmental change. Zooplankton graze on primary producers, and this drives both the balance of the ecosystem and the biogeochemical cycles. In this study, we performed incubations with copepods and coccolithophores including different prey sizes and particulate carbon contents by considering phytoplankton biovolume concentration instead of chlorophyll a level (Chl a) as is usually performed in such studies. The egestion of fecal pellet and ingestion rates were estimated based on a gut fluorescence method. The latter was calibrated through the relationship between prey Chl a level and the biovolume of the cell. Chl a/biovolume ratio in phytopkanton has to be considered in the copepod gut fluorescent content method. Both coccolithophore biovolume and particulate inorganic/organic carbon ratios affect the food foraging by copepods. Finally, we observed a non-linear relationship between ingestion rates and fecal pellet egestion, due to the presence of calcite inside the copepod’s gut. These results illustrate that both prey size and stoichiometry need to be considered in copepod feeding dynamics, specifically regarding the process leading to the formation of fecal pellets.
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McFarlane, G. A., and R. J. Beamish. "Climatic Influence Linking Copepod Production with Strong Year-Classes in Sablefish, Anoplopoma fimbria." Canadian Journal of Fisheries and Aquatic Sciences 49, no. 4 (1992): 743–53. http://dx.doi.org/10.1139/f92-083.
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Stomach contents from first-feeding larval sablefish (Anoplopoma fimbria) comprised mainly calanoid copepods. Along the west coast of Vancouver Island, these copepods were the dominant zooplankton at the depth that sablefish larvae developed. We propose that strong year-classes in sablefish populations occur when there is exceptional production of copepods. The periods of exceptional copepod production appear to be correlated with climate and ocean conditions.
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JOHNSSON, RODRIGO, and ELIZABETH NEVES. "Siphonostomatoid copepods (Crustacea) associated with marine invertebrates and algae in Brazil: a review and future considerations." Zoosymposia 8, no. 1 (2012): 69–80. http://dx.doi.org/10.11646/zoosymposia.8.1.10.
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In Brazil, knowledge on copepods of the order Siphonostomatoida dates back to the late 1800s, with the earliest record concerning parasitic copepods of fish. In contrast, the first record in Brazil of a copepod associated with an unknown marine invertebrate did not appear until 1988, with further studies on this copepod group occurring only during the last 15 years. The aim of this paper is to summarize the knowledge on the diversity of the siphonostome copepods, focusing on the associates of marine invertebrates, and to add new data on the distribution of known species and on the utilization of host species. Finally, an evaluation is carried out on the results and the effort expended during this period, and some objectives are proposed for improving the knowledge of the siphonostome copepods associated with marine invertebrates in Brazil.
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Sasaki, Hiroko, Kohei Matsuno, Amane Fujiwara, et al. "Distribution of Arctic and Pacific copepods and their habitat in the northern Bering and Chukchi seas." Biogeosciences 13, no. 15 (2016): 4555–67. http://dx.doi.org/10.5194/bg-13-4555-2016.
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Abstract. The advection of warm Pacific water and the reduction in sea ice in the western Arctic Ocean may influence the abundance and distribution of copepods, a key component of food webs. To quantify the factors affecting the abundance of copepods in the northern Bering and Chukchi seas, we constructed habitat models explaining the spatial patterns of large and small Arctic and Pacific copepods separately. Copepods were sampled using NORPAC (North Pacific Standard) nets. The structures of water masses indexed by principle component analysis scores, satellite-derived timing of sea ice retreat, bottom depth and chlorophyll a concentration were integrated into generalized additive models as explanatory variables. The adequate models for all copepods exhibited clear continuous relationships between the abundance of copepods and the indexed water masses. Large Arctic copepods were abundant at stations where the bottom layer was saline; however they were scarce at stations where warm fresh water formed the upper layer. Small Arctic copepods were abundant at stations where the upper layer was warm and saline and the bottom layer was cold and highly saline. In contrast, Pacific copepods were abundant at stations where the Pacific-origin water mass was predominant (i.e. a warm, saline upper layer and saline and a highly saline bottom layer). All copepod groups showed a positive relationship with early sea ice retreat. Early sea ice retreat has been reported to initiate spring blooms in open water, allowing copepods to utilize more food while maintaining their high activity in warm water without sea ice and cold water. This finding indicates that early sea ice retreat has positive effects on the abundance of all copepod groups in the northern Bering and Chukchi seas, suggesting a change from a pelagic–benthic-type ecosystem to a pelagic–pelagic type.
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MacKinnon, Rebecca B., Jannes Landschoff, and Charles L. Griffiths. "Rediscovery and first South African records of the parasitic copepod Cancerilla oblonga Bartsch, 1975 (Crustacea, Cancerillidae)." African Invertebrates 57, no. (2) (2016): 105–9. https://doi.org/10.3897/AfrInvertebr.57.9775.
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The parasitic copepod Cancerilla oblonga, previously know only from the single holotype female collected from Luderitz Bay, Namibia, is rediscovered in Cape Town, South Africa, where it parasitises the brittlestar Amphiura capensis. The first photographic and SEM images of this species are presented and prevalence rates estimated. Of 240 hosts examined, 25 (=10.42%) were infected, of these 7.53% carried a single copepod, 2.09% two copepods and 0.84% three copepods. This discovery is the first record of any siphonostomatoid copepod infecting an invertebrate host in South Africa.
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MacKinnon, Rebecca B., Jannes Landschoff, and Charles L. Griffiths. "Rediscovery and first South African records of the parasitic copepod Cancerilla oblonga Bartsch, 1975 (Crustacea, Cancerillidae)." African Invertebrates 57, no. (2) (2016): 105–9. https://doi.org/10.3897/afrinvertebr.57.9775.
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The parasitic copepod Cancerilla oblonga, previously know only from the single holotype female collected from Luderitz Bay, Namibia, is rediscovered in Cape Town, South Africa, where it parasitises the brittlestar Amphiura capensis. The first photographic and SEM images of this species are presented and prevalence rates estimated. Of 240 hosts examined, 25 (=10.42%) were infected, of these 7.53% carried a single copepod, 2.09% two copepods and 0.84% three copepods. This discovery is the first record of any siphonostomatoid copepod infecting an invertebrate host in South Africa.
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Hirai, J., K. Yamazaki, K. Hidaka, S. Nagai, Y. Shimizu, and T. Ichikawa. "Characterization of diversity and community structure of small planktonic copepods in the Kuroshio region off Japan using a metabarcoding approach." Marine Ecology Progress Series 657 (January 7, 2021): 25–41. http://dx.doi.org/10.3354/meps13539.
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Small copepods are important prey for fish larvae in the Kuroshio region off southern Japan. However, revealing entire community structures of small copepods is difficult using conventional methods. We applied a metabarcoding method to size-fractionated community samples of epipelagic copepods (small: 0.1-0.5 mm, medium: 0.5-1.0 mm, and large: 1.0-2.0 mm). Samples were collected from 2013 to 2016 from the shoreward (Kuroshio Slope, KS) and oceanic (Kuroshio Gyre, KG) sides of the Kuroshio Current at 138° E; the results were compared with those in the center of the subtropical gyre (SG). The KS and KG sites showed both spatial differences and seasonal changes, with distinct differences between winter-spring and summer-autumn in each size-fractionated community. Water temperature markedly influenced copepod diversity and community structure, especially in the small size fraction. Warm-water species in the SG intruded into the Kuroshio regions during high-temperature periods, leading to high diversity in summer-autumn. Inter-annual environmental variations influenced by temperature and productivity were evident in KS, leading to clear changes in the sequence proportions of dominant small copepods including Paracalanus sp. and immature stages of the large copepod Calanus sinicus. Immature stages of medium/large copepods formed a substantial proportion of small-copepod communities in the Kuroshio regions (KS: 28.8%; KG: 24.7%; SG: 11.9%; based on average proportions of sequence reads). Because of their ecological importance and sensitivity to environmental changes, monitoring communities of small copepods with high taxonomic resolution may provide further insights into marine ecosystems, including fish recruitment, in the Kuroshio region.
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Kovaleva, N. N. "CHOROLOGIC ANALYSIS OF THE MARINE COPEPODS (COPEPODA) PARASITIC ON FISHES OF VIETMAM." A.I. Kurentsov's Annual Memorial Meetings 34 (August 28, 2023): 217–23. http://dx.doi.org/10.25221/kurentzov.34.17.
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Nowadays 72 species of copepods (Copepoda) parasitizing marine fish in Vietnam have been identified. The chorological analysis of marine parasitic copepods allows to distinguish nine groups of species: widespread Atlantic-Pacific (23 species), Indo-West- Pacific (without Oceania) (25 species), Indo-West-Pacific with a broken range (11 species), Western Pacific (including Oceania) (1 species), Japanese-Malay (2 species), Philippine- Malay (1 species), Chinese-Australian (1 species), Chinese-Japanese (4 species) and endemics of Vietnam (4 species). The majority of Vietnamese marine copepods belong to the Indo-West- Pacific (34.7% species), and widespread Atlantic-Pacific groups (34.7% and 31.9% species, respectively). A preliminary comparison of the species composition of copepods from Japan, Taiwan, the Philippines, and Vietnam was made. Keywords: marine copepods, distribution, South
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Korzhavina, Oksana A., Darya Y. Grishina, Xingru Chen, Diego Fontaneto, and Viatcheslav N. Ivanenko. "Diving into Diversity: Copepod Crustaceans in Octocoral Associations." Diversity 15, no. 11 (2023): 1140. http://dx.doi.org/10.3390/d15111140.
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This research provides an extensive analysis of the biodiversity and distribution patterns of copepod crustaceans associated with octocoral species. A comprehensive dataset comprising 966 records pertaining to 233 copepod species, encompassing 54 genera, 18 families, and 3 orders, was compiled from 92 scientific papers published between 1858 and 2023, and updated as open data to GBIF. These copepods were found to be closely associated with 183 octocoral species, representing 72 genera and 28 families. The analysis revealed a total of 393 distinct interspecific associations between copepods, classified under the orders Cyclopoida, Harpacticoida, and Siphonostomatoida, and diverse octocorals. Approximately 60% of these associations were reported only once in the literature, which poses challenges to assessing the level of host specificity among the majority of copepod species linked with octocorals. Notably, over 91% of the recorded copepod species were found at depths not exceeding 30 m, with only four copepod species reported at greater depths surpassing 500 m. The presence of these symbiotic copepods was documented across 215 sampling sites situated within 8 of the 12 defined marine ecoregions, with particular attention to the Western Indo-Pacific, Central Indo-Pacific, and Temperate Northern regions. Despite the comprehensive examination of available data, this study highlights substantial gaps in our comprehension of copepod crustacean diversity and distribution in association with octocorals. Moreover, crucial information concerning symbiotic copepods is conspicuously absent for approximately 94% of potential octocoral host species. These disparities emphasize the imperative need for further scientific inquiry to unveil the intricacies of symbiotic relationships and to contribute to a more holistic understanding of copepod–octocoral associations.
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Piontkovski, Sergey A., Asila Al-Maawali, Ward Al-Muna Al-Manthri, Khalid Al-Hashmi, and Elena A. Popova. "Zooplankton of Oman Coastal Waters." Journal of Agricultural and Marine Sciences [JAMS] 19 (January 1, 2014): 37. http://dx.doi.org/10.24200/jams.vol19iss0pp37-50.
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Monthly sampling during daytime was carried out in 2007-2011 at Bandar Al-Khyran (23.51oN, 58.72oE) which is the largest semi-enclosed bay on the southern end of the Sea of Oman with about 4 km2 in surface area and an average depth of 10 m. Zooplankton were represented by Copepoda (79%), Cladocera (9%), Oikopleuriddae (7%), Chaetognatha (3%), and Decapoda (~2%) comprising the major part of the total zooplankton abundance. Among copepods, 27 species constituted ~75% of total copepod abundance. Changes of copepod abundance have not had a pronounced seasonal pattern. Instead, a multiple peak structure in monthly fluctuations was observed, on the level of genera as well as the abundance of species. Amplitudes and timing of the copepod peak abundance were markedly different during the studied years.
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Tang, Kam, Claudia Dziallas, Kristine Hutalle-Schmelzer, and Hans-Peter Grossart. "Effects of food on bacterial community composition associated with the copepod Acartia tonsa Dana." Biology Letters 5, no. 4 (2009): 549–53. http://dx.doi.org/10.1098/rsbl.2009.0076.
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The estuarine copepod Acartia tonsa naturally carried diverse strains of bacteria on its body. The bacterial community composition (BCC) remained very conservative even when the copepod was fed different axenic algal species, indicating that the food per se did not much affect BCC associated with the copepod. In xenic algal treatments, however, copepod-associated BCC differed with each alga fed, even though the same bacterial source was used to inoculate the algae. In addition, starved copepods taken at the same location but at different times significantly differed in their BCC. Algal species composition and copepod life history therefore serve to regulate BCC associated with copepods, and spatial and temporal variations in algal species composition and copepod origin would alter bacteria–copepod interactions.
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Korzhavina, Oksana A., Mikhail A. Nikitin, Bert W. Hoeksema, Maickel Armenteros, James D. Reimer, and Viatcheslav N. Ivanenko. "Tracing Geographic and Molecular Footprints of Copepod Crustaceans Causing Multifocal Purple Spots Syndrome in the Caribbean Sea Fan Gorgonia ventalina." Diversity 16, no. 5 (2024): 280. http://dx.doi.org/10.3390/d16050280.
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The recent rise in ocean temperatures, accompanied by other environmental changes, has notably increased the occurrence and spread of diseases in Octocorallia, many species of which are integral to shallow tropical and subtropical coral reef ecosystems. This study focuses on the understanding of these diseases, which has been largely limited to symptomatic descriptions, with clear etiological factors identified in only a fraction of cases. A key example is the multifocal purple spots syndrome (MFPS) affecting the common Caribbean octocoral sea fan Gorgonia ventalina, linked to the gall-forming copepods of the genus Sphaerippe, a member of the widespread family, Lamippidae. The specialized nature of these copepods as endoparasites in octocorals suggests the potential for the discovery of similar diseases across this host spectrum. Our investigation employed four molecular markers to study disease hotspots in Saint Eustatius, Curaçao, northwest and southwest Cuba, and Bonaire. This led to the discovery of a group of copepod species in these varied Caribbean locations. Importantly, these species are morphologically indistinguishable through traditional methods, challenging established taxonomic approaches. The observed diversity of symbionts, despite the host species’ genetic uniformity, is likely due to variations in larval dispersal mechanisms. Our phylogenetic analyses confirmed that the Lamippidae copepods belong to the order, Poecilostomatoida (Copepoda), and revealed their sister group relationship with the Anchimolgidae, Rhynchomolgidae, and Xarifiidae clades, known for their symbiotic relationships with scleractinian corals. These results add to our understanding of the evolutionary and ecological interactions of copepods and their hosts, and the diseases that they cause, and are important data in a changing climate.
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Ashaari, Aisyah, Amilya Syazlyn Abdul Jalal, Nabilah Abdul Hadi, Siti Rohana Yatim, and Nadiah Wan Rasdi. "Effects of herbs enriched copepod and its potential use in whiteleg shrimp (Litopenaeus vannamei) post-larvae culture." IOP Conference Series: Earth and Environmental Science 1432, no. 1 (2024): 012008. https://doi.org/10.1088/1755-1315/1432/1/012008.
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Abstract Copepods are important source of food for prawn larvae in hatcheries because of their rich nutritional content including proteins, lipids and fatty acids. However, copepod needed nutritional enhancement due to their insufficient nutrition to meet the requirement of fish and shrimp species. This study was conducted to observe the potential of herb plants in boosting the nutritional value of copepods as well as to determine the nutritional composition of Litopenaeus vannamei fed with the enriched copepod. Four treatments with three replicates used to analyze the effectiveness of enriched copepod to L. vannamei post-larvae. The diets consist of ginger, (Zingiber officinale Roscoe), mint (Mentha piperita), spadeleaf (Centella asiatica) and unfed treatments that serve as a control. Copepods supplemented twice daily at concentration of 500 mg/L. Whiteleg shrimp post-larvae growth and nutritional composition performed to observe the efficacy of each selected diet. Protein, lipid, specific population growth rate and hatching rate of the enriched copepod was found to be highest in the treatment of C. asiatica and it also has been observed that survival rate and specific growth rate of L. vannamei fed with copepod that enriched with C. asiatica were the highest with value of 85.00±5.00% and 8.14±0.39% respectively. This study contributes to the development of cost-effective and sustainable alternatives, emphasizing the potential of herb-enriched copepods, particularly with C. asiatica, to address economic challenges and promote environmental sustainability in shrimp farming practices.
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Labuce, Astra, Solvita Strake, and Inta Dimante-Deimantovica. "Eurytemora affinis (Poppe, 1880) (Copepoda, Calanoida) in the Gulf of Riga, Baltic Sea — elemental composition and diurnal vertical migration." Crustaceana 93, no. 3-5 (2020): 447–66. http://dx.doi.org/10.1163/15685403-00003977.
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Abstract The present paper reports the results of two surveys conducted in the Gulf of Riga (Baltic Sea) during 1997. Elemental composition (carbon and nitrogen) and diurnal vertical migration (DVM) throughout development of the calanoid copepod Eurytemora affinis (Poppe, 1880) were studied. This is a species with a high genetic and morphological heterogeneity, inhabiting a seasonally stratified, herring (Clupea harengus Linnaeus, 1758) rich ecosystem. The DVM of copepods is a widespread advantageous behaviour, although with several trade-offs. At the expense of time spent in the food-richer surface layer, copepods avoid visual predators (planktivorous fish) by descending to greater depths, thereby decreasing their mortality. Being a part of the food web, copepods themselves serve as a source of nutrients with specific elemental contents. In the present study, we observed differences both in DVM and elemental content between the developmental stages of the studied species. The majority (57-89%) of nauplii and 1st to 3rd copepodids were found near the thermocline during daytime, whereas at night they were detected above the thermocline. The 5th stage copepodids and adults displayed evident nocturnal ascent, when most (>90%) individuals moved above 15 m depth. During daytime, they tended to disperse throughout the water column. Carbon (C%) and nitrogen (N%) in dry weight of E. affinis increased with ontogenetic development, reaching the highest values in 4th to 5th copepodids and adults. Adult males showed higher values of C% and N%, as well as an increased C : N molar ratio, compared to adult non-ovigerous females. The amount of time spent at the food-richer surface layer appeared to be related to N% in E. affinis.
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De Troch, M., M. Roelofs, B. Riedel, and M. Grego. "Structural and functional responses of harpacticoid copepods to anoxia in the Northern Adriatic: an experimental approach." Biogeosciences 10, no. 6 (2013): 4259–72. http://dx.doi.org/10.5194/bg-10-4259-2013.
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Abstract. Combined in situ and laboratory studies were conducted to document the effects of anoxia on the structure and functioning of meiobenthic communities, with special focus on harpacticoid copepods. In a first step, anoxia was created artificially by means of an underwater chamber at 24 m depth in the Northern Adriatic, Gulf of Trieste (Mediterranean). Nematodes were found as the most abundant taxon, followed by harpacticoid copepods. While nematode densities were not affected by treatment (anoxia/normoxia) or sediment depth, these factors had a significant impact on copepod abundances. Harpacticoid copepod family diversity, in contrast, was not affected by anoxic conditions, only by depth. Ectinosomatidae and Cletodidae were most abundant in both normoxic and anoxic samples. The functional response of harpacticoid copepods to anoxia was studied in a laboratory tracer experiment by adding 13C pre-labelled diatoms to sediment cores in order to test (1) if there is a difference in food uptake by copepods under normoxic and anoxic conditions and (2) whether initial (normoxia) feeding of harpacticoid copepods on diatoms results in a better survival of copepods in subsequent anoxic conditions. Independent of the addition of diatoms, there was a higher survival rate in normoxia than anoxia. The supply of additional food did not result in a higher survival rate of copepods in anoxia, which might be explained by the presence of a nutritionally better food source and/or a lack of starvation before adding the diatoms. However, there was a reduced grazing pressure by copepods on diatoms in anoxic conditions. This resulted in a modified fatty acid composition of the sediment. We concluded that anoxia not only impacts the survival of consumers (direct effect) but also of primary producers (indirect effect), with important implications for the recovery phase.
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De Troch, M., M. Roelofs, B. Riedel, and M. Grego. "Structural and functional responses of harpacticoid copepods to anoxia in the Northern Adriatic: an experimental approach." Biogeosciences Discussions 10, no. 2 (2013): 2479–514. http://dx.doi.org/10.5194/bgd-10-2479-2013.
Full textAbstract:
Abstract. Combined in situ and laboratory studies were conducted to document the effects of anoxia on the structure and functioning of meiobenthic communities, with special focus on harpacticoid copepods. In a first step, anoxia was created artificially by means of an underwater chamber at 24 m depth in the Northern Adriatic, Gulf of Trieste (Mediterranean). Nematodes were found as most abundant taxon, followed by harpacticoid copepods. While nematode densities were not affected by treatment (anoxia/normoxia) or sediment depth, these factors had a significant impact on copepod abundances. Harpacticoid copepod family diversity, in contrast, was not affected by anoxic conditions, only by depth. Ectinosomatidae and Cletodidae were most abundant in both normoxic and anoxic samples. The functional response of harpacticoid copepods to anoxia was studied in a laboratory tracer experiment by adding 13C pre-labelled diatoms to sediment cores in order to test (1) if there is a difference in food uptake by copepods under normoxic and anoxic conditions and (2) whether initial (normoxia) feeding of harpacticoid copepods on diatoms results in a better survival of copepods in subsequent anoxic conditions. Independent of the addition of diatoms, there was a higher survival rate in normoxia than anoxia. The supply of additional food did not result in a higher survival rate of copepods in anoxia, which might be explained by the presence of a nutritionally better food source and/or a lack of starvation before adding the diatoms. However, there was a reduced grazing pressure by copepods on diatoms in anoxic conditions. This resulted in a modified fatty acid composition of the sediment. We concluded that anoxia not only impacts the survival of consumers (direct effect) but also of primary producers (indirect effect), with important implications for the recovery phase.
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Poulin, R., M. A. Curtis, and M. E. Rau. "Effects of Eubothrium salvelini (Cestoda) on the behaviour of Cyclops vernalis (Copepoda) and its susceptibility to fish predators." Parasitology 105, no. 2 (1992): 265–71. http://dx.doi.org/10.1017/s0031182000074199.
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SUMMARYTo facilitate the completion of their life-cycle, many helminth parasites have evolved the ability to manipulate the behaviour of their intermediate host in order to make it more likely to be eaten by the parasite's definitive host. Here, we determined whether the cestode Eubothrium salvelini modifies the behaviour of its intermediate host, the copepod Cyclops vernalis, and makes it more susceptible to predation by brook trout, Salvelinus fontinalis, the parasite's final host. Following the experimental infection of copepods, the spontaneous activity of infected and control subjects was quantified weekly. In addition, we regularly quantified predation by individual brook trout fry on known numbers of infected and control copepods. At approximately the time when the cestode larvae became infective to fish (2–3 weeks following infection), the infected copepods started to swim more actively than uninfected controls. Also at that time, infected individuals became more likely to be captured by fish than uninfected ones. Copepod size and intensity of infection had no significant effect on their behaviour or their risk of being eaten by fish. Thus cestode- induced changes in copepod swimming activity can lead to infected copepods becoming highly vulnerable to fish predators, and may have resulted from selection on the parasite to increase its transmission success
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Vargas, C. A., R. A. Martínez, R. Escribano, and N. A. Lagos. "Seasonal relative influence of food quantity, quality, and feeding behaviour on zooplankton growth regulation in coastal food webs." Journal of the Marine Biological Association of the United Kingdom 90, no. 6 (2009): 1189–201. http://dx.doi.org/10.1017/s0025315409990804.
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In aquatic food webs zooplankton constitutes an important link between primary producers and higher trophic levels. Copepods often dominate the zooplankton in coastal oceans and are the prey of the majority of planktivorous fish. Feeding behaviour, as well as the food quantity and quality are recognized factors that affect copepod growth, and therefore, the energy transfer efficiency throughout food webs. The natural occurrence and magnitude of these growth factors and their combined effects on marine copepods, as keystone grazers in the pelagic marine realm, are poorly understood. Here, we assessed how these different factors vary throughout the year, and then examine their relative influence upon copepods maximal growth rates. A multiple regression model, including all variables previously selected, and the inclusion of the sea temperature allowed us to estimate the pure influence of the studied factors, and the environmental effect on copepod growth rates. The results imply that ingestion of diatoms may induce a positive effect on specific growth rates of copepods, and the quality of this food item (high PUFA and HUFA availability) might explain such effect. Therefore, seasonal variability in diatom abundance, possibly driven by changes in the oceanographic regime, should be considered a critical factor controlling copepod growth in productive coastal ecosystems.
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Roziaty, Efri, Afrika Arianto, and Vina Listiawati. "A Diversity of Copepods in Gajah Mungkur in Wonogiri Regency, Central Java, Indonesia." Bioeksperimen: Jurnal Penelitian Biologi 9, no. 2 (2023): 160–66. http://dx.doi.org/10.23917/bioeksperimen.v9i2.23143.
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GajahMungkur Reservoir is a freshwater ecosystem thatis located6kmsouthofWonogiri Regency,CentralJavaProvince. Zooplankton is the primary consumer in the food chain of aquatic ecosystems. One of the common zooplankton found in freshwater ecosystem is copepod. Copepod is sensitive organism and play an important role as bioindicatator of water quality. The aimed of this study was to investigate the copepods diversity in Gajah Mungkur Reservoir. The method applied to this study is exploration and application of purposive sampling techniques in sampling. Copepods were collected from three different station, namely Station 1 (fishing area), Station 2 (tourism area), and Station 3 (fish cage area or keramba). The abiotic parameters were found to be varied on each station. Results showed that Gajah Mungkur Reservoir has moderately diverse copepods species with the average of diversity index 1.21. There were 7 species of copepods found in Gajah Mungkur Reservoir which mostly dominated by Mesocyclops sp., especially in Station 1 (fishing area). Meanwhile Microcyclops sp. was only found in Station 3 (fish cage area or keramba), suggesting that this species has a potential as bioindicator in Gajah Mungkur Reservoir. This study suggest that changes in physicochemical parameters might influence the diversity and abundance of copepod in Gajah Mungkur Reservoir.
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Feng, Jiantong, Maurizio Mazzei, Simona Di Gregorio, et al. "Marine Copepods as a Microbiome Hotspot: Revealing Their Interactions and Biotechnological Applications." Water 15, no. 24 (2023): 4203. http://dx.doi.org/10.3390/w15244203.
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Copepods are the most abundant organisms in marine zooplankton and the primary components of the food chain. They are hotspots for highly adaptable microorganisms, which are pivotal in biogeochemical cycles. The microbiome, encompassing microorganisms within and surrounding marine planktonic organisms, holds considerable potential for biotechnological advancements. Despite marine microbiome research interests expanding, our understanding of the ecological interactions between microbiome and copepods remains limited. This review intends to give an overview of the recent studies regarding the microbiome associated with marine copepods, with particular focus on the diversity of bacteria and fungi. The significance of copepod-associated microbiomes in different contexts, such as aquaculture and biodegradation processes, was evaluated. The ability of the microbiome to mitigate harmful bacterial growth in cultured organisms was also explored. The microbiome associated with copepods has demonstrated efficacy in reducing the proliferation of detrimental bacteria in aquaculture, paving the way for the commercial utilization of natural zooplankton in fish rearing. Additionally, copepod-associated microbiomes may play a role in addressing marine environmental challenges, such as the bioremediation of polluted marine matrices. Overall, this review represents a basis for investigating intricate copepod-associated microbiomes and their diverse applications, enhancing our comprehension of the ecological and evolutionary significance of marine microbiomes.