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Sample records for caligus rogercresseyi copepoda

  1. TLR and IMD signaling pathways from Caligus rogercresseyi (Crustacea: Copepoda): in silico gene expression and SNPs discovery.

    PubMed

    Valenzuela-Muñoz, V; Gallardo-Escárate, C

    2014-02-01

    The Toll and IMD signaling pathways represent one of the first lines of innate immune defense in invertebrates like Drosophila. However, for crustaceans like Caligus rogercresseyi, there is very little genomic information and, consequently, understanding of immune mechanisms. Massive sequencing data obtained for three developmental stages of C. rogercresseyi were used to evaluate in silico the expression patterns and presence of SNPs variants in genes involved in the Toll and IMD pathways. Through RNA-seq analysis, which used 20 contigs corresponding to relevant genes of the Toll and IMD pathways, an overexpression of genes linked to the Toll pathway, such as toll3 and Dorsal, were observed in the copepod stage. For the chalimus and adult stages, overexpression of genes in both pathways, such as Akirin and Tollip and IAP and Toll9, respectively, were observed. On the other hand, PCA statistical analysis inferred that in the chalimus and adult stages, the immune response mechanism was more developed, as evidenced by a relation between these two stages and the genes of both pathways. Moreover, 136 SNPs were identified for 20 contigs in genes of the Toll and IMD pathways. This study provides transcriptomic information about the immune response mechanisms of Caligus, thus providing a foundation for the development of new control strategies through blocking the innate immune response. PMID:24389530

  2. Increasing transcriptome response of serpins during the ontogenetic stages in the salmon louse Caligus rogercresseyi (Copepoda: Caligidae).

    PubMed

    Maldonado-Aguayo, W; Gallardo-Escárate, C

    2014-06-01

    Serine protease inhibitors, or serpins, target serine proteases, and are important regulators of intra- and extracellular proteolysis. For parasite survival, parasite-derived protease inhibitors have been suggested to play essential roles in evading the host's immune system and protecting against exogenous host proteases. The aim of this work was to identify serpins via high throughput transcriptome sequencing and elucidate their potential functions during the lifecycle of the salmon louse Caligus rogercresseyi. Eleven putative, partial serpin sequences in the C. rogercresseyi transcriptome were identified and denoted as Cr-serpins 1 to 11. Comparative analysis of the deduced serpin-like amino acid sequences revealed a highly conserved reactive center loop region. Interestingly, P1 residues suggest putative functions involved with the trypsin/subtilisin, elastase, or subtilisin inhibitors, which evidenced increasing gene expression profiles from the copepodid to adult stage in C. rogercresseyi. Concerning this, Cr-serpin 10 was mainly expressed in the copepodid stage, while Cr-serpins 3, 4, 5, and 11 were mostly expressed in chalimus and adult stages. These results suggest that serpins could be involved in evading the immune response of the host fish. The identification of these serpins furthers the understanding of the immune system in this important ectoparasite species. PMID:24798872

  3. Novel gene isolated from Caligus rogercresseyi: a promising target for vaccine development against sea lice.

    PubMed

    Carpio, Yamila; Basabe, Liliana; Acosta, Jannel; Rodríguez, Alina; Mendoza, Adriana; Lisperger, Angélica; Zamorano, Eugenio; González, Margarita; Rivas, Mario; Contreras, Sergio; Haussmann, Denise; Figueroa, Jaime; Osorio, Verónica N; Asencio, Gladys; Mancilla, Jorge; Ritchie, Gordon; Borroto, Carlos; Estrada, Mario Pablo

    2011-03-24

    Sea lice (Copepoda, Caligidae) are the most widely distributed marine pathogens in the salmon industry in the last 30 years. Caligus rogercresseyi is the most important species affecting Chile's salmon industry. Vaccines against caligid copepods have the potential to be a cost-effective means of controlling the infestation and avoid many of the disadvantages of medicine treatments. However, research in the development of such vaccines has begun only recently and approaches used thus far have met with little or no success. In the present study, we characterized a novel gene (denoted as my32) from C. rogercresseyi which has the highest identity with the Lepeophtheirus salmonis gene akirin-2. To assess the function of the gene an RNA interference experiment was developed and a reduction in the number of ectoparasites on fish in the my32-dsRNA treated group was observed. The recombinant my32 protein was used in a vaccination-challenge trial to evaluate its ability to protect against sea lice infestations. A significant reduction in the number of parasites per fish was observed at 24 days post-challenge. These results, together with the delay observed in the development of parasites from the vaccinated group suggest that the major effect of immunization was on the second parasite generation. The results of these experiments suggest that the my32 protein may be a promising target for vaccine development to control sea lice infestations in fish. PMID:21320542

  4. Prohibitin-2 gene reveals sex-related differences in the salmon louse Caligus rogercresseyi.

    PubMed

    Farlora, Rodolfo; Nuñez-Acuña, Gustavo; Gallardo-Escárate, Cristian

    2015-06-10

    Prohibitins are evolutionarily conserved proteins present in multiple cellular compartments, and are involved in diverse cellular processes, including steroid hormone transcription and gametogenesis. In the present study, we report for the first time the characterization of the prohibitin-2 (Phb2) gene in the sea lice Caligus rogercresseyi. The CrPhb2 cDNA showed a total length of 1406 bp, which contained a predicted open reading frame (ORF) of 894 base pairs (bp) encoding for 298 amino acids. Multiple sequence alignments of prohibitin proteins from other arthropods revealed a high degree of amino acid sequence conservation. In silico Illumina read counts and RT-qPCR analyses showed a sex-dependent differential expression, with mRNA levels exhibiting a 1.7-fold (RT-qPCR) increase in adult females compared with adult males. A total of nine single nucleotide polymorphisms (SNPs) were identified, three were located in the 5' UTR of the Phb2 messenger and six in the ORF, but no mutations associated with sex were found. These results contribute to expand the present knowledge of the reproduction-related genes in C. rogercresseyi, and may be useful in future experiments aimed at controlling the impacts of sea lice in fish farming. PMID:25813873

  5. Transcriptome mining: Multigene panel to test delousing drug response in the sea louse Caligus rogercresseyi.

    PubMed

    Valenzuela-Muñoz, V; Gallardo-Escárate, C

    2016-02-01

    Controlling infestations of copepodid ectoparasites in the salmon industry is increasingly problematic given higher instances of drug resistance or loss of sensitivity. Despite the importance of this issue, the molecular mechanisms and genes implicated in resistance/susceptibility are only scarcely understood. The objective of the present study was to identify and evaluate the expression levels of candidate genes associated with delousing drug response in the sea louse Caligus rogercresseyi. From RNA-seq data obtained for adult male and female sea lice, 62.48 M reads were assembled in 70,349 high-quality contigs. BLASTX analysis against UniprotKB/Swiss-Prot and the ESTs available for crustaceans in the NCBI database identified 870 transcripts previously related to genes associated with delousing drug response. Furthermore, 14 candidate genes were validated through RT-qPCR and were evaluated with deltamethrin and azamethiphos bioassays. The results evidenced an overregulation of genes involved in ion transport in salmon lice treated with deltamethrin, while those treated with azamethiphos evidenced an overregulation of genes such as cytochrome P450, Carboxylesterase, and acetylcholine receptors. The present study provides a multigene panel to test delousing drug response to pyrethroids and organophosphates in a highly prevalent pathogen of the Chilean salmon industry. PMID:26723558

  6. MicroRNA biogenesis pathway from the salmon louse (Caligus rogercresseyi): emerging role in delousing drug response.

    PubMed

    Valenzuela-Miranda, Diego; Nuñez-Acuña, Gustavo; Valenzuela-Muñoz, Valentina; Asgari, Sassan; Gallardo-Escárate, Cristian

    2015-01-25

    Despite the increasing evidence of the importance of microRNAs (miRNAs) in the regulation of multiple biological processes, the molecular bases supporting this regulation are still barely understood in crustaceans. Therefore, the molecular characterization and transcriptome modulation of the miRNA biogenesis pathway were evaluated in the salmon louse Caligus rogercresseyi, an ectoparasite that constitutes one of the biggest concerns for salmonid aquaculture industry. Hence, RNA-Seq analysis was conducted from six different developmental stages, and also after bioassays with delousing drugs Deltamethrin and Azamethiphos using adult individuals. In silico analysis evidenced 24 putative genes involved in the miRNA pathway such as biogenesis, transport, maturation and miRNA-target interaction. Moreover, 243 putative single nucleotide polymorphisms (SNPs) were identified, 15 of which showed non-synonym mutations. RNA-Seq analysis revealed that CCR4-Not complex subunit 3 (CNOT3) was upregulated at earlier developmental stages (nauplius I-II and copepodid), and also after the exposure to Azamethiphos, but not to Deltamethrin. In contrast, the subunit 7 (CNOT7) showed an inverse expression pattern. Different Argonaute transcripts were associated to chalimus and adult stages, revealing specific expression patterns in response to antiparasitic drugs. Our results suggest novel insights into the regulatory network of the post-transcriptional gene regulation in C. rogercresseyi mediated by miRNAs, evidencing a putative role during the ontogeny and drug response. PMID:25447902

  7. Stress response of Salmo salar (Linnaeus 1758) when heavily infested by Caligus rogercresseyi (Boxshall & Bravo 2000) copepodids.

    PubMed

    González, Margarita P; Vargas-Chacoff, Luis; Marín, Sandra L

    2016-02-01

    The year-round presence of ovigerous females of the parasite Caligus rogercresseyi in the fish farms of southern Chile results in a continuous source of the copepodid (infestive) stage of this louse. The short generation time in spring-summer could lead to high abundances of this copepodid, potentially leading to high infestation levels for fish. Knowing how heavy lice infestations affect Salmo salar can help determine how to time antiparasitic treatments so as to both minimize the treatment impact and reduce lice infestation levels for fish. This study aimed to describe the effects of high infestations of the copepodid stage of C. rogercresseyi on the physiology of S. salar. Two groups of S. salar were used: an infested group (75 copepodids per fish) and a control group (not infested). Sixty-five days after the first infestation, the infested fish group was re-infested at an infestation pressure of 200 copepodids per fish. Sampling was done prior to and following the second infestation, at 56 and 67 days (the latter 2 days following the second infestation). Several physiological variables were measured: cortisol (primary stress response) and glucose, proteins, amino acids, triglycerides, lactate, osmolality levels, and number and diameter of skin mucous cells (secondary stress responses). The plasma cortisol, glucose, and triglyceride levels were altered in the heavily infested fish, as was the diameter of skin mucous cells. These results suggest that heavy infestations of C. rogercresseyi lead to an acute stress response, metabolic reorganization, and increased mucus production in S. salar under heavy infestation conditions. PMID:26394864

  8. Cathepsin Gene Family Reveals Transcriptome Patterns Related to the Infective Stages of the Salmon Louse Caligus rogercresseyi

    PubMed Central

    Maldonado-Aguayo, Waleska; Chávez-Mardones, Jacqueline; Gonçalves, Ana Teresa; Gallardo-Escárate, Cristian

    2015-01-01

    Cathepsins are proteases involved in the ability of parasites to overcome and/or modulate host defenses so as to complete their own lifecycle. However, the mechanisms underlying this ability of cathepsins are still poorly understood. One excellent model for identifying and exploring the molecular functions of cathepsins is the marine ectoparasitic copepod Caligus rogercresseyi that currently affects the Chilean salmon industry. Using high-throughput transcriptome sequencing, 56 cathepsin-like sequences were found distributed in five cysteine protease groups (B, F, L, Z, and S) as well as in an aspartic protease group (D). Ontogenic transcriptome analysis evidenced that L cathepsins were the most abundant during the lifecycle, while cathepsins B and K were mostly expressed in the larval stages and adult females, thus suggesting participation in the molting processes and embryonic development, respectively. Interestingly, a variety of cathepsins from groups Z, L, D, B, K, and S were upregulated in the infective stage of copepodid, corroborating the complexity of the processes involved in the parasitic success of this copepod. Putative functional roles of cathepsins were conjectured based on the differential expressions found and on roles previously described in other phylogenetically related species. Moreover, 140 single nucleotide polymorphisms (SNP) were identified in transcripts annotated for cysteine and aspartic proteases located into untranslated regions, or the coding region. This study reports for the first time the presence of cathepsin-like genes and differential expressions throughout a copepod lifecycle. The identification of cathepsins together with functional validations represents a valuable strategy for pinpointing target molecules that could be used in the development of new delousing drugs or vaccines against C. rogercresseyi. PMID:25923525

  9. Aquaporin family genes exhibit developmentally-regulated and host-dependent transcription patterns in the sea louse Caligus rogercresseyi.

    PubMed

    Farlora, Rodolfo; Valenzuela-Muñoz, Valentina; Chávez-Mardones, Jacqueline; Gallardo-Escárate, Cristian

    2016-07-01

    Aquaporins are small integral membrane proteins that function as pore channels for the transport of water and other small solutes across the cell membrane. Considering the important roles of these proteins in several biological processes, including host-parasite interactions, there has been increased research on aquaporin proteins recently. The present study expands on the knowledge of aquaporin family genes in parasitic copepods, examining diversity and expression during the ontogeny of the sea louse Caligus rogercresseyi. Furthermore, aquaporin expression was evaluated during the early infestation of Atlantic (Salmo salar) and Coho salmon (Oncorhynchus kisutch). Deep transcriptome sequencing data revealed eight full length and two partial open reading frames belonging to the aquaporin protein family. Clustering analyses with identified Caligidae sequences revealed three major clades of aquaglyceroporins (Cr-Glp), classical aquaporin channels (Cr-Bib and Cr-PripL), and unorthodox aquaporins (Cr-Aqp12-like). In silico analysis revealed differential expression of aquaporin genes between developmental stages and between sexes. Male-biased expression of Cr-Glp1_v1 and female-biased expression of Cr-Bib were further confirmed in adults by RT-qPCR. Additionally, gene expressions were measured for seven aquaporins during the early infestation stage. The majority of aquaporin genes showed significant differential transcription expressions between sea lice parasitizing different hosts, with Atlantic salmon sea lice exhibiting overall reduced expression as compared to Coho salmon. The observed differences in the regulation of aquaporin genes may reveal osmoregulatory adaptations associated with nutrient ingestion and metabolite waste export, exposing complex host-parasite relationships in C. rogercresseyi. PMID:27016299

  10. RNA-Seq Analysis Using De Novo Transcriptome Assembly as a Reference for the Salmon Louse Caligus rogercresseyi

    PubMed Central

    Gallardo-Escárate, Cristian; Valenzuela-Muñoz, Valentina; Nuñez-Acuña, Gustavo

    2014-01-01

    Despite the economic and environmental impacts that sea lice infestations have on salmon farming worldwide, genomic data generated by high-throughput transcriptome sequencing for different developmental stages, sexes, and strains of sea lice is still limited or unknown. In this study, RNA-seq analysis was performed using de novo transcriptome assembly as a reference for evidenced transcriptional changes from six developmental stages of the salmon louse Caligus rogercresseyi. EST-datasets were generated from the nauplius I, nauplius II, copepodid and chalimus stages and from female and male adults using MiSeq Illumina sequencing. A total of 151,788,682 transcripts were yielded, which were assembled into 83,444 high quality contigs and subsequently annotated into roughly 24,000 genes based on known proteins. To identify differential transcription patterns among salmon louse stages, cluster analyses were performed using normalized gene expression values. Herein, four clusters were differentially expressed between nauplius I–II and copepodid stages (604 transcripts), five clusters between copepodid and chalimus stages (2,426 transcripts), and six clusters between female and male adults (2,478 transcripts). Gene ontology analysis revealed that the nauplius I–II, copepodid and chalimus stages are mainly annotated to aminoacid transfer/repair/breakdown, metabolism, molting cycle, and nervous system development. Additionally, genes showing differential transcription in female and male adults were highly related to cytoskeletal and contractile elements, reproduction, cell development, morphogenesis, and transcription-translation processes. The data presented in this study provides the most comprehensive transcriptome resource available for C. rogercresseyi, which should be used for future genomic studies linked to host-parasite interactions. PMID:24691066

  11. Cathepsin Gene Family Reveals Transcriptome Patterns Related to the Infective Stages of the Salmon Louse Caligus rogercresseyi.

    PubMed

    Maldonado-Aguayo, Waleska; Chávez-Mardones, Jacqueline; Gonçalves, Ana Teresa; Gallardo-Escárate, Cristian

    2015-01-01

    Cathepsins are proteases involved in the ability of parasites to overcome and/or modulate host defenses so as to complete their own lifecycle. However, the mechanisms underlying this ability of cathepsins are still poorly understood. One excellent model for identifying and exploring the molecular functions of cathepsins is the marine ectoparasitic copepod Caligus rogercresseyi that currently affects the Chilean salmon industry. Using high-throughput transcriptome sequencing, 56 cathepsin-like sequences were found distributed in five cysteine protease groups (B, F, L, Z, and S) as well as in an aspartic protease group (D). Ontogenic transcriptome analysis evidenced that L cathepsins were the most abundant during the lifecycle, while cathepsins B and K were mostly expressed in the larval stages and adult females, thus suggesting participation in the molting processes and embryonic development, respectively. Interestingly, a variety of cathepsins from groups Z, L, D, B, K, and S were upregulated in the infective stage of copepodid, corroborating the complexity of the processes involved in the parasitic success of this copepod. Putative functional roles of cathepsins were conjectured based on the differential expressions found and on roles previously described in other phylogenetically related species. Moreover, 140 single nucleotide polymorphisms (SNP) were identified in transcripts annotated for cysteine and aspartic proteases located into untranslated regions, or the coding region. This study reports for the first time the presence of cathepsin-like genes and differential expressions throughout a copepod lifecycle. The identification of cathepsins together with functional validations represents a valuable strategy for pinpointing target molecules that could be used in the development of new delousing drugs or vaccines against C. rogercresseyi. PMID:25923525

  12. Transcriptome immunomodulation of in-feed additives in Atlantic salmon Salmo salar infested with sea lice Caligus rogercresseyi.

    PubMed

    Núñez-Acuña, Gustavo; Gonçalves, Ana Teresa; Valenzuela-Muñoz, Valentina; Pino-Marambio, Jorge; Wadsworth, Simon; Gallardo-Escárate, Cristian

    2015-11-01

    One of the most significant threats to the Chilean salmon aquaculture industry is the ectoparasitic sea louse Caligus rogercresseyi. To cope with sea lice infestations, functional diets have become an important component in strengthening the host immune response. The aim of this study was to evaluate molecular mechanisms activated through immunostimulation by in-feed plant-derived additives in Atlantic salmon infected with sea lice. Herein, a transcriptome-wide sequencing analysis was performed from skin and head kidney tissues, evidencing that the immune response genes were the most variable after the challenge, especially in the head kidney, while other genes involved in metabolism were highly expressed individuals fed with the immunostimulants. Interestingly, defensive enzymes such as Cytochrome p450 and serpins were down-regulated in infested individuals, especially in skin tissue. Additionally, MHC-I and MHC-II genes were differentially expressed after the incorporation of the in-feed additives, giving some cues about the protection mechanisms of plant-derived compound as immunostimulants for infested salmons. This is the first published study that evaluates the transcriptomic response of sea lice-infested Atlantic salmon fed with in-feed additives. PMID:26363235

  13. Disease Resistance in Atlantic Salmon (Salmo salar): Coinfection of the Intracellular Bacterial Pathogen Piscirickettsia salmonis and the Sea Louse Caligus rogercresseyi

    PubMed Central

    Lhorente, Jean Paul; Gallardo, José A.; Villanueva, Beatriz; Carabaño, María J.; Neira, Roberto

    2014-01-01

    Background Naturally occurring coinfections of pathogens have been reported in salmonids, but their consequences on disease resistance are unclear. We hypothesized that 1) coinfection of Caligus rogercresseyi reduces the resistance of Atlantic salmon to Piscirickettsia salmonis; and 2) coinfection resistance is a heritable trait that does not correlate with resistance to a single infection. Methodology In total, 1,634 pedigreed Atlantic salmon were exposed to a single infection (SI) of P. salmonis (primary pathogen) or coinfection with C. rogercresseyi (secondary pathogen). Low and high level of coinfection were evaluated (LC = 44 copepodites per fish; HC = 88 copepodites per fish). Survival and quantitative genetic analyses were performed to determine the resistance to the single infection and coinfections. Main Findings C. rogercresseyi significantly increased the mortality in fish infected with P. salmonis (SI mortality = 251/545; LC mortality = 544/544 and HC mortality = 545/545). Heritability estimates for resistance to P. salmonis were similar and of medium magnitude in all treatments (h2SI = 0.23±0.07; h2LC = 0.17±0.08; h2HC = 0.24±0.07). A large and significant genetic correlation with regard to resistance was observed between coinfection treatments (rg LC-HC = 0.99±0.01) but not between the single and coinfection treatments (rg SI-LC = −0.14±0.33; rg SI-HC = 0.32±0.34). Conclusions/Significance C. rogercresseyi, as a secondary pathogen, reduces the resistance of Atlantic salmon to the pathogen P. salmonis. Resistance to coinfection of Piscirickettsia salmonis and Caligus rogercresseyi in Atlantic salmon is a heritable trait. The absence of a genetic correlation between resistance to a single infection and resistance to coinfection indicates that different genes control these processes. Coinfection of different pathogens and resistance to coinfection needs to be considered in future research on salmon

  14. Evidence for the Induction of Key Components of the NOTCH Signaling Pathway via Deltamethrin and Azamethiphos Treatment in the Sea Louse Caligus rogercresseyi

    PubMed Central

    Boltaña, Sebastian; Chávez-Mardones, Jaqueline; Valenzuela-Muñoz, Valentina; Gallardo-Escárate, Cristian

    2016-01-01

    The extensive use of organophosphates and pyrethroids in the aquaculture industry has negatively impacted parasite sensitivity to the delousing effects of these antiparasitics, especially among sea lice species. The NOTCH signaling pathway is a positive regulator of ABC transporter subfamily C expression and plays a key role in the generation and modulation of pesticide resistance. However, little is known about the molecular mechanisms behind pesticide resistance, partly due to the lack of genomic and molecular information on the processes involved in the resistance mechanism of sea lice. Next-generation sequencing technologies provide an opportunity for rapid and cost-effective generation of genome-scale data. The present study, through RNA-seq analysis, determined that the sea louse Caligus rogercresseyi (C. rogercresseyi) specifically responds to the delousing drugs azamethiphos and deltamethrin at the transcriptomic level by differentially activating mRNA of the NOTCH signaling pathway and of ABC genes. These results suggest that frequent antiparasitic application may increase the activity of inhibitory mRNA components, thereby promoting inhibitory NOTCH output and conditions for increased resistance to delousing drugs. Moreover, data analysis underscored that key functions of NOTCH/ABC components were regulated during distinct phases of the drug response, thus indicating resistance modifications in C. rogercresseyi resulting from the frequent use of organophosphates and pyrethroids. PMID:27187362

  15. Evidence for the Induction of Key Components of the NOTCH Signaling Pathway via Deltamethrin and Azamethiphos Treatment in the Sea Louse Caligus rogercresseyi.

    PubMed

    Boltaña, Sebastian; Chávez-Mardones, Jaqueline; Valenzuela-Muñoz, Valentina; Gallardo-Escárate, Cristian

    2016-01-01

    The extensive use of organophosphates and pyrethroids in the aquaculture industry has negatively impacted parasite sensitivity to the delousing effects of these antiparasitics, especially among sea lice species. The NOTCH signaling pathway is a positive regulator of ABC transporter subfamily C expression and plays a key role in the generation and modulation of pesticide resistance. However, little is known about the molecular mechanisms behind pesticide resistance, partly due to the lack of genomic and molecular information on the processes involved in the resistance mechanism of sea lice. Next-generation sequencing technologies provide an opportunity for rapid and cost-effective generation of genome-scale data. The present study, through RNA-seq analysis, determined that the sea louse Caligus rogercresseyi (C. rogercresseyi) specifically responds to the delousing drugs azamethiphos and deltamethrin at the transcriptomic level by differentially activating mRNA of the NOTCH signaling pathway and of ABC genes. These results suggest that frequent antiparasitic application may increase the activity of inhibitory mRNA components, thereby promoting inhibitory NOTCH output and conditions for increased resistance to delousing drugs. Moreover, data analysis underscored that key functions of NOTCH/ABC components were regulated during distinct phases of the drug response, thus indicating resistance modifications in C. rogercresseyi resulting from the frequent use of organophosphates and pyrethroids. PMID:27187362

  16. Stress response of Salmo salar (Linnaeus 1758) facing low abundance infestation of Caligus rogercresseyi (Boxshall & Bravo 2000), an object in the tank, and handling.

    PubMed

    González Gómez, M P; Marín Arribas, S L; Vargas-Chacoff, L

    2016-07-01

    This study looks at how low infestation loads of adult Caligus rogercresseyi and other stressors affect the physiology of Salmo salar. Experimental fish groups were with (infested) or without (control) exposure to the parasite. The parasite cohort was followed for 78 days post-infestation (dpi), and only adult lice were observed. Additional stressors were applied at 60 and 75 dpi. The analysis included measurements of fish physiology and weight. Low-level infestations by adult C. rogercresseyi for more than 50 dpi induced moderate stress in S. salar as well as a high energy demand and increased small skin mucous cells. Threshold lice loads were identified, and above those loads, a high stress response was observed. Additional stressors altered fish physiology, inducing downregulation of the cortisol response after the first stressor and upregulation after the second stressor, but infested fish responded more strongly. Parasitism by C. rogercresseyi is energetically demanding, affecting the primary and secondary responses (e.g. cortisol and glucose levels), as well as the tertiary response (fish weight). PMID:26644318

  17. Identification and Functional Expression of a Glutamate- and Avermectin-Gated Chloride Channel from Caligus rogercresseyi, a Southern Hemisphere Sea Louse Affecting Farmed Fish

    PubMed Central

    Niemeyer, María Isabel; Marabolí, Vanessa; González-Nilo, F. Danilo; Teulon, Jacques; Sepúlveda, Francisco V.; Cid, L. Pablo

    2014-01-01

    Parasitic sea lice represent a major sanitary threat to marine salmonid aquaculture, an industry accounting for 7% of world fish production. Caligus rogercresseyi is the principal sea louse species infesting farmed salmon and trout in the southern hemisphere. Most effective control of Caligus has been obtained with macrocyclic lactones (MLs) ivermectin and emamectin. These drugs target glutamate-gated chloride channels (GluCl) and act as irreversible non-competitive agonists causing neuronal inhibition, paralysis and death of the parasite. Here we report the cloning of a full-length CrGluClα receptor from Caligus rogercresseyi. Expression in Xenopus oocytes and electrophysiological assays show that CrGluClα is activated by glutamate and mediates chloride currents blocked by the ligand-gated anion channel inhibitor picrotoxin. Both ivermectin and emamectin activate CrGluClα in the absence of glutamate. The effects are irreversible and occur with an EC50 value of around 200 nM, being cooperative (nH = 2) for ivermectin but not for emamectin. Using the three-dimensional structure of a GluClα from Caenorabditis elegans, the only available for any eukaryotic ligand-gated anion channel, we have constructed a homology model for CrGluClα. Docking and molecular dynamics calculations reveal the way in which ivermectin and emamectin interact with CrGluClα. Both drugs intercalate between transmembrane domains M1 and M3 of neighbouring subunits of a pentameric structure. The structure displays three H-bonds involved in this interaction, but despite similarity in structure only of two these are conserved from the C. elegans crystal binding site. Our data strongly suggest that CrGluClα is an important target for avermectins used in the treatment of sea louse infestation in farmed salmonids and open the way for ascertaining a possible mechanism of increasing resistance to MLs in aquaculture industry. Molecular modeling could help in the design of new, more efficient

  18. Next-Generation Transcriptome Profiling of the Salmon Louse Caligus rogercresseyi Exposed to Deltamethrin (AlphaMax™): Discovery of Relevant Genes and Sex-Related Differences.

    PubMed

    Chávez-Mardones, Jacqueline; Gallardo-Escárate, Cristian

    2015-12-01

    Sea lice are one of the main parasites affecting the salmon aquaculture industry, causing significant economic losses worldwide. Increased resistance to traditional chemical treatments has created the need to find alternative control methods. Therefore, the objective of this study was to identify the transcriptome response of the salmon louse Caligus rogercresseyi to the delousing drug deltamethrin (AlphaMax™). Through bioassays with different concentrations of deltamethrin, adult salmon lice transcriptomes were sequenced from cDNA libraries in the MiSeq Illumina platform. A total of 78 million reads for females and males were assembled in 30,212 and 38,536 contigs, respectively. De novo assembly yielded 86,878 high-quality contigs and, based on published data, it was possible to annotate and identify relevant genes involved in several biological processes. RNA-seq analysis in conjunction with heatmap hierarchical clustering evidenced that pyrethroids modify the ectoparasitic transcriptome in adults, affecting molecular processes associated with the nervous system, cuticle formation, oxidative stress, reproduction, and metabolism, among others. Furthermore, sex-related transcriptome differences were evidenced. Specifically, 534 and 1033 exclusive transcripts were identified for males and females, respectively, and 154 were shared between sexes. For males, estradiol 17-beta-dehydrogenase, sphingolipid delta4-desaturase DES1, ketosamine-3-kinase, and arylsulfatase A, among others, were discovered, while for females, vitellogenin 1, glycoprotein G, transaldolase, and nitric oxide synthase were among those identified. The shared transcripts included annotations for tropomyosin, γ-crystallin A, glutamate receptor-metabotropic, glutathione S-transferase, and carboxipeptidase B. The present study reveals that deltamethrin generates a complex transcriptome response in C. rogercresseyi, thus providing valuable genomic information for developing new delousing drugs. PMID

  19. Transcriptome analysis of the couch potato (CPO) protein reveals an expression pattern associated with early development in the salmon louse Caligus rogercresseyi.

    PubMed

    Gallardo-Escárate, Cristian; Valenzuela-Muñoz, Valentina; Nuñez-Acuña, Gustavo; Chávez-Mardones, Jacqueline; Maldonado-Aguayo, Waleska

    2014-02-15

    The couch potato (CPO) protein is a key biomolecule involved in regulating diapause through the RNA-binding process of the peripheral and central nervous systems in insects and also recently discovered in a few crustacean species. As such, ectoparasitic copepods are interesting model species that have no evidence of developmental arrest. The present study is the first to report on the cloning of a putative CPO gene from the salmon louse Caligus rogercresseyi (CrCPO), as identified by high-throughput transcriptome sequencing. In addition, the transcription expression in larvae and adults was evaluated using quantitative real-time PCR. The CrCPO cDNA sequence showed 3261 base pairs (bp), consisting of 713bp of 5' UTR, 1741bp of 3' UTR, and an open reading frame of 807bp encoding for 268 amino acids. The highly conserved RNA binding regions RNP2 (LFVSGL) and RNP1 (SPVGFVTF), as well the dimerization site (LEF), were also found. Furthermore, eight single nucleotide polymorphisms located in the untranslated regions and one located in the coding region were detected. Gene transcription analysis revealed that CrCPO has ubiquitous expression across larval stages and in adult individuals, with the highest expression from nauplius to copepodid stages. The present study suggests a putative biological function of CrCPO associated with the development of the nervous system in salmon lice and contributes molecular evidence for candidate genes related to host-parasite interactions. PMID:24342663

  20. Sensitivity of Caligus rogercresseyi (Boxshall and Bravo 2000) to pyrethroids and azamethiphos measured using bioassay tests-A large scale spatial study.

    PubMed

    Marín, S L; Ibarra, R; Medina, M H; Jansen, P A

    2015-11-01

    The variety of antiparasitics that can be used against caligid copepods is limited and efforts are needed to maintain their efficacies. The objective of this study was to monitor the sensitivity of Caligus rogercresseyi, populations towards antiparasitics based on deltamethrin, cypermethrin and azamethiphos within and across geographic regions. The bioassay design consisted of exposing parasites collected from 23 farms to the different chemotherapeutants at the concentration and exposure times recommended for field treatment, under laboratory conditions, and evaluating the number of dead and live parasites 48h after exposure. Parasites were collected from 23 farms distributed in four macrozones in the Los Lagos region and three macrozones in the Aysén region. Parasite sensitivity was evaluated using a Generalized Linear Mixed Model of the Binomial family (Logit) fit by the maximum likelihood, using the lme4 package in R. Parasite gender, macrozone, and antiparasitics were used as fixed factors and farm was the random factor. The model including all the factors proved to be a useful tool for predicting parasite sensitivity. This approach identified (i) those macrozones with a greater likelihood of finding parasite populations which are more or less sensitive to the three antiparasitics, (ii) cases in which parasite sensitivity to the different antiparasitics varied within a given macrozone, (iii) differences in sensitivity between females and males and (iv) an important random effect associated with farm. The results indicate a spatial variability of parasite sensitivity to antiparasitics which, added to the continuous treatments applied on farms, suggest it is necessary to regularly update the sensitivity status in the macrozones. This would allow managers to improve their decision making processes regarding the type of antiparasitic to be used in a given situation. The one-concentration type bioassay performed in this study allowed us to perform a large spatial

  1. Three species of Caligus Müller, 1785 (Copepoda: Caligidae) parasitic on Caranx spp. (Teleostei: Carangidae) off Taiwan.

    PubMed

    Ho, Ju-Shey; Lin, Chin-Long

    2007-09-01

    Three species of sea-lice (Siphonostomatoida: Caligidae) parasitic on marine fishes of the genus Caranx off Taiwan are reported. They are: Caligus fortis Kabata, 1965 on Caranx ignobilis (Forsskål); Caligus robustus Bassett-Smith, 1898 on Caranx sexfasciatus Quoy & Gaimard; and Caligus inanis n. sp. on Caranx ignobilis. Caligus robustus is a widely distributed species, but this is the first report of C. fortis outside the Australian and Indian regions. The new species is distinguished from its congeners in lacking postantennal process and carrying a pair of tiny, tooth-like, sharp protuberances on the posterior margin of the cephalothoracic shield. PMID:17429578

  2. A new species of Caligus (Copepoda, Siphonostomatoida) from the plankton of the Caribbean coast of Venezuela with a key to species

    PubMed Central

    Suárez-Morales, Eduardo; Camisotti, Humberto; Martín, Alberto

    2012-01-01

    Abstract During a survey of the zooplankton community of Bahía Amuay, Venezuelan Caribbean, specimens of an undescribed species of Caligus Müller were collected. It resembles Caligus xystercus Cressey and Caligus ocyurus Cressey, both known only from the Caribbean Sea. The new species can be distinguished from these and other congeners by a combination of characters including the armature of legs 1 and 4, but mainly by its unique female genital complex. This is the first species of Caligus described from Venezuela. The species is described in full and a key to the species of the genus recorded in Venezuela is provided. PMID:22768004

  3. Chalimus stages of Caligus latigenitalis (Copepoda:Caligidae) parasitic on blackhead seabream from Japanese waters, with discussion of terminology used for developmental stages of caligids.

    PubMed

    Madinabeitia, Ione; Nagasawa, Kazuya

    2011-04-01

    The first and third chalimus stages and chalimus adult (previously known as young adult) of Caligus latigenitalis are described based on new material collected from the body surface of a heavily infected wild blackhead seabream Acanthopagrus schlegelii schlegelii from Hiroshima Bay, Japan. The second and fourth chalimus stages of the same species are redescribed. Adults of C. latigenitalis are characterized by possessing 2 stout marginally indented processes at the base of 2 terminal spines at distal exopodal segment of leg 4. The chalimi were identified to stage based on the structure of the frontal filament and the discrete ranges in body length. Sexual dimorphism is first observed at the third chalimus stage in the shape of the distal segment of the antenna. The total number of postnaupliar stages of C. latigenitalis is 6, including 4 semaphoronts, i.e., 1 copepodid stage consisting of 1 infective copepodid and the chalimus copepodid, 4 chalimus stages, and 1 adult stage with 1 chalimus adult and 1 mobile adult. New terminology for the developmental stages of caligid copepods is proposed herein by amending the definition of chalimus as the postnaupliar stages, as well as semaphoronts having a frontal filament for host attachment. PMID:21506770

  4. New records of sea lice (Copepoda: Caligidae) from marine fishes in Jaramijó, an area with potential for sea-cage aquaculture in Ecuador.

    PubMed

    Morales-Serna, Francisco Neptali; Caña-Bozada, Víctor; Mera-Loor, Geormery; Loor-Andrade, Peggy; Fajer-Ávila, Emma J; Ho, Ju-Shey

    2015-01-01

    Farming of finfish in sea cages is gaining popularity worldwide. These systems are a suitable environment for the emergence, establishment and transmission of parasites or pathogens, such as sea lice (Copepoda: Caligidae), known to cause serious diseases and economic losses in finfish aquaculture worldwide. In coastal waters of Jaramijó, Ecuador, there are plans to culture spotted rose snapper (Lutjanus guttatus) and longfin yellowtail (Seriola rivoliana); however, the information about the occurrence of sea lice on fish from this country is scarce. To address this problem, a parasitological survey of economically important fish caught by artisanal fishermen was conducted between June 2013 and May 2014. A total of 608 fish belonging to 66 species were examined. Sea lice were found on 23 fish species. The diversity of these parasites consisted of 22 species of Caligus and 5 species of Lepeophtheirus. Most sea lice species (66%) occurred in a single fish species only, with low infection levels. The most frequently encountered species were Caligus asperimanus Pearse, 1951, Caligus mutabilis Wilson, 1905 and Caligus rufimaculatus Wilson, 1905. Taxonomic remarks are presented for some of the species recorded during this survey. All but two sea lice records are new to Ecuador, considerably expanding the geographical range of some species. PMID:25781254

  5. Complete mitochondrial genome of Sinergasilus polycolpus (Copepoda:Poecilostomatoida).

    PubMed

    Feng, Han-Li; Wang, Li-Xia; Huang, Jinyan; Jiang, Jinbin; Tang, Dunping; Fang, Rui; Su, Ying-Bing

    2016-07-01

    The full mitochondrial (mt) genome of Sinergasilus polycolpus is 14 000 bp in length, and it contains 13 protein-coding genes, 22 transfer RNA genes, 2 rRNA genes and 1 non-coding region. The genome organization, nucleotide composition and codon usage are different compared to other Copepodas, such as Lernaea cyprinacea. The full mt genome of S. polycolpus provides useful information for further studies on epidemiology and phylogenetics. PMID:26152348

  6. Sea lice, Caligus rotundigenitalis infestations and its management in pond cultured pearlspot, Etroplus suratensis in Gujarat: a case study.

    PubMed

    Solanki, Haresh G; Patil, Prasanna Kumar; Vanza, Jesing G; Patel, Pritesh; Sethi, Satyanarayana; Gopal, Chavali

    2016-06-01

    Highly popular and delicious fish of Kerala (India), pearlspot, Etroplus suratensis is known for its ability to tolerate wide range of salinity, omnivorous feeding behavior. Present report documents the occurrence and management of Caligus rotundigenitalis in brackishwater pond meant for culture demonstration of pearlspot in Gujarat, (India). A brackishwater aquaculture pond (1,500 sq m) was stocked with pearlspot fry (2.60 ± 0.83 g; 4.31 ± 0.82 cm) @ 25,000 ha(-1). On the 46th day of culture couple of dead fish were observed which gradually increased to 120 per day by 52nd day. Following the close observation parasitic infestation was noticed on gills cavities ranging from 15 to 20 numbers per fish. These characteristic features confirmed the parasite as C. rotundigenitalis. As a therapeutic measure the infested pond was successfully treated with Butox(®) @ 300 ml/ha (Deltamethrin 12.5 mg) and repeat dose was administered 2 weeks later. The results of the study suggest the possible therapeutic value of Deltamethrin in treatment of caligid infestation in pond cultured pearlspot. PMID:27413343

  7. Microcrustaceans (Branchipoda and Copepoda) of Wetland Impoundments on the Savannah River Site, Aiken, South Carolina

    SciTech Connect

    DeBiase, Adrienne E; Taylor, Barbara E

    2005-09-21

    The United States Department of Energy’s Savannah River Site (SRS) in Aiken, Allendale, and Barnwell Counties, South Carolina, contains an abundance of freshwater wetlands and impoundments. Four large impoundments, as well as several small, abandoned farm and mill ponds, and about 400 Carolina bays and other small, isolated depression wetland ponds are located within the 893 km2 area of the SRS. Crustaceans of the orders Branchiopoda and Copepoda are nearly ubiquitous in these water bodies. Although small in size, these organisms are often very abundant. They consequently play an important trophic role in freshwater food webs supporting fish, larval salamanders, larval insects, and numerous other animals, aquatic and terrestrial. This report provides an introduction to the free-living microcrustaceans of lentic water bodies on the SRS and a comprehensive list of species known to occur there. Occurrence patterns are summarized from three extensive survey studies, supplemented with other published and unpublished records. In lieu of a key, we provide a guide to taxonomic resources and notes on undescribed species. Taxa covered include the orders Cladocera, Anostraca, Laevicaudata, and Spinicaudata of the Subclass Branchiopoda and the Superorders Calanoida and Cyclopoida of Subclass Copepoda. Microcrustaceans of the Superorder Harpacticoida of the Subclass Copepoda and Subclass Ostracoda are also often present in lentic water bodies. They are excluded from this report because they have not received much study at the species level on the SRS.

  8. Screening of candidate genes encoding proteins expressed in pectoral fins of fugu Takifugu rubripes, in relation to habitat site of parasitic copepod Caligus fugu, using suppression subtractive hybridization.

    PubMed

    Tasumi, Satoshi; Norshida, Ismail; Boxshall, Geoffrey A; Kikuchi, Kiyoshi; Suzuki, Yuzuru; Ohtsuka, Susumu

    2015-05-01

    Caligus fugu is a parasitic copepod specific to the tetraodontid genus Takifugu including the commercially important Takifugu rubripes. Despite the rapid accumulation of knowledge on other aspects of its biology, the host and settlement-site recognition mechanisms of this parasite are not yet well understood. Since the infective copepodid stage shows preferential site selection in attaching to the fins, we considered it likely that the copepodid recognizes chemical cues released or leaking from the fins, and/or transmembrane protein present on the fins. To isolate molecules potentially related to attachment site specificity, we applied suppression subtractive hybridization (SSH) PCR by identifying genes expressed more highly in pectoral fins of T. rubripes than in the body surface skin. We sequenced plasmid DNA from 392 clones in a SSH library. The number of non-redundant sequences was 276, which included 135 sequences located on 117 annotated genes and 141 located in positions where no genes had been annotated. We characterized those annotated genes on the basis of gene ontology terms, and found that 46 of the identified genes encode secreted proteins, enzymes or membrane proteins. Among them nine showed higher expression in the pectoral fins than in the skin. These could be candidate genes for involvement in behavioral mechanisms related to the site specificity shown by the infective copepodids of C. fugu. PMID:25731921

  9. Akirins in sea lice: first steps towards a deeper understanding.

    PubMed

    Carpio, Yamila; García, Claudia; Pons, Tirso; Haussmann, Denise; Rodríguez-Ramos, Tania; Basabe, Liliana; Acosta, Jannel; Estrada, Mario Pablo

    2013-10-01

    Sea lice (Copepoda, Caligidae) are the most widely distributed marine pathogens in the salmon industry. Vaccination could be an environmentally friendly alternative for sea lice control; however, research on the development of such vaccines is still at an early stage of development. Recent results have suggested that subolesin/akirin/my32 are good candidate antigens for the control of arthropod infestations, including sea lice, but background knowledge about these genes in crustaceans is limited. Herein, we characterize the my32 gene/protein from two important sea lice species, Caligus rogercresseyi and Lepeophtheirus salmonis, based on cDNA sequence isolation, phylogenetic relationships, three dimensional structure prediction and expression analysis. The results show that these genes/proteins have the main characteristics of akirins from invertebrates. In addition, immunization with purified recombinant my32 from L. salmonis elicited a specific antibody response in mice and fish. These results provide an improvement to our current knowledge about my32 proteins and their potential use as vaccine candidates against sea lice in fish. PMID:23850998

  10. Microcrustaceans (Branchiopoda and Copepoda) of Wetland Ponds and Impoundments on the Savannah River Site, Aiken, South Carolina

    SciTech Connect

    Adrienne E. DeBiase; Barbara E. Taylor

    2005-09-21

    The United States Department of Energy's Savannah River Site (SRS) in Aiken, Allendale, and Barnwell Counties, South Carolina, contains an abundance of freshwater wetlands and impoundments. Four large impoundments, as well as several small, abandoned farm and mill ponds, and about 400 Carolina bays and other small, isolated depression wetland ponds are located within the 893 km2 area of the SRS. Crustaceans of the orders Branchiopoda and Copepoda are nearly ubiquitous in these water bodies. Although small in size, these organisms are often very abundant. They consequently play an important trophic role in freshwater food webs supporting fish, larval salamanders, larval insects, and numerous other animals, aquatic and terrestrial. This report provides an introduction to the free-living microcrustaceans of lentic water bodies on the SRS and a comprehensive list of species known to occur there. Occurrence patterns are summarized from three extensive survey studies, supplemented with other published and unpublished records. In lieu of a key, we provide a guide to taxonomic resources and notes on undescribed species. Taxa covered include the orders Cladocera, Anostraca, Laevicaudata, and Spinicaudata of the Subclass Branchiopoda and the Superorders Calanoida and Cyclopoida of Subclass Copepoda. Microcrustaceans of the Superorder Harpacticoida of the Subclass Copepoda and Subclass Ostracoda are also often present in lentic water bodies. They are excluded from this report because they have not received much study at the species level on the SRS.

  11. Phylogenetic Information Content of Copepoda Ribosomal DNA Repeat Units: ITS1 and ITS2 Impact

    PubMed Central

    Zagoskin, Maxim V.; Lazareva, Valentina I.; Grishanin, Andrey K.; Mukha, Dmitry V.

    2014-01-01

    The utility of various regions of the ribosomal repeat unit for phylogenetic analysis was examined in 16 species representing four families, nine genera, and two orders of the subclass Copepoda (Crustacea). Fragments approximately 2000 bp in length containing the ribosomal DNA (rDNA) 18S and 28S gene fragments, the 5.8S gene, and the internal transcribed spacer regions I and II (ITS1 and ITS2) were amplified and analyzed. The DAMBE (Data Analysis in Molecular Biology and Evolution) software was used to analyze the saturation of nucleotide substitutions; this test revealed the suitability of both the 28S gene fragment and the ITS1/ITS2 rDNA regions for the reconstruction of phylogenetic trees. Distance (minimum evolution) and probabilistic (maximum likelihood, Bayesian) analyses of the data revealed that the 28S rDNA and the ITS1 and ITS2 regions are informative markers for inferring phylogenetic relationships among families of copepods and within the Cyclopidae family and associated genera. Split-graph analysis of concatenated ITS1/ITS2 rDNA regions of cyclopoid copepods suggested that the Mesocyclops, Thermocyclops, and Macrocyclops genera share complex evolutionary relationships. This study revealed that the ITS1 and ITS2 regions potentially represent different phylogenetic signals. PMID:25215300

  12. The sea louse Lepeophtheirus acutus (Caligidae, Siphonostomatoida, Copepoda) as a pathogen of aquarium-held elasmobranchs.

    PubMed

    Kik, M J L; Janse, M; Benz, G W

    2011-10-01

    Lepeophtheirus acutus Heegaard, 1943 (Caligidae, Siphonostomatoida, Copepoda), was collected from or observed on four of six elasmobranch species held at Burgers' Zoo (Arnhem, The Netherlands). Circumstantial evidence suggested that a zebra shark, Stegostoma fasciatum (Hermann), from the wild carried the infection into the facility, where copepods reproduced and colonized additional hosts. Copepods typically attached on and about the eyes, in the mouth and occasionally about the cloaca and on the claspers. Severe ocular lesions were associated with infections on zebra sharks, a grey reef shark, Carcharhinus amblyrhynchos (Bleeker), whitetip reef sharks, Triaenodon obesus (Rüppell), and giant shovelnose ray, Rhinobatos typus Bennett, while blacktip reef sharks, Carcharhinus melanopterus (Quoy & Gaimard), and blacktip sharks, Carcharhinus limbatus (Valenciennes), living in infested aquaria showed no sign of infection. Water treatments using trichlorfon were considered primarily responsible for the eradication of copepods from hosts and infested aquaria. This case is the first report of a copepod infection being closely associated with disease and death of an aquarium-held elasmobranch. Given its ability to infect a wide variety of elasmobranchs and promote life-threatening lesions on some hosts, L. acutus should be considered a dangerous pathogen of captive elasmobranchs. PMID:21916904

  13. Establishment of two invasive crustaceans (Copepoda: Harpacticoida) on the nearshore sands of Lake Michigan

    USGS Publications Warehouse

    Horvath, Thomas G.; Whitman, Richard L.; Last, Laurel L.

    2001-01-01

    Benthic copepods (Copepoda: Harpacticoida) in the nearshore sediments of southern Lake Michigan appear to be dominated by two new invasive species. We report the first occurrence in North America of Schizopera borutzkyi Montschenko, a native to the Danube River delta, and Heteropsyllus nr. nunni, likely a new species that is morphologically similar to the marine species Heteropsyllus nunni and represents the first occurrence of this genus in freshwater. Schizopera borutzkyi is a euryhaline species occurring in shallow sands in its native habitat and in deeper sands (6-15 m) in southern Lake Michigan. Based on the absence of these species from previous studies, we suggest that they are recent introductions. Heteropsyllus nr. nunni dominated (55-100%) the harpacticoid abundance to depths of 9 m, but S. borutzkyi comprised 75% of the harpacticoid abundance at 15 m. Native harpacticoids were always greatly outnumbered by invasive harpacticoids in our samples, which suggests that the natives are being replaced rapidly or that the invasive species are finding unused resources. The ecological implications of these introductions are not known, but these invasions may represent continued 'invasional meltdown' in Lake Michigan.

  14. Space-time cluster analysis of sea lice infestation (Caligus clemensi and Lepeophtheirus salmonis) on wild juvenile Pacific salmon in the Broughton Archipelago of Canada.

    PubMed

    Patanasatienkul, Thitiwan; Sanchez, Javier; Rees, Erin E; Pfeiffer, Dirk; Revie, Crawford W

    2015-06-15

    Sea lice infestation levels on wild chum and pink salmon in the Broughton Archipelago region are known to vary spatially and temporally; however, the locations of areas associated with a high infestation level had not been investigated yet. In the present study, the multivariate spatial scan statistic based on a Poisson model was used to assess spatial clustering of elevated sea lice (Caligus clemensi and Lepeophtheirus salmonis) infestation levels on wild chum and pink salmon sampled between March and July of 2004 to 2012 in the Broughton Archipelago and Knight Inlet regions of British Columbia, Canada. Three covariates, seine type (beach and purse seining), fish size, and year effect, were used to provide adjustment within the analyses. The analyses were carried out across the five months/datasets and between two fish species to assess the consistency of the identified clusters. Sea lice stages were explored separately for the early life stages (non-motile) and the late life stages of sea lice (motile). Spatial patterns in fish migration were also explored using monthly plots showing the average number of each fish species captured per sampling site. The results revealed three clusters for non-motile C. clemensi, two clusters for non-motile L. salmonis, and one cluster for the motile stage in each of the sea lice species. In general, the location and timing of clusters detected for both fish species were similar. Early in the season, the clusters of elevated sea lice infestation levels on wild fish are detected in areas closer to the rivers, with decreasing relative risks as the season progresses. Clusters were detected further from the estuaries later in the season, accompanied by increasing relative risks. In addition, the plots for fish migration exhibit similar patterns for both fish species in that, as expected, the juveniles move from the rivers toward the open ocean as the season progresses The identification of space-time clustering of infestation on wild

  15. Taxonomic Resolutions Based on 18S rRNA Genes: A Case Study of Subclass Copepoda

    PubMed Central

    Wu, Shu; Xiong, Jie; Yu, Yuhe

    2015-01-01

    Biodiversity studies are commonly conducted using 18S rRNA genes. In this study, we compared the inter-species divergence of variable regions (V1–9) within the copepod 18S rRNA gene, and tested their taxonomic resolutions at different taxonomic levels. Our results indicate that the 18S rRNA gene is a good molecular marker for the study of copepod biodiversity, and our conclusions are as follows: 1) 18S rRNA genes are highly conserved intra-species (intra-species similarities are close to 100%); and could aid in species-level analyses, but with some limitations; 2) nearly-whole-length sequences and some partial regions (around V2, V4, and V9) of the 18S rRNA gene can be used to discriminate between samples at both the family and order levels (with a success rate of about 80%); 3) compared with other regions, V9 has a higher resolution at the genus level (with an identification success rate of about 80%); and 4) V7 is most divergent in length, and would be a good candidate marker for the phylogenetic study of Acartia species. This study also evaluated the correlation between similarity thresholds and the accuracy of using nuclear 18S rRNA genes for the classification of organisms in the subclass Copepoda. We suggest that sample identification accuracy should be considered when a molecular sequence divergence threshold is used for taxonomic identification, and that the lowest similarity threshold should be determined based on a pre-designated level of acceptable accuracy. PMID:26107258

  16. Morphometric variability of Arctodiaptomus salinus (Copepoda) in the Mediterranean-Black Sea region

    PubMed Central

    ANUFRIIEVA, Elena V.; SHADRIN, Nickolai V.

    2015-01-01

    Inter-species variability in morphological traits creates a need to know the range of variability of characteristics in the species for taxonomic and ecological tasks. Copepoda Arctodiaptomus salinus, which inhabits water bodies across Eurasia and North Africa, plays a dominant role in plankton of different water bodies-from fresh to hypersaline. This work assesses the intra- and inter-population morphometric variability of A. salinus in the Mediterranean-Black Sea region and discusses some observed regularities. The variability of linear body parameters and proportions was studied. The impacts of salinity, temperature, and population density on morphological characteristics and their variability can manifest themselves in different ways at the intra- and inter-population levels. A significant effect of salinity, pH and temperature on the body proportions was not found. Their intra-population variability is dependent on temperature and salinity. Sexual dimorphism of A. salinus manifests in different linear parameters, proportions, and their variability. There were no effects of temperature, pH and salinity on the female/male parameter ratio. There were significant differences in the body proportions of males and females in different populations. The influence of temperature, salinity, and population density can be attributed to 80%-90% of intra-population variability of A. salinus. However, these factors can explain less than 40% of inter-population differences. Significant differences in the body proportions of males and females from different populations may suggest that some local populations of A. salinus in the Mediterranean-Black Sea region are in the initial stages of differentiation. PMID:26646569

  17. Morphometric variability of Arctodiaptomus salinus (Copepoda) in the Mediterranean-Black Sea region.

    PubMed

    Anufriieva, Elena V; Shadrin, Nickolai V

    2015-11-18

    Inter-species variability in morphological traits creates a need to know the range of variability of characteristics in the species for taxonomic and ecological tasks. Copepoda Arctodiaptomus salinus, which inhabits water bodies across Eurasia and North Africa, plays a dominant role in plankton of different water bodies-from fresh to hypersaline. This work assesses the intra- and inter-population morphometric variability of A. salinus in the Mediterranean-Black Sea region and discusses some observed regularities. The variability of linear body parameters and proportions was studied. The impacts of salinity, temperature, and population density on morphological characteristics and their variability can manifest themselves in different ways at the intra- and inter-population levels. A significant effect of salinity, pH and temperature on the body proportions was not found. Their intra-population variability is dependent on temperature and salinity. Sexual dimorphism of A. salinus manifests in different linear parameters, proportions, and their variability. There were no effects of temperature, pH and salinity on the female/male parameter ratio. There were significant differences in the body proportions of males and females in different populations. The influence of temperature, salinity, and population density can be attributed to 80%-90% of intra-population variability of A. salinus. However, these factors can explain less than 40% of inter-population differences. Significant differences in the body proportions of males and females from different populations may suggest that some local populations of A. salinus in the Mediterranean-Black Sea region are in the initial stages of differentiation. PMID:26646569

  18. Diversity of the free-living marine and freshwater Copepoda (Crustacea) in Costa Rica: a review

    PubMed Central

    Morales-Ramírez, Álvaro; Suárez-Morales, Eduardo; Corrales-Ugalde, Marco; Garrote, Octavio Esquivel

    2014-01-01

    Abstract 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

  19. A new species of Centropages (Copepoda: Calanoida: Centropagidae) from the central Red Sea based on morphological and molecular evidence.

    PubMed

    El-Sherbiny, Mohsen M; Al-Aidaroos, Ali M

    2015-01-01

    Centropages mohamedi sp. nov. (Copepoda: Calanoida) is described from specimens collected in zooplankton samples off Obhur Creek on the Saudi Arabian coast of the central Red Sea. The new species is most closely related to C. orsinii Giesbrecht, 1889, a species described from the Red Sea and widely distributed in the neritic waters of the Indo-West Pacific region. The new species is mainly distinguished by the female genital double somite, male antennules, male leg 4, and leg 5 of both sexes. DNA sequences of the mitochondrial cytochrome C oxidase subunit one (mtCOI) of the two species differ by 20.8%, supporting their morphology-based identification as distinct species.  PMID:25661620

  20. Harpacticoida (Copepoda) fauna and the taxocenes structure of brackish lagoons and estuaries of the Russian far east

    NASA Astrophysics Data System (ADS)

    Chertoprud, E. S.; Frenkel, S. E.; Novichkova, A. A.; Vodop'yanov, S. S.

    2014-11-01

    On the basis of original data and literature sources, the species composition of Harpacticoida (Copepoda) in the plankton of the brackish waters of four Far Eastern regions was described: Khabarovsk krai, Sakhalin Island, Kamchatka Peninsula, and the Commander Islands. The compiled list includes 32 harpacticoid species of 22 genera and 10 families. The representatives of the typical brackish families Canthocamptidae and Ectinosomatidae account for about one-third of the total. Six of the species are new to science: 4 species of Halectinosoma, Amphiascus sp. 1, and Schizopera sp. 1. Cosmopolitan species constitute the major portion of the fauna (38% of the total number), while a smaller proportion is typical of endemics (25%), as well as species with the arctic (12%), tropical (9%), and North American (9%) types of areas. There are 17 types of harpacticoid taxocenes of the observed water bodies. Also, the influence of the salinity and temperature on these species complexes was characterized. The hypotheses about the cosmopolitanism of the brackish water fauna and the intrazonality of the estuarine harpacticoid taxocenes structure were tested. It is shown that the structure of the genera dominance in the taxocenes allocated for the temperature latitudes of the Far East demonstrates significant similarity with the arctic and tropical regions.

  1. The complete mitogenome of the whale shark parasitic copepod Pandarus rhincodonicus norman, Newbound & Knott (Crustacea; Siphonostomatoida; Pandaridae)--a new gene order for the copepoda.

    PubMed

    Austin, Christopher M; Tan, Mun Hua; Lee, Yin Peng; Croft, Laurence J; Meekan, Mark G; Pierce, Simon J; Gan, Han Ming

    2016-01-01

    The complete mitochondrial genome of the parasitic copepod Pandarus rhincodonicus was obtained from a partial genome scan using the HiSeq sequencing system. The Pandarus rhincodonicus mitogenome has 14,480 base pairs (62% A+T content) made up of 12 protein-coding genes, 2 ribosomal subunit genes, 22 transfer RNAs, and a putative 384 bp non-coding AT-rich region. This Pandarus mitogenome sequence is the first for the family Pandaridae, the second for the order Siphonostomatoida and the sixth for the Copepoda. PMID:24779605

  2. Advances in Taxonomy, Ecology, and Biogeography of Dirivultidae (Copepoda) Associated with Chemosynthetic Environments in the Deep Sea

    PubMed Central

    Gollner, Sabine; Ivanenko, Viatcheslav N.; Arbizu, Pedro Martínez; Bright, Monika

    2010-01-01

    Background Copepoda is one of the most prominent higher taxa with almost 80 described species at deep-sea hydrothermal vents. The unique copepod family Dirivultidae with currently 50 described species is the most species rich invertebrate family at hydrothermal vents. Methodology/Principal Findings We reviewed the literature of Dirivultidae and provide a complete key to species, and map geographical and habitat specific distribution. In addition we discuss the ecology and origin of this family. Conclusions/Significance Dirivultidae are only present at deep-sea hydrothermal vents and along the axial summit trough of midocean ridges, with the exception of Dirivultus dentaneus found associated with Lamellibrachia species at 1125 m depth off southern California. To our current knowledge Dirivultidae are unknown from shallow-water vents, seeps, whale falls, and wood falls. They are a prominent part of all communities at vents and in certain habitat types (like sulfide chimneys colonized by pompei worms) they are the most abundant animals. They are free-living on hard substrate, mostly found in aggregations of various foundation species (e.g. alvinellids, vestimentiferans, and bivalves). Most dirivultid species colonize more than one habitat type. Dirivultids have a world-wide distribution, but most genera and species are endemic to a single biogeographic region. Their origin is unclear yet, but immigration from other deep-sea chemosynthetic habitats (stepping stone hypothesis) or from the deep-sea sediments seems unlikely, since Dirivultidae are unknown from these environments. Dirivultidae is the most species rich family and thus can be considered the most successful taxon at deep-sea vents. PMID:20838422

  3. Multi-Gene Analysis Reveals a Lack of Genetic Divergence between Calanus agulhensis and C. sinicus (Copepoda; Calanoida)

    PubMed Central

    Kozol, Robert; Blanco-Bercial, Leocadio; Bucklin, Ann

    2012-01-01

    The discrimination and taxonomic identification of marine species continues to pose a challenge despite the growing number of diagnostic metrics and approaches. This study examined the genetic relationship between two sibling species of the genus Calanus (Crustacea; Copepoda; Calanidae), C. agulhensis and C. sinicus, using a multi-gene analysis. DNA sequences were determined for portions of the mitochondrial cytochrome c oxidase I (mtCOI); nuclear citrate synthase (CS), and large subunit (28S) rRNA genes for specimens collected from the Sea of Japan and North East (NE) Pacific Ocean for C. sinicus and from the Benguela Current and Agulhas Bank, off South Africa, for C. agulhensis. For mtCOI, C. sinicus and C. agulhensis showed similar levels of haplotype diversity (Hd = 0.695 and 0.660, respectively) and nucleotide diversity (π = 0.003 and 0.002, respectively). Pairwise FST distances for mtCOI were significant only between C. agulhensis collected from the Agulhas and two C. sinicus populations: the Sea of Japan (FST = 0.152, p<0.01) and NE Pacific (FST = 0.228, p<0.005). Between the species, FST distances were low for both mtCOI (FST = 0.083, p = 0.003) and CS (FST = 0.050, p = 0.021). Large subunit (28S) rRNA showed no variation between the species. Our results provide evidence of the lack of genetic distinction of C. sinicus and C. agulhensis, raise questions of whether C. agulhensis warrants status as a distinct species, and indicate the clear need for more intensive and extensive ecological and genetic analysis. PMID:23118849

  4. Life-cycle of Choniomyzon inflatus Wakabayashi, Otake, Tanaka & Nagasawa, 2013 (Copepoda: Siphonostomatoida: Nicothoidae) with the morphological descriptions of the nauplius, copepodid and adult male.

    PubMed

    Otake, Shusaku; Wakabayashi, Kaori; Tanaka, Yuji; Nagasawa, Kazuya

    2016-02-01

    Choniomyzon inflatus Wakabayashi, Otake, Tanaka & Nagasawa, 2013 (Copepoda: Siphonostomatoida: Nicothoidae), an associate of the scyllarid lobster Ibacus novemdentatus Gibbes, was found to pass through at least four developmental stages: nauplius, copepodid I (CI), copepodid II or later (CII+) and adult. Free-living nauplii were observed hatching from the ovisacs of adult females. CI was found on the body surface of both female and male hosts, whereas CII+ and adult were obtained from the female host's egg masses. The life-cycle of this copepod is presumed to be as follows: (i) nauplius develops into CI in the water column; (ii) infective CI settles on body surface of host; (iii) CI moults into the following stage, changing its microhabitat from host's body surface to egg masses; (iv) CII+ develops on egg masses of host until adult stage; and (v) adult female and male mate on the host's egg masses. PMID:26790679

  5. A new species of Eurycletodes Sars, 1909 (Copepoda: Harpacticoida: Argestidae) from the southern hemisphere including remarks on the phylogeny of the genus and its subgenera

    NASA Astrophysics Data System (ADS)

    Menzel, Lena

    2011-12-01

    This paper deals with taxonomy and phylogenetics of the genus Eurycletodes Sars, 1909 (Copepoda: Harpacticoida: Argestidae). Samples, collected from the southeast Atlantic on board RV "Meteor" during the cruises DIVA-1 (M48/1) and DIVA-2 (M63/2), contain specimens of Eurycletodes. Eurycletodes is characterized as a monophylum by A1 segments III + IV fused, basal seta of md palp lost, exp of md palp reduced to 1 seta or completely lost. Similarly, the subgenera Eurycletodes (Eurycletodes) and Eurycletodes (Oligocletodes) are characterized as monophyletic by the loss of the inner seta on P1 exp2 (apomorphic to E. (E.)) and the absence of the inner seta on P5 endopodal lobe (apomorphic to E. (O.)). Eurycletodes profundus is renamed as E. (O.) profundus. Eurycletodes ephippiger is the only species of the genus without subgeneric designation. Eurycletodes (O.) diva sp. nov. is described. The new species differs from described species of the genus by a larger body size, P5 endopodal lobe only slightly protruding, last segment of A1 with 2 outer setae, furcal rami elongated between setae VII and IV. The occurrence of 2 specimens of Eurycletodes (O.) diva sp. nov. at 2 sites separated by the Walvis Ridge supports the hypothesis that geographic obstacles do not prevent harpacticoid copepods from spreading in the deep sea.

  6. Molecular systematic of three species of Oithona (Copepoda, Cyclopoida) from the Atlantic Ocean: comparative analysis using 28S rDNA.

    PubMed

    Cepeda, Georgina D; Blanco-Bercial, Leocadio; Bucklin, Ann; Berón, Corina M; Viñas, María D

    2012-01-01

    Species of Oithona (Copepoda, Cyclopoida) are highly abundant, ecologically important, and widely distributed throughout the world oceans. Although there are valid and detailed descriptions of the species, routine species identifications remain challenging due to their small size, subtle morphological diagnostic traits, and the description of geographic forms or varieties. This study examined three species of Oithona (O. similis, O. atlantica and O. nana) occurring in the Argentine sector of the South Atlantic Ocean based on DNA sequence variation of a 575 base-pair region of 28S rDNA, with comparative analysis of these species from other North and South Atlantic regions. DNA sequence variation clearly resolved and discriminated the species, and revealed low levels of intraspecific variation among North and South Atlantic populations of each species. The 28S rDNA region was thus shown to provide an accurate and reliable means of identifying the species throughout the sampled domain. Analysis of 28S rDNA variation for additional species collected throughout the global ocean will be useful to accurately characterize biogeographical distributions of the species and to examine phylogenetic relationships among them. PMID:22558245

  7. Effect of temperature and salinity on egg hatching and description of the life cycle of Lernanthropus latis (Copepoda: Lernanthropidae) infecting barramundi, Lates calcarifer.

    PubMed

    Brazenor, Alexander K; Hutson, Kate S

    2013-10-01

    The parasite Lernanthropus latis (Copepoda: Lernanthropidae) is a major threat to the sustained mariculture of barramundi, Lates calcarifer (Perciformes: Latidae). We investigated the effect of water temperature and salinity on egg hatching success of L. latis and describe the life cycle for the first time. Wild and sea-caged L. calcarifer examined in tropical north Australia exhibited similar parasite prevalence (range: 80-100%) and mean parasite intensity (range: 3-6), whereas land-based maricultured fish were not infected. Hatching success and time to first and last hatch was determined for a range of water temperature (22, 30, 32 and 34°C) and salinity (0, 11, 22, 35 and 40‰) combinations representing current and predicted climate conditions. There was a significant interaction between water temperature and salinity on the hatching success of L. latis nauplii. Eggs hatched in all temperature treatments, with the greatest hatching success at 30°C and 32°C (98 and 92% success, respectively) in 35‰. Hatching did not occur at 0‰ and was severely reduced at 11‰ (1.6% success). Hatching began within 6h at all water temperatures with >95% of eggs hatched within 30h at 30, 32 and 34°C and within 60h at 22°C. Adult parasites differed from the original description by the presence of the parabasal flagellum, small setae on the legs and caudal rami and minor incongruences regarding morphological measurements. The life cycle of L. latis includes three free living stages and five parasitic stages. Although L. latis exhibits broad environmental tolerance, freshwater can be used as an effective management strategy to break the life cycle in aquaculture. PMID:23707229

  8. Sagum posteli Delamare-Deboutteville & Nunes-Ruivo, 1954 (Copepoda: Siphonostomatoida: Lernanthropidae) parasitic on Epinephelus aeneus (Geoffroy Saint-Hilaire) in Turkish waters, with a key to the species of Sagum Wilson, 1913.

    PubMed

    Toksen, Erol; Boxshall, Geoffrey A; Altinozek, Sidika

    2012-05-01

    Sagum posteli Delamare-Deboutteville & Nunes-Ruivo, 1954 (Copepoda: Lernanthropidae) is reported from the white grouper Epinephelus aeneus Geoffroy Saint-Hilaire caught off the Turkish Mediterranean coast. This documents the first discovery of this species in the Mediterranean and is only the second record. The species is redescribed from adult females and the cephalothoracic limbs are described for the first time. The valid species of the genus Sagum Wilson, 1913 are reviewed, and the poorly described species S. poeyi Ortiz, Lalana & Suarez, 2003 is relegated as a junior synonym of S. texanum Pearse, 1952, described from the same host. A key is provided to females of the ten valid species of Sagum and the known hosts for all species are summarised. PMID:22488434

  9. Diversity of the Monstrilloida (Crustacea: Copepoda)

    PubMed Central

    Suárez-Morales, Eduardo

    2011-01-01

    Monstrilloid copepods are protelean parasites of different groups of marine benthic invertebrates. Only their first naupliar, preadult, and adult phases are planktonic. Monstrilloids are currently represented by more than 115 nominal species contained in four genera. Its taxonomic knowledge has been hampered by nomenclatural and descriptive problems derived from their peculiar ontogeny and poor definitions of taxa. One of the most important difficulties is that of matching males to females. The only reliable methods to link the sexes of a species are the confirmation of particular apomorphies shared by both sexes, finding both sexes in the same host or as a pre-copulatory male-female pair in the plankton, or by the use of molecular markers. A general overview of the morphology of the group and its life cycle is provided herein. Recently, upgraded descriptive standards have been established and the relevance of redescribing taxa based on type and museum specimens has been demonstrated. The rate of species description per decade has had several peaks between 1840 and 2010: (1971–1980, 1991–2000, 2001–2010), each related to the activity of a few researchers. An analysis of the world distribution of published records of the Monstrilloida revealed that the Northeast Atlantic is the best studied region (45% of all records), followed by the Northwestern Atlantic (17%); the least surveyed areas include regions of the southern hemisphere (less than 3%). The Northeast Atlantic region harbors the highest number of known species (32 nominal species), followed by the Caribbean Sea/Gulf of Mexico (24), the Mediterranean/Black Sea (19), Indonesia-Malaysia-Philippines region (17), Japanese waters (17), and the Brazil-Argentina area (16). Other than these generalized patterns, little can be concluded concerning the biogeography of the group. Many species records are doubtful or improbable, and purportedly cosmopolitan nominal species are being revealed as species complexes yet to be studied. PMID:21853055

  10. Diversity of the Monstrilloida (Crustacea: Copepoda).

    PubMed

    Suárez-Morales, Eduardo

    2011-01-01

    Monstrilloid copepods are protelean parasites of different groups of marine benthic invertebrates. Only their first naupliar, preadult, and adult phases are planktonic. Monstrilloids are currently represented by more than 115 nominal species contained in four genera. Its taxonomic knowledge has been hampered by nomenclatural and descriptive problems derived from their peculiar ontogeny and poor definitions of taxa. One of the most important difficulties is that of matching males to females. The only reliable methods to link the sexes of a species are the confirmation of particular apomorphies shared by both sexes, finding both sexes in the same host or as a pre-copulatory male-female pair in the plankton, or by the use of molecular markers. A general overview of the morphology of the group and its life cycle is provided herein. Recently, upgraded descriptive standards have been established and the relevance of redescribing taxa based on type and museum specimens has been demonstrated. The rate of species description per decade has had several peaks between 1840 and 2010: (1971-1980, 1991-2000, 2001-2010), each related to the activity of a few researchers. An analysis of the world distribution of published records of the Monstrilloida revealed that the Northeast Atlantic is the best studied region (45% of all records), followed by the Northwestern Atlantic (17%); the least surveyed areas include regions of the southern hemisphere (less than 3%). The Northeast Atlantic region harbors the highest number of known species (32 nominal species), followed by the Caribbean Sea/Gulf of Mexico (24), the Mediterranean/Black Sea (19), Indonesia-Malaysia-Philippines region (17), Japanese waters (17), and the Brazil-Argentina area (16). Other than these generalized patterns, little can be concluded concerning the biogeography of the group. Many species records are doubtful or improbable, and purportedly cosmopolitan nominal species are being revealed as species complexes yet to be studied. PMID:21853055

  11. Pesticides Drive Stochastic Changes in the Chemoreception and Neurotransmission System of Marine Ectoparasites.

    PubMed

    Núñez-Acuña, Gustavo; Boltaña, Sebastián; Gallardo-Escárate, Cristian

    2016-01-01

    Scientific efforts to elucidate the mechanisms of chemical communication between organisms in marine environments are increasing. This study applied novel molecular technology to outline the effects of two xenobiotic drugs, deltamethrin (DM) and azamethiphos (AZA), on the neurotransmission system of the copepod ectoparasite Caligus rogercresseyi. Transcriptome sequencing and bioinformatics analyses were conducted to evaluate treatment effects on the glutamatergic synaptic pathway of the parasite, which is closely related to chemoreception and neurotransmission. After drug treatment with DM or AZA, stochastic mRNA expression patterns of glutamatergic synapse pathway components were observed. Both DM and AZA promoted a down-regulation of the glutamate-ammonia ligase, and DM activated a metabotropic glutamate receptor that is a suggested inhibitor of neurotransmission. Furthermore, the delousing drugs drove complex rearrangements in the distribution of mapped reads for specific metabotropic glutamate receptor domains. This study introduces a novel methodological approach that produces high-quality results from transcriptomic data. Using this approach, DM and AZA were found to alter the expression of numerous mRNAs tightly linked to the glutamatergic signaling pathway. These data suggest possible new targets for xenobiotic drugs that play key roles in the delousing effects of antiparasitics in sea lice. PMID:27258252

  12. Pesticides Drive Stochastic Changes in the Chemoreception and Neurotransmission System of Marine Ectoparasites

    PubMed Central

    Núñez-Acuña, Gustavo; Boltaña, Sebastián; Gallardo-Escárate, Cristian

    2016-01-01

    Scientific efforts to elucidate the mechanisms of chemical communication between organisms in marine environments are increasing. This study applied novel molecular technology to outline the effects of two xenobiotic drugs, deltamethrin (DM) and azamethiphos (AZA), on the neurotransmission system of the copepod ectoparasite Caligus rogercresseyi. Transcriptome sequencing and bioinformatics analyses were conducted to evaluate treatment effects on the glutamatergic synaptic pathway of the parasite, which is closely related to chemoreception and neurotransmission. After drug treatment with DM or AZA, stochastic mRNA expression patterns of glutamatergic synapse pathway components were observed. Both DM and AZA promoted a down-regulation of the glutamate-ammonia ligase, and DM activated a metabotropic glutamate receptor that is a suggested inhibitor of neurotransmission. Furthermore, the delousing drugs drove complex rearrangements in the distribution of mapped reads for specific metabotropic glutamate receptor domains. This study introduces a novel methodological approach that produces high-quality results from transcriptomic data. Using this approach, DM and AZA were found to alter the expression of numerous mRNAs tightly linked to the glutamatergic signaling pathway. These data suggest possible new targets for xenobiotic drugs that play key roles in the delousing effects of antiparasitics in sea lice. PMID:27258252

  13. Distant water sailors: parasitic Copepoda of the open ocean

    NASA Astrophysics Data System (ADS)

    Jones, J. B.

    1998-06-01

    Copepods represent one of the largest groups of ectoparasites of marine fish. They have been extensively studied in coastal waters where they have become major pests in aquaculture. However, there is very little information on the ecology of parasitic copepods of fishes in the open ocean. It is now recognised that oceanographic conditions determine the distribution and abundance of oceanic fish. The same conditions also influence the survival of both the individual parasitic copepod and its species.

  14. Historical biogeography of the neotropical Diaptomidae (Crustacea: Copepoda)

    PubMed Central

    2014-01-01

    Introduction Diaptomid copepods are prevalent throughout continental waters of the Neotropics, yet little is known about their biogeography. In this study we investigate the main biogeographical patterns among the neotropical freshwater diaptomid copepods using Parsimony Analysis of Endemicity (PAE) based on species records within ecoregions. In addition, we assess potential environmental correlates and limits for species richness. Results PAE was efficient in identifying general areas of endemism. Moreover, only ecoregion area showed a significant correlation with diaptomid species richness, although climatic factors were shown to provide possible upper limits to the species richness in a given ecoregion. Conclusion The main patterns of endemism in neotropical freshwater diaptomid copepods are highly congruent with other freshwater taxa, suggesting a strong historical signal in determining the distribution of the family in the Neotropics. PMID:25057279

  15. The Australian Monstrilloida (Crustacea: Copepoda) II. Cymbasoma Thompson, 1888.

    PubMed

    Suárez-Morales, Eduardo; Mckinnon, A David

    2016-01-01

    Monstrilloid copepods collected during the past two decades from zooplankton surveys in reef and coastal areas of Australia were analyzed. A first contribution included the taxonomic analysis of three genera of the Monstrilloida, Monstrillopsis Sars, 1921, Maemonstrilla Grygier & Ohtsuka, 2008, and the newly described Australomonstrillopsis Suárez-Morales & McKinnon, 2014. In this document a taxonomic analysis of the species belonging to the genus Cymbasoma Thompson, 1888 is provided. A total of 28 species were found, most of them being undescribed. Seventeen species were described based on females only and eight on male specimens while three species were described from both sexes. Males of Australian species of Cymbasoma are distinguished by details of the genital complex, body size and proportions, ornamentation and processes of the cephalic region, number of caudal setae, and the characteristic structure or ornamentation of the genital lappets. Two main groups of males were distinguished on the basis of the number of caudal setae (3 or 4). As for the females, 20 of the 25 new species of Cymbasoma have fifth legs with an unarmed inner lobe and three setae on the outer lobe; one of these species (C. jinigudira sp. nov.) belongs to the C. longispinosum species-group (sensu Üstün et al. 2014). Another group, consisting of five species, has only two setae on the outer (exopodal) lobe. There were no Australian species of Cymbasoma with a single lobe. A species group, named after C. agoense, is proposed to include species sharing a globose body and a female fifth leg with a large endopodal lobe and an outer (exopodal) lobe with two setae. The females of the new species of Cymbasoma from Australia can be distinguished from their known congeners by unique combinations of characters including the type of body ornamentation, body size and shape, antennule armature and proportions, the presence of distinctive features of the legs 1-4, the presence/absence of processes on the genital compound somite, and the presence/absence of a constriction of the anal somite. We report the occurrence of two previously described species, C. agoense Sekiguchi, 1982 from Japan and C. bali Desai & Krishnaswamy, 1962 from India in Australian waters. Considering the addition of the 25 new species here described, the number of nominal species of the genus is now 66. A key to the Australian species of Cymbasoma (males and females) and a map showing their occurrence in Australia are also provided. PMID:27394608

  16. Phylogeny of the Paracalanidae Giesbrecht, 1888 (Crustacea: Copepoda: Calanoida).

    PubMed

    Cornils, Astrid; Blanco-Bercial, Leocadio

    2013-12-01

    The Paracalanidae are ecologically-important marine planktonic copepods that occur in the epipelagic zone in temperate and tropical waters. They are often the dominant taxon - in terms of biomass and abundance - in continental shelf regions. As primary consumers, they form a vital link in the pelagic food web between primary producers and higher trophic levels. Despite the ecological importance of the taxon, evolutionary and systematic relationships within the family remain largely unknown. A multigene phylogeny including 24 species, including representatives for all seven genera, was determined based on two nuclear genes, small-subunit (18S) ribosomal RNA and Histone 3 (H3) and one mitochondrial gene, cytochrome c oxidase subunit I (COI). The molecular phylogeny was well supported by Maximum likelihood and Bayesian inference analysis; all genera were found to be monophyletic, except for Paracalanus, which was separated into two distinct clades: the Paracalanus aculeatus group and Paracalanus parvus group. The molecular phylogeny also confirmed previous findings that Mecynocera and Calocalanus are genera of the family Paracalanidae. For comparison, a morphological phylogeny was created for 35 paracalanid species based on 54 morphological characters derived from published descriptions. The morphological phylogeny did not resolve all genera as monophyletic and bootstrap support was not strong. Molecular and morphological phylogenies were not congruent in the positioning of Bestiolina and the Paracalanus species groups, possibly due to the lack of sufficient phylogenetically-informative morphological characters. PMID:23831457

  17. Risk assessment for parasites in cultures of Diplodus puntazzo (Sparidae) in the Western Mediterranean: prospects of cross infection with Sparus aurata.

    PubMed

    Sánchez-García, Neus; Raga, Juan Antonio; Montero, Francisco E

    2014-08-29

    The sharpsnout seabream Diplodus puntazzo is of interest in Mediterranean fish farming. Disease is an important problem because parasites can spread quickly in culture conditions and fish often develop high parasite burdens. Here we assess the risk that documented parasites pose to the sustainability of D. puntazzo farming. This study specifically considers metazoan and protist parasites recorded from wild and farmed D. puntazzo in scientific literature. Risk assessment studies involve the identification, characterization and qualitative quantification of the risk in question (parasitoses in this case) and the probability of establishment. We considered the parasite species which may be difficult to manage as a priority for research into potential management strategies. Those parasites which could be transmitted from cultures of gilthead seabream (Sparus aurata) were also included in this study. Four groups of parasites represented a risk to D. puntazzo farming, ranging from moderate to high: Ciliophora, Myxozoa, Monogenea and Copepoda. Three parasite species were considered high risk to D. puntazzo cultures: Amyloodinium sp., Cryptocaryon sp. and Enteromyxum leei. These species were responsible for high mortalities in cultures of these and other fish species. In addition Sparicotyle chrysophrii, Caligus ligusticus and Gnathia vorax entail a moderate risk to D. puntazzo Mediterranean farms. No important episodes have been related to caligids and isopods in Mediterranean sparids, nevertheless they should be properly managed to prevent future problems. PMID:24893693

  18. Early life history of Neocalanus plumchrus (Calanoida: Copepoda) in the western subarctic Pacific

    NASA Astrophysics Data System (ADS)

    Fujioka, Hidefumi A.; Machida, Ryuji J.; Tsuda, Atsushi

    2015-09-01

    The life history of copepods during nauplius stages has rarely been studied, because of difficulties in identification. This study describes the development of an identification method that uses integrated microscopic analysis and real-time PCR based method to distinguish and estimate the abundance of pelagic calanoida nauplii, Neocalanus plumchrus, and to determine their phenology and ontogenetic vertical migration (OVM) in the Oyashio region. The overall approach of identification included: classify field samples of calanoida nauplii into six developmental stages by microscopic analysis, determining the Cq values from each representative nauplii by real-time PCR using specie specific probe and primer pair for N. plumchrus, calculating the |ΔCq| values from the standard curve, distinguish N. plumchrus nauplii by the criterion of |ΔCq| ⩽ 2, and calculate the abundance of N. plumchrus nauplii using results obtained from microscopic analysis and real-time PCR. Validation of the method showed that our real-time PCR based approach could identify N. plumchrus nauplii in field samples with as low as 9% of underestimation, the effect of which is negligibly low on the investigation. The results showed that early nauplius stages (first and second nauplius stages: N1 and N2, respectively) were observed during the period from October 2009 to May 2010. Spawning females were also observed during the same period, and these results confirm that the spawning period of N. plumchrus is at least 8 months long. N3 was the most dominant stage in October 2009, January, and March 2010, the distribution depth of N3 was between 500 m and 2000 m in October 2009 and their vertical distribution range was extended until April 2010. Late stages (N4-N6) were rarely observed during the period from October 2009 to March 2010, and they occurred abundantly from the surface layer (0-20 m) in April 2010. The dominance of N3 from October to March and the sudden occurrence of later stages in April indicate arrested development of N3 in the mesopelagic layer.

  19. A new species of Metacyclops from a hyporheic habitat in North Vietnam (Crustacea, Copepoda, Cyclopidae)

    PubMed Central

    Kołaczyński, Andrzej

    2015-01-01

    Abstract A new species of Metacyclops is described from hyporheic waters and small rock depression with leaf litter in North Vietnam, the Tam Đao Mountains). Metacyclops amicitiae sp. n. can be distinguished from its congeners by the unique combination of the following characters: 12-segmented antennule, distal segment of P4 endopodite bearing a single apical spine, and the surface ornamentation of the intercoxal sclerites in P1–P4 (pilose on the distal margin of P1-P4 and spinulose on the caudal surface of P4). The latter character separates the new Metacyclops from its closest relative, Metacyclops ryukyuensis, known only from the Ryukyu Islands (Ishigaki). The genus Metacyclops with the new species described herein is also for the first time recorded from Vietnam. An identification key is provided to the south and east Asian species of the genus. PMID:26445932

  20. Morphological and molecular affinities of two East Asian species of Stenhelia (Crustacea, Copepoda, Harpacticoida).

    PubMed

    Karanovic, Tomislav; Kim, Kichoon; Lee, Wonchoel

    2014-01-01

    Definition of monophyletic supraspecific units in the harpacticoid subfamily Stenheliinae Brady, 1880 has been considered problematic and hindered by the lack of molecular or morphology based phylogenies, as well as by incomplete original descriptions of many species. Presence of a modified seta on the fifth leg endopod has been suggested recently as a synapomorphy of eight species comprising the redefined genus Stenhelia Boeck, 1865, although its presence was not known in S. pubescens Chislenko, 1978. We redescribe this species in detail here, based on our freshly collected topotypes from the Russian Far East. The other species redescribed in this paper was collected from the southern coast of South Korea and identified as the Chinese S. taiae Mu & Huys, 2002, which represents its second record ever and the first one in Korea. A fragment of the mtCOI gene was successfully PCR-amplified from two specimens of each species, which represents the first molecular data for this genus, and from additional 19 specimens belonging to six different species of other stenheliins from Korea and Russia. Reconstructed phylogenies confirm previously postulated monophyly of Stenhelia and polyphyly of the closely related genus Delavalia Brady, 1869. Average pairwise maximum likelihood distances between S. pubescens and S. taiae are only slightly above 10%, suggesting a very close relationship despite numerous newly discovered micro-morphological differences and despite macro-morphological similarities being probable plesiomorphies. PMID:24899857

  1. Harpacticoida (crustacea: copepoda) from the California continental shelf. Final report, September 1990-October 1995

    SciTech Connect

    Montagna, P.A.; Burgess, R.; Fiers, F.

    1995-10-01

    Specimens of new Harpacticoida species were obtained during the California Outer Continental Shelf (OCS), Phase II, Monitoring Program (CAMP) between November 1986 and May 1989. The CAMP project was a multidisciplinary study to detect and evaluate the long-term biological impacts of continental shelf oil drilling and production. The study was centered around a proposed platform site named Julius, which was never put into service. Samples were collected in the Santa Maria Basin on a regional scale (10-20 km). Harpacticoids are the second most abundant meiofaunal taxa in the Santa Maria Basin. Harpacticoids have been intensively studied in the Atlantic OCS. However, Pacific studies are limited to collections made in shallow water. There are a great number of undescribed species in the CAMP samples taken from the Santa Maria Basin. The present study is rather limited in scope and only touches on some of the dominate species found. It contains full taxonomic descriptions of six species, a pictorial key of 18 dominant species, and drawings of 42 other unknown species.

  2. A comparative analysis of the Harpacticoida (Copepoda) faunas from the northern and southern seas of Russia

    NASA Astrophysics Data System (ADS)

    Chertoprud, E. S.; Garlitska, L. A.

    2007-12-01

    Based on extensive voluminous literary data, a comparison of the Harpacticoida faunas of the Black Sea; the Sea of Azov; and the Caspian, Baltic, Barents, White, Kara, Laptev, and East Siberian seas, as well as of the Spitsbergen and Franz Josef Land areas, was performed. The degree of community and specificity of the faunas of different regions was estimated and the general patterns of the latitudinal variability in the species compositions were revealed. It is shown that the Harpacticoida faunas of geographically separated areas and even those isolated from each other such as those of the Black Sea, the Sea of Azov, and the Caspian Sea are rather similar; an hypothesis is put forward that this is caused by the common history of the seas’ formation. In contrast, the faunas of the Arctic seas (Barents, White, Kara, Laptev, and East Siberian), whose water areas are closely connected, are considerably different, being related to their different temperature conditions.

  3. Influence of three bacteria strains on the population dynamics of Tisbe holothuriae (Copepoda, Harpacticoida)

    NASA Astrophysics Data System (ADS)

    Guérin, J.-P.; Rieper-Kirchner, M.

    1991-12-01

    The influence of three bacteria strains (Helgo 21, NCMB 308 and NCMB 13) on the life cycle of Tisbe holothuriae Humes 1957 was investigated under constant experimental conditions (19 20°C and 38‰ S). For each of the first six experiments, females (F1), whose life history was followed, were obtained from a common mother (F0). Experiment no 7 was carried out with adult females (F2) obtained during exp. 4. Females were bred in 50-ml dishes and transferred to a fresh container as soon as they produced a new egg-sac. Offspring (F2: exp. 1 6; F3: exp. 7) from successive egg-layings were counted as soon as they moulted into adults. Larval mortality was estimated by enumeration of the adults issuing from a known number of nauplii that had been fed different bacteria strains. Some difficulties arose in obtaining adults with NCMB 13: it appeared to be necessary to provide this first generation with a small quantity of TetraMin (commercial fish food) in order to initiate reproduction and obtain a second generation. However, in exp. 4, F2 adult females fed NCMB 13 became ovigerous and fertile without needing TetraMin. This result is interpreted as denoting an indispensable period of adaptation to the diet, which probably requires important changes at the enzymatic level. One experiment was carried out with Helgo 21; another one with NCMB 308; two with NCMB 13 (with a unique additional meal of TetraMin to allow reproduction), two with NCMB 13 during larval development, then only tetraMin during adult stage, and one with NCMB 13 alone (with females issued from exp. 4). Data obtained regarding longevity, duration of reproduction period, number of egg-sacs and number of adult descendants show an important variability between bacteria strains. Lower results were almost always obtained with Helgo 21 and NCMB 308. An interesting result lies in the maximum number of egg-sacs: low with Helgo 21 and NCMB 308 (5), but very ample with NCMB 13 (11 in one experiment). In experiment 7, carried out with animals bearing a large coefficient of inbreeding (0.375), the results concerning the maximum number of egg-sacs are good (10) as are the mean number of descendants per female (294: the highest number of the seven experiments). These results indicate that genetic factors involved in the reduction of descendants in ageing laboratory cultures can be suppressed to a certain extent by nutritional factors. The poor results obtained with Helgo 21 and NCMB 308 alone must be considered with caution: after a period of adaptation with an alimentary complement, these strains could perhaps permit an interesting production of copepods.

  4. The status of Limnocalanus macrurus (Copepoda: Calanoida: Centropagidae) in Lake Erie

    USGS Publications Warehouse

    Kane, Douglas D.; Gannon, John E.; Culver, David A.

    2004-01-01

    The calanoid copepod Limnocalanus macrurus showed large declines in abundance and a narrowing of spatial distribution with the onset of cultural eutrophication and increases in rainbow smelt (Osmerus mordax) abundances in Lake Erie in the mid 20th century. Since 1995, however, Limnocalanus macrurus appears to have repopulated in western Lake Erie to levels of abundance that have not been observed since the late 1930s. We hypothesize that phosphorus abatement and the subsequent decrease in low dissolved oxygen events have assisted this resurgence. However, Limnocalanus macrurusabundances have not increased in the central and eastern basins, even though water quality has improved there too. High densities of rainbow smelt and associated smelt predation pressure in the central and eastern basins may be responsible for the low numbers in these basins.

  5. A new species of Metacyclops Kiefer, 1927 (Copepoda, Cyclopidae, Cyclopinae) from the Chihuahuan desert, northern Mexico

    PubMed Central

    Mercado-Salas, Nancy F.; Suárez-Morales, Eduardo; Maeda-Martínez, Alejandro M.; Silva-Briano, Marcelo

    2013-01-01

    Abstract A new species of the freshwater cyclopoid copepod genus Metacyclops Kiefer, 1927 is described from a single pond in northern Mexico, within the binational area known as the Chihuahuan Desert. This species belongs to a group of Metacyclops species with a 3443 spine formula of swimming legs. It is morphologically similar to Metacyclops lusitanus Lindberg, 1961 but differs from this and other congeners by having a unique combination of characters, including a caudal rami length/width proportion of 3.5–3.8, a innermost terminal seta slightly longer than the outermost terminal seta, intercoxal sclerites of legs 1-4 naked, a strong apical spine of the second endopodal segment of leg 1 and one row of 6-8 small spinules at the insertion of this spine. The finding of this species represents also the first record of the genus in Mexico and the third in North America, where only two other species, Metacyclops gracilis (Lilljeborg, 1853)and Metacyclops cushae Reid, 1991 have been hitherto reported. This is also the first continental record of a species of Metacyclops from an arid environment in the Americas. This species appears to be endemic to the Chihuahuan Desert, thus emphasizing the high endemicity of this area. PMID:23794845

  6. Morphological and molecular affinities of two East Asian species of Stenhelia (Crustacea, Copepoda, Harpacticoida)

    PubMed Central

    Karanovic, Tomislav; Kim, Kichoon; Lee, Wonchoel

    2014-01-01

    Abstract Definition of monophyletic supraspecific units in the harpacticoid subfamily Stenheliinae Brady, 1880 has been considered problematic and hindered by the lack of molecular or morphology based phylogenies, as well as by incomplete original descriptions of many species. Presence of a modified seta on the fifth leg endopod has been suggested recently as a synapomorphy of eight species comprising the redefined genus Stenhelia Boeck, 1865, although its presence was not known in S. pubescens Chislenko, 1978. We redescribe this species in detail here, based on our freshly collected topotypes from the Russian Far East. The other species redescribed in this paper was collected from the southern coast of South Korea and identified as the Chinese S. taiae Mu & Huys, 2002, which represents its second record ever and the first one in Korea. A fragment of the mtCOI gene was successfully PCR-amplified from two specimens of each species, which represents the first molecular data for this genus, and from additional 19 specimens belonging to six different species of other stenheliins from Korea and Russia. Reconstructed phylogenies confirm previously postulated monophyly of Stenhelia and polyphyly of the closely related genus Delavalia Brady, 1869. Average pairwise maximum likelihood distances between S. pubescens and S. taiae are only slightly above 10%, suggesting a very close relationship despite numerous newly discovered micro-morphological differences and despite macro-morphological similarities being probable plesiomorphies. PMID:24899857

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

    NASA Astrophysics Data System (ADS)

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

    2016-02-01

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

  8. A new genus (Copepoda, Harpacticoida, Laophontidae) from Jeju Island of Korea

    PubMed Central

    Back, Jinwook; Lee, Wonchoel

    2014-01-01

    Abstract A survey on the harpacticoid copepods from an intertidal zone in Hyeopjae sandy beach, Jeju Island, Korea, resulted in the discovery of an unusual laophontid, Jejulaophonte hyeopjaeensis sp. n., which cannot be placed in any extant genus within the family. To accommodate the species, a new genus of the family Laophontidae T. Scott, 1905 is proposed and fully described here. The new species is closely related to the lineage of the five primitive genera, Carraroenia McCormack, 2006, Coullia Hamond, 1973, Hemilaophonte Jakubisiak 1933, Psammoplatypus Lee & Huys, 1999, and Robustunguis Fiers, 1992 (the CCHPR-lineage) by the reduced P2 endopod, ovate shape of the female P5 exopod and sexual dimorphism in the P3 endopod. However, it displays discrepancies from the species of the CCHPR-lineage in the presence of an inner seta on P3 and P4 exp-2, four setae on P4 enp-2, and an inner seta on P3 and P4 enp-2 in the female. Furthermore, no other species within the family Laophontidae has three setae on P2 exp-3 and a seta on P2 enp-2 at the same time. The new species has sexual dimorphism in the antennule, genital segmentation and the legs from P2 to P5. The terminal seta on the second endopodal segment of P2 in the male is longer than that in the female. The endopod of P3 is 3-segmented and displays a short inner apophysis on the second segment in the male. The outer setae on the exopod of P3 and P4 are distinctly thicker and stronger in the male than in the female. Mitochondrial cytochrome oxidase subunit I (mtCOI) sequencing of the new species has been realized in order to be used in future phylogenetic analysis. PMID:25349513

  9. A new species of Metacyclops from a hyporheic habitat in North Vietnam (Crustacea, Copepoda, Cyclopidae).

    PubMed

    Kołaczyński, Andrzej

    2015-01-01

    A new species of Metacyclops is described from hyporheic waters and small rock depression with leaf litter in North Vietnam, the Tam Đao Mountains). Metacyclops amicitiae sp. n. can be distinguished from its congeners by the unique combination of the following characters: 12-segmented antennule, distal segment of P4 endopodite bearing a single apical spine, and the surface ornamentation of the intercoxal sclerites in P1-P4 (pilose on the distal margin of P1-P4 and spinulose on the caudal surface of P4). The latter character separates the new Metacyclops from its closest relative, Metacyclops ryukyuensis, known only from the Ryukyu Islands (Ishigaki). The genus Metacyclops with the new species described herein is also for the first time recorded from Vietnam. An identification key is provided to the south and east Asian species of the genus. PMID:26445932

  10. Euryphorus suarezi n. sp. (Copepoda: Caligidae) parasitic on an elasmobranch from the Gulf of Mexico.

    PubMed

    Morales-Serna, Francisco Neptalí; Rodríguez-Santiago, María Amparo; Gómez, Samuel

    2016-01-01

    Currently, the caligid genus Euryphorus Milne Edwards, 1840 contains two valid species. A new species, Euryphorus suarezi, is described based on adult females and males collected from the spotted eagle ray Aetobatus narinari (Euphrasen) (Elasmobranchii: Myliobatidae), captured off Campeche and Tabasco, Mexico (southern coast of the Gulf of Mexico). The new species is mainly distinguished from its congeners by the absence of dorsal plates, the presence of postantennal process, bifurcated maxillule, maxilliped with slender corpus, and leg 4 with 3-segmented endopod. Leg 6 is conspicuous in the male. Additional differences are described. This is the first record of a species of Euryphorus from an elasmobranch host, which may provide insight into the evolutionary relationships within the Caligidae. PMID:26739291

  11. On the uncertainty beneath the name Oithona similis Claus, 1866 (Copepoda, Cyclopoida).

    PubMed

    Cepeda, Georgina D; Sabatini, Marina E; Scioscia, Cristina L; Ramírez, Fernando C; Viñas, María D

    2016-01-01

    The marine cyclopoid Oithona similis sensu lato Claus, 1866, is considered to be one of the most abundant and ubiquitous copepods in the world. However, its minimal original diagnosis and the unclear connection with its (subjective) senior synonym Oithona helgolandica Claus, 1863, may have caused frequent misidentification of the species. Consequently, it seems possible that several closely related but distinct forms are being named Oithona similis or Oithona helgolandica without explicit and accurate discrimination. Here the current situation concerning the correct assignment of the two species is revised, the morphological characters commonly used to identify and distinguish each species are summarized, and the nomenclatural implications of indiscriminately using these names in current taxonomic and ecological practice is considered. It is not intended to upset a long-accepted name in its accustomed meaning but certainly the opposite. "In pursuit of the maximum stability compatible with taxonomic freedom" (International Commission of Zoological Nomenclature), we consider that reassessment of the diagnostic characters of Oithona similis sensu stricto cannot be postponed much longer. While a consensus on taxonomy and nomenclatural matters can be attained, we strongly recommend specifically reporting the authority upon which the identification of either Oithona similis s.l. or Oithona helgolandica s.l. has been accomplished. PMID:26865812

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

    NASA Astrophysics Data System (ADS)

    Almén, A.-K.; Vehmaa, A.; Brutemark, A.; Bach, L.; Lischka, S.; Stuhr, A.; Furuhagen, S.; Paul, A.; Bermúdez, R.; Riebesell, U.; Engström-Öst, J.

    2015-10-01

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

  13. Genetic variability of the Metridia lucens complex (Copepoda) in the Southern Ocean

    NASA Astrophysics Data System (ADS)

    Stupnikova, Alexandra N.; Molodtsova, Tina N.; Mugue, Nikolay S.; Neretina, Tatyana V.

    2013-12-01

    Analysis of the fragment of the mtDNA gene СО1 has revealed two genetically distinct groups of the Metridia lucens complex in the South part of the Atlantic. While the intragroup polymorphism was less than 1%, the intergroup difference was about 9.5%. These two groups may be considered as representing two cryptic species within the M. lucens complex: M. lucens North and M. lucens South. These forms are found mainly to the North and to the South of the South Polar Front. The results are confirmed by an analysis of the nuclear rDNA ITS1-5.8S-ITS2 fragment. No hybrids between the two forms were detected. M. lucens North inhabits the waters > 4 °C that allow us to discuss the temperature as putative limiting factor for the distribution.

  14. Macrocyclops albidus (Copepoda: cyclopidae) for the Biocontrol of Aedes albopictus and Culex pipiens in Italy.

    PubMed

    Veronesi, Rodolfo; Carrieri, Marco; Maccagnani, Bettina; Maini, Stefano; Bellini, Romeo

    2015-03-01

    The aim of our study was to assess the potential of Macrocyclops albidus as a biological control agent against the 1st and 2nd instars of Culex pipiens and Aedes albopictus. Under laboratory conditions of prey saturation (50 1st instars/copepod), an average of 58.98% of Cx. pipiens and 54.99% of Ae. albopictus larvae were killed by 1 copepod in 24 h. Trials run in big drums containing 200 liters of water showed that the M. albidus population, inoculated in April, efficiently controlled the mosquito population for the entire season. The predator was particularly effective against Ae. albopictus, as only 2 larvae of this species were found in the treated drums, compared to 814 larvae in untreated control drums throughout the study period. No difference was observed in the control efficacy between the 2 initial densities of copepods used. The reduction in Ae. albopictus density in the drums with 100 and 500 M. albidus with respect to the control drums was 99.90 ± 0.35% and 100.0 ± 0.0%, respectively. For Cx. pipiens, the reduction in density was 88.69 ± 13.51% and 84.65% in drums inoculated with 100 and 500 copepods, respectively. Macrocyclops albidus populations survived through the winter and continued to keep the mosquito population under control during the 2008 season. The M. albidus population developed very well both in drums placed in sunny and shaded areas and proved to be tolerant to both high (summer) and low (winter) temperatures. Trials performed on M. albidus survival in catch basins showed that after a few weeks, the copepod population dramatically decreased and subsequently disappeared. The main problem for copepod survival in catch basins seemed to be the low oxygen tension and accumulation of toxic substances, rather than copepods being flushed out in heavy rainfall episodes. During the period when copepods were present, they maintained the mosquito population under control; their partial disappearance from the catch basins, however, would require more recolonization intervention to maintain mosquito control during the season. PMID:25843174

  15. A new species of Peltidium Philippi, 1839 (Crustacea, Copepoda, Harpacticoida) from the Pacific coast of Mexico

    PubMed Central

    Suárez-Morales, Eduardo; Jarquín-González, Jani

    2013-01-01

    Abstract During the analysis of phytal meiobenthic samples collected from a rocky-sandy beach in the state of Nayarit, in the Mexican Pacific, several specimens of harpacticoid copepods were obtained and taxonomically examined. These specimens were found to represent an undescribed species of the peltidiid genus Peltidium Philippi, 1839. The new species, Peltidium nayarit sp. n. is described herein. It resembles Peltidium nichollsi Geddes and Peltidium lerneri Geddes from Bahamas but also the widespread Peltidium speciosum Thompson & Scott and Peltidium purpureum Philippi. The new species from the Mexican Pacific differs from its known congeners by its possession of a unique combination of characters, including a modified pectinate seta on the antennary exopod, three terminal setae on the second endopodal segment of leg 1, third exopodal segment of leg 1 with three elements, inner terminal claw twice as long as outer claw, female fifth leg with 5 exopodal setae, exopodal setae I-III stout, spinulose and seta IV being as long as seta V. This is the second species of the family known to be distributed in the Eastern Tropical Pacific and in Mexico. Pending additional data, the distribution of this species appears to be restricted to this area of the Mexican Pacific. PMID:24003319

  16. A new protocol for ecotoxicological assessment of seawater using nauplii of Tisbe biminiensis (Copepoda:Harpacticoida).

    PubMed

    Lavorante, Beatriz R B O; Oliveira, Deloar D; Costa, Bruno V M; Souza-Santos, Lília P

    2013-09-01

    Copepods are largely used in toxicity tests. The nauplii of these organisms are more sensitive to contaminants than the adult stage. The aim of the present study was to test a protocol for the use of nauplii of the copepod Tisbe biminiensis in the ecotoxicological assessment of seawater. The sensitivity of these organisms to zinc sulphate (ZnSO4·7H2O) was also determined. The following conditions were established for the protocol based on the best development of nauplii to copepodites: 72-h duration, the microalga Chaetocerus gracilis at 2.5×10(5)cellsmL(-1) as feed and incubation temperature of 28°C. In the zinc sulphate sensitivity tests, EC50-72 h and LC50/72 h were 3.25±0.59 mg L(-1) and 3.46±0.72 mg L(-1), respectively, as estimated by the final number of copepodites and total number of live animals in relation to the mean number of inoculated nauplii. The estimated NOEC was 2.0 mg L(-1). The test developed is fast and not labour intensive. T. biminiensis nauplii exhibit sensitivity to zinc sulphate similar to that of other species of copepods employed in water toxicity tests, demonstrating the usefulness of these organisms in ecotoxicological studies involving samples of environmental seawater. PMID:23769123

  17. Redescription of Bradya typica Boeck, 1873 (Copepoda: Harpacticoida: Ectinosomatidae) with the first description of the male

    NASA Astrophysics Data System (ADS)

    Seifried, Sybille; Veit-Köhler, Gritta

    2010-03-01

    Bradya typica Boeck, 1873 is described from samples collected in the course of a colonisation experiment in Kongsfjorden, Spitsbergen (2003-2005). The male of B. typica, the type-species of the genus is described for the first time. B. typica can be distinguished from its congeners by its caudal rami (1.4 times longer than wide) and by its P5 (exopod longer than wide, inner terminal seta of exopod longest, inner seta of baseoendopod longer than outer one and surface seta rigid and curved). Variability within the species is rather small as only the length of some setae is slightly different. B. cladiofera Lang, 1965, B. congenera Sars, 1920, B. minutiseta Soyer, 1973 and B. pugiochaeta Arlt, 1983 are closely related to B. typica. Some details of the morphology, such as the body ornamentation and the longer hair-like pinnules on the spines of the swimming legs, are very difficult to observe even with maximum magnification. With certainty, B. typica is distributed near the Norwegian coast (Oslo Fjord to Trondheim Fjord), the Swedish coast (Skagerak to Öresund), around Spitsbergen and around the polar islands north of Grinnelland (Canadian Arctic Archipelago near Baffin Bay). Records of B. typica from the Kara Sea (near Novaya Zemlya), near Franz Joseph Land, Iceland, Greenland, the British Isles and from deep waters of the North Sea have to be confirmed.

  18. Mating behaviour of Pseudodiaptomus annandalei (Copepoda Calanoida) with emphasis on rejection rate

    NASA Astrophysics Data System (ADS)

    Dur, G.; Souissi, S.; Schmitt, F. G.; Hwang, J. S.; Cheng, S. H.

    2009-04-01

    Mating behaviour has important consequences at both individual and population levels. Reproductive fitness is of paramount importance to sustain the success of planktonic copepod populations in aquatic environments. The calanoid copepod Pseudodiaptomus annandalei has one of the largest geographical ranges for Indo-Pacific Pseudodiaptomidae. It is also of great importance in fish culture pounds south of Taiwan. However, the mating behavior of this species has never been studied. Mating and predatory behaviour are conceptually the same. In both cases, the encounter and the interactions occur between two individuals with opposite characteristics: predator-prey for predation; male-female for mating. The mating behaviour may be defined as a sequence of encounter, pursuit, capture and copulation. Several observed behaviour suggest that both sexes asses and choose among available mates before the copulation. Pre-copulatory mate choice in copepods may manifest as mate guarding where males attached to CV females until their final moult, complicated pre-copulatory dance and escaping. During our preliminary observations, we notice that P. annandalei females escape by shaking, often violently, the males that have caught them. Consequently for such a species the act of mating may be visualized as a chain of six events (i.e. search, encounter, pursuit, capture, selective dance, copulation).Within this chain, encounter, capture and copulation are conditional events depending on the successful conclusion of their preceding events in the chain. In this study, we examined the different step in the mating behaviour of the scarcely studied sub-tropical copepod, Pseudodiaptomus annandalei, collected from the Danshuei estuary (North Taiwan). The individuals were observed using a 3D optical system to obtain simultaneous front and side views. Males, when placed in the water where females had previously swum in, showed significant increase of their swimming velocities. Additionally, their swimming trajectories are more convoluted, indicating that males explore larger volume of fluid to increase the probability to encounter a female. The mate finding behaviour appears to depend not only on chemical signal but also on hydromechanical signals. Some males exhibited shifts of direction when females were passing by. When male intercepted a chemical trail left by a female, they initiate tracking behaviour racing up the trail with increasing speed. Males pursued pheromone trails up to 24 sec old and 10 mm long. Most studies of mating behaviour have focused on detection and sometimes pursuit, but few have addressed the other components of successful mating, namely, capture and copulation. Moreover, mate choice issue has largely been ignored in regards to pelagic copepods. Consequently very few are known about the plasticity of rejection rates as a function of mate encounter rates. The second aim of this experiment is to describe the process used by female to select their mate and to fill the gap in the quantification of mating success. Once caught by a male, P. annandalei's females entered in intensive dance which sometimes lead to shake off the males suggesting a female mate choice. The three-dimensional trajectories described by the couple during this event were characterized by fast loops and intense jumps. Individual's access to mates may be affected by operational sex ratios, causing strong variation in mating success. We finally manipulated adult sex ratios of the brackish copepod P. annandalei, to examine the influence of population sex ratio on mating success of P. annandalei in a final set of experiment concluding the investigation. It should be notice that, to our knowledge, it the first quantification ever done before. The plasticity of rejection rate was therefore investigated as a function of sex-ratio and mate encounter rate. The encounter rate reached maximum value for balanced proportion of male and female and decreased as the sex ratio unbalanced. Higher value of success was nevertheless observed for a pro-male sex-ratio.

  19. Two new species of benthopelagic Stephos (Copepoda, Calanoida, Stephidae) from Korea

    PubMed Central

    Moon, Seong Yong; Youn, Seok-Hyun; Venmathi Maran, B. A.

    2015-01-01

    Abstract Two new species of benthopelagic copepods of the genus Stephos T. Scott, 1892, belonging to the family Stephidae G.O. Sars, 1902, are described based on specimens collected in the stagnant water flooding the burrows excavated by ocypodid crabs in two intertidal mud-flats, and from near-bottom shallow waters in Korea, respectively. They can be easily diagnosed based on the ornamentation of both the female genital double-somite and genital operculum; the morphology of the distal segment of the male right P5; the presence/absence of a tiny pointed process on the distomedial angle of second segment of female P5; and the condition (seta or spine) of the lateral armature element on the distal segment of female fifth legs, among other features. This is one of the few cases reported of calanoid copepods living as commensals of other invertebrates, and raises to six the number of members of the genus reported from Asia. This is also the first record of the family Stephidae in Korea. PMID:25901119

  20. Effects of seven diets on the population dynamics of laboratory cultured Tisbe holothuriae Humes (Copepoda, Harpacticoida)

    NASA Astrophysics Data System (ADS)

    Miliou, H.; Moraïtou-Apostolopoulou, M.

    1991-09-01

    The harpacticoid copepod Tisbe holothuriae was collected from Saronicos Gulf (Greece) and reared under constant laboratory conditions. In order to study the effects of food on the population dynamics, seven diets were tested: the seaweed Ulva; five artificial compound feeds: the liquid Fryfood® (Waterlife), a powder of Mytilus, yeast, soya and Spirulina, respectively; and a mixed diet consisting of Ulva and Fryfood. The life cycle parameters (mortality, sex ratio, generation time, offspring production) were measured, and the demographic variables [mean generation time (T), net reproductive rate (Ro), and intrinsic rate of natural increase (rm)] were determined. As to their efficiency regarding population dynamics, the diets ranked as follows: (1) Ulva+Fryfood, (2), Ulva, (3) Fryfood, (4) Mytilus, (5) soya, (6) yeast, and (7) Spirulina. In this order they cause a progressive increase of both larval mortality and generation time, a progressive decrease of sex ratio, number of offspring per egg sac, number of egg sacs per female and, consequently, of Ro and rm. The observed differences between diets were most pronounced with respect to offspring production. Of the compound diets, those containing animal extracts were more efficient than those containing vegetable materials. Ulva plays an important role in the nutrition of T. holothuriae, favouring offspring production as well as larval survival, development and pigmentation. Ulva in combination with Fryfood led to a greater copepodid survival and offspring production. This mixed diet proved to be the most favourable for rearing the Greek population of t. holothuriae, resulting in an efficient intrinsic rate of natural increase (rm=0.304) of the population.

  1. Littoral microcrustacean (Cladocera and Copepoda) indicators of acidification in Canadian Shield lakes.

    PubMed

    Walseng, Bjørn; Yan, Norman D; Schartau, Ann Kristin

    2003-04-01

    We identify littoral microcrustacean indicators of acidification in 2 surveys of Canadian Shield lakes conducted 10 years apart. We found a total of 90 cladoceran and copepod species with richness increasing severalfold from acidic to nonacidic lakes. The fauna of the nonacidic lakes differed between the surveys. The 1987 survey employed activity traps, and caught more littoral taxa than the more recent, net-haul-based survey. Similar faunas were identified in the acidified lakes in both surveys, and several good indicator species were identified. For example, Acanthocycops vernalis was restricted to lakes with pH < 6. Sinobosmina sp. was very common but only in lakes with pH > 4.8. Tropocyclops extensus, Mesocyclops edax, and Sida crystallina were commonly found but only at pH > 5, and Chydorus faviformis only at pH > 5.9. These indicators showed promise in gauging the early stages of recovery from acidification in 3 lakes that were included in both surveys. PMID:12839197

  2. Marine Flora and Fauna of the Northeastern United States. Copepoda: Lernaeopodidae and Sphyriidae.

    ERIC Educational Resources Information Center

    Ho, Ju-Shey

    This report is part of a sub-series to aid biology students, biologists, biological oceanographers, and informed laymen in the identification and study of marine flora and fauna of the Northeastern United States. Contents of this report include: (1) Introduction; (2) Glossary; (3) Key to the marine lernaeopodoid copepods of the Northeastern United…

  3. Euryphorus brachypterus (Copepoda: Caligidae) on wild pacific bluefin tuna from the Tsugaru Strait, northern Japan.

    PubMed

    Kanaiwa, Minoru; Yamamoto, Yuki; Hiraoka, Yuko; Kato, Minoru; Ishimura, Gakushi; Katahira, Hirotaka

    2016-06-01

    Parasitic copepods infecting large scombrid fishes have been known for a long time because their hosts are economically important. Most studies, however, have focused on their morphology or their infection status in aquaculture from pathological viewpoints, and very few quantitative surveys have been conducted under conditions in the wild. This study therefore investigated the prevalence of Euryphorus brachypterus (Caligidae) in wild Pacific bluefin tuna (PBF). Results of sampling from August to September 2014 at the western area of the Tsugaru Strait, Japan showed that 13.2% of the PBF individuals (n=1978) were infected with this copepod. The prevalence of infections was highest in larger fish but varied among landing dates, which were classified into three clusters and in all smaller fish, the prevalence of infections was zero. This suggests that E. brachypterus mainly uses the larger PBF, which becomes sources of further infections in other seas, and that at least two host populations with different infection statuses at the strait. PMID:26861209

  4. Feeding behaviour of adult Centropages hamatus (Copepoda, Calanoida): Functional response and selective feeding experiments

    NASA Astrophysics Data System (ADS)

    Saage, Andrea; Vadstein, Olav; Sommer, Ulrich

    2009-06-01

    The feeding behaviour of adults of the marine calanoid copepod Centropages hamatus was studied in laboratory experiments with ciliates and phytoplankton as food sources. The ingestion rate of algal (flagellates, diatoms) and ciliate prey (oligotrichs) as a function of prey concentration could be described by a Holling type III functional response, with close to zero ingestion rates at concentrations below 5 µg C l - 1 . In general, ingestion of ciliates was higher than ingestion of algae, and maximum feeding rates by adult males reached were half the feeding rates of adult females at prey concentrations exceeding 50 µg C l - 1 . When diatoms and ciliates were offered together C. hamatus (both sexes) fed exclusively on ciliates as long as they contributed with more than 5% to the mixture. This indicates the capability of active prey selection and switching between suspension feeding and ambush predation. Therefore, the feeding behaviour of adult C. hamatus can be characterised as omnivorous with a preference for larger motile prey. This implies a trophic level above two, if there is a sufficient abundance of protozoan food available.

  5. Population dynamics of Tisbe holothuriae (Copepoda; Harpacticoida) in exploited mass cultures

    NASA Astrophysics Data System (ADS)

    Gaudy, R.; Guerin, J. P.

    Three cultures of Tisbe holothuriae in 101 tanks were harvested each 7 or 10 to 12 days at a rate of 50%. The most frequently harvested culture showed the highest yield. At lower exploitation rates a higher rate of sea water renewal resulted in a higher production. In the cultures, variations in sex ratio, ovigerous rate, and number of eggs per sac contributed to a stabilization of the egg production. More frequent harvesting favoured the ovigerous rate and a higher renewal rate of the medium resulted in more eggs per sac. The growth rate of the population was estimated from calculated values for birth rate and death rate, and this estimate was compared with the observed growth rate. The quality of the sea water medium in mass cultures was investigated and discussed in its effects on population dynamics.

  6. Reproduction of Pseudocalanus newmani (Copepoda: Calanoida) is deleteriously affected by diatom blooms A field study

    NASA Astrophysics Data System (ADS)

    Halsband-Lenk, Claudia; Pierson, James J.; Leising, Andrew W.

    2005-11-01

    Copepod secondary production has traditionally been linked to the spring diatom bloom in temperate and high latitudes, but laboratory studies have recently challenged this view and have shown either reduced fecundity or viability of offspring when copepods were fed high concentrations of - mostly unialgal - diatoms. However, field evidence that diatoms affect copepod reproduction is still scarce. We analyzed the reproductive response of a common, small calanoid copepod of the boreal Pacific, Pseudocalanus newmani, to spring diatom blooms in Dabob Bay, a semi-enclosed fjord of Puget Sound, Washington, USA. Abundance patterns, egg production rates, egg hatching success, and naupliar viability of the egg-carrying copepod were examined between February and early May in the years 2002-2004. The population underwent strong variations in abundance during both years, with high abundance of all stages from February to mid-March, but dramatically decreasing individual numbers later in spring. A recovery to higher numbers occurred in July. While egg production rates were independent of chlorophyll concentrations, the reproductive success of P. newmani was negatively affected by certain phytoplankton bloom conditions. Hatching success and - more markedly - naupliar survival were reduced following peaks of Thalassiosira species that were producing anti-mitotic aldehydes, but were high during periods when phytoplankton blooms were more diverse or dominated by other prey taxa including diatoms. As a consequence, recruitment of the naupliar population was considerably affected by the Thalassiosira blooms. This study shows for the first time that the so-called diatom effect operates in nature when all prerequisites - (1) high concentration of aldehyde producers, (2) few prey alternatives, and (3) feeding of copepods on these algae - are given. However, the effect was transient in Dabob Bay and may be so in other pelagic ecosystems. It remains to discern the potential sources of mortality, such as toxicity, malnutrition, predation, and/or advection, that may have caused the strong decline of the Pseudocalanus population during April.

  7. A new genus of Cletopsyllidae (Copepoda, Harpacticoida) from Gulf of Mexico

    PubMed Central

    Bang, Hyun Woo; Baguley, Jeffrey G.; Moon, Heejin

    2014-01-01

    Abstract A new genus and new species of the family Cletopsyllidae Huys & Willems, 1989 from deep-sea sediment in the Gulf of Mexico, are reported and fully described and illustrated. The new genus Pentacletopsyllus (type species: P. montagni sp. n.) can be distinguished from the four known genera of the family by antennule segmentation, length ratio of first and second endopodal segments of P1, and armature pattern on P5 exopod. It also differs from its sister genera by the rostrum being bifid at the tip, third segment of the female antennule having a smooth posterior margin, the baseoendopod of P5 with biarticulate outer setophore bearing basal seta, and female caudal rami without lobate expansion. A revised key to species of the family Cletopsyllidae Huys & Willems, 1989 is provided. PMID:24715778

  8. Four new Schizopera (Copepoda, Harpacticoida) from marine interstitial habitats in Korea.

    PubMed

    Karanovic, Tomislav; Cho, Joo-Lae

    2016-01-01

    With more than 100 valid species, the predominantly marine genus Schizopera Sars, 1905 has a near global distribution. The genus is also relatively successful in invading estuarine and freshwater ecosystems. In Korea only two widely distributed estuarine species have been recorded previously: S. clandestina (Klie, 1924) and S. neglecta Akatova, 1935. Four rare new species discovered in marine interstitial habitats are reported herein. Schizopera daejinensis sp. nov. and S. yeonghaensis sp. nov. are described after a single female and one specimen of each sex respectively. These two species were found living simpatrically in Daejin beach, near Yeong Hae city, on the East Coast of Korea. The minute S. gangneungensis sp. nov. is described after three females from a beach in Gangneung city, also on the East Coast of Korea. Schizopera sindoensis sp. nov. is described after one female and five males from a tiny beach on Jeju Island, on the South Coast of Korea. Our detailed survey of Korean beaches and the absence of any of these species in other localities suggest them to be either short range endemics or anthropogenic relics. We discuss the need for further study and protection of these neglected habitats, and the role they might play in harbouring disproportionate levels of diversity. A variety of phenotypic features for comparative descriptions of the four new species were used, including all cuticular organs (sensilla and pores) on the somites. These minute and underutilized structures provide as much resolution on the species level as traditionally used characters do, with an added bonus of an almost complete lack of sexual dimorphism. This might provide useful directions for future pairing of opposite sexes in these and other copepods, especially in cases of sympatric congeners or missing sexes. PMID:27395109

  9. Hematological alterations in Astyanax altiparanae (Characidade) caused by Lernaea cyprinacea (Copepoda: Lernaeidae).

    PubMed

    Corrêa, Lincoln L; Tavares-Dias, Marcos; Ceccarelli, Paulo S; Adriano, Edson A

    2016-06-15

    This study describes the hematological alterations in Astyanax altiparanae associated with infestation with Lernaea cyprinacea. The study was carried out in a lagoon of the Mogi-Guaçu River, in the municipality of Pirassununga, in the state of São Paulo, Brazil. Of 46 fish examined, 45.6% had their integument infested by L. cyprinacea, with a mean intensity of 4.9 parasites per fish and a mean abundance of 2.2, giving a total of 139 recovered crustaceans. The abundance of L. cyprinacea correlated positively with the length and weight of the hosts, and the intensity of infestation was higher in female hosts. Macroscopic observation of lesions associated with the parasite showed a severe inflammatory reaction around the site of attachment of L. cyprinacea, associated with a lower relative condition factor and blood parameters. The hematocrit, number of red blood cells and thrombocytes were higher in non-parasitized than in parasitized fish. However, the hemoglobin concentration, hematimetric indices and the number of white blood cells were not influenced by infestation. PMID:27304872

  10. Evidence of cryptic and pseudocryptic speciation in the Paracalanus parvus species complex (Crustacea, Copepoda, Calanoida)

    PubMed Central

    2014-01-01

    Introduction Many marine planktonic crustaceans such as copepods have been considered as widespread organisms. However, the growing evidence for cryptic and pseudo-cryptic speciation has emphasized the need of re-evaluating the status of copepod species complexes in molecular and morphological studies to get a clearer picture about pelagic marine species as evolutionary units and their distributions. This study analyses the molecular diversity of the ecologically important Paracalanus parvus species complex. Its seven currently recognized species are abundant and also often dominant in marine coastal regions worldwide from temperate to tropical oceans. Results COI and Cytochrome b sequences of 160 specimens of the Paracalanus parvus complex from all oceans were obtained. Furthermore, 42 COI sequences from GenBank were added for the genetic analyses. Thirteen distinct molecular operational taxonomic units (MOTU) and two single sequences were revealed with cladistic analyses (Maximum Likelihood, Bayesian Inference), of which seven were identical with results from species delimitation methods (barcode gaps, ABDG, GMYC, Rosenberg’s P(AB)). In total, 10 to 12 putative species were detected and could be placed in three categories: (1) temperate geographically isolated, (2) warm-temperate to tropical wider spread and (3) circumglobal warm-water species. Conclusions The present study provides evidence of cryptic or pseudocryptic speciation in the Paracalanus parvus complex. One major insight is that the species Paracalanus parvus s.s. is not panmictic, but may be restricted in its distribution to the northeastern Atlantic. PMID:24581044

  11. Reciprocal transfer study of north temperate and subtropical populations of Mesocyclops edax (Copepoda: Cyclopoida)

    NASA Astrophysics Data System (ADS)

    Wyngaard, Grace A.

    1998-06-01

    The examination of local and geographically based life history variation is one approach to examine how different selective forces may have molded life histories. Michigan and Florida populations of the warm-water copepod Mesocyclops edax exhibit genetically based differences in maturation time, body size, clutch size, and egg volume as determined by common rearing experiments in the laboratory. Florida females mature more rapidly, yet achieve larger body sizes and clutch sizes relative to Michigan females. In an effort to relate the different life histories to the specific environments, in the present study I reared both populations in enclosures suspended in the Michigan and Florida lakes. Under the high temperature and food conditions of the Florida lake, the Michigan population retained the relatively longer female maturation times and smaller clutch sizes, providing further evidence that the Michigan population is genetically constrained to divert relatively less energy to reproduction than growth compared to the Florida population. The higher survivorship of the Florida population at temperatures above 31°C relative to the Michigan population suggests the Florida animals are better adapted to extreme, high temperatures. Under the low food conditions of the Michigan lake relative to the Florida lake, the Michigan females matured more rapidly and achieved the same body size as the Florida population, but the Michigan clutches were still smaller and had larger eggs. The relative performances of the Michigan and Florida females in the in situ enclosures provided additional support for the conclusion that the Michigan population is adapted to low food conditions and the Florida population to high food and high temperature conditions.

  12. A new species of Moraria (Crustacea: Copepoda: Harpacticoida) from the Laurentian Great Lakes

    USGS Publications Warehouse

    Reid, Janet W.; Lesko, Lynn T.

    2003-01-01

    Moraria hudsoni n. sp. is described from Trails End Bay in Lake Michigan and Prentiss Bay in Lake Huron, Michigan, USA. The new species differs from its congeners in chaetotaxy, body ornamentation, and other characters. We review published records of members of Moraria from North and Central America; no species is known from South America. Species of this genus have been found in the mountains of southern Mexico, Guatemala, and Honduras, but none of these has been validly described. In North America, eight species have been recorded from Alaska, Canada, and the conterminous USA as far south as North Carolina. We report new geographical records of M. affinis from Virginia, and of both M. cristata and M. virginiana from Maryland and Virginia. We provide a tabular key to aid in identification of the named species of Moraria in North America.

  13. Infestation and Pathological Alterations by Ergasilus sarsi (Copepoda) on the Tanganyika Killifish from Africa

    PubMed Central

    Kilian, Esmari; Avenant-Oldewage, Annemariè

    2013-01-01

    A total of 204 Ergasilus sarsi, a copepod, were collected from Tanganyika Killifish Lamprichthys tanganicanus in Lake Tanganyika during March 2010. The prevalence was 86.40%, the mean intensity was 7.56, and the mean abundance was 6.38. Only 27 of the fish were infested, and the highest infestation on one fish was 29. Proliferation of mucus cells and lamellar fusion occurred. Haemorrhage due to blood vessel compression was noted. This is the first record of E. sarsi from Tanganyika Killifish. This study is also the first to provide a description of the pathological alterations caused by E. sarsi. PMID:24341764

  14. Instar growth and molt increments in Lepeophtheirus salmonis (Copepoda: Caligidae) chalimus larvae.

    PubMed

    Eichner, Christiane; Hamre, Lars Are; Nilsen, Frank

    2015-02-01

    The salmon louse (Lepeophtheirus salmonis) is an ectoparasitic copepod causing severe problems to the fish farming industry and to wild salmonids. Morphologically, all stages in the life cycle of L. salmonis have been described in detail based on successive samples from host populations. However, the rate of development differs between males and females as well as between individuals. It has therefore been difficult to observe development within stages, and this has led to a longstanding misinterpretation of the number of chalimus stages. Here samples of chalimi obtained for 12 consecutive days were observed daily in incubators. Chalimus 1 was able to molt in incubators only when fully grown and close to molting, whereas chalimus 2 was able to molt at about 60% of total instar growth. Total length instar growth was about 35% in both chalimus 1 and chalimus 2 and about equal among males and females; the cephalothorax increased by about 12% and the posterior body by about 80%. Instar growth was probably the main factor that led to the former belief that L. salmonis had four chalimus stages. Relative total length increase at molting was at the same order of magnitude as instar growth, but total length of females increased significantly more than that of males at molting. Consequently, a sexual size dimorphism was established upon molting to chalimus 2 and males were about 10% smaller than females. While growth by molting was mainly caused by cephalothorax increase, instar growth was mainly due to increase of the posterior body. The cephalothorax/total length ratio decreased from beginning to end of the instar phase suggesting that it may be used as an instar age marker. Male and female chalimus 2 can almost uniquely be identified by cephalothorax length. Chalimus 1 lasted between 5 and 6 days for males and between 6 and 7 days for females at 10°C. Chalimus 2 males lasted between 6 and 7 days and females between 7 and 8 days. PMID:25451218

  15. Developmental stages and fecundity of Lepeophtheirus simplex (Copepoda: Caligidae) parasitic on bullseye puffer fish (Sphoeroides annulatus).

    PubMed

    Neptali Morales-Serna, Francisco; Rivas-Salas, Ana Ines; Gomez, Samuel; Fajer-Avila, Emma Josefina

    2015-01-01

    Lepeophtheirus simplex Ho, Gómez et Fajer-Avila, 2001 is a parasite of Sphoeroides annulatus (Jenyns), an economically important fish species, with potential for aquaculture, in northwestern Mexico. The goal of this study was to describe the developmental stages under experimental conditions and seasonal fecundity of this parasite on wild fish. There are two naupliar, one copepodid, two chalimus and two pre-adult stages preceding the adult of L. simplex. The results support previous findings, which point out that the life cycle of the caligid copepods includes only six post-naupliar stages. The generation time from egg extrusion to adult for L. simplex was approximately 10 days at 22 °C. The body length of the ovigerous females ranged between 2.2 and 4.1 mm, and its fecundity between 12 and 36 eggs per string. Fecundity was negatively correlated with the egg size and positively correlated with the egg string length. Our data did not reveal significant differences in fecundity among sampling months, but ovigerous females were significantly larger in March (when water temperature was 22 °C) than in June and July (when water temperature was 30 °C). To some extent, our fecundity results contrast with those found in species of sea lice from higher latitudes. Undoubtedly, biological information on different species of sea lice from different environmental conditions will enhance our understanding of their infection strategies and will be valuable, given the increasing interest in marine fish farming in Mexico. PMID:25960548

  16. Mating behaviour of Pseudodiaptomus annandalei (Copepoda, Calanoida) in calm and turbulent waters

    NASA Astrophysics Data System (ADS)

    Lee, C. H.; Dahms, H. U.; Cheng, S. H.; Souissi, S.; Schmitt, F. G.; Kumar, R.; Hwang, J. S.

    2009-04-01

    Behavioral observations of male copepods reveal that they commonly follow female copepods' footprints to find their mates. Female generated environmental signals are primarily of hydromechanical or chemical quality. The intensity of hydromechanical or chemical signals is affected by the hydrodynamic conditions which in turn may modulate a copepod's ability to sense signals in their search for mates in the aquatic environment. We studied the patterns and efficiency of the copepod Pseudodiaptomus annandalei to mate at still and turbulent water conditions during day and night and in different shape and volume experimental containers. The ability of courtship in P. annandalei was recorded to be a negative function of hydromechanical disturbances as the successful mating was observed in still water only. Under turbulent condition males were not able to track a female properly. We records in the present study that both, sequential and simultaneous taxi mechanisms are used by the male P. annandalei to follow either hydromechanic or chemical signals. Our results further reveal that males follow a signal more accurately characterized as a trail. The ability of P. annandalei males to track a three-dimensional trail appears unique, and possibly depends on the persistence of fluid-borne hydromechanical or chemical signals created in low Reynolds number hydrodynamic regimes. Keywords: Mating behavior, Turbulence, Flow, Hydrodynamic conditions

  17. On the uncertainty beneath the name Oithona similis Claus, 1866 (Copepoda, Cyclopoida)

    PubMed Central

    Cepeda, Georgina D.; Sabatini, Marina E.; Scioscia, Cristina L.; Ramírez, Fernando C.; Viñas, María D.

    2016-01-01

    Abstract The marine cyclopoid Oithona similis sensu lato Claus, 1866, is considered to be one of the most abundant and ubiquitous copepods in the world. However, its minimal original diagnosis and the unclear connection with its (subjective) senior synonym Oithona helgolandica Claus, 1863, may have caused frequent misidentification of the species. Consequently, it seems possible that several closely related but distinct forms are being named Oithona similis or Oithona helgolandica without explicit and accurate discrimination. Here the current situation concerning the correct assignment of the two species is revised, the morphological characters commonly used to identify and distinguish each species are summarized, and the nomenclatural implications of indiscriminately using these names in current taxonomic and ecological practice is considered. It is not intended to upset a long-accepted name in its accustomed meaning but certainly the opposite. “In pursuit of the maximum stability compatible with taxonomic freedom” (International Commission of Zoological Nomenclature), we consider that reassessment of the diagnostic characters of Oithona similis sensu stricto cannot be postponed much longer. While a consensus on taxonomy and nomenclatural matters can be attained, we strongly recommend specifically reporting the authority upon which the identification of either Oithona similis s.l. or Oithona helgolandica s.l. has been accomplished. PMID:26865812

  18. Selective predation by bluegill sunfish (Lepomis macrochirus) on three species of Diaptomus (Copepoda) from subtropical Florida

    SciTech Connect

    Elmore, J.L.; Vodopich, D.S.; Hoover, J.J.

    1983-07-01

    The electivity of young bluegills (Lepomis marochirus) feeding on three species of Diaptomus was examined experimentally in aquaria. Young bluegills consumed more adult female D. floridanus than D. mississippiensis, with D. dorsalis being consumed in the smallest numbers. An experiment was conducted with a nonvisual siphon device in an attempt to separate the visibility and escape ability components of the feeding electivity. Although somewhat variable, escape ability was linearly related to body size of the copepods, with D. dorsalis being captured least often by the siphon, D. floridanus being caught an intermediate number of times, and D. mississippiensis being caught most often. Comparisons of the two experiments indicated that differences in numbers of D. dorsalis and D. floridanus eaten by bluegills were determined primarily by disparities in visibility attributable to pigmentation, whereas differences in numbers of D. dorsalis and D. mississippiensis eaten could be accounted for by their escape ability alone. Trends in numbers of D. mississippiensis and D. floridanus eaten were influenced by both their visibility, as determined by body size, and their escape ability. The finding of this study support the hypothesis that D. floridanus and D. mississippiensis could be excluded by fish predation from lakes in which D. dorsalis occurs. 21 references, 3 figures, 1 table.

  19. The Australian Monstrilloida (Crustacea: Copepoda) I. Monstrillopsis Sars, Maemonstrilla Grygier & Ohtsuka, and Australomonstrillopsis gen. nov.

    PubMed

    Suárez-Morales, Eduardo; Mckinnon, A David

    2014-01-01

    Monstrilloid copepods were collected during zooplankton surveys in reef and coastal areas of Australia. Representatives of all four genera of the Monstrilloida (Monstrilla Dana, Monstrillopsis Sars, Cymbasoma Thompson, and Maemonstrilla Grygier & Ohtsuka) were recorded. In this contribution a taxonomic analysis of specimens belonging to the latter two genera is provided, and a new genus described. The genus Monstrillopsis was represented exclusively by male specimens, on the basis of which three new species are described: Mon. hastata sp. nov., Mon. boonwurrungorum sp. nov., and Mon. nanus sp. nov. These are distinguished from each other and previously described species of this genus by details of the genital complex (or genital apparatus), body size, ornamentation of the cephalic surface, number of caudal setae, and characteristic modifications of the fifth antennular segment. All have distinctive characters not associated with sexual modifications, which will ease the task of matching females collected in future studies. Australomonstrillopsis gen. nov. is proposed to accommodate a male specimen with a unique combination of characters including massively developed caudal rami, cephalic perioral protuberances, and absence of an inner seta on the first exopodal segment of legs 1-4, among other characters. The new genus is monotypic and contains A. crassicaudata sp. nov. Three of the four new species of Maemonstrilla (Mae. ohtsukai sp. nov., Mae. hoi sp. nov., and Mae. protuberans sp. nov.) belong to the Mae. hyottoko species group, and the remaining one, Mae. crenulata sp. nov., belongs to the Mae. turgida group. Each of the new species of Maemonstrilla from Australia can be distinguished from its known congeners by a unique combination of characters including the type of body reticulation, body size, antennule and body proportions, distinctive characters of the swimming legs, details of the antennular armature, and the presence/absence of a posteroventral process on the genital compound somite. With the addition of the four new species of Monstrillopsis and the four of Maemonstrilla described herein, the number of species in these genera has increased to 13 and 11 species, respectively. In no case did congeneric species co-occur, hinting that there may be a rich species diversity yet to be discovered within the Australian Monstrilloida. PMID:24871727

  20. Mesozooplankton distribution in the Spermonde Archipelago (Indonesia, Sulawesi) with special reference to the Calanoida (Copepoda)

    NASA Astrophysics Data System (ADS)

    Cornils, Astrid; Schulz, Jan; Schmitt, Petra; Lanuru, Mahatma; Richter, Claudio; Schnack-Schiel, Sigrid B.

    2010-12-01

    In September 2005 the mesozooplankton distribution, taxonomic composition and community structure were studied on four cross-shelf and one coastal transects in the Spermonde Archipelago off Makassar (SW Sulawesi). A total of 47 higher taxonomic groups and 89 calanoid copepod species were identified. Copepods outnumbered the other mesozooplankton taxa with 29 to 69%, increasing in importance towards the offshore stations. Appendicularians ranked second (16-24%) followed at the offshore stations by chaetognaths (4.5%) and, at shelf and coastal stations by echinoderm pluteus larvae (11-15%). Within the calanoids, species of the family Paracalanidae, especially Paracalanus cf. parvus, were dominant at all stations. Other abundant families were Temoridae (6.5-17%), Acartiidae (7.2%) and Pontellidae (6.2%) at shelf and coastal stations while Clausocalanidae (8.7%) and Calanidae (6.7) were more abundant at offshore stations. To investigate the mesozooplankton distribution the 25 stations were grouped into 3 geographical zones based on their topographical and hydrographical differences (coastal, shelf and offshore zone). Some higher zooplankton taxa and about half of the calanoid species occurred only in one or two categories. In general the abundant taxa were spread throughout the Archipelago. To investigate their distribution the abundance data were subjected to a multivariate discriminant function analysis (MDFA). The results revealed that the composition of the mesozooplankton community changed from the coastal zone with a high abundance of meroplankton and neritic copepod species to an offshore community with a higher abundance of holoplanktonic organisms and oceanic copepod species.

  1. A new species of Metacyclops Kiefer, 1927 (Copepoda, Cyclopidae, Cyclopinae) from the Chihuahuan desert, northern Mexico.

    PubMed

    Mercado-Salas, Nancy F; Suárez-Morales, Eduardo; Maeda-Martínez, Alejandro M; Silva-Briano, Marcelo

    2013-01-01

    A new species of the freshwater cyclopoid copepod genus Metacyclops Kiefer, 1927 is described from a single pond in northern Mexico, within the binational area known as the Chihuahuan Desert. This species belongs to a group of Metacyclops species with a 3443 spine formula of swimming legs. It is morphologically similar to Metacyclops lusitanus Lindberg, 1961 but differs from this and other congeners by having a unique combination of characters, including a caudal rami length/width proportion of 3.5-3.8, a innermost terminal seta slightly longer than the outermost terminal seta, intercoxal sclerites of legs 1-4 naked, a strong apical spine of the second endopodal segment of leg 1 and one row of 6-8 small spinules at the insertion of this spine. The finding of this species represents also the first record of the genus in Mexico and the third in North America, where only two other species, Metacyclops gracilis (Lilljeborg, 1853)and Metacyclops cushae Reid, 1991 have been hitherto reported. This is also the first continental record of a species of Metacyclops from an arid environment in the Americas. This species appears to be endemic to the Chihuahuan Desert, thus emphasizing the high endemicity of this area. PMID:23794845

  2. The Application of DNA Barcodes for the Identification of Marine Crustaceans from the North Sea and Adjacent Regions

    PubMed Central

    Raupach, Michael J.; Barco, Andrea; Steinke, Dirk; Beermann, Jan; Laakmann, Silke; Mohrbeck, Inga; Neumann, Hermann; Kihara, Terue C.; Pointner, Karin; Radulovici, Adriana; Segelken-Voigt, Alexandra; Wesse, Christina; Knebelsberger, Thomas

    2015-01-01

    During the last years DNA barcoding has become a popular method of choice for molecular specimen identification. Here we present a comprehensive DNA barcode library of various crustacean taxa found in the North Sea, one of the most extensively studied marine regions of the world. Our data set includes 1,332 barcodes covering 205 species, including taxa of the Amphipoda, Copepoda, Decapoda, Isopoda, Thecostraca, and others. This dataset represents the most extensive DNA barcode library of the Crustacea in terms of species number to date. By using the Barcode of Life Data Systems (BOLD), unique BINs were identified for 198 (96.6%) of the analyzed species. Six species were characterized by two BINs (2.9%), and three BINs were found for the amphipod species Gammarus salinus Spooner, 1947 (0.4%). Intraspecific distances with values higher than 2.2% were revealed for 13 species (6.3%). Exceptionally high distances of up to 14.87% between two distinct but monophyletic clusters were found for the parasitic copepod Caligus elongatus Nordmann, 1832, supporting the results of previous studies that indicated the existence of an overlooked sea louse species. In contrast to these high distances, haplotype-sharing was observed for two decapod spider crab species, Macropodia parva Van Noort & Adema, 1985 and Macropodia rostrata (Linnaeus, 1761), underlining the need for a taxonomic revision of both species. Summarizing the results, our study confirms the application of DNA barcodes as highly effective identification system for the analyzed marine crustaceans of the North Sea and represents an important milestone for modern biodiversity assessment studies using barcode sequences. PMID:26417993

  3. Risk factors perceived predictive of ISA spread in Chile: applications to decision support.

    PubMed

    Gustafson, L; Antognoli, M; Lara Fica, M; Ibarra, R; Mancilla, J; Sandoval Del Valle, O; Enriquez Sais, R; Perez, A; Aguilar, D; Madrid, E; Bustos, P; Clement, A; Godoy, M G; Johnson, C; Remmenga, M

    2014-11-01

    Aquaculture is anticipated to be a critical element in future solutions to global food shortage. However, diseases can impede industry efficiency and sustainability. Consequently, diseases can and have led to dramatic re-structuring in industry or regulatory practices. The emergence of infectious salmon anemia (ISA) in Chile is one such example. As in other countries, many mitigations were instituted universally, and many incurred considerable costs as they introduced a new layer of coordination of farming activities of marine sites within common geographic areas (termed 'neighborhoods' or 'barrios'). The aggregate response led to a strong reduction in ISA incidence and impact. However, the relative value of individual mitigations is less clear, especially where response policies were universally applied and retrospective analyses are missing 'controls' (i.e., areas where a mitigation was not applied). Further, re-focusing policies around disease prevention following resolution of an outbreak is important to renew sustainable production; though, again, field data to guide this shift in purpose are often lacking. Expert panels can offer timely decision support in the absence of empirical data. We convened a panel of fish health experts to weight risk factors predictive of ISA virus (ISAV) introduction or spread between Atlantic salmon barrios in Chile. Barrios, rather than sites, were the unit of interest because many of the new mitigations operate at this level and few available studies examine their efficacy. Panelists identified barrio processing plant biosecurity, fallowing strategies, adult live fish transfers, fish and site density, smolt quality, hydrographic connection with other neighborhoods, presence of sea lice (Caligus rogercresseyi), and harvest vessel biosecurity as factors with the greatest predictive strength for ISAV virulent genotype ('HPR-deleted') occurrence. Fewer factors were considered predictive of ISAV HPR0 genotype ('HPR0') occurrence

  4. A new species of Monocheres Stock (Copepoda, Siphonostomatoida, Asterocheridae) from shallow waters off Florida, USA: an unexpected discovery

    PubMed Central

    Suárez-Morales, Eduardo

    2016-01-01

    Abstract The rare asterocherid copepod genus Monocheres, ectosymbionts of corals and sponges, contains only two species, one from Mauritius (Indian Ocean) and the other one from Brazil (western Atlantic). From the analysis of the digestive caecum contents of the benthic hesionid polychaete Hesione picta Müller, 1858, an adult female of an undescribed species of Monocheres was unexpectedly recovered; it is the third species of this rare asterocherid genus. The new species, Monocheres sergioi sp. n., has the distinctive reduction of the fifth leg as a process with a single seta. It differs from its two other congeners by several characters including the presence of an inner basipodal spine, the armature details of the third exopodal segment of leg 1, the shape of the cephalosome and pedigerous somites 3 and 4, and the ornamentation of the postero-lateral corners of the genital double-somite. The main synapomorphies include the presence of spinules along the posterior margin of the first leg coxal sclerite and the reduced, spiniform coxal seta on leg 4. The biology and feeding habits of the polychaete containing this specimen suggests that the copepod was ingested as an ectosymbiont from sponges or coral but it is also possible that it was consumed from an ophiurid echinoderm. This finding allows an expansion of the genus geographical distribution in the northwestern Atlantic. A key to the species of Monocheres is also provided. PMID:27551233

  5. Host-parasite relationships and geographic distribution of Salmincola corpulentus (Copepoda: Lernaeopodidae) on bloater (Coregonus hoyi) stocks in Lake Huron

    USGS Publications Warehouse

    Bowen, Charles A.; Stedman, Ralph M.

    1990-01-01

    Examination of the branchial cavities of 8347 adult bloaters (Coregonus hoyi) collected from seven locations in Lake Huron for parasitic copepods yielded only the lernaeopodid Salmincola corpulentus; its distribution was limited to bloaters collected in the southern two-thirds of the lake. The infections were highest off Au Sable Point and on Six Fathom Bank, where 12 and 22%, of the bloaters examined were infected, respectively. All copepods seen were sexually mature females. The dorsal anterior portion of the branchial rim was the preferred site of attachment. The prevalence of S. corpulentus increased with length of the bloaters, reaching a maximum of 40% in fish longer than 330 mm; none were seen in bloaters shorter than 182 mm. The mean intensity of S. corpulentus was unusually low (1.0–1.9) for a lernaeopodid copepod and the maximum number of copepods found on a single bloater was five. Prevalences of copepods differed significantly (P < 0.05) between bloaters collected at different geographic locations, suggesting that S. corpulentus may be of value in bloater stock determination.

  6. A new genus and species of cyclopoid (Crustacea, Copepoda, Cyclopinidae) from a coastal system in the Gulf of Mexico.

    PubMed

    Suárez-Morales, Eduardo; Almeyda-Artigas, Roberto Javier

    2015-01-01

    A new, monotypic genus of the interstitial marine cyclopoid copepod family Cyclopinidae G.O. Sars, 1913 is described from male and female specimens collected at Laguna de Términos, a large coastal lagoon system in the southern Gulf of Mexico. Mexiclopina campechana gen. et sp. n. cannot be adequately placed in any extant genus within the family. It differs from other cyclopinid genera in having a unique combination of characters including: 1) absence of modified brush-like seta on the mandibular exopod; 2) maxillule exopod with stout setal elements and brush-like setae absent; 3) basis of mandible with one seta; 4) presence of a modified seta on endopod of fourth leg; 5) fifth leg exopod unsegmented, armed with three elements in the female and five in the male; 6) intercoxal sclerite of first swimming leg with two medial spiniform processes on distal margin. The new genus is monotypic and appears to be most closely related to Cyclopina Claus, 1863 and Heptnerina Ivanenko & Defaye, 2004; the new species was compared with species of Cyclopina and it resembles Cyclopina americana Herbst, 1982 and Cyclopina caissara Lotufo, 1994. This is the second record of a species of Cyclopinidae in Mexico and the first in the Gulf of Mexico; the number of cyclopinid species recorded from the Americas is now 13. PMID:26668545

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

    NASA Astrophysics Data System (ADS)

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

    2006-08-01

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

  8. Taxonomic evaluation of eleven species of Microcyclops Claus, 1893 (Copepoda, Cyclopoida) and description of Microcyclops inarmatus sp. n. from America

    PubMed Central

    Gutiérrez-Aguirre, Martha Angélica; Cervantes-Martínez, Adrián

    2016-01-01

    Abstract Description and meristic analysis of eleven species of Microcyclops recorded in America were performed based on the examination of type specimens and fresh material. Microscopic analysis of oral appendages, such as the shape and armature of the distal coxal endite of the maxilla, the ornamentation on the caudal surface of the antenna, and the intercoxal sclerites and armament of the inner basis of all swimming appendages, were characteristics that allowed the differentiation between species. Among these species, our study confirmed the synonymy of Microcyclops diversus Kiefer, 1935 with Microcyclops ceibaensis (Marsh, 1919). The results of our observations showed that Microcyclops alius (Kiefer, 1935) is a junior synonym of Microcyclops dubitabilis Kiefer, 1934; the latter being confirmed as a valid species. Also, it is proposed that the records of Microcyclops rubellus (Lilljeborg, 1901) and Microcyclops varicans (Sars, 1863) in America should be revised as there are serious doubts about their distribution in America. The analysis suggested that Microcyclops anceps pauxensis Herbst, 1962 is distinct from Microcyclops anceps var. minor Dussart, 1984 and that both are likely different from Microcyclops anceps anceps (Richard, 1897). Finally a full morphological description of adult females of Microcyclops inarmatus sp. n. is presented. PMID:27551196

  9. Redescription of the fish parasite Lernanthropus polynemi Richiardi, 1881 (Copepoda: Siphonostomatoida) and relegation of two congeners to synonymy.

    PubMed

    Piasecki, Wojciech; Hayward, Craig J

    2002-06-01

    Lernanthropus polynemi Richiardi, 1881 is described, for the first time since its original discovery, based on the type-material found in the Museum für Naturkunde in Berlin, Germany. Morphological features of this parasite, which infects the commercially-caught fish Eleutheronema tetradactylum (Shaw), are described and illustrated, including those of the male, which is described for the first time. The types of another species from the same host, L. lappaceus Wilson, 1912, and deposited in the National Museum of Natural History in Washington DC, are also examined based on the type-specimens. The types of a third congener, L. trifoliatus Basset-Smith, 1898, also from the same host, are not available, but the original illustrations are studied. It is considered that the three nominal species described from E. tetradactylum represent a single taxon, and that L. lappaceus and L. trifoliatus be relegated to synonymy with L. polynemi. PMID:12108411

  10. A new genus and species of cyclopoid (Crustacea, Copepoda, Cyclopinidae) from a coastal system in the Gulf of Mexico

    PubMed Central

    Suárez-Morales, Eduardo; Almeyda-Artigas, Roberto Javier

    2015-01-01

    Abstract A new, monotypic genus of the interstitial marine cyclopoid copepod family Cyclopinidae G.O. Sars, 1913 is described from male and female specimens collected at Laguna de Términos, a large coastal lagoon system in the southern Gulf of Mexico. Mexiclopina campechana gen. et sp. n. cannot be adequately placed in any extant genus within the family. It differs from other cyclopinid genera in having a unique combination of characters including: 1) absence of modified brush-like seta on the mandibular exopod; 2) maxillule exopod with stout setal elements and brush-like setae absent; 3) basis of mandible with one seta; 4) presence of a modified seta on endopod of fourth leg; 5) fifth leg exopod unsegmented, armed with three elements in the female and five in the male; 6) intercoxal sclerite of first swimming leg with two medial spiniform processes on distal margin. The new genus is monotypic and appears to be most closely related to Cyclopina Claus, 1863 and Heptnerina Ivanenko & Defaye, 2004; the new species was compared with species of Cyclopina and it resembles Cyclopina americana Herbst, 1982 and Cyclopina caissara Lotufo, 1994. This is the second record of a species of Cyclopinidae in Mexico and the first in the Gulf of Mexico; the number of cyclopinid species recorded from the Americas is now 13. PMID:26668545

  11. Giselinidae fam. nov., a new monophyletic group of cyclopoid copepods (Copepoda, Crustacea) from the Atlantic deep sea

    NASA Astrophysics Data System (ADS)

    Martínez Arbizu, Pedro

    2000-12-01

    Four new species of Cyclopoida from deep-sea waters are described and placed in two new genera: Giselina gen. n. and Sensogiselina gen. n. The new genera and species belong to a new monophyletic group within the cyclopinid cyclopoids. A new name, Giselinidae, is proposed for this monophylum. The new family is characterised by the combination of the following characters: (1) tergite of leg 1 fused to cephalosome dorsally, but incompletely fused laterally, (2) absence of aesthetascs on ancestral antennulary segments XVI, XXI and XXV, (3) absence of antennary exopodal setae, (4) presence of only three spines on distal exopodal segment of leg 1, (5) absence of inner setae on first endopodal segments of legs 1-4, (6) outer terminal and distal inner elements of distal endopodal segment of leg 4 transformed into spines, (7) distal outer element of leg 5 exopod transformed into a spine, (8) leg 6 with only one seta, and (9) furcal setae I and III located on dorsal margin.

  12. Character phylogenies in Candacia and Paracandacia (Copepoda, Calanoida) and the inevitably paraphyletic nature of many nominal taxa above subspecies level

    NASA Astrophysics Data System (ADS)

    von Vaupel Klein, J. C.; Gassmann, D.

    1998-06-01

    Examination of the phylogenetic structure of the family Candaciidae shows the genus Paracandacia to comprise a strongly modified branch emerging from the clade commonly denoted as Candacia. This has been confirmed by studying selected character phylogenies. It is argued that the resulting paraphyletic nature of Candacia auct., though in a cladistic context undesirable on theoretical grounds, has to be accepted as inevitable. Recent studies on molluscs and arthropods, viz., have demonstrated that the continuous origin of paraphyletic taxa from previously monophyletic ones is nothing but a naturally occurring process, intrinsically embodied in the course of evolution.

  13. Submarine ridges do not prevent large-scale dispersal of abyssal fauna: A case study of Mesocletodes (Crustacea, Copepoda, Harpacticoida)

    NASA Astrophysics Data System (ADS)

    Menzel, Lena; George, Kai Horst; Arbizu, Pedro Martínez

    2011-08-01

    We examined the large-scale distribution of deep-sea harpacticoid copepods at the species level, in order to clarify the underlying processes of copepod dispersal. The study was based on samples collected from 12 regions and a total of 113 stations: 57 stations at depths between 1107 and 5655 m on abyssal plains in the South and North Atlantic, Southern Ocean, southern Indian Ocean, and the Pacific Ocean, and 56 stations above 900 m in the North Atlantic and eastern Mediterranean Sea. We chose the genus Mesocletodes Sars, 1909 as an ideal group to study the large-scale distribution of harpacticoid copepods in the deep oceans. Clear apomorphies and a comparatively large body size of about 1 mm allow rapid recognition of allied species in meiofauna samples. In addition, Mesocletodes represents more than 50% of the family Argestidae Por, 1986, one of the most abundant harpacticoid families in the deep sea. The geographical distributions of 793 adult females of Mesocletodes belonging to 61 species throughout the South and North Atlantic, Southern Ocean, southern Indian Ocean, Pacific Ocean, and eastern Mediterranean Sea indicated that most species are cosmopolitan. Neither the topography of the sea bottom nor long distances seem to prevent species from dispersing. Passive transport by bottom currents after resuspension is likely the propulsive factor for the dispersal of Harpacticoida, while plate tectonics and movement of individuals in the sediment may play relatively minor roles.

  14. A new species of Zosime (Copepoda: Harpacticoida: Zosimeidae) from shallow subtidal habitats in Korea, with notes on the genus.

    PubMed

    Kim, Jong Guk; Jung, Tae Won; Yoon, Seong Myeong

    2016-01-01

    Zosime destituta sp. nov. is described from shallow subtidal habitats in the southern sea of Korea. The new species is similar to Z. valida Sars, 1919, but differs from it primarily by the lack of an inner seta on the third endopodal segment of the fourth swimming leg. Based on morphological comparison of female character states, the genus Zosime can be subdivided into three provisional groups, anneae-, incrassata-, and typica-group. These groups are distinguished from each other by differences in the antennule, antennary exopod, mandibular rami, armature of swimming legs, fifth leg, and caudal rami. In addition, Zosime incrassata bathybia Bodin, 1968 is removed from its synonymy with Z. incrassata Sars, 1910 and upgraded to species level. An amended key to all known species of Zosime Boeck, 1873 is given, along with a table of all major characters. The present study is the first report of the family Zosimeidae Seifried, 2003 from Korean waters. PMID:27395718

  15. A new species of Halicyclops (Copepoda, Cyclopoida, Cyclopidae) from a lagoon system of the Caribbean coast of Colombia

    PubMed Central

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

    2014-01-01

    Abstract Plankton samples obtained from the lagoon system Laguna Navío Quebrado, in northern Colombia, yielded male and female specimens of an undescribed cyclopoid copepod of the genus Halicyclops. The new species belongs to the highly diverse and widely distributed thermophilus-complex. It closely resembles Halicyclops clarkei Herbst, 1982 from Louisiana and Halicyclops bowmani Rocha & Iliffe, 1993 from Bermuda. These species share the same armature of P1-P4EXP3, with a 3443 spine formula and the terminal antennary segment with 5 setae. However, Halicyclops gaviriai sp. n. can be separated from both Halicyclops clarkei and Halicyclops bowmani by the morphology of the anal pseudoperculum, the proportions of the fourth antennulary segment, the length of the inner basipodal spine of P1, the P1EXP/inner basipodal spine inner length ratio and the length/width ratio of the caudal rami. This is the third species of Halicyclops recorded from Colombia and the first one described from this country. With the addition of Halicyclops gaviriai sp. n., the number of species of Halicyclops known from the Neotropics increases to 19. The regional diversity of the genus is probably underestimated. PMID:25561852

  16. A new species of Ergasilus (Copepoda: Ergasilidae) from Geophagus altifrons and G. argyrostictus (Perciformes: Cichlidae) in the Brazilian Amazon.

    PubMed

    Taborda, Naraiana Lopes; Paschoal, Fabiano; Luque, José Luis

    2016-09-01

    A new species of ergasilid copepod, Ergasilus xinguensis n. sp., is described from females found on the gills of two cichlid fishes, Geophagus argyrostictus (Kullander, 1991) (type host) and G. altifrons (Heckel, 1840), from the Brazilian Amazon. The new species can be distinguished from congeners by the unique combination of the following characteristics: the cephalothorax is not inflated and is slightly constricted, the first antennulary segment bears 3 setae, maxillule with 3 unequal outer setae without minute process medially, maxilla has a large syncoxa with one seta near its basis, first and fourth legs are with a 3-segmented endopod, base of the exopod in leg 2 with a conspicuous bluntly-pointed projection and caudal ramus with two rows of curved conical spinules on ventral surface. The new species is the second member of Ergasilus von Nordmann, 1832 found on cichlids of the genus Geophagus (Heckel). PMID:27447219

  17. Identification guide to some Diaptomid species (Crustacea, Copepoda, Calanoida, Diaptomidae) of "de la Plata" River Basin (South America).

    PubMed

    Perbiche-Neves, Gilmar; Boxshall, Geoffrey Allan; Previattelli, Daniel; Nogueira, Marcos Gomes; da Rocha, Carlos Eduardo Falavigna

    2015-01-01

    An identification guide is presented for species of calanoid copepod family Diaptomidae from "de la Plata" River Basin (Argentina, Brazil, Bolivia, Paraguay and Uruguay). It was based on material collected during the summer and winter of 2010 from 43 sites across the eastern part and the lower stretches of this basin, the second largest in South America and the fourth in the world. The guide contains identification keys and species diagnoses for males and females, richly supported by scanning electronic micrographs and/or line drawings of 19 species. It also includes some general remarks on the taxonomy and phylogenetic relationships of these species. The key was adjusted to be useful for these species only, with separate keys for each sex, and is the first for females of South America. One species classified herein as incertae sedis was not included in the analysis. At least ten other species have previously been recorded in the basin but were not present in our samples. This is the first attempt to compile comprehensive taxonomic information on this group of copepods in this region, and it is expected to become a useful tool for biologists and young taxonomists interested in the crustacean biota of the Neotropical region. PMID:25931959

  18. Selective oviposition by Aedes aegypti (Diptera: culicidae) in response to Mesocyclops longisetus (Copepoda: Cyclopoidea) under laboratory and field conditions.

    PubMed

    Torres-Estrada, J L; Rodríguez, M H; Cruz-López, L; Arredondo-Jimenez, J I

    2001-03-01

    The influence of predacious Mesocyclops longisetus Thiebaud on the selection of oviposition sites by prey Aedes aegypti (L.) was studied under laboratory and field conditions. In both cases, gravid Ae. aegypti females were significantly more attracted to ovitraps containing copepods or to ovitraps with water in which copepods were held previously than to distilled water. Monoterpene and sesquiterpene compounds including 3-carene, alpha-terpinene, alpha-copaene, alpha-longipinene, alpha-cedrene, and delta-cadinene were found in hexane extracts of copepods by gas chromatography and mass spectrometry analyses. These compounds may be responsible for attracting gravid Ae. aegypti females and may increase the number of potential prey for the copepod. PMID:11296821

  19. Spatial spring distribution of the copepod Eurytemora affinis (Copepoda, Calanoida) in a restoring estuary, the Scheldt (Belgium)

    NASA Astrophysics Data System (ADS)

    Mialet, B.; Azémar, F.; Maris, T.; Sossou, C.; Ruiz, P.; Lionard, M.; Van Damme, S.; Lecerf, A.; Muylaert, K.; Toumi, N.; Meire, P.; Tackx, M.

    2010-06-01

    The spatial spring distribution of Eurytemora affinis (adults and C5) in the Scheldt estuary (Belgium) brackish and freshwater reaches was studied in between 1996 and 2007. The bulk of the E. affinis population being generally situated in the brackish water reach (salinity > 0.5); we studied which environmental factors are responsible for its recent sporadic occurrence in the freshwater estuarine reach. Using PLS analysis, it is shown that its presence upstream is limited by a sufficient oxygen concentration (>4 mg l -1) that is associated with temperature. Not only are the environmental conditions in the upstream zone important, but also the frequent presence of an O 2 minimum zone in the mid-estuary (O 2 min < 1.3 mg l -1) seems to block the movement of the downstream E. affinis population in an upstream direction. Occasionally, the bulk of the population is however situated upstream. During these periods, high E. affinis abundance was also observed in the Durme tributary. Our findings suggest the possibility to use E. affinis as an "indicator" species of water quality, but also lead us to stress the necessity to consider conditions over the entire estuary when studying restoration effects, not exclusively in the zone of interest.

  20. Histopathology of a mesoparasitic hatschekiid copepod in hospite: does Mihbaicola sakamakii (Copepoda: Siphonostomatoida: Hatschekiidae) fast within the host fish tissue?

    PubMed

    Hirose, Euichi; Uyeno, Daisuke

    2014-08-01

    Mihbaicola sakamakii is a mesoparasitic copepod that infests the branchiostegal membranes of groupers (Perciformes: Serranidae). In this study, we observed M. sakamakii within host tissue. Histologically, copepods were found enclosed inside a pouch composed of the thickened epidermis of the host, tightly encased on all sides by the host epidermal pouch wall. There were no host blood cells or other food resources in the pouch lumen. Since the host epidermis was intact and continuous, even in the vicinity of the oral region of the parasite, the copepod would not have access to the host blood in this state. However, the stomach (ampullary part of the mid gut) was filled with granular components, the majority of which were crystalloids that likely originated from fish erythrocyte hemoglobin. We supposed that the parasite drinks blood exuded from the lesion in the fish caused by copepod entry into the host tissue. Invasion of the parasite may elicit immune responses in the host, but there were no traces on the copepod of any cellular immune reactions, such as encapsulation. The array of minute protuberances on the copepod cuticle surface may be involved in avoidance of cell adhesion. After the lesion has healed, the copepod is enclosed in a tough epidermal pouch, in which it gradually digests the contents of its stomach and continues egg production. PMID:25088597

  1. A new genus of Asterocheridae (Copepoda: Siphonostomatoida) ectoassociate of the ascidian Eudistoma vannamei Millar, 1977 (Polycitoridae) from Brazil.

    PubMed

    Johnsson, Rodrigo; Bahia, Cristiano; Neves, Elizabeth

    2016-01-01

    Asterocheres Boeck, 1860 is the largest genus of the siphonostomatoid copepod family Asterocheridae, containing 63 valid species. The genus is known for its symbiotic relationships with many marine invertebrate taxa, especially sponges, cnidarians, bryozoans, and echinoderms. Recent studies have restricted the diagnosis of this genus. Consequently, many species are now considered as species inquirendae. The present paper describes a new species living externally on the tunic of Eudistoma vannamei Millar, 1977, an endemic ascidian from Brazil. As the new species does not fit Asterocheres in the strict sense, a new genus is erected to accommodate it. Setacheres gen. nov. is characterized by its possession of two distal setae on the third endopodal segment of P3, thus differing from the distal seta and spine pattern that is deemed as diagnostic of Asterocheres. A revision and comparison of Asterocheres´ species inquirendae revealed eight species sharing the same generic characteristics and were thus reallocated as members of the new genus. PMID:27395122

  2. Postembryonic stages of Nucellicola holmanae Lamb et al., 1996 (copepoda, poecilostomatoida), an endoparasite of the dog whelk Nucella lapillus (gastropoda)

    NASA Astrophysics Data System (ADS)

    Lamb, E. J.; Boxshall, G. A.; Mill, P. J.; Grahame, J.

    1998-06-01

    The external morphology of the first three larval stages of Nucellicola holmanae is described. These stages were cultured from eggs found with the adults in the viscera of dog whelks collected from Robin Hood's Bay, North Yorkshire. The nauplius develops within the whelk. It moults to a metanauplius which is released as a free-swimming stage. The metanauplius moults to a free copepodid stage which exhibits a combination of characters typical of the first, second and third copepodid stages of other poecilostomatoid copepods. The infective copepodid stage which locates and penetrates the host is visible through the integument of this free-swimming copepodid.

  3. Five new species of lichomolgid copepods associated with ascidians from Korea, with proposal of two new genera (Crustacea, Copepoda, Lichomolgidae)

    NASA Astrophysics Data System (ADS)

    Moon, Seong Yong; Kim, Il-Hoi

    2011-09-01

    Five new species of the family Lichomolgidae associated with solitary ascidians are described from the east coast of Korea. Two new genera are proposed: Protomolgus n. gen. to incorpotate Protomolgus duplex n. sp. and P. singularis n. sp., and Dontimolgus n. gen. to incorporate Dontimolgus brevicaudatus n. sp. Protomolgus n. gen. characteristically has a four-segmented female maxilliped and a bipartite mandible. Dontimolgus n. gen. possesses a large, tooth-like process on the first maxillary segment and three spines on the third exopodal segment of leg 3. Other two new species described are Lichomolgus infirmus n. sp. and L. pectinatus n. sp.

  4. A new species of Monocheres Stock (Copepoda, Siphonostomatoida, Asterocheridae) from shallow waters off Florida, USA: an unexpected discovery.

    PubMed

    Suárez-Morales, Eduardo

    2016-01-01

    The rare asterocherid copepod genus Monocheres, ectosymbionts of corals and sponges, contains only two species, one from Mauritius (Indian Ocean) and the other one from Brazil (western Atlantic). From the analysis of the digestive caecum contents of the benthic hesionid polychaete Hesione picta Müller, 1858, an adult female of an undescribed species of Monocheres was unexpectedly recovered; it is the third species of this rare asterocherid genus. The new species, Monocheres sergioi sp. n., has the distinctive reduction of the fifth leg as a process with a single seta. It differs from its two other congeners by several characters including the presence of an inner basipodal spine, the armature details of the third exopodal segment of leg 1, the shape of the cephalosome and pedigerous somites 3 and 4, and the ornamentation of the postero-lateral corners of the genital double-somite. The main synapomorphies include the presence of spinules along the posterior margin of the first leg coxal sclerite and the reduced, spiniform coxal seta on leg 4. The biology and feeding habits of the polychaete containing this specimen suggests that the copepod was ingested as an ectosymbiont from sponges or coral but it is also possible that it was consumed from an ophiurid echinoderm. This finding allows an expansion of the genus geographical distribution in the northwestern Atlantic. A key to the species of Monocheres is also provided. PMID:27551233

  5. Identification guide to some Diaptomid species (Crustacea, Copepoda, Calanoida, Diaptomidae) of “de la Plata” River Basin (South America)

    PubMed Central

    Perbiche-Neves, Gilmar; Boxshall, Geoffrey Allan; Previattelli, Daniel; Nogueira, Marcos Gomes; da Rocha, Carlos Eduardo Falavigna

    2015-01-01

    Abstract An identification guide is presented for species of calanoid copepod family Diaptomidae from “de la Plata” River Basin (Argentina, Brazil, Bolivia, Paraguay and Uruguay). It was based on material collected during the summer and winter of 2010 from 43 sites across the eastern part and the lower stretches of this basin, the second largest in South America and the fourth in the world. The guide contains identification keys and species diagnoses for males and females, richly supported by scanning electronic micrographs and/or line drawings of 19 species. It also includes some general remarks on the taxonomy and phylogenetic relationships of these species. The key was adjusted to be useful for these species only, with separate keys for each sex, and is the first for females of South America. One species classified herein as incertae sedis was not included in the analysis. At least ten other species have previously been recorded in the basin but were not present in our samples. This is the first attempt to compile comprehensive taxonomic information on this group of copepods in this region, and it is expected to become a useful tool for biologists and young taxonomists interested in the crustacean biota of the Neotropical region. PMID:25931959

  6. A new species of Prohatschekia Nunes-Ruivo, 1954 (Copepoda: Hatschekiidae) parasitic on Scorpaena elongata (Cadenat) off Algeria.

    PubMed

    Hamza, Fazia; Boxshall, Geoff; Kechemir-Issad, Nadia

    2007-06-01

    A new species of parasitic copepod, Prohatschekia mediterranea n. sp. (Siphonostomatoida: Hatschekiidae), is described from a scorpaenid fish, Scorpaena elongata, collected off Algeria. This is the seventh species of Prohatschekia Nunes-Ruivo, 1954 to be described and the first record of the genus from the Mediterranean Sea. The new species is most closely related to P. cremouxi Nunes-Ruivo, 1954, known from a congeneric host collected in Senegal. A key is provided to distinguish the new species from other members of the genus. PMID:17195930

  7. Predation on Pseudodiaptomus annandalei (Copepoda: Calanoida) by the grouper fish larvae Epinephelus coioides under different hydrodynamic conditions

    NASA Astrophysics Data System (ADS)

    Lee, C. H.; Dahms, H. U.; Cheng, S. H.; Souissi, S.; Schmitt, F. G.; Kumar, R.; Hwang, J. S.

    2009-04-01

    The copepod Pseudodiaptomus annandalei perceived larval grouper Epinephelus coioides predators and exhibited escape reactions mediated by physical and/or chemical signals but not by visual perception. Under illumination, prey capture rates were significantly higher under moderate turbulence (747 ±104, n=3) than in the controls (calm water) (597±76, n=3) (p<0.01 Mann Whitney U test). The maximum darting speed of copepod in response to fish larvae under calm water was significantly higher (one way ANOVA P<0.05, Fig. 5) than that under either turbulent or enhanced flow condition, indicating that copepopd's ability to escape from predators was higher under calm water than either under turbulent water conditions or enhanced flow. The maximum number of copepods eaten by the fish larvae increased more under slow and medium hydrodynamic conditions than that under either calm or under high speed hydrodynamic conditions. Key words: Predator-prey relation; Behavior; Hydrodynamic disturbance; Diurnal changes; Predator avoidance; Predation efficiency

  8. Genome- and transcriptome-assisted development of nuclear insertion/deletion markers for Calanus species (Copepoda: Calanoida) identification.

    PubMed

    Smolina, I; Kollias, S; Poortvliet, M; Nielsen, T G; Lindeque, P; Castellani, C; Møller, E F; Blanco-Bercial, L; Hoarau, G

    2014-09-01

    Copepods of the genus Calanus are key zooplankton species in temperate to arctic marine ecosystems. Despite their ecological importance, species identification remains challenging. Furthermore, the recent report of hybrids among Calanus species highlights the need for diagnostic nuclear markers to efficiently identify parental species and hybrids. Using next-generation sequencing analysis of both the genome and transcriptome from two sibling species, Calanus finmarchicus and Calanus glacialis, we developed a panel of 12 nuclear insertion/deletion markers. All the markers showed species-specific amplicon length. Furthermore, most of the markers were successfully amplified in other Calanus species, allowing the molecular identification of Calanus helgolandicus, Calanus hyperboreus and Calanus marshallae. PMID:24612683

  9. Two new species of the deep-sea genus Parameiropsis (Copepoda: Harpacticoida) from the eastern central Pacific.

    PubMed

    Cho, Dae Hyun; Wi, Jin Hee; Suh, Hae-Lip

    2016-01-01

    Two new species of Parameiropsis are herein described that were identified from the Korean Deep Ocean Study (KODOS) in the Clarion-Clipperton Fracture Zone, located in the eastern central Pacific. Parameiropsis kodosensis n. sp. is similar to P. magnus Itô, 1983 in two key respects: the presence of a distal seta on the syncoxa of the maxilliped, and the general features of its swimming legs. However, P. kodosensis can be differentiated from P. magnus by a higher length-to-width ratio of the caudal ramus (2.5:1 and 1:1 respectively), the setal number on the exp-3 of P1, and the exp and benp of P5 are separated in P. kodosensis, while they are fused in P. magnus. Parameiropsis tetraspinosa n. sp. resembles P. peruanus Becker, 1974 in the absence of a fused seta in the outermost spine on the endopod of antenna and the general features of the swimming legs. However, P. tetraspinosa can be distinguished from P. peruanus by a higher length-to-width ratio of the caudal ramus (3.9:1 and 2.3:1 respectively), the presence of a distal seta on the syncoxa of the maxilliped, and by its medially fused P5. In this study full descriptions and a comparison with previously described species are provided. Additionally, a key to females of Parameiropsis species is given. PMID:27395690

  10. Molecular profiles and pathogen-induced transcriptional responses of prawn B cell lymphoma-2 related ovarian killer protein (BOK).

    PubMed

    Chaurasia, Mukesh Kumar; Palanisamy, Rajesh; Harikrishnan, Ramasamy; Arasu, Mariadhas Valan; Al-Dhabi, Naif Abdullah; Arockiaraj, Jesu

    2015-08-01

    In this study, we have reported a molecular characterization of the first B cell lymphoma-2 (BCL-2) related ovarian killer protein (BOK) from freshwater prawn Macrobrachium rosenbergii (Mr). BOK is a novel pro-apoptotic protein of the BCL-2 family that entails in mediating apoptosis to remove cancer cells. A cDNA sequence of MrBOK was identified from the prawn cDNA library and its full length was obtained by internal sequencing. The coding region of MrBOK yields a polypeptide of 291 amino acids. The analysis revealed that MrBOK contains a transmembrane helix at V(261)-L(283) and a putative BCL-2 family domain at V(144)-W(245). MrBOK also possessed four putative BCL-2 homology domains including BH1, BH2, BH3 and weak BH4. The BH3 contains 21 binding sites and among them five residues are highly conserved with the aligned BOK proteins. The homology analysis showed that MrBOK shared maximum similarity with the Caligus rogercresseyi BOK A. The topology of the phylogenetic tree was classified into nine sister groups which includes BOK, BAK, BAX, BAD, BCL-2, BCL-XL, NR13 and MCL members. The BOK protein group further sub-grouped into vertebrate and invertebrate BOK, wherein MrBOK located within insect monophyletic clad of invertebrate BOK. The secondary structural analysis showed that MrBOK contains 11 α-helices (52.2%) which are connected over random coils (47.7%). The 3D structure of MrBOK showed three central helices (α6, α7 and α8) which formed the core of the protein and are flanked on one side by α1, α2 and α3, and on the other side by α4, α5 and α11. MrBOK mRNA is expressed most abundantly (P < 0.05) in ovary compared to other tissues taken for analysis. Hence ovary was selected to study the possible roles of MrBOK mRNA regulation upon bacterial (Aeromonas hydrophila and Vibrio harveyi) and viral [white spot syndrome virus (WSSV) and M. rosenbergii nodovirus] infection. During bacterial and viral infection, the highest MrBOK mRNA transcription was varied

  11. Temperature-induced changes in fatty acid dynamics of the intertidal grazer Platychelipus littoralis (Crustacea, Copepoda, Harpacticoida): Insights from a short-term feeding experiment.

    PubMed

    Werbrouck, Eva; Van Gansbeke, Dirk; Vanreusel, Ann; Mensens, Christoph; De Troch, Marleen

    2016-04-01

    Dietary lipids, and in particular the essential fatty acids (EFA), EPA (20:5ω3) and DHA (22:6ω3), guarantee the well-being of animals and are recognized for their potential bottom-up control on animal populations. They are introduced in marine ecosystems through primary producers and when grazed upon, they are consumed, incorporated or modified by first-level consumers. As the availability of EFA in the ecosystem is affected by ambient temperature, the predicted rise in ocean temperature might alter the availability of these EFA at the basis of marine food webs. Despite the FA bioconversion capacity of certain benthic copepod species, their lipid (FA) response to varying temperatures is understudied. Therefore, the temperate, intertidal copepod Platychelipus littoralis was offered a mono and mixed diatom diet at 4, 15 °C (normal range) and at 24 °C (elevated temperature) to investigate the combined effects of temperature and resource availability on its FA content and composition. P. littoralis showed a flexible thermal acclimation response. Cold exposure increased the degree of FA unsaturation and the EPA%, and induced a shift towards shorter chain FA in the copepod's membranes. Furthermore, a mixed diet reduced the impact of heat stress on the copepod's membrane FA composition. Temperature affected the trophic transfer of EPA and DHA differently. While dietary resources could fully compensate for the temperature effects on total lipid and EPA content in the copepods, no such counterweigh was observed for the DHA dynamics. Heat stress lowered the DHA concentration in copepods regardless of the resources available and this implies negative effects for higher trophic levels. PMID:27033038

  12. A new species of Dermoergasilus Ho & Do, 1982 (Copepoda: Ergasilidae) from freshwater fishes in the south-west of Western Australia.

    PubMed

    Hassan, Marina; Jones, Brian; Lymbery, Alan J

    2009-10-01

    A new species of Dermoergasilus Ho & Do, 1982 is described from freshwater fish hosts in the south west of Western Australia. D. occidentalis n. sp. differs from previously described species in the genus principally by the armature of the legs. The new species was found on the gills of the freshwater cobbler Tandanus bostocki Whitely and western minnow Galaxias occidentalis Ogilby in two different river systems. PMID:19731098

  13. The Life Cycle of the Parasitic Crustacean, Lernanthropus latis Yamaguti, 1954 (Copepoda: Lernanthropidae), on Marine-Cultured Fish, Lates calcarifer, from Setiu Wetland, Terengganu

    PubMed Central

    Abdul Khalid, Nur Qamarina; Shaharoum-Harrison, Faizah

    2014-01-01

    Parasitic crustaceans of Lernanthropus latis were isolated from the host, the seabass, Lates calcarifer, obtained from a cage culture in Setiu Wetland, Terengganu. The adult females with egg were kept alive in vials containing 20 mL of filtered seawater and incubated at 30°C. The eggs were monitored every hour and the hatching periods were recorded. Three developmental stages were observed, namely, nauplii I, nauplii II, and infective copepodid. The infective copepodids were then transferred into a tank containing 60 litres of seawater with 150 fingerlings for infection purpose. One fish was sacrificed every 24 hr to inspect the next developmental stage. As a result, six more stages were obtained within 298 hrs starting from the infection day. The stages were known as fixed copepodid I, fixed copepodid II, fixed copepodid III, fixed copepodid IV, preadult, and adult. Parasitic L. latis takes a 483 hr period to complete a life cycle. PMID:25574379

  14. Numerical and functional responses to the presence of a competitor--the case of Aggregata sp. (Apicomplexa: Aggregatidae) and Octopicola superba (Copepoda: Octopicolidae).

    PubMed

    Cavaleiro, F I; Santos, M J

    2014-02-01

    Evidence of interference competition between the eimeriorin coccidian Aggregata sp. and the octopicolid copepod Octopicola superba at the level of the gills of naturally infected Octopus vulgaris is evaluated. Numerical and functional responses are considered for analysis, and the fundamental and realized spatial niches (FSNs and RSNs) are measured as part of the study. While it was not possible to measure the FSN of Aggregata sp., the analysis of the infection levels of O. superba recorded for non-concomitantly and concomitantly infected hosts suggests that the gills and body skin constitute, respectively, the main and accessory sites of infection of the parasite. According to the evidence found, the gills function mainly as an accessory site of infection of Aggregata sp., in specimens in which the caecum and intestine are massively infected. Evidence for a negative interaction between Aggregata sp. and O. superba has been found while controlling for a potential confounding effect of host size. Furthermore, the presence of O. superba on gill lamellae appears to have been negatively affected by the presence of Aggregata sp., while this latter remained mostly undisturbed. The mean number of oocysts of Aggregata sp. in the gills was higher in spring and summer, which were also the seasons presenting the broadest RSN for O. superba. PMID:24148558

  15. Decline of Pseudodiaptomus hessei (Copepoda, Calanoida) in two water bodies located in the Senegal River hydrosystem (West Africa): Hypotheses and perspectives

    NASA Astrophysics Data System (ADS)

    Mendoza-Vera, Juana Mireya; Kâ, Samba; Cuoc, Corinne; Bouvy, Marc; Pagano, Marc

    2008-09-01

    Pseudodiaptomus hessei is a key species in many water bodies in the Senegal River hydrosystem but it became rare or completely disappeared from two ecosystems (Lake Guiers and Dakar Bango Reservoir; Senegal, West Africa) after major hydrological changes caused by human action, mainly impoundments on the river in 1985, and the opening of a new estuary mouth in 2003. Kâ et al. [Kâ, S., Pagano, M., Ba, N., Bouvy, M., Leboulanger, C., Arfi, R., Thiaw, O.T., Ndour, E.H.M., Corbin, D., Defaye, D., Cuoc, C., Kouassi, E., 2006. Zooplankton distribution related to environmental factors and phytoplankton in a shallow tropical lake (Lake Guiers, Senegal, West Africa). International Review of Hydrobiology 91(5), 389-405] put forward several hypotheses to explain the reasons for this decline: salinity and chemical changes in the water, predation by a cyclopid predator Mesocyclops ogunnus and/or the inhibiting effects of cyanobacteria and/or diatoms (allelopathy). This study assessed these hypotheses by studying the distribution of P. hessei in 13 stations (including the Dakar Bango reservoir and Lake Guiers) in relation to physical, chemical and biological (phyto- and zooplanktons) factors at each station. We produced a distribution pattern for this species in the Senegal River hydrosystem. Rank correlations and principal component analysis showed that P. hessei was not correlated with conductivity but was positively correlated with pH and alkalinity, suggesting chemical effects. The clear association with two filamentous cyanobacteria ( Cylindrospermopsis raciborskii and Anabaena sp.) did not appear to support the hypothesis of cyanobacteria inhibition but blooming conditions were never encountered during the study. Negative correlation with diatoms (especially with Fragilaria sp.) suggested that aldehyde producing diatoms had a negative effect. Negative correlations with cyclopids such as Mesocyclops supported the hypothesis of cyclopid predation to explain the decline of P. hessei. This study proposes several lines of research for future studies to test these hypotheses.

  16. On Kiefer’s American Eucyclops (Copepoda, Eucyclopinae): redescriptions and comments on the historical records of E. delachauxi, E. prionophorus, E. bondi and E. leptacanthus

    PubMed Central

    Mercado-Salas, Nancy F.; Suárez-Morales, Eduardo

    2014-01-01

    Abstract The freshwater copepod genus Eucyclops contains many supposedly cosmopolitan species whose taxonomic status is still under discussion; some of them represent species complexes. The problem is not exclusive to these widespread species; there are several American Eucyclops needing a taxonomic re-evaluation. Based on the examination of Friedrich Kiefer’s collection in Karlsruhe, Germany, the type specimens of four American species of Eucyclops (E. delachauxi (Kiefer, 1926), E. prionophorus Kiefer, 1931, E. bondi Kiefer, 1934, E. leptacanthus Kiefer, 1956) were re-examined and redescribed using upgraded descriptive standards. Kiefer’s translated descriptions and unpublished original drawings of these species are also presented. Characters like the ornamentation of the antennal basis, ornamentation of intercoxal sclerites of the swimming legs 1–4, length of basipodal seta of leg 1, ornamentation of caudal rami, the presence of aesthetascs and modified setae on the antennules in male, and the structure of the male sixth leg are compared herein to aid a more accurate separation of these American species. A revision of the American records of these species confirms that some are likely to refer to undescribed species. Overall, the diversity of the American Eucyclops appears to be underestimated and certainly deserves further study. PMID:24843261

  17. Short-term variation of nutritive and metabolic parameters in Temora longicornis females (Crustacea, Copepoda) as a response to diet shift and starvation

    NASA Astrophysics Data System (ADS)

    Kreibich, Tobias; Saborowski, Reinhard; Hagen, Wilhelm; Niehoff, Barbara

    2008-09-01

    Changes in fatty acid patterns, digestive and metabolic enzyme activities and egg production rates (EPR) were studied in the small calanoid copepod Temora longicornis. Female copepods were collected in spring 2005 off Helgoland (North Sea). In the laboratory one group of copepods was fed with the cryptophycean Rhodomonas baltica for a period of 3 days. Another group of copepods was maintained without food. According to the fatty acid patterns, animals from the field were feeding on a more detrital, animal-based and to a minor extent to a diatom-based diet. Under laboratory conditions, females rapidly accumulated fatty acids such as 18:4 (n-3), 18:3 (n-3) and 18:2 (n-6) which are specific of R. baltica. Diatom-specific fatty acids such as 16:1 (n-7) were strongly reduced. In fed animals the activities of digestive and metabolic enzymes remained constant and egg production rates were highest on day 2. Starving animals, in contrast, showed significantly reduced faecal pellet production and EPR. Proteolytic enzyme activity decreased rapidly within 24 h and remained at a low level until the end of the experiment. Citrate synthase decreased continuously as well. T. longicornis rapidly reacts to dietary changes and food depletion. It has limited energy stores and, thus, strongly depends on continuous food supply.

  18. Spatial and temporal variations in sea lice (Copepoda: Caligidae) infestations of three salmonid species farmed in net pens in southern Chile.

    PubMed

    Zagmutt-Vergara, Francisco J; Carpenter, Tim E; Farver, Thomas B; Hedrick, Ronald P

    2005-04-18

    Sea lice infestations have become a major health problem for farmed salmonids throughout the world including Chile. In southern Chile, 6 geographical areas, divided into 22 geographical zones with a total of 127 salmon farming centers and 1519 sea pens, were regularly sampled from December 1999 to April 2002. A linear mixed-effects model (LME) approach was used to describe the infestations of adult forms of sea lice on 3 salmonid species farmed in southern Chile. The variables fish species, water temperature, water salinity, fish weight, juvenile parasite count, pen shape, treatment status in previous month and the interaction of previous and current month treatments were found to be statistically significant fixed effects for the population sampled. The most susceptible species to sea lice infestation was rainbow trout Oncorhynchus mykiss, while the least susceptible species was coho salmon O. kisutch. Fishes in pens treated in the previous month with avermectins were associated with the smallest sea lice count compared to fishes in pens not treated or treated with other products. The variability in sea lice infestations in areas and zones within areas was not statistically significant when controlling for the previously mentioned fixed variables. The variability between centers, the within-pen variability, and the interaction between within-pen effect and the date of measurement were statistically significant and not explained by the fixed effects. Potential sources for this variability are discussed. We conclude that the epidemiology of sea lice infestations in farmed salmonids in southern Chile is complex and in need of further study. PMID:15918480

  19. First record and redescription of Macandrewella cochinensis Gopalakrishnan, 1973 (Copepoda, Scolecitrichidae) from the Red Sea, with notes on swarm formation

    PubMed Central

    El-Sherbiny, Mohsen M.; Al-Aidaroos, Ali M.

    2013-01-01

    Abstract During a study of the epipelagic zooplankton carried out near the fringing reef around Sharm El-Sheikh area, in the northern Red Sea, female and male specimens of the poorly known calanoid copepod Macandrewella cochinensis Gopalakrishnan, 1973 were collected. This is the first record of species occurrence in the Red Sea. Macandrewella cochinensis was previously known only from the offshore water of Cochin, south west of India. The Red Sea specimens are described in details herein to allow their comparison with the specimens from the type locality, because original description of M. cochinensis is incomplete and causes some taxonomic confusion. The most important characters that may have been overlooked in the original description are: shape of projections of the female distolateral prosomal borders, details of morphology of the asymmetrical female genital double-somite and presence of leg 5 in female. PMID:24194657

  20. Host specificity of Lepeophtheirus crassus (Wilson and Bere) (Copepoda: Caligidae) parasitic on the marlin sucker Remora osteochir (Cuvier) in the Atlantic Ocean.

    PubMed

    Ho, Ju-shey; Collete, Bruce B; Madinabeitia, Ione

    2006-10-01

    Three species of remoras--Remora brachyptera (Lowe), Remora osteochir (Cuvier), and Remora remora (Linnaeus)--were collected from 4 species of billfishes--Istiophorus platypterus (Shaw), Makaira nigricans Lacepéde, Tetrapturus albidus Poey, and Tetrapturus pfluegeri Robins and de Sylva--on board a Japanese long-liner Shoyo Maru during her cruise in 2002 across the Atlantic. However, only the marlin sucker (R. osteochir) was found to carry a parasitic copepod, Lepeophtheirus crassus (Wilson and Bere, 1936). Although 12 species of parasitic copepods have been reported from billfishes around the world ocean, none of them is L. crassus. Thus, L. crassus is considered a parasite specific to the marlin sucker. PMID:17152964

  1. A new species of Ergasilus Nordmann, 1832 (Copepoda: Cyclopoida: Ergasilidae) from Bryconops giacopinii Fernández-Yépez (Characidae) in the Vichada River Basin, Colombia.

    PubMed

    Muriel-Hoyos, Felipe; Santana-Piñeros, Ana María; Cruz-Quintana, Yanis; Suárez-Morales, Eduardo

    2015-11-01

    A new copepod species, Ergasilus curticrus n. sp. is described based on 14 female specimens collected from the gills of the characid teleost Bryconops giacopinii Fernández-Yépez, captured in the Vichada River Basin in Colombia. The new species has a unique combination of characters including: (i) 2-segmented endopods in legs 1 and 4; (ii) a semi-pinnate, falciform seta on the terminal segment of the first leg exopod; (iii) a 1-segmented fourth leg exopod; (iv) a reduced fifth leg with a single seta; and (v) a circular structure fused to a groove near the lateral margins of the second pedigerous tergite. Only two other known congeners have a 1-segmented leg 4 exopod, E. coatiarus Araujo & Varella, 1998 and E. iheringi Tidd, 1942. Among other characters, they differ from the new species by the lack of a semi-pinnate, falciform seta on the terminal exopodal segment of leg 1 and in the structure and armature of the fifth leg. The prevalence of E. curticrus n. sp. was 13.6% and its mean abundance was 0.4 specimens per host. This is the first new species of Ergasilus Nordmann, 1832 described from the Orinoco River Basin. PMID:26446546

  2. A new species of Asterocheres (Copepoda, Siphonostomatoida) with a redescription of A. complexus Stock, 1960 and A. sarsi Bandera & Conradi, 2009.

    PubMed

    Bandera, Eugenia; Conradi, Mercedes

    2014-01-01

    The present paper reviews the material of three species of Asterocheres Boeck 1859 deposited in four different Zoological European museums as part of the ongoing taxonomical revision of this genus. Asterocheres sarsi Bandera & Conradi 2009, the species described by Sars in 1915 as Ascomyzon latum (Brady 1880) and lately recognized as a distinct species by Bandera and Conradi in 2009 is fully described in this paper from material collected by Sars in Norway in 1915 and deposited in The Natural History Museum of the University of Oslo. Asterocheres complexus Stock, 1960 which has been sometimes confused with A. sarsi is redescribed from material collected by Stock in France in 1959 and deposited in the Zoological Museum of the University of Amsterdam. Furthermore, a new species, previously misidentified as A. suberitis Gieisbrecht 1897, from the Norman`s collection of The Natural History Museum of London, is described as A. eugenioi, new species. These three species, A. complexus, A. eugenioi, and A. sarsi share the general appearance of body thanks to the pointed posterolateral angle of the epimeral area of somite bearing leg 3, sometimes slightly produced into backwardly directed processes, and somite bearing leg 4 largely concealed under somite bearing leg 3. PMID:25081176

  3. Response of abyssal Copepoda Harpacticoida (Crustacea) and other meiobenthos to an artificial disturbance and its bearing on future mining for polymetallic nodules

    NASA Astrophysics Data System (ADS)

    Ahnert, Ahmed; Schriever, Gerd

    Long-term effects of an anthropogenic physical disturbance on the Harpacticoida taxocene at a deep-sea site were investigated during the course of the disturbance and recolonization (DISCOL) experiment in a manganese nodule area in the southeastern Pacific. Nineteen harpacticoid copepod families were found, contributing 9-12% to the metazoan meiofauna of the experimental area (Nematoda 72-80%). Twelve families occurred in sufficient numbers to be considered representatively sampled. Dominant are the Ameiridae (17%) followed by Ectinosomatidae, Argestidae, Tisbidae, Neobradyidae, Diosaccidae, Paranannopidae, Paramesochridae, Canthocamptidae, Cletodidae, Thalestridae and Huntemanniidae. These families are mainly distributed at random. Basic data on developmental stage composition and sex ratio of total Harpacticoida as well as vertical distribution of harpacticoid families in the sediment column are provided. Within the overall aim of the experiment, which was to assess the ecological risks of future deep-sea manganese nodule mining, we conducted multivariate community analyses based on the familial composition of the Harpacticoida assemblages immediately before and after experimental impact as well as seven years later. We were not able to detect a community response at the family level immediately after impact. An identification of the Tisbidae to species, however, revealed initial disturbance effects. After seven years we found significant differences in the assemblage composition of the directly disturbed portions of the experimental area and the secondarily disturbed areas in between, which to some extent had received blanketing from sediment plumes created during the experimental disturbance. Best discriminating families for long-term effects are the Ameiridae, Argestidae and Thalestridae. Their potential value as indicator taxa for monitoring disturbances in the deep sea is discussed, including some considerations on a cost-effective design of such monitoring programs that would include the meiofaunal Harpacticoida.

  4. A new genus and family of copepods (Crustacea: Copepoda) parasitic on polychaetes of the genus Jasmineira Langerhans, 1880 (family Sabellidae) in the northeastern Atlantic.

    PubMed

    Boxshall, Geoff A; O'Reilly, Myles; Sikorski, Andrey; Summerfield, Rebecca

    2015-01-01

    A new genus and species of copepod, Jasmineiricola mackiei n. gen. et n. sp., parasitic on at least three species of the sabellid polychaete genus Jasmineira Langerhans, 1880 is described. The adult female is mesoparasitic, living with part of its body (the endosoma) embedded within the host and part (the ectosoma) protruding through the host's body wall. The endosoma consists of a well defined head region carried anteriorly on the trunk which has paired lateral lobes housing the ovaries. The head bears a rosette-like array of eight slender lobes, which are probably derived from the mouthparts. The only limbs present on the trunk are the subchelate maxillipeds positioned immediately posterior to the head. The ectosoma consists of a posterior genito-abdominal lobe bearing paired genital apertures. The male is unknown. The new genus cannot be placed in any of the five existing families of mesoparasitic copepods on polychaete hosts and is treated as the type of a new monotypic family, the Jasmineiricolidae. The new species occurs over a depth range from 19 to 279 m, and is widely distributed from UK coastal waters to Norwegian waters inside the Arctic Circle. PMID:26624049

  5. Ameiridae Boeck and Argestidae Por revisited, with establishment of Parameiropsidae, a new family of Harpacticoida (Crustacea, Copepoda) from deep-sea sediments

    NASA Astrophysics Data System (ADS)

    Corgosinho, P. H. C.; Martínez Arbizu, P.

    2010-09-01

    Four new species of Parameiropsis are described from Angola and Guinea Basins and the Arctic Laptev Sea. The male of Parameiropsis poseidonicus sp. n. differs from that of P. neptuni sp. n. and P. senckenbergi sp. n. in antennule segmentation, length of the proximal aesthetasc, length of the outermost seta of the antennary endopod, degree of reduction of the mouthparts, relative length of the inner spine of the basis of thoracopod 1, shape of the furca and body length. The female of P. amphitriteae sp. n. differs from previously described females of other species in the smaller exopod and endpod of thoracopod 1, reduced armature of thoracopods 1-6, length of the outer setae of exopods and endopods of thoracopods 2-4, and mandible exopod weakly developed and fused to the basis. Parameiropsis is redefined by the following autapomorphies: presence of aesthetasc on 3rd segment of female antennule; antenna strong, with endopod curved upwardly, and shape of the outermost (strongly ornamented) spine; triangular labrum; elongated corpus mandibularis, gnathobasis very long; basis of mandibular palp unarmed; elongated maxillule, with long and flexible setae on praecoxal arthrite; basis of the maxilla with strongly modified claw. To discuss the phylogenetic position of Parameiropsis, we revaluated the subfamilies of Ameiridae (viz. Ameirinae and Stenocopiinae) and the family Argestidae. Anoplosomella and Malacopsyllus revealed to be not closely related to Ameiridae and are transferred to Argestidae, sharing with other members of this family the morphology of the mandible gnathobasis, armature of maxilla and armature and length of the first segment of the antennule. Argestoides prehensilis does not show any of the characters that we consider autapomorphic for Argestidae. Instead, it shows many characters in common with several Ameiridae species. Parameiropsis does not have any character that could justify its inclusion within Ameiridae or even within Podogennonta. It also cannot be included satisfactorily within Argestidae nor Exanechentera. Therefore, we here propose a new family for Parameiropsis, with unclear relationships within Harpacticoida. After these taxonomic rearrangements, Ameiridae and Argestidae are considered monophyletic based on certain maxilla characters that we consider autapomorphic for each group. A key to the identification of the known species of Parameiropsis is added at the end.

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

    PubMed

    Bamber, Roger N; Seaby, Richard M H

    2004-05-01

    Experiments have been undertaken exposing larval common shrimp (Crangon crangon) and lobster (Homarus gammarus) and adult copepods (Acartia tonsa) to the key stresses of entrainment within power-station cooling-water systems. The apparatus has enabled the testing of mechanical, thermal, chlorine and realistic pressure effects both alone and in combination, the range of stressors spanning the standard conditions found within a temperate coastal direct-cooled power station. Mechanical stresses affected only lobster larvae, pressure changes affected only the Acartia adults. Residual chlorine caused significant mortality of Acartia and shrimp larvae, but had no effect on lobster larvae even at 1 ppm. The temperature increment significantly affected all three species, with a synergistic effect on chlorine sensitivity in the shrimp larvae, but only temperatures higher than would be experienced in a normally-operating power station affected the copepods. The majority of individuals of each species would survive passage through a power-station system under normal conditions. It is notable that, within the species tested, generalizations from the responses of one species to those of another are not valid. PMID:14749060

  7. First record of Clausidium (Copepoda, Clausidiidae) from Brazil: a new species associated with ghost shrimps Neocallichirus grandimana (Gibbes, 1850) (Decapoda, Callianassidae)

    PubMed Central

    Kihara, Terue C.; Rocha, Carlos E. F.

    2013-01-01

    Abstract A new clausidiid copepod was found living in galleries of ghost shrimps Neocallichirus grandimana (Gibbes, 1850) in Natal, Brazil. The new species resembles to Clausidium senegalense Humes, 1957 and Clausidium vancouverense (Haddon, 1912) in the armature of P2–P5 of the female, and shares with Clausidium senegalense similar segmentation and armature of the antenna and maxilla of the female. Nevertheless, it can be easily distinguished from its congeners by the unique characteristics observed in the antenna, maxilliped and first leg of males, as well as by the anal somite, maxillule and maxilliped of the females. This new species extends the group distribution to the Southwest Atlantic and represents the first record of the genus in Brazil. A key for the identification of the species based on females of Clausidium is provided. PMID:24146565

  8. The turbidity front as a habitat for Acartia tonsa (Copepoda) in the Río de la Plata, Argentina-Uruguay

    NASA Astrophysics Data System (ADS)

    Derisio, Carla; Braverman, Mara; Gaitán, Esteban; Hozbor, Constanza; Ramírez, Fernando; Carreto, José; Botto, Florencia; Gagliardini, Domingo A.; Acha, E. Marcelo; Mianzan, Hermes

    2014-01-01

    Acartia tonsa is one of the most abundant copepod species in estuaries worldwide. In the Río de la Plata, its highest densities appear to occur in an area of low quality food (detritus): the turbidity front (TF). The objective of this study was to understand how trophic and oceanographic drivers contribute to the high densities of A. tonsa in the Río de la Plata TF. The patterns of spatial distribution and density of this species were analyzed in relation to oceanographic and biological attributes of the system. The egg production rate (EPR) in the TF was evaluated as a measure of fitness, and a stable isotope analysis indicated the possible sources of organic matter in the species' diet. This study confirmed that the highest observed densities of A. tonsa were mostly associated with the TF, where high suspended matter and low Chl-a occur. Immediately offshore from the TF, decreased copepod densities and the maximum Chl-a values were found. Females close to the estuarine turbidity maximum (ETM) had a lower EPR than those closer to the high Chl-a concentrations. Within the TF, A. tonsa apparently fed on detritus close to the ETM and phytoplankton close to the edge of the TF. The report includes a discussion of how retention processes, two layered flow and the life history strategy of A. tonsa could be contributing to the development of high densities (more than 10,000 ind m- 3) of this species in the inner estuarine zone, despite the poor quality of food available for development in that area. A. tonsa can live and prosper in areas with high turbidity and low chlorophyll concentrations. This trait exemplifies the plasticity of this species and helps explain why it is a key species in many worldwide estuaries.

  9. The identity of Limnoncaea diuncata Kokubo, 1914 (Copepoda: Poecilostomatoida) from Hokkaido, Japan, with the relegation of Diergasilus Do, 1981 to a junior synonym of Thersitina Norman, 1905.

    PubMed

    Ohtsuka, Susumu; Ho, Ju-Shey; Nagasawa, Kazuya; Morozinska-Gogol, Jolanta; Piasecki, Wojciech

    2004-01-01

    Both sexes of an ergasilid copepod, Limnoncaea diuncata Kokubo, 1914, are redescribed based on planktonic specimens collected from the type-locality in Hokkaido, Japan. Comparison of this species with Thersitina gasterostei (Pagenstecher, 1861) revealed that they are conspecific. Another ergasilid genus with two claws on the antenna, Diergasilus Do, 1981, is relegated to synonymy with Thersitina Norman, 1905. The diagnosis of Thersitina is amended. PMID:14739673

  10. Spatial and temporal distribution in density and biomass of two Pseudodiaptomus species (Copepoda: Calanoida) in the Caeté river estuary (Amazon region--North of Brazil).

    PubMed

    Magalhães, A; Costa, R M; Liang, T H; Pereira, L C C; Ribeiro, M J S

    2006-05-01

    Spatial and temporal density and biomass distribution of the planktonic copepods Pseudodiaptomus richardi and P. acutus along a salinity gradient were investigated in the Caeté River Estuary (North-Brazil) in June and December, 1998 (dry season) and in February and May, 1999 (rainy season). Copepod biomass was estimated using regression parameters based on the relation of dry weight and body length (prosome) of adult organisms. The Caeté River Estuary was characterized by high spatial and temporal variations in salinity (0.8-37.2). Exponential length-weight relationships were observed for both Pseudodiaptomus species. Density and biomass values oscillated between 0.28-46.18 ind. m-3 and 0.0022-0.3507 mg DW. m-3 for P. richardi; and between 0.01-17.02 ind. m-3 and 0.0005-0.7181 mg DW. m-3 for P. acutus. The results showed that the contribution of P. richardi for the secondary production in the Caeté River Estuary is more important in the limnetic zone than in other zones where euhaline-polyhaline regimes were predominant. However, it was not possible to observe a clear pattern of spatial and temporal distribution for P. acutus. PMID:16862295

  11. First descriptions of copepodid stages, sexual dimorphism and intraspecific variability of Mesocletodes Sars, 1909 (Copepoda, Harpacticoida, Argestidae), including the description of a new species with broad abyssal distribution

    PubMed Central

    Menzel, Lena

    2011-01-01

    Abstract Mesocletodes Sars, 1909a encompasses 37 species to date. Initial evidence on intraspecific variability and sexual dimorphism has been verified for 77 specimens of Mesocletodes elmari sp. n. from various deep-sea regions, and ontogenetic development has been traced for the first time. Apomorphies are a strong spinule-like pinna on the mx seta that is fused to the basis, P2–P4 exp3 proximal outer seta lost, P1–P4 enp2 extremely elongated, furcal rami elongated, female body of prickly appearance, female P2–P4 enp2 proximal inner seta lost. Intraspecific variability involves spinulation, ornamentation and size of the body and setation and spinulation of pereiopods. Sexually dimorphic modifications of adult females include prickly appearance of the body, P1 enp exceeds exp in length, P1 coxa externally broadened, seta of basis arising from prominent protrusion, hyaline frills of body somites ornate. Sexual dimorphism in adult males is expressed in smaller body size, haplocer A1, 2 inner setae on P2–P4 enp2 and on P5 exp, P5 basendopodal lobe with 2 setae. Some modifications allow sexing of copepodid stages. The female A1 is fully developed in CV, the male A1 undergoes extensive modifications at the last molt. P1–P4 are fully developed in CV. Mesocletodes faroerensis and Mesocletodes thielei lack apomorphies of Mesocletodes and are excluded. PMID:21594073

  12. Two new species of Ergasilus Nordmann, 1832 (Copepoda: Ergasilidae) and a redescription of Ergasilus salmini Thatcher & Brazil-Sato, 2008 from Salminus brasiliensis Cuvier and S. franciscanus Lima & Britsky (Teleostei: Characidae) in Brazil.

    PubMed

    Marques, Taísa Mendes; Boeger, Walter A; de Carvalho Brasil-Sato, Marília

    2015-01-01

    Three species of Ergasilus Nordmann, 1832 are reported from the gills of Salminus spp. in Brazil. Ergasilus salmini Thatcher & Brazil-Sato, 2008 from Salminus brasiliensis Cuvier is redescribed, based on examination of paratypes. The study revealed morphological differences from the original description, especially in the morphology of the cephalothorax and the ornamentation of antenna, antennule and legs. Ergasilus lacusauratus n. sp. described from S. brasiliensis in lake Lagoa Dourada (Paraná) differs from the only known species from this host group, E. salmini, in the shape and size of the cephalothorax and the general morphology of the egg-sacs. Ergasilus sinefalcatus n. sp. from S. franciscanus Lima & Britsky in River São Francisco (Minas Gerais) closely resembles E. pitalicus, E. coatiarus and E. leporinidis in the lack of a pectinate seta on the first exopodal segment, a feature common in species of Ergasilus in the Neotropics. Ergasilus sinefalcatus n. sp. differs from these species in the presence of a spiniform process on the coxae of legs 2, 3 and 4, an ornament never reported from freshwater species of Ergasilus in South America. PMID:25557749

  13. An annotated list of fish parasites (Isopoda, Copepoda, Monogenea, Digenea, Cestoda, Nematoda) collected from Snappers and Bream (Lutjanidae, Nemipteridae, Caesionidae) in New Caledonia confirms high parasite biodiversity on coral reef fish

    PubMed Central

    2012-01-01

    Background Coral reefs are areas of maximum biodiversity, but the parasites of coral reef fishes, and especially their species richness, are not well known. Over an 8-year period, parasites were collected from 24 species of Lutjanidae, Nemipteridae and Caesionidae off New Caledonia, South Pacific. Results Host-parasite and parasite-host lists are provided, with a total of 207 host-parasite combinations and 58 parasite species identified at the species level, with 27 new host records. Results are presented for isopods, copepods, monogeneans, digeneans, cestodes and nematodes. When results are restricted to well-sampled reef fish species (sample size > 30), the number of host-parasite combinations is 20–25 per fish species, and the number of parasites identified at the species level is 9–13 per fish species. Lutjanids include reef-associated fish and deeper sea fish from the outer slopes of the coral reef: fish from both milieus were compared. Surprisingly, parasite biodiversity was higher in deeper sea fish than in reef fish (host-parasite combinations: 12.50 vs 10.13, number of species per fish 3.75 vs 3.00); however, we identified four biases which diminish the validity of this comparison. Finally, these results and previously published results allow us to propose a generalization of parasite biodiversity for four major families of reef-associated fishes (Lutjanidae, Nemipteridae, Serranidae and Lethrinidae): well-sampled fish have a mean of 20 host-parasite combinations per fish species, and the number of parasites identified at the species level is 10 per fish species. Conclusions Since all precautions have been taken to minimize taxon numbers, it is safe to affirm than the number of fish parasites is at least ten times the number of fish species in coral reefs, for species of similar size or larger than the species in the four families studied; this is a major improvement to our estimate of biodiversity in coral reefs. Our results suggest that extinction of a coral reef fish species would eventually result in the coextinction of at least ten species of parasites. PMID:22947621

  14. First report of the presence of Acartia bispinosa Carl, 1907 (Copepoda, Calanoida) in a semi-enclosed Bay (Sharm El-Maya), northern Red Sea with some notes on its seasonal variation in abundance and body size

    PubMed Central

    El-Sherbiny, Mohsen M.; Al-Aidaroos, Ali M.

    2014-01-01

    Abstract The calanoid copepod, Acartia bispinosa Carl, 1907, is reported for the first time in the Red Sea, where it is found to be an important copepod in the mesozooplankton community structure of the Sharm El-Maya Bay. Female and male are fully redescribed and illustrated of as the mouthparts of this species have never previously been described and figured. Acartia bispinosa was collected in the plankton samples throughout the year and showed two peaks of abundance, a pronounced one in April (4234 individuals m-3), and second smaller peak during November (1784 individuals m-3). The average total length of females varied between 1.32 and 1.53 mm at the end of June and January respectively. For males, the average total length fluctuated between 1.07 and 1.16 mm at end of June and March respectively. Temperature showed an inverse relationship with the body length (P > 0.001) and seemed to be one of the prime factors affecting the body length of both sexes. PMID:25349502

  15. Endemism of subterranean Diacyclops in Korea and Japan, with descriptions of seven new species of the languidoides-group and redescriptions of D. brevifurcus Ishida, 2006 and D. suoensis Ito, 1954 (Crustacea, Copepoda, Cyclopoida)

    PubMed Central

    Karanovic, Tomislav; Grygier, Mark J.; Lee, Wonchoel

    2013-01-01

    Abstract Copepods have been poorly studied in subterranean habitats in Korea. Previous records have indicated mostly the presence of species already described from Japan, with very few endemic elements. This commonality has usually been explained by repeated dispersal across the land bridges that connected the two countries several times during the Pleistocene glacial cycles. However, the Korean Peninsula is known for pockets of Cambrian and Ordovician carbonate rocks, with more than 1,000 caves already having been explored. The relative isolation of these carbonate pockets makes for an enormous speciation potential, and the development of a high level of short-range endemism of subterranean copepods should be expected. Representatives of the genus Diacyclops Kiefer, 1927 are here investigated from a range of subterranean habitats in South Korea, with comparative material sampled from central Honshu in Japan. Morphological analyses of microcharacters, many of which are used in cyclopoid taxonomy for the first time herein, reveal high diversity in both countries. No subterranean species is found in common, although the existence of four sibling species pairs in Korea and Japan may be indicative of relatively recent speciation. We describe seven new stygobiotic species, including three from Korea (Diacyclops hanguk sp. n., Diacyclops leeae sp. n., and Diacyclops parasuoensis sp. n.) and four from Japan (Diacyclops hisuta sp. n., Diacyclops ishidai sp. n., Diacyclops parahanguk sp. n., and Diacyclops pseudosuoensis sp. n.). Diacyclops hanguk, Diacyclops parasuoensis, Diacyclops ishidai, and Diacyclops parahanguk are described from newly collected material, while the other three new species are proposed for specimens previously identified as other, widely distributed species. Diacyclops brevifurcus Ishida, 2006 is redescribed from the holotype female, and Diacyclops suoensis Ito, 1954 is redescribed from material newly collected near the ancient Lake Biwa in Japan. This research provides evidence for the importance of subterranean habitats as reservoirs of biodiversity, and also demonstrates the inadequacy of current morphological methods of identifying closely related species of copepods. The disproportionately high diversity discovered around Lake Biwa provides further evidence in support of the hypothesis about the role of ancient lakes as biodiversity pumps for subterranean habitats. A key to the East Asian species of the languidoides-group is provided. PMID:23653520

  16. Stage-V copepodites of Calanus sinicus and Calanus jashnovi (Copepoda: Calanoida) in mesopelagic zone of Sagami Bay as identified with genetic markers, with special reference to their vertical distribution

    NASA Astrophysics Data System (ADS)

    Nonomura, Takumi; Machida, Ryuji J.; Nishida, Shuhei

    2008-04-01

    We applied genetic makers to identify Calanus species occurring in Sagami Bay, Japan, in order to investigate their vertical distribution in the upper 1000 m. First, interspecific genetic distances of three gene loci, mitochondrial small ribosomal RNA (srRNA), nuclear internal transcribed spacers 1 (ITS1) and 2 (ITS2), were estimated from morphologically distinguishable adult females of Calanus sinicus, Calanus jashnovi and Calanus pacificus that were collected from Sagami Bay, the Kuroshio Extension and the Oyashio region, respectively. The highest levels of interspecific genetic distance were observed in srRNA, followed by ITS1 and ITS2. The intraspecific genetic distances within C. sinicus were much lower than the interspecific genetic distances, indicating that DNA sequences in these loci are consistent with the morphological differences. This information was used as a criterion for species identification based on DNA sequence variation, and allowed us to identify the fifth copepodites (CVs) or younger stages of these species. Next, the vertical distribution of Calanus species was investigated in Sagami Bay in May 2006, on the basis of a stratified sampling in the upper 1000 m. By applying the genetic markers, 23 individuals comprising all copepodite stages were allocated into either C. sinicus or C. jashnovi, and the small- and large-sized CVs were identified as C. sinicus and C. jashnovi, respectively. The total abundance of C. sinicus was highest at 0-50 m and decreased with depth. On the contrary, CV individuals of C. sinicus were abundant not only in 0-50 m but also below 200 m with minimum occurrences in 150-200 m depth. C. jashnovi was much less abundant than C. sinicus and comprised of only CIV and CV which occurred in the upper 100 m and deeper than 50 m depths, respectively. The abundance of C. sinicus in the 1000-m water column of Sagami Bay was at a level comparable to that in shelf waters, suggesting the importance of off-shelf individuals in the biological production and organic transport in the respective areas.

  17. A new species of Leposphilus Hesse, 1866 (Copepoda: Philichthyidae) parasitic in the interorbital canals of the whitemouth croaker Micropogonias furnieri (Desmarest) (Sciaenidae) off Brazil with an amended diagnosis of the genus.

    PubMed

    Paschoal, Fabiano; Nagasawa, Kazuya; Luque, José Luis

    2016-06-01

    A new species of the monotypic genus Leposphilus Hesse, 1866 (Cyclopoida: Philichthyidae), Leposphilus vogti n. sp., is described based on adult female and male specimens from the interorbital canals of Micropogonias furnieri (Desmarest) (Sciaenidae) in Sepetiba Bay, State of Rio de Janeiro, Brazil. The new species differs from its only congener, L. labrei Hesse, 1866, by the following combination of characters in the adult female: a globular cephalosome, a two-segmented maxilla, and fourth abdominal somite fused to caudal ramus; and in the adult male: presence of maxilliped, leg 3 with five setae, and caudal rami tipped with six setae. In addition, an amendment of diagnosis of Leposphilus is provided based on the characters of the new species. Previous records of philichthyid copepods from actinopterygians in the Atlantic and Pacific Oceans off the American continent are also given. PMID:27221003

  18. New record and redescription of Calanopia thompsoni A. Scott, 1909 (Copepoda, Calanoida, Pontellidae) from the Red Sea, with notes on the taxonomic status of C. parathompsoni Gaudy, 1969 and a key to species.

    PubMed

    Al-Aidaroos, Ali M; Salama, Adnan J; El-Sherbiny, Mohsen M

    2016-01-01

    During a plankton sampling programme around Al-Wajh area, Saudi Arabian coast of the northern Red Sea, a copepod Calanopia thompsoni A. Scott, 1909 (Calanoida: Pontellidae) was reported for the first time in the Red Sea. Both sexes are fully redescribed and compared to previous descriptions as well as the closely related species, Calanopia parathompsoni. The zoogeographical distribution of the species confirms that it is of Indo-Pacific origin. A dichotomous key for the identification of males and females of the species of Calanopia is included. PMID:26865813

  19. New record and redescription of Calanopia thompsoni A. Scott, 1909 (Copepoda, Calanoida, Pontellidae) from the Red Sea, with notes on the taxonomic status of C. parathompsoni Gaudy, 1969 and a key to species

    PubMed Central

    Al-Aidaroos, Ali M.; Salama, Adnan J.; El-Sherbiny, Mohsen M.

    2016-01-01

    Abstract During a plankton sampling programme around Al-Wajh area, Saudi Arabian coast of the northern Red Sea, a copepod Calanopia thompsoni A. Scott, 1909 (Calanoida: Pontellidae) was reported for the first time in the Red Sea. Both sexes are fully redescribed and compared to previous descriptions as well as the closely related species, Calanopia parathompsoni. The zoogeographical distribution of the species confirms that it is of Indo-Pacific origin. A dichotomous key for the identification of males and females of the species of Calanopia is included. PMID:26865813

  20. Moving Cages Further Offshore: Effects on Southern Bluefin Tuna, T. maccoyii, Parasites, Health and Performance

    PubMed Central

    Kirchhoff, Nicole T.; Rough, Kirsty M.; Nowak, Barbara F.

    2011-01-01

    The effects of offshore aquaculture on SBT health (particularly parasitic infections and haematology) and performance were the main aim of this study. Two cohorts of ranched Southern Bluefin tuna (SBT) (Thunnus maccoyii) were monitored throughout the commercial season, one maintained in the traditional near shore tuna farming zone and one maintained further offshore. SBT maintained offshore had reduced mortality, increased condition index at week 6 post transfer, reduced blood fluke and sealice loads, and haematological variables such as haemoglobin or lysozyme equal to or exceeding near shore maintained fish. The offshore cohort had no Cardicola forsteri and a 5% prevalence of Caligus spp., compared to a prevalence of 85% for Cardicola forsteri and 55% prevalence for Caligus spp. near shore at 6 weeks post transfer. This study is the first of its kind to examine the effects of commercial offshore sites on farmed fish parasites, health and performance. PMID:21901129

  1. A new species of Copepoda Harpacticoida, Xylora calyptogenae spec. n., with a carnivorous life-style from a hydrothermally active submarine volcano in the New Ireland Fore-Arc system (Papua New Guinea) with notes on the systematics of the Donsiellinae Lang, 1948

    NASA Astrophysics Data System (ADS)

    Willen, Elke

    2006-12-01

    A new species of harpacticoid copepods, Xylora calyptogenae spec. n., from Edison Seamount, a hydrothermally active submarine volcano in the New Ireland Fore-Arc system (Papua New Guinea) is described. The new species belongs to the Donsiellinae Lang, 1944, a highly specialised taxon, the members of which have previously been encountered only in association with decaying wood and/or wood-boring isopods. A closer relationship of the Donsiellinae with the Pseudotachidiidae Lang, 1936, can be stated on the basis of characteristics concerning the setation and/or segmentation of A1, A2, Mxl, Mxp, the shape of the female P5, anal somite, sexual dimorphisms on P2 and P3 and missing caudal seta I. Within the Pseudotachidiidae, the Donsiellinae again can be well characterized, e.g. by the setation and segmentation of A2, Mxl, swimming-legs, the shape of P1, female P5, male P2, sexual dimorphism and male P5. The Donsiellinae share some apomorphies with the pseudotachidiid subtaxon Paranannopinae Por, 1986: setation/segmentation of Mx, P1, A1. X. calyptogenae spec. n. is more closely related to Xylora bathyalis Hicks 1988 living in the deep sea wood substrata in New Zealand waters. Some traits of the evolutionary history of the Donsiellinae become evident, probably starting from the more primitive deep sea taxa X .calyptogenae spec. n., which lives in the hydrothermal seafloor in the absence of decaying wood, and X. bathyalis, which is found in decaying wood but not necessarily associated with the wood-boring isopod Limnoria Leach, 1814, towards the more advanced genera such as Donsiella Stephensen, 1936, which invades shallow waters and, further, clings to Limnoria, forming a close and, for the copepod, probably obligatory association. The specialised mouthparts of X. calyptogenae spec. n. seem to facilitate the grabbing and fixing of larger and/or active food items. This is confirmed by the presence of a large prey organism, presumably a copepod, consumed either alive or dead, in the gut of one of the available specimens. This morphology of the mouthparts is also shared by the closely related X. bathyalis.

  2. Comparison of food compositon of clupeid fishes in the Bohai Sea

    NASA Astrophysics Data System (ADS)

    Li, Jun; Wang, Hong

    1992-12-01

    Analysis of stomach contents of samples of clupeid fishes (Japanese anchovy, half-fin anchovy, zunas' scaled sardine, rednosed glassnose and tapertail anchovy) collected from the catches of a 1982 1984 fishery resource survey showed they are zooplanktonivorous. Similar food groups, such as copepoda. Chaetognatha, Amphipoda and Mysidacea were found in the stomach. Dietary similarity coefficients were studied to evaluate the degree of similarity in the dietary species-pairs. Seasonal variation is discussed.

  3. [Abundance and biomass of meiobenthos in Southern Yellow Sea in winter].

    PubMed

    Zhang, Yan; Zhang, Zhi-nan; Huang, Yong; Hua, Er

    2007-02-01

    A two cruises investigation on the meiobenthos in the continental shelf of Southern Yellow Sea was made in January 2003 and January 2004. The results showed that the average abundance of meiobenthos was (954.20 +/- 269.47) ind x 10 cm(-2) and ( 1 186.12+/- 486.07) ind x 10 cm(-2), and the biomass was (954.38+/-403.93) microg x10 cm(-2) and (1 120.72+/-487.21 ) mg x 10 cm(-2) in January 2003 and January 2004, respectively, with no significant difference observed. A total of twenty meiobenthic groups were identified. Free-living marine nematodes was the most dominant group in abundance, with a relative dominance of 87% in 2003 and 90% in 2004, followed by benthic harpacticoids copepoda, polychaeta and kinorhyncha. In terms of biomass, the dominant groups were nematoda (34% -38%), polychaeta (25% -33%), ostracoda (9% -22%) and copepoda (8%). 96. 64% of the meiobenthos distributed in the top 0-5 cm of sediment, while 72. 48% of nematode and 89. 46% of copepoda were in the top 0-2 cm of the sediment. Meiobenthos biomass had significant correlation with the sand and silt contents of sediment and the content of Chl-a. The species composition and biodiversity analyses of six representative stations indicated that there were three meiobenthos communities in the study area, i. e. , inshore, cold waters mass, and transitional communities. PMID:17450749

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

    PubMed

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

    2015-06-01

    The knowledge of the biodiversity of parasitic copepods in South Korea is increasing. Interestingly we report here, some parasitic copepods considered as the first record of findings from Korea. Nine species of parasitic copepods (Siphonostomatoida) including six genera of three different families [Caligidae (7), Lernaeopodidae (1), Lernanthropidae (1)] were recovered from eight species of wild fishes in Korea: 1) Caligus hoplognathi Yamaguti & Yamasu, 1959 (♀, ♂) from the body surface of barred knifejaw Oplegnathus fasciatus (Temminck & Schlegel); 2) Caligus lagocephali Pillai, 1961 (♀) from the gills of panther puffer Takifugu pardalis (Temminck & Schlegel); 3) Euryphorus brachypterus (Gerstaecker, 1853) (♀, ♂) from the opercular cavity of Atlantic bluefin tuna Thunnus thynnus (Linnaeus); 4) Euryphorus nordmanni Milne Edwards, 1840 (♀, ♂) from the opercular cavity of common dolphin fish Coryphaena hippurus Linnaeus; 5) Gloiopotes huttoni (Thomson) (♀, ♂) from the body surface of black marlin Istiompax indica (Cuvier); 6) Lepeophtheirus hapalogenyos Yamaguti & Yamasu, 1959 (♀) from the gill filaments of O. fasciatus; 7) Lepeophtheirus sekii Yamaguti, 1936 (♀, ♂) from the body surface of red seabream Pagrus major (Temminck & Schlegel); 8) Brachiella thynni Cuvier, 1830 (♀) from the body surface of longfin tuna or albacore Thunnus alalunga (Bonnaterre); 9) Lernanthropinus sphyraenae (Yamaguti & Yamasu, 1959) (♀) from the gill filaments of moon fish Mene maculata (Bloch & Schneider). Since the female was already reported in Korea, it is a new record for the male of C. hoplognathi. A checklist for the parasitic copepods of the family Caligidae, Lernaeopodidae and Lernanthropidae of Korea is provided. PMID:26691264

  5. Copepods and larvae of nematodes parasitizing (correction of parasiting) the white mullet Mugil curema (Valenciennes, 1836): indicators of anthropogenic impacts in tropical coastal lagoons?

    PubMed

    Fajer-Avila, E J; García-Vásquez, A; Plascencia-González, H; Ríos-Sicairos, J; García-De La Parra, L M; Betancourt-Lozano, M

    2006-11-01

    The relationship between parasites and environmental stress were studied in two tropical coastal lagoons of Northwest Mexico: Urias estuary (highly polluted) and Teacapan estuary (slightly polluted). Metazoan parasites were examined in 292 white mullet (Mugil curema) specimens collected bimonthly during a year from both systems. Haliotrema mugilinus, Metamicrocotyla macracantha, Ergasilus sp., Caligus sp., Holobomolochus sp., and Lernaeopodidae were found in gills, while Contracaecum sp. larvae III was found liver, hepatic portal vein and kidneys. Ecological indices were influenced by the slightly higher number of parasitic species in Urias compared to Teacapan, as well as the clear dominance of two species: Ergasilus sp. and Contracaecum sp. in both systems. In fact, Ergasilus sp. showed considerably higher abundance in Urias, possibly indicating that its success was a result of adverse conditions affecting the host, while Contracaecum sp showed higher abundances in Teacapan, suggesting that the environmental conditions occurring in Urias could have produced negative impacts on the nematode's infective potential. PMID:16758278

  6. Common plankton of Twin Lakes, Colorado

    SciTech Connect

    Lieberman, D.M.

    1983-02-01

    A series of studies is being performed to evaluate the effects of the Mt. Elbert Pumped-Storage Powerplant on the ecology of Twin Lakes. Twin Lakes are a pair of connected dimictic lakes, formed as the result of glacial action on alluvial deposits. This report presents a taxonomic species study of the common plankton collected since 1974 from Twin Lakes. A total of 11 zooplankters and 14 phytoplankters were identified from the limnetic zone of Twin Lakes and the associated Mt. Elbert Forebay. The four divisions of zooplankton included four species of Rotifera (rotifer), three species of Copepoda (copepod), three species of Cladocera (cladoceran), and one species of Mysidacea (opossum shrimp).

  7. The InfThe Influence Of Subsample Size In A Study Of Freshwater Zooplantonluence Of Subsample Size In A Study Of Freshwater Zooplanton

    SciTech Connect

    Bowers, James A.

    2005-08-15

    The influence of subsample size on counting precision and estimates of taxa richness is documented for a freshwater zooplankton biomonitoring program. Subsample variability was related to subsample size. The mean and median coefficient of variation for cladocera and copepoda were below 30% at counts of 50-100 individuals. Jaccard's similarity coefficient stabilized at counts of 100-150 individuals as did the total number of zooplankton taxa identified. These data suggest that counting more organisms in subsamples or more than one subsample per sample may do relatively little to better characterize samples.

  8. Feeding habits and food composition of half-fin anchovy, Setipinna taty (C et V) in the Bohai Sea

    NASA Astrophysics Data System (ADS)

    Gu, Hong

    1990-09-01

    Analysis of the contents of 3,479 stomachs of half-fin anchovy (taken monthly from April 1982 to May 1983 from the Bohai Sea) shows that half-fin anchovy is a zooplanktivorous fish; the young fish feeds mainly on Copepoda while the adult fish feeds mainly on Mysidacea and Acetes chinensis; the food composition has a seasonal change, the main food is Mysidacea in spring but Acetes chinensis in summer and fall; the feeding intensity is closely related to its spawning.

  9. The Impact of Water Table Drawdown and Drying on Subterranean Aquatic Fauna in In-Vitro Experiments

    PubMed Central

    Stumpp, Christine; Hose, Grant C.

    2013-01-01

    The abstraction of groundwater is a global phenomenon that directly threatens groundwater ecosystems. Despite the global significance of this issue, the impact of groundwater abstraction and the lowering of groundwater tables on biota is poorly known. The aim of this study is to determine the impacts of groundwater drawdown in unconfined aquifers on the distribution of fauna close to the water table, and the tolerance of groundwater fauna to sediment drying once water levels have declined. A series of column experiments were conducted to investigate the depth distribution of different stygofauna (Syncarida and Copepoda) under saturated conditions and after fast and slow water table declines. Further, the survival of stygofauna under conditions of reduced sediment water content was tested. The distribution and response of stygofauna to water drawdown was taxon specific, but with the common response of some fauna being stranded by water level decline. So too, the survival of stygofauna under different levels of sediment saturation was variable. Syncarida were better able to tolerate drying conditions than the Copepoda, but mortality of all groups increased with decreasing sediment water content. The results of this work provide new understanding of the response of fauna to water table drawdown. Such improved understanding is necessary for sustainable use of groundwater, and allows for targeted strategies to better manage groundwater abstraction and maintain groundwater biodiversity. PMID:24278111

  10. Unexpectedly higher metazoan meiofauna abundances in the Kuril-Kamchatka Trench compared to the adjacent abyssal plains

    NASA Astrophysics Data System (ADS)

    Schmidt, Christina; Martínez Arbizu, Pedro

    2015-01-01

    We studied meiofauna standing stocks and community structure in the Kuril-Kamchatka Trench and its adjacent abyssal plains in the northwestern Pacific Ocean. In general, the Nematoda were dominant (93%) followed by the Copepoda (4%). Nematode abundances ranged from 87% to 96%; those of copepods from 2% to 7%. The most diverse deployment yielded 17 taxa: Acari, Amphipoda, Annelida, Bivalvia, Coelenterata, Copepoda, Cumacea, Gastrotricha, Isopoda, Kinorhyncha, Loricifera, Nematoda, Ostracoda, Priapulida, Tanaidacea, Tantulocarida, and Tardigrada. Nauplii were also present. Generally, the trench slope and the southernmost deployments had the highest abundances (850-1392 individuals/cm2). The results of non-metric multidimensional scaling indicated that these deployments were similar to each other in meiofauna community structure. The southernmost deployments were located in a zone of higher particulate organic carbon (POC) flux (g Corg m-2 yr-1), whereas the trench slope should have low POC flux due to depth attenuation. Also, POC and abundance were significantly correlated in the abyssal plains. This correlation may explain the higher abundances at the southernmost deployments. Lateral transport was also assumed to explain high meiofauna abundances on the trench slope. Abundances were generally higher than expected from model results. ANOSIM revealed significant differences between the trench slope and the northern abyssal plains, between the central abyssal plains and the trench slope, between the trench slope and the southern abyssal plains, between the central and the southern abyssal plains, and between the central and northern deployments. The northern and southern abyssal plains did not differ significantly. In addition, a U-test revealed highly significant differences between the trench-slope and abyssal deployments. The taxa inhabited mostly the upper 0-3 cm of the sediment layer (Nematoda 80-90%; Copepoda 88-100%). The trench-slope and abyssal did not differ

  11. Feeding ecology of waterfowl wintering on evaporation ponds in California

    USGS Publications Warehouse

    Euliss, N.H., Jr.; Jarvis, R.L.; Gilmer, D.S.

    1991-01-01

    We examined the feeding ecology of Northern Pintails (Anas acuta), Northern Shovelers (A. clypeata), and Ruddy Ducks (Oxyura jamaicensis) wintering on drainwater evaporation ponds in California from 1982 through 1984. Pintails primarily consumed midges (Chironomidae) (39.3%) and widegeongrass (Ruppia maritima) nutlets (34.6%). Shovelers and Ruddy Ducks consumed 92.5% and 90.1% animal matter, respectively. Water boatmen (Corixidae) (51.6%), rotifers (Rotatoria) (20.4%), and copepods (Copepoda) (15.2%) were the most important Shoveler foods, and midges (49.7%) and water boatmen (36.0%) were the most important foods of Ruddy Ducks. All three species were opportunistic foragers, shifting their diets seasonally to the most abundant foods given their behavioral and morphological attributes.

  12. Short-term Variations of the Zooplankton Community Near the Straits of Messina (North-eastern Sicily): Relationships with the Hydrodynamic Regime

    NASA Astrophysics Data System (ADS)

    Zagami, G.; Badalamenti, F.; Guglielmo, L.; Manganaro, A.

    1996-05-01

    Zooplankton samples were collected near the Straits of Messina over two 24-h periods in May 1988 and January 1989. In this area, the complex system of currents which circulate through the Straits still affects both biotic and hydrological factors even near the shore. Copepoda, Cladocera, Chaetognatha and Appendicularia together with some meroplanktonic taxa make up the zooplankton assemblage collected during the two periods. The community structure changes greatly in terms of biomass and density during the 24-h cycle, and in terms of species composition between the two sampling months. The variability of biomass and density could be ascribed to the effect of the special current system in the area, whereas variations in species composition could be related to the seasonality demonstrated by the zooplankton community. These factors combined are responsible for the peculiar condition described in the paper.

  13. Land Use and Hydrogeological Characteristics Influence Groundwater Invertebrate Communities.

    PubMed

    Tione, María Laura; Bedano, José Camilo; Blarasin, Mónica

    2016-08-01

    We examine the influence of land use and hydrogeological characteristics on the abundance, composition and structure of groundwater invertebrate communities in a loessic aquifer from Argentina. Seven wells, selected according to surrounding land use and hydrogeological characteristics, were sampled twice. Groundwater was characterized as sodium bicarbonate, bicarbonate sulfate or sulfate type. NO3(-) was detected in all samples. Land use in the area surrounding the well, unsaturated zone thickness and geochemical characteristics of groundwater influenced the abundance, composition and community structure of groundwater invertebrates. Copepoda, Oligochaeta, Cladocera, Ostracoda and Amphipoda were highly influenced by land use, particularly by point pollution sources that produced higher abundance and changes in taxonomic composition. The lowest invertebrate abundance was observed at the wells situated in areas with the thickest unsaturated zone. Groundwater salinity and geochemical type influenced the presence of certain species, particularly Stygonitocrella sp. PMID:27456146

  14. Chondracanthid copepod parasites of dories (Zeiformes: Zeidae) with the description of a new species of Chondracanthus from waters off northern Argentina.

    PubMed

    Braicovich, Paola E; Lanfranchi, Ana L; Incorvaia, Inés S; Timi, Juan T

    2013-09-01

    A new species of parasitic copepod, Chondracanthus hoi sp. n. (Copepoda: Chondracanthidae), is described based on specimens of both sexes collected from the buccal cavity and gill arches of the silvery john dory, Zenopsis conchifer (Lowe) (Zeiformes: Zeidae), from waters off northern Argentina (35-36 degrees S, 53-54 degrees W). Female of C. hoi differs from its congeners by the following combination of characters: presence of five pairs of trunk processes, antennule with four knobs tipped with small setae and absence of denticles on the terminal process of maxilla. Chondracanthids and zeiform fishes have been proposed as an example of co-speciation; this assumption is derived from a series of analyses based on incomplete records of both geographical distribution and host range of some parasite species, as well as misidentification offish hosts. These inconsistences observed during our bibliographical analyses are also discussed. PMID:24261137

  15. Carnivory during Ontogeny of the Plagioscion squamosissimus: A Successful Non-Native Fish in a Lentic Environment of the Upper Paraná River Basin.

    PubMed

    Neves, Mayara Pereira; Delariva, Rosilene Luciana; Guimarães, Ana Tereza Bittencourt; Sanches, Paulo Vanderlei

    2015-01-01

    This study evaluated feeding patterns and ontogenetic variations in a non-native fish species (Plagioscion squamosissimus) in an isolated lake in the Upper Paraná River floodplain. Quarterly samplings were performed from April 2005 to February 2006 using plankton nets to capture larvae, seining nets for juveniles, and gill nets and trammel for adults. Stomach contents (n = 378) were examined according to the volumetric method in which the volume of each food item was estimated using graduated test tubes or a glass counting plate. During early development (larval stage), P. squamosissimus consumed mainly Cladocera and Copepoda. Juveniles showed a more diverse diet, including shrimp (Macrobrachium amazonicum), fish, aquatic insects (Trichoptera, Ephemeroptera, Chironomidae and pupae of Diptera) and plants. It was notable the high proportion of cannibalism (23.3%) in this stage. Adults consumed predominantly shrimp and fish. The use of food resources varied significantly between development stages (ANOSIM; r = 0.458; p<0.005), showing changes in food preferences during ontogeny. The Similarity Percentage Analysis (SIMPER) indicated that Cladocera and Copepoda were responsible for the differences observed between the larval stages of pre-flexion, flexion and post-flexion. M. amazonicum and Chironomidae were responsible for the differences between juvenile and larval stages, while M. amazonicum and other fishes caused the differences between adults and other ontogenetic stages. These results are confirmed by the relationship between standard length and developmental periods (ANCOVA; r2 = 0.94; p<0.0001). In general, there were low values of trophic niche breadth. The essentially carnivorous habit from the early stages of P. squamosissimus and the predominant use of M. amazonicum by adults have important roles in feeding patterns of the species, suggesting a major contribution to its success and establishment, especially in lentic environments. PMID:26524336

  16. Carnivory during Ontogeny of the Plagioscion squamosissimus: A Successful Non-Native Fish in a Lentic Environment of the Upper Paraná River Basin

    PubMed Central

    Neves, Mayara Pereira; Delariva, Rosilene Luciana; Guimarães, Ana Tereza Bittencourt; Sanches, Paulo Vanderlei

    2015-01-01

    This study evaluated feeding patterns and ontogenetic variations in a non-native fish species (Plagioscion squamosissimus) in an isolated lake in the Upper Paraná River floodplain. Quarterly samplings were performed from April 2005 to February 2006 using plankton nets to capture larvae, seining nets for juveniles, and gill nets and trammel for adults. Stomach contents (n = 378) were examined according to the volumetric method in which the volume of each food item was estimated using graduated test tubes or a glass counting plate. During early development (larval stage), P. squamosissimus consumed mainly Cladocera and Copepoda. Juveniles showed a more diverse diet, including shrimp (Macrobrachium amazonicum), fish, aquatic insects (Trichoptera, Ephemeroptera, Chironomidae and pupae of Diptera) and plants. It was notable the high proportion of cannibalism (23.3%) in this stage. Adults consumed predominantly shrimp and fish. The use of food resources varied significantly between development stages (ANOSIM; r = 0.458; p<0.005), showing changes in food preferences during ontogeny. The Similarity Percentage Analysis (SIMPER) indicated that Cladocera and Copepoda were responsible for the differences observed between the larval stages of pre-flexion, flexion and post-flexion. M. amazonicum and Chironomidae were responsible for the differences between juvenile and larval stages, while M. amazonicum and other fishes caused the differences between adults and other ontogenetic stages. These results are confirmed by the relationship between standard length and developmental periods (ANCOVA; r2 = 0.94; p<0.0001). In general, there were low values of trophic niche breadth. The essentially carnivorous habit from the early stages of P. squamosissimus and the predominant use of M. amazonicum by adults have important roles in feeding patterns of the species, suggesting a major contribution to its success and establishment, especially in lentic environments. PMID:26524336

  17. [Abundance and biomass of meiobenthos in Lingdingyang Bay of Pearl River Estuary].

    PubMed

    Zhang, Jing-huai; Gao, Yang; Fang, Hong-da

    2011-10-01

    An investigation was conducted on the meiobenthic abundance and biomass in the Lingdingyang Bay of Pearl River Estuary in July-August 2006 (summer), April 2007 (spring), and October 2007 (autumn). A total of 15 meiobenthic groups were recorded, including Nematoda, Copepoda, Polychaeta, Ostracoda, Kinorhyncha, Amphipoda, Cumacea, Tanaidacea, Gnathostomulida, Nemertea, Gastropoda, Bivalvia, Sipuncula, Echiura, and other unidentified taxa. The average abundance of the meiobenthos in spring, summer, and autumn was 272.1 +/- 281.9, 165.1 +/- 147.1 and 246. 4 +/- 369.3 ind 10 cm(-2), and Nematoda was the most dominant group in abundance, accounting for 86.8%, 83.5%, and 93.4% of the total, respectively, followed by Polychaeta, and benthic Copepoda. The meiobenthic abundance had an uneven vertical distribution. 54.1% of the meibenthos were in 0-2 cm sediments, 35.2% were in 2-5 cm sediments, and 10.8% were in 5-10 cm sediments. 87.4% of nematodes were distributed in 0-5 cm sediments. The average biomass of the meiobenthos in spring, summer, and autumn was 374.6 +/- 346.9, 274.1 +/- 352.2, and 270.8 +/- 396.0 microg 10 cm(-2), and Polychaeta was the most dominant group in biomass, accounting for 30.1%, 46.7% and 46.0%, respectively, followed by Nematoda (25.2%, 20.1%, and 34.0%), and Ostracoda (20.6%, 15.3%, and 14.8%). The horizontal distribution of the meiobenthos had a trend of increasing from north to south, and being higher at east than at west. The meiobenthic abundance and biomass had significant positive correlations with water depth. PMID:22263483

  18. Mesozooplankton distribution near an active volcanic island in the Andaman Sea (Barren Island).

    PubMed

    Pillai, Honey U K; Jayaraj, K A; Rafeeq, M; Jayalakshmi, K J; Revichandran, C

    2011-05-01

    The study addresses the distribution and diversity of mesozooplankton near the active volcano-Barren Island (Andaman Sea) in the context of persistent volcanic signature and warm air pool existing for the last few months. Sampling was done from the stations along the west and east side of the volcano up to a depth of 1,000 m during the inter monsoon (April) of 2006. Existence of feeble warm air pool was noticed around the Island (Atm. Temp. 29°C). Sea surface temperature recorded as 29.9°C on the west and 29.6°C on the east side stations. High mesozooplankton biomass was observed in the study area than the earlier reports. High density and biomass observed in the surface layer decreased significantly to the deeper depths. Lack of correlation was observed between mesozooplankton biomass and density with chl. a. Twenty-three mesozooplankton taxa were observed with copepoda as the dominant taxa followed by chaetognatha. The relative abundance of chaetognatha considerably affected the copepod population density in the surface layer. A noticeable feature was the presence of cumaceans, a hyperbenthic fauna in the surface, mixed layer and thermocline layer on the western side station where the volcano discharges in to the sea. The dominant order of copepoda, the calanoida was represented by 52 species belonging to 17 families. The order poecilostomatoida also had a significant contribution. Copepods exhibited a clear difference in their distribution pattern in different depth layers. The families Calanidae and Pontellidae showed a clear dominance in the surface whereas small-sized copepods belonging to the families Clausocalanidae and Paracalanidae were observed as the predominant community in the mixed layer and thermocline layer depth. Families Metridinidae, Augaptilidae and Aetideidae were observed as dominant in deeper layers. PMID:20717718

  19. Meiobenthic gradients with special reference to Plathelminthes and Polychaeta in an estuarine salt marsh creek—a small-scale model for boreal tidal coasts?

    NASA Astrophysics Data System (ADS)

    Hellwig-Armonies, Monika; Armonies, Werner

    1987-06-01

    Environmental conditions in salt marsh creeks are intermediate between the open tidal coast and estuaries. A large salt marsh creek at the island of Sylt (North Sea) was studied in order to test whether its fauna is more similar to that of the open tidal coast or to that of estuaries. Because of a sandy bar at the seaward opening, the tidal range is only 10 cm in the creek, and the water level never drops below the level of the sand bar. Zoobenthos in the sandy bottom and on the sandy shores was studied at both ends and in the middle of the creek. Polychaeta and Plathelminthes were determined to species level. On an average, 2115 metazoans were found below 10 cm2 of surface area. At the seaward end of the creek, abundance and taxonomic composition are similar to that of the adjoining Wadden area. Nematoda are the dominant taxon, followed by Copepoda, Plathelminthes and Oligochaeta. Taxonomic composition is different at the landward end. Plathelminthes and Nematoda are most abundant followed by Copepoda. Both Oligochaeta and Polychaeta are scarce at these newly eroded sites. Plathelminth abundance at the landward end of the creek is exceptionally high (770 935·10 cm-2). Contrary to what is generally found in estuaries, the species density of Plathelminthes shows a significant increase toward the land. The species composition of Polychaeta and Plathelminthes indicates that the sites below mean high tide level of the creek correspond to the adjacent eulittoral Wadden area while the fauna of the supralittoral sites of the creek is similar to the fauna of supralittoral tidal coasts. Typical sublittoral species did not occur in the salt marsh creek. Thus, salt marsh creeks may be regarded as a small-scale model for the tidal coast. In context with the results obtained, the definition of estuaries is discussed.

  20. Spatial and temporal variations in deep-sea meiofauna assemblages in the Marginal Ice Zone of the Arctic Ocean

    NASA Astrophysics Data System (ADS)

    Hoste, Eveline; Vanhove, Sandra; Schewe, Ingo; Soltwedel, Thomas; Vanreusel, Ann

    2007-01-01

    In order to understand the response of the deep-sea meiobenthos to a highly varying, ice-edge-related input of phytodetritus, we investigated the abundance and composition of the meiobenthos at the arctic long-term deep-sea station HAUSGARTEN (79°N, 4°E) along a bathymetric transect (1200-5500 m water depth) over 5 consecutive years (from 2000 to 2004) in relation to changes in environmental conditions. Results showed high sediment-bound pigment concentrations (chlorophyll a and degradation products) ranging from 4.5 to 41.6 μg/cm 3, and coinciding high meiobenthic densities ranging from 149±3 to 3409±525 ind/10 cm 2. Nematodes dominated the metazoan meiofaunal communities at every depth and time (85-99% of total meiofauna abundance), followed by harpacticoid copepods (0-4.6% of total meiofauna abundance). The expected pattern of gradually decreasing meiobenthic densities with increasing water depth was not confirmed. Instead, the bathymetric transect could be subdivided into a shallow area with equally high nematode and copepod densities from 1000 to 2000 m water depth (means: 2259±157 Nematoda/10 cm 2, and 50±4 Copepoda/10 cm 2), and a deeper area from 3000 to 5500 m water depth with similar low nematode and copepod densities (means: 595±52 Nematoda/10 cm 2, and 11±2 Copepoda/10 cm 2). Depth-related investigations on the meiobenthos at the HAUSGARTEN site showed a significant correlation between meiobenthos densities, microbial exo-enzymatic activity (esterase turnover) and phytodetrital food availability (chlorophyll a and phaeophytines). In time-series investigations, our data showed inter-annual variations in meiofauna abundance. However, no consistent relationship between nematode and copepod densities, and measures for organic matter input were found.

  1. Synoptic patterns of meiofaunal and macrofaunal abundances and specific composition in littoral sediments

    NASA Astrophysics Data System (ADS)

    Armonies, Werner; Hellwig-Armonies, Monika

    1987-03-01

    During recent years, many investigations on small zoobenthos have been performed at the island of Sylt. As these studies were carried out sporadically over many years and as different extraction methods were used, comparisons of the results have been hampered. Therefore, in August/September 1986, 24 sites were sampled and evaluated using one quantitative method throughout. Sites range from mud to exposed sand and from the sublittoral to the supralittoral. Macrofauna and the taxa Plathelminthes, Polychaeta, and Oligochaeta are determined to species level. Macrofaunal (>0.5 mm) abundance is highest in mud and continuously decreases with increasing exposure to wave action. Meiofaunal (<0.5 mm) abundance is less variable. Nematoda dominate in mud and muddy sand, Copepoda in sheltered and exposed sand, other taxa only intermittently. Related to surface area, no correlation between macro-and meiofaunal abundance is apparent. Plathelminthes and Copepoda reach highest abundance per surface area in sand but their per volume density is higher in mud and muddy sand. Related to sediment volume instead of surface area, the meiofaunal abundance pattern is very similar to the macrofaunal pattern. The faunal composition changes gradually along the tidal gradient without general faunal boundaries. On an averange, the faunal similarity of neighbouring sites is highest in Oligochaeta and lowest in Plathelminthes. Presumably, Oligochaeta tolerate wider ranges of environmental factors. This may explain the low number of oligochaete species. On the other hand, Plathelminthes seem to adapt to relatively narrow ranges of factors and their species richness is highest. Because of macrofaunameiofauna interaction it is suggested that the meiofaunal assemblage will be least stable in mud and muddy sand, and most stable in exposed sand.

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

    PubMed Central

    2011-01-01

    Background As yet, few genomic resources have been developed in crustaceans. This lack is particularly evident in Copepoda, given the extraordinary numerical abundance, and taxonomic and ecological diversity of this group. Tigriopus californicus is ideally suited to serve as a genetic model copepod and has been the subject of extensive work in environmental stress and reproductive isolation. Accordingly, we set out to develop a broadly-useful panel of genetic markers and to construct a linkage map dense enough for quantitative trait locus detection in an interval mapping framework for T. californicus--a first for copepods. Results One hundred and ninety Single Nucleotide Polymorphisms (SNPs) were used to genotype our mapping population of 250 F2 larvae. We were able to construct a linkage map with an average intermarker distance of 1.8 cM, and a maximum intermarker distance of 10.3 cM. All markers were assembled into linkage groups, and the 12 linkage groups corresponded to the 12 known chromosomes of T. californicus. We estimate a total genome size of 401.0 cM, and a total coverage of 73.7%. Seventy five percent of the mapped markers were detected in 9 additional populations of T. californicus. Of available model arthropod genomes, we were able to show more colocalized pairs of homologues between T. californicus and the honeybee Apis mellifera, than expected by chance, suggesting preserved macrosynteny between Hymenoptera and Copepoda. Conclusions Our study provides an abundance of linked markers spanning all chromosomes. Many of these markers are also found in multiple populations of T. californicus, and in two other species in the genus. The genomic resource we have developed will enable mapping throughout the geographical range of this species and in closely related species. This linkage map will facilitate genome sequencing, mapping and assembly in an ecologically and taxonomically interesting group for which genomic resources are currently under development

  3. Changes of concentrations and possibility of accumulation of bisphenol A and alkylphenols, depending on biomass and composition, in zooplankton of the Southern Baltic (Gulf of Gdansk).

    PubMed

    Staniszewska, Marta; Nehring, Iga; Mudrak-Cegiołka, Stella

    2016-06-01

    The focus of the present study was to find the relationship between concentrations of bisphenol A (BPA), 4-tert-octylphenol (OP) and 4-nonylphenol (NP) in zooplankton and seasonal changes in the composition and biomass of particular zooplankton taxa in the Gulf of Gdansk (Southern Baltic) in the years 2011-2012. Assays of BPA, OP and NP in water and zooplankton samples were performed using the HPLC/FL system. High mean concentrations of the studied compounds, determined in spring (405.9 (BPA); 25.7 (OP); 111.2 (NP) ng g(-1) dw), can be linked to the high proportion of meroplankton in that season. Rotifera also had an influence on the rise in concentrations of the studied compounds but to a lesser degree, while the lowest concentrations (determined in summer) can be associated with the high participation of Copepoda and Cladocera in zooplankton biomass. It was also observed that juvenile forms can be more susceptible to accumulating endocrine disrupting compounds (EDCs). This is indicated by the positive correlation between BPA concentration in zooplankton and the proportion of Copepoda nauplii biomass in spring (r = 0.90; p < 0.05). In most cases, greater zooplankton biomass accumulated higher concentrations and loads of the studied compounds. With biomass growth (to 123.32 μg m(-3)), the bioconcentration factor also rose (to max 46.1·10(3)), demonstrating that unlike typical hydrophobic compounds the studied EDCs do not become "diluted" in zooplankton biomass. The highest BPA concentrations from all compounds may be connected with anthropogenic sources located in the coastal zone. PMID:26970874

  4. Ecology of the Atlantic black skipjack Euthynnus alletteratus (Osteichthyes: Scombridae) in the western Mediterranean Sea inferred by parasitological analysis.

    PubMed

    Mele, Salvatore; Pennino, M Grazia; Piras, M Cristina; Macías, David; Gómez-Vives, M José; Alemany, Francisco; Montero, Francisco E; Garippa, Giovanni; Merella, Paolo

    2016-09-01

    Between 2008 and 2011, the head of 150 Euthynnus alletteratus (Osteichthyes: Scombridae) caught inshore off the southeastern Iberian coast (western Mediterranean Sea) were examined for parasites. Two monogeneans, four didymozoid trematodes and four copepods were found. Parasite abundance showed a positive relationship with the annual sea surface temperature, except for Pseudocycnus appendiculatus, but negative with the sea depth (Capsala manteri, Neonematobothrium cf. kawakawa and Caligus bonito). Prevalences and mean abundances differed significantly among sampling areas, except for C. manteri, Oesophagocystis sp. 2 and Ceratocolax euthynni, and sampling years (Melanocystis cf. kawakawa, N.cf. kawakawa, P. appendiculatus and Unicolax collateralis). Results indicate that the parasite abundances of E. alletteratus in the western Mediterranean Sea depend mainly on regional environmental variables, which can show interannual variations. The presence of pelagic parasites, i.e. didymozoids and P. appendiculatus, could indicate that E. alletteratus migrates between inshore and offshore pelagic domains. The different parasite faunas reported in E. alletteratus populations from the western Atlantic Ocean and the Mediterranean Sea appear to point out the geographical host isolation. These results suggest that E. alletteratus inhabiting the western Mediterranean Sea performs inshore-offshore small-scale migrations, and not transoceanic migrations between the western Atlantic Ocean and Mediterranean Sea. PMID:27173779

  5. Notes on the husbandry and long-term transportation of Bull ray (Pteromylaeus bovinus) and Dolphinfish (Coryphaena hippurus and Coryphaena equiselis).

    PubMed

    Rodrigues, Nuno; Correia, João; Pinho, Rúben; Graça, José; Rodrigues, Filipe; Hirofumi, Morikawa

    2013-03-01

    Bull rays (Pteromylaeus bovinus) and Dolphinfish (Coryphaena hippurus and Coryphaena equiselis) were collected in Olhão (south of Portugal). These animals hosted multiple parasites, namely Caligus spp., and underwent a variety of treatments to remove them. Of all treatments tested, hydrogen peroxide showed the best results, although only concentrations above 100 ppm were effective in parasite removal. These high concentrations, however, proved to be highly toxic for the fish and led to the loss of some animals, especially those which had been handled before treatment. A total of 14 Bull rays were transported to Bolougne-Sur-Mer (France) by road and some animals were lost, which was attributed to excessive time in transit (>45 hr). In another transport, three Bull rays and 10 Dolphinfishes were moved to Stralsund (Germany) by road and air. The mechanical wounds suffered by one of the Bull rays during transport led to its death and, consequently, a deterioration of water quality in the tank containing two other conspecifics. This deterioration of water quality resulted in problems for the other two Bull rays, and one perished approximately 48 hr after arrival. The authors concluded that Dolphinfish can be transported with a low bioload for at least 27 hr, and Bull rays should not undergo transports longer than 35 hr. Special attention must be taken to injured animals, since this can lead to a decrease in water quality and consequently affect other animals in the same transport tank. PMID:23037944

  6. Richness, infestation and specificity of spinturnicid mites (Acari: Spinturnicidae) on bats in southern Oaxaca, Mexico.

    PubMed

    Colín-Martínez, Helisama; García-Estrada, Carlos

    2016-10-01

    Studies of mites on bats in the Mexican state Oaxaca are scarce. Our objective was therefore to evaluate the richness, infestation, and specificity of spinturnicid mites on bats in southern Oaxaca, Mexico. Bats were monthly captured from April 2010 to February 2011, in four sites using four mist-nets; also, we visited natural (crevices) and artificial roosts (tunnel). Of each bat we account the number of spinturnicid mites, considering the area of the body where they were collected. Mites were preserved in 70 % ethanol and later they were mounted on microscope slides in Hoyer's medium. We captured bats of 15 species, of which eight species were infested. We recorded seven spinturnicid mites: five of the genus Periglischrus, one of the genus Cameronieta, and one of the genus Mesoperiglischrus. Periglischrus caligus, P. iheringi, and Periglischrus sp. are new records on Artibeus lituratus, Glossophaga soricina, and G. commissarisi, respectively. More infested bat species were Artibeus jamaicensis (93.8 %), A. lituratus (88.9 %), G. commissarisi and Sturnira parvidens (both 66.7 %). Prevalence of A. jamaicensis and A. lituratus was significantly higher than most other bat species. Although prevalence percentage was high, mean and median intensity were low. Spinturnicid mites were recorded in particular areas of a bat's body; therefore, they could be an additional tool for the taxonomic identification of bats. PMID:27431824

  7. Zoo-heleoplankton structure in three artificial ponds of North-eastern Argentina.

    PubMed

    Frutos, S M; Carnevali, R

    2008-09-01

    The aim of the present study was to compare the abundance and species richness of zoo-heleoplankton bigger than 53 microm in an annual cycle under similar climate conditions in three artificial ponds, in order to observe the changes during an annual cycle. Samples were taken monthly from June 1993 to July 1994 in Corrientes, Argentina. The first pond (A) was covered an 80% by Eichhornia crassipes (Mart.), the second one (B) with bloom of Microcystis aeruginosa (Kurtzing) and the last one (C) with organic matter deposited in the bottom. The water was more acidic at pond A, and the water at pond B contained more dissolved oxygen concentration than the water at the other two ponds. The zoo-heleoplankton densities varied between 20-1728 ind.l(-1) at pond A, 42-4082 ind.l(-1) at pond B and 148-2447 ind.l(-1) at pond C. The maximum zoo-heleoplankton abundance was found in the pond with cyanobacteria bloom during Autumn 1994 and the minimum abundance was found in the one with a predominance of E. crassipes. The rank of species richness was pond A > pond B > pond C. Rotifera was the most abundant group in pond A whereas the larval stages of Copepoda were abundant in the other two ponds. Anuraeopsis navicula Rousselt 1910 was the dominant population in the pond with macrophytes prevalence. Brachionus calyciflorus Pallas 1776 and larval stage of Copepoda had variable proportions in the pond with cyanobacteria bloom. Thermocyclops decipiens (Kiefer 1929) was present during the annual cycle only in the pond with organic matter deposited in the bottom. The succession of taxa was observed in the pond with coverage of aquatic macrophytes and with cyanobacteria bloom. Differences in species richness and low similarity in zoo-heleoplankton between ponds were determined by differences in the quality of the water in relation to the presence of macrophytes, cyanobacteria, organic matter deposited in the bottom and fish predation. Multiple regression analysis (stepwise) revealed that

  8. The ice fauna in the shallow southwestern Beaufort Sea, Arctic Ocean

    NASA Astrophysics Data System (ADS)

    Carey, Andrew G.

    1992-06-01

    Sympagic fauna were studied in seasonal fast ice adjacent to Narwhal Island during the spring of 1979 and 1980, with emphasis on the origin of the fauna and its relationship to contiguous pelagic and benthic communities. The results of five subprojects are reviewed and compared with recent literature. Within Stefansson Sound, inshore of Narwhal Island, total sympagic meiofaunal densities and species diversity were low. In March 1979, the dominant taxa were polychaete larvae and crustacean nauplii, while in May the dominant group was Nematoda. Total numerical densities were low, ranging from 4500 to 8000 per m 2. During the spring of 1980 large numbers of invertebrate fauna concentrated at the undersurface of seasonal sea ice on the inner western Beaufort Sea continental shelf, seaward of Narwhal Island. The sympagic meiofauna were comprised primarily of benthic harpacticoid and cyclopoid copepods, turbellarians, nematode worms, and polychaete worm larvae. Total meiofaunal densities increased from about 6000 per m 2 in April to about 482,000 per m 2 in June. All life stages of Cyclopina gracilis (Copepoda: Cyclopoida) were present in the ice. This species appeared to reproduce continuously from early April to early June during the study period. The Harpacticus sp. (Copepoda: Harpaticoida) population consisted of one cohort whose individuals grew in size from April to early June. The sympagic macrofauna consisted entirely of amphipod crustaceans, primarily comprised of benthic species. Population size structure of the amphipod Pseudalibrotus (= Onisimus) litoralis was bimodal and there was a lack of intermediate growth stages. These characteristics indicate that this species has a two-year life cycle in the Beaufort Sea. The highest growth rate for P. litoralis coincided with maximal ice algal production. P. litoralis fed largely on meiofaunal Crustacea and amphipod fragments in April, but its diet switched to ice algae during the height of the bloom in late May

  9. Lipids in selected abyssal benthopelagic animals: links to the epipelagic zone?

    NASA Astrophysics Data System (ADS)

    Bühring, Solveig I.; Christiansen, Bernd

    A detailed study of the lipids of selected zooplankton species and scavenging amphipods in the near-bottom water layer (15-100 m above bottom, mab) was carried out at the BENGAL site in late summer 1998. Copepoda were the main contributors to the zooplankton, comprising 75% of the total abundance, followed by Ostracoda and Chaetognatha. Calanoid copepods of the family Metridinidae were predominant and accounted for more than 50% of all copepods. Two types of storage lipids were distinguished: triacylglycerols and wax esters. Ostracoda and the polychaete Vanadis sp. stored exclusively triacylglycerols whilst the bulk of the Copepoda accumulated wax esters, with the exception of the family Aetideidae. In the amphipods both lipid classes were found: Eurythenes gryllus stored wax esters and Paralicella spp. and Orchomene sp. triacylglycerols. The fatty acid composition was characterized by a high level of monounsaturated 18:1 ( n-9), which is described as characteristic for animals living in the deeper layers of the water column, and to a lesser degree by 16:1 ( n-7) and 20:5 ( n-3), which are typical components of diatom lipids, and 22:6 ( n-3), typical of dinoflagellates. The ratio of 18:1 ( n-9):18:1 ( n-7) fatty acids was between 5 and 10 in the copepods and indicates a carnivorous/omnivorous feeding behaviour in this group, whereas the higher ratios of 8-18 in the amphipods confirm their necrophagy. The fatty alcohols of the animals storing wax esters were dominated by the monounsaturated isomers 18:1 ( n-9) and 18:1 ( n-7). The predominance of wax esters as storage lipids in the deep-sea copepods indicates a strong seasonality in the availability of food. This is supported by the high levels of 16:1 ( n-7), 20:5 ( n-3) and 22:6 ( n-3) fatty acids, which point to there being a direct link between the surface primary production and deep-sea copepods, probably via the rapid deposition of phytodetritus.

  10. Community ecology of the metazoan parasites of freshwater fishes of Kerala.

    PubMed

    Beevi, M Razia; Radhakrishnan, S

    2012-10-01

    The prevalence and mean intensity of metazoan parasite infection, the community characteristics (richness index, dominance index, evenness index and Shannon index of diversity) and the qualitative similarity of the metazoan parasite fauna among the species and families of the fishes were determined of 13 fish species of freshwater fishes of Kerala belonging to seven families. The metazoan parasite fauna of this geographical area is very diverse; it consisted of 33 species of parasites belonging to seven major taxa: ten species of Monogenea, nine Digenea, two Cestoda, six Nematoda, three Acanthocephala, two Copepoda and one Isopoda. Prevalence of infection ranged from 32.9% (Puntius vittatus) to 87.1% (Mystus oculatus) and mean intensity from 3.8 (Puntius vittatus) to 27.6 (Aplocheilus lineatus). The infra- and component communities of parasites were somewhat characteristic. The dominance pattern of the major taxa was in the order Digenea > Nematoda > Monogenea = Acanthocephala > Cestoda = Copepoda > Isopoda. Macropodus cupanus harboured the richest fauna and Puntius vittatus had the least rich fauna. The parasite fauna of A. lineatus was the most heterogeneous and that of M. cavasius, the most homogeneous. The diversity of the parasite fauna was the greatest in M. cavasius and the least in A. lineatus. The parasite faunas of A. lineatus and M. cupanus and of M. cavasius and M. oculatus were similar. However, in spite of the taxonomic nearness and the similarity of the habits and habitats of the four species of cyprinids (P. amphibius, P. filamentosus, P. sarana and P. vittatus), their parasite fauna were qualitatively very dissimilar-of the seven species of parasites encountered in them only one was shared by the four host species. The cyprinid, Rasbora daniconius, had its own characteristic component community of parasites consisting of six species none of which was shared by the other four cyprinids. The richest parasite fauna was that of the family

  11. Lake Roosevelt Fisheries Evaluation Program, Part B; Limnology, Primary Production, and Zooplankton in Lake Roosevelt, Washington, 1998 Annual Report.

    SciTech Connect

    Shields, John; Spotts, Jim; Underwood, Keith

    2002-11-01

    of 1.5 m (5 ft) when compared with a 4.6 m (15 ft) depth, and during the shorter incubation periods (two and four weeks). Mean zooplankton densities were greatest for Copepoda (88 %), then Daphnia spp. (10%) and other Cladocera (2.1%), while the zooplankton biomass assessment indicated Daphnia spp. had the greatest biomass (53.6%), then Copepoda (44.0%) and other Cladocera (2.5%). Mean overall zooplankton densities were the lowest observed since 1991. The cause was unclear, but may have been an artifact of human error. It seems unlikely that hydro-operations played a significant part in the reduction of zooplankton in light of the relatively friendly water year of 1998.

  12. DNA Barcoding of Metazoan Zooplankton Copepods from South Korea

    PubMed Central

    Ryu, Shi Hyun; Kim, Sang Ki; Lee, Jin Hee; Lim, Young Jin; Lee, Jimin; Jun, Jumin; Kwak, Myounghai; Lee, Young-Sup; Hwang, Jae-Sam; Venmathi Maran, Balu Alagar; Chang, Cheon Young; Kim, Il-Hoi; Hwang, Ui Wook

    2016-01-01

    Copepods, small aquatic crustaceans, are the most abundant metazoan zooplankton and outnumber every other group of multicellular animals on earth. In spite of ecological and biological importance in aquatic environment, their morphological plasticity, originated from their various lifestyles and their incomparable capacity to adapt to a variety of environments, has made the identification of species challenging, even for expert taxonomists. Molecular approaches to species identification have allowed rapid detection, discrimination, and identification of cryptic or sibling species based on DNA sequence data. We examined sequence variation of a partial mitochondrial cytochrome C oxidase I gene (COI) from 133 copepod individuals collected from the Korean Peninsula, in order to identify and discriminate 94 copepod species covering six copepod orders of Calanoida, Cyclopoida, Harpacticoida, Monstrilloida, Poecilostomatoida and Siphonostomatoida. The results showed that there exists a clear gap with ca. 20 fold difference between the averages of within-specific sequence divergence (2.42%) and that of between-specific sequence divergence (42.79%) in COI, suggesting the plausible utility of this gene in delimitating copepod species. The results showed, with the COI barcoding data among 94 copepod species, that a copepod species could be distinguished from the others very clearly, only with four exceptions as followings: Mesocyclops dissimilis–Mesocyclops pehpeiensis (0.26% K2P distance in percent) and Oithona davisae–Oithona similis (1.1%) in Cyclopoida, Ostrincola japonica–Pseudomyicola spinosus (1.5%) in Poecilostomatoida, and Hatschekia japonica–Caligus quadratus (5.2%) in Siphonostomatoida. Thus, it strongly indicated that COI may be a useful tool in identifying various copepod species and make an initial progress toward the construction of a comprehensive DNA barcode database for copepods inhabiting the Korean Peninsula. PMID:27383475

  13. Community ecology of the metazoan parasites of Atlantic moonfish, Selene setapinnis (Osteichthyes: Carangidae) from the coastal zone of the State of Rio de Janeiro, Brazil.

    PubMed

    Cordeiro, A S; Luque, J L

    2004-08-01

    Eighty-nine specimens of Selene setapinnis (Mitchill, 1815) collected from the coastal zone of the State of Rio de Janeiro (21-23 degrees S, 41-45 degrees W and 23 degrees 05'S, 44 degrees 30'W), Brazil, from August 2001 to May 2002, were necropsied to study their metazoan parasites. Eighty-one (91%) specimens of S. setapinnis were parasitized by one or more metazoan species. Twenty-one species of parasites were collected: 8 digeneans, 3 monogeneans, 2 cestodes, 5 nematodes, and 3 copepods. The endoparasites (digeneans, cestodes, and nematodes) were 74.1% of total number of parasite specimens collected. The monogenean Pseudomazocraes selene (Hargis, 1957) was the most dominant species with the highest prevalence in the parasite community of S. setapinnis. The metazoan parasites of this host species showed the typical aggregated pattern of distribution. Only one parasite species (Acanthocolpoides pauloi Travassos, Freitas & Buhrnheim, 1955) showed positive correlation between the host total length and parasite abundance in S. setapinnis. Caligus robustus Bassett-Smith, 1898, P. selene, and Terranova sp. demonstrated positive correlation between the host total length and prevalence. Larvae of Terranova sp. showed influence of the host sex on its prevalence. A pair of ectoparasite species, P. selene-C. robustus, exhibited positive covariation between their abundances. Two pairs of endoparasite species, L. microstomum-P. merus and A. pauloi-P. merus showed significant covariation among their abundances; and the pair Terranova sp.-Raphidascaris sp. had positive co-ocorrence and covariation in the infracommunities of S. setapinnis. Like the parasite communities of the other carangid fishes from Rio de Janeiro, the parasite community of S. setapinnis is apparently only a slightly ordered species complex, characterized by dominance of endoparasite species. PMID:15622838

  14. Influence of season and site location on European cultured sea bass parasites in Corsican fish farms using indicator species analysis (IndVal).

    PubMed

    Antonelli, Laetitia; Foata, Joséphine; Quilichini, Yann; Marchand, Bernard

    2016-02-01

    The parasites of 536 European sea bass, Dicentrarchus labrax, were studied between January 2012 and December 2013 in six Corsican fish farms. The indicator value (IndVal) method, which combines measures of fidelity and specificity, has been used in this study. Because of its resilience to changes in abundance, IndVal is a particularly effective tool for ecological bioindicator. The IndVal method showed how season can influence the occurrence of parasite species in cultured sea bass and also identified parasites as bioindicators relative to fish farm location. The combination of specificity and fidelity highlighted several parasite species as significant indicators. A randomization test identified five parasite species as having a significant indicator value for season (the monogenean Diplectanum aequans; the copepods Lernanthropus kroyeri and Caligus minimus; the isopod Ceratothoa oestroides, and the myxosporidian Ceratomyxa labracis). If gills parasites are compared, they can be seen to be indicator species for two different seasons. The only Monogenea species D. aequans had fidelity and specificity more pronounced in winter, whereas both copepod species and the Isopoda revealed highest rates of infestation corresponding with an increase of water temperature. Four species have a significant indicator value for site location (D. aequans, L. kroyeri, C. minimus, and C. oestroides). The fact that the farm 6 was isolated on the east coast of Corsica may not have allowed the parasite to infect other farms. The presence of copepods on a single farm can also be explained according to salinity variations. Data for species composition and infection levels should help to improve the monitoring and management of parasitism in cultured sea bass populations. PMID:26446088

  15. Technical note: Modifying Atlantic salmon (Salmo salar) jumping behavior to facilitate innovation of parasitic sea lice control techniques.

    PubMed

    Dempster, T; Kristiansen, T S; Korsøen, Ø J; Fosseidengen, J E; Oppedal, F

    2011-12-01

    Industrial salmon farms are reservoirs of parasitic sea lice (Lepeophtheirus salmonis and Caligus spp.), which causes both production inefficiencies and contributes to population-level declines of wild salmon and trout. Current control methods vary in effect and stimulate controversy by the discharge of chemicals into the environment. An alternate control method uses a thin, chemical-infused oil layer on the sea surface. As farmed salmon jump through the surface, the treatment makes contact with the lipophilic carapace of sea lice and kills them. To enhance the effectiveness of this method, we tested whether the natural jumping behavior of salmon could be increased and directed. In a 2,000-m(3) experimental sea-cage, we removed the ability of groups of salmon to access the surface for different periods (0 to 48 h) and measured their surface behaviors after the surface became accessible again. Surface removal for 24 and 48 h induced 93% of salmon to jump in the 2 h after surface access was reinstated, a result that differed (P < 0.001) from the shorter duration (0 to 12 h) treatments. Salmon without surface access for 24 and 48 h jumped 2 to 3 times more often (P < 0.001), and made their first jump 2 to 3 times sooner (P = 0.003) on average after surface access became available than salmon in the shorter duration treatments. Our results indicate that removal of surface access for short periods may lead to loss of air from the physostomous swim bladder and cause negative buoyancy. This creates a behavioral drive for salmon to jump, swallow air and fill their swim bladders once surface access is reinstated. By combining the increased jumping behavior induced by this technique with a floating, oil-infused treatment, efficiency of sea lice treatments may be improved and treatment chemicals can be re-collected, thus decreasing environmental pollution. PMID:21821806

  16. Metazoan gill parasites of the Atlantic bluefin tuna Thunnus thynnus (Linnaeus) (Osteichthyes: Scombridae) from the Mediterranean and their possible use as biological tags.

    PubMed

    Culurgioni, Jacopo; Mele, Salvatore; Merella, Paolo; Addis, Piero; Figus, Vincenza; Cau, Angelo; Karakulak, Firdes Saadet; Garippa, Giovanni

    2014-04-01

    The gills of 63 specimens of the Atlantic bluefin tuna Thunnus thynnus (Linnaeus) (Osteichthyes: Scombridae) from three localities of the Mediterranean (Sardinian, Tyrrhenian and Levantine Seas) were examined for metazoan parasites. The parasite fauna of T. thynnus from the Sea of Sardinia included 11 species: five didymozoid trematodes, three capsalid and one hexostomid monogeneans, and one caligid and one pseudocycnid copepods. Four didymozoids were found in fish from the Levantine Sea and only one didymozoid was recorded in fish from the Tyrrhenian Sea. Dividing the hosts into four size-groups (small, medium-sized, large and extra large), the pairwise comparison of prevalence and mean abundance of the new and literary data) showed differences according to host size. The differences in the composition of the parasitic faunas and in the prevalence of parasites, observed between the small tunas from the Tyrrhenian Sea and the medium-sized tunas from the Adriatic Sea, Levantine Sea and the North-East (NE) Atlantic Ocean, indicated that these groups form discrete units. The parasite fauna of the large tunas from the Sea of Sardinia is the richest among the bluefin tuna populations of the Mediterranean and the NE Atlantic, due to the presence of species not found elsewhere in bluefin tunas, such as Caligus coryphaenae Steenstrup et Lütken, 1861, Capsala magronum (Ishii, 1936) and C. paucispinosa (Mamaev, 1968). This fact and the prevalence of some parasites of this group (lower than those of medium-sized fish from the NE Atlantic and higher than the small and medium-sized tunas from the Mediterranean) suggest that the large-sized tuna group in the western Mediterranean is formed by Mediterranean resident tunas (poorly infected), and by tunas migrating from the Atlantic Ocean (heavily infected). PMID:24822321

  17. Three new records of copepods (Siphonostomatoida) parasitic on marine fishes of Iraq, including the relegation of two species of Lernanthropinus to Lernanthropinus temminckii (von Nordmann, 1864).

    PubMed

    Venmathi Maran, B A; Moon, Seong Yong; Adday, Thamir Katea; Khamees, Najim Rijab; Myoung, Jung-Goo

    2014-03-01

    Three parasitic copepods (Siphonostomatoida) belonging to three different genera were recovered from marine fishes of Iraq, and are listed here as new records. The sea lice Caligus epinepheli Yamaguti, 1936 (Caligidae) was collected from the Japanese threadfin bream, Nemipterus japonicus (Bloch). It had been frequently reported from teleost fishes around the world. The second record, comprising male and female, was another caligid, rarely caught from fishes - Hermilius longicornis Bassett-Smith, 1898, collected from the giant catfish, Netuma thalassina (Rüppell). This paper features the first description of the male of the latter species. The third record was the lernanthropid, Lernanthropinus temminckii (von Nordmann, 1864) (Lernanthropidae), redescribed based on the specimens collected from the greater lizard fish, Saurida tumbil (Bloch) (Synodontidae). In order to clarify its taxonomic status, our specimen was compared with the holotype of L. gibbosus (Pillai, 1964) from the collections of Zoological Survey of India, Kolkata, and the syntypes of L. sauridae Do in Ho and Do, 1985 and L. temminckii from the collections of the Smithsonian Institution, Washington D.C. We found similarities in the morphology of the body, mouthparts, and legs 1-4 in three above-mentioned species. The prominent feature, the setation pattern of legs 1 and 2 was similar in all the female specimens examined. In the light of this, we formally relegate L. gibbosus and L. sauridae to synonymy with L. temminckii. Another important similarity is that Lernanthropinus gibbosus, L. sauridae, and L. temminckii have exclusively been parasitic on lizardfishes (Synodontidae). The attachment site of all three copepods reported form Iraq were the gill filaments. PMID:24570061

  18. Morphometric, molecular and ecological analyses of the parasites of the sharpsnout seabream Diplodus puntazzo Cetti (Sparidae) from the Spanish Mediterranean: implications for aquaculture.

    PubMed

    Sánchez-García, N; Ahuir-Baraja, A E; Raga, J A; Montero, F E

    2015-03-01

    One of the fish species with the highest potential for aquaculture is the sharpsnout seabream, Diplodus puntazzo Cetti. Among other aspects, the development of new fish cultures requires studies of potential pathogens that may compromise survival of the fish in captivity. Moreover, both cultured and wild fish can act as sources or reservoirs of pathogens which may negatively affect other well-established cultures. We have studied the parasite fauna of the wild sharpsnout seabream, and monitored the survival of the parasites in culture conditions. The sharpsnout seabream was sampled from two different Spanish localities and examined for parasites. Additionally, 20 fish were maintained in captivity. Ten of them were examined for parasites after a period of 10 days and a further ten fish after another 10 days. All fish were parasitized with at least four species, with 19 parasite species being identified, seven of which were recorded for the first time in the sharpsnout seabream. These included Microcotyle sp., Magnibursatus bartolii, Steringotrema pagelli, Galactosomum sp., Cardiocephaloides longicollis, Caligus ligusticus and Gnathia vorax. We also report the first records of two parasite species in the wild sharpsnout seabream, the polyopisthocotylean monogeneans Atrispinum seminalis and Sparicotyle chrysophrii. Previously, these parasites had only been recorded in farmed sharpsnout seabream. Most parasites in the skin, gills and alimentary tract disappeared under the conditions of captivity, with the exception of the monogeneans of the genus Lamellodiscus. The information provided about the sharpsnout seabream parasite fauna will be useful to prevent possible problems in fish farms due to some parasite species. Many parasites of the sharpsnout seabream recorded in the present study are shared by the main fish species in Mediterranean aquaculture, the gilthead seabream, thus suggesting the possibility of cross-infections. PMID:24299967

  19. Two new stygobiotic copepod species from the Tibesti area (Northern Chad) and a re-description of Pilocamptus schroederi (van Douwe, 1915).

    PubMed

    Brancelj, Anton

    2015-01-01

    Between 4th and 18th March 2014, an international group of biologists carried out a hydrobiological expedition to the Ounianga-Tibesti area of northern Chad (Africa). The Tibesti is a desert volcanic area, intersected by the beds of ancient rivers which were active in the Tertiary. In deep canyons there are small water bodies (gueltas/aguelmans), fed by rain and spring water. They are rich in zooplankton, benthos, and even fish, but their groundwater fauna has previously been unknown. Groundwater samples collected in the vicinity of one guelta contained Syncarida, Isopoda, and Copepoda. Among the latter, two new species were recognised, Haplocyclops (H.) henrii sp. nov. and Parastenocaris joi sp. nov., together with a third species, Pilocamptus schroederi (van Douwe, 1915), previously known only from the littoral zone and wet mosses of Lake Victoria. The Tibesti area is thus the third known location of P. schroederi. All these species have a Gondwanaland distribution and are probably relicts of the Tertiary fauna, formerly widespread in the Sahara. Together with descriptions of two new species, a detailed re-description of P. schroederi is presented, along with remarks on their ecology. PMID:26250289

  20. Population dynamics of the ctenophore Mnemiopsis leidyi and its impact on the zooplankton in the coastal regions of the Black Sea of the Crimean coast in 2004-2008

    NASA Astrophysics Data System (ADS)

    Finenko, G. A.; Abolmasova, G. I.; Romanova, Z. A.; Datsyk, N. A.; Anninskii, B. E.

    2013-02-01

    The abundance, biomasses, and population structure of the ctenophore Mnemiopsis leidyi were monitored in the coastal waters of the northern part of the Black Sea (Sevastopol Bay and the adjacent continental shelf regions) in 2004-2008. The abundance and species composition of the comb jelly's food in the sea were obtained along with experimental data on the digestion time. Based upon these data, the feeding intensity of the ctenophore in situ was estimated. This information was used to calculate the predatory impact of the comb jelly population on certain groups of forage organisms and the forage zooplankton community as a whole. The predatory impact of the M. leidyi population on the bivalve veligers was the highest (up to 90% of the abundance a day) compared to the Copepoda and Cladocera (30% and 40%, respectively). In the summers of 2004-2008, the daily consumption rates of the zooplankton by the ctenophore population in the shelf zone and in the bay were similar to each other: up to 15% and 12% of the abundance a day, respectively. The highest pressure of the ctenophore upon the zooplankton was observed in 2004 and 2008, when M. leidyi was especially abundant in the plankton for a long time.

  1. Food of forage fishes in western Lake Erie, 1975-76

    USGS Publications Warehouse

    Muth, Kenneth M.; Busch, Wolf-Dieter N.

    1989-01-01

    In western Lake Erie in the summer and fall of 1975–1976, food eaten by seven forage fishes—emerald shiner (Notropis atherinoides), spottail shiner (Notropis hudsonius), trout-perch (Percopsis omiscomaycus), andyoung-of-the-year (YOY) of alewife (Alosa pseudoharengus), gizzard shad (Dorosoma cepedianum), white bass (Morone chrysops), and freshwater drum (Aplodi-notus grunniens)—was divided among six major taxa: Cladocera, Copepoda, Diptera, Ostracoda, Amphipoda, and Algae. In addition, fish were eaten by YOY white bass, and Rotifera were consumed by YOY gizzard shad. Interspecies diet overlap indices, calculated to compare the food of the different species and to evaluate diet similarities, were usually highest for YOY white bass and YOY freshwater drum when compared with the other species and usually lowest between emerald shiners and all other forage fishes. Understanding the feeding interactions among fishes that could influence production at the forage-food level of the food web could provide insight into how cascading trophic interactions influence the production of piscivorous predators.

  2. Food of young-of-the-year lake trout (Salvelinus namaycush) in Presque Isle Harbor, Lake Superior

    USGS Publications Warehouse

    Swedberg, Donald V.; Peck, James W.

    1984-01-01

    The food habits of young lake trout (Salvelinus namaycush) were studied by examining the digestive tracts of 293 young-of-the-year collected in Presque Isle Harbor, Lake Superior. Lake trout in the 25 to 27-mm length range started to eat food organisms before all of their yolk material was absorbed. Organisms consumed by the 25 to 27-mm young-of-the-year included Chironomidae, Copepoda (Harpacticoida, Calanoida, Cyclopoida), and Cladocerea (Daphnia spp., Bosmina sp., Chydorus sp.). Chironomid pupae and chironomid larvae accounted for 74% and 5%, respectively, of the total volume of food eaten by the young lake trout in Presque Isle Harbor. Although copepods, cladocerans, and mysids were present in many stomachs, their contribution to the total volume of food was only 15%. Some lake trout in the 32 to 54-mm length range had consumed fry of sculpin (Cottus spp.) or rainbow smelt (Osmerus mordax), but the overall contribution of fish fry to the total volume of food was only 4% (frequency of occurrence, 10%). The lake trout in Presque Isle Harbor fed heavily on planktonic organisms, sparingly on benthic organisms, and were opportunistic feeders that appeared to prey on whatever forage organisms were available in the shallow nearshore waters.

  3. Norwegian deep-water coral reefs: cultivation and molecular analysis of planktonic microbial communities.

    PubMed

    Jensen, Sigmund; Lynch, Michael D J; Ray, Jessica L; Neufeld, Josh D; Hovland, Martin

    2015-10-01

    Deep-sea coral reefs do not receive sunlight and depend on plankton. Little is known about the plankton composition at such reefs, even though they constitute habitats for many invertebrates and fish. We investigated plankton communities from three reefs at 260-350 m depth at hydrocarbon fields off the mid-Norwegian coast using a combination of cultivation and small subunit (SSU) rRNA gene and transcript sequencing. Eight months incubations of a reef water sample with minimal medium, supplemented with carbon dioxide and gaseous alkanes at in situ-like conditions, enabled isolation of mostly Alphaproteobacteria (Sulfitobacter, Loktanella), Gammaproteobacteria (Colwellia) and Flavobacteria (Polaribacter). The relative abundance of isolates in the original sample ranged from ∼ 0.01% to 0.80%. Comparisons of bacterial SSU sequences from filtered plankton of reef and non-reef control samples indicated high abundance and metabolic activity of primarily Alphaproteobacteria (SAR11 Ia), Gammaproteobacteria (ARCTIC96BD-19), but also of Deltaproteobacteria (Nitrospina, SAR324). Eukaryote SSU sequences indicated metabolically active microalgae and animals, including codfish, at the reef sites. The plankton community composition varied between reefs and differed between DNA and RNA assessments. Over 5000 operational taxonomic units were detected, some indicators of reef sites (e.g. Flavobacteria, Cercozoa, Demospongiae) and some more active at reef sites (e.g. Gammaproteobacteria, Ciliophora, Copepoda). PMID:24911121

  4. Variability of invertebrate abundance in drinking water distribution systems in the Netherlands in relation to biostability and sediment volumes.

    PubMed

    van Lieverloo, J Hein M; Hoogenboezem, Wim; Veenendaal, Gerrit; van der Kooij, Dick

    2012-10-15

    A survey of invertebrates in drinking water from treatment works, internal taps and hydrants on mains was carried out by almost all water companies in the Netherlands from September 1993 to August 1995. Aquatic sow bugs (Asellidae, 1-12 mm) and oligochaeta worms (Oligochaeta, 1-100 mm), both known to have caused rare though embarrassing consumer complaints, were found to form 98% of the mean biomass in water flushed from mains. Their numbers in the mains water ranged up to 1500 (mean 37) Asellidae m(-3) and up to 9900 (mean 135) Oligochaeta m(-3). Smaller crustaceans (0.5-2 mm) dominated the numbers in water from mains. e.g. water fleas (Cladocera and Copepoda up to 14,000 m(-3)). Common invertebrates in treated water and in tap water were Rotifera (<1 mm) and nematode worms (Nematoda, <2 mm). No Asellidae, large Oligochaeta (>5 mm) or other large invertebrates were found in 1560 samples of 200 l treated water or tap water. Large variations in invertebrate abundance were found within and between distribution systems. Of the variability of mean biomass in mains per system, 55%, 60% and 63% could statistically be explained by differences in the Biofilm Formation Rate, non-particulate organic matter and the permanganate index of the treated water of the treatment works respectively. A similar correlation was found between mean invertebrate biomass and mean sediment volumes in the distribution systems (R(2) = 52%). PMID:22840474

  5. Response of aquatic invertebrates to ecological rehabilitation of Southeastern USA depressional wetlands.

    SciTech Connect

    Batzer, Donald P.; Taylor, Barbera E.

    2015-07-02

    Abstract We assessed aquatic invertebrate response to ecological rehabilitation treatment in 20 depression wetlands on the Savannah River Site, South Carolina, USA. All wetlands had been ditched for 50+ years. Sixteen of the 20 wetlands received rehabilitation treatment, and four wetlands remained untreated as a control group. Treatment included logging of all trees, plugging drainage ditches, and planting wetland trees and grasses. Hydroperiods were consequently extended in most of the treatment wetlands. As part a larger study, we sampled macroinvertebrates and microcrustaceans during the pre-habilitation (1998–2000) and rehabilitation (2001–2003) phases. Our study spanned 2 years of high rainfall (1998 and 2003) and 4 years of low rainfall (1999–2002). Samples were collected bimonthly from any wetlands holding water. Macroinvertebrate assemblages in treatment wetlands in 2003 had changed from previous years (1998–2002) and compared to control wetlands (1998–2003), with abundances of Baetidae, Coenagrionidae, Dytiscidae, Chironomidae, and Chaoboridae driving variation. For microcrustaceans (Copepoda and Branchiopoda, including Cladocera, Anostraca and Laevicaudata), assemblage composition and species richness responded mainly to hydrologic conditions. Rehabilitation efforts in these wetlands induced diverse and abundant invertebrate communities to develop, but some responses appeared opportunistic; several taxa that benefitted were not typical residents of depressional wetlands in the region.

  6. UV radiation and freshwater zooplankton: damage, protection and recovery

    PubMed Central

    Rautio, Milla; Tartarotti, Barbara

    2011-01-01

    While many laboratory and field studies show that zooplankton are negatively affected when exposed to high intensities of ultraviolet radiation (UVR), most studies also indicate that zooplankton are well adapted to cope with large variations in their UVR exposure in the pelagic zone of lakes. The response mechanisms of zooplankton are diverse and efficient and may explain the success and richness of freshwater zooplankton in optically variable waters. While no single behavioural or physiological protection mechanism seems to be superior, and while several unexplained and contradictory patterns exist in zooplankton UVR ecology, recent increases in our understanding are consistent with UVR playing an important role for zooplankton. This review examines the variability in freshwater zooplankton responses to UVR, with a focus on crustacean zooplankton (Cladocera and Copepoda). We present an overview of UVR-induced damages, and the protection and recovery mechanisms freshwater zooplankton use when exposed to UVR. We review the current knowledge of UVR impact on freshwater zooplankton at species and community levels, and discuss briefly how global change over the last three decades has influenced the UVR milieu in lakes. PMID:21516254

  7. Parental exposure to elevated pCO2 influences the reproductive success of copepods

    PubMed Central

    Cripps, Gemma; Lindeque, Penelope; Flynn, Kevin

    2014-01-01

    Substantial variations are reported for egg production and hatching rates of copepods exposed to elevated carbon dioxide concentrations (pCO2). One possible explanation, as found in other marine taxa, is that prior parental exposure to elevated pCO2 (and/or decreased pH) affects reproductive performance. Previous studies have adopted two distinct approaches, either (1) expose male and female copepoda to the test pCO2/pH scenarios, or (2) solely expose egg-laying females to the tests. Although the former approach is more realistic, the majority of studies have used the latter approach. Here, we investigated the variation in egg production and hatching success of Acartia tonsa between these two experimental designs, across five different pCO2 concentrations (385–6000 µatm pCO2). In addition, to determine the effect of pCO2 on the hatching success with no prior parental exposure, eggs produced and fertilized under ambient conditions were also exposed to these pCO2 scenarios. Significant variations were found between experimental designs, with approach (1) resulting in higher impacts; here >20% difference was seen in hatching success between experiments at 1000 µatm pCO2 scenarios (2100 year scenario), and >85% at 6000 µatm pCO2. This study highlights the potential to misrepresent the reproductive response of a species to elevated pCO2 dependent on parental exposure. PMID:25221371

  8. Zooplankton abundance, biovolume and size spectra at western boundary currents in the subtropical North Pacific during winter 2012

    NASA Astrophysics Data System (ADS)

    Dai, Luping; Li, Chaolun; Yang, Guang; Sun, Xiaoxia

    2016-03-01

    Horizontal changes in mesozooplankton abundance, biovolume and size spectra at western boundary currents in the subtropical North Pacific during winter 2012 were evaluated by ZooScan measurement on samples collected by net towing from 23 stations. Zooplankton abundance and biovolume ranged from 35.1 to 456.8 ind. m- 3 and 4.3 to 231.7 mm3 m- 3, respectively. Copepoda were the most dominant species, followed by Chaetognatha and Tunicata. According to the Bray-Curtis cluster analysis based on biovolume of zooplankton size classes of each taxonomic group at intervals of 1 (log2 mm3 ind.- 1) between - 6 and 12 and considering the effect of regional factors, zooplankton communities were classified into four groups, which basically coincided with the geographical patterns of different currents: the North Equatorial Current (NEC), the North Equatorial Counter Current (NECC), the Kuroshio Current (KC), and the Mindanao Eddy (ME), respectively. The largest and lowest biovolumes were observed in the NECC region and the NEC region, respectively, and both were dominated by the 0.3 to 1 mm equivalent spherical diameter (ESD) size class, while the ME region was dominant by the 1 to 2 mm ESD size class. The slopes of the normalized biovolume size spectra for each group were slightly lower than - 1 (range from - 0.85 to - 0.92), which indicates that zooplankton communities in the study area were characterized by low productivity and high energy transfer efficiency.

  9. Human-mediated dispersal of aquatic invertebrates with waterproof footwear.

    PubMed

    Valls, Luis; Castillo-Escrivà, Andreu; Mesquita-Joanes, Francesc; Armengol, Xavier

    2016-02-01

    Human-mediated dispersal has rarely been considered in wetland conservation strategies at regional scales, yet high concern exists about this aspect for (inter-)national management considering invasive species in other aquatic systems. In this context, we aim at understanding the role of human-mediated dispersal by footwear in protected wetlands with high conservation value. Zooplankton and zoobenthos were sampled in 13 shallow lakes in central Spain and, at the same time, mud attached to waders was collected and later cultured in deionized water under laboratory conditions for 4 weeks. Two-hundred and four individuals belonging to 19 invertebrate taxa were recovered after hatching; Ostracoda (84 %), Cladocera (53 %), Copepoda (30 %), Anostraca (30 %), and Notostraca (7 %) were the most frequent groups among the hatched crustaceans. NMDS and PERMANOVA analyses showed significant differences between the dispersed (via footwear) and the source active metacommunity, suggesting different dispersal abilities among the species found. Human vectors facilitate dispersal among protected lakes, which could eventuality lead to biotic homogenization and faster spread of non-indigenous species. Preservation strategies and education campaigns associated to target humans in close contact with water bodies should be imperative in conservation management of protected lakes. PMID:26216143

  10. Determining Microeukaryotic Plankton Community around Xiamen Island, Southeast China, Using Illumina MiSeq and PCR-DGGE Techniques.

    PubMed

    Yu, Lingyu; Zhang, Wenjing; Liu, Lemian; Yang, Jun

    2015-01-01

    Microeukaryotic plankton are important components of aquatic environments and play key roles in marine microbial food webs; however, little is known about their genetic diversity in subtropical offshore areas. Here we examined the community composition and genetic diversity of the microeukaryotic plankton in Xiamen offshore water by PCR-DGGE (polymerase chain reaction-denaturing gradient gel electrophoresis), clone-based sequencing and Illumina based sequencing. The Illumina MiSeq sequencing revealed a much (approximately two orders of magnitude) higher species richness of the microeukaryotic community than DGGE, but there were no significant difference in species richness and diversity among the northern, eastern, southern or western stations based on both methods. In this study, Copepoda, Ciliophora, Chlorophyta, Dinophyceae, Cryptophyta and Bacillariophyta (diatoms) were the dominant groups even though diatoms were not detected by DGGE. Our Illumina based results indicated that two northern communities (sites N2 and N3) were significantly different from others in having more protozoa and fewer diatoms. Redundancy analysis (RDA) showed that both temperature and salinity were the significant environmental factors influencing dominant species communities, whereas the full microeukaryotic community appeared to be affected by a complex of environmental factors. Our results suggested that extensive sampling combined with more deep sequencing are needed to obtain the complete diversity of the microeukaryotic community, and different diversity patterns for both abundant and rare taxa may be important in evaluating the marine ecosystem health. PMID:26020532

  11. Vorticity and mixing induced by the barotropic M 2 tidal current and zooplankton biomass distribution in the Gulf of California

    NASA Astrophysics Data System (ADS)

    Salas-de-León, David Alberto; Carbajal, Noel; Monreal-Gómez, Maria Adela; Gil-Zurita, Antonio

    2011-08-01

    Vertical mixing and biological processes in the Gulf of California were analyzed using calculated relative vorticity fields induced by the barotropic M 2 tide and zooplankton biomass distribution. M 2 tidal currents contribute significantly to the general circulation observed in the upper gulf. The results revealed zones with high vertical and horizontal values of relative vorticity in regions where temperature anomalies and water exchange take place. The horizontal component of the vorticity vector is considerable in areas of the upper gulf, where high vertical shear of the velocity was estimated. Patterns of the horizontal component of the vorticity, the Simpson-Hunter criterion and the chlorophyll concentration showed similarities. The interaction of tidal flow with the complex bathymetry is the main source of vorticity and mixing in the gulf. The vertical component of the relative vorticity reaches positive values in regions where cyclonic circulation has been reported. A total of 35 groups of zooplankton were identified in the gulf; Copepoda, Chaetognatha, and Euphausiacea were the three major groups. High zooplankton biomasses in the archipelago region of the gulf were associated with topographic effect, which induces strong shear velocities, creating vertical mixing and increasing the supply of nutrients to the surface layers, which in turn induces high chlorophyll concentration or phytoplankton and thereby supports the zooplankton biomass. The zooplankton biomass was closely related to high values of the horizontal component of relative vorticity.

  12. Epipelagic mesozooplankton succession and community structure over a marine ouffall area in the northeastern South China Sea.

    PubMed

    Tseng, Li Chun; Kumar, Ram; Dahms, Hans Uwe; Chen, Chun Te; Chen, Qing Chao; Hwang, Jiang Shiou

    2008-05-01

    This study analyses distribution and abundance patterns of mesozooplankton communities at 13 stations in the coastal waters over a marine outfall area in the northeastern South China Sea. Cruises were conducted in March, June and September 2002, and plankton samples were collected with a 333 microm North Pacific net. The Mesozooplankton was dominated by calanoid Copepods, Cladocera, Chaetognatha and Pteropoda. Stations located near the entrance of the harbor provided a relatively higher abundance of Noctilucales and Radiolarians. In total, 20 zooplankton groups were identified in which, Calanoida, Cladocera, Chaetognatha, Pteropoda, Poecilostomatoida and Appendicularia comprised 92.77% of the total zooplankton abundance. Copepoda dominated in all three cruises, comprising 65.32% of the total mesozooplankton abundance. Samples collected in June recorded higher mesozooplankton abundance than March and September samples. Onshore stations recorded higher BOD values, higher abundance of Noctilucales and Radiolarians and a relativelylower abundance of the overall mesozooplankton. Total mesozooplankton abundance did not correlate significantly with temperature, pH, or dissolved oxygen, but correlated negatively with BOD. PMID:18972677

  13. Mobile epifauna on Zostera marina, and infauna of its inflorescences

    NASA Astrophysics Data System (ADS)

    Hellwig-Armonies, Monika

    1988-06-01

    The faunal colonization of the leaves and inflorescences of intertidal Zostera marina L. and of the ambient water has been studied at the Island of Sylt (North Sea). The abundance of the snail Littorina littorea L. and the isopod Jaera albifrons Leach correlates significantly with leaf surface area. This is not the case with the abundance of meiofaunal Plathelminthes, Nematoda, Copepoda, and Polychaeta. However, they increase significantly with the numbers of generative shoots in the sampled seagrass bunches. Members of these taxa inhabit the Zostera inflorescences, and average abundance increases with the degree of decay of inflorescences. This temporary microhabitat presumably offers food and shelter. Copepods and ostracods dominate in the ambient water. Planktonic calanoid copepods correlate with the amount of sampled seawater, while Ostracoda correlate with the amount of resuspended detritus suggesting that they were resuspended themselves. The study shows that some meiofaunal taxa can rapidly exploit a short-lived habitat such as the Zostera inflorescences. Juvenile polychaetes use inflorescences as a nursery.

  14. Meiobenthos assemblages in the mekong estuarine system with special focus on free-living marine nematodes

    NASA Astrophysics Data System (ADS)

    Quang, Ngo Xuan; Vanreusel, Ann; Smol, Nic; Chau, Nguyen Ngoc

    2010-12-01

    Meiobenthos assemblages in eight estuaries of the Mekong river system were investigated in August 2008 (from the Cua Tieu estuary to the Tran De estuary). In each estuary, one sampling station was established for meiobenthos sampling. Twelve major taxa of meiobenthos were recorded in this estuarine system, including Nematoda, Copepoda, Turbellaria, Polychaeta, Oligochaeta, Tardigrada, Bivalvia, Ostracoda, Amphipoda, Cumacea, Gastrotricha, Gastropoda, and Crustacean Nauplii larvae. The densities of the meiobenthos range from 581 to 3168 inds/10 cm2. Nematodes always occupy the highest numbers with a percentage ranging from 64-99%. There are 135 nematode genera recorded in this study with the following as dominant genera Desmodora, Leptolaimus, Halalaimus, Thalassomonhystera, Theristus, Daptonema, Rhynchonema, Parodontophora, and Oncholaimus. Although the biodiversity of the meiobenthos at higher taxa level is not high compared to other marine environments, the estimates of nematode biodiversity at the genus level indicates high values. The increase in number of genera with increasing sampling intensity illustrate that the diversity is underestimated and would have been higher if the authors had considered a larger number of individuals, more replicates per station, and more sampling stations.

  15. Free-living plathelminthes in sheep-grazed and ungrazed supralittoral salt marshes of the North Sea: Abundance, biomass, and their significance in food chains

    NASA Astrophysics Data System (ADS)

    Armonies, W.

    The supralittoral salt marshes of the North Sea are marked by high halophyte primary productivity. The environmental factors are strongly fluctuating. Despite these features the metazoan meiofaunal abundance is equal to that found in other littoral habitats. On average 1250 marine metazoans are found per 10 cm 2 in ungrazed and 770 per 10 cm 2 in sheep-grazed supralittoral salt marshes. Nematoda dominate in numerical abundance, Oligochaeta in biomass. Plathelminthes account for 15% of marine metazoans in ungrazed and 5% in grazed salt marshes. Total plathelminth abundance increases with halophyte density, whereas the abundance of diatom-feeding Plathelminthes decreases. In ungrazed marshes on average 104 Plathelminthes are found per 10 cm 2, accounting for a biomass of 0.65 g DW·m -2. In sheep-grazed marshes the average abundance is only 32 individuals per 10 cm 2, accounting for a biomass of 0.1 g DW·m -2. Average individual weight is 3.2 μg DW or 2.5 μg AFDW. In grazed salt marshes, 30% of plathelminthes feed on diatoms, 66% are predators, and 4% feed on bacteria (gut analysis). In ungrazed salt marshes only 3% are diatom-feeders, and 90% are predators feeding on Nematoda, Copepoda, Oligochaeta, and smaller Plathelminthes. Presumably plathelminthes are top predators on the salt marsh meiofauna.

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

    NASA Astrophysics Data System (ADS)

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

    2015-01-01

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

  17. Biodiversity of meiofauna in the intertidal khe nhan mudflat, can gio mangrove forest, vietnam with special emphasis on free living nematodes

    NASA Astrophysics Data System (ADS)

    Xuan, Quang Ngo; Vanreusel, Ann; Thanh, Nguyen Vu; Smol, Nic

    2007-09-01

    The ecological aspect of meiofaunal communities in Can Gio mangrove forest, Ho Chi Minh city, Vietnam has not been investigated before. The composition, distribution, density and biodiversity of meiofaunal communities were studied along an intertidal transect at the Khe Nhan mudflat. Each time, three replicate samples were collected in four stations along a transect following the water line from low tide level up to the mangrove forest edge. In total, 18 meiofaunal taxa were found with the dominant taxa belonging to Nematoda, Copepoda, Sarcomastigophora and Polychaeta. The densities of meiofauna ranged from 1156 inds/10 cm2 to 2082 inds/10 cm2. The increase in densities from the mangrove forest edge towards the low water line was significant. Along the mudflat transect, the biodiversity (expressed by different indices) was relatively high at different taxonomic levels but did not vary significantly along the mudflat except for taxa richness. Eighty nematode genera belonging to 24 families with Comesomatidae having the highest abundance 33.8 % were found. Theristus and Neochromadora decreased in densities from the lower water line towards the mangrove forest edge, while Paracomesoma and Hopperia are typical and more abundant at the middle of the mudflat. Halalaimus increased from high on the mudflat to the low water line.

  18. A qualitative assessment of the influence of bioturbation in Lake Baikal sediments

    NASA Astrophysics Data System (ADS)

    Martin, Patrick; Boes, Xavier; Goddeeris, Boudewijn; Fagel, Nathalie

    2005-04-01

    The impact of bioturbation in Lake Baikal sediments, particularly on rhythmic layering and mixing, was assessed by studying the actual vertical distribution of benthic animals in continuous accumulation zones selected by seismic survey (Vydrino Shoulder, Posolskoe Bank, Continent Ridge). To assess the influence of the bioturbation, animals were extracted from short cores and identified at the relevant taxonomic level. The faunal distribution is examined in parallel with the bioturbation tracks observed in thin section. Oligochaeta, Nematoda, Ostracoda, Copepoda, Gammaridae, Chironomidae and Hydrachnidia were found inhabiting the sediment. Among them, only oligochaete worms were assumed to have a significant impact on sediment mixing because of their "conveyor belt" feeding. The other two most abundantly sampled groups, nematods and copepods, belong to the interstitial fauna that has no significant impact on the vertical displacement of sediment particles and do not ingest the sediment. The presence of a benthic fauna as deep as 15 cm in the sediment indicates that the possibility of sediment disturbance by invertebrate activity cannot be dismissed in Lake Baikal. The effect of biological mixing is more limited in the deepest stations because the number of potential bioturbators is reduced, qualitatively as well as quantitatively. Located in the abyssal zone, Continent and Vydrino (but outside turbidites) deep stations appear to be most promising sediment records for tracking climate signal at high resolution.

  19. Meiofauna associated with a Pacific coral reef in Costa Rica

    NASA Astrophysics Data System (ADS)

    Guzmán, Héctor M.; Obando, Vilma L.; Cortés, Jorge

    1987-10-01

    The meiofauna of two coral reef habitats at Isla del Naño, Costa Rica was studied over a one year period. The dominant groups were: Foraminifera (21.2%), Copepoda (19.7%), Nematoda (19.1%), Gastropoda (16.5%), Polychaeta (7.2%) and Bivalvia (6.6%). The highest diversity was found in coarse, heterogeneous sands with the highest percentage of carbonates. The meiofauna showed a high degree of horizontal aggregation, which is a characteristic pattern for macro- and meiofauna in sediments of variable composition. No vertical variation in distribution was evident, probably due to the deep location of the Redox Potential Discontinuity layer. The total densities of organisms found in this study (99 to 575 ind/10 cm2) are low compared with densities in similar non-reefal sands (7 to 6116), and from fine sediments (80 to 17 000), but are comparable to densities found in other reef areas (39 to 609.5 ind/10 cm2). This is the first report on meiofauna from the eastern Pacific, and the first time that foraminiferans are the dominant group.

  20. Determining Microeukaryotic Plankton Community around Xiamen Island, Southeast China, Using Illumina MiSeq and PCR-DGGE Techniques

    PubMed Central

    Yu, Lingyu; Zhang, Wenjing; Liu, Lemian; Yang, Jun

    2015-01-01

    Microeukaryotic plankton are important components of aquatic environments and play key roles in marine microbial food webs; however, little is known about their genetic diversity in subtropical offshore areas. Here we examined the community composition and genetic diversity of the microeukaryotic plankton in Xiamen offshore water by PCR-DGGE (polymerase chain reaction-denaturing gradient gel electrophoresis), clone-based sequencing and Illumina based sequencing. The Illumina MiSeq sequencing revealed a much (approximately two orders of magnitude) higher species richness of the microeukaryotic community than DGGE, but there were no significant difference in species richness and diversity among the northern, eastern, southern or western stations based on both methods. In this study, Copepoda, Ciliophora, Chlorophyta, Dinophyceae, Cryptophyta and Bacillariophyta (diatoms) were the dominant groups even though diatoms were not detected by DGGE. Our Illumina based results indicated that two northern communities (sites N2 and N3) were significantly different from others in having more protozoa and fewer diatoms. Redundancy analysis (RDA) showed that both temperature and salinity were the significant environmental factors influencing dominant species communities, whereas the full microeukaryotic community appeared to be affected by a complex of environmental factors. Our results suggested that extensive sampling combined with more deep sequencing are needed to obtain the complete diversity of the microeukaryotic community, and different diversity patterns for both abundant and rare taxa may be important in evaluating the marine ecosystem health. PMID:26020532

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

    PubMed

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

    2015-04-01

    Paramacrochiron chironecicola n. sp. (Copepoda: Cyclopoida: Macrochironidae) is described from the highly venomous box jellyfish Chironex sp. collected from Malampaya Sound, Palawan Island, The Philippines. This is the first record of copepods associated with cubozoan medusae, although other cnidarian groups such scyphozoans, hydrozoans, and anthozoans are common hosts for symbiotic copepods. The infection sites were on the subumbrella, pedalium, and rhopalium, but also rarely on the adradial furrow. The new species is distinguished from other congeners by a combination of the following features: (1) the fifth pedigerous somite dorsally covering the anterior part of the female genital double-somite; (2) the fine structures of the antenna (relative lengths of segments) and maxilliped (positions of terminal elements) of the female; (3) the relatively long outer spines on the exopodal segments of legs 1-4; (4) the relatively long and thick female leg 5 bearing a long protopodal seta which reaches to the distal margin of the exopod; (5) the relatively short caudal ramus in the female; and (6) the plump prosome and short urosome in the male. Since members of the genus typically parasitize scyphozoans, especially rhizostomes, the association of this parasitic copepod on cubozoans may reflect the relatively close phylogenetic relationship between cubozoans and scyphozoans. PMID:25826070

  2. Taxonomy, distribution and prevalence of parasites of tigerfish, Hydrocynus vittatus (Castelnau, 1861) in the Sanyati basin, Lake Kariba, Zimbabwe.

    PubMed

    Mabika, Nyasha; Barson, Maxwell; Van Dyk, Cobus; Avenant-Oldewage, Annemariè

    2016-09-01

    Parasites of the tigerfish (Hydrocynus vittatus) were investigated in the period October 2014 to July 2015 in the Sanyati Basin, Lake Kariba. The fish were collected using seine netting and also during the annual Kariba International Tiger Fishing Tournament. A total of 80 fish specimens (24 males and 56 females) were collected and were infected with the following seven parasite taxa: Monogenea (Annulotrema sp.1 from the gills and Annulotrema sp.2 from the skin), Nematoda (Contracaecum larvae), Cestoda (bothriocephalid, larval cyclophyllid), Copepoda (Lamproglena hemprichii), pentastomid, Myxosporea (Myxobolus sp.,) and unicellular ciliate parasites (Trichodina sp., Tetrahymena sp., and unidentified). Annulotrema sp. 1 was observed in all fish and had the highest prevalence, mean intensity and abundance. The fish organs infected were gills, skin, fin, body cavity, stomach, intestines, mesentery, liver, kidney, brain cavity and swim bladder. No parasites were observed in the muscle, eyes and blood. The distribution of the parasites was highest in the gills and lowest in the brain cavity and swimbladder. Bothriocephalids, pentastomes and Trichodina sp. were not observed in male fish. Sex was not related to the intensity of parasites. The results of the study showed that H. vittatus has a richer parasite community than other previous investigated alestids. Pentastomes, Myxobolus sp., Trichodina sp., Tetrahymena sp. and bothriocephalid cestodes are new records for H. vittatus in Zimbabwe. PMID:27447228

  3. Diurnal Changes of Zooplankton Community Reduction Rate at Lake Outlets and Related Environmental Factors

    PubMed Central

    Czerniawski, Robert; Sługocki, Łukasz

    2016-01-01

    The reduced zooplankton abundance at the outlet sections of lakes depends on the occurrence of preying fry. Therefore, light conditions can play a major role in the drift of zooplankton along river outlets. The aim of this study was to determine the influence of diurnal light conditions on the decline of zooplankton densities at lake outlets. Photosynthetically active radiation (PAR) levels were measured to determine their effect on the rate of reduced zooplankton abundance. Cladocerans and copepods showed a significantly greater reduction in abundance than rotifers and nauplii. A significant positive relationship was observed between the PAR levels and the reduced abundance of Asplanchna sp., small cladocerans, large cladocerans and Copepoda at the lake outlets. Among the rotifers, small pelagic rotifers drifted the farthest at all hours of the day. Large crustaceans, especially the large cladocerans and copepodites and adult copepods, had the lowest chance of dispersing over a wide area. Our results indicate that light conditions play an important role in the reduction of zooplankton abundance at lake outlets and have an indirect influence on the downstream food web. PMID:27392017

  4. Feeding habits and ontogenic changes in digestive enzyme patterns in five freshwater teleosts.

    PubMed

    Solovyev, M M; Kashinskaya, E N; Izvekova, G I; Gisbert, E; Glupov, V V

    2014-11-01

    Feeding habits and the activity of digestive enzymes (total alkaline proteases, α-amylase and lipase) from dace Leuciscus leuciscus, roach Rutilus rutilus, Prussian carp Carassius auratus gibelio, perch Perca fluviatilis and pikeperch Sander lucioperca fry were studied in the Malye Chany Lake-Kargat Estuary (western Siberia, Russia). The diet of fry from all studied species was mainly composed of chironomid larvae and zooplanktonic organisms (i.e. cladocera and copepoda), whereas carnivorous species such as P. fluviatilis and S. lucioperca also preyed on fry from other fishes while detritus and microalgae were also important in the diet of ommivorous species. When comparing diet similarity (Sørensen-Dice index, Q(S)) among fry at different stages of development, both omnivorous and carnivorous species showed a high level of similarity (0.67 < Q(S) < 0.89 and 0.73 < Q(S)< 0.89, respectively). Diet similarity values were in agreement with the overall digestive activity profile analysed by cluster analysis. Diet similarity suggested potential trophic competition when zooplanktonic and benthic prey began to decline towards autumn. The analysis of pancreatic digestive enzymes revealed a correlation among their activities and fry feeding habits with α-amylase:total proteases (A:P) values higher than 1 in omnivorous species and lower (A:P ≤ 1) in carnivorous species. PMID:25199648

  5. Effects of 4-nonylphenol on the biota in a littoral pond ecosystem

    SciTech Connect

    Liber, K.; Schmude, K.; O`Halloran, S.; Corry, T.; Gangl, J.; Stay, F.

    1994-12-31

    National water quality criteria for 4-nonylphenol, a surfactant precursor and metabolite, are currently being developed by the US EPA. Preliminary data from laboratory tests indicate that the criterion maximum concentration may be as low as 3--10 {mu}g/L; field data on biological effects are rare. The study presented here was designed to assess the effects of 4-nonylphenol on a natural aquatic community using a set of 18 littoral enclosures (average volume 33 m{sup 3}). The common occurrence of 4-nonylphenol in municipal and industrial discharges dictated the use of a ``chronic`` exposure scenario for this study. Test concentrations ranged from 3 to 300 {mu}g/L, with applications every 48 hours for a 20 day period. This ensured a 21-day ``chronic`` exposure period and allowed sediment concentration of 4-nonylphenol to steadily increase. Survival of juvenile bluegill sunfish was reduced at 300 {mu}g/L, but not at 100, {mu}g/L; no effects on growth were noted over the 68-day assessment period. Abundance of Cladocera and Copepoda were also reduced at 300 {mu}g/L, with recovery observed within 2--4 weeks after the last nonylphenol application. Benthic macroinvertebrates, including Chironomidae, Oligochaeta, and Mollusca, were affected at 100--300 {mu}g/L, with impacts persisting for several months. The slow recovery of benthic macroinvertebrates was partially attributed to their prolonged exposure to sediment associated nonylphenol residues.

  6. Copepod reproductive strategies: life-history theory, phylogenetic pattern and invasion of inland waters

    NASA Astrophysics Data System (ADS)

    Hairston, Nelson G.; Bohonak, Andrew J.

    1998-06-01

    Life-history theory predicts that different reproductive strategies should evolve in environments that differ in resource availability, mortality, seasonality, and in spatial or temporal variation. Within a population, the predicted optimal strategy is driven by tradeoffs that are mediated by the environment in which the organisms live. At the same time, phylogenetic history may circumscribe natural selection by dictating the range of phenotypes upon which selection can act, or by limiting the range of environments encountered. Comparisons of life-history patterns in related organisms provide a powerful tool for understanding both the nature of selection on life-history characters and the diversity of life-history patterns observed in nature. Here, we explore reproductive strategies of the Copepoda, a well defined group with many phylogenetically independent transitions from free-living to parasitic life styles, from marine to inland waters, and from active development to diapause. Most species are iteroparous annuals, and most (with the exception of some parasitic taxa) develop through a relatively restricted range of life-history stages (nauplii and copepodids, or some modification thereof). Within these bounds, we suggest that there may be a causal relationship between the success of numerous copepod taxa in inland waters and the prevalence of either diapause or parasitism within these groups. We hypothesize that inland waters are more variable spatially and temporally than marine habitats, and accordingly, we interpret diapause and parasitism as mechanisms for coping with environmental variance.

  7. Temporal and spatial habitat preferences and biotic interactions between mosquito larvae and antagonistic crustaceans in the field.

    PubMed

    Kroeger, Iris; Liess, Matthias; Duquesne, Sabine

    2014-06-01

    Investigations on natural antagonists of mosquito larvae found that micro-crustaceans (e.g., Cladocera) control mosquito populations under experimental conditions. However, their relevance for mosquito control under field situations remains widely unclear because important information about habitat preferences and time of occurrence of crustaceans and mosquito larvae are still missing. In order to fill this knowledge gap, a field study was undertaken in different wetland areas of Saxony, Germany, in different habitats (i.e., grassland, forest, and reed-covered wetlands). We found negative interactions between larvae of Ae. vexans and predatory Cyclopoida (Crustacean: Copepoda), which both were dominant during the first two weeks of hydroperiod, at ponds located at grassland habitats. Larvae of Cx. pipiens were spatially associated with competing Cladocera, but they colonized ponds more rapidly. Populations of Cladocera established from the third week of hydroperiod and prevented Cx. pipiens colonization thereafter. Ostracoda were highly abundant during the whole hydroperiod, but their presence was restricted to habitats of reed-covered wetland at one geographical area. Mosquito larvae hardly occurred at those ponds. In general, we found that ponds at the reed-covered wetlands provided better conditions for the initial development of crustaceans and hence, mosquito larval colonization was strongly inhibited. Grassland habitat, in contrast, favored early development of mosquito larvae. This study showed that micro-crustaceans are relevant for mosquito management but their impact on mosquito larvae varies between species and depends on environmental conditions. PMID:24820562

  8. Correlations between zooplankton assemblages and environmental factors in the downtown rivers of Shanghai, China

    NASA Astrophysics Data System (ADS)

    Yu, Na; Li, Erchao; Feng, Dexiang; Xiao, Baicai; Wei, Chaoqun; Zhang, Meiling; Chen, Liqiao

    2014-11-01

    Most urban rivers play an important role in urban flood control and drainage in China, but pollution is fast becoming an issue of greater importance in water management. In this study, 63 zooplankton species were recorded in four downtown rivers in Shanghai between November 2007 and October 2008. Of these, 44 species belonged to the Rotifera, 13 to Cladocera, and six to Copepoda. The three most frequently occurring zooplankton ( Brachionus calyciflorus, Microcyclops leuckarti, and Asplanchna priodonta) accounted for 80.00%, 76.84%, and 53.68%, respectively. Rotifera were found to be dominant, comprising 86.26% of total zooplankton, while cladoceran and copepod abundance amounted to 5.08% and 8.67%, respectively. Water temperature, salinity, electrical conductivity, and total nitrogen were of the greatest significance in the occurrence of zooplankton. Two species ( Schmackeria forbesi and Lepadella ovalis) were notably more sensitive to environmental factors such as salinity and electrical conductivity than other species. The population size and community were inversely correlated with the increasing nutrient levels of the four rivers, suggesting that the water quality of the four rivers had been gradually recovering from a severe eutrophic state and that water conditions of the rivers had been gradually improved.

  9. Diet variability of forage fishes in the Northern California Current System

    NASA Astrophysics Data System (ADS)

    Hill, Andrew D.; Daly, Elizabeth A.; Brodeur, Richard D.

    2015-06-01

    As fisheries management shifts to an ecosystem-based approach, understanding energy pathways and trophic relationships in the Northern California Current (NCC) will become increasingly important for predictive modeling and understanding ecosystem response to changing ocean conditions. In the NCC, pelagic forage fishes are a critical link between seasonal and interannual variation in primary production and upper trophic groups. We compared diets among dominant forage fish (sardines, anchovies, herring, and smelts) in the NCC collected in May and June of 2011 and June 2012, and found high diet variability between and within species on seasonal and annual time scales, and also on decadal scales when compared to results of past studies conducted in the early 2000s. Copepoda were a large proportion by weight of several forage fish diets in 2011 and 2012, which differed from a preponderance of Euphausiidae found in previous studies, even though all years exhibited cool ocean conditions. We also examined diet overlap among these species and with co-occurring subyearling Chinook salmon and found that surf smelt diets overlapped more with subyearling Chinook diets than any other forage fish. Herring and sardine diets overlapped the most with each other in our interdecadal comparisons and some prey items were common to all forage fish diets. Forage fish that show plasticity in diet may be more adapted to ocean conditions of low productivity or anomalous prey fields. These findings highlight the variable and not well-understood connections between ocean conditions and energy pathways within the NCC.

  10. Parasite fauna of selected fish species of Lake Miedwie.

    PubMed

    Sobecka, Ewa; Piasecki, Wojciech

    2002-01-01

    A total of 136 fishes, representing 9 species (perch, Perca fluviatilis L.; pike, Esox lucius L.; European eel, Anguilla anguilla (L.); common bream, Abramis brama (L.); roach, Rutilus rutilus (L.); tench Tinca tinca (L.); European whitefish, Coregonus lavaretus (L.); vendace, Coregonus albula (L.); and zander, Sander lucioperca (L.)), from Lake Miedwie were studied within 1997-1999. The necropsies yielded 41 parasite species (taxa). The most diversified were parasite faunas of pike (19 parasite species) and perch (16 species). The parasites found represented 13 higher taxa: Monera, Fungi, Protista, Myxozoa, Monogenea, Cestoda, Digenea, Nematoda, Acanthocephala, Branchiura, Copepoda, Mollusca, and Acarina. The parasites affecting fishes of Lake Miedwie exhibited diversified host-specificity. The most fish species were infected by metacercariae of Diplostomum spp. (8 fish species) and Tylodelphys clavata (7). Three fish species harboured: Ichthyocotylurus platycephalus, Ergasilus sieboldi, and glochidia Unionidae gen. sp. while Dermocystidium sp., Trichodinella epizootica, Henneguya psorospermica, Triaenophorus nodulosus, Posthodiplostomum cuticula, and Camallanus lacustris parasitised two host species. The remaining parasites were found in single fish species. PMID:16888943

  11. Plankton pulses in a temperate coastal embayment during the Winter-Spring transition

    NASA Astrophysics Data System (ADS)

    Elosegui, A.; Pozo, J.; Orive, E.

    1987-06-01

    Hydrographical parameters, phytoplankton productivity and plankton composition were determined over a five-month period in the Bay of Plencia, a coastal area located in the mouth of the river Butron in Biscay, Basque Country. The water column was moderately mixed during most of the study period, which lasted from February to June 1985. Nutrient levels showed high temporal variability and were affected by both river runoff and seasonal biological processes. Nutrients were present most of the time in relatively high concentrations and most of them decreased in late spring. Phytoplankton size structure analysis showed that nanoplankton had the higher chlorophyll content and was responsible for most of the primary production. The phytoplankton showed changes in community composition resulting from the normal progression of the winter-spring conditions. Short-lived peaks of diatom concentration in the spring were followed by periods of low abundance, when maxima of Cladocera and Appendicularia occurred. Total zooplankton showed two peaks of abundance in mid-winter and mid-spring, respectively. Nauplii of Copepoda, juvenile stages of Calanoida and nauplii of Cirripedia were responsible for the two peaks, together with highly seasonal groups (Cladocera, Appendicularia and Cnidaria) in the spring maxima. Primary production seems to be driven by physical processes (temperature, short photoperiod and storms) in winter, whereas depletion of nutrients and grazing by zooplankton are responsible for phytoplankton minima between peaks of abundance in the growing season. Two temporal phases were apparent when the data were analysed by a principal component analysis.

  12. Seasonal variation in the copepod community structure from a tropical Amazon estuary, Northern Brazil.

    PubMed

    Magalhães, André; Leite, Natália da R; Silva, João G S; Pereira, Luci C C; Costa, Rauquírio M da

    2009-06-01

    The main purpose of this study was to investigate the seasonal variation of copepod community structure during the months of July, September and November 2003 (dry season) and January, March and May 2004 (rainy season) in the Curuçá estuary, northern Brazil. Samples were collected during neap tides via gentle 200microm mesh net tows from a small powerboat. Measurements of surface water conductivity were accomplished in situ using an electronic conductivimeter and salinity was later obtained through the transformation of the conductivity values. Salinity varied seasonally from 7.2 +/- 0.1 to 39.2 +/- 1.8 (mean +/- standard deviation) and was influenced mainly by differences in the amount of rainfall between the studied sampling seasons. In total, 30 Copepoda taxa were identified and Acartia tonsa comprised the most representative species throughout the entire studied period followed by Acartia lilljeborgii, Subeucalanus pileatus and Paracalanus quasimodo. In the present study, the density values, ecological indexes and copepod species dominance presented a clear seasonal pattern, showing that the studied area may be considered seasonally heterogeneous in relation to the investigated parameters. PMID:19488623

  13. Changes in zooplankton diversity and distribution pattern under varying precipitation regimes in a southern temperate estuary

    NASA Astrophysics Data System (ADS)

    Primo, Ana Lígia; Azeiteiro, Ulisses Miranda; Marques, Sónia Cotrim; Martinho, Filipe; Pardal, Miguel Ângelo

    2009-04-01

    The influence of climate variability on the diversity and distribution patterns of zooplankton communities was investigated in the Mondego estuary (Portugal) during four consecutive years characterized by highly variable precipitation and, consequently, river flow regime. Monthly samples were collected along the estuarine gradient at five sampling stations. Seasonal, inter-annual and spatial distributions were evaluated by multivariate analyses and three diversity indices were applied (Species number, Shannon Diversity and Average Taxonomic Distinctness). A two-year drought period presented significant differences in salinity values, especially in 2005 (extreme drought event). During the study period, copepoda was the main dominant group and Acartia tonsa the most abundant species, with the exception of autumn 2006, where high abundances of the cladoceran Penilia avirostris were noticed. Multivariate analysis indicated that zooplankton communities changed from a pre- to a post-drought period indicating the influence of hydrological parameters in communities' structure. The dry period was associated with an increase in zooplankton density, a reduction in seasonality and higher abundance and prevalence of marine species throughout the year. Seasonally, winter/spring communities were distinct from those in summer/autumn. Spatially, salinity-associated differences between upstream and downstream communities were reduced during the drought years, but during the post-drought year, these differences were detected again.

  14. Effects of habitat structure on the epifaunal community in Mussismilia corals: does coral morphology influence the richness and abundance of associated crustacean fauna?

    NASA Astrophysics Data System (ADS)

    Nogueira, Marcos M.; Neves, Elizabeth; Johnsson, Rodrigo

    2015-06-01

    Coral habitat structures increase abundance and richness of organisms by providing niches, easy access to resources and refuge from predators. Corals harbor a great variety of animals; the variation in coral species morphology contributes to the heterogeneity and complexity of habitat types. In this report, we studied the richness and abundance of crustaceans (Decapoda, Copepoda, Peracarida and Ostracoda) associated with three species of Mussismilia exhibiting different growth morphologies, in two different coral reefs of the Bahia state (Caramuanas and Boipeba-Moreré, Brazil). Mussismilia hispida is a massive coral; M. braziliensis also has a massive growth pattern, but forms a crevice in the basal area of the corallum; M. harttii has a meandroid pattern. PERMANOVA analysis suggests significant differences in associated fauna richness among Mussismilia species, with higher values for M. harttii, followed by M. braziliensis and later by M. hispida. The same trend was observed for density, except that the comparison of M. braziliensis and M. hispida did not show differences. Redundancy and canonical correspondence analysis indicated that almost all of the crustacean species were more associated with the M. harttii colonies that formed a group clearly separated from colonies of M. braziliensis and M. hispida. We also found that the internal volume of interpolyp space, only present in M. harttii, was the most important factor influencing richness and abundance of all analyzed orders of crustaceans.

  15. Epibiotic macrofauna on common minke whales, Balaenoptera acutorostrata Lacépède, 1804, in Icelandic waters

    PubMed Central

    2013-01-01

    Background Whilst there is a body of scientific literature relating to the epibiotic macrofauna on large whales, there is little information on the cetaceans in Icelandic waters. Common minke whales, Balaenoptera acutorostrata Lacépède, 1804, are a common sighting between the months of April to November, however, the migration and distribution of the population in winter requires establishing. The present study provides baseline information on the species composition, geographic distribution and abundance of the epibiotic macrofauna on minke whales landed in Icelandic waters and comments on their acquisition. Methods The epibiotic macrofauna and skin lesions on 185 and 188 common minke whales respectively, landed in Icelandic waters between April to September 2003-2007 were determined. For each whale, the fluke and one lateral side was examined. Results A total of seven epibiotic species were found: the caligid copepod Caligus elongatus (prevalence (P) = 11.9%, mean intensity (M.I) = 95.5); the pennellid copepod Pennella balaenopterae (P = 10.3%, M.I = 1.6); the cyamid amphipod Cyamus balaenopterae (P = 6.5%, M.I = 37.0); the lepadid cirripedes Conchoderma virgatum (P = 0.5%, M.I = 4.0) and Conchoderma auritum (P = 0.5%, M.I = 1.0), the balanid cirriped Xenobalanus globicipitis (P = 1.6%, M.I = 5.3) and the sea lamprey Petromyzon marinus (P = 2.7%, M.I = 1.0). In addition, the hyperparasitic monogenean Udonella caligorum was found on C. elongatus (P = 6.6%) on 8 of the 22 whales infected with the copepod. No significant relationship was observed between parasite intensity and host body length for either C. balaenopterae or C. elongatus, while the proportion of infected hosts was higher in August-September than earlier in the summer for C. balaenopterae (χ2 = 13.69; p<0.01: d.f.=1) and C. elongatus (χ2 = 28.88; p<0.01: d.f.=1). Conclusions The higher prevalence of C. balaenopterae on male whales (χ2 = 5.08; p<0.05: d.f.=1), suggests possible different migration

  16. Parasite fauna of bream Abramis brama and roach Rutilus rutilus from a man-made waterway and a freshwater habitat in northern Germany.

    PubMed

    Rückert, Sonja; Klimpel, Sven; Palm, Harry Wilhelm

    2007-03-13

    Fifty specimens each of bream Abramis brama and roach Rutilus rutilus were examined for metazoan parasite fauna and trichodinid ciliates; 25 specimens of each species were collected from the Kiel Canal, a man-made waterway, and a nearby freshwater lake, the Dieksee. This is the first detailed parasitological examination of A. brama and R. rutilus at these locations: 30 parasite species were found, comprising 4 protozoans, 4 myxozoans, 5 digeneans, 3 monogeneans, 2 cestodes, 6 nematodes, 2 acanthocephalans, 3 crustaceans and 1 hirudinean. The crustacean Caligus lacustris occurred in both habitats while 2 other crustacean species, 2 acanthocephalans and 1 hirudinean were recorded exclusively for the lake habitat. Larval as well as adult stages of the different parasite species were found, indicating that both fish species act as intermediate and final hosts in both habitats. The Kiel Canal (total of 17 parasite species) showed a lower parasite species richness for A. brama and R. rutilus (14 and 10 parasite species, respectively) than the lake (25 parasite species). A. brama had a higher parasite richness (22 species) than R. rutilus (16 species) in the lake habitat. Most parasites collected were of freshwater origin. Consequently, the observed infection pattern of both fish species in the waterway is mainly influenced by the limited salinity tolerance of freshwater parasites, which are negatively affected even by a salinity of 2.3 to 4.5. In the central Kiel Canal, neither fish species was infected with marine parasites of low host specifity. These parasites are either limited by the low salinity at this sampling site (<4.5 to 6.0) or they cannot enter the canal due to the environmental conditions prevailing in this artificial brackish water habitat. Thus, the canal may comprise a natural barrier preventing the distribution of North Sea parasites into the Baltic Sea. However, the brackish water Baltic Sea nematodes Paracuaria adunca and Cosmocephalus obvelatus were

  17. Toxicity Overrides Morphology on Cylindrospermopsis raciborskii Grazing Resistance to the Calanoid Copepod Eudiaptomus gracilis.

    PubMed

    Rangel, Luciana M; Ger, Kemal A; Silva, Lúcia H S; Soares, Maria Carolina S; Faassen, Elisabeth J; Lürling, Miquel

    2016-05-01

    Toxicity and morphology may function as defense mechanisms of bloom-forming cyanobacteria against zooplankton grazing. Yet, the relative importance of each of these factors and their plasticity remains poorly known. We tested the effects of chemical and morphological traits of the bloom-forming cyanobacterium Cylindrospermopsis raciborskii on the feeding response of the selective feeder Eudiaptomus gracilis (Calanoida, Copepoda), using a saxitoxin-producing strain (STX+) and a non-saxitoxin (STX-)-producing strain as food. From these two chemotypes, we established cultures of three different morphotypes that differed in filament length (short, medium, and long) by incubating the strains at 17, 25, and 32 °C. We hypothesized that the inhibitory effects of saxitoxins determine the avoidance of C. raciborskii, and that morphology would only become relevant in the absence of saxitoxins. Temperature affected two traits: higher temperature resulted in significantly shorter filaments in both strains and led to much higher toxin contents in the STX+ strain (1.7 μg eq STX L(-1) at 17 °C, 7.9 μg eq STX L(-1) at 25 °C, and 25.1 μg eq STX L(-1) at 32 °C). Copepods strongly reduced the ingestion of the STX+ strain in comparison with STX- cultures, regardless of filament length. Conversely, consumption of shorter filaments was significantly higher in the STX- strain. The great plasticity of morphological and chemical traits of C. raciborskii and their resultant contrasting effects on the feeding behavior of zooplankton might explain the success of this cyanobacterium in a variety of aquatic environments. PMID:26888523

  18. The mitochondrial genomes of Amphiascoides atopus and Schizopera knabeni (Harpacticoida: Miraciidae) reveal similarities between the copepod orders Harpacticoida and Poecilostomatoida.

    PubMed

    Easton, Erin E; Darrow, Emily M; Spears, Trisha; Thistle, David

    2014-03-15

    Members of subclass Copepoda are abundant, diverse, and-as a result of their variety of ecological roles in marine and freshwater environments-important, but their phylogenetic interrelationships are unclear. Recent studies of arthropods have used gene arrangements in the mitochondrial (mt) genome to infer phylogenies, but for copepods, only seven complete mt genomes have been published. These data revealed several within-order and few among-order similarities. To increase the data available for comparisons, we sequenced the complete mt genome (13,831base pairs) of Amphiascoides atopus and 10,649base pairs of the mt genome of Schizopera knabeni (both in the family Miraciidae of the order Harpacticoida). Comparison of our data to those for Tigriopus japonicus (family Harpacticidae, order Harpacticoida) revealed similarities in gene arrangement among these three species that were consistent with those found within and among families of other copepod orders. Comparison of the mt genomes of our species with those known from other copepod orders revealed the arrangement of mt genes of our Harpacticoida species to be more similar to that of Sinergasilus polycolpus (order Poecilostomatoida) than to that of T. japonicus. The similarities between S. polycolpus and our species are the first to be noted across the boundaries of copepod orders and support the possibility that mt-gene arrangement might be used to infer copepod phylogenies. We also found that our two species had extremely truncated transfer RNAs and that gene overlaps occurred much more frequently than has been reported for other copepod mt genomes. PMID:24389499

  19. Egg number-egg size: an important trade-off in parasite life history strategies.

    PubMed

    Cavaleiro, Francisca I; Santos, Maria J

    2014-03-01

    Parasites produce from just a few to many eggs of variable size, but our understanding of the factors driving variation in these two life history traits at the intraspecific level is still very fragmentary. This study evaluates the importance of performing multilevel analyses on egg number and egg size, while characterising parasite life history strategies. A total of 120 ovigerous females of Octopicola superba (Copepoda: Octopicolidae) (one sample (n=30) per season) were characterised with respect to different body dimensions (total length; genital somite length) and measures of reproductive effort (fecundity; mean egg diameter; total reproductive effort; mean egg sac length). While endoparasites are suggested to follow both an r- and K-strategy simultaneously, the evidence found in this and other studies suggests that environmental conditions force ectoparasites into one of the two alternatives. The positive and negative skewness of the distributions of fecundity and mean egg diameter, respectively, suggest that O. superba is mainly a K-strategist (i.e. produces a relatively small number of large, well provisioned eggs). Significant sample differences were recorded concomitantly for all body dimensions and measures of reproductive effort, while a general linear model detected a significant influence of season*parasite total length in both egg number and size. This evidence suggests adaptive phenotypic plasticity in body dimensions and size-mediated changes in egg production. Seasonal changes in partitioning of resources between egg number and size resulted in significant differences in egg sac length but not in total reproductive effort. Evidence for a trade-off between egg number and size was found while controlling for a potential confounding effect of parasite total length. However, this trade-off became apparent only at high fecundity levels, suggesting a state of physiological exhaustion. PMID:24462500

  20. Aquatic safety of Lagenidium giganteum: effects on freshwater fish and invertebrates.

    PubMed

    Nestrud, L B; Anderson, R L

    1994-11-01

    Eleven freshwater species were exposed to a zoosporeproducing fungus, Lagenidium giganteum, with the goal of determining species sensitivity with standard and new test procedures. The tests included standard, 4-day acute exposures of cladocerans (Ceriodaphnia dubia, Daphnia pulex, and D. magna) and the fathead minnow (Pimephales promelas). Standard 7-day chronic exposures of C. dubia and a 7-day embryo-larval exposure of P. promelas were also conducted. New, 4-day acute, methods were developed for mosquitos (Aedes aegypti), chironomids (Chironomus sp.), oligochaetes (Lumbriculus sp.), cyclopoid copepods, snails (Physa sp.), hydrozoans (Hydra sp.), and ostracods. To assess L. giganteum zoospore (z) infectivity, each test included daily bioassays with the mosquito (A. aegypti), a target organism. Four-day A. aegypti LC50s ranged from 81 to 516 z/ml. Ceriodaphnia dubia acute test LC50s were as low as 6700 z/ml and the 96-hr LC50 from the chronic test was near 6250 z/ml with reproductive impairment at 12,500 z/ml. Daphnia sp. were also susceptible, with LC50s near 7700 z/ml for D. pulex and 9400 z/ml for D. magna. Chironomus tentans was infected at concentrations of > or = 5000 z/ml, but mortality was low and an LC50 could not be calculated even after exposures to 50,000 z/ml. The 7-day, early life stage test with P. promelas produced reduced larva growth in most treatments. Several species (Hydra sp., L. variegatus, ostracoda, copepoda, Physa sp., and P. promelas) were not affected in acute tests at exposures of 50,000 z/ml. The data show, contrary to many reports, that L. giganteum may affect some nontarget aquatic species. The key to successful laboratory tests is monitoring and maintaining the zoospores infection capacity. PMID:7806894

  1. Sensitivity of hypogean and epigean freshwater copepods to agricultural pollutants.

    PubMed

    Di Lorenzo, T; Di Marzio, W D; Sáenz, M E; Baratti, M; Dedonno, A A; Iannucci, A; Cannicci, S; Messana, G; Galassi, D M P

    2014-03-01

    Widespread pollution from agriculture is one of the major causes of the poor freshwater quality currently observed across Europe. Several studies have addressed the direct impact of agricultural pollutants on freshwater biota by means of laboratory bioassays; however, as far as copepod crustaceans are concerned, the ecotoxicological research is scarce for freshwater species and almost nonexistent for the hypogean ones. In this study, we conducted a comparative analysis of the available literature data on the sensitivity of freshwater copepods to agricultural pollutants. We also assessed the acute and chronic sensitivity of a hypogean and an epigean species, both belonging to the Crustacea Copepoda Cyclopoida Cyclopidae, to two N-fertilizers (urea and ammonium nitrate) and two herbicides (ARIANE(TM) II from Dow AgroSciences LLC, and Imazamox), widely used for cereal agriculture in Europe. According to the literature review, freshwater copepods are sensitive to a range of pesticides and N-fertilizers. Ecotoxicological studies on hypogean species of copepods account only one study. There are no standardized protocols available for acute and chronic toxicity tests for freshwater copepods, making comparisons about sensitivity difficult. From our experiments, ionized ammonia proved to be more toxic than the herbicide Imazamox, in both short and chronic bioassays. Urea was the less toxic chemical for both species. The hypogean species was more sensitive than the epigean one to all chemicals. For both species and for all tested chemicals, acute lethality and chronic lethality were induced at concentrations higher than the law limits of good water body quality in Europe, except for ionized ammonia, which provoked the chronic lethality of the hypogean species at a lower concentration. The hazardous concentration (HC) of un-ionized ammonia for 5 % of freshwater copepods, obtained by a species sensitivity distribution, was 92 μg l(-1), significantly lower than the HC computed

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

    PubMed Central

    Lajus, Dmitry; Sukhikh, Natalia; Alekseev, Victor

    2015-01-01

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

  3. Ecological impacts of fluridone and copper sulphate in catfish aquaculture ponds.

    PubMed

    Jacob, Annie P; Culver, David A; Lanno, Roman P; Voigt, Astrid

    2016-05-01

    Fluridone and copper sulphate are often used for controlling macrophytes and algae in aquaculture ponds. The present study examined the ecological effects of these chemicals on macrophyte, phytoplankton, and zooplankton biomass; plankton community structure; water quality parameters; and fish survival and yield in catfish culture ponds using a randomized complete block design. The estimated half-life of fluridone in the individual ponds ranged from 1.6 d to 10.8 d. Free copper ion activity in ponds treated with copper sulphate was dynamic, ranging from pCu of 7.7 to 8.9 after each application and decreasing to approximately 12 (1 × 10(-12)  M) within 1 wk after each application, approaching observed values in control ponds (pCu = 12.3-13.4). No difference in macrophyte biomass was observed among treatments. Fluridone and copper treatments elicited different responses within the phytoplankton community. Copper treatments reduced Cyanophyta biomass but increased biomass of more tolerant taxa among the Chlorophyta and Chrysophyta. Fluridone treatments reduced total phytoplankton biomass including Cyanophyta and increased the sensitivity of Chlorophyta and Chrysophyta to copper. Copper also affected zooplankton community composition as a result of direct toxic effects on sensitive zooplankton taxa (e.g., Cladocera), whereas Copepoda biomass in copper-treated ponds exceeded that in controls. Catfish survival and yield were not significantly different among treatments. The results of the present study suggest that fluridone and copper interact at realistic application rates, increasing the ability to control algae compared with treatments where they are applied alone. PMID:26395963

  4. The Bass Parasites of Oneida Lake, 80 Years Later.

    PubMed

    Bauer, Eric F; Whipps, Christopher M

    2015-10-01

    A survey of largemouth (Micropterus salmoides) and smallmouth bass (Micropterus dolomieu) parasite communities in Oneida Lake, New York, was conducted in the summer of 2012 and compared to an earlier survey conducted by Van Cleave and Mueller during the summers of 1929 to 1931. The component helminth communities between surveys were 31% similar in composition for largemouth and 28% similar for smallmouth bass. Between species, the component helminth communities were considerably more similar in the present survey (71%) than in the survey conducted by Van Cleave and Mueller (47%). Seven species reported by Van Cleave and Mueller were present in this survey and 21 species are new records for the bass of Oneida Lake. Van Cleave and Mueller did not report prevalence values for several taxa (Monogenea, Copepoda, Myxozoa, and a Trichodina sp.) that were important for separation of parasite infracommunities in species space for both bass species. These parasites represented 28% of all species found in the current survey and may be ecologically important. Several species of parasites exhibited differences in prevalence between surveys. Two species (Rhipidocotyle papillosa and Crepidostomum cornutum) were absent from this survey but were reported as common in the 1929-1931 survey and almost certainly represent extirpations that coincide with the loss of their native bivalve hosts from Oneida Lake. Other differences in the parasite communities may also be explained by the ecological disturbances in Oneida Lake over the past 81 yr. The changes in bass parasite communities between surveys emphasize the importance of recognizing the historical nature of parasite communities, especially in ecosystems with a history of large-scale changes. Most importantly our findings suggest that, similar to trends observed in free-living freshwater biotic communities, anthropogenic ecosystem disturbances may homogenize fish parasite communities. PMID:26001048

  5. Evolution of Respiratory Proteins across the Pancrustacea.

    PubMed

    Burmester, Thorsten

    2015-11-01

    Respiratory proteins enhance the capacity of the blood for oxygen transport and support intracellular storage and delivery of oxygen. Hemocyanin and hemoglobin are the respiratory proteins that occur in the Pancrustacea. The copper-containing hemocyanins evolved from phenoloxidases in the stem lineage of arthropods. For a long time, hemocyanins had only been known from the malacostracan crustaceans but recent studies identified hemocyanin also in Remipedia, Ostracoda, and Branchiura. Hemoglobins are common in the Branchiopoda but have also been sporadically found in other crustacean classes (Malacostraca, Copepoda, Thecostraca). Respiratory proteins had long been considered unnecessary in the hexapods because of the tracheal system. Only chironomids, some backswimmers, and the horse botfly, which all live under hypoxic conditions, were known exceptions and possess hemoglobins. However, recent data suggest that hemocyanins occur in most ametabolous and hemimetabolous insects. Phylogenetic analysis showed the hemocyanins of insects and Remipedia to be similar, suggesting a close relationship of these taxa. Hemocyanin has been lost in dragonflies, mayflies, and Eumetabola (Hemiptera + Holometabola). In cockroaches and grasshoppers, hemocyanin expression is restricted to the developing embryo while in adults oxygen is supplied solely by the tracheal system. This pattern suggests that hemocyanin was the oxygen-transport protein in the hemolymph of the last common ancestor of the pancrustaceans. The loss was probably associated with miniaturization, a period of restricted availability of oxygen, a change in life-style, or morphological changes. Once lost, hemocyanin was not regained. Some pancrustaceans also possess cellular globin genes with uncertain functions, which are expressed at low levels. When a respiratory protein was again required, hemoglobins evolved several times independently from cellular globins. PMID:26130703

  6. Indicator Properties of Baltic Zooplankton for Classification of Environmental Status within Marine Strategy Framework Directive

    PubMed Central

    Lehtiniemi, Maiju; Postel, Lutz; Rubene, Gunta; Amid, Callis; Lesutiene, Jurate; Uusitalo, Laura; Strake, Solvita; Demereckiene, Natalja

    2016-01-01

    The European Marine Strategy Framework Directive requires the EU Member States to estimate the level of anthropogenic impacts on their marine systems using 11 Descriptors. Assessing food web response to altered habitats is addressed by Descriptor 4 and its indicators, which are being developed for regional seas. However, the development of simple foodweb indicators able to assess the health of ecologically diverse, spatially variable and complex interactions is challenging. Zooplankton is a key element in marine foodwebs and thus comprise an important part of overall ecosystem health. Here, we review work on zooplankton indicator development using long-term data sets across the Baltic Sea and report the main findings. A suite of zooplankton community metrics were evaluated as putative ecological indicators that track community state in relation to Good Environmental Status (GES) criteria with regard to eutrophication and fish feeding conditions in the Baltic Sea. On the basis of an operational definition of GES, we propose mean body mass of zooplankton in the community in combination with zooplankton stock measured as either abundance or biomass to be applicable as an integrated indicator that could be used within the Descriptor 4 in the Baltic Sea. These metrics performed best in predicting zooplankton being in-GES when considering all datasets evaluated. However, some other metrics, such as copepod biomass, the contribution of copepods to the total zooplankton biomass or biomass-based Cladocera: Copepoda ratio, were equally reliable or even superior in certain basin-specific assessments. Our evaluation suggests that in several basins of the Baltic Sea, zooplankton communities currently appear to be out-of-GES, being comprised by smaller zooplankters and having lower total abundance or biomass compared to the communities during the reference conditions; however, the changes in the taxonomic structure underlying these trends vary widely across the sea basins due to

  7. Strong Spatial Influence on Colonization Rates in a Pioneer Zooplankton Metacommunity

    PubMed Central

    Frisch, Dagmar; Cottenie, Karl; Badosa, Anna; Green, Andy J.

    2012-01-01

    The magnitude of community-wide dispersal is central to metacommunity models, yet dispersal is notoriously difficult to quantify in passive and cryptic dispersers such as many freshwater invertebrates. By overcoming the problem of quantifying dispersal rates, colonization rates into new habitats can provide a useful estimate of the magnitude of effective dispersal. Here we study the influence of spatial and local processes on colonization rates into new ponds that indicate differential dispersal limitation of major zooplankton taxa, with important implications for metacommunity dynamics. We identify regional and local factors that affect zooplankton colonization rates and spatial patterns in a large-scale experimental system. Our study differs from others in the unique setup of the experimental pond area by which we were able to test spatial and environmental variables at a large spatial scale. We quantified colonization rates separately for the Copepoda, Cladocera and Rotifera from samples collected over a period of 21 months in 48 newly constructed temporary ponds of 0.18–2.95 ha distributed in a restored wetland area of 2,700 ha in Doñana National Park, Southern Spain. Species richness upon initial sampling of new ponds was about one third of that in reference ponds, although the rate of detection of new species from thereon were not significantly different, probably owing to high turnover in the dynamic, temporary reference ponds. Environmental heterogeneity had no detectable effect on colonization rates in new ponds. In contrast, connectivity, space (based on latitude and longitude) and surface area were key determinants of colonization rates for copepods and cladocerans. This suggests dispersal limitation in cladocerans and copepods, but not in rotifers, possibly due to differences in propagule size and abundance. PMID:22792241

  8. Meiofauna abundance on the Gulf of Mexico continental shelf affected by hypoxia

    NASA Astrophysics Data System (ADS)

    Murrell, Michael C.; Fleeger, John W.

    1989-12-01

    Meiofauna were sampled in shallow (8-13 m) continental shelf waters off the coast of Louisiana at three stations on 13 dates from June 1985 to August 1986. Total meiofauna abundances ranged from 525 to 3406 individuals per 10 cm 2 with a mean of 1810 individuals per 10 cm 2. Peak abundances occurred in late spring and early summer while seasonal lows occurred during late summer and winter. The three predominant taxa were Nematoda (91.8%), Copepoda (3.2%) and Kinorhyncha (2.5%). The meiobenthic copepod assemblage displayed low diversity and was dominated by three epibenthic species which together comprised 87% of the copepod fauna. Hypoxic conditions (dissolved oxygen <2mg l -1) developed seasonally on this shelf as a result of water column density stratification and eutrophication during late spring and summer. Abundances of all taxa declined during the summers of both years apparently in response to hypoxic conditions. Copepods were most dramatically affected, dropping from springtime peak abundances (several hundred per 10 cm 2) to virtually zero in a one-month period of time. Copepod density declines were spatially correlated with the onset of hypoxia, as inshore stations developed hypoxia later and underwent declines later. Densities remained low after the return of normal oxygen conditions, rising in the spring of the following year. The effect on nematodes and kinorhynchs was not as dramatic. A single collection of meiofauna from July 1983 in nearby normoxic Terrebonne Bay at similar water depths reveals a high density and diversity of copepods, further suggesting the sensitivity of copepods to hypoxia.

  9. Indicator Properties of Baltic Zooplankton for Classification of Environmental Status within Marine Strategy Framework Directive.

    PubMed

    Gorokhova, Elena; Lehtiniemi, Maiju; Postel, Lutz; Rubene, Gunta; Amid, Callis; Lesutiene, Jurate; Uusitalo, Laura; Strake, Solvita; Demereckiene, Natalja

    2016-01-01

    The European Marine Strategy Framework Directive requires the EU Member States to estimate the level of anthropogenic impacts on their marine systems using 11 Descriptors. Assessing food web response to altered habitats is addressed by Descriptor 4 and its indicators, which are being developed for regional seas. However, the development of simple foodweb indicators able to assess the health of ecologically diverse, spatially variable and complex interactions is challenging. Zooplankton is a key element in marine foodwebs and thus comprise an important part of overall ecosystem health. Here, we review work on zooplankton indicator development using long-term data sets across the Baltic Sea and report the main findings. A suite of zooplankton community metrics were evaluated as putative ecological indicators that track community state in relation to Good Environmental Status (GES) criteria with regard to eutrophication and fish feeding conditions in the Baltic Sea. On the basis of an operational definition of GES, we propose mean body mass of zooplankton in the community in combination with zooplankton stock measured as either abundance or biomass to be applicable as an integrated indicator that could be used within the Descriptor 4 in the Baltic Sea. These metrics performed best in predicting zooplankton being in-GES when considering all datasets evaluated. However, some other metrics, such as copepod biomass, the contribution of copepods to the total zooplankton biomass or biomass-based Cladocera: Copepoda ratio, were equally reliable or even superior in certain basin-specific assessments. Our evaluation suggests that in several basins of the Baltic Sea, zooplankton communities currently appear to be out-of-GES, being comprised by smaller zooplankters and having lower total abundance or biomass compared to the communities during the reference conditions; however, the changes in the taxonomic structure underlying these trends vary widely across the sea basins due to

  10. Macroparasites and their communities of the European eel Anguilla anguilla (Linnaeus) in the Czech Republic.

    PubMed

    Moravec, Frantisek; Scholz, Tomas

    2015-01-01

    This paper summarises the results of parasitological examinations of the European eel Anguilla anguilla (Linnaeus) in the Czech Republic, carried out at the Institute of Parasitology, Czech Academy of Sciences (previously the Czechoslovak Academy of Sciences) within the period of 50 years (1958-2008). Even though this survey is limited to the Czech Republic, it provides extensive data probably incomparable with any other study anywhere regarding the number of eels examined and parasites found. A total of 723 eels was examined from 42 localities that belong to all of the three main river drainage systems in the country, i.e. the Elbe, Danube and Oder river basins. Of the 31 species of adult and larval macroparasites including Monogenea (4 species), Trematoda (3), Cestoda (3), Nematoda (11), Acanthocephala (5), Hirudinea (1), Bivalvia (1), Copepoda (1), Branchiura (1) and Acariformes (1), most of them (30) were recorded from the Elbe River basin. These parasites can be divided into three main groups regarding their host specificity: parasites specific for eels (26%), non-specific adult parasites occurring also in other fishes (61%) and non-specific larvae (13%). The highest number (19) of parasite species was recorded in the Mácha Lake fishpond system in northern Bohemia. The parasite communities in eels from the individual localities exhibited large differences in their species composition and diversity depending on local ecological conditions. The parasite fauna of A. anguilla in the Czech Republic is compared with that in other European countries. The nematode Cucullanus egyptae Abdel-Ghaffar, Bashtar, Abdel-Gaber, Morsy, Mehlhorn, Al Quraishy et Mohammed, 2014 is designated as a species inquirenda. PMID:26130652

  11. Next Generation Sequencing Reveals the Hidden Diversity of Zooplankton Assemblages

    PubMed Central

    Harmer, Rachel A.; Somerfield, Paul J.; Atkinson, Angus

    2013-01-01

    Background Zooplankton play an important role in our oceans, in biogeochemical cycling and providing a food source for commercially important fish larvae. However, difficulties in correctly identifying zooplankton hinder our understanding of their roles in marine ecosystem functioning, and can prevent detection of long term changes in their community structure. The advent of massively parallel next generation sequencing technology allows DNA sequence data to be recovered directly from whole community samples. Here we assess the ability of such sequencing to quantify richness and diversity of a mixed zooplankton assemblage from a productive time series site in the Western English Channel. Methodology/Principle Findings Plankton net hauls (200 µm) were taken at the Western Channel Observatory station L4 in September 2010 and January 2011. These samples were analysed by microscopy and metagenetic analysis of the 18S nuclear small subunit ribosomal RNA gene using the 454 pyrosequencing platform. Following quality control a total of 419,041 sequences were obtained for all samples. The sequences clustered into 205 operational taxonomic units using a 97% similarity cut-off. Allocation of taxonomy by comparison with the National Centre for Biotechnology Information database identified 135 OTUs to species level, 11 to genus level and 1 to order, <2.5% of sequences were classified as unknowns. By comparison a skilled microscopic analyst was able to routinely enumerate only 58 taxonomic groups. Conclusions Metagenetics reveals a previously hidden taxonomic richness, especially for Copepoda and hard-to-identify meroplankton such as Bivalvia, Gastropoda and Polychaeta. It also reveals rare species and parasites. We conclude that Next Generation Sequencing of 18S amplicons is a powerful tool for elucidating the true diversity and species richness of zooplankton communities. While this approach allows for broad diversity assessments of plankton it may become increasingly

  12. Temporal and spatial distribution of the meiobenthic community in Daya Bay, South China Sea

    NASA Astrophysics Data System (ADS)

    Tang, L.; Li, H. X.; Yan, Y.

    2012-04-01

    Spatial and temporal biodiversity patterns of the meiobenthos were studied for the first time in Daya Bay, which is a tropical semi-enclosed basin located in the South China Sea. The abundance, biomass, and composition of the meiobenthos and the basic environmental factors in the bay were investigated. The following 19 taxonomic groups were represented in the meiofauna: Nematoda, Copepoda, Polychaeta, Oligochaeta, Kinorhyncha, Gastrotricha, Ostracoda, Bivalvia, Turbellaria, Nemertinea, Sipuncula, Hydroida, Amphipoda, Cumacea, Halacaroidea, Priapulida, Echinodermata, Tanaidacea, and Rotifera. Total abundance and biomass of the meiobenthos showed great spatial and temporal variation, with mean values of 993.57 ± 455.36 ind cm-2 and 690.51 ± 210.64 μg 10 cm-2, respectively. Nematodes constituted 95.60 % of the total abundance and thus had the greatest effect on meiofauna quantity and distribution, followed by copepods (1.55 %) and polychaetes (1.39 %). Meiobenthos abundance was significantly negatively correlated with water depth at stations (r=-0.747, P<0.05) and significantly negatively correlated with silt-clay content (r=-0.516, P<0.01) and medium diameter (r=-0.499, P<0.01) of the sediment. Similar results were found for correlations of biomass and abundance of nematodes with environmental parameters. Polychaete abundance was positively correlated with the bottom water temperature (r=0.456, P<0.01). Meiobenthos abundance differed significantly among seasons (P<0.05), although no significant difference among stations and the interaction of station × season was detected by two-way ANOVA. In terms of vertical distribution, most of the meiobenthos was found in the surface layer of sediment. This pattern was apparent for nematodes and copepods, but a vertical distribution pattern for polychaetes was not as obvious. Based on the biotic indices and analyses of their correlations and variance, the diversity of this community was likely to be influenced by

  13. Fish parasites in the bathyal zone: The halosaur Halosauropsis macrochir (Günther, 1878) from the Mid-Atlantic Ridge

    NASA Astrophysics Data System (ADS)

    Klimpel, S.; Palm, H. W.; Busch, M. W.; Kellermanns, E.

    2008-01-01

    A total of 42 Halosauropsis macrochir from a single position on the Mid-Atlantic Ridge (MAR) were collected for studies on parasites and feeding ecology. A total of 9 different parasite species were found, with most of them belonging to the Digenea (4 species) and Nematoda (3). The host specific Degeneria halosauri, (Digenea) and Cystidicolidae indet. (Nematoda) were the predominant species, reaching a prevalence of 100.0% and 57.1% with intensities of infection of 1-12 and 1-10, respectively. Less host specific parasites such as Gonocerca phycidis (Digenea) and Tetraphyllidea indet. (Cestoda) occurred at low rates of infection. The parasite fauna of this bathyal fish can be described as predominantly adult and host specific, with larval and less host specific components. A total of 16 different food groups were identified, most of them of benthic origin or associated with the benthopelagial. The predominant prey organisms belonged to the Crustacea (e.g., Copepoda, Gammaridea, Amphipoda and Isopoda), which serve as main parasite vectors for H. macrochir. This deep-sea fish seems to follow a general pattern of fish parasites in the deep sea, with most isolated parasites belonging to the digeneans, nematodes and a cestode. The parasite composition is caused by the narrow depth range of the species and the restricted distribution of the fish family Halosauridae. The species richness was found to be lower than other demersal fish from the deep sea and shallow waters, however, higher than those from deep-sea fish living in the pelagial.

  14. Chronic aquatic effect assessment for the fungicide azoxystrobin.

    PubMed

    van Wijngaarden, Rene P A; Belgers, Dick J M; Zafar, Mazhar I; Matser, Arrienne M; Boerwinkel, Marie-Claire; Arts, Gertie H P

    2014-12-01

    The present study examined the ecological effects of a range of chronic exposure concentrations of the fungicide azoxystrobin in freshwater experimental systems (1270-L outdoor microcosms). Intended and environmentally relevant test concentrations of azoxystrobin were 0 µg active ingredient (a.i.)/L, 0.33 µg a.i./L, 1 µg a.i./L, 3.3 µg a.i./L, 10 µg a.i./L, and 33 µg a.i./L, kept at constant values. Responses of freshwater populations and community parameters were studied. During the 42-d experimental period, the time-weighted average concentrations of azoxystrobin ranged from 93.5% to 99.3% of intended values. Zooplankton, especially copepods and the Daphnia longispina group, were the most sensitive groups. At the population level, a consistent no-observed-effect concentration (NOEC) of 1 µg a.i./L was calculated for Copepoda. The NOEC at the zooplankton community level was 10 µg azoxystrobin/L. The principle of the European Union pesticide directive is that lower-tier regulatory acceptable concentrations (RACs) are protective of higher-tier RACs. This was tested for chronic risks from azoxystrobin. With the exception of the microcosm community chronic RAC (highest tier), all other chronic RAC values were similar to each other (0.5-1 µg a.i./L). The new and stricter first-tier species requirements of the European Union pesticide regulation (1107/2009/EC) are not protective for the most sensitive populations in the microcosm study, when based on the higher tier population RAC. In comparison, the Water Framework Directive generates environmental quality standards that are 5 to 10 times lower than the derived chronic RACs. PMID:25196149

  15. Food web effects of titanium dioxide nanoparticles in an outdoor freshwater mesocosm experiment.

    PubMed

    Jovanović, Boris; Bezirci, Gizem; Çağan, Ali Serhan; Coppens, Jan; Levi, Eti E; Oluz, Zehra; Tuncel, Eylül; Duran, Hatice; Beklioğlu, Meryem

    2016-09-01

    Over the course of 78 days, nine outdoor mesocosms, each with 1350 L capacity, were situated on a pontoon platform in the middle of a lake and exposed to 0 μg L(-1) TiO2, 25 μg L(-1) TiO2 or 250 μg L(-1) TiO2 nanoparticles in the form of E171 TiO2 human food additive five times a week. Mesocosms were inoculated with sediment, phytoplankton, zooplankton, macroinvertebrates, macrophytes and fish before exposure, ensuring a complete food web. Physicochemical parameters of the water, nutrient concentrations, and biomass of the taxa were monitored. Concentrations of 25 μg L(-1) TiO2 and 250 μg L(-1) TiO2 caused a reduction in available soluble reactive phosphorus in the mesocosms by 15 and 23%, respectively, but not in the amount of total phosphorus. The biomass of Rotifera was significantly reduced by 32 and 57% in the TiO2 25 μg L(-1) and TiO2 250 μg L(-1) treatments, respectively, when compared to the control; however, the biomass of the other monitored groups-Cladocera, Copepoda, phytoplankton, macrophytes, chironomids and fish-remained unaffected. In conclusion, environmentally relevant concentrations of TiO2 nanoparticles may negatively affect certain parameters and taxa of the freshwater lentic aquatic ecosystem. However, these negative effects are not significant enough to affect the overall function of the ecosystem, as there were no cascade effects leading to a major change in its trophic state or primary production. PMID:26901391

  16. [Spatial and temporal variation in diet composition of invertivore fishes in a tropical stream, Venezuela].

    PubMed

    Ortaz, Mario; Martín, Ricardo; López-Ordaz, Adriana

    2011-09-01

    Invertivores fishes are an important component of neotropical streams and they represent a link between aquatic invertebrates and piscivorous species. This study evaluated the breadth diet and interspecific food overlap of nine invertivores fish species during three consecutive hydrological phases: falling (December/07, January/08, February/08 and March/08), low (April/08) and rising waters (June/08), in two sections of a Venezuelan neotropical stream, which were located at different elevation, high watershed (HW) and low watershed (LW). The fishes were collected with a beach seine (5mm mesh) between 8:00 and 11:00 hours. The diet of each species was evaluated using an index of relative importance (IRI), which includes as variables the number, weight and occurrence frequency of food items consumed. The Levin' index (B ) and Morisita (IM) were used to estimate the breadth diet and interspecific food overlap, respectively. All estimations were made using the numeric proportion of preys. Nine fish species were captured, eight Characiformes, of which three were captured in HW (Knodus deuteronoides, Creagrutus bolivari and C. melasma) and five in LW (Thoracocharax stellatus, Moenkhausia lepidura, Cheirodon pulcher, Ctenobrycon spilurus and Aphyocharax alburnus), and one Cyprinodontiformes (Poecilia reticulata), which was also found in HW. In HW aquatic insects were the main resource consumed by fishes while plant material and terrestrial arthropods were secondary resources. In LW the fishes ingested all of these items in addition to zooplankton (Copepoda, Cladocera and larval stages of Decapoda). However, there was a temporal replacement with a predominance of zooplankton in falling and low water. In general, the breadth diet decreased during the falling water in both sections and increased in rising water. However, the average breadth diet was higher in HW. The interspecific food overlap was high in HW while low values were more frequent in LW and its temporal

  17. Genetic diversity among the Eurytemora affinis species complex in the Scheldt estuary and its tributaries using ISSR-PCR marker assay

    NASA Astrophysics Data System (ADS)

    Gasmi, S.; Ferval, M.; Pelissier, C.; D'Amico, F.; Maris, T.; Tackx, M.; Legal, L.

    2014-05-01

    As an estuary being restored, the Scheldt (Belgium/The Netherlands) offers an interesting setting to study the response of organisms and ecosystems to changing conditions. This study specifically deals with this with regard to the spatio-temporal distribution and possible genetic differentiation among the species complex Eurytemora affinis (copepoda, calanoida). Until the 1990s, E. affinis typically occurred downstream the Scheldt estuary (Belgium/The Netherlands). In parallel to water quality improvement, E.affinis has recently also occurred upstream the estuary and in some of the tributaries. This paper aims to assess the origin of the copepod sibling species complex E. affinis occurring upstream the Scheldt estuary through genetic characterization. Using the Inter Simple Sequence Repeat (ISSR) technique, we explored genetic pools of the E. affinis complex in three Scheldt localities (downstream, middle-estuary and upstream) and two of its tributaries. Four ISSR primers produced 75 polymorphic loci. Bayesian and hierarchical analysis revealed different but close genetic entities in both down and upstream localities. The middle-estuary individuals were genetically a composite mix of downstream and upstream populations (84% from downstream and 16% from upstream). A distinctive separation of the tributaries and the main Scheldt stream populations suggests that two fully independent genetic pools are present. It is of note that the tributaries showed a lack of genetic subdivision, that upstream and downstream E. affinis populations are closely related, and that the downstream population is most likely at the origin of the upstream one, which implies the necessity to guarantee sufficient oxygen concentration levels throughout the estuarine continuum to guarantee the presence of this species upstream. The results of the ISSR technique are discussed in comparison with genetic studies on E. affinis using COI barcoding.

  18. Feeding ecology of the early life-history stages of two dominant gobiid species in the headwaters of a warm-temperate estuary

    NASA Astrophysics Data System (ADS)

    Wasserman, Ryan J.

    2012-08-01

    The diet and population structure of larval and early juvenile Glossogobius callidus and Redigobius dewaali (Gobiidae) were examined from the headwater region of the permanently open Great Fish Estuary along the south-east coast of southern Africa. Stomach contents of five selected size classes were sorted and identified to the lowest possible taxonomic level for each goby species. Using % Index of Relative Importance values, ontogenic shifts and dietary breadth were determined for each species as was dietary overlap between species. Numerically, both gobiid species showed similar temporal and spatial trends. Seasonal differences in catches were evident, although no numerical differences across sampled sites were found. A large degree of dietary overlap was found between the two species. The zooplanktonic diet showed a greater degree of ontogenic shift in R. dewaali than G. callidus, although similar trends were found for both. In both goby species, Calanoid sp. (Copepoda) generally decreased in importance across size classes, being the most important in the smallest size class whilst Corophium sp. (Amphipoda) increased in importance across size classes, being the least important at the smallest size classes. For both G. callidus and R. dewaali, Insecta contributed significantly to at least one of the five size classes. The larger size classes showed the least dietary overlap and the highest niche breadth. In addition, as is the case in many gobiids worldwide, the larger size classes of both sampled gobiid species consumed a broader prey size range. In conclusion, dietary overlap was largely similar between the young gobiids, suggesting that either food resources are not limiting, or niche separation is attributed to differences in foraging strategies. Ontogenic dietary shifts were however present for both gobiids with regard to prey items and prey size, suggesting a greater degree of foraging niche separation in adults of the species.

  19. Macroevolutionary patterns of sexual size dimorphism in copepods.

    PubMed

    Hirst, Andrew G; Kiørboe, Thomas

    2014-09-22

    Major theories compete to explain the macroevolutionary trends observed in sexual size dimorphism (SSD) in animals. Quantitative genetic theory suggests that the sex under historically stronger directional selection will exhibit greater interspecific variance in size, with covariation between allometric slopes (male to female size) and the strength of SSD across clades. Rensch's rule (RR) also suggests a correlation, but one in which males are always the more size variant sex. Examining free-living pelagic and parasitic Copepoda, we test these competing predictions. Females are commonly the larger sex in copepod species. Comparing clades that vary by four orders of magnitude in their degree of dimorphism, we show that isometry is widespread. As such we find no support for either RR or for covariation between allometry and SSD. Our results suggest that selection on both sexes has been equally important. We next test the prediction that variation in the degree of SSD is related to the adult sex ratio. As males become relatively less abundant, it has been hypothesized that this will lead to a reduction in both inter-male competition and male size. However, the lack of such a correlation across diverse free-living pelagic families of copepods provides no support for this hypothesis. By comparison, in sea lice of the family Caligidae, there is some qualitative support of the hypothesis, males may suffer elevated mortality when they leave the host and rove for sedentary females, and their female-biased SSD is greater than in many free-living families. However, other parasitic copepods which do not appear to have obvious differences in sex-based mate searching risks also show similar or even more extreme SSD, therefore suggesting other factors can drive the observed extremes. PMID:25100692

  20. A comparative study on mesozooplankton abundance and diversity between a protected and an unprotected coastal area of Andaman Islands.

    PubMed

    Pillai, Honey U K; Jayalakshmy, K V; Biju, A; Jayalakshmi, K J; Paulinose, V T; Devi, C B L; Nair, V R; Revichandran, C; Menon, N R; Achuthankutty, C T; Panampunnayil, S U

    2014-06-01

    The study was carried out to understand the variability in phytoplankton production (Chlorophyll a) and mesozooplankton diversity from two different shallow coastal regions of south Andaman viz. Port Blair Bay (PBB), the only real urban area among the islands and Mahatma Gandhi Marine National Park, a Marine Protected Area (MPA) at Wandoor. Seasonal sampling was carried out during the Northeast monsoon (NEM--November 2005), Intermonsoon (IM--April 2006), and Southwest monsoon (SWM--August 2006). Significant (P < 0.05) seasonal variation was observed in the environmental variables at both the regions. Higher average chlorophyll a (Chl. a) and mesozooplankton standing stock were observed at PBB compared to MPA, but the seasonal variation observed was marginal at both the study areas. Chl. a showed a steep increasing gradient from outer to the inner regions of the PBB. The number of zooplankton taxa recorded at both areas was quite similar, but marked differences were noticed in their relative contribution to the total abundance. Eventhough the Copepoda dominated at both the areas, the non-copepod taxa differed significantly between the regions. Dominance of carnivores such as siphonophores and chaetognaths were noticed at PBB, while filter feeders such as appendicularians and decapod larvae were more abundant at MPA. A total of 20 and 21 copepod families was recorded from PBB and MPA, respectively. Eleven species of chaetognaths were observed as common at both areas. Larval decapods were found to be predominant at MPA with 20 families; whereas, at PBB, only 12 families were recorded. In the light of the recent reports on various changes occurring in the coastal waters of the Andaman Islands, it is suspected that the difference in Chl. a as well as the mesozooplankton standing stock and community structure observed between the two study areas may be related to the various anthropogenic events influencing the coastal waters. PMID:24729177

  1. DNA barcoding of Arctic Ocean holozooplankton for species identification and recognition

    NASA Astrophysics Data System (ADS)

    Bucklin, Ann; Hopcroft, Russell R.; Kosobokova, Ksenia N.; Nigro, Lisa M.; Ortman, Brian D.; Jennings, Robert M.; Sweetman, Christopher J.

    2010-01-01

    Zooplankton species diversity and distribution are important measures of environmental change in the Arctic Ocean, and may serve as 'rapid-responders' of climate-induced changes in this fragile ecosystem. The scarcity of taxonomists hampers detailed and up-to-date monitoring of these patterns for the rarer and more problematic species. DNA barcodes (short DNA sequences for species recognition and discovery) provide an alternative approach to accurate identification of known species, and can speed routine analysis of zooplankton samples. During 2004-2008, zooplankton samples were collected during cruises to the central Arctic Ocean and Chukchi Sea. A ˜700 base-pair region of the mitochondrial cytochrome oxidase I (mtCOI) gene was amplified and sequenced for 82 identified specimens of 41 species, including cnidarians (six hydrozoans, one scyphozoan), arthropod crustaceans (five amphipods, 24 copepods, one decapod, and one euphausiid); two chaetognaths; and one nemertean. Phylogenetic analysis used the Neighbor-Joining algorithm with Kimura-2-Parameter (K-2-P) distances, with 1000-fold bootstrapping. K-2-P genetic distances between individuals of the same species ranged from 0.0 to 0.2; genetic distances between species ranged widely from 0.1 to 0.7. The mtCOI gene tree showed monophyly (at 100% bootstrap value) for each of the 26 species for which more than one individual was analyzed. Of seven genera for which more than one species was analyzed, four were shown to be monophyletic; three genera were not resolved. At higher taxonomic levels, only the crustacean order Copepoda was resolved, with bootstrap value of 83%. The mtCOI barcodes accurately discriminated and identified known species of 10 taxonomic groups of Arctic Ocean holozooplankton. A comprehensive DNA barcode database for the estimated 300 described species of Arctic holozooplankton will allow rapid assessment of species diversity and distribution in this climate-vulnerable ocean ecosystem.

  2. Feeding activity and influence of intraspecific competition on zooplankton communities by jundiá (Rhamdia quelen Quoy and Gaimard, 1824) in laboratory.

    PubMed

    Brandão-Gonçalves, L; Sebastien, N Y

    2013-11-01

    Experiments were designed to determine if the juvenile forms of jundia (Rhamdia quelen) exhibit selectivity feeding on zooplanktonic organisms and the influence of intraspecific competition on the diet. The fish were maintained in 5000-L containers, and after seven days from birth, they were acclimated in experimental units with different densities and supplied with water containing plankton (natural), where they remained for 24 h in the environment with food. In the first seven days at densities of 5 and 10 fish.L-1, the fish selected the Rotifera more intensely, and at densities of 20 and 40 fish.L-1, the Cladocera were more selected. At 14 days of age, the Cladocera were the most selected for all densities of fish. At 21 days of age, the juvenile forms of jundia maintained a preference for Cladocera, and there was an increase in the capture of Copepoda at a density of 40 fish.L-1. At 28 days of age, the Cladocera were the most captured at densities of 5 to 20 fish.L-1, and the consumption of copepods increased at a density of 40 fish.L-1. The juvenile forms of Rhamdia quelen showed a high feeding preference for Cladocera at all the ages tested (7, 14, 21 and 28 days), but the density of fish per litre influenced the capture of the preferential food. This study showed that the juvenile forms of jundia had a more rapid response to the presence of food at densities of more than 10 fish.L-1, and that at higher densities the fish decreased interactions of territorial defense and formed schools, which allowed the foraging of zooplanktonic organisms, larger in size, more agile and of greater energy gain, such as the Cladocera and copepods. PMID:24789392

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

    NASA Astrophysics Data System (ADS)

    Kirchner, M.

    1995-03-01

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

  4. Mining pollution and the diet of the purple-striped Gudgeon Mogurnda Mogurnda Richardson (Eleotridae) in the Finniss River, Northern Territory, Australia

    SciTech Connect

    Jeffree, R.A.; Williams, N.J.

    1980-01-01

    During the dry season of 1974, collections of the purple-striped Gudgeon Mogurnda Mogurnda were taken from the Finniss River of the Northern Territory; during the wet season, this river receives acidic and metallic pollutants from the formerly mined area of Rum Jungle. The fish consumed a great variety of foods, with high abundances of dytiscidae, chironomidae, ceratopogonidae, trichoptera, odonata, copepoda, decapoda, and pisces. For no food was there a significant regression against habitat descriptors in both of the zones; this emphasizes that pollution effects are more complex than simply depressing or raising the abundances of the dietary species. Five foods were more abundant in the diets of the polluted zone, and three in those of the unpolluted zone. The dietary abundances of two foods, both crustacean, increased in the polluted zone, compared to the unpolluted zone, through the dry season. Two categories of foods: (1) those obtaining oxygen directly from the atmosphere or via a film or bubble of air; and (2) the converse set (aquatic respirers), were contrasted for their usefulness in distinguishing between the zones, by both hierarchical agglomerative and discriminant function analyses. One collection from the polluted zone was reclassified as unpolluted on the basis of its grouping behaviour. The relevance for pollution studies of dietary analysis of euryphagous fish, rather than sampling aquatic fauna directly, is discussed in terms of food substitution, switching, strategies for abundance and recovery by the fauna, and possible effects of the pollutants on the fish as an intervening collector. Downstream patterns of abundance of the invertebrate fauna in this study are broadly similar to those of other studies in which such chemically diverse metals as Pb, Zn, and Cu are the pollutants, but there are differences for some faunal components.

  5. Structure of the parasite infracommunity of Sciades proops from the Japaratuba River Estuary, Sergipe, Brazil.

    PubMed

    Carvallho, R P S; Takemoto, R M; Melo, C M; Jeraldo, V L S; Madi, R R

    2015-11-01

    The catfish species Sciades proops inhabits muddy estuaries and shallow brackish lagoons, as well as freshwater. For these reasons, it is believed that this species may act as an intermediate, definitive and paratenic host in the life cycle of many parasites. From November 2010 to November 2011 and from August 2012 to July 2013, a total of 126 specimens of Sciades proops from the estuarine region of the Japaratuba River in the state of Sergipe, Brazil, were examined for parasites, of which 84.13% were infected by at least one species: Ergasilus sp. (Copepoda) (Prevalence P = 77.78%, Mean of Intensity MI = 10.08 ± 15.48, Mean Abundance MA = 14.27 ± 7.48) in the gills, Contracaecum sp. (P = 23.02%, MI = 20.59 ± 80.58, MA =39.12 ± 4.47) in the general cavity, Procamallanus sp. (P = 0.79%, MI = 1, MA = 0.01 ± 0.09), Raphidascaroides sp. (P = 2.31%, MI = 1.33 ± 0.58, MA = 0.33 ± 0.22) and Cuccullanus sp. (Nematoda) (P = 0.79%, MI = 1, MA = 0.01 ± 0.09) in the intestine, Ancyrocephalinae (Monogenea) (P = 0.79%, MI = 1, MA = 0.01 ± 0.09) in the gills, Pseudoacanthostomumpanamense (P = 1.59%, MI = 9.00 ± 8.49, MA = 0.14 ± 1.36) in the intestine, Clinostomum sp. (P = 1.59%, MI = 17.50 ± 23.33, MA = 0.29 ± 3.03) on the body surface and two unidentified metacercariae, referred to as Metacercaria 1 (P = 0.79%; IM = 1, MA = 0.01 ± 0.09) and Metacercaria 2 (Digenea) (P = 0.79%, MI = 7, MA = 0.06 ± 0.62) in the swim bladder. Ergasilus sp. was the dominant species and thus classified as core, with Contracaecum sp. as the satellite and other species as secondary species. The spatial distribution of infection with Ergasilus sp. and Contracaecum sp. showed a typical pattern of aggregate distribution. The sex of the host did not influence parasitic infections, but infection with Ergasilus sp. showed a positive and significant correlation with biometric and epidemiologic parameters, whereas infection with Contracaecum sp. was correlated only with prevalence and abundance

  6. Spring evolution of Pseudocalanus spp. abundance on Georges Bank based on molecular discrimination of P. moultoni and P. newmani1

    NASA Astrophysics Data System (ADS)

    Bucklin, Ann; Guarnieri, Maria; McGillicuddy, Dennis J.; Sean Hill, R.

    The planktonic copepod sibling species Pseudocalanus moultoni and P. newmani (Crustacea, Copepoda) are abundant in waters over Georges Bank from late winter until mid-summer and are thought to reproduce throughout this period. The two species cannot be reliably distinguished using morphological characters, but are readily identified and distinguished by simple, rapid, and inexpensive molecular protocols based on sequence variation of mitochondrial DNA (mtDNA). DNA sequence variation of a portion of the mitochondrial cytochrome oxidase I (mtCOI) confirmed the presence of P. moultoni and P. newmani on Georges Bank; the mtCOI sequences were used to design species-specific oligonucleotide primers for use in a competitive multiplexed species-specific polymerase chain reaction (PCR). Species-specific PCR was used to determine the relative abundances of the two species in sub-samples of zooplankton collections from US GLOBEC Georges Bank Study Broadscale Surveys from February to June, 1997. Based on monthly visualizations, we inferred the spring evolution of the two species' distributions and abundances on Georges Bank. Both species' overall abundances increased from February to May or June: maximum abundance of P. moultoni was 38,061 m -2 in surface waters on the crest of Georges Bank in June; maximum abundance of P. newmani was 13,854 m -2 in subsurface waters on the Northeast Peak in April. The Peak in distribution of P. moultoni shifted from Georges Basin in April, to the northern edge of the Bank in May, to the center of the Bank in June. In contrast, P. newmani was more abundant to the south and east of the Bank. Beginning in April, P. newmani occurred on the Bank but was less abundant and less widely-distributed than P. moultoni; P. newmani abundance peaked in May and declined somewhat in June. Females of the species differed in their patterns of distribution and abundance, with P. moultoni always the more abundant species on the crest of the Bank. The spring

  7. Observing copepods through a genomic lens

    PubMed Central

    2011-01-01

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

  8. Zooplankton of West Madagascar

    NASA Astrophysics Data System (ADS)

    Bemiasa, John; Remanevy, Sitraka

    2014-05-01

    During six week survey (August - October 2009) in Western and Northern coast of Madagascar, the R/V 'Dr. Fridtjof Nansen' has carried out a study of the pelagic ecosystem. In collaboration with Agulhas & Somali Current Large Marine Ecosystems project (ASCLME) and South West Indian Ocean Fisheries Project (SWIOFP), the aim of the survey was to establish the physical, chemical and biological characteristics of the Western Madagascar shelf region as a whole. Zooplankton samples were collected with Hydrobios Multinet at all environmental stations ranging from 200 m depth to the surface. The Multinet was equipped with 5 nets for depth-stratified sampling. The nets were fitted with 180 µm mesh size and the water flow through the nets was measured. The Multinet was deployed and retrieved at a rate of ~ 1.5 m per second and was obliquely hauled. The five nets were triggered at the pre-selected depth intervals 0-25m, 25-50m, 50-80m, 80-120m and 120-200m. All samples were stored in marked bottles and preserved with buffered formaldehyde of 4% for further analysis. As results,the zooplankton abundance was influenced by physico-chemical factors. During the study period 34 Family of zooplankton were identified which are dominated by Copepoda (58,69%) followed by Radiolaria (12,06%), Appendicularia (6,47%), Sagitta (5,11%), Larvae (4,57%), Ostracoda (3,13%), pelagic Foraminifera (2,15%). Family of zooplankton with abundance <1% were also recorded, namely Salpidae (0,94%), Euphausiacea (0,44%), Tintinnidae (0,39%), Annélidae Polychètes (0,34%), Mysidacea (0,21%), Ptéropodae (0,13%). Highest number of zooplankton were found at the depth below the maximum of fluorescence during the day. Copepods distribution depends on site and depth. During this study, the number of identified species is always superior to 50 for all sampling sites. The findings of the present study will help to improve the scientific knowledge of the marine ecosystem of the west coast of Madagascar.

  9. Modern and fossilized biological communities from sediments of Bolshoy Harbei lake (Bolshezemelskaya tundra, Russia) and their response to climate change

    NASA Astrophysics Data System (ADS)

    Tumanov, Oleg; Nazarova, Larisa; Fefilova, Elena; Baturina, Maria; Loskutova, Olga; Frolova, Larisa; Palagushkina, Olga

    2013-04-01

    High-altitude regions are subjected to the threats of global warming. During the last decade the depth of seasonal melting of permafrost in Northern Russia, significantly increased. Investigation of lake sediments from polar regions has an extreme importance for understanding of the modern environmental processes and their influence on northern ecosystems and biological diversity of these regions. Invertebrate communities are used for diagnostic of lake ecosystems because they have a great sensitivity to climatic changes (Andronnikova, 1996; Lazareva, 2008; O'Brien et al., 2005). The data can be used as well as a basis for inference models for reconstruction of the paleoclimatic conditions. Chironomid-based, Cladocera-based and diatom models have successfully been developed (Nazarova et al., 2008, 2011; Self et al., 2011) and can be used for precise paleotemperature reconstructions (Kienast et al., 2011). In summer 2012, we investigated complex of Kharbei lakes, located in the interfluve of Korotaiha and Bolshaya Rogovaya rivers in the east side of Bolshezemelskaya tundra, Russia (67°33'22″ N, 62°53'23″ E). Six different lakes were investigated using modern hydrobiological and palaeoecological methods. In total 9 cores were obtained, cut, dated and further investigated using sedimenthological, geochemical, and paleobiological methods. The standard hydrobiological methods have shown that the modern zooplankton communities did not change significantly during the last 40 years. Taxonomic composition and structure of planktonic communities didn't change, except for appearance of crustaceans Polyarthra euryptera and Daphnia cucullata. In planktonic communities of Bolshoy Harbei lake we revealed 39 species and forms of Rotifera, 19 - Cladocera and 11 - Copepoda. In zoobenthic communities we registered 24 taxonomical groups characteristic for large tundra lakes of the North East of Russia. Chironomids and Oligochaeta are dominant groups of invertebrates. 103 taxa of

  10. A “Rosetta Stone” for metazoan zooplankton: DNA barcode analysis of species diversity of the Sargasso Sea (Northwest Atlantic Ocean)

    NASA Astrophysics Data System (ADS)

    Bucklin, Ann; Ortman, Brian D.; Jennings, Robert M.; Nigro, Lisa M.; Sweetman, Christopher J.; Copley, Nancy J.; Sutton, Tracey; Wiebe, Peter H.

    2010-12-01

    Species diversity of the metazoan holozooplankton assemblage of the Sargasso Sea, Northwest Atlantic Ocean, was examined through coordinated morphological taxonomic identification of species and DNA sequencing of a ˜650 base-pair region of mitochondrial cytochrome oxidase I (mtCOI) as a DNA barcode (i.e., short sequence for species recognition and discrimination). Zooplankton collections were made from the surface to 5,000 meters during April, 2006 on the R/V R.H. Brown. Samples were examined by a ship-board team of morphological taxonomists; DNA barcoding was carried out in both ship-board and land-based DNA sequencing laboratories. DNA barcodes were determined for a total of 297 individuals of 175 holozooplankton species in four phyla, including: Cnidaria (Hydromedusae, 4 species; Siphonophora, 47); Arthropoda (Amphipoda, 10; Copepoda, 34; Decapoda, 9; Euphausiacea, 10; Mysidacea, 1; Ostracoda, 27); and Mollusca (Cephalopoda, 8; Heteropoda, 6; Pteropoda, 15); and Chaetognatha (4). Thirty species of fish (Teleostei) were also barcoded. For all seven zooplankton groups for which sufficient data were available, Kimura-2-Parameter genetic distances were significantly lower between individuals of the same species (mean=0.0114; S.D. 0.0117) than between individuals of different species within the same group (mean=0.3166; S.D. 0.0378). This difference, known as the barcode gap, ensures that mtCOI sequences are reliable characters for species identification for the oceanic holozooplankton assemblage. In addition, DNA barcodes allow recognition of new or undescribed species, reveal cryptic species within known taxa, and inform phylogeographic and population genetic studies of geographic variation. The growing database of "gold standard" DNA barcodes serves as a Rosetta Stone for marine zooplankton, providing the key for decoding species diversity by linking species names, morphology, and DNA sequence variation. In light of the pivotal position of zooplankton in ocean

  11. Abyssal macrofauna of the Kuril-Kamchatka Trench area (Northwest Pacific) collected by means of a camera-epibenthic sledge

    NASA Astrophysics Data System (ADS)

    Brandt, A.; Elsner, N. O.; Malyutina, M. V.; Brenke, N.; Golovan, O. A.; Lavrenteva, A. V.; Riehl, T.

    2015-01-01

    Abyssal macrofaunal composition of 21 epibenthic sledge hauls from twelve stations taken in the Kuril-Kamchatka Trench (KKT) and at the adjacent abyssal plain, Northwest Pacific, is presented. Sampling with the fine meshed epibenthic sledge yielded higher abundances and species richness than was reported from previous expeditions from board of RV Vityaz. In total 84,651 invertebrates were sampled with RV Sonne between July and September of 2012 (31,854 invertebrates if standardised for 1000 m2 trawled distances) from 41 taxa of different taxonomic ranks (15 phyla, 28 classes, 7 orders) were sampled from a trawled area of 53,708 m² and have been analyzed. Few taxa were frequent and most taxa were rare in the samples, twelve taxa occurred with more than 1% frequency. Of these, the Polychaeta were most abundant followed by the benthic Copepoda and Isopoda. Total numbers of individuals varied between stations and were highest with 4238 individuals at station 2-10 close to the KKT in 4865 m depth and lowest with 374 individuals at station 6-11 in 5305 m depth. At this station also the lowest number of taxa occurred (18 taxa) while the highest number occurred with 31 taxa at station 3-9 in 4991 m depth. Numbers of individuals decreased with increasing depth between 4830 and 5780 m. Crustaceans of the superorder Peracarida were one of the dominating taxa with four orders occurring frequently in most samples. In total, Isopoda were most important and occurred with 59% of all peracarid orders sampled, followed by Amphipoda with 21%, Tanaidacea with 11%, Cumacea with 9%, and Mysidacea with <1%. The communities of the stations (and hauls) of the KKT abyssal area differ in terms of taxon composition from each other. A cluster analysis (nMDS) performed for all sampled stations revealed no clear pattern of community similarity between stations or hauls. All hauls close to the trench (2-9 and 2-10 close to the eastern slope of the KKT; and 3-9 and 4-3 at the western slope) were

  12. Comparison of physico-chemical parameters and zooplankton diversity in two perennial ponds at Aligarh, India.

    PubMed

    Parveen, Saltanat; Abdel Mola, Hesham R

    2013-07-01

    Investigations were carried out on the diversity of zooplankton in relation to physico-chemical parameters of two perennial ponds (Chautal Pond and Medical Pond) of Aligarh, India. Thirty nine species of holoplankton were identified belonging to copepoda (2 species), rotifera (28 species), cladocera (6 species) and protozoa (3 species). Other forms; like as meroplankton (insects) and tychoplankton (nematodes and ostracodes) were also recorded. Higher values of physico-chemical parameters and low zooplankton diversity were recorded in the Chautal Pond, whereas low values of physico-chemical parameters and high diversity were recorded in the Medical Pond. Ostracods considered to be the most dominant group in Medical Pond (32.16% of the total zooplankton) while Cladocerans are considered to be the most dominant group in Chautal Pond (38.83% of the total zooplankton). Rotifera contributed more in Medical Pond (16.42%) as compared to Chautal Pond (15.81%). Five species of Brachionus was recorded during study. Out of five, four Brachionus species were recorded in Chautal Pond while only two species were recorded in Medical pond. This indicates that Chautal Pond is more eutrophic than Medical pond. In addition, higher carbon dioxide values (37-105 mg l(-1)), low dissolved oxygen (0.7-3.3 mg I(-1)) and higher electrical conductivity values (1069-1691 mg l(-1)) were also indicative of eutrophic nature of Chautal Pond. Present study also revealed that total zooplankton species, species richness and diversity indices (Evenness, Shannon-Winner and Simpson) were comparatively higher in Medical pond. The rotifer species Philodina roseola (146 Org. l(-1)) and Monstyla closterocerca (109 Org. l(-1)) was dominated in Medical Pond while the rotifers Brachionus urceolaris (512 Org. l(-1)) and the cladocern species Ceriodaphnia cornuta (1540 Org. l(-1)) dominated in Chautal Pond during post-monsoon season. This might be due to the effect of rain water which played an important role in

  13. An Overview of Ecological Processes in the Rio de la Plata Estuary

    NASA Astrophysics Data System (ADS)

    Acha, M.; Mianzan, H.

    2005-05-01

    The Rio de la Plata, one of the most important estuarine environments in South America, is characterized by a salt-wedge regime. Large extension and shallow water depth make the estuary highly susceptible to atmospheric forcing. The estuary is a highly productive area, which sustain important artisanal and coastal fisheries in Uruguay and Argentina, mainly based on the whitemouth croaker, Micropogonias furnieri. The main goal of this paper is to summarize recent knowledge on this system, integrating physical, chemical and biological studies. This estuary is characterized by strong vertical salinity stratification, with marine waters (saltier and denser) penetrating deeper into the estuary along the bottom, while fresh waters advance ocean-ward on the surface, forming a salt wedge. The upstream reach of the salt wedge defines a bottom salinity fronts, whose location is controlled by the topography, a submerged shoal called Barra del Indio and at the opposite area, the convergence between the estuarine and marine waters define a surface salinity front. The convergence of water masses and the strong picnoclines at the head of the salt wedge produce the accumulation and retention of plankton, including the eggs of those fishes that concentrate here to spawn (e.g. Micropogonias furnieri and Brevoortia aurea) and even debris. High turbidity constrains here photosynthetic production and food chains are probably detritus based, supporting high densities of Acartia tonsa (Copepoda) and Neomysis americana (Mysid), both omnivorous species that complete its entire life-cycle within the estuary. In agreement, heterotophic microzooplankton is abundant. Moreover, high deposition of suspended matter support dense beds of the deposit feeding clams Mactra isabelleana. As soon as the water become less turbid, an extremely high chlorophyll signal is observed. The largest portion of the salt wedge regime (more than 200 km) is characterized by dense plankton aggregations below the

  14. Effects of structural marsh management and salinity on invertebrate prey of waterbirds in marsh ponds during winter on the Gulf Coast Chenier Plain

    USGS Publications Warehouse

    Bolduc, F.; Afton, A.D.

    2003-01-01

    . Furthermore, as predicted, an a priori MANOVA contrast indicated that biomass of a single invertebrate class adapted to low salinity (Oligochaeta, 200 to 999 ??m) was greater in ponds of IF marshes than in those of IO and IM marshes. A canonical correspondence analysis indicated that variation in salinity and O2 penetration best explained differences among sites that maximized biomass of the common invertebrate classes. Salinity was positively correlated with the silt-clay fraction, O2, and O2 penetration, and negatively correlated with water depth, sediment hardness, carbon, and C:N. Nematoda, Foraminifera, and Copepoda generally were associated with UM marsh ponds and high salinity, whereas other invertebrate classes were distributed among impounded marsh ponds and associated with lower salinity. Our results suggest that SMM and salinity have relatively small effects on invertebrate prey of wintering waterbirds in marsh ponds because they affect biomass of Nematoda and Oligochaeta, and few waterbirds consume these invertebrates. ?? 2003, The Society of Wetland Scientists.

  15. Food-web structure and trophodynamics of mesopelagic-suprabenthic bathyal macrofauna of the Algerian Basin based on stable isotopes of carbon and nitrogen

    NASA Astrophysics Data System (ADS)

    Fanelli, E.; Cartes, J. E.; Rumolo, P.; Sprovieri, M.

    2009-09-01

    The trophodynamics of mesopelagic (macrozooplankton/micronekton) and benthic boundary layer (suprabenthos=hyperbenthos) faunas from the Algerian Basin were characterized on a seasonal scale through stable carbon and nitrogen isotopic analyses of a total of 34 species and two broad taxa (Copepoda and Cumacea). This is the first study simultaneously focused on trophodynamics of deep-sea zooplankton and suprabenthos. Samples were collected southeast of Mallorca (Algerian Basin, Western Mediterranean), on the continental slope close to Cabrera Archipelago, at 650-780 m depths, ca. bi-monthly between August 2003 and June 2004. Mean δ 13C values of suprabenthos ranged from -21.1‰ ( Munnopsurus atlanticus) to -16.7‰ ( Cyclaspis longicaudata). Values of δ 15N ranged from 2.8‰ ( Lepechinella manco) to 9.9‰ (larvae of Gnathia sp.). The stable isotope ratios of suprabenthic fauna displayed a continuum of values, confirming a wide spectrum of feeding guilds (from filter feeders/surface deposit feeders to predators). According to the available information on diets for suprabenthic species, the highest annual mean δ 15N values were found for the hematophagous isopod Gnathia sp. parasite on fish (represented by Praniza larvae) and carnivorous amphipods (e.g. Rhachotropis spp., Nicippe tumida) consuming copepods, and the lowest δ 15N values were found for two cumaceans ( Cyclaspis longicaudata and Platysympus typicus) feeding on detritus. Assuming a 15N-enrichment factor of 2.5‰ and deposit feeders as baseline, we found three trophic levels in suprabenthic food webs. δ 13C ranges were particularly wide among deposit feeders (ranging from -21.8% to -17.3‰) and omnivores (from -20.5% to -18.8‰), suggesting exploitation of particulate organic matter (POM) of different characteristics. Our isotopic analyses revealed lower ranges of δ 13C and δ 15N for macrozooplankton/micronekton, compared with suprabenthos. δ 13C values of zooplankton taxa ranged from -21.1