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Type: Article
Published: 2019-03-11
Page range: 361–372
Abstract views: 62
PDF downloaded: 2

Re-description of Azygokeras columbiae Koeller & Littlepage, 1976 (Calanoida: Aetideidae) and musculature of the male grasping antennule

National Institute of Water and Atmospheric Research, Private Bag 14901, Kilbirnie, Wellington 6241, New Zealand.
Department of Life Sciences, Natural History Museum, Cromwell Road, London SW7 5BD, U.K.
Crustacea Clausocalanoidea Augaptiloidea Centropagoidea Megacalanidae Bathypontiidae Canada benthopelagic

Abstract

Azygokeras columbiae from Bute Inlet, British Columbia, Canada, is re-described, correcting some details and adding information not available in the original description. Azygokeras columbiae is unique amongst male Aetideidae in having the right antennule modified for grasping but without a true knee joint (geniculation) between segments XX and XXI nor a hiatus in the musculature at this joint, typical of taxa with a geniculate male antennule. Male Azygokeras have wide pivot points and arthrodial membranes between segments XXI and XXII, XXIII and XXIV and XXV and XXVI that allow greater movement in several planes than in homologous segments of Euaugaptilus and Heterorhabdus. Modifications of the terminal antennular joints allow for extensive movement in several planes associated with a series of short muscles in segments XIX to XXVI. These muscles become progressively more massive from proximal to distal on the antennule and are paired with an antagonistic muscle also increasing in mass distally.

 

References

  1. Andronov, V.N. (1974) Phylogenetic relations of large taxa within the suborder Calanoida (Crustacea, Copepoda). Zoologichesky Zhurnal, 53, 1002–1012. [In Russian]

    Boxshall, G.A. (1985) The comparative anatomy of two copepods, a predatory calanoid and a particle feeding mormonilloid. Philosophical Transactions of the Royal Society, London, Series B, 311, 303–377.

    https://doi.org/10.1098/rstb.1985.0155

    Boxshall, G.A. & Halsey, S.H. (2004) An introduction to copepod diversity. The Ray Society, London, 966 pp.

    Boxshall, G.A. & Huys, R. (1998) The ontogeny and phylogeny of copepod antennules. Philosophical Transactions of the Royal Society, London, Series B. 353, 765–786.

    https://doi.org/10.1098/rstb.1998.0242

    Bradford-Grieve, J.M., Blanco-Bercial, L. & Boxshall, G.A. (2017) Revision of Family Megacalanidae (Copepoda: Calanoida). Zootaxa, 4229, 1–183.

    https://doi.org/10.11646/zootaxa.4229.1

    Bradford-Grieve, J.M. & Boxshall, G.A. (2019) Partial re-assessment of the family structure of the Clausocalanoidea (Copepoda: Calanoida) using morphological data. Zoological Journal of the Linnean Society, London, XX, 1–26.

    Bradford-Grieve, J.M., Boxshall, G.A. & Blanco-Bercial, L. (2014) Revision of basal calanoid copepod families, with a description of a new species and genus of Pseudocyclopidae. Zoological Journal of the Linnean Society, London, 171, 507–533.

    https://doi.org/10.1111/zoj12141

    Coleman, C.O. (2003) ‘Digital inking’: how to make perfect line drawings on computers. Organisms Diversity and Evolution, 14, 1–14.

    Huys, R. & Boxshall, G.A. (1991) Copepod evolution. The Ray Society, London, 468 pp.

    Koeller, P.A. & Littlepage, J.L. (1976) Azygokeras columbiae, a new genus and species of marine epibenthic copepod (Calanoida: Aetideidae) from British Columbia. Journal of the Fisheries Research Board of Canada, 33, 1547–1552.

    https://doi.org/10.1139/f76-194

    Markhaseva, E.L. (1996) Calanoid copepods of the family Aetideidae of the World. Proceedings of the Zoological Institute, Russian Academy of Sciences, St. Petersburg, 268, 331 pp.

    Markhaseva, E.L. & Renz, J. (2015) A new genus and species of Peniculoides (Copepoda, Calanoida) from deep waters of the North Atlantic with notes on Clausocalanidae definition. Crustaceana, 88, 1031–1047.

    https://doi.org/10.1163/15685403-00003467

    Markhaseva, E.L. & Schulz, K. (2006) Sensiava longiseta (Copepoda, Calanoida): a new genus and species from the abyss of the Weddell Sea. Zootaxa, 1368, 1–18.

    https://doi.org/10.11646/Zootaxa.1368.1

    Ohtsuka, S. & Huys, R. (2001) Sexual dimorphism in calanoid copepods: morphology and function. Hydrobiologia, 453/454, 441–466.

    https://doi.org/10.1023/A:1013162605809

    Pantin, C.F.A. (1964) Notes of microscopical technique for zoologists. University Press, Cambridge, 77 pp.

    Renz, J., Markhaseva, E.L. & Schulz, K. (2012) Ryocalanus antarcticus n. sp. (Crustacea: Copepoda)—first ryocalanid from the Southern Ocean. Proceedings of the Zoological Institute, Russian Academy of Sciences, 316 (2), 148–158.

    Renz, J., Markhaseva, E.L. & Schulz, K. (2013) Ryocalanus brasilianus sp. nov. (Crustacea: Copepoda, Calanoida), a new ryocalanoid from the South Atlantic and the segregation of Yrocalanus gen. nov. Zoosystematics and Evolution, 89 (2), 247–258.

    https://doi.org/10.1002/zoos.201300011

    Sars, G.O. (1905) List préliminaire des Calanoides recueillis pendant les campagnes de S.A.S. le Prince Albert de Monaco, avec diagnoses des genres et des espèces nouvelles (2e partie). Bulletin du Musée Océanographique de Monaco, 40, 1–24.

    Tanaka, O. (1956) Rare species of Copepoda Calanoida taken from the Izu region. Breviora, 64, 1–8.