Abstract
Gnathiid isopods collected from seamounts off northern New Zealand were examined. Two species of gnathiids were found, Caecognathia nieli sp. nov., and Gnathia sifae sp. nov. Caecognathia nieli sp. nov. is easily distinguished from all other known New Zealand gnathiid species in shape of the head, having an evenly rounded frontal border, and a fine bifid notch. Gnathia sifae sp. nov. is distinguished from all other New Zealand gnathiid species in having a distinct mediofrontal process on the cephalon, but no frontolateral processes. It is further clearly distinguished from the cooccurring species, Caecognathia nieli sp. nov., in having relatively larger eyes and of different shape, in the presence of lateral projections on the pereopods and in the shape of the appendix masculina.References
Bull, B., Doonan, I., Tracey, D. & Hart, A. (2001) Diel variation in spawning orange roughy (Hoplostethus atlanticus, Trachichthyidae) abundance over a seamount feature on the north-west Chatham Rise. New Zealand Journal of Marine and Freshwater Research, 35, 435–444.
Bruce, N.L. (2002) Tridentella rosemariae sp. nov. (Crustacea: Isopoda: Tridentellidae), from northern New Zealand waters. Crustaceana, 75 (2), 159–170.
Bruce, N.L. (2003) A new deep-water species of Natatolana (Crustacea: Isopoda: Cirolanidae) from the Chatham Rise, eastern New Zealand. Zootaxa, 265, 1–12.
Bruce, N.L. (2004a) New species of the Cirolana “parva-group” (Crustacea: Isopoda: Cirolanidae) from coastal habitats around New Zealand. Species Diversity, 9, 47–66.
Bruce, N.L. (2004b) Mexicope sushara sp. nov., the first New Zealand record of the isopod crustacean family Acanthaspidiidae (Asellota). Zootaxa, 489, 1–11.
Bruce, N.L. (2004c) Reassessment of the isopod crustacean Aega deshaysiana (Milne Edwards, 1840) (Cymothoida: Aegidae) — a world-wide complex of 21 species. Zoological Journal of the Linnean Society, 142 (2), 135–232.
Bruce, N.L. (2005) New Sphaeromatidae (Crustacea: Isopoda: Sphaeromatidea) from coastal and freshwater habitats in New Zealand. Zootaxa, 1002, 1–20.
Cohen, B.F. & Poore, G.C.B. (1994) Phylogeny and biogeography of the Gnathiidae (Crustacea: Isopoda) with descriptions of new genera and species, most from south-eastern Australia. Memoirs of the Museum of Victoria, 54, 271–397.
Dower, J.F. & Perry, R.I. (2001) High abundance of larval rockfish over Cobb Seamount, an isolated seamount in the Northeast Pacific. Fisheries Oceanography, 10, 268–274.
Holdich, D.M. & Harrison, K. (1980) The crustacean isopod genus Gnathia Leach from Queensland waters with descriptions of nine new species. Australian Journal of Marine and Freshwater Research, 31, 215–240.
Grutter, A.S., Lester, R.J.G. & Greenwood, J. (2000) Emergence rates from the benthos of the parasitic juveniles of gnathiid isopods. Marine Ecology Progress Series, 207, 123–127.
Just, J., & Wilson, G.D.F. (2004) Revision of the Paramunna complex (Isopoda: Asellota: Paramunnidae). Invertebrate Systematics, 18 (4), 377–466.
Kensley, B., Schotte, M. & Schilling, S. (2005) World list of marine, freshwater and terrestrial isopod crustaceans. Smithsonian Institution, Washington, DC, USA. Available from http://www.nmnh.si.edu/iz/isopod/ (accessed May 2005)
Klitgaard, A.B. (1997) The distribution and habitats in the North Atlantic of two gnathiid species (Crustacea, Isopoda) and their reproductive biology in the Denmark Strait and north of Iceland. Meddelelser om Grønland, Bioscience, 47, 1–32.
Koslow, J.A., Gowlett-Holmes, K., Lowry, J.K., O’Hara, T., Poore, G.C.B. & Williams, A. (2001) Seamount benthic macrofauna off southern Tasmania: Community structure and impacts of trawling. Marine Ecology Progress Series, 213, 111–125.
Merrin, K.L. (2004) Review of the deep-water asellote genus Notopais Hodgson, 1910 (Crustacea: Isopoda: Munnopsididae) with description of three new species from the south-western Pacific. Zootaxa, 513, 1–27.
Monod, T. (1926) Les Gnathiidæ. Essai monographique (Morphologie, Biologie, Systématique). Mémoires de la Société des Sciences Naturelles du Maroc, 13, 1–668.
Müller, H.-G. (1989a) Redescription of Gnathia sugashimaensis Nunomura (Crustacea: Isopoda) from Japan. Publications of the Seto Marine Biological Laboratory, 34, 25–30.
Müller, H.-G. (1989b) A new species of marine isopod of the genus Gnathia from the Fiji Islands, the South Pacific. Publications of the Seto Marine Biological Laboratory, 34, 31–35.
Nunomura, N. (1992) Marine Isopoda from Amakusa, Kyushu (II). Publications from the Amakusa Marine Biological Laboratory, 11, 59–71.
Nunomura, N. (1998) A new species of the gnathiid isopod crustacean from the sea off Sanriku, Northern Japan. Bulletin of the Toyama Science Museum, 21, 55–60.
Smit, N.J. & Davies, A.J. (2004) The curious life-style of the parasitic stages of gnathiid isopods. Advances in Parasitology, 58, 289–391.
Svavarsson, J. (2002) Gnathiidae (Crustacea, Isopoda) from the Andaman Sea, Thailand: new records and a new species. In: Bruce, N.L., Berggren, M. & Bussawarit, S. (Eds.), Proceedings of the International Workshop on the Crustacea in the Andaman Sea, Phuket Marine Biological Center, 29 November–20 December 1998, Phuket Marine Biological Center Special Publication, 23, Phuket Marine Biology Center, Phuket, pp. 149–156.
Svavarsson, J. & Gísladóttir, E. (2002) Elaphognathia korachaensis n. sp., a new gnathiid species (Crustacea, Isopoda) from Thailand. In: Bruce, N.L., M. Berggren & S. Bussawarit (Eds.), Proceedings of the International Workshop on the Crustacea in the Andaman Sea, Phuket Marine Biological Center, 29 November–20 December 1998, Phuket Marine Biological Center Special Publication, 23, Phuket Marine Biology Center, Phuket, pp. 157–164.
Svavarsson, J. & Jörundsdóttir, K. (2004) A new gnathiid species (Crustacea, Isopoda, Cymothoida) from Rodrigues, Mauritius, Indian Ocean. Journal of Natural History, 38, 3103–3111.
Tanaka, K. & Aoki, M. (1999) Spatial distribution patterns of the sponge-dwelling gnathiid isopod Elaphognathia cornigera (Nunomura) on an intertidal rocky shore of the Izu Peninsula, southern Japan. Crustacean Research, 28, 160–167.
Upton, N.P.D. (1987) Asynchronous male and female life cycles in the sexually dimorphic, harem-forming isopod Paragnathia formica (Crustacea: Isopoda). Journal of Zoology, 212, 667–690.