|Scientific Name:||Apristurus exsanguis Sato, Nakaya & Stewart, 1999|
|Taxonomic Notes:||The genus Apristurus is one of the most taxonomically confused groups of sharks. Most species are superficially very similar and many have been poorly described. Sexual dimorphism in some species, and changes in body proportions with growth also complicate identification. There are 33 described species of Apristurus, plus at least four other potentially undescribed species from New Zealand. A. exsanguis is similar to, but separate from Apristurus sp. B from New Zealand (Paulin et al. 1989) and Apristurus sp. A. from Australia (Last and Stevens 1994).|
|Red List Category & Criteria:||Least Concern ver 3.1|
|Assessor(s):||Duffy, C. (SSG Australia & Oceania Regional Workshop, March 2003)|
|Reviewer(s):||Fowler, S., Cavanagh, R.D. & Kyne, P.M. (Shark Red List Authority)|
Although this is an endemic species collection records indicate it is widespread and probably continuously distributed over the mid to lower slope around New Zealand. The biology of all Apristurus species within the New Zealand Exclusive Economic Zone (EEZ) is very poorly known due to the uncertain taxonomy of the group. They appear to be most abundant below 1,000 m, and are the only sharks regularly taken in research trawls below 1,200 m on the Chatham Rise. As relatively little fishing occurs below 1,200 m depth a large part of these species’ populations may be effectively beyond fishing depths. Although the maximum recorded depth of A. exsanguis is 1,200 m there have been relatively few research trawls below this depth and it is possible that they occur deeper than this. There is also relatively little deepwater trawling effort in the northern part of the species distribution. This situation may change, however, as some fishing companies have conducted exploratory deepwater trips off northeast North Island.
|Range Description:||Apristurus exsanguis is endemic to New Zealand. It has been recorded from off Three Kings Islands, North and South Islands, southern Lord Howe Rise, Challenger Plateau, Hikurangi Trough, Chatham Rise and Campbell Plateau to about 54°S. Depth 573 to 1,200 m.|
|FAO Marine Fishing Areas:|
Pacific – southwest
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||There is no information on population size.|
|Current Population Trend:||Unknown|
|Habitat and Ecology:||The biology of all Apristurus species within the New Zealand Exclusive Economic Zone (EEZ) is very poorly known due to the uncertain taxonomy of the group. They appear to be most abundant below 1,000 m, and are the only sharks regularly taken in research trawls below 1,200 m on the Chatham Rise. A. exsanguis is a widespread mid to lower slope species. Probably bottom-living. Although its maximum recorded depth is 1,200 m there have been relatively few research trawls below this depth and it is possible that they occur deeper than this (Francis et al. 2002). Males and females mature between 650–700 mm total length. Reproduction is oviparous. The dark brown egg case is about 68 mm long and 29 mm wide. There is a slight constriction in the anterior third of the case, and its surface is entirely covered by fine fibers and fine longitudinal grooves. The edges of the egg case are flanged and end in horn-like processes with long coiled tendrils. Fecundity is unknown. Diet is probably similar to other Apristurus species (i.e., small bony fishes and caridean shrimps).|
|Major Threat(s):||Deepwater bottom trawling. As relatively little fishing occurs below 1,200 m and the species may occur in deeper water than this, a part of its population may be beyond current fishing depth (Anderson et al. 1998, Wetherbee 2000). There is also relatively little deepwater trawling effort in the northern part of the species distribution. This situation may change as deepwater fisheries expand.|
|Conservation Actions:||Currently no conservation measures in place.|
Anderson, O.F., Bagley, N.W., Hurst, R.J., Francis, M.P., Clark, M.R. and McMillan, P.J. 1998. Atlas of New Zealand fish and squid distributions from research bottom trawls. NIWA Technical Report 42. NIWA, Wellington. 303 pp.
Francis, M.P., Hurst, R.J., McArdle, B.H., Bagley, N.W., and Anderson, O.F. 2002. New Zealand demersal fish assemblages. Environmental Biology of Fishes 65: 215-234.
IUCN. 2003. 2003 IUCN Red List of Threatened Species. www.iucnredlist.org. Downloaded on 18 November 2003.
IUCN SSC Shark Specialist Group. Specialist Group website. Available at: http://www.iucnssg.org/.
Last, P.R. and Stevens, J.D. 2009. Sharks and Rays of Australia. Second Edition. CSIRO Publishing, Collingwood.
Nakaya, K. and Sato, K. 1999. Species grouping within the genus Apristurus (Elasmobranchii: Scyliorhinidae). In: B. Séret and J-Y Sire (eds) Proceedings of the 5th Indo-Pacific Fish Conference (Nouméa, 3-8 November 1997). Paris, Society Francaise d’Ichthyologie et Instutue de Recherches pour le Development: 307-320.
Paulin, C., Stewart, A., Roberts, C. and McMillan, P. 1989. New Zealand fish: a complete guide. Te Papa Press.
Sato, K., Nakaya, K. and Stewart, A.L. 1999. A new species of the deep-water catshark genus Apristurus from New Zealand waters (Chondrichthyes: Scyliorhinidae). Journal of the Royal Society of New Zealand 29(4): 325 – 335.
Wetherbee, B.M. 2000: Assemblage of deep-sea sharks on Chatham Rise, New Zealand. Fishery Bulletin 98: 189 – 198.
|Citation:||Duffy, C. (SSG Australia & Oceania Regional Workshop, March 2003). 2003. Apristurus exsanguis. The IUCN Red List of Threatened Species 2003: e.T41719A10547793.Downloaded on 24 October 2017.|
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