|Scientific Name:||Apristurus longicephalus|
|Species Authority:||Nakaya, 1975|
|Taxonomic Notes:||The genus Apristurus contains at least 32 described species and a relatively large number of potentially undescribed ones. Morphological conservatism and, until recently, a lack of objectively defined characters makes this one of the most taxonomically confused shark genera (Compagno 1984, Nakaya and Sato 1999).
Nakaya and Sato (1999) defined three species groups within Apristurus: the longicephalus-group (two species), brunneus-group (20 species) and spongiceps-group (10 species). The longicephalus-group is characterized by a long, narrow snout (prenarial length > 6.4% TL). A. longicephalus is readily distinguished from A. herklotsi, the other member of the group, by a higher spiral valve count (13 to 17 c.f. 10 to 11 in A. herklotsi), a shorter snout (pre-oral length always 12.3% TL), and fewer tooth rows (36 to 44 and 31 to 41 rows upper and lower jaws c.f. 49 to 57 and 49 to 58 rows). A longicephalus is unique amongst the Apristurus species in having a duodenum almost as long as the valvular intestine. Both species have a continuous supraorbital sensory canal, and similar numbers of monospondylous vertebrae (Nakaya 1988a, 1988b, 1991, Nakaya and Sato 1999).
|Red List Category & Criteria:||Data Deficient ver 3.1|
|Assessor(s):||Duffy, C. & Huveneers, C.|
|Reviewer(s):||Kyne, P.M., Cavanagh, R.D. & Fowler, S.L. (Shark Red List Authority)|
Apristurus longicephalus is recorded over the continental slope at depths of 500 to 1,140 m with a scattered range around Japan, the Seychelles and Northern Australia. Taken as bycatch in deepwater trawl fisheries but at present there is insufficient information available to assess this species beyond Data Deficient.
|Range Description:||The species occurs off southern Japan (Tosa Bay, Shikoku Island; Okinawa Trough, East China Sea); Seychelles, southwest Indian Ocean; Australia (North West Cape and Ashmore Reef, Western Australia; and off Townsville, North Queensland).|
Native:Australia (Queensland, Western Australia); Japan (Shikoku); Seychelles
|FAO Marine Fishing Areas:||
Indian Ocean – eastern; Indian Ocean – western; Pacific – northwest; Pacific – western central
|Range Map:||Click here to open the map viewer and explore range.|
|Current Population Trend:||Unknown|
|Habitat and Ecology:||
A. longicephalus occurs over the continental slope at 500 to 1,140 m depth. Maturity information is only available for a single 39 cm TL female, which had a small undeveloped ovary (Nakaya 1988a). Males mature at 42 cm TL and reach at least 50.1 cm TL (Nakaya 1988). Male size at maturity is smaller than the other Japanese species (A. herklotsi, A. macrorhynchus, A. platyrhynchus and A. japonicus) suggesting A. longicephalus is a relatively small species (Nakaya 1988a). Diet is unknown.
Apristurus species are relatively small, sluggish sharks that live on or near the bottom. Diet includes crustaceans (penaeid shrimps, euphausids), squids and small fishes. Where known reproduction is oviparous with one egg per oviduct. Egg cases are usually thick-walled and about 5 to 6.8 cm long and 2.5 to 2.9 cm wide. The anterior end of the case has a long weak fibrous thread on each corner. The posterior end usually has two small processes, each with a long coiled tendril. As in shallow water scyliorhinids the coiled tendrils are probably used to attach the egg cases to hard substrates and/or biogenic structures as they are laid.
|Major Threat(s):||Deepwater trawl fisheries. Other species of deepwater Chondrichthyans are known to be captured as bycatch in deepwater fisheries. As these fisheries expand globally, consideration needs to be given to the fact that this species too may be captured incidentally in deepwater fisheries.|
|Conservation Actions:||No conservation measures are currently in place for this species.|
|Citation:||Duffy, C. & Huveneers, C. 2004. Apristurus longicephalus. The IUCN Red List of Threatened Species 2004: e.T44217A10873363. http://dx.doi.org/10.2305/IUCN.UK.2004.RLTS.T44217A10873363.en . Downloaded on 04 October 2015.|
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