Smoothbelly Catshark, Apristurus longicephalus Nakaya 1975

Other Names: Longhead Catshark

Smoothbelly Catshark, Apristurus longicephalus. Source: Australian National Fish Collection, CSIRO. License: CC by Attribution-NonCommercial-ShareAlike

Summary:

A uniformly dark greyish-brown to blackish catshark with black naked patches of skin on a large antero-ventral area, and a black oral cavity. The species has an extremely long, narrow snout, widely separated nostrils, long anal and caudal fins, a short abdomen, and very sparse teeth.

Cite this page as:

Bray, D.J. 2023, Apristurus longicephalus in Fishes of Australia, accessed 10 Dec 2023, https://fishesofaustralia.net.au/home/species/1672

Smoothbelly Catshark, Apristurus longicephalus Nakaya 1975

More Info

Distribution	Southwest of Shark Bay, Western Australia to Ashmore Reef in the Timor Sea, and off Townsville, Queensland. Elsewhere the species has a patchy distribution in the tropical, Indo-west Pacific.
Features	Vertebrae 30-33 (monospondylous) Body very narrow, elongate; head long, about 25% total length (TL); snout flattened, bell-shaped, narrowing considerably in front of the nostrils, about 12% TL; nostrils oblique, divided into large, oval incurrent and excurrent openings by triangular flaps of skin on their anterior rims; eyes small, horizontally oval eye, somewhat upward-facing, with rudimentary nictitating membranes. Mouth forming a short, wide arch, with well-developed furrows around the corners. Upper jaw teeth in 36-44 rows, lower jaw teeth in more than 45 rows; teeth well-spaced, with 3-5 cusps, central cusp much longer than the others. Gill slits short, fourth and fifth pairs over pectoral-fin base. First dorsal fin with a rounded apex, positioned above rear third of pelvic-fin base; second dorsal fin similar, much larger than first, over rear half of anal-fin base. Pectoral fins moderately large, broad; pelvic fins of medium size, rounded, positioned near pectoral fins. Anal fin elongate, angular, separated from caudal fin only by a deep notch; caudal fin narrow, about one-third TL, with a distinct lower lobe and ventral notch near the tip of upper lobe. Dermal denticles tiny, well-spaced, each with a median ridge and three posterior points, giving the skin a velvety texture. Large patch of naked skin extending from throat and gill region, around pectoral fins, over side and abdomen, to between pelvic-fin and anal-fin bases; denticles also absent near fin margins.
Biology	Males mature at 49 cm total length (TL), females at 51 cm TL. The reproductive mode is oviparous, with females having a single egg capsule per oviduct. This is the first record of a cartilaginous fish with rudimentary hermaphroditism (Iglésias et al. 2005). The holotype was originally thought to be an immature male, however, subsequent research showed it to be functionally a female.
Etymology	The specific name longicephalus is from the Latin longus (= long) and the Greek kephale (= head) in reference to the long head of this species.
Species Citation	Apristurus longicephalus Nakaya 1975, Memoirs of the Faculty of Fisheries, Hokkaido University 23(1): 32, figs 15-16. Type locality: Sea of Japan, Tosa Bay, 33°13'N, 133°44'E, Kochi Prefecture, Japan.
Author	Bray, D.J. 2023
Resources	Atlas of Living Australia Australian Faunal Directory Catalog of Fishes

Smoothbelly Catshark, Apristurus longicephalus Nakaya 1975

References

Compagno, L.J.V. 1984. FAO Species Catalogue. Sharks of the World. An annotated and illustrated catalogue of shark species known to date. Carcharhiniformes. FAO Fisheries Synopsis No. 125. Rome : FAO Vol. 4(2) 251-655 pp.

Compagno, L.J.V., Dando, M. & Fowler, S. 2005. A Field Guide to the Sharks of the World. London : Collins 368 pp.

Compagno, L.J.V. & Niem, V.H. 1998. Families Scyliorhinidae, Proscylliidae. pp. 1279-1292 in Carpenter, K.E. & Niem, V.H. (eds). The Living Marine Resources of the Western Central Pacific. FAO Species Identification Guide for Fisheries Purposes. Rome : FAO Vol. 2 687-1396 pp.

Duffy, C.A.J. & Huveneers, C. 2015. Apristurus longicephalus. The IUCN Red List of Threatened Species 2015: e.T44217A68608927. https://dx.doi.org/10.2305/IUCN.UK.2015-4.RLTS.T44217A68608927.en. Accessed on 17 August 2023.

Iglésias, S.P., Sellos, D.Y. & Nakaya, K. 2005. Discovery of a normal hermaphroditic chondrichthyan species: Apristurus longicephalus. Journal of Fish Biology 66(2): 417-428.

Last, P.R. & Stevens, J.D. 1994. Sharks and Rays of Australia. Canberra : CSIRO Australia 513 pp. 84 pls.

Last, P.R. & Stevens, J.D. 2009. Sharks and Rays of Australia. Collingwood : CSIRO Publishing Australia 2, 550 pp.

Nakaya, K. 1975. Taxonomy, comparative anatomy and phylogeny of Japanese catsharks, Scyliorhinidae. Memoirs of the Faculty of Fisheries, Hokkaido University 23(1): 1-94 figs 1-43. http://hdl.handle.net/2115/21861

Nakaya, K. 1988. Morphology and taxonomy of Apristurus longicephalus (Lamniformes, Scyliorhinidae). Japanese Journal of Ichthyology 34(4): 431–442. https://doi.org/10.1007/BF02905649

Nakaya, K. 1991. A review of the long-snouted species of Apristurus (Chondrichthyes, Scyliorhinidae). Copeia 1991(4): 992-1002. https://doi.org/10.2307/1446094