Australian Longnose Skate, Dentiraja confusus Last 2008


Other Names: Longnose Skate, Long-nosed Skate

Dipturus confusus. Source: CSIRO National Fish Collection. License: CC by Attribution

Summary:
A brownish or yellowish-brown skate, with a pattern of paler and darker spots and reticulations, and a mostly whitish underside with greyish areas over most of the head, on the belly and near the cloaca, and black-edged sensory pores.
This species was previously referred to as Dipturus confusus.

Cite this page as:
Bray, D.J. 2021, Dentiraja confusus in Fishes of Australia, accessed 31 Jul 2021, https://fishesofaustralia.net.au/home/species/2650

Australian Longnose Skate, Dentiraja confusus Last 2008

More Info


Distribution

Endemic to southeastern Australia, from Sydney, New South Wales, to Portland, Victoria, including around Tasmania. Inhabits soft bottom sediment areas on the continental shelf and slope.

Features

Disc weakly quadrangular; ventral edge of disc at eye level granular; snout moderately elongate (orbital diameter 24–31% preorbital length); 6–14 prominent orbital thorns; 0–7 (usually more than one) nuchal thorns; tail short (65–75% precloacal length in adults), very depressed, broad; lateral skin folds almost to apex; claspers rather broad, not bulbous distally.

Colour

Usually brownish or yellowish dorsally with paler spots, blotches and reticulations; mostly whitish ventrally with grey areas and black-edged pores.

Biology

Males mature at ~47 cm TL, aged about 6 years; females mature at ~53 cm TL, aged about 7 years; maximum age 12 years; resulting generation length is 9.5 years. The species is oviparous with young hatching out at ~10 cm TL after 96-180 days.

Fisheries

Taken as bycatch in the Southern and Eastern Scalefish and Shark Fishery (SESSF). This species is caught in the greatest abundances by otter trawl in the South East Trawl Fishery sector (SETF) but are also caught in lower abundances by Danish seine in the SETF, and deepwater longlines in the Gillnet, Hook and Trap Fishery sector (GHATF). More than 90% of catches occur in water <199 m deep.The majority of the catch is retained for  human consumption.

Conservation

Populations have shown evidence of significant decline since the 1970s based on fisheries observer data.

Similar Species

The rough patch of denticles along the ventral edge of the snout distinguishes the Longnose Skate from the closely related and sympatric Whitespotted Skate, Dipturus cerva, which lacks denticles along the edge of the snout.

Etymology

The specific name confusus is from the Latin confusio (= confounding, confusion, disorder) in reference to the past confusion with other Australasian skates, Dipturus cerva and Zearaja nasuta (a New Zealand endemic).

Species Citation

Dipturus confusus Last 2008, in Last, White, Pogonoski & Gledhill (eds). CSIRO Marine and Atmospheric Research Paper No. 021: 61. Type locality: east of Lakes Entrance, Victoria, Australia, 37°52'S, 148°11'E, depth 27-28 m.

Author

Bray, D.J. 2021

Resources

Atlas of Living Australia

Australian Longnose Skate, Dentiraja confusus Last 2008

References


Graham, K.J., Andrew, N.L. and Hodgson, K.E. 2001. Changes in relative abundance of sharks and rays on Australian South East Fishery trawl grounds after twenty years of fishing. Marine and Freshwater Research 52: 549–561.

Heupel, M.R., Kyne, P.M., White, W.T. & Simpfendorfer, C.A. 2018. Shark Action Plan Policy Report. Report to the National Environmental Science Program, Marine Biodiversity Hub. Australian Institute of Marine Science, 62 pp.

Kyne, P.M. & Sherman, C.S. 2016. Dipturus confusus. The IUCN Red List of Threatened Species 2016: e.T70688138A70688281. https://dx.doi.org/10.2305/IUCN.UK.2016-1.RLTS.T70688138A70688281.en. Downloaded on 10 May 2021.

Last, P.R. 2008. New short-snout members of the skate genus Dipturus (Rajoidei: Rajidae) from Australian seas. pp. 9-52 in Last, P.R., White, W.T., Pogonoski, J.J. & Gledhill, D.C. (eds). Description of new Australian skates (Batoidea: Rajoidei). CSIRO Marine and Atmospheric Research Paper No. 021: 1-181 

Last, P.R., Séret, B., Stehmann, M.F.W. & Weigmann, S. 2016. 19. Skates. Family Rajidae. pp. 204-363 in Last, P.R., White, W.T., Carvalho, M.R. de, Séret, B., Stehmann, M.F.W. & Naylor, G.J.P. (eds.) Rays of the World. Clayton South, Victoria : CSIRO Publishing 790 pp. 

Last, P.R. & Stevens, J.D. 1994. Sharks and Rays of Australia. Canberra : CSIRO Australia 513 pp. 84 pls. (as Raja sp. A)

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

Last, P.R., Weigmann, S. & Yang, L. 2016. Changes to the nomenclature of the skates (Chondrichthyes: Rajiformes). Rays of the World: Supplementary Information. CSIRO Special Publication. pp. 11-34 

Last, P.R. & White, W.T. 2008. Family Rajidae. 108-124 pp. in Gomon, M.F., Bray, D.J. & Kuiter, R.H. (eds). Fishes of Australia's Southern Coast. Sydney : Reed New Holland 928 pp. (as Dipturus sp. 1)

May, J.L. & Maxwell, J.G.H. 1986. Field Guide to Trawl Fish from Temperate Waters of Australia. Hobart : CSIRO Division of Marine Research 492 pp. (as Raja sp. 1)

Treloar, M.A. 2008. Aspects of the life history of skates from southeastern Australia. PhD thesis, Deakin University, Victoria, Australia.

Whitley, G.P. 1940. The Fishes of Australia. Part 1. The sharks, rays, devil-fish, and other primitive fishes of Australia and New Zealand. Sydney : Roy. Zool. Soc. N.S.W. 280 pp. 303 figs. (as Raja nasuta)

Quick Facts


CAAB Code:37031005

Conservation:IUCN Critically Endangered

Depth:18-600 m

Habitat:Soft sediment areas

Max Size:70 cm TL

Species Image Gallery

Species Maps

CAAB distribution map