Bluefin Leatherjacket, Thamnaconus degeni (Regan 1903)

Other Names: Blue-finned Leatherjacket, Bluefinned Leatherjacket, Degens Leatherjacket, Degen's Leatherjacket

A male Bluefin Leatherjacket, Thamnaconus degeni, caught off Lorne, Victoria, depth ~30 m. Source: Keith Miller / Lorne Aquatic & Angling Club. License: All rights reserved

Males are pale brownish-grey to pale greenish-grey, with scattered bright blue spots, a bright blue line along the dorsal and anal fin bases, bluish-green fin rays and bright blue tail fin membranes. Females and juveniles are pale brown, often with small brown spots above.

Cite this page as:
Bray, D.J. 2018, Thamnaconus degeni in Fishes of Australia, accessed 29 Mar 2023,

Bluefin Leatherjacket, Thamnaconus degeni (Regan 1903)

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Endemic to southern Australia from Merimbula, southern New South Wales, to the Great Australian Bight, Western Australia, and around Tasmania. Although Bluefin Leatherjackets usually inhabit offshore reefs, they also enter coastal bays and inlets.


Dorsal fin II + 33-38; Anal fin 32-37; Caudal fin 12; Pectoral fin 12-14; Vertebrae 19.
Body very elongate, oblong in large males, of moderate depth in females and juveniles; ventral flap small; central pair of teeth in jaws pointed; skin velvety to touch; no spines or bristles on tail base; first dorsal spine slender with very small to minute barbs.


Frequently taken in commercial trawls.


The species is named degeni after Mr Degen, who provided C. Tate Regan with a specimen from the Melbourne Market, along with an illustration showing the actual colours of the specimen when it was fresh.

Species Citation

Pseudomonacanthus degeni Regan, 1903, Proc. Zool. Soc. Lond. 1902(2,2): 299. Type locality: Melbourne market.


Bray, D.J. 2018


Australian Faunal Directory

Bluefin Leatherjacket, Thamnaconus degeni (Regan 1903)


Edgar, G.J. 2008. Australian Marine Life: the plants and animals of temperate waters. Sydney : Reed New Holland 2nd edn, 624 pp.

Grant, E.M. 1991. Fishes of Australia. Brisbane : EM Grant Pty Ltd 480 pp.

Hill, N.A., Barrett, N., Lawrence, E., Hulls, J., Dambacher, J.M., Nichol, S., et al. 2014. Quantifying Fish Assemblages in Large, Offshore Marine Protected Areas: An Australian Case Study. PLoS ONE 9(10): e110831.

Hutchins, J.B. 1977. Descriptions of three new genera and eight new species of monacanthid fishes from Australia. Records of the Western Australian Museum 5(1): 3-58 figs 1-13

Hutchins, J.B. 1994. Family Monacanthidae. pp. 866-891 figs 767-787 in Gomon, M.F., Glover, C.J.M. & Kuiter, R.H. (eds). The Fishes of Australia's South Coast. Adelaide : State Printer 992 pp. 810 figs.

Hutchins, J.B. 2008. Family Monacanthidae. pp. 822-841 in Gomon, M.F., Bray, D.J. & Kuiter, R.H. (eds). Fishes of Australia's Southern Coast. Sydney : Reed New Holland 928 pp.

Hutchins, J.B. & Swainston, R. 1986. Sea Fishes of Southern Australia. Complete field guide for anglers and divers. Perth : Swainston Publishing 180 pp.

Kuiter, R.H. 1993. Coastal Fishes of South-eastern Australia. Bathurst : Crawford House Press 437 pp.

Last, P.R., Scott, E.O.G. & Talbot, F.H. 1983. Fishes of Tasmania. Hobart : Tasmanian Fisheries Development Authority 563 pp. figs.

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.

Regan, C.T. 1903. On the classification of the fishes of the suborder Plectognathi, with notes and descriptions of new species from specimens in the British Museum collection. Proceedings of the Zoological Society of London 1902(2,2): 284-303 figs 56-59 pls 24-25 PDF Open access

Swainston, R. 2011. Swainston's Fishes of Australia: The complete illustrated guide. Camberwell, Victoria : Penguin Australia 836 pp.

Whitley, G.P. 1939. Studies in Ichthyology No. 12. Records of the Australian Museum 20(4): 264-277 figs 1-3 DOI:10.3853/j.0067-1975.20.1939.576 Open access (as Nelusetta degeni)

Yearsley, G.K., Last, P.R. & Ward, R.D. (eds) 1999. Australian Seafood Handbook. Hobart : CSIRO Marine Research 460 pp.

Quick Facts

CAAB Code:37465037

Depth:4-80m (mostly 30-70m)

Habitat:Reef associated

Max Size:30 cm TL


Species Image Gallery

Species Maps

CAAB distribution map