Mosaic Leatherjacket, Eubalichthys mosaicus (Ramsay & Ogilby 1886)

Other Names: Deep Bodied Leatherjacket, Deep-bodied Leatherjacket, Dinnerplate Leatherjacket, Oval Leatherjacket

A Mosaic Leatherjacket, Eubalichthys mosaicus, at Bare Island, Botany Bay, New South Wales. Source: John Turnbull / Flickr. License: CC by Attribution-NonCommercial-ShareAlike

Adults are bluish to brownish-grey with yellow to yellowish-brown oval blotches, some forming lines along sides, or with blue stripes along sides, and greenish fins. Juveniles are pale grey to yellow or orange with blue lines/stripes and brownish oval blotches along sides, and often a white blotch near the pectoral fin.
A Mosaic Leatherjacket at 'The Steps', Kurnell, Botany Bay, New South Wales - depth 12 m.

Cite this page as:
Dianne J. Bray, Eubalichthys mosaicus in Fishes of Australia, accessed 19 Apr 2024,

Mosaic Leatherjacket, Eubalichthys mosaicus (Ramsay & Ogilby 1886)

More Info


Endemic to the southern half of Australia from Noosa, Queensland, to Dongara, Western Australia. Adults usually inhabit deep offshore reefs to 150 metres, while juveniles are found in estuaries and on sheltered coastal reefs. Juveniles are often seen around jetty piles and under jellyfishes.


Dorsal fin II, 33-37; Anal fin 32-36; Caudal fin 12; Pectoral fin 12-14.

Body very compressed, roughly circular in females and juveniles to oval in males, with a small ventral flap; caudal peduncle shallow. Head large, broadly pointed; eyes small; mouth very small; teeth large, central pair in both jaws pointed; gill openings in form of small slit mostly above each pectoral fin base. 

Skin smooth to touch; no spines or bristles on caudal peduncle; lateral line difficult to detect. 

Two dorsal fins, first dorsal above eyes, consisting of prominent spine with small barbs decreasing in size as body length increases, approaching obsolescence, spine partly received into shallow groove when depressed, second dorsal widely separated from first, of moderate length, elevated anteriorly in males, outer margin slightly convex and not elevated anteriorly in females; anal fin similar to and opposing second dorsal; caudal fin rounded. Pectoral fins moderately small, rounded. Pelvic fins rudimentary, rudiment small to minute, located about one eye diameter in advance of rear end of pelvis.


Adults bluish to brownish grey with yellow to yellowish brown oval blotches on sides, some of which may join together to form longitudinal lines and brownish oval blotches, or yellow with blue longitudinal stripes along sides; all fin rays greenish. Juveniles pale grey with blue longitudinal lines and brownish oval blotches, or yellow with blue longitudinal stripes along sides; occasionally dark brown blotches on body and white blotch near each pectoral fin.

Species Citation

Monacanthus mosaicus Ramsay & Ogilby, 1886, Proc. Linn. Soc. N.S.W. (2)1(1): 4. Type locality: Port Jackson, New South Wales.


Dianne J. Bray


Australian Faunal Directory

Mosaic Leatherjacket, Eubalichthys mosaicus (Ramsay & Ogilby 1886)


Coleman, N. 1980. Australian Sea Fishes South of 30ºS. Lane Cove, NSW : Doubleday Australia Pty Ltd 309 pp.

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

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. A survey of the nearshore reef fish fauna of Western Australia's west and south coasts — The Leeuwin Province. Records of the Western Australian Museum, Supplement 46: 1-66 figs 1-6

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. 2001. Biodiversity of shallow reef fish assemblages in Western Australia using a rapid censusing technique. Records of the Western Australian Museum 20: 247-270'

Hutchins, J.B. 2001. Monacanthidae. pp. 3929-3947 in Carpenter, K.E. & Niem, T.H. (eds). The Living Marine Resources of the Western Central Pacific. FAO Species Identification Guide for Fisheries Purposes. Rome : FAO Vol. 6 pp. 3381-4218.

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. & Thompson, M. 1983. The Marine and Estuarine Fishes of South-western Australia. Perth : Western Australian Museum 103 pp. 345 figs.

Johnson, J.W. 2010. Fishes of the Moreton Bay Marine Park and adjacent continental shelf waters, Queensland, Australia. pp. 299-353 in Davie, P.J.F. & Phillips, J.A. Proceedings of the Thirteenth International Marine Biological Workshop, The Marine Fauna and Flora of Moreton Bay. Memoirs of the Queensland Museum 54(3)

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.

Ramsay, E.P. & Ogilby, J.D. 1886. Descriptions of some new Australian fishes. Proceedings of the Linnean Society of New South Wales 2 1(1): 4-7 [dated 1887]

Scott, T.D. 1962. The Marine and Freshwater Fishes of South Australia. Adelaide : Government Printer 338 pp. figs.

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

Thomson, J.M. 1978. A Field Guide to the Common Sea & Estuary Fishes of Non-tropical Australia. Sydney : Collins 144 pp.

Whitley, G.P. 1930. Leatherjacket genera. The Australian Zoologist 6(2): 179

Quick Facts

CAAB Code:37465003

Behaviour:Juveniles associate with jellyfish

Depth:6-150 m

Habitat:Reef associated

Max Size:60 cm TL


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