Estuary Cobbler, Cnidoglanis macrocephalus (Valenciennes 1840)

Other Names: Cobbler, Estuarine Cat-fish, Estuary Catfish, South Australian Catfish

An Estuary Cobbler, Cnidoglanis macrocephalus, at Halifax Park, Port Stephens, New South Wales. Source: Dave Harasti / License: All rights reserved


A large mottled brownish-yellow catfish with stout dorsal and pectoral-fin spines and five pairs barbels surrounding the mouth. Estuary catfish have large venomous dorsal and pectoral-fin spines that are capable of inflicting very painful wounds.

Video of an Estuary Cobbler at Shelly Beach, Sydney

Cite this page as:
Gomon, M.F. & Bray, D.J. 2018, Cnidoglanis macrocephalus in Fishes of Australia, accessed 17 Jun 2024,

Estuary Cobbler, Cnidoglanis macrocephalus (Valenciennes 1840)

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Endemic to temperate coastal waters of southern Australia, from Moreton Bay, Queensland, to the Abrolhos Islands (Western Australia), but absent from most of Victoria and Tasmania; occurs in Eastern Victoria (to about Lakes Entrance) and Duck River, northern Tasmania. 

The Estuary Cobbler inhabits marine and estuarine waters in bays and sandy or muddy inlets near river mouths. Individuals live on sandy and muddy bottoms in clear to turbid waters, often amongst rocks and algae. They also occur amongst wrack (detached seagrass and macroalgae) in the surf zone. 

The species is usually nocturnal, and individuals often shelter in holes and beneath rocky ledges during the day.


Dorsal fin I, 4; Anal fin 95-112; Pectoral fin  I, 9; Pelvic fin  9-12.

Body shallow (11-15% SL), very elongate, thick anteriorly, compressed and tapering to a point posteriorly. Head large (20-23% SL), depressed anteriorly;  eyes small (13-16% HL), covered by skin, located dorsolaterally on head;  mouth small (upper jaw length 26-28% HL), inferior, overlapped by large fleshy lips, underside of lips papillose, mouth surrounded by four pairs of long fleshy barbels, fifth pair on snout; small patch of short canines at front of each jaw;  forward end of opercular membrane attached to underside of head below and behind eye. Scales absent; lateral line represented by pores, straight except for curve above pectoral fins.  

Dorsal fin with short base, arising above pectoral fin base, spine serrate, enveloped in skin; anal and caudal fins continous, caudal continuing forward on back to just behind dorsal fin, resembling a second dorsal fin; caudal-fin rays slightly longer than anal-fin rays, anal fin originating almost as far forward as dorsal side of caudal fin. Anal fin preceded by large fleshy dentritic organ. Pectoral and ventral fins small, paddle-like; pectoral fin arising midlaterally behind head, spine serrate; pelvic fins arising below pectoral-fin tips.


To a total length of about 91 cm SL.


Variously mottled dark brown to grey, often with speckles of cream or yellow, underside of head and belly creamy.


Omnivore - feeds mostly at night on fishes and benthic invertebrates including crustaceans, molluscs and polychaete worms. Individuals also consume algae and detritus.


The sexes are separate, fertilisation is external, and females lay large demersal eggs during spring and summer. Adult males guard the newly hatched larvae between their pelvic fins.


A major component of both commercial and recreational fisheries in New South Wales and Western Australia.


IUCN Red List Status: Data Deficient


The dorsal and pectoral-fin spines are serrated and have a venom gland at the base. The venom is injected into punctured skin via a groove in the spine, causing an extremely painful wound.


The species is named macrocephalus for its large head: macro- (large) and cephalus (head).

Species Citation

Plotosus macrocephalus Valenciennes, 1840 in Cuvier & Valenciennes, Hist. Nat. Poiss.15: 428, pl. 449. Type Locality: Timor Island, southern Malay Archipelago (probably in error for Tasmania, Australia).


Gomon, M.F. & Bray, D.J. 2018


Australian Faunal Directory

Estuary Cobbler, Cnidoglanis macrocephalus (Valenciennes 1840)


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Castelnau, F.L. de 1873. Contribution to the ichthyology of Australia. 8. Fishes of Western Australia. Proceedings of the Zoological and Acclimatisation Society of Victoria 2: 123-149 (p. 140, as Cnidoglanis bostocki)

Castelnau, F.L. de 1875. Researches on the fishes of Australia. Intercolonial Exhibition Essays. 2. pp. 1–52 in, Philadelphia Centennial Exhibition of 1876 : Official Record. Melbourne. ( p. 45, as Neoplotosus waterhousii).

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

Crawley KR, GA Hyndes & SG Ayvazian. 2006. Influence of different volumes and types of detached macrophytes on fish community structure in surf zones of sandy beaches. Mar Ecol Prog Ser 307: 233–246.

Edgar, G.J. 1997. Australian Marine Life: the plants and animals of temperate waters. Reed Books. 544 pp.

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Gomon, M.F. 1994. Family Plotosidae, 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.

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

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Kner, R. 1867. Fische, Dritte Abteilung. Reise der österreichischen Fregatte Novara um die Erde in den Jahren 1857–1858–1859, unter den Befehlen des Commodore B. von Wüllestorf-Urbair. Zoologischer Theil 1. Wien : Kurl Gerold's & Sohn Vol. 5 273-433 pp. 12-16 pls. (p. 300, pl. 12(1), as Choeroplotosus decemfilis)

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Laurenson, L.J.B., Potter, I.C., Lenanton, R. & Hall, N.G. 1993. The significance of length at sexual maturity, mesh size and closed fishing waters to the commercial fishery for the catfish Cnidoglanis macrocephalus in Australian estuaries. Journal of Applied Ichthyology 9: 210–221.

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Quick Facts

CAAB Code:37192001

Conservation:IUCN Data Deficient

Danger:Venomous spines

Depth:0-30 m

Fishing:Commercial, recreational fish

Max Size:91 cm SL


Species Maps

CAAB distribution map