Animal Species:Flathead Gudgeon, Philypnodon grandiceps (Krefft, 1864)
The Flathead Gudgeon is a common freshwater fish of eastern Australia. The standard name refers to its broad, flattened head.
Standard Common Name
Big-headed Gudgeon, Bull Head, Bull-headed Gudgeon, Collundera, Yarra Gudgeon
The Flathead Gudgeon is an elongate species with two short-based dorsal fins. It has a broad, flattened head with rows of small papillae. The mouth is large, extending back to below the middle to rear half of the eye in males and under the front of the eye in females.
Colouration of the species varies from black, brown, grey or reddish to greenish-brown overall. There are faint dark blotches on the back behind the head and below the dorsal fins. The sides of the body have irregular faint brown markings and thin bands on the lower sides and belly. The body is yellowish ventrally. There is a dark spot on the caudal fin base and several dark lines radiating from the eyes. The caudal and dorsal fins have alternating grey and orange bands.
The species grows to about 12 cm in length but is more commonly seen up to 8 cm.
The Flathead Gudgeon looks similar to the smaller Dwarf Flathead Gudgeon. It can be distinguished by its maximum size of 110 mm (50 mm in the Dwarf Flathead Gudgeon), wide gill openings (gill openings narrower), thin bands on the lower sides of body and belly (lines absent), pectoral rays 18-19 (15-16) and gill rakers on first arch 14-20 (11-12).
The species is endemic to Australia, occurring from coastal rivers of the Mackay region, Queensland to the Murray River, South Australia. It is also known from inland waters of the Murray-Darling drainage from Lachlan River, New South Wales to the Murray River, South Australia. It also occurs in northern Tasmania.
The map below shows the Australian distribution of the species based on public sightings and specimens in Australian Museums. Click on the map for detailed information. Source: Atlas of Living Australia.
Distribution by collection data
It is a benthic species that is primarily found on muddy bottoms, often amongst vegetation. The species occurs in freshwaters, but is also recorded from estuarine and protected areas in coastal bays.
Mating and reproduction
Breeding occurs mainly in spring and summer. At this time the colouration of males darken and become more vibrant.
- Allen, G.R. 1989. Freshwater Fishes of Australia. T.F.H. Publications. Pp. 240.
- Allen, G.R., Midgley, S.H. & M. Allen. 2002. Field Guide to the Freshwater Fishes of Australia. Western Australian Museum. Pp. 394.
- Larson, H.K & D.F. Hoese in McDowall, R.M. 1996. Freshwater Fishes of South-Eastern Australia. Reed Books. Pp. 247.
- Merrick, J.R. & G.E. Schmida. 1984. Australian Freshwater Fishes. Biology and Management. John R. Merrick. Pp. 409.
Mark McGrouther , Senior Fellow
Tags Fishes, Ichthyology, Flathead Gudgeon, Philypnodon grandiceps, Eleotridae, black, brown, grey, reddish, greenish-brown, long, 10 cm - 30 cm, complex pattern, soft substrate (mud), freshwater, flattened head, big mouth, blotches,