Gobiomorphus australis

(Krefft, 1864)

Striped Gudgeon

Species Summary

A medium-sized gudgeon with a stout, dorsally flattened head, bulbous cheeks and a small, oblique, upturned mouth, Gobiomorphus australis carries five to seven dark horizontal stripes over a dark-brown to grey-green body that lightens on the sides. During the breeding season colour intensifies to a rich, dark chocolate-brown with a purple sheen, the anal fin turning orange in males and golden-yellow in females. It reaches up to 17.5 cm, though most individuals seen are under 12 cm.

Distribution & Habitat

Gobiomorphus australis ranges from the Fitzroy River in Queensland to coastal south-eastern Victoria, east of Wilsons Promontory. A habitat generalist, it is found from muddy waterholes to fast, rocky streams, most abundant at low altitude near the coast, and shows a preference for the freshwater–saltwater interface in spring, moving further into fresh water over summer. It tolerates a wide range of water temperature (9–28 °C), pH (6.5–8.9) and salinity (0–17.9 ppt). Adults live in fresh water, but larvae and small juveniles occur in brackish water, suggesting young fish drift downstream to estuaries before later migrating back upstream — a life-history stage that remains poorly understood. Breeding is believed to occur in late summer or early autumn.

An Urban Refuge

A healthy population of Gobiomorphus australis (alongside the related Cox’s Gudgeon) persists in a small pool — no more than 5×3 m at its largest — in Cooper Park, Bellevue Hill, in the middle of suburban Sydney, fed by a filtered sandstone aquifer that keeps the creek notably cleaner than most urban Sydney waterways. The fish there are unusually unafraid of people, only startled once a net actually approaches, and share the pool with Longfin Eels over a metre long that must travel more than a kilometre through a subterranean storm drain from Sydney Harbour to reach it — a small, resilient pocket of native fish biodiversity worth protecting from the spreading tide of introduced Eastern Mosquitofish found lower in the same catchment.

Compiled for Home of the Rainbowfish from ANGFA sources: Anonymous, “Gobiomorphus australis (Krefft 1864) Striped Gudgeon”, In-Stream 19, 2010, p. 16; W. Woodhouse, “An urban oasis in south-eastern Sydney – the gudgeons of Cooper Park”, Fishes of Sahul 34, 2020, pp. 1531–1535.