Small, but beautiful

Most people are unaware our unique native freshwater fishes. They are mostly small and like to remain inconspicuous to protect themselves from predators. You are much more likely to see an introduced fish, such as gambusia or goldfish in your local stream, than to see a native fish. But that doesn’t mean that the natives are not there. You just have to look a bit harder.

Native Fish

There are 11 species of native freshwater fish in the south-west of Western Australia, and nine of these are found nowhere else in the world (the other two species are also found in eastern Australia). Around Perth, the species we are most likely to see are freshwater cobbler (Tandanus bostocki), western minnow (Galaxias occidentalis), western pygmy perch (Nannoperca vittata) and nightfish (Bostockia porosa).


Introduced Fish

Feral Fishes

In Western Australia feral fishes are found mainly in waterways in the vicinity of major urban areas. These introduced freshwater fishes include Goldfish (Carassius auratus); Koi Carp (Cyprinus carpio); Rainbow Trout (Oncorhynchus mykiss); Brown Trout (Salmo trutta); Eastern Mosquitofish (Gambusia holbrooki), One-spot Livebearer (Phalloceros caudimaculatus); Guppy (Poecilia reticulata); Swordtail (Xiphophorus helleri); Redfin Perch (Perca fluviatilis); Mozambique Mouthbrooder (Oreochromis mossambicus); and Eastern Australian Silver Perch (Bidyanus bidyanus).

Feral fishes are a threat to unique native freshwater fishes because they can tolerate degraded habitats, are highly adaptable and reproduce readily. Feral fishes are: predators of native freshwater fishes; compete with native fishes for food decrease water quality; and introduce parasitic diseases, such as anchor worm. They are a significant threat to native freshwater fishes in the south-west of Western Australia, where 82% of fishes are unique local species and 55% of species are endangered.

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