Nightfish – Bostockia porosa

Nightfish are related to Western Pygmy perch and have a similar shape, but they are larger (up to 170 mm), with conspicuous pores on the head and a large mouth.

In colour, they are mottled olive brown to dark brown, with a paler belly.

Nightfish prefer still or slow-moving waters. Adults are solitary and nocturnal, hiding amongst rocks and woody debris during the day. They are best seen using a torch at night. Rocky pools are ideal places to search. They are ambush predators, waiting on the bottom to snap up insects, crustaceans, snails and small fishes that venture too close.

Although rarely seen, nightfish are reasonably common and widespread. However, they do seem to be declining in catchments that are salinized or where clearing has reduced the instream woody debris that they use for shelter.