The torrentfish (Cheimarrichthys fosteri), or panoko (Māori), is an amphidromous freshwater ray-finned fish that is endemic to New Zealand.

[3] Torrentfish are stocky, with a flattened underside, arched back and a broad, downward-tapering head with eyes set high.

[3] The lower jaw is very undercut and is surrounded by a fleshy upper lip – an adaptation for picking invertebrates off the surface of stones.

[5] They favour rivers with highly unstable substrates, as the regular movement of the gravels maintains open gaps around and underneath the stones where the torrentfish can take refuge from fast water.

[7] Torrentfish are amphidromous: the fry go to sea after hatching, and return as juveniles to fresh water where they grow to adulthood.

[3][7] Females migrate downstream over summer and autumn when ready to lay eggs, and return upstream once spent.

[9] Because they have to spend time at sea, torrentfish are unable to form landlocked populations like some other New Zealand native fishes.