New Zealand status: Endemic
Conservation status: At Risk – Naturally Uncommon
International conservation status: Vulnerable (IUCN)
Found in: Throughout New Zealand's North and South Islands.
Threats: Habitat disturbance, gravel mining and invasive woody tree species.
Appearance and size
Torrentfish (Cheimarrichthys fosteri) grow up to 200 mm in length and have distinct broad stripes along the sides of their bodies. Juveniles look the same as adult fish, just smaller. They have flat heads and large pectoral fins that help to anchor the fish on a riverbed and counter strong currents. Their raised eyes and low mouths are likely to be adaptations for feeding in river habitats.
Torrentfish are the only freshwater member of the Cheimarrichthyidae family in New Zealand, and are closely related to blue cod.
Where they live
Torrentfish are common in open rivers, living in fast-flowing rapids of stony rivers and streams. They are unable to climb steep sections of river or waterfalls, and only reach inland areas where the rivers are gently sloping. Female fish tend to be found the furthest inland. Males stay nearer the coast.
Lifecycle
Torrentfish move between freshwater and the ocean during their lifecycle in the same way as the migratory galaxiids.
Inanga lifecycle
Image: DOC