Mudfish/waikaka/hauhau/kowaro are regarded as a taonga (treasured) species to iwi. They look like cigar-shaped, stocky eels with slippery skin covered with dark greenish-brown speckling. Most mudfish live in weedy drains, wetlands and pools in swamp forest, although the Chatham Island mudfish lives in lakes. Mudfish survive when the water dries up by hiding away underneath logs or debris and emerge when rain falls. They grow to about 11cm.

There are five species of mudfish, all of which are threatened:

Brown mudfish. Photo copyright: Stephen Moore. DOC USE ONLY.
Brown mudfish

  • Northland mudfish - found around Kerikeri and Ngawha
  • Black mudfish - found in Northland and Waikato
  • Brown mudfish - mainly found in southern North Island and the West Coast of the South Island
  • Canterbury mudfish - found in Canterbury as far south as the Waitaki catchment
  • Chatham Island mudfish - a recently discovered mudfish species, found in three lakes and a stream on Chatham Island.

Once widespread in swamps and wetlands, mudfish are now found in only a few sites – mostly on private land. DOC is working with landowners to protect these key remaining habitats.

A fish out of water?

Mudfish can do something most other fish can't – they can survive without water for about two months! All they need is vegetative cover to keep themselves moist. Then, when summer is over and water returns to the wetland, they can eat, swim and breed. This adaptation means that mudfish can live in places other fish can't.

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