See text Neochanna is a genus of galaxiid fishes, commonly known as mudfish, which are native to New Zealand and south-eastern Australia.

[3] Under experimental drought conditions, N. cleaveri created vertical shafts in the mud substrate, which allowed the fish to remain submersed as the free water evaporated.

[3] Mudfish species are geographically widely separate, due to a combination of oceanic dispersal, sea-level change, volcanism and glaciation.

[2]: 305 Of the New Zealand species, the Canterbury and Chatham mudfishes are the least departed from the ancestral form, retaining small pelvic fins and a more Galaxias-like shape.

This is possibly due to the effects of volcanism causing local extinction, and the species was unable to recolonise affected catchments as it has lost the highly mobile amphidromous life cycle.

[2]: 308  The absence of brown mudfish (or other Neochanna species) from the southern half of the west coast of the South Island is likely due to glaciation in the late Pleistocene, although there has been some range expansion into the glacier-affected areas.

[3] It is suggested that the common ancestor of both species was found throughout the northern North Island, but it was divided into two populations by high sea levels during the Pliocene.