Eldon's galaxias

Appearance

Its snout shape is variable depending on whether it lives on a stream or wetland habitat. It is orange-brown to olive-brown with very variable dark brown markings that can be speckles, spots, or irregular bands, and its skin is heavily dusted with gold. Sometimes it has a small black patch behind the gill cover (operculum).

Eldon's galaxias is an elongated, deep-bodied Galaxias, usually 80 mm in length (although very large individuals can reach 155 mm).

Since the species was described in 1997 several small populations have been driven extinct from conversion of land to forestry or farming.

Range and habitat

This species lives only in eastern waterways of Otago, in wetlands and small streams that flow into the Taieri, Tokomairiro and Waipori rivers and below Lake Mahinerangi. It tends to be found upstream of waterfalls that block the movement of introduced salmonid fishes such as brown trout, rainbow trout, and brook char. Its original distribution was likely much larger, but trout species have eradicated it in all but the headwaters that make up its current home range.

Pins are Wikidata “endemic to” fields. Orange dots, when present, are GBIF occurrence tiles — survey bias included.

Breeding

Spawning occurs at the stream edge in riffles, and eggs are laid directly into the stony stream bottom. The larvae are large and are able to swim effectively. They do not disperse far from where they were spawned.

In crisis

Eldon's galaxias is an endangered galaxiid fish endemic to New Zealand. One of several fishes in the genus Galaxias found in Central Otago, it has a very small home range and is at risk of being driven to extinction by trout introduced for recreational fishing. This species is rated Nationally Endangered by the Department of Conservation and critically endangered by the IUCN, due to its small number of streams it occupies (an area of just 0.69 km2) and the threats of invasive species.

Because G. Eldoni lays very few eggs and has large, poorly dispersing fry, it is vulnerable to predation by introduced trout. Currently there are protected areas for this species in the Lammerlaw Range, but they are vulnerable to being invaded by trout, or trout being deliberately introduced.

Eldon's galaxias is Critically Endangered on this catalog because that is the IUCN category stored on Wikidata. Confirm the official criteria and any later count on iucnredlist.org.

Sources

Written for this catalog from the English Wikipedia article on Eldon's galaxias, Wikidata item Q5254084. Family and order context is original field-guide writing about the group, not a copied assessment of this one species. Wikipedia text is CC BY-SA. Not an IUCN assessment. Counts, when quoted, can change — confirm them on the recovery programme and on iucnredlist.org.