Galaxiid

Galaxiidae
A mountain galaxias.
Scientific classification
Kingdom: Animalia Phylum: Chordata Subphylum: Vertebrata Class: Actinopterygii Order: Osmeriformes Family: Galaxiidae
Genera
Aplochiton Brachygalaxias Galaxias Galaxiella Lovettia Neochanna Paragalaxias

The Galaxiids are a family of mostly small freshwater fish. Representatives occur throughout the southern hemisphere, including South Africa, South America, New Zealand, Australia, Lord Howe Island, New Caledonia and the Falkland Islands. One species of galaxiid, Galaxias maculatus, is probably the most widely naturally distributed freshwater fish in the world. They are cool water species, found in temperate latitudes, with only one species known from sub-tropical habitat (McDowall, 2006). Many specialise in living in cold, high altitude upland rivers, streams and lakes.

Some Galaxiids live in freshwater all their lives but many include a partially marine life cycle. In these cases, larvae are hatched in a river but are washed downstream to the ocean, later returning to rivers as juveniles to complete their development to full adulthood. This pattern differs from that of salmon, which only return to freshwater to breed, and is described as amphidromous.^[1]

Freshwater galaxiid species are gravely threatened by exotic salmonid species, particularly exotic trout species, which predate upon galaxiids and compete with them for food. Exotic salmonids have been recklessly introduced to many different landmasses (e.g. Australia, New Zealand), with no thought as to impacts on native fish, or attempts to preserve salmonid-free habitats for them. Numerous localised extinctions of galaxiid species have been caused by the introduction of exotic salmonids and a number of freshwater galaxiid species are threatened with overall extinction by exotic salmonids (McDowall, 2006).

Contents 1 Genera 2 Fishing 3 Australian Galaxiid 3.1 South East Australian Mainland 3.2 Western Australian Galaxiid 3.3 Tasmanian Galaxiid 4 New Zealand Galaxiid 5 South American Galaxiid 6 South African Galaxiid 7 References 8 External links

Genera

There are about fifty species of galaxiid, grouped into seven genera:^[2]

• Aplochiton (2 species)
• Brachygalaxias (2 species)
• Galaxias (34 species)
• Galaxiella (3 species)
• Lovettia (1 species)
• Neochanna (6 species)
• Paragalaxias (4 species)

Fishing

The juveniles of those galaxiid that develop in the ocean and then move into rivers for their adult life are caught as whitebait while moving upstream and are much valued as a delicacy.

Adult galaxiids may be caught for food but they are generally not large. In some cases their exploitation may be banned (i.e. New Zealand) unless available to indigenous tribes.

In addition to serious impacts from exotic trout species, Australian adult galaxiids suffer a disregard from anglers for being "too small" and "not being trout". This is despite the fact that several Australian galaxiid species, though smallish, grow to a sufficient size to be catchable and readily take wet and dry flies, and that one of these species — spotted galaxias — was keenly fished for in Australia before the introduction of exotic trout species. A handful of fly-fishing exponents in Australia are rediscovering the pleasure of catching (and releasing) these fascinating Australian native fish on ultra-light fly-fishing tackle.

Australian Galaxiid

Galaxiid are found around the south eastern seaboard of Australia and in some parts of south western Australia. Species that are common to all areas are:

• Common galaxias or Jollytail galaxias, Galaxias maculatus
• Spotted galaxias, Spotted mountain trout, or Spotted minnow, Galaxias truttaceus

South East Australian Mainland

• Climbing galaxias, Galaxias brevipinnis
• Mountain galaxias, Galaxias olidus
• Flathead galaxias (Australia), Galaxias rostratus

Threatened species are:

• Barred galaxias, Galaxias fuscus (Victoria)
• Dwarf galaxias (Australia), Galaxiella pusilla (South Australia, Victoria)
• Tasmanian mudfish, Neochanna cleaveri (Wilson's Promontory, Victoria)

Western Australian Galaxiid

• Western galaxias, Galaxias occidentalis
• Mud minnow, Galaxiella munda
• Black-stripe minnow, Galaxiella nigrostriata

Tasmanian Galaxiid

15 species of Galaxiid have been found in Tasmania. The most common species are:

• Climbing galaxias, Galaxias brevipinnis
• Common galaxias, Galaxias maculatus
• Spotted galaxias, Galaxias truttaceus

While endangered species are:

• Saddled galaxias, Galaxias tanycephalus
• Pedder galaxias, Galaxias pedderensis
• Swan galaxias, Galaxias fontanus
• Swamp galaxias, Galaxias parvus
• Golden galaxias, Galaxias auratus
• Dwarf galaxias (Australia), Galaxiella pusilla
• Clarence galaxias, Galaxias johnstoni
• Tasmanian mudfish, Neochanna cleaveri
• Western paragalaxias, Paragalaxias julianus
• Great Lake paragalaxias, Paragalaxias eleotroides
• Arthurs paragalaxias, Paragalaxias mesotes
• Shannon paragalaxias, Paragalaxias dissimilis

New Zealand Galaxiid

19 species of galaxiid have been discovered in New Zealand. Most of these live in freshwater all their lives. However, the larvae of some species develop in the ocean where they form part of the plankton and return to rivers as juveniles where they develop and remain as adults.

Galaxiids in New Zealand are:

• Roundhead galaxias, Galaxias anomalus
• Giant kokopu, Galaxias argenteus
• Koaro or short-fin galaxias, Galaxias brevipinnis
• Lowland longjawed galaxias, Galaxias cobitinis
• Flathead galaxias, Galaxias depressiceps
• Dwarf galaxias, Galaxias divergens
• Eldons galaxias, Galaxias eldoni
• Banded kokopu, Galaxias fasciatus
• Gollum galaxias, Galaxias gollumoides
• Dwarf inanga, Galaxias gracilis
• Inanga, common galaxias or common jollytail, Galaxias maculatus
• Alpine galaxias, Galaxias paucispondylus
• Shortjaw kokopu, Galaxias postvectis
• Longjawed galaxias, Galaxias prognathus
• Dusky galaxias, Galaxias pullus
• Common river galaxias or Canterbury galaxias, Galaxias vulgaris
• Brown mudfish, Neochanna apoda
• Canterbury mudfish, Neochanna burrowsius
• Black mudfish, Neochanna diversus
• Northland mudfish, Neochanna heleios
• Chatham mudfish, Neochanna rekohua

South American Galaxiid

• Puyen, Galaxias maculatus (Chile and Argentina)

South African Galaxiid

• Cape galaxias, Galaxias zebratus (Cape Province, South Africa)

References

• McDowall, R.M. (2006) Crying wolf, crying foul, or crying shame: alien salmonids and a biodiversity crisis in the southern cool-temperate galaxioid fishes? Rev Fish Biol Fisheries 16: 233–422.

External links

• "New Zealand large galaxiid recovery plan, 2003-13: shortjaw kokopu, giant kokopu, banded kokopu, and koaro (Threatened Species Recovery Plan 55)". Department of Conservation, Wellington, New Zealand. 2004. http://www.doc.govt.nz/upload/documents/science-and-technical/TSRP55.pdf. Retrieved 2007-09-05. 
• "New Zealand non-migratory galaxiid fishes recovery plan (Threatened Species Recovery Plan 53)". Department of Conservation, Wellington, New Zealand. 2004. http://www.doc.govt.nz/upload/documents/science-and-technical/TSRP53.pdf. Retrieved 2007-09-19.