Tasmanian mudfish

Tasmanian mudfish
Tasmanian mudfish
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Osmeriformes
Family: Galaxiidae
Subfamily: Galaxiinae
Genus: Neochanna
Species: N. cleaveri
Binomial name
Neochanna cleaveri
(Scott, 1934)

The Tasmanian mudfish, Neochanna cleaveri, is a small Australian amphidromous fish in the galaxiid family, of the order Osmeriformes.

Contents

Distribution

N. cleaveri is found in coastal wetlands of south eastern Australia: around Tasmania, Flinders Island in Bass Strait and southern Victoria particularly Wilsons Promontory.[1][2] There are isolated populations in the Otways, near Geelong and Melbourne in Victoria as well as in far eastern South Australia near Naracoorte.[3] The fish's range has been significantly reduced, especially in Victoria, due to destruction of suitable habitat through human activity such as swamp reclamation and drainage.[2]

Description

Typically galaxiid in form, scaleless with an elongate, tubular body, and moderately sized mouth.[1][2] May be distinguished from other galaxiid species by the small eye and the blunt, rounded head shape with protuding tubular nostrils over the upper lip.[1] Pectoral fins are rounded.[1][2] The pelvic fins are small and set at about the mid point of the fish's length and the dorsal and anal fins are set right back with the dorsal fin slightly ahead of the anal.[1][2] Caudal fin rounded with well-developed flanges along the caudal peduncle reaching nearly to the posterior edges of the dorsal and anal fins.[1][2] Greenish brown in colour, sometimes golden, greyish on the ventral survaces.[1][2] Marked with irregular darker mottled bands and blotches over the back, sides and the fin bases.[1][2] Its length is up to 140 mm, commonly to 80 mm.[1][2]

Habitat

Found mostly in muddy swamps, marshes and drains with heavy vegetation.[1][2] The fragmented populations in Victoria are likely to be remnants of a larger continuous population pre European settlement.[2]

Importance to humans

Although individuals would be taken as part of the Tasmanian whitebait fishery, the numbers of this species involved is likely to be quite small.[2] Adapts well to captivity and is easy to keep, but is secretive and nocturnal. limiting its appeal.[2]

Conservation status

Not listed nationally as threatened due to their relative abundance in Tasmania.[3] The fish is however, listed in Victoria as critically endangered under the Victorian Flora and Fauna Guarantee Act.[4]

Life-cycle

Spawning in late winter, the hatched larvae are washed out to sea spending approximately 2 to 3 moths at sea or in esturies before returning to freshwater as part of the whitebait migration. Tasmanian mudfish are smaller than other species comprising the whitebait fishery, generally only 30 to 40 mm at this age. The juvenile fish migrate upstream to their usual habitat as mentioned above. Nocturnal in habit and secretive in nature, the fish usually rest during daylight hours in heavy vegetation or half buried in the muddy substrate. N. cleaveri can aestivate if water in its location dries up in summer or in times of drought, burying horizontally in the mud or by seeking out moist areas of substrate under rocks and logs.[1][2]

Naming

Other common names: Australian mudfish,[3] mud trout,[2] mud galaxias[2]

Other scientific names: Galaxias cleaveri,[1][2] Saxilaga cleaveri,[2] Saxilaga anguilliforms[2] and Galaxias upcheri[2]

The genus Neochanna is derived from the Greek Neos meaning new and Channa an Asian genus of aestivating fishes.[3] The species name is derived from the fish's original collector Mr F. Cleaver.[3]

Citations

  1. ^ a b c d e f g h i j k l Allen, Midgley & Allen, 2002
  2. ^ a b c d e f g h i j k l m n o p q r s t McDowell, 1980
  3. ^ a b c d e Department of the Environment, Water, Heritage and the Arts
  4. ^ Department of Sustainability and Environment (2007)

References

See also

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