The Australian smelt (''Retropinna semoni'') is a small,

pelagic The pelagic zone consists of the water column of the open ocean and can be further divided into regions by depth. The word ''pelagic'' is derived . The pelagic zone can be thought of as an imaginary cylinder or water column between the sur ...

silvery

freshwater Fresh water or freshwater is any naturally occurring liquid or frozen water containing low concentrations of dissolved salts and other total dissolved solids. The term excludes seawater and brackish water, but it does include non-salty mi ...

fish A fish (: fish or fishes) is an aquatic animal, aquatic, Anamniotes, anamniotic, gill-bearing vertebrate animal with swimming fish fin, fins and craniate, a hard skull, but lacking limb (anatomy), limbs with digit (anatomy), digits. Fish can ...

found in large numbers in waters of the south eastern

Australia Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller isl ...

n mainland.

Distribution

The fish is endemic to Australia and widely distributed through the coastal drainages of the south eastern part of the mainland. The species is found in coastal drainages from the south east corner of

South Australia South Australia (commonly abbreviated as SA) is a States and territories of Australia, state in the southern central part of Australia. With a total land area of , it is the fourth-largest of Australia's states and territories by area, which in ...

through Victoria,

New South Wales New South Wales (commonly abbreviated as NSW) is a States and territories of Australia, state on the Eastern states of Australia, east coast of :Australia. It borders Queensland to the north, Victoria (state), Victoria to the south, and South ...

to the Fitzroy River in south east

Queensland Queensland ( , commonly abbreviated as Qld) is a States and territories of Australia, state in northeastern Australia, and is the second-largest and third-most populous state in Australia. It is bordered by the Northern Territory, South Austr ...

. It occurs widely in the

Murray River The Murray River (in South Australia: River Murray; Ngarrindjeri language, Ngarrindjeri: ''Millewa'', Yorta Yorta language, Yorta Yorta: ''Dhungala'' or ''Tongala'') is a river in Southeastern Australia. It is List of rivers of Australia, Aust ...

and its tributaries and up the Darling as far upstream as

Wilcannia Wilcannia is a small town located within the Central Darling Shire in north western New South Wales, Australia. Located on the Darling River, the town was the third largest inland port in the country during the river boat era of the mid-19th c ...

. There are isolated populations in the Coopers Creek which drains into

Lake Eyre Lake Eyre ( ), officially known as Kati Thanda–Lake Eyre, is an endorheic lake in the east-central part of the Far North (South Australia), Far North region of South Australia, some 700 km (435 mi) north of Adelaide. It is the larg ...

and several smaller ones in north-western

and southern Queensland. Recent genetic research indicates Australian smelt stocks are composed of 5 highly genetically distinct and as yet undescribed species (Hammer ''et al.'', 2007).

Description

A small silvery fish to 75 mm total length, very occasionally to 100 mm. In Coopers Creek usually only to 50 mm. It is clear to purple-olive on the back, translucent with a silver streak along the sides, sometimes with orange highlights, and has colourless fins. Captively raised specimens will easily exceed 100mm and live for longer periods than their wild counterparts.

Habitat

Often found in large schools of thousands, this pelagic species prefers slow moving or still waters. It is often found in billabongs,

dam A dam is a barrier that stops or restricts the flow of surface water or underground streams. Reservoirs created by dams not only suppress floods but also provide water for activities such as irrigation, human consumption, industrial use, aqua ...

s and

lake A lake is often a naturally occurring, relatively large and fixed body of water on or near the Earth's surface. It is localized in a basin or interconnected basins surrounded by dry land. Lakes lie completely on land and are separate from ...

s at various salinity levels and in the lower reaches of

river A river is a natural stream of fresh water that flows on land or inside Subterranean river, caves towards another body of water at a lower elevation, such as an ocean, lake, or another river. A river may run dry before reaching the end of ...

s and

stream A stream is a continuous body of water, body of surface water Current (stream), flowing within the stream bed, bed and bank (geography), banks of a channel (geography), channel. Depending on its location or certain characteristics, a strea ...

s. Although there have been some reports of diadromous populations, this fish usually completes its entire life cycle in

. They shoal near the surface and around the cover of aquatic plants and woody debris.

Diet

A carnivorous fish, the Australian smelt feeds mostly on small

invertebrate Invertebrates are animals that neither develop nor retain a vertebral column (commonly known as a ''spine'' or ''backbone''), which evolved from the notochord. It is a paraphyletic grouping including all animals excluding the chordata, chordate s ...

s such as

aquatic insect Aquatic insects or water insects live some portion of their life cycle in the water. They feed in the same ways as other insects. Some ''diving'' insects, such as predatory diving beetles, can hunt for food underwater where land-living insects ...

s and microcrustaceans, and a variety of

planktonic Plankton are the diverse collection of organisms that drift in water (or air) but are unable to actively propel themselves against currents (or wind). The individual organisms constituting plankton are called plankters. In the ocean, they pro ...

organisms.

Reproduction

Spawns in spring at water temperatures in excess of 15 °C. Eggs are demersal, adhesive, spherical and transparent, about 0.8 mm diameter to 1 mm when water hardened. Eggs fall to the bottom and stick to instream debris, vegetation and the substrate. Females lay between 100 and 1000 eggs. Hatching occurs at about 9 to 10 days and larvae are around 4.5 to 5 mm total length.

Importance to humans

This species has some potential as an

aquarium An aquarium (: aquariums or aquaria) is a vivarium of any size having at least one transparent side in which aquatic plants or animals are kept and displayed. fishkeeping, Fishkeepers use aquaria to keep fish, invertebrates, amphibians, aquati ...

species. Ideally suited to use as an effective

mosquito Mosquitoes, the Culicidae, are a Family (biology), family of small Diptera, flies consisting of 3,600 species. The word ''mosquito'' (formed by ''Musca (fly), mosca'' and diminutive ''-ito'') is Spanish and Portuguese for ''little fly''. Mos ...

predator in

pond A pond is a small, still, land-based body of water formed by pooling inside a depression (geology), depression, either naturally or artificiality, artificially. A pond is smaller than a lake and there are no official criteria distinguishing ...

s in south eastern

, especially where

frog A frog is any member of a diverse and largely semiaquatic group of short-bodied, tailless amphibian vertebrates composing the order (biology), order Anura (coming from the Ancient Greek , literally 'without tail'). Frog species with rough ski ...

s are encountered. Not suitable for use in a community tank, best kept as a school of fish in a single species situation.

References

* * * Michael P. Hammer, Mark Adams, Peter J. Unmack and Keith F. Walker (2007) A rethink on Retropinna: conservation implications of new taxa and significant genetic sub-structure in Australian smelts (Pisces : Retropinnidae). ''Marine and Freshwater Research'' 58: 327–341.

External links

Australian Smelt video on Youtube

Native Fish Australia
{{Taxonbar, from=Q2207695 Australian smelt Freshwater fish of Australia Taxa named by Max Carl Wilhelm Weber Australian smelt