The Clarence galaxias (''Galaxias johnstoni'') is a species of

fish Fish are aquatic, craniate, gill-bearing animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish as well as various extinct related groups. Approximately 95% of li ...

in the family Galaxiidae

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

Tasmania ) , nickname = , image_map = Tasmania in Australia.svg , map_caption = Location of Tasmania in AustraliaCoordinates: , subdivision_type = Country , subdi ...

Description

The Clarence galaxias is scaleless and has a dark brown back with brown bars and bands extending down its sides, while the belly is a lighter yellow-cream color. Adults reach a body length of 12.5–14 cm and a maximum weight of 20 g.

Distribution and habitat

The Clarence galaxias is a freshwater

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

and inhabits lakes as well as swamps and streams connected to lakes. It is endemic to Tasmania's Derwent River catchment, including the Clarence Lagoon. Only seven breeding populations are currently known.

Conservation

While locally common, the species has been classified as

endangered An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching and inva ...

by the

IUCN The International Union for Conservation of Nature (IUCN; officially International Union for Conservation of Nature and Natural Resources) is an international organization working in the field of nature conservation and sustainable use of natu ...

. It is under pressure from

predation Predation is a biological interaction where one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not kill the ...

and competition from introduced

brown trout The brown trout (''Salmo trutta'') is a European species of salmonid fish that has been widely introduced into suitable environments globally. It includes purely freshwater populations, referred to as the riverine ecotype, ''Salmo trutta'' morph ...

and

rainbow trout The rainbow trout (''Oncorhynchus mykiss'') is a species of trout native to cold-water tributaries of the Pacific Ocean in Asia and North America. The steelhead (sometimes called "steelhead trout") is an anadromous (sea-run) form of the coasta ...

Behavior

This Galaxia is an ambush predator. They burrow or find a lair to predate from. Unless food is bountiful they show vigor and are aggressive during feeding .They tend to perch themselves on top of structures such as rocks using their pectoral fins regularly. They are more active during the evening. The foods observed eaten are only live foods such as nymphs, mosquito larve, and brine shrimp. Blood worms are an exception and also eaten frozen. Upon further observation, they clunkily get around swimming, turning their body they seem stiff in the mid section. They have tremendous strength relative to size with a thick front section, large gaping jaw and large fan like fins.

References

Clarence galaxias The Clarence galaxias (''Galaxias johnstoni'') is a species of fish in the family Galaxiidae Endemism, endemic to Tasmania. Description The Clarence galaxias is scaleless and has a dark brown back with brown bars and bands extending down its sid ...

Freshwater fish of Tasmania River Derwent (Tasmania) Critically endangered fauna of Australia

Taxonomy articles created by Polbot

thumb The thumb is the first digit of the hand, next to the index finger. When a person is standing in the medical anatomical position (where the palm is facing to the front), the thumb is the outermost digit. The Medical Latin English noun for thumb ...

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