Roundhead galaxias

Taxobox
name = Roundhead galaxias
regnum = Animalia
phylum = Chordata
classis = Actinopterygii
ordo = Osmeriformes
familia = Galaxiidae
subfamilia = Galaxiinae
genus = "Galaxias"
species = "G. anomalus"
binomial = "Galaxias anomalus"
binomial_authority = Stokell, 1959

The roundhead galaxias, "Galaxias anomalus", is a galaxiid of the genus "Galaxias", found only in the Taieri and Clutha catchments in Otago, New Zealand. It grows to a length of up to 13 cm.

The roundhead galaxias has 16 caudal fin rays, and this is used to distinguish it from dusky galaxias "Galaxias pullus" (14 fin rays), and Eldons galaxias "Galaxias eldoni" (15 fin rays), both of which also occur in the Taieri River catchment.

The single dorsal and anal fins are rounded, and set back about three quarters of the body length. The pelvic fins are about half way along the underside of the body. Like all galaxiids it lacks scales and has a thick, leathery skin covered with mucus. Colouring is irregular dark brown markings on a light brown background.

Roundhead galaxias occupy a diverse range of low gradient streams, from small weedy drains to braided cobble streams. They are tolerant of high water temperatures and low flows, surviving droughts by living in remnant pools that remain in ephemeral streams. They are non-diadromous and therefore do not have a marine phase and is not part of the whitebait catch.

References

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* [http://www.niwascience.co.nz/rc/freshwater/fishatlas/species/roundhead_galaxias NIWA June 2006]