Pedder galaxias - Galaxias pedderensis
By Jean Jackson
Threatened Fish Profile – In Newsletter 29_2, December 1999
(Drawing by Carol Kroger from “Tasmanian Freshwater Fishes” by Wayne Fulton)
Conservation Status:
Endangered (ASFB, Tasmania, Commonwealth), Critically Endangered (IUCN).
Description:
Probably the most endangered freshwater fish species in Australia. The Pedder galaxias is a native freshwater fish that grows to a maximum length of about 160 mm.
They have a slender elongate body and dorsally flattened head. The back and sides
are light yellow-brown in colour with gold iridescent flecks and irregular blackishbrown blotches (Hamr, 1995).
Life History:
Pedder galaxias are confined to freshwater and spawn in spring (mid-October) as
water temperatures begin to rise. In an artificial stream, captive fish laid their eggs
under flat rocks, aquatic vegetation and woody debris. As in other entirely freshwater galaxias in Tasmania, a relatively small number of large eggs is produced, ranging from about 150-1200 depending on the size of the female. Size at maturity is
~95 mm fork length in females and ~75 mm fork length in males (Hamr, 1992).
Distribution and Habitat:
The Pedder galaxias is endemic to Tasmania and naturally occurred only in the
original Lake Pedder and tributary streams. It is apparently now extinct in what remains of its natural habitat (tributaries of the Lake Pedder impoundment) as no individuals have been found since 1996 despite intensive searches each summer. The
species now survives only as a translocated population in the Western Arthur Range
south-west of Lake Pedder. The last fish to be found in the natural habitat lived in
the lower meandering sections of two tributary streams, preferring areas where the
streams are heavily shaded, sandy-bottomed and highly convoluted with deep pools
and instream cover. The diet of the Pedder galaxias consists mainly of aquatic insect
larvae, aquatic beetles, small crayfish and copepods (Hamr, 1992).