Observations on the ecology of four species of the genus Paragalaxias (Pisces : Galaxiidae) from Tasmania

Abstract

A study was made of the life history and diet of P. dissimilis Regan and P. eleotroides McDowall & Fulton from Great Lake, Tasmania. Some data on P. mesotes McDowall & Fulton from Arthurs Lake and P. julianus McDowall & Fulton from the Julian Lakes and Lake Field are also given. P. dissimilis matured at 1 year old and spawning took place in summer. Eggs numbered between 39 and 179 and were deposited in communal clusters on protected rock surfaces around the shores of Great Lake. Newly hatched larvae of this species were active and fully developed but were not found in the adult habitat until 6 months after spawning. P. eleotroides also matured at 1 year old but spawned in spring. Egg numbers ranged from 44 to 149 but the spawning site of this species was not found. No large influx of juvenile P. eleotroides was detected. Length- and weight-frequency histograms of P. dissimilis are figured and length-weight relationships of all four species are given. The diet of P. dissimilis varied seasonally as well as between different size groups. Differences in diet also occurred between P. dissimilis and P. eleotroides.