A revision of the Genus Galaxias : (Pisces: Galaxiidae) in Tasmania

Eight species of the genus Galaxias are found to be represented in Tasmania. The taxonomy, meristic and morphometric variation of each species is examined and data on the distribution, life history and ecology of each species are presented together with references and synonomy. Excluding the two genera Paragalaxias and Brachygalaxias, which are outside the scope of the present work, a total of twelve species and one subspecies in two genera, Galaxias and Saxilaga, have been recorded from Tasmania at the time of writing. G. scopus Scott is shown to be a synonym of G. truttaceus Valenciennes while G. affinis Regan and G. coxii Macleay are found to be synonyms of G. brevipinnis Ganther, which is recorded for the first time from the Australian mainland. The two species currently referred to the genus Saxilaga Scott, together with G. upcheri Scott, are found to represent one species only. As this species appears to possess no features which warrant generic separation from Galaxias the species is accordingly referred to that genus. The genus Saxilaga Scott thus comes to be abandoned. The type locality of G. auratus is shown to be Lake Sorell and the type locality of G. upcheri is more accurately defined than has been done by previous writers. The Tasmanian galaxiid fauna is broadly divisible into two groups based on life history and ecology patterns. The first group comprises the wide ranging diadromous species which inhabit the coastal areas, including the offshore islands, and are also found on the Australian mainland. The second group of species is largely restricted to specialised lacustrine and fluviatile areas of the inland and central region. In some cases however considerable overlap in the ranges of both groups is evident, 2. as in the case of G. brevipinnis, in which both diadromous and lacustrine populations were found to occur. The Tasmanian members of the genus Galaxias were found to be divisible into four species groups. The first group consists of G. maculatus and G. cleaveri. The second group consists of G. truttaceus and the closely related species G. auratus. The third group contains the single species G. brevipinnis while the last group comprises the three inland species G. johnstoni, G. pedderensis and G. parvus. The Tasmanian galaxiid fauna is compared and contrasted with the galaxiid faunas of Australia and New Zealand and the distribution patterns and zoogeographic considerations are discussed.