A consideration of the whitebait stage of Galaxias maculatus attenuatus (Jenyns)

Abstract

SUMMARYThe size composition of a season's catch of Galaxias maculatus attenuatus (Jenyns) whitebait is given. An analysis of consecutive catches shows that there is no overall increase in the size of the whitebait caught. This supports the theory that these fish have reached a physiological stage at which they migrate up accessible freshwater streams. The subsequent changes are so great that they warrant the term metamorphosis.The whitebait stages of other species of Galaxias are briefly compared.

Biology of the western minnow, Galaxias occidentalis Ogilby (Teleostei : Galaxiidae), in a south-western Australian river

“…5) indicate that the degree of hydration also has a marked influence on the size of mature oocytes. The egg diameters given by Hopkins (197 1) are also similar to those recorded by Benzie (1968) for G. vulgaris. Thus, diameters range from as high as 2.0 and 2.6 mm for eggs of G. vulgaris prior to and after release from the body cavity (Benzie, 1968a), to as low as c. 0.9 mm in the case of G. pusilla (Humphries, 1986) and 0.67 in one of the two studies on Neochanna apoda (Cadwallader, 1975).…”

Post‐settlement migratory behaviour and growth‐related costs in two diadromous fish species, Galaxias maculatus and Galaxias brevipinnis

“…Changes in feeding biology are also likely to occur during the immediate post‐settlement period (Benzie, 1968). Both G. maculatus and G. brevipinnis are opportunistic predators, feeding on mysids, amphipods and ostracods during their marine larval phase, but mainly aquatic insects as juveniles and adults (Merrick & Schmida, 1984; McDowall & Fulton, 1996).…”

Population studies of Galaxias maculatus (Jenyns) (Osteichthys: Galaxiidae) in Chile with reference to the number of vertebrae

“…These observations show that juveniles are abundant in the summer months in the lake (L) and estuary (H) populations. '"' Benzie (1968) and McDowall (1968) have demonstrated the'•'•shrinkage in juveniles as they change to adults in Galaxias maculatus. McDowall reports that this happens to the juveniles when they reach freshwater coming from the sea and most of the shrinkage is in the trunk.…”