DISTRIBUTION OF 4 RECENTLY DISCOVERED GALAXIID SPECIES IN THE TAIERI RIVER, NEW-ZEALAND - THE ROLE OF MACROHABITAT

The physical features of 20 streams inhabited by four recently discove red species of allopatric, non-migratory galaxiid fishes in the Taieri River, South Island, New Zealand were examined. Significant differenc es in particle size frequencies, combined waterfall frequency, channel depth variation and stream width : flood channel width ratios, indica ted that Galaxins anomalus lived in low gradient shallow streams where as G. depressiceps and G. eldoni occupied low to high gradient streams with more variability in depth. Climbing ability differed significant ly among the species. Their allopatric patterns of distribution were, in part, the probable consequence of the abilities of G. depressiceps and G. eldoni to colonize areas that G. anomalus could not penetrate. Historical factors and reproductive biology of the four species are hy pothesized also to be causal determinants of their current distributio ns. (C) 1997 The Fisheries Society of the British Isles.