Distribution of migratory fishes and shrimps along multivariate gradients in tropical island streams

Among the 16 species of fishes and shrimps studied at 51 sites along several small streams at Basse Terre, Guadeloupe, Lesser Antilles, more than 60% showed a spatial distribution significantly influenced by environmental conditions. These included altitude, basin size, terrestrial vegetation and land use. However, the range of the species habitat was generally high, except for three species limited to the downstream stretches (two fishes and one shrimp). The habitat characteristics of fish and shrimp species tended to differ, but the difference was not significant (P<0·05). On the contrary, the habitat characteristics of amphidromous and catadromous species clearly differed, with a lower occurrence at the most elevated sites of catadromous species than amphidromous species.