The Gastropods in the streams and rivers of five Fiji islands: Vanua Levu, Ovalau, Gau, Kadavu, and Taveuni / by A. Haynes

Abstract

Streams and rivers on the islands of Vanua Levu, Ovalau, Gau, Kadavu and Taveuni, Fiji, were investigated for gastropods, water conductivity, water hardness, temperature, substrate, and current speed during 1983 and 1984. As at other Indo-Pacific islands there was a diverse and abundant lotic gastropod fauna. Twenty-six species were collected on Vanua Levu and 13-16 species were found in each torrential stream studied on the other four islands. Upstream, above the influence of the tide, both the longitudinal and horizontal distributions of gastropods appeared to be mainly dependent on the water speed and type of substrate. A suspected new species of Acochlidium (Opisthobranchia) was discovered on the island of Vanua Levu.