Land snail species richness in a cocoa agroforest in Ile-Oluji, Ondo State, Nigeria

Abstract

The need to preserve traditional agro-forestry for bio-diversity conservation in Nigeria has become of utmost importance. The land snail community of an agro-forest in Ile-Oluji, Ondo State, Nigeria, was studied using a combination of direct search and leaf litter sieving techniques. A total of 33 species and 875 individual snails belonging to 10 molluscan families were collected from 9 plots of 400 m2 each. Sixty-five to 129 individual snails were collected per plot and the species richness varied from 13 to 24. The most abundant snails numerically (74%), were the detrivorous, family Subulidae, while the members of the carnivorous, Streptaxidae, contributed about 60% to species richness. The streptaxid genus Gulella was the most speciose while the most abundant species was the Gulella io, contributing 13% of the total number of individuals. Trachycystis sp. (Charopidae) was recorded for the first time in Nigeria. The land snail species composition in Ile-Oluji agroforest is similar to that recorded from primary forest reserves and old-growth forests in Nigeria. The land snail species inventory will increase our knowledge of the molluscan fauna of the forest region and assist in conservation management.

Keywords: molluscs, bio-diversity, Ile-Oluji, agro-forestry, Nigeria

The Zoologist, 10:40-47 (2012)