Morphological variations among populations of Bulinus forskalii (Ehrenberg, 1831) from Cameroon

Abstract

ABSTRACT Climatic stratification from equatorial rainforest to Sahelian savannah in Cameroon implies successive bioclimatic ecosystems, various natural and artificial situations that may generate morphological and genetic adaptation of populations of Bulinus forskalii (Ehrenberg, 1831) which is widely distributed throughout the country. The present research was undertaken on 955 snails sampled from 12 populations along a south–north transect to investigate morphological variations of shells. Shell colour varied from dark brown to whitish with Sudano–Sahelian shells being brownish through to whitish, shouldered and strongly carinate. Morphometric characters varied greatly from one population to another, with all shell parameters being highly correlated to shell height. Sudano–Sahelian shells were smaller than equatorial shells. From Sangmélima in the equatorial forest region to Marao in the Sudano–Sahelian region a gradual decrease of shell dimensions was apparent, indicating a morphocline. This could reflect the role played by ecological factors on snail population dynamics.