Evidence for predation as a factor in determining shell color frequencies in a mangrove snail Littorina sp. ( Prosobranchia: Littorinidae).

Abstract

Postulated that in Littorina populations living on Avicennia marina in Moreton Bay, Queensland, yellow shelled individuals are at selective advantage over other shell colors and that this advantage is due to differential selection by predators. A combination of selection for crypsis and for the less common morph is suggested as the mechanism maintaining the high levels of variation in this species. -from Authors