The non-marine molluscs of the Cape Range peninsula, Western Australia

WA Museum Records and Supplements | Updated 9 years ago

Abstract: The extant non-marine molluscan fauna of the Cape Range peninsula, Western Australia, consists of two species of aquatic prosobranch gastropods and 16 specIes of terrestrial pulmonates. The fauna contains a high proportion of endemic taxa with ninc camacnid and one pupillid species being endemic to the Cape Range peninsula (56% of all species). Of these, seven camacnids (39% of all species) are endemic to the plateau and slopes of Cape Range itself. The Cape Range peninsula populations of four of the remaining eight species are at the southern limits of the species ranges (22% of all species). The only fossil of a non-marine mollusc known from this area is of a species of the bulimulid genus Bothriembryon.

Available information on the biology of these and related species from the Cape Range peninsula is discussed with reference to the environment of the area and its amelioration within the limestone caves of the range and its eoastal plains. Three widespread non-camaenid species (Discocharopa aperta, Eremopeas interioris and Stenopylis coaretata), which are here at the southern limits of their ranges, have here been found living exclusively in caves although elsewhere they are not generally cavernicolous. This habitat restriction of the disjunct Cape Range populations supports the hypothesis that they are relictual.