Meeting Abstract

S10-2.2  Saturday, Jan. 7  The biogeography of Australian barnacles JONES, D.S.; Western Australian Museum

Two biogeographic provinces are distinguished for Australian waters, a northern tropical province and a southern temperate province. The barnacle fauna of the northern tropical province exhibits high species diversity, a high incidence of tropical species and a low species endemicity. In comparison, the barnacles of warm-temperate and temperate southern Australian waters show decreased species diversity, a lower incidence of tropical species and a higher species endemicity. General patterns can be demonstrated for the shallow-water biota of northern tropical and the southern temperate Australian provinces, with members of the balanomorph families Chthamalidae, Tetraclitidae and Balanidae dominant. However, in south-western Australia, a stronger tropical component than could be predicted by latitude occurs, due to the influence of the Leeuwin Current, a seasonal, poleward flowing, eastern boundary current on the western coast of Western Australia. Additionally, chthamalids are absent from south-western Australian shores and zonation shows a simpler tetraclitid-balanid trend, with archaeobalanids also prominent on sheltered shores. In both tropical and temperate Australia the pedunculate barnacle component is greater in the sub-littoral, the majority of species being epizoic on a variety of hosts. Pedunculate species diversity in the temperate littoral and sub-littoral is not as great as that occurring in corresponding zones in the tropics. Pelagic species in both provinces are pedunculate forms. Introduced species are identified from port localities in tropical and temperate provinces.