The subfamily Littorininae (Gastropoda: Littorinidae) in the temperate Southern Hemisphere: the genera Nodilittorina, Austrolittorina and Afrolittorina
The littorinine gastropods of the temperate southern continents were formerly classified together with tropical species in the large genus Nodilittorina. Recently, molecular data have shown that they belong in three distinct genera, Austrolittorina, Afrolittorina and Nodilittorina, whereas the tropical species are members of a fourth genus, Echinolittorina. Austrolittorina contains 5 species: A. unifasciata in Australia, A. antipodum and A. cincta in New Zealand, and A. fernandezensis and A. araucana in western South America. Afrolittorina contains 4 species: A. africana and A. knysnaensis in southern Africa, and A. praetermissa and A. acutispira in Australia. Nodilittorina is monotypic, containing only the Australian N. pyramidalis. This paper presents the first detailed morphological descriptions of the African and Australasian species of these three southern genera (the eastern Pacific species have been described elsewhere). The species-level taxonomy of several of these has been confused in the past; Afrolittorina africana and A. knysnaensis are here distinguished as separate taxa; Austrolittorina antipodum is a distinct species and not a subspecies of A. unifasciata; Nodilittorina pyramidalis is separated from the tropical Echinolittorina trochoides with similar shell characters. In addition to descriptions of shells, radulae and reproductive anatomy, distribution maps are given, and the ecological literature reviewed.