An appraisal of the diversity and distribution of large branchiopods (Branchiopoda: Anostraca, Laevicaudata, Spinicaudata, Cyclestherida, Notostraca) in Australia

Abstract

The diversity of large branchiopods in Australia has not be reviewed since 1983 for fairy and brine shrimps (Anostraca), 2005 for clam shrimps (Laevicaudata, Spinicaudata, Cyclestherida), and 1955 for shield shrimps (Notostraca). Presently five genera and 59 species of anostracans are known to occur in Australia (up from three genera and 29 species in 1983), with 35 described species plus five known undescribed species of Branchinella, 18 described plus one known undescribed species of Parartemia, two described species of Streptocephalus, two species of Australobranchipus, and two Artemia. Of these Branchinella clandestina and Streptocephalus queenslandicus could be junior synonyms and hence invalid. A few species are widespread (B. australiensis, B. occidentalis, B. affinis), but the majority are restricted to a state or two and many are localised. All species of Parartemia and a few Branchinella are halobionts, while the remainder live in strictly fresh waters. Debate rages on whether one of the two international species of Artemia are native or introduced. The degree of congeneric occurrences varies between genera and across the continent. The clam shrimp fauna is less well known with at least two species of Lynceus, two of Eocyzicus, six of Caenestheria, two of Caenestheriella, an enigmatic species supposedly belonging to Cyzicus, seven of Limnadia, two of Eulimnadia, eight of Limnadopsis, one of Eoleptestheria, and one of Cyclestheria. Two further species of Lynceus, four of Limandia and four of Limnadopsis are being described. This makes 42 species, up from 26, but descriptive and molecular work in progress suggest many more at least in the four genera being studied (Lynceus, Eocyzicus, Caenestheriella, Limnadia). Eocyzicus parooensis and an undescribed species of Limnadia are halophilic. For the Notostraca, the supposedly widespread Triops australiensis and Lepidurus apus viridis may represent many species separable molecularly.