A rediagnosis of Athanopsis australis Banner & Banner, 1982, a rare alpheid shrimp from southern Australia, with a phylogeny of Athanopsis Coutiere, 1897 and remarks on antitropical distributions in the Alpheidae (Decapoda, Caridea)

The rare alpheid shrimp, Athanopsis australis Banner & Banner, 1982, currently known from only four specimens from Victoria, Australia, is redescribed based on three specimens collected since the original description of the incomplete holotype. The major cheliped, missing in the holotype, is described for the first time; the minor cheliped, however, remains unknown. Contrary to the original description and illustrations, the telson of the holotype and of all recently collected specimens bears two pairs of small dorsal spines, as in all Athanopsis species. The apparent rarity of A. australis and other Athanopsis species may be due to their infaunal life style: at least two species live "commensally" in echiuran burrows. A preliminary phylogenetic analysis of Athanopsis based on morphological and colour pattern characters suggests that A. australis and A. dentipes Miya, 1980 from Japan are sister species with antitropical distribution.