Passive dispersal has traditionally formed a fundamental component of biogeographical theories of the origin of the fauna that occupy the ice-free habitats of mainland Antarctica. But in the context of an emerging picture of endemism for many Antarctic terrestrial invertebrates, is there still a place for such stochastic processes in Antarctic biogeography? The case of the Antarctic fairy shrimp, Branchinecta gaini Daday 1910, may provide an answer - or, at least, an important exception to the rule. Although passive dispersal is certainly a stochastic and contingent phenomenon in Antarctica, the occurrence of B. gaini on the Antarctic Peninsula can only be explained satisfactorily by resort to this explanation. It is, at present, probably the best example of an Antarctic invertebrate with a biogeographic signature of passive - in particular, zoophoretic - dispersal.
