Infraspecific variations within the Atyidae: A study of morphological variation within a population of Paratya australiensis (Crustacea : Decapoda)

Abstract

The extent of variation in 55 taxonomic attributes (including all those of major taxonomic significance in the Atyidae) was investigated in a single population of P. australiensis. The aim was to provide insight to the nature of infraspecific variation in atyid species since some characters used to diagnose species are known to vary within a species. No attributes varied significantly with season. Sexual variation occurred in five proportional attributes as well as in secondary sex characters. Size variation was statistically significant in six proportional attributes. and for several numerical attributes not only was it highly significant statistically but also the ranges of values overlapped little between successive size classes. Rostral armature and the relative depth of the rostrum varied widely irrespective of season, sex and total body length. The results indicate the need for caution in diagnosis of atyid species.