LARVAL DEVELOPMENT OF PARATYA-AUSTRALIENSIS KEMP, 1917 (DECAPODA, CARIDEA, ATYIDAE), REARED IN THE LABORATORY, WITH COMPARISONS OF FECUNDITY AND EGG AND LARVAL SIZE BETWEEN ESTUARINE AND RIVERINE ENVIRONMENTS

The larval development of Paratya australiensis consisted of 8 stages and lasts between 28 and 45 days in the laboratory. Stages I-IV were r egular, but stages V-VIII were irregular with ''mark-time molts'' and a ''skipped stage'' common. Metamorphosis occurred after 7-12 ecdyses. This development is intermediate between the abbreviated development of Caridina spp. and the extended development of other atyids. Eggs an d early stage larvae were larger and brood sizes were smaller in P. au straliensis collected from riverine locations than those collected fro m an estuarine location in the same river system. There were no differ ences in development between laboratory-reared larvae from the two hab itat types. The apparent plasticity of development is discussed in rel ation to environmental conditions.