LOXOTHYLACUS IHLEI BOSCHMA, (RHIZOCEPHALA) AND ITS EFFECTS ON THE MUDCRAB SCYLLA-SERRATA (FORSKAL), IN NORTHERN AUSTRALIA

Loxothylacus ihlei, a rhizocephalan parasite of the mud crab, Scylla s errata (Forskal), is reported for the first time in Australian waters. The parasite is described and found to be variable in a number of cha racters. Most infected S. serrata, collected from commercial catches i n the Northern Territory, Australia, were significantly smaller than u ninfected crabs, and their abdominal flaps were relatively larger than those of mature females. Annual prevalence of infection was low (2.1% ), with the monthly variation ranging from negligible early in the yea r to around 7% in November.