The objectives of this study were to provide detailed information on the morphometrics and reproductive biology of the Australian native redclaw crayfish, Cherax quadricarinatus, outside its native range, and to study its diet and interactions with a review of potential biocontrol of invasive thiarid snails. Crayfishes were collected monthly using baited traps from two major river systems in Jamaica over a 12-month period (June 2003 to May 2004). Cherax quadricarinatus displayed sexual dimorphism with significant variation in carapace and chela lengths as well as chela widths between males and females. Fecundity was size-dependent. Ovigerous females were found year-round in Jamaica. Cherax quadricarinatus is an opportunistic omnivore with little difference in diet across sex and size classes, temporally or spatially. While size-specific gastropod predation was displayed in experiments, with introduced snails (of the family Thiaridae) chosen over native snails (of the family Physidae), stomach content analysis revealed that gastropods were not a major component of crayfish diet in the wild. Detritus was the main component of C. quadricarinatus diet in both river systems. However, under experimental conditions, the species exhibits a preference for macrophytes; this may indirectly affect the benthic invertebrate communities in rivers by reducing the available food and vegetative substrate.