Occurrence and influence of bopyrid parasites on female penaeid prawns from coastal waters of central Queensland (Australia)

Abstract

The prevalence of bopyrid isopods, parasitic on penaeid prawn hosts, is recorded for the first time from a central Queensland prawn trawl fishery. The bopyrid parasite Parapenaeon prox. expansus has been recorded for the first time from the red spot king prawn, Penaeus longistylus, and the blue-legged king prawn, Penaeus latisulcatus. Previous unpublished reports of Parapenaeon japonicum parasitizing P. longistylus have also been substantiated. Parasite species were not randomly associated with all prawn species but rather were associated with a single prawn host species or species group. The factors that give rise to such specific host-parasite associations, particularly the host-selective behaviour of the parasite and the habitat preferences of the juvenile prawns, are discussed. Bopyrids had no significant effect on the weight of the prawns, but they did have a significant effect on ovary weight and histology, causing sterility in their hosts. High levels of infestation have been recorded from other fisheries (resulting in reduced spawning potential of the host population), but the low prevalence (0.32%) of bopyrid parasites in central Queensland prawns appears to be so low as not to present a concern at present.