Catalog Home Page

Didymozoid trematode infection of snapper, Pagrus auratus (Sparidae), off Western Australia: parasite population biology and fishery implications

Williams, A., Moran, M., Caputi, N. and Walters, C. (1993) Didymozoid trematode infection of snapper, Pagrus auratus (Sparidae), off Western Australia: parasite population biology and fishery implications. Fisheries Research, 16 (2). pp. 113-129.

Link to Published Version: http://dx.doi.org/10.1016/0165-7836(93)90047-B
*Subscription may be required

Abstract

A thread-like parasite which appears as conspicuous yellow bundles in the flesh of the important commercial and recreational snapper, Pagrus auratus, were found to be a didymozoid trematode, Gonapodasmius williamsoni. A survey of snapper and other commercial reef fish off the northwestern coast of Western Australia in the vicinity of Shark Bay revealed that the overall prevalence of this flatworm parasite in snapper was 5.4%. Very few infections were large enough to be noticed in fillets by processors. The parasite is unlikely to be pathogenic to humans because only the non-infective adult stage of the worm occurs in snapper. Fish age (size) was found to be directly correlated with the prevalence of infection, with 5 to 8-year old specimens most frequently infected. Pigmented scars found in the flesh of snapper were found to be G. williamsoni in various stages of degeneration. The relationships between scar and worm prevalence and fish age permitted the development of a model of the dynamics of parasite infection in the snapper stock. This model estimated that parasite mortality was high, with 57% of snapper losing their infections annually. Scar tissue is persistent in the skeletal muscle with an estimated 14% of fish eliminating scar tissue annually. The implications of the parasite and its infection dynamics are discussed in regard to marketing of snapper and the use of didymozoid parasites as biological markers in fish population studies

Publication Type: Journal Article
Murdoch Affiliation: School of Biological and Environmental Sciences
Publisher: Elsevier BV
URI: http://researchrepository.murdoch.edu.au/id/eprint/34216
Item Control Page Item Control Page