Movement and stock structure of narrow-barred Spanish mackerel as indicated by parasites

Data from permanent parasites (juvenile trypanorhynchs and anisakids) indic ated that Spanish mackerel Scomberomorus commerson from four sites on the w est coast of Australia, Abrolhos, Shark Bay, Exmouth and Onslow, intermingl ed and were probably all drawn from the same stock. Fish from Broome, Kupan g (Indonesia), Groote Eylandt-Torres Strait and the cast coast of Australia had distinct faunas of permanent parasites and probably each belonged to a different stock. There was evidence of movement of fish between Broome and the west coast. Abundances of temporary parasites (gill copepods and monog eneans) suggested that males and females on the west coast migrated separat ely because in several cases the parasite fauna of one sex was more similar to that of fish in an adjacent area than to the opposite sex in the same a rea. (C) 2001 The Fisheries Society of the British Isles.