Metazoan parasites of yellowtail kingfish, Seriola lalandi lalandi, in New Zealand: Prevalence, intensity, and site preference

The prevalence and intensity of metazoan ectoparasites on the skin and gills of kingfish, Seriola lalandi lalandi (Carangidae), collected from White Island (n = 32), Ranfurly Banks (n = 7), and Three Kings Islands (n = 7), is reported. Kingfish were host to two monogenean and four copepod ectoparasite species, Benedenia seriolae, Zeuxapta seriolae, Caligus lalandei, Caligus aesopus, Neobrachiella spp., and Lernanthropus spp., respectively. B. seriolae and C. lalandei infect the skin, whereas the remaining parasites were located on the gills. All parasites exhibited considerable variability in the prevalence and intensity of infection. A few kingfish were completely devoid of C. aesopus, Neobrachiella spp., and/or Lernanthropus spp., whereas others were infected by moderate numbers of these species. However, all kingfish were infected by B. seriolae and Z. seriolae. Therefore, it appears that acclimation of wild kingfish from the east coast of New Zealand's North Island into captivity will lead to the transfer of both B. seriolae and Z. seriolae, and that effective quarantine measures will be required to avoid introducing these parasites into broodstock systems. The site preferences of B. seriolae, Z. seriolae, and C. aesopus were also investigated. B. seriolae exhibited a preference for attachment on the lateral surfaces of the skin behind the dorsal fin, but forward of the anal fin. Z. seriolae displayed a preference for attachment on gill arches 2 and 3, particularly in gill filaments located in the upper regions of the buccal cavity. C. aesopus most commonly occurred on the gill arch.