Metazoan parasites of the snapper,Pagrus auratus(Bloch & Schneider, 1801), in New Zealand. 1. Prevalence and abundance

Abstract

Abstract The prevalence and abundance of nine species of ectoparasites and seven species of endoparasites found on the snapper, Pagrus auratus, collected from the Hauraki Gulf, New Zealand, is reported. The metazoan fauna of Pagrus auratus in this study was dominated by a single highly prevalent and abundant species, Diphthero‐stomum sp., which accounted for 84% of all the parasites collected during this study and occurred in all snapper older than 2 years. Several other moderately abundant species were highly prevalent, occurring in 50–60% of the snapper sampled. These included Lamellodiscus pagrosomi, Bivagina pagrosomi, Cucullanus sp., and Unicolax chryso‐phryenus. The remainder of the parasite fauna comprised rare species of limited prevalence and low abundance, accounting for 7.7% of the individuals collected. These included Choricotyle australiensis, phyllobothriid and dasyrhynchid plerocercoids, Proctoeces sp., Philometra lateo‐labracis, and Anisakis sp. Correspondence analysis indicated that different age classes of the host snapper had distinctive parasitic faunas, with 0+ snapper characterised by low abundance and prevalence of all species except C. australiensis and the phyllobothriid plerocercoid. A progressive increase in many of the species of parasites constituted the major faunistic differences between 1+, 2+, and 3+ snapper. The implications for fisheries and aquaculture of the composition of the metazoan parasitic fauna of P. auratus are discussed.