A Systematic Study of the Nematodes Parasitic in New Zealand Marine Fish, with an Account of the Life History and Culture of Stomachus marinus (Linn., 1767)

Abstract

Three hundred and forty inshore fish have been examined for adult and larval parasitic nematodes. Nematodes were present in 44 species of 42 genera. A further 12 species of 11 genera were examined and found to be negative. Where species were found infested with nematodes the overall infestation was 76%. From the above fish 22 species of nematodes ore recorded. Three of the five nematode orders are represented, O. Ascaroidea, O. Filarioidea and O. Trichinelloidea. The O. Filarioidea with 14 species is by far the best represented. Of the 22 species described, all but three species are new to New Zealand. Of these three species two are endemic, Hedruris spinigera and Cucullanus antipodeus. Nineteen new hosts are recorded for the larva of the cosmopolitan species, Stomachus marinus, and this worm is recorded for the first time from an invertebrate host, the common New Zealand squid, Notododarus sloanii. The following five new species are fully described and figured: Ascarophis physiculi, A. coelorhynchi, A. usacarangi, Cucullanellus campbelli and C. pagri. Positive indentification of a further nine species (three of Contracaecum, four of Cucullanus and two of Capillaria) is withheld owing to difficulties in obtaining literature, but it is highly probable that the nine species will prove to be endemic. Larval cultures of S. marinus under a wide range of conditions led to a successful last ecdysis which definitely confirmed the previously hypothetical correlation of the larva in the fish with the adult in the porpoise. Evidence is presented indicating two rather than one intermediate host in the life cycle of S. marinus. Munida is suggested as an invertebrate intermediate host preceding the known vertebrate host - teleost fish.