Anisakids in marine fish from the coast of Chon Buri Province, Thailand.

A total of 1,600 specimens, consisting of 16 different species of marine fish, were dissected and examined for anisakid larvae and adults in visceral organs, abdominal cavity, and muscles. One species of adult-stage nematode was found in two of 16 species of marine fish studied, Johnius carouna and Dendrophysa russelli. No anisakid larvae (third-stage) was found in any of the 16 species of marine fish studied. Morphological study of the adult-stage nematode showed similar morphology to Anisakis simplex. We found that the nematode adult recovered from the marine fish differed from other anisakids in morphology, life cycle and locality of infection in the fish. The anisakid adults recovered were ovoviviparous or larviparous, but not oviparous as is seen in most other anisakids. The intensity and prevalence of nematode infection in Johnius carouna were 2.4 and 31.7%, respectively, and in Dendrophysa russelli 3.9 and 87.5%, respectively.