Notes On The Larvae Species Of Anisakidae (Nematoda: Ascaridida) From Marine Fishes From Yellow Sea

The larvae species of anisakid nematodes from marine fishes in Yellow Sea were investigated during May 2005 to October 2006. 950 fishes belonging to 94 species, 55 genera and 38 families were examined for nematodes. Nematode larvae were identified by Light Microscopy (LM) and Scanning Electron Microscopy (SEM) observation. The main results are as follows:1. Six types of anisakid nematodes belonging to 3 genera were determined. They are Anisakis Type I; Hysterothylacium Type I, Type II, Type III, Type IV; and Raphidascaris or Raphidascaroides Type I.2. All larvae types were measured, described and illustrated. SEM observations of all larvae types of anisakid nematodes were made at first time, the results will provide the new characters for the identification and taxonomy of anisakid larvae.3.According to morphological character,measure data,parasitical host and the adults , three larvae are speculated to the species,Anisakis Type I larvae is Anisakis simplex complex ; Hysterothylacium Type II is Hysterothylacium fabri, Hysterothylacium Type IV Hysterothylacium aduncum。4. In the present study, Hysterothylacium Type III fourth stage larvae are firstly reported. many new hosts were recorded including 6 new hosts for Anisakis Type I larvae; 4 new hosts for Hysterothylacium Type I; 9 new hosts for Hysterothylacium Type II; 37 new hosts for Hysterothylacium Type III third stage larvae, 20 new hosts for Hysterothylacium Type III fourth stage larvae; 14 new hosts for Hysterothylacium Type IV third stage larvae; 7 new hosts for Raphidascaris or Raphidascaroides Type I.5. In this study, 94.6% (88/94) species of marine fishes from Yellow Sea are infected with anisakid nematodes. There are no anisakid nematodes in Dasyatis akajei,Pteroplatea japonica,Spheroides rubripes,Psenopsis anomala,Cynoglossus semilaevis。Most of fishe species are infected with 1-2 types of larvae anisakid nematodes although all six types of larvae nematodes were found in two species of marine fishes (Argyrosomus argentatus and Lepidotrigla microptera).6. Hysterothylacium Type III third stage larvae(91%), Anisakis Type I (70%), and Hysterothylacium Type IV third stage larvae (62%) are heavy infected in marine fishes from Yellow Sea. Among them, Hysterothylacium Type III third stage larvae is core species with highest infective rate.