Identification Of The Nematode Parasites Infecting In The Commercially Important Marine Fishes From The Yellow Sea

Marine fishes represent the important components of the diet in the coastal areas of China. In order to evaluate the species diversity, prevalence and intensity of nematode parasites in the commercially important marine fishes in China, 20 fish species(in total, 129 samples) collected from the Yellow Sea, China(off Shidao, Shandong Province), were surveyed in the present study. Morphological methods including light and scanning electron microscopy, and molecular techniques by sequencing and analysing the internal transcribed spacer(ITS) of the ribosomal DNA were utilized for exact differentiation and identification of the obtained adult and larval nematodes. The results of detailed studies of these parasites are presented below:1) Neoascarophis shandongensis sp. nov.(Spirurida: Cystidicolidae) collected from Conger myriaster(Brevoort)(Anguilliformes: Congridae) was described.2) 4 nematode species of Ascaridida were identified and described, including: i) Adults of Hysterothylacium aduncum(Rudolphi, 1802) collected from Gadus macrocephalus Tilesius(Gadiformes: Gadidae); Third-stage larvae of H. aduncum collected from G. macrocephalus Tilesius, Priacanthus tayenus Richardson(Perciformes: Priacanthidae), Sebastiscus marmoratus(Cuvier)(Scorpaeniformes: Sebastidae), Pseudopleuronectes yokohamae(Günther)(Pleuronectiformes: Pleuronectidae), Nibea albiflora(Richardson)(Perciformes: Sciaenidae), Coilia nasus Temminck & Schlegel(Clupeiformes: Engraulidae), Okamejei kenojei(Müller & Henle)(Rajiformes: Rajidae), Cynoglossus lachneri Menon(Pleuronectiformes: Cynoglossidae), Hexagrammos otakii Jordan & Starks(Scorpaeniformes: Hexagrammidae), Inimicus japonicus(Cuvier)(Scorpaeniformes: Synanceiidae), Pholis nebulosa(Temminck & Schlegel)(Perciformes: Pholidae); Fourth-stage larvae of H. aduncum collected from G. macrocephalus Tilesius, Lophius litulon(Jordan)(Lophiiformes: Lophiidae), S. marmoratus(Cuvier), O. kenojei(Müller & Henle), H. otakii(Jordan & Starks) and I. japonicus(Cuvier). ii) Third-stage larvae of Hysterothylacium liparis Li, Xu & Zhang, 2007 collected from G. macrocephalus Tilesius, L. litulon(Jordan), S. marmoratus(Cuvier), P. yokohamae(Günther), N. albiflora(Richardson), Collichthys lucidus(Richardson)(Perciformes: Sciaenidae), C. nasus Temminck & Schlegel, Pseudopleuronectes herzensteini(Jordan & Snyder)(Pleuronectiformes: Pleuronectidae), O. kenojei(Müller & Henle), C. lachneri Menon, H. otakii Jordan & Starks, Bathyraja smirnovi(Soldatov & Pavlenko)(Rajiformes: Arhynchobatidae), Erisphex pottii(Steindachner)(Scorpaeniformes: Aploactinidae), Paralichthys olivaceus(Temminck & Schlegel)(Pleuronectiformes: Paralichthyidae), P. nebulosa(Temminck & Schlegel); Fourth-stage larvae of H. liparis collected from G. macrocephalus Tilesius, L. litulon(Jordan), O. hollandi(Jordan & Richardson)(Rajiformes: Rajidae), C. lucidus(Richardson), C. nasus Temminck & Schlegel, H. otakii Jordan & Starks. iii) Third-stage larvae of Hysterothylacium fabri(Rudolphi, 1819) collected from G. macrocephalus Tilesius. iv) Third-stage larvae of Anisakis pegreffii Campana-Rouget & Biocca, 1955 collected from G. macrocephalus Tilesius, L. litulon(Jordan), P. yokohamae(Günther), C. nasus Temminck & Schlegel, O. kenojei(Müller & Henle), H. otakii Jordan & Starks, Sillago sihama(Forssk?l)(Perciformes: Sillaginidae), I. japonicus(Cuvier), P. nebulosa(Temminck & Schlegel).Furthermore, the prevalence and intensity of nematode parasites in the commercially important marine fishes were also analysed. The present investigation adds new data to the study of helminth parasites of marine fishes from the Chinese waters.