Abstract:

Objective To understand the infection status and species of the larvae of Anisakis nematodes in sea fishes along Fujian coast. Methods The samples of marine fishes were randomly collected from three major fisheries along Fujian coast (Eastern, Middle and Southern) during January 2016 to December 2018. The fish species were identified and the Anisakis larvae were isolated from the visceral and muscle tissues of the infected fishes. The species of infected Anisakis spp. was examined and identified under dissecting microscope. The data of fish species, Anisakis species and infection rate were collected and analyzed. Results A total of 810 marine fishes classified as 32 species were examined, and the overall infection rate of Anisakis nematodes was 34.2% with average 11.2 worms in each infected fish. The fish species with highest infection rates of the nematode were Trichiurus lepturus (85.6%, 95/111), Scomberomorus niphonius (63.5%, 47/74), Ditrema temmincki Bleeker (36.7%, 67/162) and Plectorhynchus nitens (36.7%, 18/49), with average 23.1, 7.6, 4.5 and 4.2 larvae for each infected fish, respectively. The distribution of Anisakis larvae differed in different fish species, commonly seen in the mesenteric and intestinal wall, body cavity and gastric wall of those infected fishes followed by livers, pancreas and genitals, rarely seen in the muscle. Total four species of Anisakis nematodes were identified in the larvae collected from the fishes: Anisakis type Ⅰ, Anisakis type Ⅱ, Hysterothylacium amoyense and other Hysterothylacium. Conclusion The infection rate of Anisakis larvae in sea fishes along Fujian coast is high, and more prevention and control measures should be adopted and strengthened.

Key words: Anisakis spp., Infection rate, Species identification, Fujian Province