舟山渔场鱼类异尖线虫感染现况及其理化耐受研究

A study of the infection and physicochemical characteristics of the marine fish infected by Anisakis L3 caught in Zhoushan Fishery

目的掌握舟山渔场鱼类异尖线虫感染情况，了解异尖线虫Ⅲ期幼虫（L3）理化生物学特性。方法对29种444尾海鱼进行实验室解剖，分离体内异尖线虫幼虫，镜下虫种鉴定；观察异尖线虫L3在不同介质、温度条件下生存耐受情况。结果共发现21种218尾海鱼有异尖科线虫L3感染，总感染率为49．10％（218／444），感染率高的鱼种有带鱼、鲐鱼、鱿鱼、白姑鱼和海鳗等，平均感染强度为15．28条／尾，218尾海鱼体内共检出异尖科线虫幼虫3332条，异尖线虫L3占99．46％（3314／3332），伪新地线虫L1只占0．54％（18／3332）。异尖线虫k对常用的调味品有较强的耐受力，高度白酒杀虫效果[存活（42．6±14．77）min]优于低度白酒[存活（127．1±63．40）min]；t=4．105，P〈0．05。低浓度复方甲苯咪唑（6．25g／L）杀虫效果[存活（28．10±4．95）h]优于高浓度[12．50、18．75g／L；存活（98．20±25．69）h、（113．60±26．35）h；F=45．198，P〈0．01]的，也优于其他药物[阿苯达唑、甲苯咪唑；分别存活（65．80±17．03）h、（94．20±39．77）h；F=17．393，P〈0．01]；异尖线虫L3在-20℃、-10℃时最长分别可存活9、12h，而在50℃、60℃时分别于〈11s、〈1s即死。结论舟山渔场鱼类异尖线虫幼虫感染率较高；异尖线虫幼虫耐低温而不耐高温。

Objective The aim of this research was to investigate the third phase Anisakis simplex larvae （ Anisakis L3 ） infection in marine fish caught in Zhoushan Fishery and to find out its physicochemieal and biological characteristics. Methods A total of 444 fish belonging to 29 species were dissected to isolate anisakis larvae which were then morphologically identified. The survival tolerance of Anisakis L3 were observed in various conditions, such as in different temperature and medium. Results A total of 218 fish from 21 species were infected by Anisakis simplex larvae, yielding an overall infection rate of 49. 10% （218/444）. Trichiurus haumela, pneumatophorus japonicus, miichthys miiuy, argyrosomus argentatus and anguilliformes had high infection rate and had an average infection intensity of 15.28 per fish. 3332 Anisakis larvae were detected in 218 fish, among which Anisakis L3 and Pseudoterranova larvae accounted for 99.46% （3314/3332） and 0.54% （18/3332）respectively. Anisakis L3 was highly resistant to common condiment. We found the liquor with high concentration of alcohol showed better insecticidal effect than that with low concentration of alcohol （ t = 4. 105, P 〈 O. 05 ） and low concentration mebendazole composite was not only more effective than high concentration mebendazole composite （ F = 45. 198, P 〈 0. 01 ） but also more effective than other drugs,such as albendazole and mebendazole. Anisakis L3 could live up to 9 h and 12 h at -20 ℃ , -10 ℃ respectively,however they were very sensitive to high temperature. It has been shown that they could only survive for less than 11 s and 1 s at 50 ℃ and 60 ℃ respectively. Conclusion The observed Anisakis L3 infection rate in the marine fish found in Zhoushan Fishery was very high. Anisakis L3 showed high resistance to low temperature but not to high temperature.