齐齐哈尔地区麦穗鱼吸虫囊蚴感染情况及其种类鉴定

Prevalence of trematode metacercariae in Pseudorasbora parva and species identification in Qiqihaer area

为了解齐齐哈尔地区麦穗鱼体内吸虫囊蚴感染情况及种类,2021年6—11月每月初从嫩江流域齐齐哈尔段采集麦穗鱼,采用直接压片法检查吸虫囊蚴感染情况,人工消化法分离吸虫囊蚴,通过形态学特征对吸虫囊蚴进行初步分类。用不同类型的囊蚴分别饲喂6周龄昆明小鼠(50~80只囊蚴/鼠)和2周龄雏鸭(80~100只囊蚴/鸭)。分别于感染后第30、25天剖取小鼠和雏鸭肝胆管内的成虫,醋酸洋红染色后进行形态学鉴定。按月、季节统计麦穗鱼囊蚴感染率,分析麦穗鱼吸虫囊蚴感染情况。应用SPSS 26.0软件进行统计学分析,感染率的比较采用χ^(2)检验。结果显示,2021年6—11月共采集麦穗鱼600尾,371尾感染吸虫囊蚴,感染率为61.8%。共获得3种不同形态的吸虫囊蚴,根据囊蚴形态初步鉴定为华支睾吸虫、东方次睾吸虫和台湾次睾吸虫囊蚴,感染率分别为47.7%(286/600)、15.5%(93/600)和23.7%(142/600)。3种吸虫囊蚴感染小鼠和雏鸭后获得的吸虫成虫经形态学鉴定分别为华支睾吸虫、东方次睾吸虫、台湾次睾吸虫。6—11月麦穗鱼华支睾吸虫囊蚴感染率分别为26.0%(26/100)、31.0%(31/100)、52.0%(52/100)、66.0%(66/100)、63.0%(63/100)和48.0%(48/100),东方次睾吸虫囊蚴感染率分别为5.0%(5/100)、11.0%(11/100)、15.0%(15/100)、17.0%(17/100)、26.0%(26/100)和19.0%(19/100),台湾次睾吸虫囊蚴感染率分别为17.0%(17/100)、15.0%(15/100)、19.0%(19/100)、23.0%(23/100)、32.0%(32/100)和36.0%(36/100),3种囊蚴不同月份之间感染率差异均有统计学意义(χ^(2)=53.61、19.51、20.11,均P<0.05)。麦穗鱼华支睾吸虫、东方次睾吸虫和台湾次睾吸虫囊蚴夏、秋季感染率分别为36.3%(109/300)、59.0%(177/300),10.3%(31/300)、20.7%(62/300)和17.0%(51/300)、30.3%(91/300),3种囊蚴夏、秋季之间感染率差异均有统计学意义(χ^(2)=30.89、12.23、14.71,均P<0.05);夏、秋季3种囊蚴之间感染率差异均有统计学意义(χ^(2)=22.29、33.96,均P<0.05)。嫩江流域齐齐哈尔段麦穗鱼存在华支睾吸虫、东方次睾吸虫和台湾次睾吸虫囊蚴感染;3种吸虫囊蚴分别在9、10、11月份感染率最高。

To understand the prevalence of trematode metacercariae and their species in Pseudorasbora parva from Nenjiang River around Qiqihaer City.P.parvas were collected from Nenjiang River around Qiqihaer City at the begining of each month from June to November in 2021.The prevalence of metacercaria of trematodes was examined by direct tablet,and the metacercaria of trematodes were isolated and purified by digestion.The metacercaria of trematodes were preliminarily classified by morphology.Mice(50-80 metacercaria/mouse)aged 6 weeks and ducks(80-100 metacercaria/duck)aged 2 weeks were fed with different types of metacercaria.The mice and ducks were dissected on the 30th and 25th day after infection,and the adult worms in the hepatobiliary duct were collected and stained with magenta acetate for morphological identification.The prevalence of metacercaria infection in P.parva was analyzed by month and season.SPSS 26.0 software was used for statistical analysis,and the preva-lence was compared byχ^(2)test.From June to November 2021,a total of 600 P.parva were collected,and 371were infected with metacercaria,with an prevalence of 61.8%.A total of three different type metacercaria were obtained.According to the morphology,it was preliminarily identified as C.sinensis,M.orientalis,M.taiwanensis metacercaria,the prevalences were 47.7%(286/600),15.5%(93/600)and 23.7%(142/600),respectively.The adult worms obtained from mice and ducks infected with the three types of metacercaria of trematodes were identified by morphology as C.sinensis,M.orientalis and M.taiwanensis.From June to November,the prevalences of C.sinensis metacercaria in P.parva were 26.0%(26/100),31.0%(31/100),52.0%(52/100),66.0%(66/100),63.0%(63/100)and48.0%(48/100),respectively.The prevalences of M.orientalis metacercaria were 5.0%(5/100),11.0%(11/100),15.0%(15/100),17.0%(17/100),26.0%(26/100)and 19.0%(19/100),respectively.The prevalences of M.taiwanensis metacercaria were 17.0%(17/100),15.0%(15/100)19.0%(19/100),23.0%(23/100),32.0%(32/100)and 36.0%(36/100),the prevalences of the three metacercaria types in different months have statistical significance(χ~2=53.61,19.51,20.11;P<0.05).The prevalences of metacercaria of C.sinensis,M.orientalis and M.taiwanensis in summer and autumn were 36.3%(109/300),59.0%(177/300);10.3%(31/300),20.7%(62/300);17.0%(51/300)and 30.3%(91/300),respectively,there were statistically significant differences in the prevalence of the three metacercaria in summer and autumn(χ~2=30.89,12.23,14.71;all P<0.05).The difference of prevalences between three kinds of metacercaria in summer and autumn was statistically significant(χ~2=22.29,33.96;all P<0.05).P.parvas were infected with metacercaria of C.sinensis,M.orientalis,M.taiwanensis in the Qiqihar section of the Nenjiang River.The prevalence of three types of metacercaria were the highest in September,October and November respectively.