新疆虹鳟贝氏复口吸虫的空间分布

Spatial Distribution of Diplostomum baeri in Oncorhynchus mykiss in Xinjiang Province

为了解贝氏复口吸虫(Diplostomum baeri)在虹鳟(Oncorhynchus mykiss)眼部寄生的空间分布特点,2017年4次对新疆博尔塔拉蒙古自治州温泉县冷水鱼繁育基地的虹鳟进行采样调查,运用统计学方法对虹鳟眼睛寄生贝氏复口吸虫的空间分布特点进行分析。结果显示,在检查的61尾虹鳟中,检出贝氏复口吸虫9023只,单尾检出最多为388只。总感染率为100%,左右眼玻璃体的感染率为100%和96.7%,高于左右眼晶状体的感染率60.7%和42.6%。总平均感染强度为(147.9±11.6),左右眼玻璃体平均感染强度为(90.9±6.7)和(71.9±6.1),高于左右眼晶状体平均感染强度(7.4±1.9)和(7.0±2.1)。左眼和右眼的平均感染强度无统计学差异(P>0.05),晶状体和玻璃体的平均感染强度差异极显著(P<0.01)。贝氏复口吸虫在虹鳟不同部位的方均比(S^2/X)大于1,说明贝氏复口吸虫对该地虹鳟的寄生情况严重,在虹鳟的不同部位中均呈聚集性分布,更倾向于在玻璃体中寄生,存在寄生部位选择偏好性。

In the late 20 th century,rainbow trout(Oncorhynchus mykiss)were introduced to the cold water fish breeding station in Wenquan County,Bortala Mongolian Autonomous Prefecture,Xinjiang.Parasitization of rainbow trout by Diplostomum baeri has seriously impaired the development of rainbow trout aquaculture in Xinjiang Province.Spatial distribution of the parasites in the host can be used to analyze habitat characteristics of different parts of the host body and better understand the physicochemical requirements of the parasites.In this study the spatial distribution and infection status of D.baeri in the eyes of rainbow trout was investigated.The objectives were to generate data on the ecology of D.baeri and provide a reference to support disease prevention and healthy culturing of rainbow trout.In 2017,61 rainbow trout were randomly collected on four occasions from the cold water fish breeding station in Wenquan County.Total body length was recorded and the fish were placed into 3 groups according to length:L<18 cm,18 cm≤L<22 cm,and L>22 cm.The fish were sacrificed,the number of D.baeri in the lens and vitreous humor of both eyes were recorded,and the spatial distribution of D.baeri was analyzed statistically.The total number of D.baeri in the 61 trout was 9023,the maximum number detected in an individual fish was 388,and the mean infection intensity was(147.9±11.6).The mean infection intensity in left and right vitreous humor(90.9±6.7)and(71.9±6.1)was higher than in the left and right lens(7.4±1.9)and(7.0±2.1).The overall prevalence was 100%and the prevalence in the left and right vitreous humor(100%and 96.7%)was higher than in the left and right lens(60.7%and 42.6%).The difference in mean infection intensity between left and right eyes was not significant(P>0.05),but the difference in mean infection intensity between the lens and the vitreous humor was highly significant(P<0.01).One-way ANOVA indicated that lens infection intensity did not vary among body length groups(P>0.05),but the difference in vitreous humor infection intensity between the left eye and right eye was significant(P<0.05).The ratios of variance to mean infection intensity in different parts of the rainbow trout exceeded 1,indicating that D.baeri infection of rainbow trout is serious and the D.baeri population displays selectivity toward the vitreous humor.