鲢指环虫病病原小鞘指环虫的存活时间

The life span of Dactylogyrus vaginulatus on Hypophthalmichthys molitrix

对小鞘指环虫纤毛幼虫和成虫的存活时间进行了研究。结果表明，该虫的纤毛幼虫在２２℃时一般可在曝气自来水中存活０．５～７７．７ｈ，在１２℃可达５．０～３１０．５ｈ；将成虫置于曝气自来水中，在４，１２，２０和２８℃的最长存活时间分别是３０５．７，２８３．６，１０１．２和７８．８ｈ。在１５～２４℃的水温条件下，该虫感染宿主后大约可存活１个月。

The life span of Dactylogyrus vaginulatus Chang et Niu, on gills of silver carp (Hypophthalmichthys molitrix), was studied. The larvae showed a wide spectrum of life span,which was considered to be important in the persistence of the parasite population.In case of failing to infect the host, some ciliated larvae might die within 1 hour after hatching(a h.)at 22 ℃.On the contrast,a few individuals lost reaction to provoking until only 77 7 hours a h..However,swimming individual were not observed 24 hours a h.and a half of larvae died 6 17 hours a h..When hatched at 12 ℃,larvae can survive and swim from 5 to 310 5 hours,and a half of larvae died 13 hours a h.. If removed from host and placed in aerated tap water, adult worms survived 305 7,283 6,101 2 and 78 8 hours a h. at 4,12,20 and 28 ℃ respectively. This parasite species had a life span of about one month on the host at temperature ranging from 15 to 24 ℃.