倪氏复口吸虫和湖北复口吸虫生活史的研究 Ⅰ.早期幼虫的实验生态

STUDIES ON THE LIFE HISTORIES OF DIPLOSTOMUM NIEDASHUI AND DIPLOSTOMUM HUPEHENSIS Ⅰ. THE EXPERIMENTAL BIONOMICS OF THE EARLY LARVAE

本文比较研究了倪氏复口吸虫(Diplostomum niedashui Pan & Wang)和湖北复口吸虫(Diplostomum hupehensis Pan & Wang)早期生活史的实验生态,包括温度、光照度对它们直接和间接的影响及某些数量的变化。

Water temperature shows a marked influence upon the incubation period of the eggs of the two species. Within the range of 20—35℃, the higher the temperature, the shorter is the incubation period. The curves of egg incubation rate of both species related to temperature are logistic. They can be expressed respectively by the following formulas:N_1+=1+e^(4.9347-0.1872t)/0.1095 and N_h=1+e^(5.2077-0.2117t)/0.1104 Where, N_n, N_h—rate of D. niedashui and D. hupehensis respectively; t—temperature.When the water temperature increases, the instantaneous hatching rate of both species increases according to the following equations: Y_n=0.0205t—0.3119 and Y_h=0.030t—0.5171.Where, Y_n, Y_h—instantaneous rate of each species; t—temperature.The miracidia of these allied species show a strong positive phototaxis and prefer swimming near the surface of water. The two cercariae shed from the gastropods 18—25 days after infection. They appear to be phototatic and suspending near the surface of water. The cercariae emerge from the snails discontinuously and in spurts at intervals. The emergence peak of the cercariae of both species appears from 8 to 10 am every day. Their emergence begin to reduce囔 by 2 pm and completely cease, after 6 pm.The populations of the two cercarie may also increase in logistic curves. They can be expressed respectively by the integral form of the logistic equations:N_n=209 362.8315/1+e^(4.3368-0.1308t) and N_h=448 376.6514/1+e^(5.8165-0.1495_t)Where, N_n, N_h—population of each species; t—day.