The construction of dams has significantly altered the hydrological conditions of rivers,and understanding the impact of fluctuating water environments on the incubation process of drifting fish eggs is crucial for fish reproduction and resource conservation.In this study,we quantified the impact of water oscillation on the incubation of Hypophthalmichthys molitrix eggs at different devel-opmental stages from the perspective of energy input,focusing on hatching rate,hatching duration,and larva malformation rate of silver carp eggs under different water oscillation intensities.On June 8 and 9 of 2022,indoor experiments were conducted to study the incubation condition of H.molitrix eggs at six developmental stages(cell cleavage,blastula,gastrula,neurula,organ differentiation peri-ods and larvae hatching out from the membrane)after being subjected to water oscillation of three in-tensities(600,1 200,1 800 r/min).The relationship between oscillation energy and hatching rate was then analyzed in terms of energy input to the fish eggs.Results show that the hatching rate of fish eggs decreased gradually,and the malformation rate of larvae increased with the increase of water os-cillation intensity or oscillation time.After oscillation of fish eggs at gastrula stage,the hatching rate of fish eggs decreased from more than 80％to less than 40％,and all the incubated larvae were de-formed,indicating that the most sensitive developmental stage to oscillation is gastrula stage.The in-cubation duration of most fertilized eggs at different developmental stages shortened after oscillation,and the incubation duration of fish eggs at organ differentiation stage and larvae breaking out from the membrane stage reduced by more than 30％after oscillation;when the mechanical energy input to a single fish egg at cleavage stage increased from 0 to 3.733x10-5 J,its hatching rate decreased by about 20％,and the malformation rate increased by more than 50％.The shortened incubation dura-tion of embryos after shaking is the result of environmental induction,which indirectly proves the plasticity and diversity of the hatching mechanism of semi-buoyant fish eggs.These findings provide a novel quantitative concept and method for assessing the impact of external stimuli on the develop-ment of semi-buoyant fish eggs.This has significant implications for the reproduction and resource conservation of fish species that produce semi-buoyant fish eggs.
关键词
鲢/漂流性卵/水体震荡/孵化率/畸形率/能量输入
Key words
Hypophthalmichthys molitrix/semi-buoyant fish eggs/water oscillation/hatching rate/malfor-mation rate/energy input
维普
万方数据