基于Lotka-Volterra种群动态模型的水生动物性别比例变化研究
Study on the Change of Sex Ratio of Aquatic Animals Based on the Lotka-Volterra Population Dynamics Model

水生动物的性别比例会受遗传因素与外界环境、激素的影响，其具有适应性别比例变异的特征，且性别比例变化对种群自身及其他物种都有一定影响。主要从物种间的内部机制与外部资源环境因素两方面论述。通过已知性别决定因素，构造性别比例变化与资源可用性相关函数，考虑性别比例变化与生存环境面积的影响，建立基于Lotka-Volterra的系统动态模型。本文以海七鳃鳗为例，运用模型进行研究，研究得到其在性别比例变化下种群数量变化曲线随时间呈周期性，且猎食者的数量波动相比于猎物的数量呈现约四分之一个周期的滞后效应。
The sex ratio of aquatic animals will be affected by genetic factors, external environment and hormones, and it has the characteristics of adapting to the variation of sex ratio, and the change of sex ratio has a certain impact on the population itself and other species. This paper mainly discusses the internal mechanism between species and the external resource and environmental factors. Based on the known sex determinants, the correlation function between the change of sex ratio and resource availability is constructed, and the influence of the change of sex ratio and the area of living environment is considered, and the system dynamic model based on Lotka-Volterra is established. In this paper, the lamprey is taken as an example and a model to study. The model was used to study the population size curve with time under the change of sex ratio, and the number of predators fluctuated compared with the number of prey. There is a lag effect of about a quarter of a cycle.