Author(s)

Shuai Zhang, Yang Cao, Chang He, Yang Liu

Corresponding Author

Shuai Zhang

Abstract

This study investigates the impact of the sex ratio of seven-gill lampreys on the ecosystem and explores analysis based on the Logistic model. It is noted that variations in the sex ratio can affect the lampreys' reproductive capabilities, thereby influencing their role in the food chain. The sex ratio is influenced by a variety of external environmental and biological factors, which affect the internal sex ratio of lampreys through natural selection and adaptive behaviors. To quantify the relationship between the sex ratio and external environmental resources, this paper employs the Analytic Hierarchy Process (AHP) and Python software to assess the impact of different external factors on the sex ratio. Furthermore, by constructing an improved Lotka-Volterra model, this paper analyzes the dynamic relationship between predators and lampreys and its effect on the sex ratio. The model considers the impact of the sex ratio on the reproduction and mortality rates and establishes differential equations for male and female lampreys separately. Simulations reveal that adjustments in the sex ratio significantly affect the reproductive success and social structure of populations. Finally, using the Logistic model, this paper quantifies the impact of changes in the sex ratio on the overall population growth rate, indicating that a sex ratio close to 1:1 results in the highest population growth rate.

Keywords

Seven-gill lampreys; sex ratio; ecosystem; Logistic model; Lotka-Volterra model