The Impact of Sex Ratio Adjustment on Population Dynamics and Ecosystems in Marine Sea Lampreys

As climate change leads to more frequent intense environmental changes in aquatic ecosystems, understanding how marine species adapt under changing conditions is increasingly important. This study investigated the survival strategies of sea lampreys under varying temperatures and food availability. A logistic model was developed based on changes in sex structure to examine if sex ratio adjustment could act as an adaptive mechanism under different environments. A food chain Lotka-Volterra model then investigated the impacts of sex ratio changes in sea lampreys on ecosystem dynamics. Resource utilization ratio varied with sex ratios, maximizing at 37.16% and minimizing at 1.43. Excessive sex ratio changes could destabilize the ecosystem. A population dynamics model compared the effects of initial fixation and variable sex ratios on population size. Sea lampreys showed the highest predation rate at a sex ratio of 1.43, best suited for population growth, averaging 35.31%, much higher than 4.68% under initial fixation. Findings provide insights into how species use plasticity to adapt to global change and may inform sea lamprey control strategies.