Sex ratios of sea lampreys vary in response to the external environment. In order to analyze sex ratio and its dependence on local conditions, we need to develop models that reflect the relationship between sex ratio and resource availability. In this paper, we establish a link between individual sex and the availability of larval food resources. Then, we extend the object of study from individuals to populations and express the dynamics of the sex ratio as a differential equation. We introduce other factors affecting the sex ratio to refine the relationship between reproductive rates and sex ratios. To better model the growth of the lamprey population, we developed a Gompertz model that initially approximates the growth rate of the exponential function. And the introduction of the Allee effect provides a more comprehensive view of population growth.