A multi-agent approach to couple the physiological and ecological level: What factors influence time to sex change?

A major challenge in ecological modeling of complex living system, is the integration of different models that describe the same phenomenon at different levels (physiological and ecological levels). The multi-agent paradigm provides an intuitive approach to model and simulate individual metabolism (Dynamic Energy Budget (DEB) model) and sexual behavior (Sex allocation model) and connect them to population-level proprieties. In this work, we model the energetic and sexual behavior of hermaphrodite species to determine the optimal size of sex change. For this purpose, we consider population dynamics and individuals evolutionary traits. Sex change size is seen as an emerging traits from both the set of intra-individual physiological traits, and inter-individual interactions. We develop an evolutionary individual-based model implementing these two models with a simple genetic algorithm to determine the optimal sex change size. The model description follows the ODD (Overview, Design concepts, Details) protocol, it is simulated with NetLogo platform and it is parametrized for Dusky grouper (Epinephelus marginatus). For this hermaphrodite species, both growth and maturation predicted by the model fit well with field observations.