A symmetric intraguild predation model for the invasive lionfish and native grouper

Abstract

Lionfish are top-level venomous predators native to the Indo-Pacific Ocean. Over the past decade, the species Pterois volitans and P. miles have become established throughout most of the western Atlantic Ocean, where they drastically impact coral reef communities. Overfishing of native species, such as grouper, who share their niche with lionfish may be the reason for the lionfish’s success; research has suggested that at high density, groupers can act as a lionfish biocontrol. To determine if competition or predation is the mechanism behind lionfish suppression, we construct a symmetric intraguild predation model of lionfish, grouper, and prey. Thus, we assume lionfish and grouper compete for prey in addition to consuming juveniles of the other species. Holling type I functional responses are used to represent fecundity and predation. We conduct an equilibrium stability analysis and bifurcation analysis of the general model, and find that the system is able to coexist in an equilibrium or sustainable oscillations. After estimating parameter ranges, simulations and a sensitivity analysis indicate the parameters most influential to lionfish growth rate. The implied control strategies are then tested by varying harvesting and predation rates.