Abstract

The lionfish species complex (Pterois sp.) are invasive marine fishes that were introduced into the western Atlantic in the mid 1980s. The colonization of ecosystems by lionfish causes significant damage to fish communities and reef ecosystems. Management efforts to attenuate the invasion effects depend on the population dynamics and reproduction of the lionfish, but these parameters vary depending on the study location and environmental conditions. The objective of this study was to describe the lionfishes’ reproduction cycle in Martinique by studying annual variations in gonadosomatic index (GSI), gonad maturation, and concentrations of sex steroids, the latter of which have never been reported for this species complex. It was expected that lionfish could reproduce year-round, with no seasonality. Lionfish were sampled over 15 months, from May and July 2021 and from September 2021 to September 2022, on the west coast of Martinique. We captured 453 fish ranging from 7.5 to 42.3 cm. Histological observations indicated the presence of sexually mature males and females throughout the year, and we found that concentrations of sex steroids and GSI for both sexes were high enough to allow year-round sexual maturation. There were no seasonal differences in sex steroid concentrations, but GSI in females indicated that a greater reproductive effort may occur towards the end of spring. This study provides important insights into the population dynamics of lionfish in Martinique, which is essential for developing management strategies for this invasive species complex.