Abundance and trophic ecology of the lionfish, Pterois volitans, in the Morrocoy National Park, Venezuela, Southern Caribbean Sea

摘要

The lionfish invasion, Pterois volitans, in the US Atlantic coast and the Caribbean Sea waters represents a threat to the functioning of native marine ecosystem. This species was first reported in the Venezuelan coast in 2010, and by 2013 was very common in reef areas. This study aims to evaluate the abundance and trophic ecology of the lionfish in the Morrocoy National Park, and compare its abundance with other native species. In 2013, visual censuses were carried out and lionfish specimens were collected in different habitats (reefs, seagrass and mangroves) at different depth levels (1-3, 6-9, 12-15 m). Results showed high variability in the abundance of the lionfish populations, with an average density of 46.30 (+/- 42.31 SD) fishes* ha-1 in reefs, while in seagrass and mangroves no specimens were recorded. The density in reefs of this species was no different between depth levels and was significantly higher than other native species surveyed (families Muraenidae and Serranidae). The diet of P. volitans was composed of fish and crustaceans, with a higher proportion of fishes in larger individuals. The most abundant fish families within the park, Labridae, Haemulidae and Gobiidae, were part of its diet. Given the generalist predator behavior of the lionfish, an increase in their populations could significantly affect the abundances of native fish families and the structure and functioning of the reef ecosystems.