Early life ecology of the invasive lionfish (Pterois sp.)

The invasion of the western Atlantic by the Indo-Pacific lionfish (Pterois volitans/miles) represents a serious threat to the ecological stability of the region. The early life history of this predator remains poorly understood despite the important role of larval supply in reef fish population dynamics. In this study, we characterized spatiotemporal patterns in the distribution of larval lionfish collected in the western Caribbean, US Caribbean, and the Gulf of Mexico from a number of ichthyoplankton surveys conducted between 2009-2016. Using generalized additive models (GAMs) we assessed the relative influence of oceanographic and temporal variation on the distribution of lionfish larvae. We also examined otoliths to determine larval ages and to develop growth rate estimates. Ages ranged from 4 to 17 days while mean growth rates were 0.47 mm/day. Lionfish larvae were present at 7.4% of all stations sampled, and preliminary GAM results suggest that lionfish presence is associated with warmer surface waters and the lunar cycle. Year and location also strongly affected the larval distribution, likely a result of the ongoing expansion of the species during the sampling timeframe. Much of the variation in larval lionfish presence remained unexplained, and future studies can incorporate additional environmental factors that may enhance the predictive capabilities of the model. This study improves our understanding of the complexity of the lionfish larval stage and accentuates the need for further research into the early life history of this invasive species. The design and implementation of effective long-term lionfish control mechanisms will require a complete understanding of their life cycle.