The life history characteristics of invasive lionfish ( Pterois volitans and P. miles ) in Bermuda

Since the first reported sighting of Indo-Pacific lionfish ( Pterois volitans and P. miles ) in the Atlantic Ocean over 30 years ago, growing evidence suggests they may have a marked negative impact upon ecosystems and demersal communities. While lionfish populations expanded rapidly in most locations following their initial establishment, the population in Bermuda, the first location outside of the United States to be invaded, appears to be growing at a slower pace. This study investigated the life history characteristics of the invasive lionfish population in Bermuda to help understand population dynamics and thus potential impacts on Bermuda’s coral reef ecosystem. Annual growth rings in lionfish otoliths were counted to describe population structure and establish size-at-age, which was then utilized to estimate growth parameters using von Bertalanffy models. Macroscopic and histological staging of ovaries, calculations of gonadosomatic and hepatosomatic indices, and enumerations of mature oocytes were used to describe reproductive seasonality and capacity. Our findings show that lionfish in Bermuda appear to grow faster and attain larger mean sizes than they do in their native range or elsewhere in the invaded range. Lionfish in Bermuda, however, appear to reach maturity at larger sizes and have a shorter spawning season, a likely result of the cool winter seawater temperatures in the region. It is possible that the combination of these life history characteristics could mitigate or delay the ecological impact that invasive lionfish may have on this marine ecosystem.