Reproductive life history characteristics of invasive red lionfish (Pterois volitans) in the northern Gulf of Mexico

Abstract

With invasive lionfish (Pterois spp.) increasing throughout the western North Atlantic Ocean and Gulf of Mexico (GOM), it is important to define life history characteristics to help understand the invasion and potential effects on receiving ecosystems. Although some aspects of reproduction are known elsewhere in the invaded range, little is known in the northern GOM [nGOM; Florida Keys (24.66°N) to south Texas (26.00°N)]. In the present study, gonadosomatic index (GSI) calculations were based on 4527 red lionfish Pterois volitans (Linnaeus, 1758) specimens (April 2012–March 2015). Male and female GSI peaked from May to October, corresponding with macroscopic gonadal assessments of reproductively active females. Histological examination of ovaries from 355 females found they were spawning capable during all months. Males (n = 211) were spawning capable in all months except March, the only month in which no actively spawning females were present. A significantly higher percentage of reproductively active females was found from May to December. Lionfish reached 50% maturity at a small size (166.6 mm TL, females; 145.2 mm TL, males). Mean relative batch fecundity (n = 71) was 92 eggs g–1 gonad-free body weight (GFBW) and was highest in August (207 eggs g–1 GFBW). The population spawning frequency was estimated to be every 2.5 d over 11 mo in the nGOM, corresponding to a maximum potential annual output of 2,332,490 eggs for an average sized (188.6 g) female. These reproductive characteristics are similar to invasive lionfish in tropical waters, although nGOM reproductive output appears higher. Our results represent the most comprehensive reproductive data on lionfish in their invaded range, and provide a baseline for management in the nGOM.