Pterois volitans Linnaeus 1758
Pterois volitans (Red Lionfish) has an almond-shaped body, and a large head, one-third to one-half body length, with numerous head spines, and often with large tentacles above the eyes. Dorsal fin spines and rays of dorsal, anal, pelvic and pectoral fins are greatly elongated, making the fish look a little like an exploding firework. The caudal fin is rounded. Eleven species of Lionfish (Pterois are known, some very similar morphologically to P. volitans. Pterois miles, very similar to P. volitans, has also been introduced to the the Western Atlantic, and can be distinguished only by meristic counts, morphometrics, and fine morphological details, or molecular methods (Schultz 1986; Hamner et al. 2007; Freshwater er al. 2009; Florida Museum of Natural History 2017; Froese and Pauly 2017; USGS Nonindigenous Aquatic Species Program 2017). The dorsal fin of Pterois volitans has 13 spines and 9-12 (usually 11) soft rays. The anal fin has 3 spines, and 6-8 (usually 7) soft rays. (For P. miles, the usual numbers are 10 dorsal rays and 6 anal rays). Color patterns vary greatly with environment, but are basically zebra-striped in red and white. The soft dorsal, anal, and caudal fins are spotted. (Pectoral fins and fin spots are smaller in P. miles). The usual maximum size of P. volitans is ~380mm, but one specimen off Venezuela reached 457 mm (Schultz 1986; Ehemann 2017; Florida Museum of Natural History 2017; Froese and Pauly 2017; USGS Nonindigenous Aquatic Species Program 2017). Of 180 specimens of Western Atlantic Pterois examined at the molecular level by Hamner et al. 2004), 168 were identified as P. volitans, primarily a western Pacific species, 12 specimens as P. miles, whose range encompasses thee wstern tropical/subtropical Indian Ocean (Africa-Red Sea-Australia) (Hamner et al. 2007). For both species, intraspecific variation in color and morphology is greater than that between species (Schultz 1986; Lowe 2016). A dramatic case is the appearance and rapid spread of a an apparently distinct morphoology of the supraoptical tentacle in both species, both in Indo-Pacific and Atlantic populations. The supraoptical tentacle can either be a simple, unbranched tentacle, or have a highly branched 'peacock-feather' morphology. This polymorphism probably evolved before the divergence of the two species (Morris and Freshwater 2008). Recent genetic studies indicate that hybridization has been occurring between P. volitans and P. miles in the Atlanitc, and P. volitans, in its native Indo-Pacific, has undergone genetic exchange with the more localized species P. lunulata (Luna Lionfish) and P. russelli (Plaintail Turkeyfish) (Wilcox et al. 2018). These authors suggest that heterosis ('hybrid vigor') may have contributed to the invasiveness of inttoduced lionfishes.
Shortfin Turkeyfish, Indo-Pacific, also in aquarium trade, not yet found in wild (Lyons et al. 2017)
Zebra Turkeyfish, Indo-Pacific, also in aquarium trade, not yet found in wild (Lyons et al. 2017)
Pterois lunulata (Luna Lionfish), a Northwest Pacific native, is closely related to P. volitans (Red Lionfish), eastern Indo-Pacific, and P. russelli (Plaintail Turkeyfish), western Indo-Pacific (Wilcox et al. 2018).
Pterois miles (Devil-Firefish) can be distinguished from P. volitans only by meristic counts and molecular analyses (Schultz 1986; . It is native to the western Indo-Pacific, and has also been introduced to the Western Atlantic (Schultz 1986; Hamner et al. 1997). Where the species have been distinguished, P. miles has been much rarer than P. volitans (Hamner et al. 2004; Guzmán-Méndez et al. 2017).
Pterois russelli (Plaintail Turkeyfish), western Indo-Pacific, is closely related to P. volitans (Red Lionfish), eastern Indo-Pacific, and P. lunulata (Luna Lionfish), a Northwest Pacific native (Wilcox et al. 2018).