Redescriptions of Pterois radiata and Pterois cincta (Scorpaenidae: Pteroinae) with notes on geographic morphological variations in P. radiata

Abstract

The lionfishes (Scorpaenidae: Pteroinae) Pterois radiata Cuvier in Cuvier and Valenciennes 1829 and Pterois cincta Ruppell 1838 are both redescribed as valid, although the latter has previously been regarded as a junior synonym of the former. Pterois (Pseudomonopterus) vittata Sauvage 1878 and Scorpaena barffi Curtiss 1944 are regarded as junior synonyms of P. radiata. Pterois radiata and P. cincta are easily distinguished from their congeners by usually having XII, 11 dorsal-fin rays and 16–17 pectoral-fin rays, in addition to five broad vertical bands on the side of the body and a single broad horizontal band on the side of the caudal peduncle. Pterois cincta can be distinguished from P. radiata by having extremely long fin rays [e.g., longest pelvic-fin soft ray length 48.2–71.9 (mean 60.0) % of standard length in P. cincta, 36.8–53.3 (44.7) % in P. radiata]; and relatively narrow main bands and broad additional (inserted) markings on the side of the body. Pterois radiata is widespread throughout the Indo-Pacific, ranging from the east coast of Africa eastward to French Polynesia, and from northwestern Australia northward to southern Japan; in contrast, P. cincta is restricted to the Red Sea, with the exception of several doubtful records. Intraspecific geographical variations in several morphological characters were recognized between Indian and Pacific Ocean P. radiata, the former having fewer scales on parts of the body, and occasionally absence of additional markings (between the second and third and fourth and fifth bands) on the sides of the body. Geographical variations in the number of pectoral-fin rays in Pacific Ocean populations of P. radiata are also documented and morphological changes with growth of the two species described in detail. A neotype is proposed for P. radiata.