Scorpaena pepo, a New Species of Scorpionfish (Scorpaeniformes:Scorpaenidae) from Northeastern Taiwan, with a Review of S. onaria Jordan and Snyder

A new species of scorpionfish, Scorpaena pepo, is described on the basis of 4 specimens collected from off the northeastern coast of Taiwan in the northwestern Pacific Ocean, at a depth of ca. 200 m. The new species is closely related to S. onaria with which co-occurs in Taiwan. The 2 species are distinguished from other Indo-Pacific species of Scorpaena by the following combination of characters: the lateral surface of the lacrimal with a single spine, the posterior margin of the anterior lacrimal spine with an additional spine, the median interorbital ridge well developed, embedded cycloid scales covering the anteroventral surface of the body and the pectoral-fin base, a high body depth (36.4-45.1 % of SL), 43-48 longitudinal scale series, and the lateral line sloping steeply downward above the anterior 1/2 of the pectoral fin. The new species can be distinguished from S. onaria by having 16 pectoral-fin rays; 46-48 longitudinal scale series; the posterior margin of the maxilla extending well beyond a vertical through the posterior margin of the orbit; the highest portion of the median interorbital ridge greater in height than the interorbital ridges; the posterior end of the base of the 1st suborbital spine located below the eye, between the posterior margins of the pupil and orbit; the supraocular tentacle being shorter than the pupil diameter, its length 1.7-3.9% (mean 3.1%) of SL; and the head and body when fresh yellowish-orange, with numerous scattered small distinct black spots, except on ventral surface. Scorpaena pepo sp. nov. is a large species (attaining at least 245.1 mm SL), whereas S. onaria from the northwestern Pacific Ocean is relatively small (the largest specimen, 187.9 mm SL). Two geographical populations regarded as S. onaria are compared in detail with S. pepo.