A New Lionfish of the Genus Dendrochirus (Scorpaenidae: Pteroinae) from the Tuamotu Archipelago, South Pacific Ocean

Abstract

Dendrochirus tuamotuensis sp. nov. (Scorpaenidae: Pteroinae) is described on the basis of a single specimen collected off Makemo Atoll, Tuamotu Archipelago, South Pacific Ocean. The new species is uniquely characterized by having bi- lobed pectoral fins, those of its all congeners being rounded. The new species is similar to a Hawaiian endemic congener, Dendrochirus barberi (Steindachner, 1900), in having nine dorsal-fin soſt rays, five anal-fin soſt rays, relatively high counts (more than 18) of pectoral-fin rays, fewer than two tentacles on the snout tip, and no large, ocellated spot on the soſt-rayed portion of the dorsal fin. However, the new species is clearly distinguished from D. barberi by having more pectoral-fin rays (19 in the former vs usually 18 in the latter), higher counts of spinous points on the suborbital ridge (14–16 vs 1–9) and pterotic spine (8 vs 1–5), a slightly shallower, narrower body [body depth and width 35.4% of SL and 18.6% of SL, respec- tively, vs 34.0–43.9 (mean 39.2)% of SL and 19.7–26.4 (22.7)% of SL], a slightly shorter, narrower head [head length and width, 37.6% of SL and 12.9% of SL, respectively, vs 40.3–45.7 (42.9)% of SL and 13.8–17.2 (15.4)% of SL], slightly smaller orbit diameter [12.9% of SL vs 13.1–16.0 (14.2)% of SL], and a slightly shorter postorbital length [15.3% of SL vs 16.4–20.6 (18.5)% of SL].