Redescription of the poorly known Japanese scorpionfish Scorpaena brevispina (Perciformes: Scorpaenidae).

This study presents a redescription of the Japanese Shortspined Scorpionfish, Scorpaena brevispina, a previously described species based on limited morphological data from the holotype. The redescription incorporates an expanded dataset from 14 collected specimens from the Sagami Sea, Japan, including additional morphological characters, meristic counts, and morphometric analyses, providing a more comprehensive understanding of the species. Morphological comparisons with closely related taxa support the validity of S. brevispina, refining its diagnostic characters: 4446 scale rows in longitudinal series; 23 pored lateral-line scales; 57 (usually 6) scale rows above lateral line, 1114 (12 or 13) below, 6 or 7 between sixth dorsal-fin spine base and lateral line, and 57 (6) between last dorsal-fin spine base and lateral line; 35 (4) pre-dorsal scale rows; 17 or 18 (18) gill rakers; anterior surface of preocular spine with three vertical or slightly oblique ridges in large specimens; anterior lacrimal spine with 1 or 2 additional spinous point, directed anteroventrally; lateral lacrimal spine present, with 1 spinous point; body relatively deep [depth 34.942.0% of standard length (SL)]; third to fifth dorsal-fin spine lengths 15.920.3% of SL, 16.020.1% of SL, and 16.120.2% of SL, respectively. The study also provides ecological observations, further contributing to knowledge of the species natural history and biogeography.