Phenacoscorpius trispinis, a new species of scorpionfish (Teleostei: Scorpaenidae) from Sagami Bay, Japan

Abstract Phenacoscorpius trispinis (Teleostei: Scorpaenidae), a new species of scorpionfish is described from Sagami Bay, Japan. The new species is characterized by the following combination of characteristics: pectoral-fin rays 16 or 17, middle rays branched; pored lateral-line scales 4; upper gill rakers 6, lower gill rakers 14 (10 and 4 on ceratobranchial and hypobranchial, respectively), total gill rakers 20; no slit behind last gill arch; palatine teeth absent; anterodorsal and lateral lacrimal spines present; second preopercular spine smaller than third or fourth spines; nuchal and parietal spines distinct; head length 45.2% of SL (standard length); body depth 38.1% of SL; head width 17.2% of SL; snout length 11.2% of SL; maxillary depth 7.6% of SL; postorbital length 21.2% of SL; first dorsal-fin spine length 6.8% of SL; second dorsal-fin spine length 13.6% of SL; pelvic-fin spine length 19.9% of SL; longest pelvic-fin ray 23.2% of SL; longest pectoral-fin ray 39.0% of SL; caudal-fin length 25.3% of SL; caudal-peduncle length 17.2% of SL. A molecular genetic analysis based on the mitochondrial marker Cytochrome c oxidase subunit I showed that the new species formed a clade distinct from congeneric species. New standard Japanese names are proposed for both the genus Phenacoscorpius and the new species.