The Indo-Pacific scorpionfish genus Scorpaenopsis includes around two dozen recognized species (24 recognized by Randall and Eschmeyer 2001 and several additional species described more recently). Scorpaenopsis obtusa (Shortsnout Scorpionfish) was formally recognized as a distinct species only in 2001 based on three specimens, two from the Philippines and one from Papua New Guinea. Four additional specimens have been subsequently identified that were collected in Japan and Western Australia, as well as Papua New Guinea. Collection data indicate capture depths ranging from 0 to 50 m. Scorpanopsis obtusa is presumed to be a demersal fish, i.e., living on or near the seabottom. This is the smallest “humpback” species in the genus. Known specimens have ranged in size from from 36.5 to 79
mm standard length (i.e., excluding the tail) (Motomura and Shinohara 2005). Motomura and Shinohara discuss technical characters for discriminating this species from related species, notably the very similar S. gibbosa. These authors note that S. obtusa is currently known from the eastern Indian and western Pacific Ocean, whereas S. gibbosa is distributed in the western Indian Ocean, suggesting that a vicariance event may be related to speciation within Scorpaenopsis.