Poss’ Scorpionfish

Scorpaenopsis possi, commonly known as Poss's scorpionfish, is a venomous marine ray-finned fish classified under the Scorpaenidae family. This species is indigenous to the Indo-Pacific region and occasionally appears in the aquarium trade.

First documented in 2001 by distinguished American ichthyologists John E. Randall and William N. Eschmeyer, the type locality for this species is identified as Pitcairn Island. The species is named in tribute to American ichthyologist Stuart G. Poss.

Poss's scorpionfish is characterized by a large head, prominent eyes, and substantial pectoral fins, with a snout that is comparatively shorter than that of other scorpionfish. Notably, the fish may lack cirri above the eyes, or possess cirri that are significantly smaller in size relative to the eye. The dorsal fin is equipped with 12 spines and 9 soft rays, while the anal fin comprises 3 spines and 5 soft rays. A distinctive pretympanic spine, connected via a low ridge to the postocular spine, is unique to this species among Scorpaenopsis scorpionfish, though absent in juveniles. Due to its similarities with other species within the genus, identification in natural habitats can be challenging. Distinguished features include shorter and finer tassels on the lower jaw and large scales numbering 43-50 along the lateral line. Typically, a white patch beneath and in front of the eye, as well as a dark triangular patch below the eye, are visible. The maximum recorded standard length for this species is 19.4 cm (7.6 in).

Poss's scorpionfish is found across a broad Indo-Pacific range, extending from the Gulf of Suez along the eastern African coastline to 🇿🇦 South Africa, across the undefined islands, the 🇲🇻 Maldives and Laccadive Islands, islands of the eastern Andaman Sea, through 🇮🇩 Indonesia, and as far east as 🇵🇫 French Polynesia and north to 🇯🇵 Japan. Notably, it is absent from the southwestern Pacific and 🇫🇯 Fiji, where it is supplanted by Scorpaenopsis eschmeyeri. Habitating depths between 2 and 55 meters (6 ft 7 in and 180 ft 5 in), this species is typically associated with rocky or coral substrates.

Poss's scorpionfish is an ambush predator, lying in wait for smaller fish to stray within its reach. Typically solitary, this species is equipped with venomous spines in its fins, which serve as both a defense mechanism and a tool for predation.