Plainfin Midshipman

Porichthys notatus

The Plainfin Midshipman is a bottom-dwelling fish known for its unique bioluminescent photophores, which are arranged in a pattern reminiscent of naval uniforms. This species is found along the Pacific coast of North America, from Sitka, Alaska, to Magdalena Bay in southern Baja California. Divers may encounter it in shallow waters, particularly during its breeding season in the spring and early summer when it migrates to rocky intertidal zones. It typically inhabits sandy and muddy bottoms, ranging from just below the tide to depths of 366 meters. This fish can grow up to 38 cm in length and displays a color palette ranging from brownish to olive or iridescent purple on its dorsal side, with lighter shades on the sides and a yellowish or golden belly. The Plainfin Midshipman can be distinguished from similar species by the absence of bands on its caudal fin and its V-shaped branchiostegal photophore series. The diet of the Plainfin Midshipman includes crustaceans and fish, and it is primarily nocturnal, feeding at night and resting during the day. During the breeding season, males establish nests under rocks in intertidal zones, attracting females with their vocalizations. The male guards the eggs until they hatch and the juveniles leave the nest. The species is listed as Least Concern by the IUCN.