Pagetopsis macropterus

Pagetopsis macropterus was first formally described in 1907, as Champsocephalus macropterus, by the Belgian-born British ichthyologist George Albert Boulenger, with the type locality given as near Cape Armitage, Ross Island, in Victoria Land.^[2] When Charles Tate Regan described the genus Pagetopsis this was its type species by monotypy.^[3] The specific name macropterus means "large-finned", an allusion to the large dorsal and pelvic fins, especially those of juveniles.^[4]

Pagetopsis macropterus has around 15 narrow dark bars, lighter at the center, on its grayish green body and dark stripes on its cheeks, but has a whitish ventral area. It grows to a maximum length of 33 cm (13 in) and lives at depths of 5 to 655 m (16 to 2,149 ft). The dorsal fins contain 12–15 spines and 27–32 soft rays, while the anal fin has 24–27 soft rays. It has a large mouth, with the maxilla reaching a level with the front third of the eye, and this has two rows of conical teeth in each jaw. The caudal fin is almost truncate but can be rounded.^[5]

Pagetopsis macropterus has a circum-Antarctic distribution on the continental shelf and the South Shetland Islands. It is a demersal fish which occurs at depths between 5 and 655 m (16 and 2,149 ft).^[1] The defense posture, noted in a study in 1969, is opening the mouth wide, expanding the corner of the mouth and the opercula, erecting the dorsal fin, holding the flared pectoral fins at a right angle towards the body, and bending the body into a semicircle. The same study suggested that this behavior was developed to deter predators such as the Weddell seal (which preys heavily on this species).^[5] Adults feed on fishes and krill. It is of no interest to commercial fisheries.^[1]