Common Name
Antarctic Ridgehead
Year Described
Norman, 1929
Identification
Dorsal Fin: III, 14-16
Anal Fin: I, 10-11
Pectoral Fin: 13-15
Pelvic Fin: I, 7
Caudal Fin: 9-10 branched, 2-4 procurrent rays
Lateral Scale Rows: 29-33
Gill Rakers: 29-32
Vertebrae: 28-30
Head with heavy bony ridging and pitting. A conspicuous anterior spine in front of eye and bony crest present on top of head (characteristic of Poromitra). Rear margin of mouth extends to rear orbit or just short of it. Eye relatively small. Preopercle with spines in the lower and upper margin and an unspined notch at the angle (spined in largest specimens). Anterior preopercular margin with ridges at an acute angle. Opercle with serrated upper margin. Anal fin origin under dorsal ray 5 or 6. Pectoral fin extends to rear dorsal fin base. Pelvic fin origin directly under or behind pectoral fin base. Three scales on cheek. Pyloric caeca number 7-8.
Color
Uniformly dark brown with a darker head.
Size
Maximum size to 116mm SL.
Habitat
Mesopelagic from 0-3350m
Range
Found throughout the Southern Hemisphere and Antarctic waters. Known from the Southern Ocean north to the coast of Argetina and north of the Scotia Arc in the ocean South Atlantic.
References
Kotlyar, A. N. 2009a. Revision of the genus Poromitra (Melamphaidae): Part 3. Species of group P. cristiceps: P. cristiceps, P. nigrofulva, P. frontosa, P. nigriceps. Journal of Ichthyology v. 49 (no. 6): 421-434.
Kotlyar, A. N. 2009b. Revision of the genus Poromitra (Melamphaidae). Part 4. Species of P. cristiceps group: P. atlantica, P. oscitans and P. agafonovae Kotlyar, species nova. Journal of Ichthyology v. 49 (no. 8): 563-574.
Other Notes
According to Kotlyar (2009b), this and P. nigriceps are the only Atlantic representative of the Poromitra cristiceps complex, which is most related to the P. crassiceps complex. Poromitra nigriceps is a tropical and subtropical species and this is a southern hemisphere endemic.