Common Name
Blackheaded Ridgehead
Year Described
Zugmayer, 1911
Identification
Dorsal Fin: III, 13
Anal Fin: I, 9-10
Pectoral Fin: 14-15
Pelvic Fin: I, 7
Caudal Fin: 9-10 branched, 2-4 procurrent rays
Lateral Scale Rows: 32-33
Gill Rakers: 31-33
Vertebrae: 27-28
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 beyond orbit. Eye relatively small. Preopercle with spines in the lower and upper margin and an unspined notch at the angle. 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 anterior to pectoral fin base. Three scales on cheek. Pyloric caeca number 8.
Color
Uniformly dark brown on the body and black on the head.
Size
Maximum size to 135.3mm SL
Habitat
Taken in open mesopelegic water and near the bottom from 0-3000m. Taken close to the surface at night.
Range
Known from the Gulf Stream region of the northwestern Atlantic from off the northeastern U.S. to Greenland and the northeastern 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.
Other Notes
According to Kotlyar (2009b), this and the southern circumpolar P. atlantica are the only Atlantic representative of the Poromitra cristiceps complex, which is most related to the P. crassiceps complex.