Magnisudis prionosa

Magnisudis prionosa (Rofen, 1963)

Paralepis atlantica prionosa Rofen, 1963:1 (type locality:Antarctic, from a whale stomach).

Magnisudis prionosa (Rofen, 1963): Post, 1987:95. Duhamel et al., 2005:152. Stewart, 2015:591.

Specimen examined. MNHN 2000-0453 (ca. 562 mm SL; nape broken), “Tangaroa”, Halipro 2 cruise, station bt41,, 25°46’58.8”S, 167°10’58.8”E, New Caledonia, Coral Sea, Pacific, 1317–1383 m, 14 Nov. 1996.

Description. Dorsal-fin rays 11; pectoral-fin rays 20 (19 on left side); anal-fin ryas 22; pelvic-fin rays 9. Lateral-line scales: prepelvic 31; predorsal 32 (33); preanal 48 (47); total 63 (61); transverse scale rows below LL ca. 22–25. Vertebrae: predorsal 33; prepelvic 34; preanal 48; total 70; numbers of prehaemal and caudal vertebrae not available.

Bode moderately slender, slightly compressed. Head robust, its length about 4.4 in SL. Interorbital space flat, with a low straight ridge on each side extending from near tip of snout to dorsal surface of skull. Snout moderately long, stout, bluntly pointed at tip. Eye large, 2.8 in snout length. Two nostrils closed together, both clearly before level of posterior end of maxilla by about half eye diameter. Mouth gape extending to below nostrils. Posterior tip of maxilla about half eye diameter in front of eye. Caudal peduncle longer than eye diameter.

Pectoral fin moderately long, not especially filamentous. DFO and VFO clearly behind middle of the fish. VFO slightly behind DFO, below anterior third of dorsal-fin base. Anus well behind posterior tip of suppressed dorsal and pelvic fins. Dorsal adipose fin with short base, much smaller than eye diameter, gap between adipose fin and base of caudal fin about three times adipose-fin base.

Scales small, cycloid, scale rows between lateral line and ventral margin estimated ca. 22–25. Lateral-line scales enlarged, slightly higher than wide. Lateral-line runs to near the end of anal-fin base.

No trace of gill rakers and teeth on jaws and palatines. Teeth on pharyngeal plates tiny forming two large patches.

Body more or less uniformly blueish black, paler on upper and lower margins of lateral line; darker on ventral surface and fins. Adipose fin with pale base. Anus white. Peritoneal membranes black.

Remarks. We identified the specimen as M. prionosa from the distribution range (Southern Hemisphere) and 70 total vertebrae, based on Post (1987: 89; in Key). The specimen is in quite good condition, except where the nape region was badly damaged. It is a female with free eggs in ovaries; probably in the final stage of spawning.