Author: Jespersen and Tåning, 1919
Margrethia obtusirostra Jespersen and Taning, 1919
Status in World Register of Marine Species:
Accepted name: Margrethia obtusirostra Jespersen and Tåning, 1919 (updated 2009-06-25)
Diagnosis: body moderately elongate; mouth large; pseudobranch with 8-10 filaments; gill filaments longer than first ceratobranchial gillrakers; gillrakers on first arch 14-15 (16), 3 on hypobranchial; branchiostegal rays 16, 5 on epihyal. Dorsal finrays 15-16; pectoral finrays (14) 15-16; pelvic finrays 8 (9); anal finrays 23-25; anal fin origin slightly behind dorsal fin origin, anterior rays of both elongate; last dorsal and anal finrays split to base; dorsal adipose fin present. Pelvic fins slightly in. advance of dorsal fin origin. Swimbladder capacious. Vertebrae 33-34; Scales deciduous. Photophores (adult): absent on isthmus; OA and SO absent; ORB 1, OP 3, BR 11-12 (13), IV 12-13 (14) + 2, VAV 4; AC (12) 13 + 4 (3-5) = (16) 17, (12) 13 over anal fin. Colour: back dark, operculum silver; anterior rays of dorsal and anal fins dark. Size: to 83 mm SL.
Habitat: mesopelagic at 100-600 m, no diel vertical migrations. Food: crustaceans, small fishes. Reproduction: dioecious; spawning season in summer-autumn; post-larvae sink gradually with development; photo phore development complete by about 27 mm SL.
Distribution: subtropical-tropical in Atlantic, usually associated with continental and island slopes; absent in Mediterranean.
Eggs, larvae and young stages. Grey, 1964: 202, fig. 55.
Otoliths (sagitta). Kotthaus, 1967: 21, fig. 29-30.