Author: Tåning, 1928
Diaphus brachycephalus Tåning, 1928
Status in World Register of Marine Species:
Accepted name: Diaphus brachycephalus Tåning, 1928 (updated 2009-06-25)
Diagnosis: dorsal finrays 13 (rarely 12 or 14); anal finrays 13 (rarely 12 or 14); pectoral finrays 11 (10-12). Gillrakers 6 (5-7) + 1 + 12-13 (11-14), total 19-20 (18-22, rarely 17). AO 5 (rarely 4 or 6) + 4 (rarely 3 or 5), total 9 (rarely 8 or 10). Adult males with anterior region of Vn expanded. Size: to 57 mm, but specimens from western Atlantic, south of 17° S, about 36 mm.
Habitat: high-oceanic, mesopelagic: day at 175-550 m; night from near surface to 225 m (maximum abundance at 100 m); specimens from north of 30° N in eastern Atlantic below 600 m at night; near Bermuda: night at 101-250 m (maximum abundance at 151-200 m). Large males (>40 mm) may be partial or non-migrants (Hawaii). Food: no data. Reproduction: generally sexually mature from about 38 mm, but specimens from western Atlantic south of 17° S sexually mature from 27 mm. Spawning peak in summer (Hawaii).
Distribution: Atlantic: broadly tropical pattern (thermophilic eurytropical subpattern), between about 40° N-33° S (western sector) and 34° N-13° S (eastern sector) and in Agulhas Water pockets in eastern South Atlantic; exhibiting dwarfing over minimum region off Brazil and relatively lower abundance between 20° N and 7° N in eastern Atlantic. Elsewhere: Indian Ocean in Mozambique Channel and southwards in Agulhas Current; Pacific in warmer waters of eastern Pacific south to 33° S and in the Kuroshio Current north to 30° N.
Eggs, larvae and yoUng stages. No data.
Otoliths (sagitta). No data.