Author: (Lütken, 1892)
Hygophum reinhardtii (Lütken, 1892)
Status in World Register of Marine Species:
Accepted name: Hygophum reinhardtii (Lütken, 1892) (updated 2009-06-25)
Diagnosis: dorsal finrays 14 (13, rarely 15); anal finrays 22-23 (24, rarely 21 or 25); pectoral finrays 14 (13-15, rarely 16). Gillrakers 4 (rarely 3 or 5) + 1 + 13 (12-14, rarely 11 or 15), total 18 (17-19, rarely 16 or 20). AO 7 (6-8, rarely 5 or 9) + 7 (6 8), total 1415 (13, rarely 16). Males with single supra-caudal gland only; females with 3 (4) coalesced luminous patches infra-caudally, sometimes separate. Size: to 61 mm.
Habitat: high-oceanic, mesopelagic. Canaries: day at 600-800 m; night at 10-200 m (fully pigmented juveniles) and at 600-900 m (light-coloured juveniles). Bermuda: day at 600-850 m; nyctoepipelagic at surface and down to 200 m. Size stratification with depth at night (Bermuda). Light-coloured juveniles non-migratory (Canaries). Food: no data. Reproduction. caudal glands develop in males from 24 mm and in females from 2 mm; sexually mature from about 46 mm.
Distribution: Atlantic; broadly tropical pattern (holo-eurytropical sub pattern), between about 40° and 2° N, and between about 18° S anc the Subtropical Convergence (western sector) and between 5° and 30° S east of 20° W. Elsewhere, southern Indian Ocean and North and South Pacific, but absent in equatorial waters.
Eggs, larvae and young stages. Moser and Ahlström, 1970: 66-73, fig. 19-20 | Moser and Ahlström, 1974: 397, fig. 4a.
Otoliths (sagitta). Kotthaus, 1972a: 12, 26, fig. 59.