Author: Cocco, 1829
Diaphus metopoclampus Cocco, 1829
Status in World Register of Marine Species:
Accepted name: Diaphus metopoclampus (Cocco, 1829) (updated 2009-06-25)
Diagnosis: dorsal finrays 15 (16, rarely 14); anal finrays 15 (rarely 14 or 16); pectoral finrays 10-11. Gillrakers 8 (9, rarely 7) + 1 + 14-15, total 23-24 (25, rarely 22). AO 6 + 6 (5, rarely 7), total 12 (11, rarely 13). Size: 77 mm (max.).
Habitat: high-oceanic, mesopelagic (but possibly epibenthic in western Mediterranean basin). Bermuda: day at 500-800 m; night at 300-800 m. Generally: day at 375-800 m (maximum abundance at 500 m); night at 90-850 m (maximum abundance at 200-250 m). Some size stratification with depth at night. Non-migrants include all size groups (Bermuda). Food: no data. Reproduction: sexually mature from about 48 mm. Spawning in North Atlantic may be restricted to regions north of 25° N, east of 40° W.
Distribution: probably a rare migrant in the Mediterranean. Atlantic: subtropical pattern (bisubtropical subpattern); North Atlantic: 20°-53° N, with isolates to 6° N (eastern sector), and mainly north of Gulf Stream edge (western sector), but with isolates to Gulf of Mexico and South Sargasso Sea; South Atlantic: 27°-40° S, but with isolates from about 18° S (western sector), and south of 30° S (eastern sector). Elsewhere: Indian Ocean (west of 70° E, between 0° and 30° S) and Pacific (western sector between 6° and 39° N and near Hawaii).
Eggs, larvae and young stages. ? Sanzo, 1918: 55 | Sparta, 1952: 5-10, fig. 1-5.
Otoliths (sagitta). Kotthaus, 1972a: 13, 26, fig. 69.