Author: Cuvier, 1829
Argyropelecus olfersi Cuvier, 1829
Status in World Register of Marine Species:
Accepted name: Argyropelecus olfersii (Cuvier, 1829) (updated 2009-06-25)
Diagnosis: body laterally compressed, deep; eye tubular, directed dorsally; mouth vertical; enlarged caniniform teeth in lower jaw; gillrakers on first arch 15-17; branchiostegal rays 10, 3 on epihyal. Dorsal finrays 9 followed by a dorsal adipose fin; pectoral finrays 10-11(12), pelvic finrays 6, anal finrays 7 + 5. Upper preopercular spine short, extending little, if at all, beyond posterior edge of preopercle; lower preopercular spine strong, ventrally directed but hooked anteriorly in adults, to nearly vertical in juveniles and metamorphic post-larvae where its length is usually equal to (more than 85%) or longer than ventral length of anterior two PV photophores; post-abdominal spines equal in size and length; mid-anterior projection of antero-ventral post-abdominal spine short, not extending more than one-third the distance to anterior margin of posterior ventral keel scale. Dorsal blade, temporal ridges, ventral margin of ventral keel smooth; sub-caudal, sub-VAV, anal fin lacking spines. Vertebrae (35) 36-38. Swimbladder well developed, gasfilled, euphysoclistous. Scales deciduous. Photophores (adult): ORB 1, pigmented, directed towards eye lens; BR (6); OP 3, OP3 first to develop; IP (6); PV (12); VAV (4); ACI (6); AC2 (4); OA (2) + 6; VAV, AC1 and AC2 groups well separated, the photophores of each sharing a common photogenic mass; VAV, AC1 and AC2 elevated relative to posterior 6 OA. Colour: back dark, flanks silver; dorsalmost pectoral ray pigmented (fishes over about 20 mm SL) distal caudal pigment flash on outer dorsal and ventral rays (over about 21 mm SL)- abdominal ventral keel scales below fifth to eighth PV without pigment extension to ventral margin in adults. Size: to about 70 mm.
Habitat: oceanic, mesopelagic at 100-800 m; adults and juveniles at 200-800 m (day), 100 (sometimes shallower) 600 m (night), pre-metamorphic larvae at 100-300 m; adults, juveniles and (?) advanced metamorphic post-larvae make short diel vertical migrations. Food: no data. Reproduction: dioecious; adult photophore complement acquired at about 16-17 mm SL.
Distribution: in Atlantic restricted to area east of about 35° W, between about 35 and 65° N; probably absent from Mediterranean but 'Argyropelecus olfersi . . . reported from eastern Mediterranean (Lebanon) by George et al. (1964), simply quoting .... without details.' (Tortonese and Hureau, 1979)
Eggs, larvae and young stages. No data.
Otoliths (sagitta). No data.