Cyclothone braueri

Author: Jespersen and Tåning, 1926

Cyclothone braueri Jespersen and Taning, 1926

Status in World Register of Marine Species:
Accepted name: Cyclothone braueri Jespersen and Tåning, 1926 (updated 2009-06-25)

Diagnosis: body elongate; mouth large; premaxillary teeth even; vomer with teeth. Pseudobranch absent; gillrakers on first arch 15-17 (18), 3, rarely 4, on hypobranchial, no raker in articulation of epi- and ceratobranchial; gill filaments fused basally in broad segment shape along hypobranchial. Meristic data (eastern North Atlantic and Mediterranean): branchiostegal rays 13 (12-14), 5 (6) on epihyal. Dorsal finrays 13-14; pectoral finrays 9-10; pelvic finrays 6 (7); anal finrays 18-20; dorsal and anal fin origins about opposite; last dorsal and anal finrays not split to base; adipose dorsal fin absent; anus close to pelvic fin bases. Vertebrae 31 (30-32). Scales absent. Photophores: SO absent, ORB I, OP 2, BR 9 (8-10), IV 3 + 10; VAV 4, first two close together, anterior to genital opening, remainder evenly spaced; AC 13 14, 1 between last anal and first procurrent ray; OA 7; opercular and pre-caudal glands inconspicuous. Colour: white ground colour with stellate melanophores confined mainly to epaxial region; brown pigment conspicuous between anal pterygiophores; membrane between posteriormost branchiostegal rays transparent or at most with single stellate melanophore between each pair of rays; meningeal pigment comprised dorso-anteriorly of few stellate melanophores. Size: male to 26 mm, female to 38 mm SL.

Habitat: oceanic, mesopelagic; precise depth range dependent upon developmental stage, latitude, season: pre-metamorphic post-larvae at less than 10-50 m metamorphic post-larvae at 400-600 m, juveniles and adults at 250-900 m (sometimes shallower); generally horizontally orientated (submersible observations); in Atlantic north of 40° N and in Mediterranean, seasonal vertical displacement (about 200 m) of adults, individuals Iying shallower in midwinter than midsummer. Food: mainly copepods. Reproduction: dioecious; spawning season mainly April-October. Ripe eggs about 0.5 mm diameter; ovulation all or none, with 100-900 eggs/ovary pair, fecundity increasing in higher latitudes; length at metamorphosis 11-14 mm SL.

Distribution: circumglobal; temperate and subtropical in North Atlantic and Mediterranean. Abundant in Clofnam area to 60° N; northern record 66°56'N, 14°41'W.

Eggs, larvae and young stages. Grey, 1964: 185.
Otoliths (sagitta). No data.