Scopeloberyx robustus (Günther 1887)

Scopeloberyx robustus

This species is rare in the Ocean Acre area. It is represented by 20 specimens in the Ocean Acre collections, 5 of these in discrete-depth, noncrepuscular samples from the paired cruises. Five were taken between June and September and 15 between December and April. Evidently the Ocean Acre is near the southern limits of its range in the northwestern Atlantic, where it occurs between about 30° to 40°N.

DEVELOPMENTAL STAGES.—The 20 captures consist of 2 postlarvae 13–15 mm; 14 juveniles 16–27 mm; and 4 adults 46–50 mm.

VERTICAL DISTRIBUTION.—The 13 mm postlarva was caught at night at 125–150 m in a discrete-depth sample. The 15 mm postlarva, which was undergoing metamorphosis, was taken during the day in a discrete-depth sample at 950–1000 m. At night, a juvenile was caught in a discrete-depth sample from 1200–1300 m. Ten juveniles came from open-nets sampling maximum depths from 970–1550 m during the day and three from open nets to 1250–1400 m at night. Two adults were caught in discrete-depth samples; one during the day at 1500–1550 m and one at night at 1475–1550 m. The other two adults came from open-nets sampling maximum depths of 2250 and 3500 m. Based on their minimum depths of capture, juveniles probably occupy somewhat shallower depths than adults. This spiecies shows no evidence of diel migratory behavior.