Macrourus berglax shrimps, amphipods, polychaete worms, bivalve molluscs, isopods, brittle stars, other echinoderms and comb jellies. The roughhead grenadier is a slow growing fish. The females mature at an age of about 14 years and a length of while males reach maturity at a length of . The potential fecundity of the female is 17,000 to 56,000 eggs. The eggs are laid in batches and spawning takes place at any time of year, with a peak in late winter and early spring. The roughhead grenadier is landed as a by-catch when fishing for Greenland halibut ("Reinhardtius hippoglossoides") and Atlantic halibut ("Hippoglossus hippoglossus").
Flat needlefish the left gonad in both sexes is developed, and in males, the right gonad is sometimes wholly absent. Flat needlefish The flat needlefish ("Ablennes hians"), the only known member of the genus Ablennes, is a marine fish of the family Belonidae. Flat needlefish are considered gamefish, frequently caught with the help of artificial lights, but are not often eaten because of their green-colored flesh. The generic name "Ablennes" – formerly misspelled "Athlennes" – means ‘without ’, from the ancient Greek privative "a-" prefix and "blennos" (‘mucus’). Its specific name is Latin for "gaping". Although they have no spines, they do