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").
Coastal fish (flatfish) such as plaice which live "on" the sea bed. Benthic fish tend to be "flat", so they can lie on the bottom. Stargazers are about 50 species of fishes, belonging to the family Uranoscopidae, and found worldwide in shallow waters. Stargazers are venomous; they have two large poison spines situated behind the opercle and above the pectoral fins. They can also deliver electric shocks. They are ambush predators with eyes on top of their heads (thus the name). Stargazers also have a large upward-facing mouth in a large head. They bury themselves in sand with only their eyes showing,