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").
Peters' elephantnose fish fish can use its electosensing to detect moving prey and worms in the substrate. Although the elephant nose fish was once thought to have poor eyesight, it is now known to have good low light vision. Its eyes use a combination of photonic crystals, parabolic mirrors and a clustered arrangement of rods and cones. Peters' elephantnose fish Peters' elephant-nose fish ("Gnathonemus petersii") is an African freshwater elephantfish in the genus "Gnathonemus". Other names in English include elephantnose fish, long-nosed elephant fish, and Ubangi mormyrid, after the Ubangi River. As the Latin name "petersii" confirms it is named after someone called