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").
Fish River (Alaska) of ore taken to the city for smelting and refining for silver. Walter Curran Mendenhall found obscure fossils on Fish River at White Mountain. Its Inuit name was reported in 1838 as Ikalikhvik meaning "fish (or fish place)" by Aleksandr Filippovich Kashevarov. Various spellings were reported by Western Union Telegraph Expedition in 1865–67. Dall appears to be the first to have applied the name "Fish River" in 1870 when he wrote: "Golofnina Bay is connected with a large lagoon which opens in Grantley Harbor by the extremely winding channel of the Fish River, which has one principal tributary, the Kavi-ava-zak."