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").
The Fish Can Sing young lady named Blær, which is why Björk Eiðsdóttir chose this name for her daughter born in 1997, although it was officially a masculine name. In 2013, Björk and Blær won a court case for the right to use this name—see also Icelandic Naming Committee#Blær Bjarkardóttir Rúnarsdóttir The Fish Can Sing The Fish Can Sing () is a 1957 novel by Icelandic author Halldór Laxness, who was awarded the Nobel Prize in Literature in 1955. The novel is set at the start of the twentieth century and deals with the orphaned boy Álfgrímur, his adoptive grandparents, and the small, tolerant