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 Bastion portion, now a geological research and exhibition facility. The bastion is a listed building with the Gibraltar Heritage Trust. While St. Jago's Bastion has been said to be an early name for Flat Bastion, it has a separate listing with the Gibraltar Heritage Trust, next to those for Flat Bastion and Flat Bastion Magazine. The Spanish began construction of Flat Bastion in the 16th century, in 1552, at which time it was referred to as St. Jago's or Santiago's Bastion (). According to Dr. Darren Fa and Professor Clive Finlayson, both of the Gibraltar Museum, Flat Bastion was built by