Ranitidine is a competitive, reversible inhibitor of the action of histamine at the histamine H2-receptors, including receptors on the gastric cells. Ranitidine does not lower serum Ca++ in hypercalcemic states. Ranitidine is not an anticholinergic agent.
1 The Blue Marlins have a diet of: Octopi, squid and pelagic fish such as black fin tuna and frigate mackerel.  They do prefer to hunt alone and during the day, rather than in schools, so it is safe to say they are a rather antisocial species.
Quick Answer. Blue marlins eat a variety of fish, including tuna and tuna-like fish, mackerel and younger members of the Balistidae and Acanthuridae families. They also eat squid and crustaceans. Blue marlins take prey from the open seas and the bottom of the ocean.