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.
In Western Australia, blue swimmer crabs can grow to up to 25 cm wide across the carapace with a claw span of up to 80 cm. They eat small fish and crustaceans, molluscs, worms, and occasionally, algae and seagrass. In turn, they are prey for fish and birds.