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.
Southern flounders eat a wide variety of food items, including shrimp, mullet, anchovies, croakers, and menhaden (pogies). One research project in Texas reported southern flounders to be the dominant fish predator on brown shrimp during the spring in Galveston Bay.