While battling the marlin, Santiago catches a “dolphin” or a “dorado.” The name dolphin refers to two sea creatures: a large sea-going mammal called a dolphin, or porpoise, and a fish, the dolphinfish or mahi-mahi that sports a greenish-gold cast and a dorsal fin that stretches the entire length of its body. Mahi-mahi can grow to several feet and 90 pounds; they are a common food fish the world over. It is a mahi-mahi, then, that helps sustain Santiago during the long battle with the marlin.

Twice, Santiago uses his harpoon to kill a large fish. The first time, he raises it above his head, like a bullfighter in an arena, and thrusts it down, deep into the side of the marlin and through its heart. The second time, he uses it against a large shark that takes a big chunk out of the marlin’s flesh. This second use is more brutal, as Santiago drives it through the shark’s head. The shark jerks away and swims off to die, taking the harpoon with it and removing from Santiago’s limited armory his best weapon. Santiago jury-rigs a second harpoon by lashing his knife to an oar. That weapon, too, is soon lost, along with a makeshift club fashioned from an old oar handle.