Seahorses occupy a middle position in their food chain. They are carnivores that feed on tiny crustaceans, such as shrimp. The shrimp feed on algae, which are near the base of the food chain. Seahorses are preyed upon by crabs and fish, which are eaten by larger fish. These large fish are hunted by apex predators, including sharks that are at the top of the food chain.
Seahorses use their prehensile tails to anchor themselves to plants or coral. Because they are sedentary and camouflage easily, they can ambush their prey at any moment. When shrimp and other small organisms swim by them, seahorses quickly suck them in with their elongated snouts. They feed continuously and can eat as much as 3,000 brine shrimp in a day.
Seahorses are slow, rather inept swimmers that tire easily, so they use their natural camouflage to hide from predators. Seahorses are often captured as specimens for aquariums. Humans also fish for them in East Asia because the natives there believe that seahorses have medicinal properties. The Convention on International Trade in Endangered Species of Wild Flora and Fauna attempts to control the import and export of seahorses, although several nations have opted out of these regulations.