At the Aquarium
These fish show off their schooling ability in an exhibit in our Tropical Pacific gallery.
Indo-Pacific between east Africa and Samoa, especially southern Japan to southern Australia.
Stinging catfish are the only catfish to inhabit coral reefs. While they thrive in water that is as deep as 35 meters (115 feet) water, they also live in shallow estuaries and tide pools. Sandy ocean floors provide the fish with ideal hunting grounds and breeding areas. Adults often hide under rock or coral ledges. They have occasionally been observed in brackish and fresh water.
Stinging catfish have a scaleless, knife-shaped body with fused dorsal, caudal, and anal fins that give them give an eel-like appearance. The mouth is small and flat with eight fleshy protuberances or appendages called barbels on it, four paired on the upper jaw and four on the chin. The barbels end in a point. There is one strong, hollow, bony venomous spine on the front of the dorsal fin and each of the pectoral fins.
Adult stinging catfish have a different coloration than juveniles. Young catfish have dark grey, black, or brown bodies. There are two ivory, yellow, or white horizontal stripes on each side of the body. The belly is a pale cream or white color. As they age, the stripes fade and the body lightens to liver, tan, or chocolate. The pale underside also acquires a brownish tinge.
The largest known stinging catfish was 35 cm (13.8 in) long. Most adults reach only about 30 cm (12 in) in length.
Primarily carnivores, these fish stir up the sandy bottom of the ocean floor with their barbels to uncover hidden prey that they have smelled with taste buds on their mouth and barbels. Crustaceans, mollusks, and worms provide the bulk of their diet, but adults may eat small fish given the opportunity.
Sexes are separate. When ready to breed, male stinging catfish construct a shallow nest in rocky areas with sand. The female releases her eggs into the water and the male fertilizes them externally. It has been reported that the male guards the tiny eggs and young, but this has not been confirmed. The young fish, or fry, hatch as planktonic larvae.
Juvenile stinging catfish display an unusual schooling behavior that is more often observed in temperate and cold water fish species. Instead of simply gathering into a group, the fish form a sphere-shaped school of six to over one hundred individuals. They travel near the ocean floor in a curious revolving motion, with the upper fish exchanging places with lower fish. By using such an unusual schooling manner, all the catfish take turns keeping watch for predators while gaining the opportunity to forage. Once the fish age, however, they abandon their schools and become solitary or form groups of up to only 20 individuals.
Stinging catfish defend themselves from predators with the sharp venomous spines on the beginning of their dorsal and pectoral fins. If agitated, the fish use these spines to inject potent venom. The venom usually causes extreme pain and has been reported to have caused the death of individuals allergic to the venom.
The oldest known stinging catfish lived for seven years.
Stinging catfish are not on the IUCN Red List. Because coral reefs are one of their habitats, declines in coral reefs due to global climate changes, El Niños and other weather impacts, and impacts of human activities could require that they rely on other habitats for their survival.
Stinging catfish are occasionally found in fresh water streams in Madagascar and East Africa. Some scientists believe that they may travel into fresh water to breed as salmon do.