Let's follow the great barracuda from shallow water to deeper reef. Young barracudas grow up among mangroves and seagrass, where they can hide. By its second year, a young great barracuda moves from its shallow nursery to deeper reef. A great barracuda is ready to breed at a length of roughly 60 centimeters (2 feet). A male is about 2 years old, and a female about 4, when they can first breed. A great barracuda does not look after its eggs. They drift away in the open water.

Adult great barracudas often swim alone. But young great barracudas, and some adults, travel in schools during the day. Great barracudas are most active in the daytime. They swim mostly at or near the surface of the sea.

A great barracuda finds its prey mostly by sight. It has large eyes. It hunts by ambush: it lies in wait and then surprises its prey. Great barracudas sometimes herd schools of fish into shallow water. A great barracuda is dark on top and silver and white underneath. Its dark back and light belly make it hard to see in the water.

A barracuda has a long, slim body shaped like a torpedo. The biggest great barracudas grow to about 2 meters (6.5 feet) long. A great barracuda has two dorsal (back) fins that are set far apart. Its tail fin is slightly notched in the middle, with pale tips on each side. It has a large mouth with many sharp teeth. Barracudas eat mostly other fish, and sometimes squid, octopus or shrimp. A barracuda swallows small fish whole and cuts bigger fish into pieces to swallow.

In some places, great barracudas carry ciguatoxin, a natural toxin that can make people sick if they eat the fish. Ciguatoxin is made by tiny reef algae-like organisms. Small fish eat them, and the toxin builds up in the bigger fish that eat those fish.

Great barracudas live in warm seas around the world. They have been found in the Atlantic, Indian and Pacific Oceans, and in the Red Sea. They are rare or missing in the eastern Pacific Ocean. In the western Atlantic Ocean, they live from Massachusetts, in the United States, south to Brazil. They live around coral reefs, seagrass beds and mangroves, and have been found as deep as about 100 meters (325 feet). Great barracudas live at least 14 years.

Words to know

• nursery: young fish home
• ambush: wait and surprise
• ciguatoxin: natural toxin
• schools: groups of fish
• breed: have young