The barracuda is a ray-finned fish known for its large size and fearsome appearance. Its body is long, fairly compressed, and covered with small, smoothscales. Some species can reach up to 1.8m in length and 30cm in width.The barracuda is a salt water fish of the genus Sphyraena, the only genus in the family Sphyraenidae, and is found in tropical and subtropical oceans worldwide.

Barracudas are elongated fish, pike-like in appearance, with prominent sharp-edged fang-like teeth, much like piranhas, that are all of different sizes which are set in sockets of their large jaws. They have large pointed heads with an under bite in many species. Their gill-covers have no spines and are covered with small scales. Their two dorsal fins are widely separated with the anterior fin having five spines, the posterior fin having one spine and nine soft rays. The posterior dorsal fin is similar in size to the anal fin and is situated above it. Thelateral line is prominent and extends straight from head to tail. The spinous dorsal fin is placed above the pelvic fins and is normally retracted in a groove. The caudal fin is moderately forked with its posterior edged double-curved and is set at the end of a stout peduncle. The pectoral fins are placed low on the sides. Their swim bladder is large.

In most cases, they are dark green, dark blue, or gray on their upper body with silvery sides and chalky-white belly. Coloration varies somewhat between species. For some species, there are irregular black spots or a row of darker cross-bars on each side. Their fins may be yellowish or dusky. Barracudas live primarily in oceans, but certain species such as the Great Barracuda live in brackish water.

Some species grow quite large, such as the European barracuda, barracouta or spet ( S. sphyraena), found in the Mediterranean Sea and eastern Atlantic; the Great barracuda, picuda or becuna ( S. picuda), ranging on the Atlantic coast of tropical America from North Carolina to Brazil and reaching Bermuda. Other barracuda species are found around the world. Examples are the California Barracuda ( S. argentea), extending from Puget Sound southwards to Cabo San Lucas; the Indian barracuda ( S. jello) and the black-finned or Commerson's barracuda ( S. commersoni), from the seas of India and the Malay Peninsula and Archipelago.