Common snook or robalo, Centropomus undecimalis, is a species of marine fish in the family Centropomidae of the order Perciformes.
It grows to a maximum overall length of 140 centimetres (4.6 ft) but common length is 50 centimetres (1.6 ft). It is widespread throughout the tropical waters of the western Atlantic Ocean from the coast of the North Carolina to Brazil including the Gulf of Mexico and the Caribbean Sea. Occurring in shallow coastal waters (up to 20 metres (66 ft) depth), estuaries, and lagoons, the fish often enters fresh water. It is carnivorous, with a diet dominated by smaller fishes, and crustaceans such as shrimps, and occasionally crabs.