The escolar, Lepidocybium flavobrunneum, a species of fish in the family Gempylidae, is found in deep (200–885 metres, or 656–2,904 ft) tropical and temperate waters around the world. It is also known as snake mackerel, walu walu (Hawaiian, sometimes written waloo), and is sometimes sold as "butterfish" or "white tuna".
The escolar is dark brown, growing darker with age until it is quite black. It is a fast-swimming fish with a prominent lateral keel and four to six finlets after the anal and second dorsal fins. Escolar can grow to over 2 metres (7 ft) in length. Like its relative the oilfish (Ruvettus pretiosus), escolar cannot metabolize the wax esters (gempylotoxin) naturally found in its diet. This gives the escolar an oil content of 14–25% in its flesh.
