The wahoo (Acanthocybium solandri) is a dark blue scombrid fish found worldwide in tropical and subtropical seas. Its speed and high-quality flesh make it a prize game fish. In Hawaii, the fish is known as ono. Hispanic areas of the Caribbean and Central America call it Peto.
The body is elongated and covered with small, scarcely visible scales; the back is an iridescent blue-green, while the sides are silvery, with a pattern of vertical blue bars. These colors fade rapidly at death. The mouth is large, and both the upper and lower jaws have a somewhat sharper appearance than those of king or Spanish mackerel. Specimens have been recorded at up to 2.5 m (8 ft) in length, and weighing up to 83 kg (180 lb). Growth can be rapid. One specimen tagged at 5 kg (11 lb) grew to 15 kg (33 lb) in one year. Wahoo can swim up to 80 km/h (50 mph), Firestein and Walters, 1969. They are one of the fastest fish in the sea.
The wahoo may be distinguished from the related king mackerel by a fold of skin which covers the mandible when its mouth is closed. In contrast, the mandible of the king mackerel is always visible as is also the case for Spanish and Cero mackerels. Their teeth are similar to those of king mackerel, but shorter and more closely set together. Do not mistake Barracuda for Wahoo. Barracuda have prominent scales, are greenish in color and lack the characteristic blade-like tail characteristic of the mackerel/tuna family of fish.
Wahoo tend to be solitary or occur in loose-knit groups of two or three fish, rather than in schools. Their diet consists essentially of other fish and squid.
Most wahoo taken have a trematode parasite (Hirudinella ventricosa) living in their stomach. It appears to do no harm to the fish.