Wahoo (Acanthocybium solandri) is a scombrid fish found worldwide in tropical and subtropical seas. It is best known to sports fishermen, as its speed and high-quality flesh makes it a prized and valued game fish. In Hawaii, the wahoo is known as ono. The species is sometimes called hoo in the United States. Description Its body is elongated and the back is an iridescent blue, while the sides are silvery with a pattern of irregular vertical blue bars. These colors fade rapidly at death. The mouth is large, and the teeth of the wahoo are razor sharp. 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 in length, and weighing up to . Growth can be rapid. They are among the fastest fish in the sea. The wahoo may be distinguished from the related Atlantic king mackerel and from the Indo-Pacific narrow-barred Spanish mackerel by a fold of skin that 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 the smaller Spanish mackerel and Cero mackerel. The teeth of the wahoo are similar to those of king mackerel, but shorter and more closely set together. The barracuda is sometimes confused with the mackerel and wahoo, but it is easy to distinguish from the latter two species. Barracuda have prominent scales and larger, dagger-like teeth, and lack the caudal keels and blade-like (forked) tail characteristic of the scombrids. Distribution Wahoo have a circumtropical distribution and are found in Atlantic, Pacific, and Indian Oceans. Population genomic research using RAD sequencing indicates that two weakly differentiated fish stocks are in the Atlantic and Indo-Pacific Oceans, likely with a considerable degree of migration and gene flow between these populations. Lifecycle The eggs of the species are buoyant and the larvae are pelagic. Wahoo tend to be solitary or occur in loose-knit groups of two or three fish. Where conditions are suitable, they can be found in schools around 100 or more. Ecology Their diet is made up of other fish and squid. From a study surrounding the Western and Central Pacific Ocean (WCPO), an analysis of the stomach contents of wahoo indicated that their diet consists of 84.64% native fish, 14.26% cephalopods (e.g. cuttle fish), and 1.1% crustaceans. The gender ratio of