Sphyraena viridensis, the yellowmouth barracuda or yellow barracuda is a predatory ray finned fish from the family Sphyraenidae, the barracudas, which is found in the warmer waters of the western Atlantic Ocean and the Mediterranean Sea. It is often confused with the European barracuda Sphyraena sphyraena.
Sphyraena viridensis has a long, fusiform body with a long, streamlined pointed snout which has a long mouth lined with two rows of sharp, fang-like teeth and a jutting lower jaw. There are no scales on the preoperculum, unlike S. sphyraena which has scales on both the anterior and posterior margins of the preoperculum. There are numerous transverse dark bars on the dorsum and these are longer,extending below the lateral line, towards the head while in S. sphyraena they do not extend to the lateral line.
Generally the colouration is a countershaded dark above, silvery below and the barring fades on dead specimens. Juveniles are described as being dark yellow or greenish in colour. S. viridensis averages smaller than S. sphyraena growing to a standard length of 65 cm, although the average length is 35–40 cm. but specimens up to 114.5 cm have been caught of the Azores. The rod caught record is 10.2 kg which was caught off Lanzarote in the Canary Islands in 2007.
The exact distribution of Sphyraena viridensis is unclear because of confusion with S. sphyraena. It occurs in the eastern central Atlantic around the Azores, Madeira, Cape Verde Islands and the Canary Islands and has been recorded in the eastern Mediterranean off Lebanon. It has also been recorded in the Mediterranean in the Adriatic Sea, Aegean Sea, off Israel, Algeria, Corsica and Sicily.
In the Azores fish made up all of the diet and the most important species in the diet of Sphyraena viridensis was the bluejack mackerel Trachurus picturatus being found as having been preyed upon by 72.4% of the fish sampled and making up nearly two thirds of the weight of prey taken. Other species taken in this study included single examples of bogue Boops boops, ornate wrasseThalassoma pavo and axillary sea bream Pagellus acarnae, as well as an unidentified species of the Exocoetidae.
Unidentified fish remains were found in nearly 20% of the specimens sampled. In the same study the predatory behaviour of S.viridensis was observed and they are active pursuit predators of fish with one or many barracudas pursuing fish, either singling out lone prey or attacking shoals of prey fish.
The pursuit was rapid and was usually over in 8–40 seconds and the more fish were involved the higher the rate of success was. In these observations other fish species than those sampled from specimens were observed as prey e.g. longspine snipefish Macrorhamphosus scolopax and boar fish Capros aper. It is also known to feed on cephalopods and crustaceans.