Spot, fish in the croaker family. The spot (Leiostomus xanthurus) inhabits the coastal waters of the Atlantic Ocean and the Gulf of Mexico. It is caught for sport and has a commercial value because it is edible. A dark spot at the pectoral fin, or shoulder, of this fish is its most prominent characteristic. It is 6–10 in (15–25 cm) long and weighs about 0.5 lb (0.2 kg).