The gafftopsail catfish, Bagre marinus, is found in the waters of the western central Atlantic Ocean, as well as the Gulf of Mexico and the Caribbean Sea. It has long venomous spines which can cause painful wounds. It feeds on crustaceans and other fish. The male of the species fertilizes the eggs of the female, and broods them in his mouth until they hatch. The gafftopsail feeds throughout the water column. This fish is a common catch in the Southeastern US, although it may be found as far north as New York. They are strong fighters. They are taken from piers, jetties, reefs, and the surf, as well as bottom fishing or flats fishing. They are caught with lures, cut bait, and shrimp, as well as soft plastics. Some fishermen use traps for catfish, which is regulated by some states.
It also lives on the coastlines from Cape Cod to Venezuela. It is found in brackish waters, including estuaries, lagoons, brackish seas, and also mangroves.
The gafftopsail catfish is blue-grey to dark brown with a light grey belly. Its appearance is typical for a catfish except for the deeply forked tail and the venomous, serrated spines. It also has a little hump that looks somewhat like a wave. The typical length of a mature gafftopsail catfish is about 17 in (43 cm). The anal fin is a few inches anterior to the tail and is white or pale blue, with 22-28 rays on it and a high, anterior lobe. The pelvic fin is 6–12 in (15–30 cm) anterior to the tail fin. The gafftopsail catfish has maxillary barbels and one pair of barbels on the chin. It resembles the hardhead catfish, but its dorsal spine has a distinctive fleshy extension (like the fore-and-aft topsail of a ship).