- Black sea bass have dangerously sharp spines on their dorsal fin that can puncture human skin.
- The all-tackle world record for black sea bass is 9 pounds, 8 ounces.
- When hooked in deep water and brought quickly to the surface, a black sea bass will often regurgitate its stomach contents.
Gag have elongated but compressed bodies typical of all grouper and sea bass. Coloration is brown-gray to olive-gray with dark, irregular wavy markings on the side. The skin has a marbled quality to it, and the color of the gag deepens to dark brown after removal from the water. The anal, pelvic and tail fins are black with blue or white edges. The mouth is moderately large and the connected dorsal fins cover most of the back. Gag are often confused with black grouper but can be distinguished by differences in the tail: the back of the gags tail is slightly concave while the back of the black groupers tail is flat.
Gag are found in the western Atlantic from North Carolina to the Yucatan Peninsula, Mexico. Occasionally, juveniles will be found as far north as Massachusetts and as far south as Brazil.
In general, adult gag are an offshore species that occupy coral reefs, rocky bottoms and wrecks in waters from 60 to 300 feet deep. However, they can sometimes be found inshore over rocky or grassy bottoms. They are the most common grouper species on the rocky ledges along the eastern Gulf of Mexico. Juvenile gag are found inshore, often in sea grass beds. Adults are mostly solitary but can also be found in groups up to 50 individuals.
Gag, like other grouper, form large spawning aggregations. These groupings occur from January to March in water 120 feet or deeper. No nests are built, and eggs are scattered and left floating after fertilization. After hatching, young gag move inshore among the sea grass.
The main component of the gags diet is fish, especially sardines, porgies, grunts and snappers. They also eat crustaceans such as crabs and shrimp, as well as squid. Gag are mainly ambush hunters that rush out of crevices and caves when prey swim by.
Gag are hard fighters and excellent table fare. Because they are found in shallow water more frequently than other grouper, gag are the best grouper for fly-fishing. They are normally caught by bottom fishing with 50- to 80-pound test lines in deep waters, or by trolling with large deep-diving plugs in shallower water. Good live bait are pilchards, pinfish, grunts or sand perch.
- The generic name black grouper is applied to at least three different species of grouper, with the gag possibly being the species incorrectly given that name most often.