About Mycteroperca venenosa (Linnaeus, 1758)
The yellowfin grouper, Mycteroperca venenosa (Linnaeus, 1758), has an elongated, robust, compressed body. Its body depth at the origin of the dorsal fin is not greater than its body depth at the origin of the anal fin, and standard length measures 2.6 to 2.9 times the body depth. The preopercle is neatly rounded, sometimes with a small incision, and lacks a lobe at its angle. The dorsal fin holds 11 spines and 15–16 soft rays, while the anal fin holds 3 spines and 10–12 soft rays. The membranes between the dorsal fin spines are clearly notched. The caudal fin is straight in juveniles and slightly concave in adults. The head and body are marked with oval groups of dark spots, and the outer third of the pectoral fin is bright yellow. There are two distinct color morphs: a reddish morph found in deep water, and a greenish morph found in shallow water. This species reaches a maximum total length of 100 centimetres (39 in), though individuals are commonly around 45 centimetres (18 in), and has a maximum published weight of 18.5 kilograms (41 lb).
The yellowfin grouper is distributed in the western Atlantic Ocean. Its range runs along the U.S. Atlantic coast from North Carolina south to Florida, and extends into the Gulf of Mexico, where it occurs in the Florida Keys and Texas' Flower Garden Banks National Marine Sanctuary. It continues south through the Bahamas into the West Indies and Mexico's Yucatan Peninsula, and is also found around Bermuda. Along the Caribbean coast of South America, it occurs as far east as French Guiana. It is also found along the Brazilian coast from Maranhão to São Paulo, including the islands of Trindade and Fernando de Noronha.
Adult yellowfin groupers live over rocky or coral reefs, while juveniles are found in turtle grass beds. This species has also been caught by trawlers over muddy bottoms in the Gulf of Mexico. It inhabits depths ranging from 2 to 137 metres (6.6 to 449.5 ft). It is a protogynous hermaphrodite: females reach sexual maturity at a fork length of around 51 centimetres (20 in) and an age of around 4.6 years, then change sex to male at a fork length of 80.1 centimetres (31.5 in). It forms spawning aggregations that occur at different times of year across different parts of its range. This species is mainly piscivorous; over 90% of sampled stomach contents were reef fishes, with a small amount of squid also recorded.
