Longfin grouper

The longfin grouper has an elongated body, 2.8 to 3.2 times longer than its depth. The head is smoothly curved, with an almost straight upper edge of the gill cover. The dorsal fin consists of 11 sharp spines and 16–18 soft rays, while the anal fin has 3 spines and 8 soft rays. The caudal fin is rounded, and the pectoral fins are nearly twice as long as the head. The fish's coloration is light with numerous dark spots that form a dense pattern on the upper body and head, while the spots are sparser and less defined on the lower body. Similar spots can be seen on the dorsal, anal, and caudal fins.

There are two dark bands on the chest that meet under the pectoral fin, forming a light spot on the lower chest. Another light spot is found between these bands and the dark spot at the base of the pectoral fin. Dark spots and stripes are visible on the throat and chest. The spots on the head become smaller towards the nose but are still larger than the fish’s nostrils. There is also a light square spot on the cheek near the upper jaw. The rear edges of the fins are darkened, with faint spots, and the front edges of the pelvic fins have a white line and a dark streak.

The longfin grouper is found in the Indo-Pacific region, including the waters of the Indo-Malay Archipelago, the Andaman Islands, and the northern coast of Australia. It prefers silty reefs and sandy bottoms at depths of up to 50 meters.

It feeds on worms, small fish, and crustaceans. This species is an ambush predator, often waiting for prey in hiding.

The longfin grouper poses no threat to humans. However, it can become territorial when threatened and may defend its habitat.

The longfin grouper is a protogynous hermaphrodite. All individuals start as females and become sexually mature at around 24 cm in length. Later, when they reach around 33 cm, they change sex and become males.

This species was first described in 1830 by French zoologist Achille Valenciennes and named in honor of Jean René Constant Quoy, a French naval surgeon and naturalist.