What types of grouper are there? A detailed introduction to common varieties
Grouper is hermaphroditic, with sex-changing characteristics. At first sexual maturity, all are female, and the following year they change to male, so males are noticeably fewer than females. There are 12 species of grouper distributed along the coast of Fujian, among which the more economically valuable and relatively common species include the red-spotted grouper, the salmon-spotted grouper, the clouded grouper and the reticulated grouper.
Leopard coral grouper (common in Hainan)
The leopard coral grouper comes in colors such as blue, red, brown and yellow. Its body is slimmer and longer than ordinary groupers, and its head is small. Its blue eyes have jet-black pupils, and its body is covered with fine white spots, resembling stars in the sky, which is why it is called "star grouper"; as for the "coral" part, it is because it is produced in the Dongsha Islands in eastern China.
Green grouper
The lower part of the green grouper's body has several orange-red spots, and the sides of the body have 6 dark brown vertical stripes, with the widest gap between the 3rd and 4th bands; only the caudal fin has spots. It is a warm-water mid- and lower-layer fish. Juveniles and larvae feed on plankton, while adults feed on fish, shrimp and crabs. It is hermaphroditic, with females maturing first, and sex reversal occurs at a body length of 250-400 mm; males all reach sexual maturity at 6 years of age (a few at 5 years). Absolute fecundity is 80,000-250,000 eggs, the spawning period is from late May to July, spawning begins at 20°C, with the peak at 22-24°C, and pelagic eggs are laid. At a water temperature of 22-25°C, it takes 23-30 hours for the larvae to hatch. The flesh is delicious, and it is a valuable fish species; large quantities of live fish are sold to Hong Kong, China and Macao, China. It is a species for shallow-sea aquaculture in China and Southeast Asia, and can be raised in cages. It is distributed in Taiwan, China, the East China Sea and the South China Sea, as well as Japan.
Jewel grouper
The jewel grouper generally has a body length of 25-30 cm, and its body surface and all fins except the pectoral fins are covered with gem-like spots. The pectoral fins have red stripes, and the caudal fin is slightly concave with a white edge. It is a warm-temperate mid- and lower-layer fish, mostly living in sea areas with rocky reef bottoms, with sex reversal from female to male. Growth is relatively slow. Grouper is fierce and alert, mainly carnivorous, fond of eating fish, shrimp and crabs, does not like to form schools, and engages in cannibalism when hungry. The jewel grouper is distributed in the Indian Ocean and the western Pacific Ocean, and in China it is found in the South China Sea. Artificial cage farming is carried out in several provinces in China.
Giant grouper
Its scientific name is the giant grouper, also known as the piglet grouper. It is a warm-water marine bottom fish belonging to the order Perciformes, family Serranidae, subfamily Epinephelinae, genus Epinephelus. Its body is elongated and oval, laterally compressed, with a relatively large mouth, and the head, sides of the body and all fins are scattered with many blue-black spots. It is a large, valuable food fish. In natural sea areas, adults generally have a body length of 60 cm to 70 cm, with a maximum body length of up to 2 m, and a body weight generally around 30 kg to 40 kg, with large ones reaching 100 kg to 160 kg or more. It is recorded that in July 1999, fishermen from Hong Kong, China once captured alive a female giant grouper in the Dongsha Islands, weighing 180 kg, which was regarded as the king of giant groupers.
Orange-spotted grouper
The orange-spotted grouper has a short, blunt snout, 8-11 dorsal fin spines, no black spot at the base, 5 indistinct vertical bands on the sides of the body, and scattered spots on the sides of the body and on all fins. It is a tropical mid- and lower-layer fish, fond of inhabiting sea areas with rocky reef bottoms, and is a valuable fish species in the South China Sea. It is fierce, mainly carnivorous, fond of eating fish, shrimp and crabs, and engages in cannibalism when hungry. It can live in waters with a salinity of 11-41‰, with an optimum water temperature of 22-28°C; below 18°C appetite decreases, and below 15°C the fish loses its balance. It can be raised in cages. It is distributed in sea areas such as the East China Sea and the South China Sea of China.
Red-spotted grouper
The red-spotted grouper has a black spot at the base of the dorsal fin, a brownish body, and many orange-yellow spots on the head, body and unpaired fins (turning white in preserved specimens). It is a warm-temperate mid- and lower-layer fish. Adults feed on fish, shrimp and crabs. It is hermaphroditic, with females maturing first, most reaching sexual maturity at 3 years of age, and changing from female to male at a body length of 231-295 mm. Most 6-year-old fish (a few 5-year-old fish) have a body length of 340-400 mm, absolute fecundity is 100,000-250,000 eggs, the spawning period is from May to September, with the peak from May to June. The flesh is delicious and can be exported; it is a valuable fish species, and artificial breeding has now been carried out. It is a species for cage and shallow-sea aquaculture. It is distributed in Taiwan, China, the East China Sea and the South China Sea, as well as India and Japan.
Orange-spotted grouper
The orange-spotted grouper has an elongated body, brownish on the back of the head and body, and the belly base color is white; countless orange-brown or reddish-brown small dots are distributed on the head, body and middle of the fin rays; the body has 5 large, irregular, interrupted black spots that fork toward the belly; the first black spot is below the anterior dorsal fin spines, and the last black spot is on the caudal peduncle; 2 black spots are on the middle operculum, while another 1-2 are at the junction of the suboperculum and middle operculum. When exposed to air, the orange dots turn brown, and in preservative they become blurred.
The orange-spotted grouper often inhabits continental coasts and large islands, but can also be found in estuaries and waters up to 100 m deep offshore. The main breeding period is from March to June. Females mature at a total length of 25-30 cm (2- or 3-year-old fish), and sex change usually occurs at a body length of 55-75 cm.