Live prawns are generally used as bait when fishing for grouper.

Grouper

Introduction: Grouper belongs to the order Perciformes, with a long oval body and slightly flat sides. The mouth is large, equipped with an auxiliary maxilla, and the teeth are thin and pointed, and some are enlarged into canines. The body is covered with small comb scales, sometimes buried under the skin. The dorsal fin and anal fin have well-developed spines, the caudal fin is round or concave, and the body color varies greatly, often brown or red, with stripes and spots. It is a large and medium-sized warm-water marine fish. Grouper is rich in nutrients and has tender and white meat, similar to chicken. It is known as "Chicken of the Sea". Grouper is also a high-quality edible fish with low fat and high protein. It is promoted by Hong Kong and Macao as one of the four famous fish in China.

Appearance characteristics: Grouper body characteristics are similar, generally long in the middle, flat on the sides, brightly colored, with many variations, often brown or red, with stripes and spots, large mouth, thin and pointed teeth. , some enlarged into canine teeth, dorsal fin and anal fin hard spines, very developed, red-spotted grouper and moire grouper, ? blue grouper because the body color is greenish brown, so it is also called blue grouper, is the most produced in Fujian One of many. The grouper has an oval body, flat sides, a large head, a short and blunt snout, a large mouth, well-developed pavement bones, small comb scales on the body, and a powerful dorsal fin. The body color can change with environmental changes. The body length of adult fish is usually 20 to 30 cm. In Sea Area 214 of the East China Sea, a grouper about 1.70 meters long and weighing 51 kilograms was caught using an electric fishing rod.

Life habits:

Groupers are carnivorous and ferocious fish, preying on benthic crustaceans, various small fish and cephalopods by surprise.

This kind of fish likes silence and is afraid of waves, likes warmth and is afraid of cold, and likes purity and is afraid of turbidity. It is often seen on the seabed at a depth of 10 to 15 meters, especially in rocky caves and coral areas. It is small, active in shallow waters, active and easy to fish. Large individuals like to lie quietly and live in seclusion, often staying in caves or deep waters.

Growth and reproduction:

1. Grouper is hermaphroditic and has gender switching characteristics. When they first reach sexual maturity, they are all females, and then convert into males the following year. Therefore, there are significantly fewer males than females.

2. Salmon-spotted grouper is a batch spawning type. Oocytes of different phases in the same ovary. Even in mature ovaries at egg-laying stage V, there are many oocytes from phases 3 to 4, and there are no signs of degeneration, indicating that the development of oocytes is asynchronous. When environmental conditions are suitable, oocytes can still develop to maturity, and eggs can be matured and produced in batches during a reproduction cycle. Red-spotted grouper is a one-time spawning type, but during the reproductive season, the sexual maturity and reproduction of individuals are divided into different stages. Individuals that mature first reproduce early, and individuals that mature later reproduce later. However, it has been observed that the entire spawning cycle of red-spotted grouper can last for 2 to 3 months, and is divided into three stages: early, middle and late. Each period spawns multiple times in succession, and the middle period is the peak spawning period, so The eggs laid account for more than half of the total number of eggs. The total number of eggs laid by individual groupers ranges from 70,000 to more than 1 million eggs, with large species having 10 million eggs.

Habitat environment:

Groupers mostly inhabit tropical and temperate oceans. They like to inhabit areas with rocky reefs, gravel, and coral reef substrates near coastal islands. They generally do not form groups. The habitat water layer rises and falls with changes in water temperature. It is distributed in water depths of 10 to 30 meters in spring and summer, and also appears in water depths of 2 to 3 meters in midsummer. When the water temperature drops in autumn and winter, it swims to deeper waters of 40 to 80 meters. The suitable temperature range is 15~34℃, and the optimal water temperature is 22~28℃. It has a wide salt range and can survive in waters with salinity above 10‰.