Distribution of producing area of swimming crab

Swimming crab is an important economic crab along the coast of China, with rapid growth, rich profits, delicate and white meat, rich in protein, fat and a variety of minerals, and has become an important breeding species in China's coastal areas. individuals are the most robust in the winter swimming season, weighing about 250 grams and up to 500 grams. Let's take a look at the distribution of swimming crabs.

Distribution of producing area of swimming crab

Swimming crab is one of the most important export bestsellers in China, which is mainly exported to Japan, Hong Kong, Macao and other countries and regions, and its producing areas are mainly distributed in Liaoning, Hebei, Tianjin, Shandong, Jiangsu, Zhejiang, Fujian and other sea areas. generally from south to north, March to May and September to October are the peak production seasons, and the Liaodong Peninsula in Bohai Bay produces more from April to May. Japan, Korea, Malaysia and the Red Sea are also distributed.

Environment of producing area of swimming crab

1. Water temperature: the suitable water temperature of swimming crab is 8-31 ℃, and the optimum water temperature for growth is 15.5-26.0 ℃. The activity of Portunus trituberculatus is different in different water temperature. When the water temperature is ~ 1.5 ℃, no food is eaten, and some individuals freeze to death in shallow water. At 0: 6 ℃, they did not take food, buried sand day and night, and were in a state of eye rest. Began to stop feeding at 8: 10 ℃, weak activity, lurking in deep water. At 14 ℃, the food intake decreased and began to move to the deep area, and the activity was normal. At 15-26 ℃, the food intake was large, the activity was normal, and the growth was fast. At 17: 21 ℃, the mating peak. At 14-21 ℃, the egg-holding population began to be found. At 12: 14 ℃, it begins to lay eggs.

2. Salinity: the suitable salinity of swimming crab is 1338, and the optimum growth salinity is 2035. The salinity of overwintering adaptation is 2835. If the salinity is lower than 8 or higher than 38, stop feeding and activity, and all die one day later.

3. Others: the adaptive range of pH value of swimming crab is 7.5-8, dissolved oxygen should not be less than 2 mg / L, and chemical oxygen consumption should not exceed 12 mg / L. Hydrogen sulfide does not exceed 0.2 mg / L. The semi-lethal concentration of copper ion within 24 hours was 58 mg / L.

Common species of swimming crab

1. Portunus trituberculatus: Portunus trituberculatus, commonly known as swimming crab and white crab, belongs to the family Portunidae of crustacea and is an important economic crab along the coast of China. With rapid growth and rich profits, it has become an important breeding species in China's coastal areas. it generally lives and breeds at a depth of 3 to 5 meters, migrates to a depth of 10 to 30 meters in winter, and likes to live in caves at the bottom of sediment. The suitable salinity is 16-35, the water temperature is 4-34 ℃, the PH value is 7-9, the optimum salinity is 26-32, and the optimum temperature is 22-28 ℃.

2. Red star swimming crab: the head and chest nail of red star swimming crab is fusiform, slightly raised, there are three prominent warty protuberances on the surface, the chelate foot is well developed, the long segment is prismatic, the inner edge has obtuse teeth, and the fourth pair of foot knuckles are flat and thin as oars, which is suitable for swimming and belongs to the bottom crabs of warm water. Distributed in Japan, Hawaii, the Philippines, Australia, New Zealand, Malaysia, the Indian Ocean to the coast of South Africa throughout the Indo-Pacific warm water area, Taiwan Island, as well as Chinese mainland Guangxi, Guangdong, Fujian and other places, the living environment is sea water. it is mostly found on the muddy seafloor at a depth of 10 to 30 meters.

3. Far-sea swimming crab: far-sea swimming crab is an animal of the genus Portunidae, distributed in Japan, Tahiti, Philippines, Australia, Thailand, Malaysia Islands, East Africa, Taiwan Island and Chinese mainland in Guangxi, Guangdong, Fujian, Zhejiang and other places. The living environment is sea water and often lives on the muddy or sandy seafloor at a depth of 10 to 30 meters. The crab nail is about 20 cm wide. Except for the movable and immovable fingers of the chelate feet and the dark blue of the front and knuckles of each foot, the rest of the crab nail is mostly turquoise and light blue or white mottled.