The difference between flat crab and swimming crab

The flat crab generally refers to the sword crab, also known as the hairy crab. The whole body is orange, the forehead has white spots on the big chelicel and the swimming limbs, and there is a purple stain at the end of the swimming limbs. The nail width is 1.8 places of the nail length. The body color of swimming crab varies with the surrounding environment. The head cuirass is light gray green, the front gill area has a round white spot, most of the cheliceps are purple with white spots, and part or the whole ventral surface is white.

I. Introduction to Portunus saberus

The animal is a member of the family Portunidae. It is distributed in Japan, Sumatra, new Zealand, Australia, Sri Lanka, India coast, Mauritius, Madagascar and Guangxi, Guangdong, Fujian and other places in the mainland of China. Its living environment is seawater, mainly living on the muddy and sandy seabed of 10-100 meters.

II. Introduction to Portunus

Portunus, some places commonly known as "white crab." Because the head cuirass is shuttle-shaped, it is named shuttle. The center of the shell has three protrusions, so it is also known as "three warts swimming crab", belonging to arthropods. Distributed in Japan, Korea, Malaysia, the Red Sea and most of the coastal areas of the mainland of China.

The mating season of swimming crab is from April to early winter in Yellow Sea and Bohai Sea, and from March to April to November to December in Fujian coast. Besides the mating of sexually mature individuals, the females that have not fully developed can also accept mating sometimes. From April to May every year, female crabs migrate and gather near coastal shallow sea harbors or estuaries to reproduce. The fertilized eggs produced are held on the abdominal limbs. Each female crab can lay 2 to 3 eggs in the breeding season, totaling about hundreds of thousands to 2 million eggs. The eggs just laid are yellow and turn black and brown after about 2 weeks. Hatching for zoea larvae, plankton life, a total of 5 stages, after the fifth molt into megalopa stage, and then molt once to become young crabs, from small to about 20 times molt. The average life span is about 3 years. Portunus trituberculatus grows very fast, with a maximum weight of 0.5 kg.