Crabs are crustaceans. Crabs: Animalia, phylum Arthropoda, subphylum Crustacea, class Mollusca, subclass Truly Mollusca, order Decapoda, suborder Gastroembryozoa, suborder Hypostomatidae. The body is protected by a hard shell and breathes by gills. In biological taxonomy, it is in the same category as shrimp, lobster, and hermit crabs.

The vast majority of species of crabs live in the sea or offshore areas, with some inhabiting freshwater or land. They rely on the mother crab to give birth to their young, and each time she lays many eggs, which can number in the millions or more. Crabs rely on geomagnetic fields for orientation. These organisms have a complex and highly variable amount of genetic material, often upwards of 100 pairs.

Common crabs include hairy crabs (river crabs, hairy crabs, clear-water crabs) and pike crabs. China's crab resources are very rich, with the lower reaches of the Yangtze River, Gucheng Lake hairy crabs, Taihu Lake hairy crabs, Gaoyou Lake hairy crabs, Yangcheng Lake hairy crabs, Crab House hairy crabs, Xinghua hairy crabs, and Hongze Lake hairy crabs produced by the hairy crabs for the top quality.

Expanded

There are many kinds of crabs, there are about 600 kinds of crabs in our country, there are pike crabs, green crabs, frog crabs, Guan Gong crabs and so on?

There are many kinds of crabs in China.

1, pike crab, some places commonly known as "white crab". Because the cephalothorax is pike-shaped, so the name pike. There are three protrusions in the center of the carapace, so it is also known as the "three warts pike crab", belonging to the arthropods. Male umbilicus pointed and smooth, chela grows, shell surface with cyan; female umbilicus rounded with downy, shell surface ochre, or spots.

The pike crab is fat and tasty, has high nutritional value and economic value, and is suitable for seawater fattening temporarily. The cephalothorax is pike-shaped, almost twice as wide as long; the surface of the cephalothorax is covered with fine granules, with two granules transversely ronding and three warty protuberances; the frontal has two sharp teeth; the anterior lateral margin has nine sharp teeth, and the last teeth are long and spine-like, and protruding outward. Chelicerae stout, length longer than width of cephalothorax; long segments prismatic, male long segments more slender, anterior margin with 4 sharp spines.

2, green crab, an animal. Carapace is oval, body flat, hairless, cephalothorax is developed, both chelae are strong, hind feet, shaped like hokage, so it is called according to hokage. Cephalothoracic armor is about 1.5 times as wide as long, and the back is elevated and smooth. Surface of cephalothorax with obvious "H"-shaped indentation; forehead with 4 prominent triangular teeth, size and spacing of teeth roughly equal. Anterolateral margin with 9 prominent triangular teeth of similar size.

3, frog crab: cephalothorax is frog-shaped, larger than wide, the front 2/3 wide, the back 1/3 narrow, the back is very bulging, densely with scale-like spines. Frontal 3 teeth, the middle tooth is large and triangular, the lateral teeth are small.

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