Procambarus clarkii pronounced làlàgǔ.

Procambarus clarkii is an arthropod of the genus Procambarus clarkii in the suborder Procambarus clarkii of the order Decapoda, and is commonly known as the freshwater crayfish. It is also known as the freshwater lobster because of its similarity in form to the lobster that lives in the ocean. Body color light brown or date red, small body size, male body less than 15 cm, weight 5-20 grams.

The carapace is divided into cephalothorax and abdomen; cephalothorax is large, covered with thick crustaceans; head is triangular; thoracic footsteps 5 pairs, the first pair of footsteps thick crab-chela-like, the second and third pair of footsteps small, the front end of the limbs near chelipeds, the fourth and fifth pairs of footsteps clawed end; abdominal segmentation is obvious, was cylindrical.

Procambarus clarkii (Procambarus clarkii) is only found in northeastern China, Japan, and South Korea, and inhabits mountain streams and rivers. They like to hide in the rocky crevices of rivers at a depth of 20-30 centimeters; they have strong phototropism and are more active at night than during the day. It prefers dark light and is drought-resistant, and can survive for a short period of time when rivers dry up.

Mixed diet, strong hunger, decaying plants, algae, aquatic insects and small crustaceans can be used as its food, but also eat decaying animal carcasses and organic debris and microorganisms. Sensitive to oxygen in the water, do not hibernate, winter activities as usual. 9-10 months of mating, the following spring began to lay eggs, hatched in mid- to late May to become larvae.

Morphological Characteristics

Northeast freshwater crayfish (Procambarus clarkii) is the largest; North Korean freshwater crayfish (Procambarus clarkii) and northeast freshwater crayfish (Procambarus clarkii) are very similar, but the body size is smaller, the frontal area is wider and flat, the lateral plate of the abdominal segments are rounded; Xulang freshwater crayfish (Procambarus clarkii) is the smallest, in the cephalothorax, behind the nuchal groove of the armored neck, left and right, each with one side of the spine, the frontal area more elevated, which is the characteristic of it.

North-eastern freshwater crayfish mayfly carapace is thicker, body color has reddish brown, dark dark brown, yellowish brown, olive green, etc., mostly yellowish brown. The cephalothorax is thick and cylindrical, with hard, smooth cephalothoracic armor, accounting for nearly 1/2 of the body length. Northeast freshwater crayfish dorsal center of the cervical groove is relatively straight, the thorax has two shallower than the cervical groove of the left and right symmetrical segmentation marks.