The living habits and morphological characteristics of the white catfish (Northern six-bearded catfi

Silurus soldatovi belongs to the order Silurus soldatovi, the family Silurus, and the genus Silurus. Commonly known as: huaitouyu, huaizi, and six-bearded catfish. English name: Northem sheepfish.

Endangerment level: Vulnerable.

The body is long and the tail is flattened on both sides of the head. The head is long and flat. The muzzle is blunt and round. The mouth is large and sub-superior, with the upper jaw shorter than the lower jaw and extending beyond the back edge of the eyes; the jaw teeth are exposed; the upper and lower jaws and vomer all have pointed denticles. There are 3 pairs of barbels; 1 pair of maxillary barbels, extending to the pectoral fins; 2 pairs of mandibular barbels, with the front barbels being longer than the rear barbels. The eyes are small and positioned upward. The body has no scales. The dorsal fin is small and has no spines; the pectoral fin spines are weak, with smooth front and rear edges, extending to the pelvic fin; the pelvic fin is located behind the base of the dorsal fin and extends to the anal fin; the anal fin base is long, with 83-90 anal fin rays, slightly connected to the caudal fin; the caudal fin is rounded and truncated. The dorsal side of the body is light yellowish gray, and the ventral side is lighter.

It likes to live in main rivers and tributaries, but does not like to live in lake areas and flooded areas. They are middle and lower layer fish. They are not very active. They mostly inhabit the bottom of water bodies during the day and swim to shallow water to look for food at night. After autumn, they live in deep water or overwinter in sludge. Feeding intensity decreases in winter. It is a ferocious carnivorous fish that feeds on fish and other aquatic animals. The age of sexual maturity is 3 winter years or older. The growth rate is fast, and the body length can reach about 560-580 mm in the second winter and 675-685 mm in the third winter. According to records, the largest individual body is 2 meters long and weighs 40 kilograms.

It is mainly distributed in the Heilongjiang water system from Heihe City to Fuyuan County, Songhua River, Nenjiang River and Ussuri River, etc. It is also produced in the lower reaches of Liaohe River; it gradually decreases below the Russian Communist Youth League City.

In the past, it was more common in the plain areas of the middle reaches of Heilongjiang, and was often mixed with catfish. Since the 1950s, due to overfishing, the amount of natural replenishment is far less than the fishing amount; secondly, the sharp decline of water source forests in mountainous areas has caused a sharp decrease in the regular flow of the river (especially in the dry season); during the flood period, the muddy water increased sharply, and the average Harmful to fish resources; moreover, the discharge of toxic industrial sewage poses a threat to fish resources. After the 1960s, the catfish has almost disappeared in the Qiqihar section of the Nenjiang River.

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