Identification of eel seedling varieties

At present, it is the Yangtze River eel seedling flood season, Jiangsu, Zhejiang, Anhui, Fujian, Shandong and other provinces and cities fishing vessels gathered in the Yangtze River Estuary fishing. Because the eel seedlings produced in the Yangtze River are "Japanese eels", it is better than "European eels" produced in France, "American eels" produced in the United States, "Australian eels" produced in Indonesia and Australia and "Filipino eels" produced in the Philippines. There is not only obvious difference in price, but also suitable for breeding in our country. In order to avoid being deceived by farmers in buying eel seedlings, the characteristics and identification methods of all kinds of eel seedlings are introduced as follows:

First, the Japanese eel seedling is long fin type, the whole body is transparent, the body is round, there are no melanin cells on the tail stalk, the eyes are small, the snout is long and long; the European eel seedling is also long fin type, round body, about 250% of the individuals have star-shaped melanocysts on the tail stalk than the Japanese eel, there is a red line along the vertebra leading to the tail, the eyes are big and the kiss is short, and the abdomen will glow when the light irradiates at night; the American eel is short and its eyes protrude and small. Others are the same as Japanese eels; Australian eels are smaller. The head is slightly blunt and there are stellate black spots on the tail. The vertebrae were 7 ~ 9 (107 ~ 110) less than that of Japanese eel, and there were stellate melanocytic cells on the tail stalk of Philippine eel, and the others were the same as Japanese eel.

Second, look at the activities of the Japanese eel in the palm of the hand, that is, it quickly makes left and right, bends and beats up and down, and soon gathers around to eat. When it grows to about 2 grams, a melanin ring appears at the end of the tail handle; the European eel can only bend the left and right planes in the palm and move its head upward like a snake. Eating Japanese eel is not as dynamic as Japanese eel, slow growth, afraid of heat, easy to die above 27 ℃; American eel is similar to Japanese eel; Australian eel has strong eating ability, like grass carp, easy to bulge to death, and the survival rate is low; Philippine eel is a large individual, so China has not yet carried out culture.

Third, the reaction in butene solution will not kill Japanese eel in 0.4ppm butene solution for more than 1 hour. Other species of eel seedlings will die within an hour.