It belongs to the family Leucaenidae, commonly known as small whitebait.

2. Description of appearance:

The body is slender, slightly cylindrical at the front, flat at the rear, blunt, arc-shaped, transparent and toothless. The starting point of dorsal fin is less than the distance from the base of caudal fin to the base of pectoral fin. After leaving the water, the fish turns milky white and keeps cartilage for life, except that there are a row of scales on the upper side of the base of anal fin of male individuals when the gonads are mature. The lower jaw is slightly longer than the upper jaw. There are a row of sparse fine teeth on the upper and lower jaws, and there are no teeth on the mouth cover, and the tongue surface is smooth and toothless. There are a row of black dots along the ventral surface of the living body. The dorsal fin is 2, 12-14, which is close to the gluteal fin, the gluteal fin is 3, 22-24, the pectoral fin is 7, the starting point is closer to the snout than to the caudal fin base, the fat fin is small, the caudal thread is forked, and the spine pushes the bone 5-53.

3. Living environment:

The whitebait in Taihu Lake belongs to pure fresh water species, and has no strict requirements on water conditions. It likes to live in the upper layer of water with open water surface, high transparency and sufficient dissolved oxygen, and feeds on rotifers, cladocera and copepods in zooplankton. The breeding period is from March to July, and it lays eggs in the water-grass overgrown area near the lake. The individual is small, grows rapidly and has strong reproductive ability. It only takes about 6 months from hatching to growing into an adult. Distributed in the middle and lower reaches of the Yangtze River and affiliated lakes. The comparison of the growth of different waters in the same period shows that the growth of Yunnan is the fastest and the individual is the largest. There is little difference in the growth rate of lakes in the middle and lower reaches of the Yangtze River. Now, many places have breeding. After transplanting to new waters, as long as the water conditions are suitable, the population yield can often be explosively formed within one or two years, and the benefits are rapid and huge.

4. Breeding:

The whitebait in Taihu Lake has two spawning reproductive groups, and the parents die naturally after spawning. Because the hatched fry can mature and lay eggs within one year, its life span is also one year. It is divided into spring groups that spawn in spring and autumn groups that spawn in autumn. The growth rate of body length and weight of spring group is the highest in 1-2 months, followed by 2-3 months, and then decreases with the increase of months. Although the growth rate of autumn group is also the highest in January-February, it is far lower than that of spring group, and then it decreases, and then it increases in May-June and then decreases. The difference of growth rate between spring population and autumn population may be affected by three factors, namely population density, seasonal temperature and food biological adequacy.

The spawning population in spring is the main spawning population, with a body length ranging from 5. cm to 7. cm and a body weight ranging from .5 g to 1.5 g. The spawning period starts from mid-March to mid-May, and mid-April is the peak season. According to the investigation, spawning or immediate spawning parent fish can be caught in the whole Taihu Lake, but the relatively concentrated area is the bay area with a small number of submerged plants. Clear water or muddy water, rising or falling water, sunny or rainy days can spawn, but the lake wind is slight, and the spawning is more abundant at 3-4 pm on sunny days. Sinking eggs are non-sticky, and the minimum water temperature required for spawning is 13℃. The optimum water temperature for hatching fertilized eggs is 16℃-21℃, and the fertilized eggs can hatch larvae in about 1 hours. The number of eggs per female fish is 1,-2,, with an average of about 1,6. The smallest egg diameter is .6 mm, the largest is .73 mm, with an average of .66 mm. There are more males than females in the spawning population, which can be one to several times more.

In autumn, the spawning colony is 5.1-6.3cm long and .86-1.28g in weight. The spawning season starts from late September to late October, and lasts only over a month. The number of eggs per male fish is 1,-2,, with an average of 1,3 eggs. The water temperature requirement is higher than that in spring, with a minimum of 18℃ and a maximum of 23. The optimum temperature for embryo development of fertilized eggs is 16℃-21℃. In this temperature range, fertilized eggs can hatch larvae in about 1 hours, and when the water temperature is lower than the optimum temperature range, the development speed slows down. Under the condition of 5.5℃-12℃, the hatching time of embryos can last until 236.5 hours, but they can still hatch normally.

5. "Taihu brand" whitebait:

Taihu whitebait, mackerel and white shrimp are also called "three treasures of Taihu Lake". Whitebait, commonly known as noodle or noodle stick fish, is slender, slightly round and shaped like a Hosta. It is tender and transparent, soft and boneless, without intestines, white and without scales, and its color is like silver. The whitebait in Taihu Lake is the best of the four species of whitebait in Taihu Lake (big whitebait, Leishi whitebait, short whitebait and short whitebait with few teeth).

delicious, processed and frozen, or dried fish sell well at home and abroad. "Taihu brand" chilled whitebait enjoys a long-standing reputation in Japan and Southeast Asian countries. Whitebait can also be made into dried whitebait by exposure, and its color, fragrance, taste and shape remain unchanged for a long time. Whitebait is rich in nutrition and is called fish ginseng in Japan. Whitebait is tender and delicious, and can be used to make all kinds of fine dishes. Scrambled eggs with whitebait, delicious and tender, is a traditional restaurant and family food; Dry fried whitebait is crispy outside and tender inside, golden in color, crisp and delicious. Using whitebait to make soup is even more fragrant and refreshing, delicious and delicious. In addition, whitebait balls, hibiscus whitebait, whitebait spring rolls and whitebait wonton are all famous dishes in Taihu Lake with unique flavor.

6. whitebait incident in Taihu Lake:

In October p>8, whitebait in Taihu Lake was found to contain a large amount of formaldehyde for the first time after sampling and testing. Vendors soak whitebait in high-concentration formaldehyde solution for preservation and white color, and leave it for too long.

according to article 9 of the food hygiene law of the people's Republic of China, the production and marketing of food containing formaldehyde are prohibited. Formaldehyde is a colorless, irritating gas, easily soluble in water, and its aqueous solution is commonly known as "formalin", which has the functions of anticorrosion and freshness preservation. Aquatic products soaked in formaldehyde are too white in color, tough in hand and hard in taste. If the amount of formaldehyde is too large, it will be irritating when chewed. Long-term consumption of food containing formaldehyde is harmful to human health. If you are satisfied, please adopt it. If you don't understand it, please ask, clap and help each other.