Why should shrimp be shelled?

The shelling process of shrimp is regulated by hormones.

The first is molting inhibitory hormone, which can inhibit the accumulation of nutrients and calcium and delay molting activities.

The second is the hormone promoting shelling, which is a hormone that has an influence on the early stage of shelling and can promote various physiological activities in the early stage of shelling. For example, inorganic salts and organic substances in the old shell are reabsorbed, which makes the old shell soft and thin, especially some sewing parts soft and thin and easy to crack, which is conducive to the smooth shelling activities. The substances in the old shell can be reabsorbed, so that the blood calcium in the body is obviously increased, and the contents of organic phosphorus and other substances are also increased. These hormones are mainly regulated by the central nervous system.

The third kind is the hormone that regulates water absorption during hulling, which can regulate water absorption, so that the water absorption of shrimp can be reasonably increased before and after hulling, and the new shell can be rapidly expanded and strengthened.

Because shrimp shells are not like animal skin.

Its shell will not grow with the growth of the body.

So every once in a while, there will be new shells, and the new shells will be bigger.

Then the old shell is taken off and the body can grow up. So do snakes.

Extended data

The shrimps and crabs mentioned above are all arthropods, and they all need to go through a growth process before they can shell and grow again. Usually, shrimps and crabs prove that they are one year old every time they shell, so arthropods can't avoid the process of shelling. When the shell is found, the children at home can just take it out and throw it away. Don't worry about what will happen to the shelled shrimp in the future. The question of whether you can still feed will be alive and kicking in a few days.

Shrimp can be divided into seawater shrimp and freshwater shrimp according to different producing areas. Sea shrimp is also called red shrimp, including lobster and prawn. Among them, prawn tastes the most beautiful, is the best in food and is a famous seafood product. The common European shrimp in the North Atlantic is about 8 cm (3_) long, gray or dark brown with brown or red spots. Penaeus monodon is distributed along the coast from North Carolina to Mexico. Length18cm (7 _); Larvae live in shallow bay, and then enter the deep sea, eating small animals and plants. The above two species have important economic value with brown ditch shrimp and pink ditch shrimp. Crangonfranciscorum is a kind of prawn in the Pacific Ocean. Freshwater shrimps, such as Charybridae, mainly live in warm areas, and some are in brackish water; Some are as long as 20 cm (8_). Ataephyradesmarestii is 1, 6 ~ 2,7 cm (0,6 ~1,1_), which is distributed in fresh water areas of Europe, North Africa and the Near East and lives in groups among aquatic plants. Syncaris (2 ~ 5 cm long [1~ 2 _]) and Palaemoniasganteri (half as long as the former, only found in Mammoth Cave in Kentucky, USA) are famous freshwater prawns in North America. Swordtail fish is a freshwater fish distributed in the West Indies. Macrobrachium or gibbon is edible and mainly distributed in tropical areas. Alpheus can grow to 3,5cm (1, 4 _).

shrimp

Knock the prey unconscious with big claws. Red sea drum shrimp and tiger fish live in the same cave, and the fish sends danger signals to the shrimp through physical movement. Tropical shrimp (Stenopushispidus) is 3. 5cm (1, 4_) long. Coral fish swims upside down from its claws, and shrimp cleans the scales for it. Fairy shrimp is similar in shape to shrimp, but belongs to Anostraca. Transparent is the shrimp that has just grown.

China has a vast sea area, many rivers and lakes, and is rich in sea shrimp and freshwater shrimp. Shrimp is delicious and nutritious, and can be used to make all kinds of delicious food. It has the reputation of "licorice" in dishes. There are Antarctic red shrimp, prawn, prawn, Neoprawn, anglerfish, lobster and so on. Green shrimp includes green shrimp, river shrimp, grass shrimp and so on. There are salted shrimps such as white shrimps.

breeding technology

Select seeds

Select 100 prawns with strong physique, no disease or injury, specifications of 20-50g and sex ratio of 1: 1 as parent prawns, and feed the selected parent prawns into a 6×8×l meter cement pond, which is covered with glass fiber reinforced plastic tiles and a heating system, and the weight of prawns in the pond is1every day. Red crayfish is bright red on the outside of the front, and its claws are longer than its body length; The claws of female shrimp are basically blue, and the length is less than the body length. The reproductive process of mature male shrimp is obviously rod-shaped at the base of the fifth foot; The reproductive pore of female shrimp is open at the base of the third foot. Put some cleaned and disinfected nets in the parent shrimp pond as the hidden objects of the parent shrimp, suck dirt and change water every day, and keep the light at12i:12d (12h light,12h dark).

lay eggs

In late April, the parent shrimps began to mate and lay eggs. The mating of red crayfish is soft shell mating. Before mating, the female shrimps should undergo reproductive molting, and the female shrimps begin to lay eggs within 12 hours after the male shrimps produce sperm. The eggs laid by the female shrimp are dark yellow after fertilization and attach to the empty stomach formed by the inward curling of the abdominal foot and tail fan. A shrimp with eggs weighing 48 grams has 326 eggs, a shrimp with high eggs has 44 1 egg, and a shrimp with low eggs has only 27 eggs.

embryonic development

The fertilized eggs of red crayfish are dark yellow, and gradually turn yellow-orange, red-orange and light gray with the development of embryos. The eggs of Procambarus clarkii were divided into four groups for comparative experiment of embryo development. The results showed that the embryo development of Procambarus clarkii eggs was extremely slow at 65438 09℃. When the temperature is 2 1 ~ 23℃, the incubation time is 4 1 day, and the young shrimp leave the mother body within 80 days. At 26℃, fertilized eggs hatch out of the membrane in 30 days, and young shrimps leave the mother body in 52 days. At 29 ~ 30℃, the membrane hatched within 25 days and separated from the mother body within 40 days.

Larval culture

Larvae of red crayfish are hatched and collected, and then put into a soil pond for feeding. In the early stage of growth, larvae mainly feed on organic debris and unicellular algae such as Chlorella. Whether the water is rich in organic debris and unicellular algae is very important to improve the survival rate of crayfish larvae. If the amount of bait is insufficient, they will kill each other. Through the anatomy of the young shrimp, it was found that there were basically no zooplankton remains such as cladocera and copepod in the stomach of the young shrimp, which was the main reason for the poor fluidity of the young shrimp and the difficulty in obtaining zooplankton. After 7 weeks of rearing, the average length of larvae can reach 7.6 cm. 5. The latest scientific methods to improve the nutritional value and yield of shrimp. If the content of astaxanthin (also called astaxanthin in Chinese) in shrimp culture is strengthened, that is, the astaxanthin content is added to the feed in proportion, that is, 2,0% astaxanthin algae powder is added in proportion, the following verified effects will be achieved (see further reading for details):

Young shrimp: 0.4 ~ 0.8 kg per ton of feed (survival rate increased by 50%). Time of use: the whole breeding period.

Adult shrimp: 0.24 kg per ton of feed (survival rate increased by 45%, shrimp disease decreased obviously) Use time: 2 months before fishing.

Shrimp yield: 0,75 ~10,5 per ton of feed (spawning amount increased by 40%). Use time: 2 months before spawning.