Why is the snail's shell added by itself?

Snails have shells from hatching, which are very important to snails, such as avoiding danger and protecting internal organs. Snails cannot survive without shells.

Snails:

Snails belong to Amphibia, Amphibia, and Megasnail family.

first, the external characteristics of snails

The shell is low conical, right-handed or left-handed. The head is prominent, with two pairs of antennae, and the latter pair has eyes at the top. There are flat and wide abdominal feet on the ventral surface.

Second, the living habits of snails

1. They like dark, humid and hidden environments, and they are sensitive to strong light stimulation.

2. I like to crawl into loose humus soil to inhabit, lay eggs, adjust the humidity in my body and absorb some nutrients for up to 12 hours.

3. omnivorous and partial eclipse coexist.

4. I like humidity and fear flooding. Snails have an active appetite on wet nights when they are fed with wet food. But flooding can suffocate snails.

5. Self-sufficiency. As soon as the baby snail hatches, it will crawl and feed, without the care of its mother. When invaded by enemy, its head and feet retract into the shell and secrete mucus to seal the shell mouth; When the shell is damaged and disabled, it can secrete some substances to repair the body and the external body.

6. Strong patience. Snails have amazing survival ability and strong tolerance to cold, heat, hunger and drought.

7. I like constant temperature culture. The temperature is constant between 25 ~ 28℃, and the growth, development and reproduction are vigorous.

Third, the reproductive characteristics of snails

1. Snails are hermaphroditic, interbreeding, and both sexes lay eggs. The snail itself is both a father and a mother. Two snails cooperate with each other, and both sides repeatedly stimulate each other's reproductive holes with their love arrows (penises). After intense stabbing, both penises are inserted into each other's vaginas to ejaculate. After 1 days of conception, both parties can lay eggs, and after 8 days, the eggs can hatch into small snails.

2. Long mating time, slow spawning speed and high degree of difficulty. The mating time of oestrus snails is as long as 2 ~ 3 hours at a time, and some of them are as long as 6 hours or more. Snails can lay 2 eggs per minute, and each spawning time is as long as 1 ~ 2 hours, and some of them are more than 3 hours. Snails often die due to poor feeding, collapse and dystocia during spawning. Some of them died in dystocia, accounting for about 3% of the total number of snails.

3. The reproductive rate is high. Each snail can lay eggs 6-7 times a year, with an average of 2 eggs each time. Snails weighing 35 grams can lay 12 eggs each time, and snails weighing 4-5 grams can lay 15-18 eggs each time; Snails weighing 6-1g can lay 3-4 eggs at a time.

4. The reproduction of snails is not limited by age. Under the same suitable reproductive conditions, the bigger the snail, the more eggs it lays.

5. Short service life. The life span of snails is generally 5-6 years. Under uncomfortable living conditions, it will accelerate the death of snails and shorten their life span.

6. three slow, two fast, one more difficult. Three slowness means slow action, slow mating and slow spawning; Second, fast growth and fast shell shrinkage; One difficulty and more eggs are difficult to lay eggs and more eggs.

slug:

the scientific name of slug is Agriolimax agrestis (Linnaeus), which belongs to Gastropoda, Cladocera, slug family. It is also known as the snail, slug, snail, etc. Distributed in southwest China, Yangtze River valley, Guangdong, Guangxi, Fujian, Jiangsu, Henan, Anhui and other places. Annual 2-6 generations. Hermaphroditism, allofertilization or syngamy reproduction, spawning more than 4 eggs, eggs piled in wet soil, egg stage 1-17 days, larval stage 55 days. The occurrence in spring and autumn is very harmful. April-June is the worst, and the Yangtze River basin is the worst in May-July. Wild slugs move at night and lurk during the day, and their hunger tolerance can last for more than 13 days. Moreover, this insect is a pest that harms crops, especially wheat seedlings, and it costs an average of $3 million a year to destroy them abroad.

A joke:

After the snail and the slug failed in dating, the snail said to everyone, "That boy is so poor that he can't even afford a house, and he dares to go out and pick up girls! Cut! " This word reached the slug's ear, and the slug angrily scolded, "Bah, I bought a house and I won't show it off with her back every day!" Virtue! "