Brief introduction of African giant snail (scientific name: Frica Martina). Agate mule family, belonging to African snail genus. Adult African giant snails are usually 7~8cm long, and the largest can reach 20cm. The largest recorded specimen is 39.3cm, which may not be intuitive for me to say. A person's face is about 20 centimeters long. Now you know how big it is. Widespread fear! As a gastropod, its life span is also very long, usually 5-6 years, and the longest can reach 9 years, which is relatively long among gastropods. It stays during the day and comes out at night, preferring yin to yang. The suitable growth temperature is 15~38℃ and the soil humidity is 45%~85%.
Good prenatal and postnatal care, rapid growth.
African giant snails have amazing reproductive ability, hermaphroditism and hybrid reproduction. So when any two snails meet, they will mate. More importantly, however, its reproduction can be self-regulated according to the environment. It can store allogenic semen and keep it in the body for months until the environment is suitable for laying eggs. If the conditions are not good, then wait for regeneration, adhere to "prenatal and postnatal care" and ensure the living environment of the next generation. After 5~ 15 months, the next generation can change from young eggs to mature eggs; Why is the span so long? This is another feature of it. It can grow rapidly in the right environment and at the right temperature. Adult African snails can breed four times a year in a suitable environment, and can lay eggs 150~300 at a time.
Let's do a math problem to prove its amazing reproductive ability: If Xiaoming has a pair of healthy African snails, how many years will it take for Xiaoming to achieve Wang Jianlin's goal of 100 million according to the standard of Dink's probability of 20%, 200 eggs at a time and 6 months for maturity under suitable environment?
If the calculation is wrong, no rebuttal is accepted.
According to the above table, the small target of 1 100 million will be achieved within two years, and there are more than 8 billion potential stocks!
Self-protection mechanism of seeking advantages and avoiding disadvantages
In addition to being fertile, African snails are also tenacious. When the living environment is not suitable, they will close the door, secrete a wax-like thing at the mouth of the shell, seal the mouth of the shell and stay in it for several months. When the rainy season comes, it will break through the wax seal and continue its activities.
Many teeth and a good appetite.
African giant snails are omnivores with 25,000 teeth, which can harm more than 500 kinds of crops. In Southeast Asia, coconut, cocoa and rubber plantations are their targets. When they are hungry, they can even eat their companions' bodies, papers and so on. The most powerful thing is that they can eat cement, supplement calcium and promote the development of shells.
Why don't you touch it? Don't eat it, because it is the intermediate host of parasites and pathogenic bacteria, which will bring various diseases to human beings. For example, Angiostrongylus cantonensis, a blood-borne nematode in Guangzhou, is the normal host of this parasite, which may be carried by the feces of mice, while the habitat of African giant snails is very close to that of mice, so it is easy to carry this parasite. Angiostrongylus cantonensis can cause various neurological problems, such as eosinophilic meningitis. There is also mycobacterium tuberculosis, which will directly lead to tuberculosis. Moreover, it is not only eating that will cause the spread of these parasites. Scientists have found that this parasite and pathogen can also be found in the living environment of African snails.
Invasion case
Because of the above characteristics, African snail is defined as an alien invasive species, and it is recognized as the worst snail in tropical and subtropical regions. The United States, in particular, spends a lot of manpower and financial resources to eliminate it every year, but the effect is limited. Every rainy season, they will erupt again. The invasion of American snails began with 1966. A little boy brought three snails back to Miami from Hawaii. Seven years later, they formed a huge local group of 17000. However, compared with the above-mentioned small target of 1 100 million, there is still a certain gap between the theoretical value and the actual value. #).
However, in Ghana, East Africa, African snails are very popular because eating snails has become a local food culture. Ghana claims to eat 65,438+0,000 tons of African snails every year. The local snails are endangered because they are eaten in large quantities.
The earliest invasion case in China was in 1932, when a Japanese university professor in Taipei introduced African snails from Singapore to Taiwan Province Province for food. Later it appeared in Guangdong, Fujian, Guangxi and other provinces. Fortunately, African snails have not caused serious species invasion in China, so China has not taken some effective and active measures to eliminate them for the time being.
At the end of two centuries, African snails only lived in the coastal areas of Africa, but now they can be seen all over the world. The culprit of all this is human beings. As the top of the food chain, human beings should always be vigilant in front of nature, and never open nature's Pandora's box to satisfy temporary curiosity. Novel coronavirus, SARS and other events are vividly in my mind.