When to Stock River Snails? Keep These Precautions in Mind
The river snail family is not only a delicacy, but also serves as an irreplaceable animal-based bait with comprehensive nutritional value in river crab farming. It is not only a live bait that river crabs love to eat, but can also purify water quality and remove organic matter (humus) at the bottom of the pond. If a pond has none of us, then during the farming process, the difficulty of controlling water and controlling grass will increase! The possibility of raising large crabs will be very small! When are river snails generally stocked? What are theprecautions?How to select good river snails?
1. When are river snails generally stocked?
The first time, complete it before Qingming Festival, stocking 300 jin/mu. Putting river snails in before Qingming helps them accumulate nutrients, so that after Qingming they can begin to produce large numbers of offspring. After the crab seedlings grow a bit bigger, the river snails will be their best natural bait.
The second time, stock at the end of July and the beginning of August, with a stocking rate of 200 jin/mu, to provide high-quality natural bait for the crabs about to mature, which can play a role in promoting yellow and hastening paste.
In winter, it is better to stock thin-shelled small to medium mature snails that matured that year, because at Qingming they are the best seed source of spawning snails, and the young snails produced by the mature snails in the pond will also be the best opening feed for spring seedlings;
For spring snails, choose large ones. When snails are stocked after the beginning of spring, the snails have already begun to enter their growth period. The larger the individual, the more nutrients it contains, and it is the best live bait for crabs after the second molting. A sufficient supply of snails will be the basic guarantee for crab growth.
2. Precautions for stocking river snails
1. Do not stock too large an amount of river snails in the first batch; it should account for about 1/3 of the total annual stocking amount. If the stocking amount is too large, it can very easily lead to clear water in the early stage and difficulty in fertilizing the water; in severe cases, it may even cause an outbreak of cyanobacteria.
In winter, it is better to stock thin-shelled small to medium mature snails that matured that year, because at Qingming they are the best seed source of spawning snails, and the young snails produced by the mature snails in the pond will also be the best opening feed for spring seedlings; for spring snails, choose large ones. When snails are stocked after the beginning of spring, the snails have already begun to enter their growth period. The larger the individual, the more nutrients it contains, and it is the best live bait for crabs after the second molting. A sufficient supply of snails will be the basic guarantee for crab growth.
2. Choose river snails with as few empty shells and as little mud and dirt as possible, and at the same time try to avoid river snails carrying cyanobacteria into the pond; (2) the shell is relatively thin and breaks easily when stepped on; (3) it is best to choose manually caught ones with no damage to the shell, as the survival rate is relatively higher
3. On the second day after stocking river snails, disinfect promptly to prevent the introduction of harmful bacteria.
4. After stocking river snails, fertilize the water as appropriate according to the water quality conditions.
5. When stocking snails, try to avoid overcast, rainy and stuffy weather to prevent the snails from dying after stocking due to weather, temperature and other effects, leading to bottom spoilage and a low survival rate. In winter below 5 degrees C, stocking river snails will cause frostbite; in summer above 28 degrees C, river snails will die from lack of oxygen during transport, and being exposed to rain during transport can also easily cause snail death, and so on,
6. Because the temperature is relatively low in the early period and snails do not crawl easily, when stocking, care should be taken not to stock them in piles, to prevent oxygen deprivation and death caused by snails piling up.
7. Do a good job of detoxification before stocking to prevent river snails from climbing ashore after stocking or burrowing into the bottom mud, which in severe cases causes death and increases farming costs.
3. How to select river snails?
1. River snails are required to have complete shells with no damage.
2. When startled, the river snail can quickly retract into its shell, and at the same time the operculum can firmly close the shell opening.
3. There are no parasites such as leeches inside the river snail.
4. Check whether the tail of the river snail is damaged, to distinguish machine-caught river snails from hand-caught river snails.
Note: River snails live in water, so never let them be exposed to air for a long time. If left that way for more than 24 hours, some river snails will suffocate and die from lack of oxygen!