The first thing to keep hydra is to prepare a fish tank. The bigger the better. So we can see how it hunts secretly. If the fish tank is too small, its range of activities is not large and it has no observation value.
Next, spread a layer of fine sand on the fish tank. Don't put pond mud or river mud. Wash the sand repeatedly until it becomes clear when you stir it by hand. About 10 times is enough. In this way, when you change water or plant grass, it will not cause turbidity in the fish tank and affect your vision. Then plant some aquatic plants such as snapdragon. It is convenient for hydra to inhabit. Don't forget to fix a wooden stick in the fish tank so that Hydra can climb out when it comes to the surface. The rest is to prepare hydra, preferably a female and a male, of the same size. Females have a basic spawning period near the lower abdomen, while males do not. It is a hydra with wings and buds. In other words, it will be feathered in half a year or a year. There are three reasons. First, it is easy to feed. Second: after a period of time, you can personally observe the symptoms before and the process of emergence. Third: large size and wide predation range. It's easy for you to help it find food.
After the above preparations, it is necessary to prepare food for it: it can be shrimp, tadpoles, other aquatic insects and river snail (small) fish. Anyway, it has a wide range of activities. Don't put lice and water mantis, or they will eat them. So you can watch its covert pursuit and hunting. Anything smaller than it will do. It also eats smaller ones, so don't let them go. I don't like autocorrelation residuals.
Then you can observe. Remember to clean up the leftover animal carcasses in time. Or it will stink. They can even hunt at night without lights. During the day, they rely on vision. At night, they are dormant, relying on the vibration generated by their prey swimming in the water, and the success rate is also very high.
Note: Some families spray pesticides in summer. You can't let the water in the fish tank become a little bit. Even a little will pollute the whole fish tank and kill it. I have learned my lesson. ) If you want to spray, cover it in advance. Don't open it until the smell has dispersed a lot. Spread a layer of river mud in winter and let it go in for the winter. It should be buried before winter comes.
When its wing buds thicken, it is not far from eclosion. Some even reflect the body color of adults. When you find that it often climbs on a stick and sticks its head out of the water, it proves that it will grow feathers in a few days. But the emergence of seedlings is usually 3-4 am, and you can see it when you get up early. If it rained that day, they wouldn't feather. Because the rain will make it impossible to spread its wings. All right. The rest is up to you to observe and explore.
Question 2: What do dragonfly larvae eat? Dragonfly larvae living in streams mainly feed on Diptera larvae (such as Mayfly larvae, stonefly larvae and Chironomid larvae) and some small fish, while species living in still water mainly feed on Diptera larvae (such as tadpoles, shrimps, small fish, water fleas, smaller Odonata larvae, backstroke piles, dragonflies and Chironomid larvae).
Question 3: What do dragonflies eat? Dragonflies are beneficial insects. They are almost born to catch pests, which is of great help to human life, not only beneficial to people's health, but also plays a great role in the high yield of farmland crops.
Dragonflies also have an amazing appetite. It belongs to carnivorous insects and feeds on small insects such as mosquitoes and flies. A big green dragonfly, commonly known as "Qingtouleng", can eat about 2,000 aphids and other small flying insects a day. Of course, it eats mosquitoes, flies and the like. In addition, it welcomes all flying and crawling moths and insects. In this way, a large number of pests have been eliminated for human beings, and it is well-deserved to call them "beneficial insects".
Question 4: What do dragonflies eat? Dragonflies are beneficial insects. They are almost born to catch pests, which is of great help to human life, not only to human health, but also to the high yield of farmland crops.
Dragonflies also have an amazing appetite. It belongs to carnivorous insects and feeds on small insects such as mosquitoes and flies. A big green dragonfly, commonly known as "Qingtouleng", can eat about 2,000 aphids and other small flying insects a day. Of course, it eats mosquitoes, flies and the like. In addition, it welcomes all flying and crawling moths and insects. In this way, a large number of pests have been eliminated for human beings, and it is well-deserved to call them "beneficial insects".
Question 5: What do young eggs of water dragonflies eat? Tadpoles, shrimp, small fish, Daphnia, smaller larvae of Odonata, backstroke piles, swallowtails (mosquito larvae), red worms, etc. The cycle of the dragonfly larva hydra varies according to different species, ranging from 2-3 months to 65,438+0-3 years for ordinary species.