Management of tadpole stage and metamorphosis stage of cultured forest frog

1. Feeding and management of tadpole period

The tadpole stage is a very important period in the individual life history of forest frog, which usually lasts 40-50 days. Artificial greenhouse is a good facility for raising tadpoles.

⑴ tadpole feeding: tadpoles are omnivorous, mainly feeding on algae, weeds, wild vegetables, vegetables, all kinds of animal meat and viscera and so on. Under the condition of artificial feeding, in order to cultivate high-quality young frogs, a certain amount of artificial feed should be fed as follows:

1-7 days old: mainly eat egg gelatin film, no artificial feed.

8-14 days old: eat plant feed, mainly soybean milk and cooked sheep's hoof leaves, mountain sesame and other tender leaves. Feed once a day, 250 grams per square meter.

15-29 days old: eat tender Tilia, elm leaves, sheep's hoof leaves, Artemisia grass, etc., combined with concentrate feed (corn meal: soybean cake meal: fish meal: bone and meat meal is 1-1-1-1-0. 5) or fish feed with the same nutritional value. The daily investment is 1 / 2, and the concentrate dosage is 500 / 1000 g / m2.

30 days old: stop eating during metamorphosis and stop using artificial feed.

The tadpole feed is mainly plant feed, and the ratio of concentrate to roughage is about 1:2. The feed can be directly put on the feeding board on the waterside of the breeding pond or in the water.

Management of ⑵ tadpole period:

① density adjustment. When the density of tadpoles in captivity is about 10 days old, 5000 tadpoles per square meter should be stocked; at 15-20 days old, the density should be controlled at 2500-3000 tadpoles per square meter; at 25-30 days old, 1500 million tadpoles should be stocked per square meter of water surface.

The principle of age consistency of tadpoles in the same pool of ②. When artificial breeding tadpoles, the density is high, which is easy to cause the phenomenon of cannibalism among tadpoles. Tadpoles do great harm to the later egg mass after feeding. They can quickly bite through the unhatched egg membrane, resulting in the death of a large number of eggs. Therefore, the eggs at the same time must be placed in the same incubation pool to ensure the same age of tadpoles in the same pool.

③ feeding. Tadpoles should be fed regularly and at a fixed point, and feed quality and quantity should be guaranteed at the same time. If the feed is insufficient, the tadpoles kill each other, usually the big ones bite the small ones, or a few tadpoles besiege a tadpole until they eat it. If the amount of material is excessive, the water quality will be seriously polluted, the dissolved oxygen in the pool water will be reduced, and a large number of tadpoles will die.

④ pool water management. The key point of pool water management in tadpole period, its main content can be summarized as "water quality, water quantity and water temperature".

During the tadpole period, it is necessary to ensure adequate water supply and drainage and irrigation at any time. The water surface of the pool should be stable and the water injection should be gentle. In the early stage of tadpole growth, the water temperature is regulated by irrigation at 14: 15 every afternoon. Generally, shallow water should be irrigated during the day and sunny days, and deep irrigation at night or rainy days. In the later stage of tadpole growth, when the water temperature reaches more than 24 ℃, the amount of irrigation should be increased to reduce the water temperature.

In addition, it is necessary to often check the water level in the pond, clean up the sediment in time, ensure that the breeding pond has continuous water and no smelly water, and strictly prevent the pollution of sewage and pesticides. The pH value of pool water should be 6.5-7.0. Change the pool water thoroughly once a week.

two。 Management of metamorphosis

When the tadpole reaches the age of 25-29 days, the tadpole has a total length of 4.3-1.5 cm, a body length of 1.2-1.5 cm, an oblate shape, a diameter of 0.9-1.5 cm, a tail length of 3.2-3.5 cm, and a basically intact hindleg with a length of 1-1.5 cm. Two small protuberances emerge at the foreleg and begin to transition to metamorphosis. Tadpoles enter metamorphosis is characterized by protuberances in the forelimbs on the side of the body, abdominal contraction and thinning, smaller body size and cessation of eating.

When the tadpoles develop to the metamorphosis stage, if there is a reservoir in the feeding circle of young frogs (covering an area of 2 to 4 square meters), the tadpoles in the metamorphosis stage can be directly fished and transferred to the reservoir in the breeding circle, so that they can be metamorphosed naturally and raised directly in the circle.

If there is no reservoir in the feeding circle, it is necessary to wait for the young frogs to be metamorphosed, and then catch them and send them to the breeding circle in time. It is best to use your hands to control the net instead of directly using your hands to avoid damaging the young frogs.

Before the tadpole metamorphosis comes, plastic sheeting should be selected to surround the metamorphosis pool, and the fence should be tight and seamless to prevent the young frogs from escaping.

During the metamorphosis of tadpoles, some birds should be prevented from pecking.