Breeding techniques of cultured forest frog

The reproduction technology of forest frog is a main link in production, and the level of reproduction technology is directly related to the benefit of artificial breeding forest frog. The breeding technology of closed ditch frog mainly includes seed selection, spawning, hatching and feeding and so on.

Breeding eggs and frogs

At present, frog production is mainly based on breeding eggs, supplemented by breeding frogs, mostly collected in the wild, one is self-catching (picking), the other is buying. 1. Egg collection and transportation, spring egg collection, time-saving, labor-saving, low cost, is a common method adopted by farmers at present, in natural blisters, swamp water and other still water areas to use net fishing for egg masses, in principle, the earlier the better. The newly laid eggs are small in size, flexible, not easy to spread and easy to transport, because the peak of oviposition of forest frogs is at 5: 00 am, so the best time to collect frog eggs is 6: 00 am. Buckets are available for transporting eggs. Frog eggs that have been transported or laid for a long time should be sprinkled with a small amount of water to avoid adhesion of eggs to each other.

two。 Collection, transportation and selection of breeding frogs 1. Spring collection. Forest frogs usually leave the river from the beginning of April to the middle of April, and from the middle of April to the end of April, the water temperature begins to lay eggs at 10 ℃. Therefore, frogs should be collected in spring and caught in rivers, swamps, or natural bubbles in the wild.

two。 Collection in autumn. The period from mid-September to mid-October is the time for forest frogs to go down the mountain and into the river, during which a large number of frogs can be caught. Frogs should be caught by net, hand and urn, and drug catch and electric shock are strictly prohibited.

3. Bribe. At present, many frog farmers adopt the method of buying eggs and frogs, which is an important way to solve the provenance and can supplement the deficiency of self-catching. however, it should be noted that when buying breeding frogs in spring, the female frogs after ovulation should be prepared to lay eggs the following year, so the effect is not very good because of the low recapture rate.

4. The transportation of growing frogs. No matter what method you get, you should avoid damage. the frogs must be packed in sacks or baskets, and must not be pierced through the eyes, nostrils, upper and lower foreheads with rope, wire, etc., and should be packed in cage baskets during long-distance transportation. cover the cage with straw and often sprinkle water to maintain humidity; rinse with clean river water midway to avoid death caused by frog drying. There is no need to carry water when transporting frogs. When transporting in spring, it is necessary to have a good time for transportation, and it is not possible to transport over a long distance. if it lasts for more than 6 days, the breeding frogs will ovulate unfertilized eggs without "hugging".

5. The selection of frogs. At present, there is no selection standard for breeding frogs. According to the growth cycle and practical experience of forest frogs in recent years, frogs should choose 4-year-old frogs with a strong physique, a body weight of about 50 grams, and a better body color standard, namely dark brown.

Spawning method

The artificial spawning ground is quite different from the natural spawning ground, and the density of artificial breeding frogs is high, and forest frogs do not want to lay eggs in the spawning ground, so they must be forced to lay eggs in the spawning ground under artificial control. the methods of spawning can be cage spawning and ring spawning.

1. Cage spawning. Weave a cage with thin wire or branches, put the good breeding frogs into them according to the ratio of male and female at 1:1, then put the cage into the spawning pond, and properly adjust the depth of the water to keep the water depth in the cage at about 15 cm. The spawning cage should be placed in the still water area, away from the outlet and inlet. After breeding frogs are paired, when the water temperature is about 10 ℃, 7 Mel can lay eggs in 8 hours. We should pay attention to accurately grasp the time, transfer the frog eggs to the hatching pool in time, and take out the breeding frogs after spawning and send them to the dormancy ground. If the spawning pool, hatching pool and feeding pool are built according to a unified standard, several pools in the middle and upper reaches can be selected as spawning pools.

two。 Ring spawning. Surround the spawning pool with plastic film or barbed wire. The plastic film or barbed wire net is 1.5 meters high, tilted inward at an angle of 45 cents and 60 degrees, or folded inward into a right angle at the upper end, and compacted with soil at the lower end. According to the ratio of 1:1 between male and female, it is appropriate to put the breeding frog at a density of 10 per square meter of 15 pairs. In order to improve the pairing speed, about 10% of male frogs can be added, and egg clusters and breeding frogs should also be transferred in time after spawning. If the spawning pool, incubator and breeding pond are built according to a unified standard, the entire breeding farm can be surrounded and easy to manage. It is extremely convenient and feasible.

Third, hatching methods

Practice has proved that it is better to use natural incubation method. Natural hatching means that frog eggs are hatched by natural water temperature, which is basically similar to the hatching method of natural wild frogs, that is, eggs are hatched in a quantity of 15 clumps per square meter and allowed to hatch and grow naturally. Several problems should be paid attention to in the process of hatching: first, when hatching, the egg mass should be placed in the shallow water area, and then moved to the deep water area after the egg mass expands. If the egg mass is directly placed in the deep water area, because the egg mass is not expanded, the buoyancy is small and easy to sink to the bottom, and it is polluted. In addition, the water temperature in the deep water area is low, the hatching speed is slow, and the frog eggs are easy to be damaged and wasted. Second, in the initial stage of hatching, the same side water intake, effluent and closed (semi-closed) irrigation should be adopted to maintain the stability of the water surface and the temperature of the water. The water depth in the pool is about 20cm-30cm and should be covered at night because of the low temperature. Third, we should pay attention to prevent the egg mass from being contaminated by sludge. Artemisia straw, branches, etc. are built into small squares on the surface of the pool to control the eggs in a certain area to avoid floating to the edge of the pool to be contaminated. Fourth, we should pay attention to preventing natural enemies and expel poultry, especially natural enemies such as ducks and frogs. Fifth, pay attention to keep the environment quiet during the incubation period, avoid vibrating pool ridges, and do not stir the water storage in the incubator. Sixth, the water temperature during the incubation period should be controlled at about 10 ℃. The results of expert experiments show that the proportion of female frogs in this water temperature can be increased by 20%.