Key Points on the Rearing and Management Techniques for Juvenile Frogs
Frog farming is very common in China, but as we all know, frogs evolve from tadpoles, so when the tadpoles and juvenile frogs finally grow into adult frogs, the growing environment required at each stage is different.
Rearing and Management of Juvenile Frogs
1. Intensive domestication: with high-density concentrated captive rearing, a density of 100-150 frogs per sq m can be used, reared in a cement pond with smooth inner walls and a height of more than 1 m, with a water depth of about 20 cm, and a feeding platform placed on the water surface; no land area is provided inside the pond, forcing the juvenile frogs to come onto the platform to feed and rest together.
2. Bait domestication: first feed with live bait for 1-2 days, then on the 3rd day begin adding 20% artificial feed to the bait, and increase the proportion day by day thereafter, until after 10 days it is increased to 80%. "Live bait" mainly includes earthworms, fly maggots, small fish and shrimp, insects, snails and loaches; "dead bait" refers to dried silkworm pupae, animal
3. Viscera and compound feed, etc.: use motion to lead stillness, activate the "dead bait", and finally transition to complete feeding on artificial bait. At the same time, feeding is required to be timed, quantitative and at fixed locations. Feeding time: in spring and autumn around noon, in summer in the evening or morning; feed 1-2 times a day, and each feeding should take about 1 hour
4. After juvenile frogs finish eating: for juvenile frogs weighing less than 50 grams, the feeding amount should be 6-8% of body weight; for juvenile frogs weighing more than 100 grams, the feeding amount should be 8-10% of body weight. The bait is required to be fresh, clean and nutritious.
5. Screening, grading and separate rearing: when juvenile frogs have been domesticated for 20-30 days, the pond water should be drained, and the large-sized juvenile frogs should be transferred to adult frog ponds at a density of 60-80 per sq m; the small-sized juvenile frogs remain in the original pond for domestication. Using feed bait, indoor three-dimensional, multi-layer box and cage intensive farming is a new method of frog farming. Raising frogs in plastic boxes and wooden boxes for small-scale farming gives extremely high yields, with several hundred frogs able to be raised per sq m, and generally only 5 months are needed from hatching to adult frog.
Selection of Breeding Frogs
1. Breeding frog selection: select frogs that have spawned for the second time as breeding frogs; second-spawn breeding frogs have a relatively high fertilization rate, while although female frogs in the third and fourth years lay a large number of eggs, the fertilization rate is relatively poor, and first-year frogs also have a relatively low egg hatching rate, so they are not suitable as breeding frogs. For ease of management, it is best to select those with a strong body shape, normal development and active movement from the same batch of breeding frogs.
2. Stocking density: after selection, place breeding frogs into the spawning pond for spawning at a ratio of 1 male frog to 2-3 female frogs; generally a 20 sq m spawning pond can hold 1400-2000 breeding frogs.
3. Spawning pond management: place aquatic plants or water lilies in the breeding frog spawning pond, with the amount accounting for about one third of the water surface; loofah or grapes and the like must be planted above the pond to build frames for shade, and strong sounds and other noises should be avoided as much as possible around it. If a spawning pond is built in the middle of a rice field, set spawning baskets in the spawning pond; the spawning basket has an upper opening diameter of 30 cm, a lower opening diameter of 70 cm and a height of 40 cm, and each spawning basket holds 20-30 groups of breeding frogs. Observe frequently; if egg masses are found, scoop them out and put them into the hatching pond, then release the female frogs that have already spawned, so that the male frogs continue to amplex.
What Food Do Tadpoles Eat
Tadpoles are the larvae of amphibians such as frogs, toads, newts and giant salamanders. Most tadpoles scrape and eat algae with rows of keratinized teeth in their mouths, but if there happen to be some small animal carcasses such as earthworms and beetles in the water, they will also feed on them in groups. Some kinds of tadpoles have no keratinized teeth and feed by filtering plankton from the water. The tadpoles of the emerald tree frog are egg-eating, and the mother frog returns regularly to lay eggs to feed the tadpoles. When food is insufficient, the phenomenon of larger tadpoles eating smaller tadpoles can also occur.
Frogs love to eat small insects and are good at spotting moving small insects. Usually a frog lies in a small pit in the soil, with its hind legs folded and kneeling on the ground, supported by its front legs, mouth open and face upward, belly puffing in and out while waiting for something; when a mosquito flies over and flashes in front of the frog, the frog's body suddenly leaps upward, its tongue flips out, then it lands again on the ground, the mosquito is gone, and it sits back exactly as before, waiting for the next prey to arrive.
Hatching Management of Frogs
1. Spawning time: frogs spawn every year from March to July; spawning is later in the north, while in the southern provinces spawning begins in March, and April is the peak spawning period. However, the timing of amplexus, mating and spawning of breeding frogs has a great deal to do with air temperature, the water temperature of the rearing pond and the water depth. When the water temperature is above 15°C, male and female frogs begin to amplex, and 18-28°C is the most suitable spawning temperature.
2. Artificial induction of spawning: not every sexually mature breeding frog can spawn; factors such as unsuitable environment, poor development, poor physique and harsh climate can affect spawning. In order to make frogs spawn and hatch uniformly, artificial induction of spawning must be carried out. Usually the pituitary injection method is used: open the top of the head of a frog, remove the brain, and beneath the brain there is a white object about half a grain in size, which is the pituitary. Put the pituitary into a sedimentation tube, grind it with a glass rod, add physiological saline to dissolve it, and then use a sterilized syringe to inject it into the leg muscle of the female frog; two injections can make the female frog spawn.
3. Amplexus and spawning: when the spawning season approaches, male frogs call continuously to attract female frogs. Male frogs generally come into estrus about a week earlier; when the female frog is not in estrus she refuses amplexus, and when she is in estrus she often lingers in shallow water or on the bank, staying around the male frog, with her belly more swollen than usual, sexual impulse, and appetite suddenly reduced. Frogs have no copulatory organ and cannot carry out internal fertilization; instead, fertilization is completed by the male embracing the female. The male frog has an enlarged fleshy pad on the inner side of the first finger, called the nuptial pad. The nuptial pad is rich in glands and keratinized spines, and its secretions and keratinized spines reinforce the embracing effect. When the female frog is mature and in estrus, the male frog jumps onto the female frog's back, clasps his forelimbs below the female frog, squeezes the female frog's abdomen with his lower legs, and at the same time swings his two hind feet to rub the female frog's cloacal opening; the female frog discharges eggs out of the body, and the male frog immediately releases sperm onto the eggs.
As we all know, frogs are amphibians; they can live not only in water but also on land. When farming frogs, farmers must first understand the living habits of frogs, which is very helpful for frog farming.