The Economic Value of Toads and Artificial Breeding Techniques

Section 1: The Economic Value of Toads

The toad, commonly known as the warty toad, is not only a guardian of the fields that preys on pests, but also provides people with effective medicine for treating diseases, making it a medicinal animal of considerable economic value. The toad venom and toad skin collected from toads both have high medicinal value. Toad venom is made by processing and drying the white milky secretion from the glands behind the ears on the head (a pair of oval raised parts at the upper corners of the eyes) and the skin glands on the back; it is a traditional precious medicinal material in China. It has functions such as strengthening the heart and promoting urination, stimulating respiration, reducing swelling and opening the orifices, detoxifying and treating diseases, and providing anesthesia and pain relief. The world-renowned "Liushen Wan", "Meihua Dianshe Wan", "Ji Desheng Snake Medicine", and "Chanlisu" all contain toad venom as an ingredient, and there are as many as dozens of Chinese patent medicines made with toad venom as a raw material in China. Toad venom is also highly favored in China. Japanese doctors consider toad venom to be the most effective topical medicine for treating skin diseases, while Korea uses it for treating tumors with marked results. In domestic and international pharmaceutical markets, the demand for toad venom is increasing day by day. According to reports, in domestic and international pharmaceutical markets, the demand for toad venom is increasing day by day. According to reports, domestic procurement volume is only half of the demand. Drying toads after removing the internal organs produces dried toad, which has functions of reducing swelling and detoxifying, relieving pain, and promoting urination, and can treat chronic bronchitis, edema with difficult urination, and other conditions. In addition, in recent years it has been discovered that toads also have a certain anti-cancer effect. Toad skin is the skin naturally shed by toads; it has effects of clearing heat and detoxifying, reducing swelling and relieving pain, calming, promoting urination, strengthening yang, and resisting cold viruses. Artificially breeding toads is an emerging aquaculture industry that requires little money, has low costs, yields high returns, and involves simple technology that is easy to master.

Section 2: Biological Characteristics

Represented by the Chinese giant toad, also known as "Dian Ge Pao", belonging to Amphibia, Bufonidae. The toad has a large and stout body. Males generally have a body length of about 95 mm, females generally 105 mm, and large individuals can reach more than 120 mm; the head width is greater than the head length, the snout is round and high, there are no teeth in the mouth, and the interorbital space is greater than the internasal space; the forelimbs are relatively long and stout, and the hindlimbs are thick and short; the skin on the back is rough, with considerable color variation, mostly gray-green, black-brown, or reddish-green; there is a dark patch on the rear of the ventral surface and the groin area; males have black nuptial spines on the inner three fingers of the forelimbs and no vocal sac. On both sides of the toad's head there is a pair of elongated raised parotoid glands arranged in a "V" shape. These glands can secrete a white liquid, namely "toad venom".
The Chinese giant toad is distributed across various regions in northern and southern China, in hilly areas and flatland areas below 1,000 m in elevation. Except during the reproductive season, it mostly hides during the day under stones, in grass, or in earthen holes, and at dusk often moves about and forages along roadsides, field edges, grasslands, riverbanks, pond edges, ditch banks, and near homes, especially coming out in greater numbers after rain. Toads feed on small animals, such as snails, slugs, mosquitoes, as well as ants, locusts, katydids, and crickets. In southern and southwestern China, there is a species of black-spectacled toad that can consume large numbers of termites. The toad is clumsy, moves with a waddle, often crawls, and is not good at swimming or jumping. Because its hindlimbs are relatively short, it can only jump short distances, generally not exceeding 20 cm. In October, most toads enter the water and hide among underwater weeds, thin mud, or in earthen holes to overwinter. Toads are cold-blooded animals, and the length of their hibernation period varies with temperature differences across regions. Fertilization is external, and they are oviparous. After emerging from dormancy, toads enter water areas and begin amplexus and egg laying. The egg-laying season varies by region. In North China and the Inner Mongolia region, eggs are often laid in April-May, while in the Chengdu Plain they are laid in January-February. Amplexus generally lasts 9-12 hours, and in some cases up to 24 hours. The eggs are arranged in tubular gelatinous egg strings, about 10 m long, with about 5,000 eggs; the eggs are small, about 1.5 mm in diameter, with the animal pole black and the vegetal pole dark brown. Tadpoles are black, with weak and thin tail fins. From fertilized egg to metamorphosis into a young toad takes about 60 days. Young toads live a terrestrial life. Newly grown young toads have a body length of about 10-13 mm.
Toads have low requirements for habitat environment and are easy to breed and reproduce artificially.

Section 3: Feeding and Reproduction

I. Site Selection
The breeding site should be chosen in a place with ponds and pools, relatively abundant insect sources, and relatively warm temperatures. Generally, in front of and behind houses, abandoned ditches, abandoned ponds, or water pits can be used, and rice fields with convenient irrigation and drainage, sufficient water sources, and good water retention but relatively lean soil can also be selected as breeding sites. The breeding site should have a 1.5 m high wall built with bricks; plastic film or gauze netting can also be used as a wall, and it can also be woven from iron wire or small bamboo, to prevent toads from escaping. The inlet of the rice field should use plastic gauze netting as a water gate to block tadpoles from escaping.
II. Introducing Breeding Stock
When the breeding scale is very small, breeding toads mainly rely on capture. Adult toads mostly leave their hibernation burrows one after another at the end of March or in early April, slowly crawling out of water areas. Toads prefer warm, dark, and humid environments. Usually during the day they perch in grass by ditches, in earthen holes, or in dark and humid places such as bricks, tiles, and stone crevices behind houses, and are generally not easy to find. On rainy days or after rain, they are often very easy to catch on open ground by rivers or beside field paths. During spring plowing, toads also appear in relatively large numbers in rapeseed fields, green manure fields, and on the paths of seedling fields, and at this time they can be caught in large numbers. On warm, windless nights, this is the best time to catch toads. Every evening about 2 hours after dark until dawn the next day, toads come out to prey on insects, and they can be caught at any time. At this time, the place with the most toads is the open ground in front of and behind houses, and they are especially active around midnight each night. Sometimes in just a few hours, dozens of jin to several hundred jin of toads can be caught.