Oncomelania hupensis a kind of shellfish. Like snails and snails, it is also a gastropod with a right-handed shell. Because it is very small and looks like a small screw, it is also called nail snail, or snail for short. The shells of Oncomelania hupensis have great changes with different species and regions, some of which have longitudinal ribs and some are smooth. Oncomelania hupensis has a well-developed head and two slender antennae. There are eyes outside the base of the antenna. Its kiss is very similar to that of a snail, with a mouth at the front and a toothed tongue inside. Oncomelania hupensis an amphibious snail. Larvae mostly like to live in water, and adults generally like to live in grass in wet areas above the water line. Generally, the environmental conditions for snail breeding can be divided into three types: one is "water net type", which means that in some plain areas, rivers crisscross, and snails breed in rivers, irrigation ditches and other places along the waterline, and are rarely found in paddy fields and ponds. Oncomelania shells bred in this area are thicker and have thinner longitudinal ribs on the shell surface; One is "lake-swamp type", which refers to the lake-swamp area. Oncomelania snails mostly live in the branches of lakes, beaches, grass beaches, reed beaches along rivers and other places along the coast of lakes and swamps. Oncomelania snails breed in such areas with large and thick shells and thick longitudinal ribs on the shell surface; The other is "mountain type", which refers to mountainous areas. Oncomelania snails are mainly distributed in rivers and rice fields, and also found in hillside grasslands in some areas. Oncomelania snails in these areas have thin shells and smooth shells without longitudinal ribs. Oncomelania hupensis dioecious and oviparous. Mating can be carried out all year round, with the most copulators in spring and the second in autumn. You can lay eggs from November to July of the following year, but you can lay eggs most in March-May. Eggs are laid in moist soil, and larvae can hatch in less than one month at a suitable temperature (16-23℃). The hatched larvae mature in two months when the food is abundant and the temperature is suitable. Many species of snails living in fresh water are intermediate hosts of human or livestock parasites. Some parasites have to live in these snails at a stage before they can be transmitted to humans or livestock. Without this stage, parasites can't complete their life history, so they can't continue to live, and of course they can't be transmitted to humans or livestock. Therefore, these snails have become vectors of some diseases. Oncomelania hupensis the intermediate host of Schistosoma japonicum, and this parasite is the pathogen of schistosomiasis japonica, a very serious chronic disease that harms our people. Schistosomiasis japonica is prevalent in 13 provinces and cities in the south of China. It is parasitic in the small blood vessels of the portal vein system of human body, and its metabolites are toxic, which can destroy human tissues and make people lose their normal physiological functions. Therefore, the eradication of Oncomelania hupensis is one of the important measures to control schistosomiasis japonica.