Viviparous viviparous is sometimes known as the river snail ,freshwater winkle, mystery snail or trapdoor snail. It is sometimes confused with the similar Chinese trapdoor snail (Bellamya chinensis). Viviparous viviparous is a large native snail species and can reach 3.5 cm but 2.5 is more common. This species has a very tough shell and can be kept with large carp, goldfish and other large fish that would eat most other snails species and its operculum (trapdoor) prevents it being sucked out of its shell by smaller fish such as loaches. They are great algae grazers and will graze algae from rocks, glass and plants (they wont eat live plants). As well as scavenging detritus, dead fish and plants and left over fishfood, they also filter-feed algae, bacteria and small particles from the water like mussels and are excellent at clearing green or murky water. Being a native species it can survive UK winters, but can also be kept in coldwater and tropical aquariums. Snails make up an essential part of a pond or aquarium ecosystem and would make an excellent addition to a wildlife pond.
Large trapdoor snail (Viviparus viviparus) green water cleaners
Viviparus viviparus is hardy and can survive in a wide range of conditions and is very easy to keep, although like most aquatic snails it can be sensitive to acidic water (low ph). They can easily survive from scavenging and don't need any additional food, especially if being kept in an outdoor pond. However, if you want to put extra food in for them, they can be fed algae wafers, bloodworm pellets, shrimp pellets or fishfood. Viviparus is a slow breeder and has 1 live young at a time so is a good choice if you dont want a large snail population. Unlike many other aquatic snails but same as tropical apple snails (Pomacea sp) which it is closely related to, Viviparous viviparous is not a hermaphrodite and each snail is either male or female. Its operculum (trapdoor) and tough shell makes it immune to predation from most fish, even large koi and goldfish and is a highly saught after species.