Physa fontinalis, common name the Common Bladder Snail, is a species of air-breathing freshwater snail, an aquatic gastropod mollusk in the family Physidae. The shells of species in the genus Physa are left-handed or sinistral. This species has a wide distribution in the western Palaearctic region but confusion with similar species makes the eastern limits of its distribution uncertain. Physa fontinalis is an opportunist inhabiting streams, rivers, ponds, lakes, springs, canals and irrigation ditches. It occurs in both nutrient-poor and richly vegetated habitats. It may be found in (moderately) polluted waterbodies.
The shell is 7 to 12 mm high and 4 to 7 mm wide. The spiral has four to five whorls (the last of which forms more than three-quarters of the shell height) and the apex is rounded. The shell is very thin-walled, translucent, shiny and is a pale horn colour. The aperture is wide and oval, and the mouth edge is very thin and brittle. The body color is brown to black, some are well spotted. The edges of the mantle extend as finger-like lobes over the exterior of the shell. The tentacles are long, slender and cylindrical, with the eyes at the base. The foot is long and thin. Bladder snails are hermaphrodites.
These snails actually do a very good job at eating algae and cleaning up after messy fish and plant litter. They are a pretty quick moving snail, and they are very good at getting to food sources and eliminating them. Physa fontinalis are not fussy what they eat. Their primary diet is algae but will take anything your offer will be greatly received, algae wafers, blanched vegetables such as courgette and spinach, brussel sprouts, cucumber, fish flakes, shrimp pellets, red peppers and so on.
The Common Bladder Snails care is pretty easy and straightforward. The snails are a hardy species and they are adaptable to a range of water conditions. They easily tolerate water temperatures from 5°C to 30°C. Water hardness and pH are not really critical. Care must be taken to avoid any sort of exposure to copper and other medications because this can be fatal to snails. Finally, be mindful that the snails may need Calcium supplements to maintain a healthy shell.