Planorbis

Planorbis is a genus of freshwater snails belonging to the family Planorbidae. These snails are characterized by their flattened, discoidal shells, which are coiled in a single plane. This unique shell shape, resembling a coiled disc, is a defining feature of the genus and gives them their common name, "ramshorn snails."

Planorbis species are found in a wide range of freshwater habitats, including ponds, lakes, slow-moving streams, and even ditches. They are detritivores, feeding primarily on algae, decaying plant matter, and other organic debris found at the bottom of their aquatic environments. Their flattened shells allow them to navigate these substrates efficiently and to avoid being dislodged by water currents.

Reproduction in Planorbis typically involves hermaphroditic individuals, meaning each snail possesses both male and female reproductive organs. Mating occurs when two snails exchange sperm. Eggs are usually laid in gelatinous masses, often attached to submerged vegetation. The size and appearance of Planorbis snails can vary depending on the specific species and environmental conditions. Some species are small, while others can reach a more noticeable size. Due to their commonality and distinctive shells, they are often encountered by freshwater biologists and aquarium enthusiasts.