Impellaria

Impellaria is a genus of small, freshwater snails with an operculum, aquatic gastropod mollusks in the family Viviparidae. The genus was first described by the French zoologist Jean-Baptiste Lamarck in 1816. Impellaria species are commonly known as viviparous snails due to their ability to give birth to live young. They are found in various freshwater habitats, including ponds, lakes, and slow-moving rivers, primarily in Europe and North America.

The shell of Impellaria species is typically small, ranging from 2 to 5 millimeters in length, and is usually conical or fusiform in shape. The shell is often translucent, with a smooth or slightly ribbed surface. The operculum, or lid, is present and is used to close the shell opening when the snail is not active.

Impellaria snails are herbivorous, feeding on algae and other plant material. They are known for their ability to reproduce both sexually and asexually. Sexual reproduction involves the release of sperm and eggs into the water, where fertilization occurs. Asexual reproduction, on the other hand, involves the production of parthenogenetic offspring, which develop from unfertilized eggs.

Impellaria species play a role in freshwater ecosystems by controlling algal growth and contributing to the breakdown of organic matter. Despite their small size, they are an important component of the aquatic food web, serving as a food source for various predators, including fish and other invertebrates.