Ptilinum

Ptilinum is a genus of small, often minute, freshwater snails with an operculum, aquatic gastropod mollusks in the family Hydrobiidae. The name Ptilinum is derived from the Greek word "ptilinos," meaning "feathered," referring to the fine, hair-like structures on the shell. These snails are typically found in slow-moving or stagnant freshwater habitats, such as ponds, lakes, and marshes.

The genus Ptilinum includes several species, each with distinct morphological characteristics. The shell of Ptilinum species is usually small, ranging from 1 to 3 millimeters in length, and is typically conical or oval in shape. The shell is often smooth or slightly ribbed, and the color can vary from translucent to brown or gray. The operculum, or lid, is a distinctive feature of Ptilinum snails, providing protection for the soft parts of the animal.

Ptilinum snails are herbivorous, feeding on algae and other plant material. They play an important role in freshwater ecosystems by contributing to nutrient cycling and maintaining water quality. Despite their small size, Ptilinum snails are of interest to scientists and hobbyists alike, due to their unique morphology and ecological significance.