stagnalis

Stagnalis is a Latin species epithet used in the scientific names of several organisms. Derived from stagnālis, it means "of stagnant water" or "standing water" and is commonly applied to species associated with still or slow-moving aquatic habitats.

The best-known example is Lymnaea stagnalis, the great pond snail, a freshwater gastropod native to Europe and parts of Asia and North Africa. Lymnaea stagnalis has a long history in science as a model organism in neurobiology and physiology because of its relatively large, identifiable neurons and accessible nervous system.

The epithet stagnalis appears across multiple taxa beyond Lymnaea, including other mollusks and various invertebrates described in older taxonomic classifications. In modern nomenclature, many of these names have been revised or recombined under different genera, but stagnalis remains a recurring descriptor in the historical literature.

As with any species epithet, stagnalis alone does not define a single organism or trait; it indicates a habitat association or a descriptive attribute that was relevant to the taxonomist who named the species.