Physa (snail)

Class: Gastropoda

Superfamily: Planorboidea

Family: Physidae

Genus: Physa

Identifying Characteristics:

- Left-handed or sinistral, air-breathing freshwater snail

- Possess a complex of muscles that is unique amongst gastropods.

• This complex was given the name “physid musculature”. The physid musculature has two main components, the physid muscle sensu stricto and the fan muscle. The physid musculature is responsible for a unique ability of physids to rapidly flick their shells from side to side — a reaction that frequently enables them to escape predation.

-The shells of Physa species have a long and large aperture, a pointed spire, and no operculum. The shells are thin and corneous, and rather transparent.

Special Adaptations:

- Freshwater snails

- Eat algae, diatoms, and detritus