Scientific Name
Kingdom: Animalia (Animals)
Phylum: Mollusca (Mollusks)
Class: Gastropoda (Mollusks with one or two pairs of fleshy tentacles)
Subclass: Pulmonata (Breathing through a lung-like sac)
Order: Basommatophora
Family: Planorbidae
Description
The orb snail has one pair of tentacles with the eyes at the base of its tentacles.
Habitat
Most snails are found clinging to substrates or dredging vegetation and surface layers of sediment. Some may also burrow in sand. It may be difficult to see snails at the surface of the water, because they will often drop to the bottom of the water, if even slightly disturbed.
Diet
Orb snails primarily eat decaying plants or algae growing on rocks.
Water Pollution Sensitivity
Orb snails are semi-tolerant to water pollution. They have some natural defenses, because they have an additional projection from their foot called a pseudobranch that acts as a gill. This gives the Orb snail an additional way obtain oxygen. Additionally, the snails can move to the surface of the water to obtain oxygen for their lung. This gives them the ability to live in waters that do not have much dissolved oxygen.
Resources Consulted
http://watermonitoring.uwex.edu/wav/monitoring/biotic3.html
http://www.esg.montana.edu/aim/mollusca/gastropd.html