Ramshorn snail. Photo by Amanda Goodman.

Kingdom: Animalia-
Members of the kingdom Animalia are multicellular, heterotrophic organisms (rely on ingestion to acquire their nutrients) that lack cell walls.

Phylum: Mollusca-
The phylum Mollusca is comprised of coelomates that are soft-bodied and are divided into three main body parts: the head (except for the bivalves), a muscular foot, and a visceral mass. Most members also possess a toothed-tongue, called a radula. You can read more about the radula on the nutrition page.

Class: Gastropoda-
Known as the "belly foots," this class includes such animals as snails, slugs, and limpets. Most of the members of this class have a single shell that is coiled. Another characteristic of the Gastropods is "torsion" or the twisting of the visceral mass.

Subclass: Pulmonata-
This subclass includes freshwater snails and slugs. Members of the subclass Pulmonata acquire oxygen by the use of a "lung" or pulmonary cavity, unlike other members of the class Gastropoda.

Order: Basommatophora
Members of the order Basommatophora have a single pair of tentacles, with eyes located at the base. Organisms in this group are more primitive than some of the land snails in the subclass Pulmonata.

Family: Planorbidae
The family Planorbidae is comprised of the freshwater Pulmonates. The Planorbidae are the largest family as far as the number of genera and species are concerned. The Planorbidae include such creatures as the "wheel snails," the "orb snails," and of course, the Ramshorn snail!

Genus: Helisoma
The genus Helisoma is composed of many types of Ramshorn snails, including the common Ramshorn snail found prevalently in aquatic environments across North America and Canada.

Species: H. trivolvis
The common Ramshorn snail!


Click the thumbnail below to see a phylogenetic tree for the domain, kingdom, phylum and class of H. trivolvis
Domain through class.


Click the thumbnail below to see a phylogenetic tree for the class, subclass, order and family of H. trivolvis
Phylogenetic tree of the Ramshorn snail. Class, Subclass, order, family.