GENERAL HISTOLOGY

Detailed explanation-1: -Traditionally, the three main gastropod groups are the prosobranchs (subclass Prosobranchia), the opisthobranchs (subclass Opisthobranchia), and the pulmonates (subclass Pulmonata); however, many authorities classify the pulmonates as a subgroup within subclass Opisthobranchia.

Detailed explanation-2: -Arthropods are a group of animals that includes insects, crabs, and spiders. Arthropods and gastropods share a common ancestor. This means that gastropods are more closely related to arthropods than they are to any other group of animals.

Detailed explanation-3: -The Class Gastropoda (in Phylum Mollusca) includes the groups pertaining to snails and slugs. The majority of gastropods have a single, usually spirally, coiled shell into which the body can be withdrawn. The shell of these creatures is often what is recovered in a fossil dig.

Detailed explanation-4: -Snails, slugs, and nudibranchs, or a slug-like saltwater animal, are all examples of gastropods.