GENERAL HISTOLOGY

Detailed explanation-1: -Gastropods are a group of molluscs that include snails, conchs, abalones, whelks, sea slugs, and garden slugs. It is the only group that contains terrestrial molluscs. Therefore, the majority of gastropods are terrestrial. Some gastropods live in marine water, while some other types live in freshwater.

Detailed explanation-2: -Slugs and snails are in a subgroup called the Gastropoda, the members of which have a head, a ventral muscular foot, and a shell (internal in slugs and external on snails). Approximately 725 species of land snails and about 40 species of slugs are now known from North America.

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 The majority of gastropods have a single, usually spirally, coiled shell into which the body can be withdrawn.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: -Gastropods are a highly diverse Class of molluscs that include limpets, whelks, periwinkles, abalones, venomous cone shells, and the shell-less nudibranchs, sea slugs and sea hares.

Detailed explanation-5: -The phylum Mollusca is the second-largest animal phylum, with over 100, 000 species. The molluscs include many familiar animals, including clams, snails, slugs, and squid, as well as some less familiar animals, like tusk shells and chitons (Fig. 3.51 A).