A snail is a shelled gastropod. The name is most often applied to land snails, terrestrial pulmonate gastropod molluscs. However, the common name snail is also used for most of the members of the molluscan class Gastropoda that have a coiled shell that is large enough for the animal to retract completely into. When the word "snail" is used in this most general sense, it includes not just land snails but also numerous species of sea snails and freshwater snails. Gastropods that naturally lack a shell, or have only an internal shell, are mostly called slugs, and land snails that have only a very small shell are often called semi-slugs.
Gastropods, commonly known as slugs and snails, belong to a large taxonomic class of invertebrates within the phylum Mollusca called Gastropoda.
The chambered nautilus, also called the pearly nautilus, is the best-known species of nautilus. The shell, when cut away, reveals a lining of lustrous nacre and displays a nearly perfect equiangular spiral, although it is not a golden spiral. The shell exhibits countershading, being light on the bottom and dark on top. This is to help avoid predators, because when seen from above, it blends in with the darkness of the sea, and when seen from below, it blends in with the light coming from above.
The grove snail, brown-lipped snail or lemon snail is a species of air-breathing land snail, a terrestrial pulmonate gastropod mollusc.
The common periwinkle or winkle is a species of small edible whelk or sea snail, a marine gastropod mollusc that has gills and an operculum, and is classified within the family Littorinidae, the periwinkles.
Marsupella profunda, the western rustwort, is a liverwort native to Europe and known only from Portugal and Great Britain (Cornwall) and has been sighted in the Canary Islands. It is a small reddish liverwort and can be confused with Marsupella sprucei which has a more widespread distribution.
Helix pomatia, common names are the Roman snail, Burgundy snail, or escargot, is a species of large, air-breathing stylommatophoran land snail native to Europe. It is characterized by a globular brown shell. It is an edible species. Helix pomatia commonly occurs synanthropically throughout its range.
The Brazilian three-banded armadillo is an armadillo species endemic to eastern Brazil, where it is known as tatu-bola. It is one of only two species of armadillo that can roll into a ball. It has suffered a 30% decline in population in the last 10 years.
The red-crowned roofed turtle or Bengal roof turtle is a species of freshwater turtle endemic to South Asia. It was the type species of its former genus Kachuga. Females can grow to a shell length of 56 cm (22 in) and weigh 25 kilograms (55 lb), but males are considerably smaller. The turtles like to bask in the sun on land. In the breeding season, the heads and necks of male turtles exhibit bright red, yellow and blue coloration. The females excavate nests in which they lay clutches of up to thirty eggs.
The periostracum is a thin, organic coating that is the outermost layer of the shell of many shelled animals, including molluscs and brachiopods. Among molluscs, it is primarily seen in snails and clams, i.e. in gastropods and bivalves, but it is also found in cephalopods such as Allonautilus scrobiculatus. The periostracum is an integral part of the shell, and it forms as the shell forms, along with the other shell layers. The periostracum is used to protect the organism from corrosion.
Fraxinus profunda, the pumpkin ash, is a species of ash (Fraxinus) native to eastern North America, where it has a scattered distribution on the Atlantic coastal plain and interior lowland river valleys from the Lake Erie basin in Ontario and New York west to Illinois, southwest to Missouri and southeast to northern Florida. It grows in bottomland habitats, such as swamps, floodplains and riverbanks. It is threatened by the emerald ash borer, an invasive insect which has caused widespread destruction of ash trees in eastern North America.
The western oriole, or western black-headed oriole, is a species of bird in the family Oriolidae that is native to Africa. The adult upperparts are yellow-olive, and the underparts are yellow in colour. It is rated as a species of least concern on the International Union for Conservation of Nature Red List of Endangered Species.
The painted rocksnail is a species of freshwater snail with a gill and an operculum, an aquatic gastropod mollusc in the family Pleuroceridae.
Bradybaena similaris, the Asian trampsnail, is a species of small, invasive land snail. It is a pulmonate gastropod terrestrial mollusc in the family Bradybaenidae. It earned the common name based on its origins, and its habit of roosting on freight containers. This habit means that this may be one of the most broadly-distributed species of terrestrial snail in the world. Bradybaena similaris is the type species of the genus Bradybaena.
Polygyridae is a family of air-breathing land snails, terrestrial pulmonate gastropod mollusks in the superfamily Helicoidea.
Allogona is a genus of air-breathing land snails, terrestrial pulmonate gastropod molluscs in the family Polygyridae.
Calcinus elegans, also known as the blue line hermit crab, is a small, tropical hermit crab.
Cellana talcosa, the talc limpet or turtle limpet is a species of true limpet, a marine gastropod mollusc in the family Nacellidae, which is one of the true limpet families. This species is endemic to the Hawaiian islands, where its common name is koele or opihi ko'ele. It is the largest limpet found in the Hawaiian islands and can reach 4 in (100 mm) in diameter.
Lissospira is a genus of sea snails, marine gastropod mollusks in the family Skeneidae.
Chelodina (Chelydera) expansa, commonly known as the broad-shelled river turtle or the broad-shelled snake-necked turtle, is a pleurodiran freshwater turtle and is the largest of the long-necked turtles. The broad-shelled river turtle is one of the oldest-maturing and longest-living species of freshwater turtles in existence and occurs in wide sympatry with Emydura macquarii and Chelodina longicollis. C. expansa is listed as ‘vulnerable’ in South Australia and ‘threatened’ in Victoria.
