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The gastropod shell is part of the body of many gastropods, including snails, a kind of mollusc. The shell is an exoskeleton , which protects from predators, mechanical damage, and dehydration, but also serves for muscle attachment and calcium storage.
Gastropods typically have a well-defined head with two or four sensory tentacles with eyes, and a ventral foot. The foremost division of the foot is called the propodium. Its function is to push away sediment as the snail crawls. The larval shell of a gastropod is called a protoconch. [citation needed]
This shell has seven and a half whorls A fossil shell of the marine gastropod Turritella communis. This shell has nine whorls. A whorl is a single, complete 360° revolution or turn in the spiral or whorled growth of a mollusc shell. A spiral configuration of the shell is found in numerous gastropods, but it is also found in shelled cephalopods ...
Shell of marine snail Lunella torquata with the calcareous operculum in place Gastropod shell of the freshwater snail Viviparus contectus with corneous operculum in place. An operculum (Latin for 'cover, covering'; pl. opercula or operculums) is a corneous or calcareous anatomical structure like a trapdoor that exists in many (but not all) groups of sea snails and freshwater snails, and also ...
A spire is part of the shell of a snail, a gastropod mollusc, a gastropod shell, and also the whorls of the shell in ammonites, which are fossil shelled cephalopods. In textbook illustrations of gastropod shells, the tradition (with a few exceptions) is to show most shells with the spire uppermost on the page.
This gastropod is a simultaneous hermaphrodite. [5] It is the only species in the family Peltospiridae that is so far known to be a simultaneous hermaphrodite. [5] It has a high fecundity. [5] It lays eggs that are probably of lecithotrophic type. [22] Eggs of the scaly-foot gastropod are negatively buoyant under atmospheric pressure. [15]
Variety of Mollusc shells (gastropods: land snail shells and seashells). Closed and open shells of a marine bivalve, Petricola pholadiformis. A bivalve shell is composed of two hinged valves which are joined by a ligament. Four views of a shell of the land snail Arianta arbustorum The giant clam (Tridacna gigas) is the largest extant species of ...
Notched – Nicked or indented, as the anterior canal of some gastropods. [1] Nucleus – The first part or beginning, as the apex in a gastropod shell. [1] Nucleated – Having a nucleus. [1] Obconic – In the form of a reversed cone. [1] Oblique – Slanting, as the aperture of some shells when not parallel to the longitudinal axis. [1]