gastropod, member of the class Gastropoda, the largest and most successful class of mollusks (phylum Mollusca Mollusca (məlŭs`kə)
..... Click the link for more information. ), containing over 35,000 living species and 15,000 fossil forms. The shell of gastropods is of one piece (called univalve) and usually coiled or spiraled as in snails snail, name commonly used for a gastropod mollusk with a shell. Included in the thousands of species are terrestrial, freshwater, and marine forms. Some eat both plant and animal matter; others eat only one type of food.
..... Click the link for more information. , periwinkles periwinkle, any of a group of marine gastropod mollusks having conical, spiral shells. Periwinkles feed on algae and seaweed. They are found at the water's edge; out of water, they resist drying by closing themselves into the shell with a horny plate.
..... Click the link for more information. , conches conch (kŏngk, kŏnch, kôngk)
..... Click the link for more information. , whelks whelk, large marine gastropod snail found in temperate waters. The whelk is sometimes eaten, but when food is plentiful, fishermen frequently use it for bait.
..... Click the link for more information. , limpets limpet, marine gastropod mollusk with a simple, flattened, conical shell, found in cooler waters of the Atlantic and the Pacific oceans. Certain species creep over rocks, feeding on algae during high tides, but when the tide recedes they return instinctively to the
..... Click the link for more information. , and abalones abalone (ăbəlō`nē), popular name in the United States for a univalve gastropod mollusk of the genus Haliotis,
..... Click the link for more information. ; however, in some forms, as in slugs slug, name for a terrestrial gastropod mollusk in which the characteristic molluscan shell is reduced to a thin plate embedded in the tissues. Like the terrestrial snails of the same order, slugs have a distinct head with a mouth, tentacles bearing eyes, and a lung
..... Click the link for more information. and sea slugs sea slug, name for a marine gastropod mollusk that lacks a shell as an adult and is usually brightly colored. Sea slugs, or nudibranchs, are distributed throughout the world, with the greatest numbers and the largest kinds found in tropical waters.
..... Click the link for more information. , it is reduced or completely absent. There is usually a definite head, bearing one or two sensory tentacles and a mouth that is often equipped with a rasplike tongue called a radula. The lower surface of the animal is modified into a large, flattened foot, used by bottom-dwelling forms for creeping about. The foot and other soft parts of the body can usually be completely withdrawn into the shell and the opening covered by a permanent plate called the operculum. Ancient gastropods were probably bilaterally symmetrical, but living species undergo a process known as torsion in which most of the body behind the head rotates 180° so that the anal and urinary openings are relocated behind the head, and the digestive tract and nervous system become U-shaped. Most gastropod species are marine but many groups, notably the pulmonate (lung-bearing) snails, have successfully invaded freshwater and moist terrestrial habitats.

gastropod

Any member of the class Gastropoda, the largest group of mollusks, including about 65,000 species. Gastropods, which include the snails, conchs, whelks, limpets, periwinkles, abalones, slugs, and sea slugs (see nudibranch), are found worldwide, in marine, freshwater, and terrestrial environments. Gastropods typically have a large foot with a flat sole for crawling, a single coiled shell that covers the soft body, and a head that bears a pair of eyes and tentacles. However, they are so diverse that some forms lack shells, while animals in one genus have shells with two halves, like bivalves. Most feed by using a radula, a ribbon of small horny teeth that tear food into pieces. They may be herbivores, carnivores, predators, parasites, or filter feeders of plankton and detritus.

gastropod (redirected from gastropodan)

gastropod

gastropod
(redirected from gastropodan)