Class GastropodaClass Gastropoda

The UnivalvesThe Univalves

ZoologyZoology

Class GastropodaClass Gastropoda

Class Class GastropodaGastropoda is the is the largest and most diverse largest and most diverse group of mollusk. group of mollusk.

Over Over 70,000 70,000 living living gastropod species are gastropod species are still currently found on still currently found on earth today. Overearth today. Over

15, 00015, 000 fossil species have fossil species have been discovered.been discovered.

Class GastropodaClass Gastropoda

Class Gastropoda Class Gastropoda includes includes snailssnails, , limpetslimpets, , slugsslugs_, _, whelks, conchs, whelks, conchs, periwinkles, periwinkles, sea sea slugsslugs, sea hares, and , sea hares, and sea butterflies.sea butterflies.

Gastropod HomesGastropod Homes

Gastropods live in Gastropods live in aquatic aquatic and and terrestrial terrestrial environments. environments. Gastropods that live Gastropods that live on land have on land have adapted an area in adapted an area in their mantle into a their mantle into a lung lung so that they can so that they can breathe out of water.breathe out of water.

UnivalvesUnivalves Gastropods are Gastropods are

univalvesunivalves, which means , which means that they have one shell.that they have one shell.

The shell is made of The shell is made of oneone piece and may be coiled piece and may be coiled or uncoiled. or uncoiled.

The The apexapex, or center of , or center of the shell is the oldest the shell is the oldest part of the shell. part of the shell.

The spirals on the shell The spirals on the shell are called are called whorlswhorls. . Whorls may curl to the Whorls may curl to the right right or or left left depending on depending on the the genetic genetic makeup of makeup of the gastropod. the gastropod.

Gastropod Bodies and Gastropod Bodies and TorsionTorsion

Gastropods are primarily Gastropods are primarily bilaterally bilaterally symmetrical. symmetrical.

However, the middle part However, the middle part of their body is of their body is asymmetrical because of asymmetrical because of torsiontorsion, which is a , which is a process that twists the process that twists the mantle cavity mantle cavity 180 180 degrees relative to the degrees relative to the head and foot. head and foot.

Gastropods are the only Gastropods are the only molluskmollusk that undergo that undergo torsion.torsion.

Gastropod DefenseGastropod Defense

Gastropods defend Gastropods defend themselves by themselves by twotwo primary ways: primary ways: their shell their shell and and their mucustheir mucus..

Gastropods also have Gastropods also have symbiotic relationships symbiotic relationships with some Cnidarians. with some Cnidarians. In some cases, the In some cases, the gastropod can control gastropod can control the Cnidarian’s the Cnidarian’s stinging stinging tentaclestentacles to defend to defend against predators.against predators.

The Gastropod DietThe Gastropod Diet

Gastropods are primarily Gastropods are primarily grazersgrazers. They are . They are primaryprimary consumers in consumers in their ecosystem because their ecosystem because they feed on plants. they feed on plants. They use their They use their radularadula, , which is a combination of which is a combination of a tongue and teeth, to a tongue and teeth, to cutcut and and scrape scrape food. food.

Pesky Little PestsPesky Little Pests

Gastropods are a Gastropods are a garden pest garden pest because because they often eat they often eat landscaping plants landscaping plants and their population and their population can be hard to can be hard to control through control through conventional conventional pesticides.pesticides.

Salt and Snails….Salt and Snails….

Snails lose the Snails lose the water water in their bodies in their bodies through the diffusion through the diffusion of water, or of water, or osmosisosmosis, , when salt is poured when salt is poured on their body. Water on their body. Water leaves the leaves the body cellsbody cells of the snail to of the snail to balance the salty balance the salty environmentenvironment..