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snails and slugs

Gastropoda

What do they look like?

The Class Gastropoda includes snails and slugs. Most gastropods have a single, usually spirally coiled shell, but the shell is lost or reduced in some groups. Many snails have an operculum, a plate that closes the gastropod's opening. Shelled gastropods have mantles, while those without shells have reduced to absent mantles.

Gastropods have a muscular foot used for creeping in most species. In some, the foot is modified for swimming or burrowing. Most gastropods have a well-developed head that includes eyes at the end of one to two pairs of tentacles.

Where do they live?

Gastropods are found worldwide. Gastropods are by far the largest group of molluscs. Their 40,000 species comprise over 80% of living molluscs.

What kind of habitat do they need?

Gastropods are found in freshwater systems, oceans, and on land wherever there is sufficient moisture.

  • Aquatic Biomes
  • lakes and ponds
  • rivers and streams
  • coastal

How do they grow?

Gastropods lay eggs. The eggs of some species contain a large yolk. Development of the eggs may be within the body, or the eggs may be expelled to develop externally. Eggs develop into larvae. Those species that will develop a shell start it while larvae. As the animal develops, it adds another curl of shell, ending in an opening from which the head and foot of the animal emerge.

What do they eat?

Gastropods feed on very small things. Most of them scrape or brush particles from surfaces of rocks, seaweeds, animals that don't move, and other objects. For feeding, gastropods use a radula, a hard plate that has teeth.

Gastropod feeding habits are extremely varied, although most species make use of a radula in some aspect of their feeding behavior. Some graze, some browse, some feed on plankton, some are scavengers or detritivores, some are active carnivores.

  • Primary Diet
  • carnivore
    • eats terrestrial vertebrates
    • eats non-insect arthropods
  • herbivore

Glossary

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends.

bog

a wetland area rich in accumulated plant material and with acidic soils surrounding a body of open water. Bogs have a flora dominated by sedges, heaths, and sphagnum.

carnivore

an animal that mainly eats meat

chaparral

mid-altitude coastal areas with mild, rainy winters and long, dry summers. Dominant plant types are dense, evergreen shrubs.

coastal

the nearshore aquatic habitats near a coast, or shoreline.

ectothermic

animals which must use heat acquired from the environment and behavioral adaptations to regulate body temperature

forest

forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.

freshwater

mainly lives in water that is not salty.

herbivore

An animal that eats mainly plants or parts of plants.

marsh

marshes are wetland areas often dominated by grasses and reeds.

mountains

This terrestrial biome includes summits of high mountains, either without vegetation or covered by low, tundra-like vegetation.

rainforest

rainforests, both temperate and tropical, are dominated by trees often forming a closed canopy with little light reaching the ground. Climbing plants are also abundant. There is plenty of moisture and rain, but may be somewhat seasonal.

saltwater or marine

mainly lives in oceans, seas, or other bodies of salt water.

scrub forest

scrub forests develop in areas that experience dry seasons.

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

swamp

a wetland area that may be permanently or intermittently covered in water, often dominated by woody vegetation.

temperate

that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).

terrestrial

Living on the ground.

tropical

the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.

 
University of Michigan Museum of ZoologyNational Science Foundation

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. "Gastropoda" (On-line), Animal Diversity Web. Accessed April 24, 2014 at http://www.biokids.umich.edu/accounts/Gastropoda/

BioKIDS is sponsored in part by the Interagency Education Research Initiative. It is a partnership of the University of Michigan School of Education, University of Michigan Museum of Zoology, and the Detroit Public Schools. This material is based upon work supported by the National Science Foundation under Grant DRL-0628151.
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