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Mollusk. Presented to you by Sequoya Hawkins and Samantha Swanik. Basic Information. Phylum Name: Mollusca Largest Marine Phylum Were one of the most successful of all animal groups Live in: Marine environments Freshwater environments Terrestrial environments Inhabiting trees
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Mollusk Presented to you by Sequoya Hawkins and Samantha Swanik
Basic Information Phylum Name: Mollusca Largest Marine Phylum Were one of the most successful of all animal groups Live in: Marine environments Freshwater environments Terrestrial environments Inhabiting trees Gardens Streams Estuaries Tidal Pools Beaches The Continental Shelf Deep Ocean
Diversity of Mollusks Over 150,000 species Gastropods Phylum name: Gastropoda More commonly known as slugs and snails Most diverse class 60,000 to 80,000 species
Diversity of Mollusks (cont’d) Bivalves Phylum: Bivalvia Have two part shells Has 30,000 species Exclusively aquatic Other names: Bivalva Pelecypoda Lamellibranchia
Diversity of Mollusks (cont’d) Cephalopods Phylum: Cephalopoda The dominant large predators Appeared over 500 million years ago Image-forming eyes Chitinous beaks Includes: Octopods Squids Nautiluses
Characteristics All have muscular mass of tissue called a foot • Mollusk foot functions in locomotion Multifunctional structure called a mantle Mollusk foot functions in locomotion An outgrowth of body surface that drapes over animal Rasping organ called a radula Have a coelom Open circulatory system
Body Support, Skeleton, and Movement • Mantle produces a shell • In most species • 3 Grouping of Mollusk: • Hatchet-footed • Live inside 2 shells • Referred to as bivalves • Belly-footed • 1 spiral shell • Carry shells on back • Called univalves • Head-footed • Definite head surrounded by tentacles
Reproduction • Sexual • Male and female structures are present in same individual • Except in polychaetes • Some snails are hermaphroditic • Sea slugs and oysters can change sex repeatedly • Internal fertilization • External in polychaetes • Reproduces with a large organ called a gonad
Digestion • Complete digestive tract (tube) • Has openings at both ends • Mouth and anus • Has specialized regions for digestion • The stomach and intestine • Steps in Mollusk digestion • Food brought through siphon system • Goes to mouth • Goes to digestive gland • Goes to intestine • Waste leaves via the anus
Examples of Mollusks • Snails • Nudibranchs • Slugs • Oysters • Clams • Octopuses • Squids • http://video.nationalgeographic.com/video/player/kids/animals-pets-kids/invertebrates-kids/nudibranch-kids.html
Bibliography • http://www.historyoftheuniverse.com/mollusc.html • http://geology.er.usgs.gov/paleo/mollusks.shtml • http://tolweb.org/Cephalopoda • http://www.earlham.edu/~burksje/mollusk%20pic.gif • http://www.mcwdn.org/Animals/Mollusks.html • http://www.jochemnet.de/fiu/BSC1011/BSC1011_13/tsld005.htm