21. Gastropods Phylum mollusca (PrecambrianRecent) Class Gastropoda (Cambrian-Recent) Subclass Prosobranchia (Cambrian-Recent) http://paleo.cortland.edu/tutorial/Ceph&Gast/gastropods.htm

CEPHALOPODA, GASTROPODA GASTROPODS Phylum Mollusca (Precambrian-Recent) Class Gastropoda (Cambrian-Recent) Subclass Prosobranchia (Cambrian-Recent) Order Archaeogastropoda (Cambrian-Recent) Order Mesogastropoda (Ordovician-Recent) Order Neogastropoda (Cretaceous-Recent) Subclass Opisthobranchia (Carboniferous-Recent) Subclass Pulmonata (Carboniferous-Recent) Class GASTROPODA Gastropods, including such common forms such as snails, slugs, and whelks, occupy both marine and non-marine environments. Although many gastropods are herbivorous grazers, several groups are active carnivores able to drill through the skeleton of the luckless victim. Most of the gastropods are classified on the characteristics the gill structures and other soft-bodied features. Few distinguishing characters of the univalved shell are used in classification as many are the result of convergent evolution. Although the differences in the shell form may be difficult to recognize, different morphologic groups can generally can be differentiated on characteristics of ornamentation, shell shape, and aperture. The shell of many gastropods can either be external or, less commonly, internal.

22. Cephalopoda Classification and images of cephalopods from the Tree of Life project. http://tolweb.org/tree?group=Cephalopoda&contgroup=Mollusca

23. Mollusca Definition Of Mollusca In The Free Online Encyclopedia. mollusca (məlŭs`kə), taxonomic name for the one of the largest phyla of invertebrate animals (Arthropoda is the largest) comprising more than 50,000 living mollusk species and http://encyclopedia2.thefreedictionary.com/Mollusca

24. An Advanced Introduction To The Molluscsa (Molluscs) Printer Friendly version of article; but beware, this prints out all 59 pages( Internet Express) or36 pages (Netscape) (0.25 MB for the entire article. http://manandmollusc.net/advanced_introduction/mollusca_101_intro.html

Home Page Site Map ... Printer Friendly version of article . If you just want one section printed out, go to the specific class section that you want(see individual class sections listed at the bottom of this page). The Phylum Mollusca (an Introduction, for High-school level students, and all others interested!!) By Avril Bourquin Science Editing by Ross Mayhew May, 2000 Note: Glossary and separate page links are in blue and underlined. You may have to use your back button to navigate back to article when in the glossary or in external web sites or pages.. All of the Taxonomy in the Advanced Article is being updated for in regards to structure and picture content. Thank you for your patience Early Beginnings: The time is now about 600 million years ago and the first molluscs have made their appearance on our world. About 100 million years later, during the Ordovician period, at least six of the seven classes of molluscs represented today were present. Many of these first molluscs were but simple, worm-like animals, having segments similar to what we find in annelid worms and arthropods. These first molluscs crawled about the primeval seas, probing for and eating microscopic bits of food. The great landmass of Pangaea slowly deposits dissolved salts and other chemicals into the ocean. The first primitive molluscs in these oceans now digest these chemicals and begin to use the nutrients to build themselves protective shelters (shells) against their hostile environment. As Pangaea breaks apart around 200 million years ago, the world's great continents slowly migrate, due to plate tectonics, and we begin to recognize the world continents as they are today.

25. Introduction To The Scaphopoda Information about biology of the tusk shells, with illustrations and links. http://www.ucmp.berkeley.edu/mollusca/scaphs/scaphopoda.html

Introduction to the Scaphopoda the tusk shells The Scaphopoda are a distinctive group of molluscs commonly known as the "tusk shells" because their shells are conical and slightly curved to the dorsal side, making the shells look like tiny tusks (see the photos below). The scientific name Scaphopoda means "shovel foot", a term that refers to the "head" of the animal, which lacks eyes and is used for burrowing in marine mud and sediments. The most distinctive feature of scaphopods is that the tubular shell is open at both ends, not just one end as in most molluscs. Scaphopods live their adult lives buried in sand or mud, with their head-end pointed downwards. Only the narrow posterior end of the shell sticks up into the seawater for water exchange and waste expulsion. Gills have been lost in the scaphopods, so the mantle tissue not only produces the shell, but also serves the function of gills in obtaining oxygen from seawater. The mantle is fused into a tube that surrounds the body of the animal, but it is open at both ends. Water is circulated around the mantle cavity by the action of numerous cilia . When the dissolved oxygen runs low, the water is ejected through the top end of the shell by contraction of the foot.

26. Mollusca - LoveToKnow 1911 mollusca, one of the great phyla, or subkingdoms, of the animal pedigree or kingdom. The shell-bearing forms belonging to this group which were known to Linnaeus were http://www.1911encyclopedia.org/Mollusca

Mollusca From LoveToKnow 1911 MOLLUSCA, one of the great " phyla," or sub-kingdoms, of the animal pedigree or kingdom. The shell -bearing forms belonging to this group which were known to Linnaeus were placed by him (in 1748) in the third order of his class Vermes under the name " Testacea," whilst the Echinoderms, Hydroids and Annelids, with the naked Mollusca, formed his second order termed " Zoophyta." Ten years later he replaced the name " Zoophyta " by " Mollusca," which was thus in the first instance applied, not to the Mollusca at present so termed, but to a group consisting chiefly of other organisms. Gradually, however, the term Mollusca became used to include those Mollusca formerly placed among the " Testacea," as well as the naked Mollusca. Aristotle to indicate a group consisting of the cuttle-fishes only. As now classified, the Mollusca consist of the following subdivisions: - Grade A. - Isopleura. Class I. - Amphineura (see Chiton Grade B. - Prorhipidoglossomorpha. Class II. - Gastropoda Class III. - Scaphopoda Class IV. -

27. Wolfgang Fischer's Homepage Wolfgang Fischer Homepage. Publikationsliste updated. Images from the Ambrakian Gulf (Epirus, Greece) Die Molluskenfauna auf vier unterschiedlich bewirtschafteten Fl chen im http://ipp.boku.ac.at/private/wf/

MOLLUSCA Codringtonia codringtonii (Gray 1834) Aegopis sp. Albinaria sp. Wolfgang Fischer - Homepage Publikationsliste updated Images from the Ambrakian Gulf (Epirus, Greece) Fossil and recent Melanopsidae (recent and fossil species) updated (Check list of Austrian Mollusca with pictures) Fossil Miocene Mollusca European snails Euthria aracanensis ANGAS 1873 identification request Octopus from the Queensland coast, Yule Point (north of Cairns) Some landsnails of Bali ... links Hits since 02/01/99 No more guest book. Please send your comments to me directly: mailto: Wolfgang.Fischer@boku.ac.at new pictures added and updated 16.03.2004 wf

28. Mollusca Photos On Fotopedia - The Photo Encyclopedia The mollusca, common name molluscs or mollusks, is a large phylum of invertebrate animals. There are around 85,000 recognized extant species of molluscs. This is the largest marine http://www.fotopedia.com/en/Mollusca

29. Mollusca - Guide To The Marine Zooplankton Of South Eastern Australia Fact sheet with photographs and information on the distinguishing characteristics, distribution and ecology of mollusc larvae, Veliger larvae and Pteropoda larvae. http://www.tafi.org.au/zooplankton/imagekey/mollusca/

30. Palaeos Metazoa: Mollusca: Phylum Mollusca An overview of the molluscs, with coverage of recent and extinct groups. http://www.palaeos.com/Invertebrates/Molluscs/Mollusca.htm

Palæos Mollusca METAZOA Mollusca Page Back Unit Back Metazoa Cladogram ... Page Next Unit Next Unit Home Unit Cladogram Unit References Glossary ... Time Phylum Mollusca PROTOSTOMIA ARTHROPODA Trilobita PANCRUSTACEA ... LOPHOTROCHOZOA MOLLUSCA BASAL MOLLUSCA Rostroconchia BIVALVIA CYRTOSOMA ... PULMONATA `ANNELIDA Unit Contents Mollusca Shell Morphology Basal Mollusca Bivalvia ... References Page Contents Mollusca Physiology Diversity Habitat ... Links The Mollusks are a large and diverse group of soft-bodied unsegmented animals. Nearly 130,000 recent species are known, and some 35,000 fossil species. They include many familiar animals, like snails, clams, squid, octopi, etc, as well as others not so well known. They range in size from microscopic forms to the giant squid (Architeuthis), and have a long and venerable history appearing during earliest Cambrian time, if not before. Physiology All mollusks possess some or all of the following characteristics: a muscular fleshy foot which with gastropods (snails) is used to crawl along with but in cephalopods is modified into tentacles a visceral mass containing the digestive, excretory, and reproductive organs

31. Mollusks Introduction to the major molluscan classes. http://www.cyhaus.com/marine/mollusk.htm

Mollusks Phylum Mollusca There is one thing that all mollusks have in common: a foot. The foot is used for different purposes in each class, as you will see. Here are four classes of mollusks: 1) Class: Cephalopoda 2) Class: Bivalvia 3) Class: Gastropoda 4) Class: Polyplacophora BACK TO THE INVERTEBRATES PAGE!

32. Molluscum Contagiosum Because they can spread by skinto-skin contact, mollusca are usually found in areas of skin that touch each other such as the folds in the arm or groin. http://www.aad.org/public/publications/pamphlets/viral_mollscum.html

Home Contact Us Site Map Sign in ... Clinical Resources for Researchers Find a Dermatologist Zip Code: Radius: 5 Miles 10 Miles 25 Miles 50 Miles 100 Miles 150 Miles Molluscum Contagiosum Home Public Center A common skin disease, molluscum contagiosum is caused by a poxvirus that infects only the skin. This virus enters the skin through small breaks in the skin barrier. After an incubation period, growths appear. These growths can develop anywhere on the skin. Like warts, which are caused by a different virus, molluscum contagiosum is considered benign. Molluscum contagiosum does not affect any internal organs and rarely causes symptoms. As the name implies, molluscum contagiosum is contagious. WHAT MOLLUSCUM CONTAGIOSUM LOOKS LIKE Mollusca are usually small flesh-colored or pink dome-shaped growths that often become red or inflamed. They may appear shiny and have a small central indentation or white core. Because they can spread by skin-to-skin contact, mollusca are usually found in areas of skin that touch each other such as the folds in the arm or groin. They also are found in clusters on the chest, abdomen, and buttocks and can appear on the face and eyelids. Sometimes, the growths appear in a row. Molluscum contagiosum with HIV infection In people who have a disease that weakens the immune system, the mollusca may be very large in size and number, especially on the face.

33. Mollusca phylum porifera cnidaria ctenophora platyhelminthes nemertinea sipunculida annelida arthropoda bryozoa brachiopoda mollusca echinodermata chordata http://library.thinkquest.org/26153/marine/mollusca.htm

MOLLUSCA PHYLUM: PORIFERA CNIDARIA CTENOPHORA PLATYHELMINTHES ... BRACHIOPODA MOLLUSCA ECHINODERMATA CHORDATA BACK TO : KINGDOM ANIMALIA (Latin.mollis = soft) This phylum is one of the largest marine groups with over 80 000 species. All comprise of a soft, unsegmented body, consisting of an anterior head, a dorsal visceral mass and a ventral foot.The body is more or less surrounded by a fleshy mantle (an outgrowth of the body wall) and nearly all species in the group secrete a lime shell that covers and protects the body. All, except the class Bivalvia , have a ribbon-like rasping tongue (radula - unique to this phylum) with small chitinous teeth that processes the food. Most mollusks are free living, but slow moving creatures, showing a close association with the substrate. Some attach to rocks or shells, others burrow, others float, octopuses and squids swim freely. Characteristics: 1. Body usually short and partially or wholy enclosed by a fleshy outgrowth of the body wall called the mantle, which may be variously modified. Between the mantle and the visceral mass is a mantle cavity containing components of several systems (secondarily lost in a few groups). 2. A shell (if present) is secreted by the mantle and consists of one, two or eight parts. the head and the ventral muscular foot are closely allied (the foot being variously modified for burrowing, crawling, swimming, or food capture).

34. Mollusca Name another group of organisms that have done so much for humans as the mollusks. They've been food, decoration, tools, even medicine money; and nowadays, aquarium specimens. http://www.wetwebmedia.com/mollusca.htm

document.write(jscode); Home Information Pages: Marine Aquarium Articles/ FAQs Freshwater Aquarium Articles/ FAQs ... Articles/ FAQs Popular Pages: Features: Daily FAQs FW Daily FAQs SW Pix of the Day FW Pix of the Day ... Cover Images Related FAQs: Mollusks Sea Slugs Related Articles: Gastropods/Snails Sea Slugs Abalone Cephalopods (Squid, Cuttlefish, Octopus) ... Chitons The Conscientious Marine Aquarist Mollusks: An Overview Bob Fenner A Cyphoma gibbosum feeding on a fan The myriad mix of animals we call mollusks; clams really big and small, Chitons, octopus, snails, abalone, oysters, nudibranchs, sea hares, nautilus, squid, tusk shells and many more, are finally starting to get their due with marine aquarists. With improvements in water quality, foods, and collecting, transportation and handling technology what were once sure losers are being kept for months to years. I am amazed at the parallel worlds of aquarium and "shell-collecting" interests. In late 1994, I was privileged to present my views to the Southern California Marine Aquarium Conference on issues of the ethics, and government control of marine livestock trade practices. One weekend later, I gave almost the identical talk to the annual meeting of the Conchologists of America, Inc. (a national organization of shell collectors). Our concerns are the same; no one wants to see the natural resource/environment negatively impacted by their participation; neither group sees the real use of government intervention. You may have a total disinterest in mollusks up to this point, but should be aware of them as a group. If for no other reasoning than they may "show up" in your system as "extras" on live rock, macro-algae, other invertebrates or foods. Many are predatory on other invertebrates; anemones, sea urchins, other mollusks, and even fishes. A few can be fatally dangerous to the aquarist.

35. Mollusca Kingdom Animalia PHYLUM mollusca triploblastic eucoelomate. INTRODUCTION Evolutionarily, the molluscs apparently derive from the platyhelminthes. http://www.esu.edu/~milewski/intro_biol_two/lab__11_mollusca/Mollusca.html

Kingdom Animalia PHYLUM MOLLUSCA - triploblastic eucoelomate INTRODUCTION Evolutionarily, the molluscs apparently derive from the platyhelminthes. They are classified as triploblastic eucoelomate animals, as are all phyla remaining to be examined. Most molluscs are bilaterally symmetrical and have well-defined circulatory, respiratory, excretory, and digestive systems. The molluscs are a large group, second only to arthropods in number of species. The name "mollusc" is derived from the Latin molluscus ("soft"), indicating that the molluscs are soft bodied animals. The group includes the snails, bivalves, chitons, squid, octopuses, and others. In some forms, the soft bodies are protected by a calcareous shell. The organisms in the phylum Mollusca are characterized by having three main body areas: a head-foot (sensory and locomotion structures), a visceral mass (excretory, digestive, and circulatory structures), and a mantle (which secretes the shell). The gills, which function in respiration, are located between the visceral mass and the mantle. Representatives of the following classes will be studied in this exercise: Class Polyplacophora - the chitons Class Gastropoda - snails, slugs

36. ADW: Mollusca: Classification What do these icons mean? The icons tell you what features are available for that taxon. Information Pictures Specimens Sounds Selecting an icon will take you directly to that feature. http://animaldiversity.ummz.umich.edu/site/accounts/information/Mollusca.html

Overview News Technology Conditions of Use ... Home Kingdom Animalia Phylum Mollusca Phylum Mollusca (mollusks) Pictures Specimens Classification What do these icons mean? The icons tell you what features are available for that taxon. Information Pictures Specimens Sounds Selecting an icon will take you directly to that feature. Confused by a class within a class or an order within an order ? Please see our brief essay Scientific names for Aves taxonomy (family and below) are from The Howard and Moore Complete Checklist of the Birds of the World Parent taxa Kingdom Animalia (animals) Eumetazoa (metazoans) Bilateria (bilaterally symmetrical animals) Protostomia (protostomes) Lophotrochozoa Trochozoa Phylum Mollusca (mollusks) Class Cephalopoda (octopuses and squids) Class Gastropoda (gastropods, slugs, and snails)

37. Mollusca — FactMonster.com Encyclopedia mollusca. mollusca (m u lŭs'k u) , taxonomic name for the one of the largest phyla of invertebrate animals (Arthropoda is the largest) comprising more than 50,000 living http://www.factmonster.com/ce6/sci/A0833641.html

Home U.S. People Word Wise ... Homework Center Fact Monster Favorites American Indian Heritage Month Math Flashcards Geography Guide Seven New Wonders of the World ... The Fifty States Reference Desk Atlas Almanacs Dictionary Encyclopedia ... Encyclopedia Mollusca Mollusca (m u u key , taxonomic name for the one of the largest phyla of invertebrate animals (Arthropoda is the largest) comprising more than 50,000 living mollusk species and about 35,000 fossil species dating back to the Cambrian period. Mollusks are soft-bodied, and most have a prominent shell. The members of this highly successful and diverse phylum are mostly aquatic and include the familiar scallop clam oyster mussel ... chiton , and a variety of others. Mollusks occupy habitats ranging from the deep ocean to shallow waters to moist terrestrial niches. Certain mollusks, such as clams, squids, and scallops, constitute important food staples, and molluskan shells are highly valued by collectors. In times past these shells were used as money and today are used ornamentally for such items as buttons and jewelry. There are six classes of mollusks. Sections in this article: Introduction Anatomical Features Class Amphineura Class Monoplacophora Class Gastropoda ... Class Cephalopoda The Columbia Electronic Encyclopedia

38. Mollusca | Define Mollusca At Dictionary.com –noun the phylum comprising the mollusks. Use mollusca in a Sentence See images of mollusca Search mollusca on the Web Origin 1790–1800; NL, neut. pl. of L molluscus http://dictionary.reference.com/browse/Mollusca

39. Mollusca The phylum mollusca is a very diverse group that includes clams, snails, and octopus. The samples in your kit are from the groups generally called the bivalves (clams) and http://msnucleus.org/membership/html/jh/biological/mollusca/lesson1/mollusca1a.h

Back MOLLUSCA Lesson 1 - Page 1 Next The phylum Mollusca is a very diverse group that includes clams, snails, and octopus. The samples in your kit are from the groups generally called the bivalves (clams) and gastropods (snails). Gastropods are coiled while bivalves have two shells that are bilaterally symmetrical. Bivalves have very interesting shells that can help illustrate to your students different living habitats. An important point to emphasize with students is that in shells the living organisms are gone, but on the shell many times information is imprinted. Not in words but in subtle clues that the organism leaves behind. Many of the features that will be described may not be on shells that you purchase from a "shell shop." This is because they polish many of the shells before they sell them, removing some of the "clues." Let's try to see what key characteristics you can discover and compare on your shells. Have your students compare shell shape, shell weight, structure of the inside of the shell and coloration. Notice the many shapes that your Mollusca samples have in your kit. Most of these shapes are adapted to their living habitat and if you identify which structures give you clues, you can reconstruct where these animals live. The color of many of these organisms depend on how recently they died, for instance the sand dollars are a brilliant purple when alive, but become white after they die and bleached by the Sun or chemicals. The gastropods are colorful in life and maintain this color, but they in time would lose their color.

40. Redirecting Now... Listing of major taxa in the region in all molluscan classes with line drawings of some species. http://turin.net/catalogue_shell/

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