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ZOO 115 Invertebrate Zoology

ZOO 115 Invertebrate Zoology. Mollusca. Mollusca – Classes. Monoplacophora Aplacophora Polyplacophora Gastropoda Bivalvia Scaphopoda Cephalopoda. Gills. Mantle Cavity. Mantle. Foot. Mouth. www.manandmollusc.net/advanced_introduction/Images/Monoplacophora2.gif. Anus.

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ZOO 115 Invertebrate Zoology

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  1. ZOO 115 Invertebrate Zoology Mollusca

  2. Mollusca – Classes • Monoplacophora • Aplacophora • Polyplacophora • Gastropoda • Bivalvia • Scaphopoda • Cephalopoda

  3. Gills Mantle Cavity Mantle Foot Mouth www.manandmollusc.net/advanced_introduction/Images/Monoplacophora2.gif Anus animaldiversity.ummz.umich.edu/site/resources/Grzimek_inverts/Monoplacophora/Laevipilina_antarctica.jpg/medium.jpg Mollusca – Class Monoplacophora • Resemble the generalized mollusc • Small (3 mm), flattened molluscs that inhabit deep water • Present in the Cambrian period – thought to be extinct until 1952 • Single shell

  4. Mouth http://www.labsis.usc.es/workshop/images/common/2.jpg Gills Mantle Cavity Pedal groove or foot Mollusca – Class Aplacophora www.manandmollusc.net/advanced_introduction/aplac.html • ~ 300 species • Small benthic dwellers between 200-7000m • Shell-less • Secrete calcareous spicules on epidermis • Foot reduced or absent • No eyes, tentacles, statocysts, or nephridia

  5. Mollusca – Class Polyplacophora • ~800 sp • Ancient (since late Cambrian) • Lives in rocky-intertidal region • Has series of plates for a shell. • It is an herbivore (except for one species)

  6. http://www.ucd.ie/cobid/chitons/glossary_images/2002a0404131-c.jpghttp://www.ucd.ie/cobid/chitons/glossary_images/2002a0404131-c.jpg http://www.ucd.ie/cobid/chitons/glossary_images/2002a0404135-b.jpg Mollusca – Class Polyplacophora

  7. Mollusca – Class Gastropoda • Marine and terrestrial • 2nd largest class in animal kingdom • Hard shell (most)

  8. Mollusca – Class Gastropoda variety

  9. Mollusca - Class Gastropoda • Herbivores and predators. • Has a radula • Hard shell (most) • Well developed head and cephalic tentacles • Locomotion – peristalsis of foot. http://www.pirx.com/gallery/albums/mollusks/radula.jpg

  10. /www.ling.helsinki.fi/~simon/gallery/snails Mollusca – Class Gastropoda Anatomy

  11. /www.sfu.ca/~msr/Papers/BISC/images/nucelladesiccation Columellar muscle How can it do both? Tarsos muscle Mollusca – Class Gastropoda - foot • Columellar muscle • Retracts head and foot into shell • Extends head and foot • Twists foot • Tarsos muscle • Bottom of foot and edges • Locomotion • Prey capture • Molding of eggs • No fluid filled hemocoel

  12. http://etc.usf.edu/clipart/25100/25194/shell_25194_lg.gif http://www.palaeos.com/Invertebrates/Molluscs/Gastropoda/Images/Bellerophon.jpg http://content.answers.com/main/content/wp/en/a/a1/Snail-WA_edit02.jpg http://www.cartage.org.lb/en/themes/Sciences/Paleontology/Paleozoology/FossilMollusks/AboutAmmonites/enroulement.jpg http://www.cartage.org.lb/en/themes/Sciences/Paleontology/Paleozoology/FossilMollusks/AboutAmmonites/enroulement.jpg Uncoiled Mollusca – Class Gastropoda Shell Coiling Planospiral Whorl

  13. Anus position Gill position http://www.weichtiere.at/images/weichtiere/schnecken/torsion.gif http://palaeo.gly.bris.ac.uk/Palaeofiles/Fossilgroups/gastropo/Diagrams/tort.gif Torsion • 180◦ counterclockwise rotation of visceral mass WHY?

  14. Torsion - WHY? • Larval theory – allows foot to be brought up into shell

  15. Torsion - WHY? • Adult theory – • allows for better ventilation of mantle cavity and gills • Places osphridium anteriorly • May help increase efficiency of creeping with a coiled shell

  16. http://eebweb.arizona.edu/collections/Fishes/Invertebrate%20Slide%20Photos/Invertebrate%20Photos/Abalone%201.jpghttp://eebweb.arizona.edu/collections/Fishes/Invertebrate%20Slide%20Photos/Invertebrate%20Photos/Abalone%201.jpg http://www.mesa.edu.au/friends/seashores/images/limpet_under.gif Problem from torsion • Sanitation • Slits or holes to accommodate waste • Unidirectional flow of water

  17. Class Gastropoda - Diversity • Subclass – Prosobranchia • Order Archeogastropoda • Order Mesogastropoda • Order Neogastropoda • Subclass Ophistobranchia • Subclass Pulmonata Molecular evidence indicates that these classifications are no longer valid!

  18. Subclass Prosobranchia - • Usually with a spirally coiled shell (whorl) • Mantle cavity anterior • Osphridium (not shown) • Gills • Anus • Nephridiopore (not shown) http://www.nmfs.noaa.gov/pr/images/invertebrates/blackabalone_anatomy.jpg http://snugglynoodles.com/images/haeckel/Haeckel_Prosobranchia.jpg

  19. Order Archeogastropoda • Primative • Herbivores • Radula has numerous teeth in transverse rows • 1-2 bipectinate gills • Mantle cavity without siphon • Sexes separate

  20. http://www.anth.ucsb.edu/faculty/glassow/RAMP/abalone.jpg http://www.marlin.ac.uk/imgs/Species/Mollusca/o_diogra.jpg Order Archeogastropoda • Abalone • Keyhole limpets • Limpets* * Order Patellogastropoda http://www.marietta.edu/~biol/biomes/images/shores/shield_limpet_6150.jpg

  21. http://elrinconmarinosgasteropodos.iespana.es/Fotos%20coleccion/Cerithidae.jpghttp://elrinconmarinosgasteropodos.iespana.es/Fotos%20coleccion/Cerithidae.jpg http://seashellplace.com/catalog/images/BullmouthCameoHelmet.jpg Olividae Cerithidae Vermetidae http://elrinconmarinosgasteropodos.iespana.es/Fotos%20coleccion/Janthinidae.jpg http://www.timespub.tc/fileadmin/user_upload/featured/Summer2004/Shell%2028.jpg Carinaridae Turritellidae Cassidae Cypraeidae http://www.eumed.net/malakos/Images/Carinaria_mediterranea.jpg Hydrobia Calyptraeidae Naticidae Strombidae Tonnidae Capulidae http://www.dkimages.com/discover/previews/965/50007882.JPG http://www.seashell-collector.com/beginners/CALYPTRAEIDAE.jpg http://www.maier-kern.com/wordpress/wp-content/uploads/2006/02/DSC02058.JPG Janthinidae http://www.shellmuseum.org/Shells2/alatus2.jpg http://www.seashell-collector.com/beginners/CAPULIDAE.jpg http://www.seashell-collector.com/beginners/CYPRAEIDAE.jpg http://www.seashell-collector.com/beginners/OLIVIDAE.jpg Order Mesogastropoda http://www.seashell-collector.com/beginners/FICIDAE.jpg

  22. http://oceanica.cofc.edu/shellguide/pics/univalve.gif Order Mesogastropoda • Operculum present • Radula with seven teeth/row • Only left gill – unipectinate • One atrium • One nephridium

  23. Order Neogastropoda

  24. Order Neogastropoda • Entirely marine • Radula with 3 or fewer teeth per row • One gill • One atrium • One nephridim

  25. Order Neogastropoda

  26. Mollusca – Order Neogastropoda Cone snail

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