1 / 122

Phylum Molluska

Phylum Molluska. Mollusks. Non-segmented Bodies Next to Insects, Most Successful Animal. Mollusks are widespread. One of the most successful of all animal phyla. Abundant in marine, freshwater, and terrestrial habitats. All Mollusks Share the Following Characteristics. 1. Body Cavity

ouida
Download Presentation

Phylum Molluska

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Phylum Molluska

  2. Mollusks • Non-segmented Bodies • Next to Insects, Most Successful Animal

  3. Mollusks are widespread • One of the most successful of all animal phyla. • Abundant in marine, freshwater, and terrestrial habitats.

  4. All Mollusks Share the Following Characteristics. • 1. Body Cavity • 2. Symmetry • 3. Organ System • 4. Three-Part Body Plan

  5. Three-Part Body Plan • Foot • Mantle • Visceral Mass

  6. Characteristics of a Mollusk • Objective: Explain the Evolutionary Relationship Between Mollusks and Annelids. • Both were the first to develop a true coelom. • Trochophore Larva.

  7. Picture of Trochophore Larva

  8. Organ Systems of Mollusks • Objective: Describe the Respiratory, Circulatory, and Excretory Systems of Mollusks.

  9. Respiration • Breathe with ciliated gills located in mantle cavity. • Extracts 50% of dissolved oxygen from water. • Some lack gills but mantle cavity functions as simple lung.

  10. Circulation • 3-chambered heart • Open Circulatory System • Only octopi and squids have closed circulatory system.

  11. Excretion: Early developers of an efficient excretory system. • Use coelom as a refuse dump • Nephridia filters wastes • Found in all coelomates except arthropods and chordrates. • Wastes out, molecules in.

  12. Organs of a Snail

  13. Classifying mollusks • Two Shelled: Bivalve • One Shelled: Gastropoda • No Shell: Cephalopods

  14. Section Objective • Describe four classes of Mollusks.

  15. Four classes of Mollusks • There are actually seven different classes of mollusks. But the four major are: • Polyplacophora • Bivalves • Gastropods • Cephalopods

  16. Bivalve

  17. Gastropod

  18. Cephalopod

  19. Polyplacophora • This class is one of the smaller classes and still has most of the characteristics of their ancestors. A chiton, of the class Polyplacophora

  20. Bivalves

  21. clam oyster mussel scallop

  22. Bivalves • Bivalves are characterized by two valves (shells), and siphons.

  23. Anatomy of Bivalve

  24. Movement • Bivalves use their foot to dig into the sand. • They may also close their valves rapidly, creating jet propulsion.

  25. Feeding • A bivalve filter feeds by sucking in sea water with one siphon and expelling it out the other.

  26. Respiration • Cilia that cover the gills draws water through one siphon, over the gills, and out the other siphon. • Bivalves also breath with the same gills that they feed with.

  27. Exception • One bivalve, the teredo, doesn’t filter-feed, it digests cellulose in wood using symbiotic protists in its intestine.

  28. Reproduction • Bivalves reproduce sexually. • The reproduce by shedding sperm and eggs into the water. • Bivalves can be either male or female, or the may be hermaphroditic.

  29. Gastropods

  30. Gastropods • They have a pair of tentacles, with eyes on its head • most have a single shell

  31. Gastropoda • The class Gastropoda include snails and slugs.

  32. Movement • A gastropod’s foot is adapted for locomotion. • Terrestrial species secrete mucus to create a path to glide across.

  33. Recognizable Features Eye • Most gastropods have two tentacles where the eyes are located on their head.

  34. Recognizable Features (cont.) • Except for slugs and nudibranchs (sea slugs), most gastropods have a single shell.

  35. Torsion • The visceral mass of gastropods rotate 180 degrees during development.

  36. Respiration • Gastropods respire using gills (aquatic species), directly through the skin or using the mantle cavity as a primitive lung (terrestrial species).

  37. Feeding • Gastropods have many different feeding habits: • Scraping algae off rocks (Radula) • Eating leaves • Eating other animals

  38. Snails Mating

  39. Cephalopods • Head-foot

  40. Head-foot • Cephalopods include squids, octopuses, cuttlefishes, and nautiluses. • Most of a cephalopod’s body is a large head attached to tentacles (the foot).

  41. Squid

  42. Octopus

  43. Octopus

  44. Octopus

More Related