html5-img
1 / 25

Chapter 35

Chapter 35. Section 1 Molluska. Characteristics of Mollusks. Some are filter-feeders while others are fast-moving predators with complex nervous systems Coelomates - true body cavity. Characteristics of Mollusks. Aquatic mollusks have a larval stage of development called a trochophore

sulwyn
Download Presentation

Chapter 35

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. Chapter 35 Section 1 Molluska

  2. Characteristics of Mollusks • Some are filter-feeders while others are fast-moving predators with complex nervous systems • Coelomates- true body cavity

  3. Characteristics of Mollusks • Aquatic mollusks have a larval stage of development called a trochophore • Trochophores are motile and disperse throughout bodies of water

  4. Body Plan of Mollusks • 2 main regions- head-foot & visceral mass • Head-foot- consists of the head, mouth, sensory structures, and foot- large muscular organ usually used for locomotion

  5. Body Plan of Mollusks • Visceral mass- (located above the head-foot) contains the heart, organs of digestion, excretion, & reproduction • Visceral mass is covered by a layer of epidermis called the mantle

  6. Body Plan of Mollusks • Most mollusks- mantle secretes hard shells containing calcium carbonate • Why have a shell???

  7. Body Plan of Mollusks • Mantle cavity- space between the mantle and visceral mass • Gills are protected by mantle cavity

  8. Body Plan of Mollusks • Ganglia- more complex nervous system that controls locomotion, feeding, and sensory information (light, touch, etc)

  9. Body Plan of Mollusks • Radula- main feeding adaptation • Tongue-like strip of tissue covered with tough, abrasive teeth that point backwards • Terrestrial snails- cut through leaves • Aquatic snails- scrape algae

  10. Class Gastropoda • Gastropods • snails, conchs • slugs & nudibranchs

  11. Snail

  12. Conch

  13. Slug

  14. Nudibranch

  15. Class Bivalvia • Bivalves- two shells connected by a hinge • Closes its shell with adductor muscles, when the muscles relax, the valves open • Most bivalves are sessile

  16. Class Bivalvia • Clams • Bury in sand or mud • Feeding: Cilia beats on the gills and set up a current of water that enters through the incurrent siphon and leaves though the excurrent siphon

  17. Clam

  18. Class Cephalopoda • Cephalopod- “head foot” • Free-swimming & have tentacles • Nervous system is advanced- cephalopod brain is largest invertebrate brain • Ex: Octopi can perform tasks & distinguish between objects

  19. Class Cephalopoda • Release dark fluid to distract predators • Chromatophores- pigment cells that allow the organism to change colors quickly

  20. Squid • Move by pumping in water though their siphons • Largest invertebrate- Architeuthis- 60 feet long and up to 2,000 lbs!

  21. Octopus

  22. REVIEW!!! • What purpose does a radula have? • Describe the characteristics of mollusks. • Name the three major classes of mollusks & an example of each.

More Related