Mollusks
This presentation is the property of its rightful owner.
Sponsored Links
1 / 17

Mollusks : gastropods, bivlaves and cephalopods PowerPoint PPT Presentation


  • 228 Views
  • Uploaded on
  • Presentation posted in: General

Mollusks : gastropods, bivlaves and cephalopods. Mollusks: Soft-bodied animals that usually have an internal or external shell. Common mollusks are snails, slugs, clams, squid and octopi. Mollusks have a free-swimming larvae called a trochophore. Mollusk Body Plan:

Download Presentation

Mollusks : gastropods, bivlaves and cephalopods

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.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


Mollusks gastropods bivlaves and cephalopods

Mollusks:

gastropods, bivlaves and cephalopods


Mollusks gastropods bivlaves and cephalopods

  • Mollusks:

  • Soft-bodied animals that usually have an internal or external shell.

  • Common mollusks are snails, slugs, clams, squid and octopi.


Mollusks gastropods bivlaves and cephalopods

Mollusks have a free-swimming larvae called a trochophore.


Mollusks gastropods bivlaves and cephalopods

  • Mollusk Body Plan:

  • Four basic parts shared by most mollusks:

  • Foot: Muscular structure used for different purposes: crawling, digging and catching prey.

  • 2.Mantle: Thin layer of tissue around the body.

  • 3.Shell: Made by glands in the mantle. The shell is missing in some mollusks (slugs.)

  • 4.Visceral Mass: All the organs.


Mollusks gastropods bivlaves and cephalopods

Feeding:

Mollusks as a group eat all types of food.

Snails use a radula to scrape algae or drill into the shells of other mollusks.

Octopi and Squid use their jaws and sometimes poison to kll their prey.

Shellfish, like clams, are filter feeders. They use a siphon to bring in water and filter out the food.


Mollusks gastropods bivlaves and cephalopods

Respiration:

Water mollusks use gills in their mantle cavity to breathe. Land mollusks use diffusion to get oxygen .

Circulation:

A heart pumps blood through an open or a closed circulatory system. Slow mollusks use an open system, while fast ones use a closed system.

Response:

The nervous systems range from simple in shellfish to complex in the well-developed brains of intelligent Octopi.

Reproduction:

Some mollusks release eggs and sperm into the water, others mate and have internal fertilization.


Mollusks gastropods bivlaves and cephalopods

Gastropods:

-Have one shell or no shell at all, and crawl on a muscular foot on their ventral surface.

-Snails, slugs, limpets

-Shelled gastropods can hide inside their shells.

-Mollusks without shells either hide, squirt ink or contain poisons.


Mollusks gastropods bivlaves and cephalopods

  • Bivalves:

  • Have two shells held together with muscles

  • Clams, oysters, mussels, scallops

  • Most stay in one place, in the bottom or on rocks.

  • Most bivalves are filter-feeders, using their siphons to move water through their bodies.


Mollusks gastropods bivlaves and cephalopods

Cephalopods:

-Soft-bodied mollusks, where the foot is divided into tentacles.

-Include octopi, squid, cuttlefish and nautiluses.

-Eight or more tentacles with sucking disks for holding prey.

-Most cephalopods only have a small internal shell (cuttlefish) or none at all. The nautiluses have an external shell.

-Complex eyes and brains make cephalopods intelligent hunters.


  • Login