Molluscs
- Snails, clams, octopuses, and other familiar forms are members
-The body is covered by a mantle, a thin layer of tissue that that secretes the shell
-This unsegmented body is typically bilateral symmetrical
-There is a ventral, muscular foot, usually used in locomotion
-A feature unique to molluscs is the radula, a ribbon of small teeth that is used to feed, usually by rasping food from surfaces
-The radula is made primarily of chitin
- Gastropods
-Snails, limpets, abalones, and nudibranches
-They typically are a coiled mass of vital organs enclosed by a dorsal shell
-The shell rests on a ventral creeping foot and is usually coiled
-Most gastropods use their radula to scrape algae from rocks
-Most are vegetarian, but some are carnivorous
- Bivalves
-The body is laterally compressed(flattened sideways) and enclosed in a shell with 2 parts, or valves
-The umbo, the upper hump near the hinge of the shell, is the oldest part of the shell
-They have no head, and no radula
-The gills, expanded and folded, are used not only to obtain oxygen but also to filter and sort small food particles from the water
-The inner surface of the shell is lined by the mantle, so the whole body lies in the mantle cavity, a large space between 2 halves of the mantle
-Strong muscles, the adductor muscles, are used to close the valves
-Clams use their shovel-shaped foot to burrow in the sand or mud
-Siphons allow these buried clams to feed and obtain oxygen
- Cephalopods
-Nearly all are agile swimmers with a complex nervous system and a reduction or loss of the shell
-The body is protected by a thick and muscular mantle
-Water enters through the free edge of the mantle and leaves through the siphon, or funnel, which projects under the head
-Cephalopods swim by forcing water out of the mantle cavity through the siphon.
Sponges
-tissues and organs are mainly what there made up with
-sessile are living permanently attached to a surface
-ostia are tiny pores on sponges
-plankton are organic particles that sponges filter and eat
-they are classified as phylum porifera
* Glass sponges - live in deep water lace like skeleton of fused spicules
*Boring sponges - bore thin channels through calcium carbonate
-tissues and organs are mainly what there made up with
-sessile are living permanently attached to a surface
-ostia are tiny pores on sponges
-plankton are organic particles that sponges filter and eat
-they are classified as phylum porifera
* Glass sponges - live in deep water lace like skeleton of fused spicules
*Boring sponges - bore thin channels through calcium carbonate
Cnidarians
- Jelly fish, anemones, and coral
- Radial symmetry
- Aboral surface - Where the mouth is located, usually surrounded by tentacles.
- Tentacles - Finger like extensions used to catch prey
- Gut - food is digested in
- Polyp - sac-like attached stage that later turns into a Medusa
- Medusa- Upside down polyp adapted to swimming
- Created through layers of cells and cell walls
- many forms of life
- nematocyst is a projectile stinger!
- Comb jellies!
- Incredibly soft textures
- colloblasts - sticky cells