Phylum Mollusca

___________________ symmetry Body Cavity - ___________________ Body has three distinct regions –_________________ - central section, which contains the body's organs –____________ - Means “cloak” in Greek. Wraps around the visceral mass, secretes shell. Mantle cavity -space between mantle & visceral mass. –________________ - Ventral, muscular and prominent. Functions: –Locomotion - Bivalvia use to dig into sand –Securing food - modified into a tentacle in Cephalopods

Digestive System _______________- rasping organ in Gastropods, Beak in Cephalopods All mollusks except Bivalvia have this structure. Used to scrape algae off rocks (Gastropoda) or as a weapon to puncture holes in prey (Cephalopoda) Has mouth, esophagus, stomach, intestine and anus. Digestive gland secretes ______________ into the gut.

Excretory System __________________ wastes dumped into coelom. Cilia in nephridium cause fluid (wastes and nutrients) to move through nephridia. Nutrients are _________________; wastes empty into the mantle, then removed.

Circulatory System __________________________ for all except Cephalopoda. ______________________ - Coelom - restricted to the region around the Dorsal Aorta.

Respiratory System ___________ located in their mantle cavity ____________ beat continuously causing a steady stream of _________ to pass over the gills. Gills also trap ___________

Nervous System Ring of ___________________ around esophagus Two sets of ventral ________________ Nerve fibers maybe quite large - ________ __________________, _______________ and ________________ receptors

Reproductive System Male and female ___________________ fertilization

Major Classes Class _____________________ Class _____________________ Class ______________________ Class ______________________

Class _______________ - Snails and slugs Examples: ________________ - Sea slugs _________________ secretes hard protective ____________. Some don't have shell. All _________________ mollusks are in this class, but most members are __________. Terrestrial mollusks don't have ___________.

Class Gastropoda - Snails and slugs Uses _________________ to scrape algae for food ______________ adapted for locomotion. It forms a slimy path then ungulates foot (wave like motion) ______________ are located on a pair of stalk like tentacles on the head

Class ________________ - Clams, oysters and scallops Examples - ___________________________, Name means: bi - “______", valva - “_________________________" Edge of _______________ secretes a two part hinged shell. Composed of __________________________. Shell shows _________________ lines. No distinct ____________ region, but have a central ________________ above foot Most are _______________, exception scallops and shipworms. Most are __________________

Class Bivalvia Nervous System- touch and ______________ _____________________ System _______________________ connect the two valves together. ________________________ used to dig into the sand and locomotion Nutrition - __________________________. Use a hollow tube called a ________________ to pull in water. Water is then drawn over the _________ then out the ___________________ siphon.

Class Bivalvia Reproduction ______________, Most species have separate sexes, few hermaphrodites. Shed ________ and _________ into water. Fertilization is ______________. _________________ develops into a free swimming ____________________ larva. Teredo (_____________) - feeds on ______________ that it ingests

Class _____________________ - chitons Shell is embedded in _______________ Mantle cavity has two lateral grooves on each side of body where gills are located. Use _______________ to scrap algae Reproduce __________________, Separate sexes

____________________ feet) Invertebrate

Cephalopods History appeared some time in the late ____________ several million years before the first primitive fish began swimming in the ocean Scientists believe that the ancestors of modern cephalopods (Subclass Coleoidea: octopus, squid, and cuttlefish) diverged from the primitive externally shelled Nautiloidea (Nautilus) very early - perhaps in the Ordovician, some 438 million years ago.

Cephalopod Hist. cont Cephalopods were once one of the dominant life forms in the world's oceans Today there are only _______ or so living species of cephalopods (compare that with 30,000 living species of bony fish). However, in terms of productivity, some scientists believe that cephalopods are still giving fish a run for their money

_____________________ __________ swimming predatory animals Extremely ____________________ Cephalopods foot is divided into tentacles –squid=____ tentacle –octopus=_____ tentacle –cuttle fish=_____or more tentacle

Cephalopods distinct structures Cephalopods have large, well developed ________ that form images Tentacles are covered with _____________ for seizing and holding prey Cephalopods have a _________ like structure in their digestive tract called a ______________ for breaking down food Cephalopods mouth has two strong ______________ for tearing its prey apart. Cephalopod is fitted with a ____________ like structure that fills with water and ejects it acting like a ____________________________

Cephalopods masters of deception Able to change _________________ Can expand and contract _____________ cells in its _________ _____________________(color cells) give the cephalopod the ability to change. Can eject _____ when alarmed causing the enemy to be temporarily blinded. The ink also inactivates predators chemical receptors used for detecting prey.

Cephalopods Diet Feed on crabs, shrimp, fish, and other cephalopods

Cephalopods Habitat ____________ to ___________ Polar to tropics In other words they are found __________________

Giant Squid Giant squid get up to _____ feet (20 m) in length and easily hold the record as the ________________________________ Despite the size of these beasts no one has ever seen one alive in its natural environment Main Diet of the __________________ Giant squid were once mistaken for sea monsters in sailing days