Clams Bivalve mollusks Appearance A clams shell consists two - - PowerPoint PPT Presentation

Clams

“Bivalve mollusks”

Appearance

• A clam’s shell consists two halves that are

usually equal which are connected by a hinge joint and a ligament that can be internal or external.

• Most clams have smooth outer shells.

Features

• Clams have two adductor muscles contract to

close the shells.

• No head or mouth (besides scallops)
• Have kidneys, a heart, a mouth, and an anus
• Have a natural glue that causes it to connect to
• ther shells or things at the bottom of the river/sea
• Clams are bilateral

Clam parts

Facts

• There are approximately 2000 different species
• f clams
• 20% of them are not edible
• Oysters make Pearls, not clams. They are not

the same, but very similar

Reproduction

• Clams may be male, female, or both
• Females produce up to 60 million eggs in a
• season. They release the eggs into open water

and then the male releases sperm. The eggs are fertilized in open water

Growth

• Once fertilized, the young clam goes through a

larvae stage where it is carried by waves and

• currents. Eventually it develops a shell and sinks

to the bottom where it feeds on plankton

• Once the shell is developed, clams dont grow as

much anymore

Evolution

• Clams and cephalopods first appeared in the

lower to middle Ordovician period

• Clam-like Brachiopods existed before Earth’s

largest mass extinction

• After the clarity when little existed, a different

kind of clam-like organism called a Bivalve, took

• ver

Clams today

• As you may know, clams are most useful in

providing food for us

• We also use the shells for multiple other reasons

Works Cited

• www.Wikipedia.com
• www.astrobio.net
• Yahoo answers