• Class Bivalvia
• Formerly known as Pelecypoda
• There are more than 15 thousand species of:
– Mussels
– Oysters
– Scallops
– Clams
– Numerous other families of shells
Characteristics
• All shells have two pieces known as valves
• In most, valves are similar size.
• Shells vary greatly in size, color, and
ornamentation
• The foot of bivalves is adapted for
burrowing in all species, except for the
sedentary ones
• Some use the foot to hop from place to
place
•
Some have siphons
Most have single pair of large gills
Used for respiration
Used for trapping food particles
Fresh Water Mussels
• Freshwater mussels can be less than .1
inches
• Giant clam shell can exceed 4 feet in
length
•
•
582 pounds
Can live up to 40 years
• Filter Feeders & how they work
• Plankton, larvae, eggs and detritus
• Modern issues in filter feeding
– Susceptibility to harmful pollutants
– Algal blooming
– Effects on humans
• All bivalves make pearls
• Sand gets embedded in the mantle
• Secretion of aragonite and conchiolin
• Development of simple eyes in swimming
bivalves
– After the ability to swim
• Ability to burrow
– Foot
– sihpons
• No need to develop a head
• Evolution of their shell
• Scallop video
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Elevel, Martina. "Mussels and Clams (Bivalvia)." Bivalvia. N.p., n.d. Web. 26 Mar.
2014. <http://www.molluscs.at/bivalvia/index.html?/bivalvia/main.html>.
Morton, Brian. "Food and Feeding." Encyclopedia Britannica Online. Encyclopedia
Britannica, n.d. Web. 26 Mar. 2014.
<http://www.britannica.com/EBchecked/topic/67293/bivalve/35739/Food-andfeeding>.
"Water Encyclopedia." Bivalves. N.p., n.d. Web. 26 Mar. 2014.
http://www.waterencyclopedia.com/Bi-Ca/Bivalves.html
"Mollusks." Mollusks. N.p., n.d. Web. 26 Mar. 2014.
<http://www.mbgnet.net/salt/oceans/animals/mollusk.htm>.
Madrigal, Alexis C. "Did You Know Scallops Have *Eyes*? Me Neither, but Look."
The Atlantic. Atlantic Media Company, 28 Mar. 2013. Web. 01 Apr. 2014.
<http://www.theatlantic.com/technology/archive/2013/03/did-you-knowscallops-have-eyes-me-neither-but-look/274469/>.