Tapeworms are a type of parasitic flatworms from the class Cestoidia.  They
are the largest of all parasites and may be up to 10 meters long.  They consist of
three main parts:the scolex-the head and attachment organ of the parasite; the
neck-the area of proliferation connecting the scolex to the strobila; and the
strobila-composed of a series of segments called proglottids. These proglottids are
flat, rectangular body segments that eventually break off and are excretedin the
feces of the host.  They contain the tapeworm eggs.  A tapeworm may have over
4000 proglottids and can release up to 1000000 eggs into the host every day!  The
tapeworms are usually white or yellowish in color.  The adults live in the
intestines of vertebrates, attached to the intestinal wall and may live up to 25 years
inside the host.  The most common types of tapeworms infecting humans
are:Taenia Solium, Taenia Saginata and Diphyllobothrium latum. 

TAENIA SOLIUM (PorkTapeworm )
 This tapeworm is transmitted to humans through the consumption of raw or
undercooked pork that is infected.  Pigs serve as an intermediate host (the eggs are
ingested by the pig and hatch inside its body.The larvae work their way inide the
pigs muscles.  When the pork is eaten, the worms are transferred to the human
host.)  The adult tapeworm measures 2.5 to 3 meters in length and its body may be
composed of 1000 proglottids.  This form of tapeworm infection is usually
asymptomatic, but eggs may be found in stool or around perianal area.  It is
usually treated with the drug, Niclosamide.  Infection is prevented by thouroughly cooking pork.
Lifecycle

TAENIA SAGINATA (Beef Tapeworm)
 This tapeworm is generally very similar to the pork tapeworm.  It is usually
contracted through the consumption of undercooked beef, or sometimes fish, with
cattle as the usual intermediate host.  The adult tapeworm can grow to 6 meters in
length.  Like the pork tapeworm, it is usually asymptomatic, though the host may
experience abdominal cramping.  It can be diagnosed by proglottids found in the
stool and is treated with Niclosamide.  It is prevented with the proper cooking of meat

.

DIPHYLLOBOTHRIUM LATUM (Broadfish Tapeworm)
 The broadfish tapeworm is contracted through the consumption of
undercooked fish that have been infected.  The broadfish tapeworm is a long,
broad tapeworm, usually between 1 and 2 meters in length, though it may grow up
to 10 meters long.  Symptoms include abdominal distension, flatulence, abdominal
cramping and diarrhea.  They appear about 10 days after eating infected fish.
Proglottids may appear in the stool and the infection is treated with Niclosamide,
but, like the other tapeworms, infection is prevented by proper cooking of fish. 
Lifecycle

REFERENCES:
-www.bartleby.com/65/ta/tapeworm.html
-www.path.cam.ac.uk/tjs16/Tapes/Tapes_Gen/human.tapeworms.html
-www.drugbase.co.za/data/med_info/porktape.htm
-www.britannica.com
-www.vm.cfsan.fda.gov/~mow/chap26.html
-www.biosci.ohio-state.edu/~parasite/diphyllobothrium.html
-Elmer R. Noble, Glenn A. Noble, Parasitology, The Biology of Animal Parasites,
Third Edition, 1971

MORE LINKS:
-vm.cfsan.fda.gov/~mow/chap26.html
-www.path.cam.ac.uk/~tjs16/Tapes/Tapes_Gen/human.tapeworms.html
-www.bartleby.com/65/ta/tapeworm.html
-encarta.msn.com/find/Concise.asp?ti=038D7000
-www.epa.gov/gumpo/seast01.html#types
-www.infoplease.com/ce6/sci/A0847833.html
-www,path.cam.ac.uk/~tjs16/Tapes/D.latum.html
-www.biology.iastate.edu/Courses/201L/18.3%20Platyhelminthes/%20tapeworms