Platyhelminthes (Greek: (platys) "flat", (helmins) "worm") is a
Phylum within Kingdom Animalia. It is composed of over 34,000 species; notable
members of this phylum are flatworms, tapeworms, and planarians.
Characteristics of Platyhelminths*
Classes Within Platyhelminthes
Non-parasitic and aquatic; named for the turbulence their cilia cause in the water.
Flukes that have only a single generation; parasitize fish.
Flukes which have more than one generation, and go through more than
one host. The Chinese Liver Fluke starts off in
snails, moves to fish, and then attaches itself to the liver of humans
who eat the fish.
The tapeworms. Divided into the scolex, a nightmarish head that attaches itself with suckers or hooks to the host, a neck, and strobila, little packets of eggs that pass in the feces.
Campbell & Reece. "Biology" Benjamin Cummings. 6th Edition, 652-654
Miller & Harley. "Zoology" McGraw Hill. 7th Edition, 156-168
* Characteristics are shared by most members of the
Phylum; there is some level of individual variation. Characteristics
are not noteworthy to the extent that they apply to each member of the
Phylum, but to the extent that they differentiate members from the
members of other Phyla.