- Cestodes belong to the phylum
Platyhelminthes of the larger animal kingdom and are more commonly
known as flatworms. Members of this phylum do not have a respiratory
or circulatory system and the majority are parasitic. However, some
free-living species are found within the class Turbellaria.
- Cestodes a.k.a. tapeworms are made up of two parts:
a scolex and a strobila. The strobila consists of a series of connected
proglottides with the most posterior gravid segments equiped with
both female and male reproductive parts. The structure of the scolex
varies among the different species in this class but, generally,
it consists of four peripheral suckers surrounding a centrally placed
- All cestode species are parasitic and require an intermediate
host to complete their life cycle except for Hymenolepis nana.
Characteristic of species found in this class are thier lack of
complete digestive systems. As a result, all adult cestodes reside
in the small intestine of their hosts.
- Other common cestodes include D. latum, T. solium, and Echinococcus.