Characteristics of Playthelminthes
Platyhelminthes also known as 'flatworms' are a phylum of triploblastic acoelomate invertebrate animals. The word platyhelminthes comes from the Greek words 'platy' meaning flat and 'helmins' meaning worm. Their worm like bodies are soft, unsegmented, dorsoventrally flattened with bilateral symmetry, and resemble ribbons. Their flattened shape helps them to obtain oxygen and nutrients by diffusion through their body membranes. Some of these species are carnivorous, while the rest are parasitic. Nearly all are aquatic, mostly marine and few freshwater. Some are even terrestrial.
Phylum Platyhelminthes comprises 34,000 known species which are categorized under four classes: Turbellaria, Monogea, Trematoda, and Cestoda. Class Turbellaria comprises flatworms that are ciliated and free living, whereas members of class monogea are ectoparasitic (live outside the host body) and constitute monogenetic flukes. Class Trematoda comprises common flukes and the fourth class Cestoda comprises endoparasitic (live within the body of the host) worms, which are also known as tapeworms.
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Platyhelminthes also known as 'flatworms' are a phylum of triploblastic acoelomate invertebrate animals. The word platyhelminthes comes from the Greek words 'platy' meaning flat and 'helmins' meaning worm. Their worm like bodies are soft, unsegmented, dorsoventrally flattened with bilateral symmetry, and resemble ribbons. Their flattened shape helps them to obtain oxygen and nutrients by diffusion through their body membranes. Some of these species are carnivorous, while the rest are parasitic. Nearly all are aquatic, mostly marine and few freshwater. Some are even terrestrial.
Phylum Platyhelminthes comprises 34,000 known species which are categorized under four classes: Turbellaria, Monogea, Trematoda, and Cestoda. Class Turbellaria comprises flatworms that are ciliated and free living, whereas members of class monogea are ectoparasitic (live outside the host body) and constitute monogenetic flukes. Class Trematoda comprises common flukes and the fourth class Cestoda comprises endoparasitic (live within the body of the host) worms, which are also known as tapeworms.
Read more at Buzzle: http://www.buzzle.com/articles/characteristics-of-platyhelminthes.html