How do flatworms, roundworms, and segmented worms differ from each other?

1 Answer
Aug 4, 2016

Flatworms, roundworms, and segmented worms are all invertebrates. Some species of each type of worm are free-living, meaning they are not dependent on another organism.Some are parasitic.

Flatworms belong to phylum Platyhelminthes. They do not have a coelom, respiratory system or a circulatory system.Tapeworms flukes are examples of flatworms.

Roundworms are part of the phylum Nematoda. They are bilaterally symmetrical invertebrates.They have a psuedocoelom. Ascaris lumbricodes is the most common human parasite.

Segmented worms are the most complex animals of these three invertebrates. They are placed in Annelida. Segmented worms have a true coelom, a circulatory system and a digestive system.An earthworm is a segmented worm.
http://www.darwinsgalapagos.com/animals/annelida_segmented_worms.htm