What is meant when it is said that beings of the phylum Annelida are vascular beings? From which other phyla of the animal kingdom does this feature differentiate them?
The classification of these beings as vascular beings means that they have a circulatory system, with vessels that distribute substances throughout the body. Poriferans, cnidarians and flatworms do not have a circulatory system. In nematodes there is circulation of gases and nutrients through the pseudocoelom fluid.