Characteristics Of Phylum Annelida. They have homonomous metamerically segmented body. All annelids are bilaterally symmetrical, with an elongated cylindrical body shape divided both externally and internally by regular, linear series of segments.

Ziser lecture notes, 2015.10 1817 live in mucus tubes in or near low tide; These are, in general, aquatic, freshwater or marine, some terrestrial and tubicolous. Larva, when present is a trochophore is characteristics in case of indirect development, while in others this stage is passed through development.

Phylum Annelida Digestive System. The annelids are a large phylum for the organisms ringed worms. They are all triploblastic (containing three different segments) and bilaterally symmetrical.

The majority of leeches live in freshwater environments, while other species can be found in terrestrial and marine environments, as well. Annelids have a complete digestive system with a mouth and anus. Annelids have a complete digestive system with a mouth and anus.