The Row and the type of invertebrate are:
1 Simplest organism in phylum Metazoa; they have tiny pores all over their bodies.- Porifera
2 Aquatic, mostly soft bodied, carnivorous, radially symmetrical with stinging tentacles around their mouths-Cnidaria
3 Segmented bodies, tough external skeleton, cephalization, jointed appendages- Arthropoda
4 Unsegmented bodies with specialized tissues and organ systems, digestive tracts with mouth and anus openings.- Mollusca
5 Soft, flattened, unsegmented bodies that lack a coelom and anus -Platyhelminthes
6 Segmented backs with a ring-like appearance.- Annelida
7 Soft-bodied animals that typically have internal or external shells and complex organ systems.- Echinodermata
Annelida is a phylum of segmented invertebrates that includes worms such as earthworms, leeches, and marine polychaetes.
So, Annelids are characterized by their segmented bodies, each of which contains a coelom (a fluid-filled cavity) and a ganglion (a cluster of nerve cells). Annelids also have a well-developed digestive system, circulatory system, and nervous system.