Phylum Annelida is a very broad phylum belonging to the kingdom Animalia. The Annelids are found in aquatic as well as terrestrial environments. These are bilaterally symmetrical invertebrate organisms.
- The Annelids are coelomate and triploblastic.
- They exhibit organ system level organization.
- Their body is segmented.
- They respire through their body surface.
- Nephridia are the excretory organs.
- They have a well-developed circulatory and digestive system.
- Example Earthworms, and leeches
Arthropoda is the largest phylum of all living organisms and having members with a particular exoskeleton and segmented bodies. Arthropoda is the largest phylum with about nine lakh species.
- The body is triploblastic, segmented, and bilaterally symmetrical.
- They exhibit the organ system level of organization.
- The body is divided into the head, thorax, and abdomen.
- Their body has jointed appendages that help in locomotion.
- The coelomic cavity is filled with blood.
- They have an open circulatory system.
- Example: Prawn, cockroach