What is the Difference Between Phylum Annelida and Echinodermata?

The key difference between Phylum Annelida and Phylum Echinodermata lies in their symmetry, body structure, and habitat. Here are the main differences between the two phyla:

1. Symmetry: Phylum Annelida includes bilaterally symmetrical segmented worms, while Phylum Echinodermata includes radially symmetrical marine organisms.
2. Body Structure: Annelids are segmented worms, and they are true coelomates, meaning they have a body cavity lined with mesothelium. Echinoderms, on the other hand, are enterocoelomates, which means their body cavity is derived from the gut.
3. Habitat: Annelids are found in both terrestrial and aquatic habitats, while echinoderms are exclusively marine organisms.

Both phyla are part of the Kingdom Animalia and include invertebrate species with great diversity. Additionally, they are both non-chordate phyla and coelomates.

Comparative Table: Phylum Annelida vs Echinodermata

Here is a table comparing the differences between Phylum Annelida and Phylum Echinodermata:

• Body Symmetry: Phylum Annelida consists of segmented worms that show bilateral symmetry, while Phylum Echinodermata includes organisms that exhibit pentamerous radial symmetry.

• Body Segmentation: Annelids are segmented worms, whereas Echinoderms are non-segmented.

• Organ Systems: Annelids have simple organ systems, including a straight alimentary canal, nephridia, closed circulatory system, and double ventral nerve cord. In contrast, Echinoderms have complex organ systems.

• Coelom: Annelids have true coeloms, while Echinoderms have pseudocoeloms.

• Examples: Examples of Annelida include earthworms and leeches, while Echinodermata examples include starfish, sea urchins, and sand dollars.