Phylum Mollusca has a reduced coelomic cavity. Mollusca is one of the most diverse groups of animals on the planet, with at least 50,000 living species. Some characteristic features are
- They are bilaterally symmetrical.
- The body is soft and unsegmented.
- They have tissue-system grade of body organization
- Sense organs consist of eyes, statocysts, and receptors for touch, smell, and taste.