Page 3 - 2.Lesson Notes-Animalia 2

• Have radial symmetry.
• The animals are usually pentamerous.
• They are triploblastic and have a coelomic cavity.

• They have a water driven tube system for moving forward, helps in
locomotion.

• Examples: starfish, sea urchin, sea cucumber, sea lily etc.

Protochordates

• Protochordata is bilaterally symmetrical and triploblastic.
• In addition to these, they have a notochord that runs along the back of the
animal and separates the nervous tissue from the gut.
• They are marine animals and bridge non-chordates to chordates.
• Porifera to Echinodermata are non-chordates/invertebrates.
• Example: Balanoglossus, also called acorn worm.