1. Fertilization is external, producing free - living planula larva.

2. 24 Fertilization is external, producing free - living planula larva.

3. Cnidarians often have a life cycle consisting of planula larva, polyp, and medusa stages.

4. In Anthozoans, the typical life cycle begins with the development of fertilized eggs into free-swimming larvae known as planula, which in turn transform into polyps that can undergo asexual reproduction to produce new polyps or form colonies.

5. Definition and Origin of Cnidaria: Diploblastic metazoans with radial symme­try, tissues but rarely organs and a single central body cavity with mouth and tentacles but no anus, and the stinging cells or nematocysts, and with ciliated planula larva, called Cnidaria.