Reproduction
- They are advanced invertebrates. Echinoderms can reproduce asexually and sexual, evolving eggs by spermatozoa. Sea stars and cucumbers produce asexually. Sexual reproduction involves the external fertilization of eggs by spermatozoa. The fertilized eggs develop into planlctonic larvae. The larvae go through two stages called bipinnaria. They are bilaterally symmetrical and have bands of cilla used for swimming and eating. Asexual reproduction in Echinoderms usualy involves the division of the body into two parts and the reproduction of missing body parts.