1. Of scyphozoans, hydrozoans, and ctenophore, which group is more likely to form large blooms are capable of disrupting ecosystems? 2. Explain the evidence that suggests that cnidarians and ctenophores are diploblastic. Then, describe the evidence that suggest development in ctenophores may be triploblastic. 3. Describe the gastrovascular cavity structure in the following: hydrozoan, scyphozoan, and anthozoan polyps. Which one is probably the most efficient at digesting food and absorbing nutrients? .