Hydra and Obelia are cnidarians (species of aquatic organisms) that belongs to the Class Hydrozoa.
Several ways in which Obelia differs from Hydra are;
- Hydra is a predative species that lives on substrates such as wood, while Obelia is a colonial species that lives as polyps on branched frameworks.
- Hydra is found in freshwater habitats, while Obelia is found in marine habitats.
- Hydra undergoes the medusa form in its life cycle, while Obelia undergoes the two forms (polyp and medusa) in its life cycle.
- Hydra has great regenerative powers while Obelia does not have great regenerative powers.