Obelia
Obelia is a genus of colonial hydroids in the family Campanulariidae. They are small, colonial invertebrates that are found in marine environments worldwide. Obelia species are common in shallow waters and are often found attached to rocks, seaweeds, and other substrates.
Common Names
Obelia is commonly known as the "white hydroid" or the "bell hydroid" due to its characteristic white, bell-shaped polyps.
Characteristics
Obelia colonies are composed of two types of polyps:
- Hydranths: These are feeding polyps with tentacles that capture and consume small prey.
- Gonophores: These are reproductive polyps that produce medusae, the free-swimming stage of the life cycle.
The colony is held together by a branching, chitinous structure called a perisarc. The perisarc provides support and protection for the polyps.
Environment
Obelia species are typically found in shallow marine environments, often in areas with strong currents. They prefer substrates that are hard and stable, such as rocks, seaweeds, and piers.
References
For more detailed information about Obelia, consult these reliable online resources: