Hydrozoans
From coraldigest
Hydrozoans
Description
- Sub-group of Gnidarians
- Polyp and Medusa life stages
- Polyp is stationary and buds free floating reproductive Medusa.[1]
- Huge diversity of body types and life cycles
- Often develop colonies, which can take many different forms.[2]
- Coral-like (fire corals)
- Unlike true corals which consist of many cells of an individual animal, Hydrozoan corals consist of individual members called Zooids that together function as a colonial animal.[3]
- Free floating (jellyfish-like)
- Resemble jellyfish, actually a colony consisting of multiple groups of mature Medusa
- Coral-like (fire corals)
Distribution
- Found in every ocean around the world
- Almost entirely in salt water
Symbiotic Relationships
Reef Building
- Much like the Anthozoans, Hydrozoans often create a calcium enriched skeleton during their polyp stage
- Although they are so similar, it is believed that this calcification is a result of convergent evolution as opposed to an ancestral trait
References
- ↑ http://animaldiversity.ummz.umich.edu/accounts/Hydrozoa/
- ↑ http://www.ucmp.berkeley.edu/cnidaria/hydrozoa.html
- ↑ Wood, Rachael “Reef-Building Sponges” American Scientist , Vol. 78, No. 3 (May-June 1990): pp. 224-235