Zooxanthellae

Physiology

a. Physical characteristic 1. single-celled mixotrophic microorganisms 2. share the same spherical form that enables them to live within coral

b. Genetic characteristic 1. part of a group of dinoflagellates Flagellated Thecal Plates 2. Zooxanthellae is the name given to a wide array of different algae of the genus Symbiodinium

d. Behavior 1. live in the tissues of other organisms Cnidarians (Coral Polyps, Jellyfish) Nudibranchs (Sea Slugs) 2. Under-represented in the water column

Mutualistic Relationship with Coral Reefs

a. Photosynthesis 1. Corals provide a safe environment and compounds needed for photosynthesis 2. Zooxanthellae provide food (nutrients) for the coral to use in order to secrete calcium carbonate skeleton 3. Highly efficient exchange of nutrients 4. Relationship has lasted for more than 200 million years b. Sugar/Carbohydrate Export c. Amino Acid Export

Environmental Impact & Coral Bleaching

a. Bleaching occurs when environmental stress adversely affects the mutually beneficial relationship between the host organism and its zooxanthellae.

Sources

http://oceanservice.noaa.gov/education/kits/corals/coral02_zooxanthellae.html (accessed on 2/23/13)

http://coralreef.noaa.gov/aboutcorals/coral101/symbioticalgae/ (accessed on 2/23/13)