Lecture 9 (Symbiotic Dinoflagellate) Flashcards
Symbiotic dinoflagellates
Single-celled organisms that live in a mutualistic relationship with other organisms, providing each other with nutrients and energy
Zooxanthellae is an example of a ______________
dinoflagellate
There are _____ different strains of Symbodinium sp. (Zooxanthellae)
80 (one for every need of corals)
Why do zooxanthellae interact with corals?
1) Protection
2) A constant environment
3) Nitrates, phosphates, ammonia
Why do polyps interact with zooxanthellae?
1) Nutrients from photosynthesis
2) Calcification
3) Zooxanthellae removes the CO2 that is an end product of calcification
What are the 3 types of symbiosis?
1) Parasitism
2) Commensalism
3) Mutualism
Algal-invertebrate symbiosis
1) Most hermatypic corals are symbiotic with zooxanthellae as the dinoflagellate
2) Soft corals, jellyfish, giant clams, sponges, protists, and nudibranchs also use this symbiosis
3) Cyanobacteria co-exist with zooxanthellae in Montastrea cavernosa
T/F: Some zooxanthellae show specificity for some corals
T (different zoo have certain temps or other parameters)
How can polyps control the amount of photosynthesis that occurs?
By changing the distance that they extend their tentacles (able to “hide” in shade)
Do corals digest zooxanthellae?
No, but they recognize them as “no problem” (can digest and then eject them)
How can certain coral species better adapt to changing environments and light intensities?
By having more than one strain of zooxanthellae
_____ ______ can provide their planula with a starter culture
Coral brooders (reproduce sexually through internal fertilization and larval development)
T/F: Broadcast spawners (external fertilization) must incorporate free-living dinoflagellates
T
What causes a bleaching event?
A stressor
Under stressful conditions, coral will expel the _____________
zooxanthellae
