zooxanthella

noun

1. (archaic)Any of the yellow pigmentary particles, or minute corpuscles of yellow coloring matter, found in certain radiolarians.
2. Any of various typically yellow-brown dinoflagellates (originally grouped as genus Zooxanthella) now assigned to the genera Symbiodinium and Amphidinium, notably found in coral reefs.

   “One genus, the zooxanthellae, live in symbiosis with tropical corals and other animals including clams, jellyfish and nudibranchs, providing in some cases as much as 90 per cent of the nutrients the anima needs in return for a safe home.”

   “The zooxanthellae produce carbohydrates, via photosynthesis, and the polyps harvest these carbohydrates, much as farmers harvest corn.”