Current thinking on how the Toxoplasma gondii parasite invades its host is incorrect, according to a study published today in Nature Methods describing a new technique to knock out genes. The findings could have implications ...
Definition. Coral bleaching is a process whereby the coral colonies lose their colour, either due to the loss of pigments by microscopic algae (zooxanthellae) living in symbiosis with their host organisms (polyps), or because these zooxanthellae have been expelled.
By night the polyps feed on plankton by capturing it with their tentacles. If the rate of photosynthetic production is too high, corals have the ability to control the amount of zooxanthellae in their tissues by expelling it; this is known as coral bleaching, which is normal.