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.
Coral bleaching happens when coral polyps, the animals that build corals, shed the algae (zooxanthellae) that give them their color, and which are necessary for their survival. The coral is then white in appearance. Coral scientists are not sure what causes coral bleaching, but warming water is the most likely culprit. Corals in the Caribbean and Florida have bleached when sea surface temperatures rose and were higher than the mean sea surface temperature for as little as one month.