Image of the Day: Coral Fluorescence

ABOVE: The coral Echinophyllia aspera shows off its green glow.
SHUNICHI TAKAHASHI

As a means of recruiting symbiotic partners, corals send out a beacon of light that draws in algae passing by, scientists reported yesterday (January 21) in PNAS. In lab experiments, they showed that the alga Symbiodinium moves toward Echinophyllia aspera coral emitting light from its green fluorescent protein, and in the field, traps painted with a green fluorescent dye likewise attracted the alga. 

Y. Aihara et al., “Green fluorescence from cnidarian hosts attracts symbiotic algae,” PNAS, doi:10.1073/pnas.1812257116, 2019.