Glowing Trio under the Sea: Nitrogen fixer joins algae inside coral

A Caribbean coral that fluoresces orange appears to be the first ever found to contain a symbiotic microbe that converts elemental nitrogen into a biologically usable form, as bacteria in the roots of bean plants do.

The glow of Montastraea cavernosa doesn’t come from the coral tissue itself but from cyanobacteria that take up residence there, say Michael P.