A new species of bioluminescent ostracode, Vargula morini from Carrie Bow Cay, Belize, is described on the basis of morphology and mating displays. Every night, males of V. morini produce an elaborate species-specific bioluminescent courtship display in order to attract females. These displays occur over coral or coral rubble, beginning near the sea surface and continuing as a series of rapid flashes produced in a downward direction. A nicothoid copepod was found living within the posterodorsal area of the valves of some V. morini. Scanning electron micrographs of these minute ostracode parasites are presented here for the first time.