The fireworm Odontosyllis phosphororea is a local polychaete worm that inhabits the bays of San Diego. They normally live in parchment tubes that are attached to hard surfaces. But every summer within a few days of the quarter moon, these tiny worms emerge and present a spectacular display of mating while emitting a bright blue-green light.

The females come first to the surface, releasing eggs in a glowing cloud of mucus. The males, which have large eyes, are attracted to the glow and then spawn. The entire process takes half an hour. More information about the bioluminescence of this worm is provided by Drs. Deheyn and Latz.

Mary Rose, a retired naturalist from Birch Aquarium at Scripps Oceanography, has been instructing the public on this hidden mystery since 2010. The public is invited to come to De Anza Cove boat launch ramp at 7 pm on September 21, 2023, when Mary will explain the natural history of this worm and discuss other types of bioluminescence.