Donut, No Worms

Donut of worms (tentatively Raion donut) without visible worms.

1. Normal state Just as terrestrial corals contain photosynthetic partners called zooxanthella, the donut contains a population of predatory worms.

2. Disturbed state Just as terrestrial corals sometimes expel their partners when under stress, this donut raion has discharged or killed its population of worms. (Alternatively, they have left in search of a better host.) This may be a reproductive strategy, a defensive reaction to the worms turning on and feeding upon the sponge, or a response to environmental stress.

Assessment: unclear how long the donut can survive without its primary food supply. Terrestrial corals survive only days to weeks after bleaching.