Sun-Animalcule plankton get their name from their tendency to emit light in a sphere around them.
The plankton begin as eggs and gradually grow, emitting light and fascinating sounds throughout their entire life cycle. The sounds they make will change as they grow from infancy to maturity, growing very quickly until they disappear completely. Sun-Animalcule plankton only emerge in the morning, noon and evening. They lose strength as the night wears on; that's when the crescent-shaped Falcato plankton take their place. The pitch of the plankton changes depending on where they grow.