Abstract: The invention relates to methods, compositions and apparatuses, such as squirt guns and of the water emitting devices, that eject a flow of aqueous fluid having visible bioluminescence, providing "glow-in-the dark" emissions. The devices contain a population of a mechanical stress-stimulatable bioluminescent organisms, such as Pyrocystis species such as lunula and fusiformis, in suspension in a fluid. The fluid luminesces when ejected from an aperture of the device. The devices may also include a fluid flow generator, such as a mechanical pump, capable of inducing the flow of the fluid through the flow path and a trigger or valve capable of activating said fluid flow generator. In addition, the invention provides containers for viably storing populations of the bioluminescent organisms, methods and media for culturing and diluting the organisms, and kits of an emitter, a storage apparatus, suitable bioluminescent organisms, and culture media.