The phenomenon of fish communication, via hydronic radio waves, is both perplexing and important to the biologist. It has been found through my research that fish definitely possess the ability to produce hydronic radio waves. Hydronic signals are neither sonic nor electrical, but are receivable on a submerged dipole antenna. No signals are received in the absence of fish and each species emits signals characteristically different from other species in carrier frequency, pulse duration, and intensity. Incidence of signals per unit time varies with species of fish, tidal conditions, lighting conditions, and temperature conditions.