An apparatus for selectively affecting the behavior of elasmobranch fish such as rays, skates and sharks, with electromagnetic waves. The apparatus comprises a power source, an electrical circuit capable of generating a selected voltage, current, and alternating frequency, an antenna capable of receiving the converted power from the electrical current and transmitting the converted power as an electromagnetic field, and an optional control means disposed between the power source and the antenna. In operation, this apparatus generates and transmits electromagnetic waves whose effects are perceivable by certain aquatic elasmobranch fish, which can be adjusted to cause a selected behavior, such as attraction or repulsion. The characteristics of the emitted electromagnetic waves can be controlled and changed to fit the desired needs. The apparatus can be self-contained or part of a larger system, and can be incorporated into a variety of devices.