X-ray induced behavioral reactions and detection mechanisms in the shrimp

Abstract

Red Ghost Shrimp, Callianassa californiensis, were shown from behavioral and electrophysiological studies to respond to ionizing radiation. When exposed to X-rays at 52 R/sec, the majority of intact animals could detect and avoid further irradiation by escaping into a shielded section of the test chamber. Animals continued to display escape responses after removal of eyestalks and antennae. Significant avoidance activity also occurred with partial-body exposure and indicated the existence of a radiation-sensitive receptor on the abdomen. Electroretinograms elicited by beta- and X-radiation sources corresponded closely with the waveforms produced by visible light stimulation. Electroantennograms were recorded from isolated antennules following stimulation with glutamic acid, beta-, and X-radiation. Biphasic on-off phases were recorded with an intermediate phase present during the longer duration exposures. Similarly, bioelectrical potentials were recorded from swimmeret preparations with exposure to beta- and X-radiation. The electrophysiological evidence indicates that the eye, antennules, and possibly chemoreceptors on the abdominal segments serve as routes for detection of ionizing radiations.