Camera power is supplied from a boat or from shore over a coaxial cable, which also returns the video signal. Illumination at night is provided by waterproof infrared illuminators. During daylight hours, ambient light provides ample illumination for video recording, even on overcast days. Cameras are positioned to view sea anemones or coral heads inhabited by various species of damselfish, which are abundant inhabitants of coral reefs worldwide. Our observations have greatly enhanced our understanding of the behavior of young damselfish.
Settlement occurs only at night.
Settlers appear to locate sites by olfaction. Predators frequently visit corals and anemones both day and night, but virtually all deaths from predation occur at night when damselfish are inactive and sheltering in the coral or anemone, not during the daytime when they are feeding in the water column. Aggressive interactions with other fish that result in movement to the edges of the shelter cause smaller and younger individuals to become vulnerable to predation.