Bigeye

Photo: Euan Thomas · CC BY-NC

Crescent-tail bigeyes pack the cave chambers of Erscotts Hole in dense, shimmering schools, their large eyes adapted for the low-light conditions of cavern environments where they spend daylight hours resting before dispersing to feed on zooplankton at night. Their ruby-red coloration, which appears grey-pink in the cave's filtered light, is a deep-water adaptation that makes them cryptic to predators in dark environments.