Examples of two species of nocturnal reef fish surveyed in this study: Myripristis berndti (A) and Priacanthus hamrur (B).

The large eye to body length ratios of these two species (M. berndti: 0.15; P. hamrur: 0.11) give evidence of their nocturnal lifestyle. Like many nocturnal fish, M. berndti and P. hamrur both dramatically increased in abundance at Tabuaeran where large daytime active predators were less abundant. Example diurnal fish Chlorurus sordidus (C) and Epibulus insidiator (D) exhibit the smaller eye to body length ratios (C. sordidus: 0.05; E. insidiator: 0.05) that are more characteristic of diurnal reef fish. These species were among the diurnal prey fish taxa whose abundance showed negative or weak responses to predator depletion.