Potential ultraviolet vision in pre-settlement larvae and settled reef fish--a comparison across 23 families.

After hatching, larvae of coral reef fishes experience a pelagic phase during which they are diurnal planktivores. It has been suggested that ultraviolet (UV) vision is beneficial for the detection of planktonic prey. Aims were therefore to investigate whether ocular media of pre-settlement reef fish differ from those of respective adults, and whether larvae have UV-transparent ocular media required for UV vision. The ocular media of 84 pre-settlement and 98 adult species belonging to the same families were measured and compared. We suggest that adult lifestyle rather than planktivory in general shapes the ocular media properties of pre-settlement larvae.