Retinal tapetum lucidum: a novel reflecting system in the eye of teleosts.

A new type of tapetum lucidum has been found in eyes of bony fishes (teleosts). It is retinal, lying in the processes of the pigment epithelial cells; it has a white appearance and reflects light diffusely. The cell processes are loaded with highly refractile lipid particles; as examined by electron microscopy these are about 400 nanometers in diameter, spherical, and homogeneous. This tapetum lucidum has been found in seven families of teleost fishes occurring in inshore waters and rivers of South Texas, all of which have high turbidity; the correlation indicates a role in dim-light vision.