Red pigment epithelium of fish eyes

Abstract

The eyes of characins (Characidae), pike, pickerel (Esocidae) and wrasses (Labridae) have a red pigment epithelium. There is no melanin, the epithelial cells containing red particles (erythrosomes). These are tiny cylinders in the cell processes, and spherules in the cell bases. In characins and pike, the red cylinders participate in retinomotor activity. Cylinders are birefringent and act as waveguides; they transmit long wavelengths (> 550 nm). The red pigment has been extracted and purified. It appears to be the same in the three families. Ultraviolet, visible and infra-red spectra are presented.