Ultraviolet blocking in the ocular humors of the teleost fish Acanthocybium solandri (Scombridae)

Abstract

The humors of the eye of the pelagic predator Acanthocybium solandri (the wahoo or ono) absorb ultraviolet-A radiation of longer wavelength than that absorbed by the lens. Except for a single juvenile fish, the 50% transmission cutoff for lenses of about 1 cm diameter were of a shorter wavelength than the cutoff for 2–3 mm thick samples of the humors. The lens showed more absorption than the humors below 340 nm but lacked much of the ca. 360 nm absorption found in the humors. Related and ecologically similar fish show the more normal condition, with the lens as the primary short-wavelength filter. The functional significance of this design is obscure.