Spectral sensitivity, luminous sensitivity, and temporal resolution of the visual systems in three sympatric temperate coastal shark species.

We used electroretinography (ERG) to determine spectral and luminous sensitivities, and the temporal resolution (flicker fusion frequency, FFF) in three sympatric (but phylogenetically distant) coastal shark species: Carcharhinus plumbeus (sandbar shark), Mustelus canis (smooth dogfish), and Squalus acanthias (spiny dogfish). Spectral sensitivities were similar (range ~400-600 nm, peak sensitivity ~470 nm), with a high likelihood of rod/cone dichromacy enhancing contrast discrimination. Spiny dogfish were significantly less light sensitive than the other species, whereas their FFF was ~19 Hz at maximum intensities; a value equal to that of sandbar shark and significantly above that of smooth dogfish (~9-12 Hz).