Whale Sharks Have Denticles on Their Eyes

Because a whale shark has relatively small eyes it was assumed that it relied less on vision than its other senses. Although a whale sharks is able to retract its eyeballs, unlike many species of shark it lacks a nictitating membrane to protect its eyes.

A recent study suggests that vision is important to whale sharks and their eyes are highly protected. Scientists from the Okinawa Churashima Research Center in Japan, discovered numerous dermal denticles (referred to as eye denticles) are distributed on the eye surface around the iris. These eye denticles are designed for "abrasion resistance" and are morphologically distinct from denticles distributed over the rest of the shark’s body.

Tomita T, Murakumo K, Komoto S, Dove A, Kino M, Miyamoto K, Minoru T. (2020) Armored eyes of the whale shark. PLoS ONE 15(6): e0235342. https://doi.org/10.1371/journal.pone.0235342