In subsequent citations, only use the first author's last name followed by et al. in the signal phrase or in parentheses. (Kernis et al., 1993). In et al. , et should not be followed by a period.
Transcript of Hammerhead Shark Eyes. Structure of Eye. The structure of a hammerhead sharks eye is very similar to the human eye, they have a cornea, lens, retina, pupil and iris. Their retina has both cone and rod cells, which means they can see light, dark, and colours.
Hammerhead sharks are any of eight species of sharks in the family Sphyrnidae, in the class Chondrichthyes, which also includes rays and chimaeras. The flat, broadly T-shaped head is on rare occasions called a cephalofoil. It looks like a double-headed hammer or ax, with one eye and one nostril at each end.