Carr, R. K., 1995a. - Biological Sciences

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fishes (WALLS, 1942; NICOL, 1989). Associated with this increase in both relative and absolute
sizes is a concordant change in pupil size (NICOL, 1989). Since the intensity of light varies as
the square of the distance traveled, an increase in eye diameter would require an enlargement
of the aperture to maintain image intensity on the retina. This relationship is found within both
elasmobranchs and osteichthyans (NICOL, 1989) suggesting a common, although independently
derived (GRUBER & COHEN, 1978), pattern among gnathostomes.
Within aspinothoracids, large eyes developed independently several times (Figs. 15B, 16A).
This independence is supported, in part, by differences in the head shiel