pupillary opercula

the irregular lobe(s) of the upper iris which permit it to decrease the size of the pupil by extending the lobes, giving the pupil an irregular shape. May shade or camouflage the eye, e.g. Ogcocephalus, Halieutichthys (Ogcocephalidae); Raja clavata (Rajidae); Uranoscopus scaber (Uranoscopidae)