Monday, March 16, 2009
What's odd about this small (40cm) deepwater shark? Well, in addition to light-emitting photopheres on its skin, a common adaptation of deep-sea predators out to lure prey, Centroscyllium ritteri has them on the undersides of its upper eyelids. Why would a fish "want" (evolutionarily speaking) to cast light into its own eyes? Would it want to light up its eyes when the lid rolls back to startle a predator? That doesn't seem to work. Neither, really, does any other theory I've read.