Fish with eyes that made scientists look twice

“Many species from the deep ocean have what we call a multibank retina, where these rod cells are stacked in layers, usually between two to six layers,” Dr De Busserolles said.

“But these fish from the reef, they have many more banks, sometimes an extreme number of banks, up to 17 layers in some cases.”

Dr De Busserolles said it was not clear why fish that spent much of their lives in shallow water would need such elaborate eyes for seeing in the dark.

The family of fish, known as holocentrids, are often out at night and retreated to dark corners during the day, but other fish have similar habits and do not have multibank retinas.

“There’s two main theories for why they would have this adaptation – one is that it would allow…