Today's featured picture on the Wikipedia main page is of the Priacanthus hamrur, commonly known as the lunar-tailed bigeye or moontail bullseye. This is a species of marine fish found in the Indo-Pacific region, known for its deep, laterally compressed body, very large red eyes, and a crescent-shaped tail. The photograph was taken off the coast of Zanzibar, Tanzania.

You can view the image and read more about the species here.