Worlds Smallest Fish

Paedocyprisis (only 7.9mm long) -- Scientists claims to be the smallest known fish in the world. The tiny, see-through Paedocypris fish have the appearance of larvae and have a reduced head skeleton, which leaves the brain unprotected by bone. They live in dark tea-coloured waters with an acidity of pH3, which is at least 100 times more acidic than rainwater.