2 Melanotaenia sahulensis “Skull Creek”, a small, peaceful, and vibrant freshwater rainbowfish native to northern Australia (Cape York Peninsula) and southern New Guinea.  Typically between 2.5 - 4" in length, with brilliant blue-green sheen, silvery-grey body, and distinctive colored fins.

Difficult to photograph and totally faded when I got them into a photography tank.  The first picture is from the Internet with the fish in full color.