Melanotaenia lacustris, the Lake Kutubu Rainbowfish from New Guinea, aka Turquoise Rainbowfish. Tank raised from LFS stock. My fish are blue and white, and show no yellow as in the pics in the reference. Males are bigger, taller and more colorful than females, reaching about 4 inches. Rainbowfish are peaceful on the whole, but will eat smaller fish and their fry. Displaying Rainbowfish over dark gravel and a dark background will enhance the intensity of their colors.