The Gertrude fish (Pseudomugil gertrudae) is one of the species of the Rainbowfish. It is commonly found in northern Australia, Indonesia, and New Guinea. The Gertrude rainbow fish is a small but colorful species of the rainbow fish family. 

Unlike a lot of fishes, it is not widespread and comes from streams in about five localized areas. They are often found in aquariums because of their general peaceful disposition and they are popular in freshwater aquariums.

Gertrude fish is also referred to as spotted ‘blue-eye’ fish. Once you see the fish you will find out why it is called spotted blue-eye fish. This is because even though it is small, it has bright fluorescent blue eyes which are very visible and makes it easy to be spotted.

The males have an overall yellow-green color and the female an overall orange blush which is deeper at the tail. The males have bright yellow wings like pectoral fins. The dorsal and pectoral fins are very feather-like and the female has shorter fins. Both the male and female Gertrude fish are covered with spots. The males are generally more colorful than the females.