The forktail blue-eye is not only colorful but its unique fin shape draws attention to your aquarium. The scientific name is pseudomugil furcatus and they come from rivers in the Milne Bay Province in Papua New Guinea. As you can see from the pictures the males have colorful fins and the females have little color in their fins. The fins get longer with age making them more interesting.
You can see two more things from the pictures. It is obviouse where the "forktail" name came from, and it is also obvious from the males pectoral fin shape that these rainbows are jumpers.
Thes fish live about 3 years and come from rivers that have lotof plants and trees. They tolerate a wide range of pH from 6.5 to 8. My water is soft but I add 1 teaspoon of Epson salt (magnesium sulfate) and 1/4 teaspoon of deicer (calcium chloride) to their 30 gallon aquarium.
They will spawn in the plants or on wood or other substrate like rocks, but I provide a synthertic yarn mop. The eggs take around 18 days to hatch. I have tried to protect the eggs using methylene blue and then acriflavin added to the water the eggs were in but got no fry. Hydrogen peroxide (3%) at 2 mL/ gallon allowed some eggs to survive and hatch.