A pair of Glossolepis pseudoincisus, the Millenial Rainbow
Although they are not often available, in my opinion the Millenium Rainbow is one of the most beautiful of all rainbowfishes. Its’ intense blood-red color seems even brighter than that of the Red Rainbow, Glossolepis incisus, a similar and very beautiful popular fish. Its’ scientific name is thought to be Glossolepis pseudoincisus, although that has yet to be finally confirmed. Glossolepis pseudoincisus was first discovered, collected, and described in 1954 by M. Boeseman from the Tami River which runs into Lake Sentani, West Papua. No more collections of this fish were reported in nearly 50 years! In January 2001 (hence the name “Millenium”), Heiko Bleher collected this fish from Lake Ifanten, an isolated crater lake near Lake Sentani. This is also the general region that the Red Rainbow comes from. The Millenium Rainbow differs from the Red Rainbow in several respects: it doesn’t get as large, has a more compact body shape, the scale pattern is different, and it gets the red coloration after 3 months, whereas the Red Rainbow may take up to a year. The intensity of the red coloration in both these fish can vary with age, health, temperature, and mood.
The Millenium Rainbow has a good appetite and will eat just about any foods including flake, frozen, and live. Some spirulina flake food should be included in their diet, as well as including a variety of foods for the healthiest fish and best color. These fish need a good sized tank if you are keeping a group of them. Adults can get to 4 inches and they are a very active fish, so swimming room is needed. 70-79 degrees temperature is a good range and the best color seems to exist at the low end of that. Clean water with a medium hardness and a PH of 6.5 to 8.5 keeps them happy. They usually inhabit the top or middle levels of the aquarium and are good jumpers, so keep them covered. They are not aggressive and should not be put in the same tank with aggressive species.
Millenium Rainbows are more sensitive to water pollution than the Red Rainbow, and I lost my first pair from not making adequate water changes. With the second pair I obtained, I found out that the male can be quite aggressive toward the female, and he eventually killed her. I had collected and picked many eggs from the mops and tried to hatch them in pans with light areation, as I have done with success in the past. They would eye up, but eventually die and I couldn’t get any to hatch. I tried methylene blue, hard water, soft water, and even added salt to the water but still none hatched. My middle name could be “Persistence”, sometimes to my detriment, but I went out and bought another pair at auction. I managed to put them in a clean tank with plenty of cover for the female and began getting more eggs in the mop. I needed to try something different, so I placed the mop with eggs in a 2 gallon jar with clean water and light aeration (sometimes the most basic principles take time to sink in!). Voila! Tiny fry began hatching out after one week and appearing at the surface of the water. APR and Liquifry were the first foods used and the fry grow slowly. Reports are that these fry are difficult to keep alive until they are about 2 months old, which may be reason for their scarcity and higher price.
I recommend that if you find the Millenium Rainbow available at auction or in a shop that you obtain some. Their great beauty and challenge to keep and breed offers many rewards.
6-day old Millenial Rainbow fry under 100 power microscope