Melanotaeniidae: found within northern/eastern Australia, New Guinea, Indonesia and
Madagascar. A beautiful family of colorful fish derived from various habitats i.e., rivers, lakes,
The rearing and raising of offspring. These tiny little specimens are very susceptible to parishing
based on water parameters. Keeping these few things in mind will help in your endeavors of
raising and maintaining colonies long-term.
Tip 1: Temperature (80-82 degrees fahrenheit) I can spawn the adults all day long at 68-73
degrees fahrenheit; unfortunately what makes these fish so challenging is temperature
fluctuations for the offspring.
Tip 2: Feeding - a balanced diet with both live and dry foods. (microworms, vinegar eels, baby
brine, very small daphnia; along with powder food) teaching them to be non-reliant on one food
These spawn in the same manner as a lot of opportunistic egg-depositing species i.e., Killifish,
Characins, Cyprinids, etc. I found the utilization of 100% Acrylic Spawning Mops (I did a whole
article on Spawning Mops) is very productive. The adhesive-bond with the eggs, allow for a nice
attachment to the Acrylic.
I’d recommend obtaining a group of two males and three females; utilizing a 4’ long aquarium
i.e., 55 gallon, 40 Long etc. with bare bottom and sponge filters on either side.
Temperature: 75-82 degrees fahrenheit.
- TDS (Total Dissolved Solids) 160-300 ppm
- PH 7.3-8.0
- GH 120-400 ppm
- KH 100-250 ppm (recommended *100-120 ppm)
A Spawning Mop on either side above the sponge filters.
Condition with a balanced diet of carbohydrates and proteins for 3-4 days. Utilizing White
Worms, Mosquito Larvae, Microworms, Daphnia, Brine Shrimp etc. will promote and inhibit
spawning. Keeping the designated system around 75-82 degrees fahrenheit is plenty sufficient.
On day 3 or 4 provide a 20% RODI water (Reverse Osmosis Deionization) change in the
evening about an hour before the lights go out.
Check the spawning mop the next morning for eggs. If you identify several eggs (20 or more),
pull the mop and replace with another. If there’s less than (20 eggs) leave it alone; wait another
24 hours and check again.
Methods to Hatching
From testing several methods over the years; which includes but not limited to the following:
Hydrogen Peroxide, Methylene Blue, Malachite Green etc. The one for which I’ve found to be
the absolute most effective, when artificially rearing and raising: Ich X. During the embryo
development there’s many factors to keep in mind, let’s take a look at some key factors.
Key Factors to Embryo Development
- Temperature - 80-82 degrees F
- GH / KH - Utilizing pre-dechlorinated tap water i.e., Grand Rapids, MI | Wyoming, MI etc. is sufficient.
- RODI- causes acidification for many embryos dependant upon the Genus.
- Utilization of too much chemical additives, such as the above mentioned i.e., Methylene Blue, Ich X, etc. will cause a calcification effect; which will suffocate the embryos.
Pull each egg (yes, you heard me correct) from the spawning mop, utilizing tweezers. Get
underneath each one carefully and transfer over to a deli cup; which contains the
pre-dechlorinated tap water and a couple drops of Ich X. Again, a couple drops NOT too much
as this will cause a calcification effect and resulting in suffocation of the embryos. Have the
water within deli cup just slightly tinted blue.
Place the deli cup; which will contain 3/16” holes cut in the lid, within a floating container of a
designated system at 80-82 degrees. You do NOT need any arriation.
Leave deli cup for about 7-14 days; during which time you’ll begin to identify embryo
development and once you’ve identified hatching of the embryos, you can then begin to transfer
the offspring to their rearing and raising set-up.
Rearing & Raising
I have developed a very specific method for raising Rainbowfish (see photo). Once they’ve
raised for approximately one month within the holding tray, I’ll then move them to a 10 gallon
aquarium with sponge filter. The 10 gallon aquarium will be the same water parameters as the
adults and maintained at 80-82 degrees. After approximately one month within the aquarium, I’ll
then begin to slowly reduce the temperature to 78 degrees fahrenheit and then to room
temperature; which can range from 72-75 degrees fahrenheit. This is all part of the conditioning
and acclimatizing stage I do with ALL my specimens of various Genus.
The specific material for which is utilized within the tray is Sun Guard Window Screen. (100%
Acrylic) The holes within the screen are very fine; which makes this an optimal choice! The toy
organizer (tray) fits perfect on top of several sized tanks i.e., 55 gallon, 60 gallon, 40 long etc.
They simply rest on the trim of tank. Add a single airline tube (NO airstone) within the tray,
providing some turn-over and water flow.
- Powdered foods (Proteins and Carbohydrates)
- Brine Shrimp
Rainbowfish are a beautiful and hardy specimen; however the challenge and patience to
sustainably rear and raise offspring is well rewarding. If you implement some of the
aforementioned you’ll be successful BUT patience is key with your Rainbowfish breeding