Max Size: 15cm

Madagascar Rainbowfish (Bedotia madagascarensis)

The Madagascar Rainbowfish are an excellent fish for the larger community aquarium. They can adapt to a variety of water conditions. Hobbyists often find that the Madagascar Rainbowfish is more cultured than the other Rainbowfish, making it suitable for housing with a broader array of tank mates. They are a schooling fish and seem to fair better when kept in groups of six or more. However, they are generally peaceful with each other and friendly with other fish of similar size and temperament.

The Madagascar Rainbowfish is an easier rainbowfish to care for and breed. However, these fish are better suited to the more advanced aquarist rather than a beginner. Like all Rainbowfish, they require pristine water, meaning frequent water changes are a must to avoid disease and keep them healthy. With a conventional filter and oxygenated water, this fish will be a rewarding addition to your aquarium.

The Madagascar Rainbow fish's body is long and slender with fins that are short but sturdy. The primary body colour is a pale yellowish-brown with silvery scales and a slight blue shine. A prominent, dark blue band runs the length of the fish with a second fainter and shorter bar just below it. The fins of males are black at the very base, fading through white into striking red, and finally ending with a black edge. The female's fins will be transparent or sometimes a subdued version of the male's fins. There are many regional colour variants.


Madagascar rainbowfish
Madagascar rainbowfish
Madagascar rainbowfish
Madagascar rainbowfish
Quick Facts
Scientific NameBedotia madagascarensis
Other NamesRed-Tailed Silverside, Madagascan Rainbow Fish, Zona
Aquarium LevelMiddle - Top
Best kept asGroups 6+
Lifespan5 - 10 years
Water Parameters
Water TypeFreshwater
PH6.5 - 8.5
GH8 - 25
TDS0 - 268
72 - 77℉
22.2 - 25℃


In the home aquarium, the Madagascar Rainbowfish will readily accept most good quality dried foods such as granules, flakes and sinking pellets. These modern food products have been developed to provide all adequate nutrition to maintain your fish's health and dietary requirements.

Providing additional foodstuffs such as live, frozen, and freeze-dried meals such as bloodworm, daphnia, and tubifex once or twice a week will provide additional benefits to your fish's health and well-being but is not a must for this fish.

It should be noted that bloodworms should only be given as an occasional treat and should not be used as the staple diet as they are difficult for fish to digest and can potentially cause blockages.

This fish is an omnivore in the wild, meaning it will consume some vegetable matter. Although most modern fish foods take this into account and include them in their products, you can still supplement your fish's diet with blanched vegetables such as spinach, broccoli, and zucchini. Ensure you do not overfeed your fish and remove any leftovers the following day.

Sexual Dimorphism

It is relatively straightforward to distinguish males from female Madagascar Rainbowfish. In general, adult males are much more colourful and have a greater degree of colour in the fins than females. In contrast, Females are duller and fuller-bodied than males, particularly when gravid.


Breeding the Madagascar Rainbowfish is straightforward once these fish are happily established and settled into your aquarium. You will need a mature pair or group of males and females, along with a spawning mop, preferably floating at the top of the aquarium downwards to the substrate.

Despite spawning year-round, Rainbowfish lay many eggs at the beginning of the rainy season. In addition, temperature increases, and live and frozen foods often encourage spawning.

Check your spawning mops daily for any eggs that have been deposited and either remove the eggs from the mop or, better still, remove the entire mop to avoid contamination of the Rainbowfish eggs.

Tip: Have several spawning mops at hand so you can place a fresh spawning mop into the aquarium while you wait for the eggs to hatch on the other mop/s.

Place the spawning mop with eggs still attached into a separate small cycled aquarium with a sponge filter for flow, and add a few drops of Methylene Blue (Methylene Blue helps prevent fungal infections of eggs).

Your rainbowfish Eggs will hatch within 7 to 18 days, depending on the species and the temperature. We recommend 27°C = 80.6°F for the fastest development of fry.

Once the Rainbowfish fry hatch, they absorb their yolk sacs quickly and become free swimming, moving towards the water's surface. Once the fry reaches the water's surface, you can start feeding. We recommend feeding on Micorworm (the most straightforward live food to culture) and decapsulated brine shrimp egg powder several times a day while being careful not to overfeed and pollute the water column.

After a week or two, you can start to add newly hatched brine shrimp, but this isn't necessary to achieve a high success rate in our experience.

Rainbowfish fry grows slowly, so you should expect to wait several months before the fry is large enough to be added to the adult colony.

Other Rainbowfish of interest

Banded Rainbowfish(Melanotaenia trifasciata)
Boesemans Rainbowfish(Melanotaenia Boesemani)
Celebes Rainbowfish(Marosatherina ladigesi)
Dwarf Neon Rainbowfish(Melanotaenia praecox)
Forktail Blue Eye Rainbowfish(Pseudomugil furcatus)
Honey Blue Eye Rainbowfish(Pseudomugil Mellis)
View all Rainbowfish
Date Added: 02/11/2020 - Updated: 12/08/2022 12:45:58