Celebes Rainbowfish (Marosatherina ladigesi): Ultimate Guide

The Celebes Rainbowfish (Marosatherina ladigesi), also known as sail-fin silverside rainbowfish, is a member of the Melanotaeniidae family. They are the smallest species of the rainbow family. The name’s story stems from the geographical area of origin but also pays respect to the ichthyologist who discovered this specific species, Werner Ladiges.

More interestingly, Marosatherina is the combination of Myros (the name of the village where the celeb rainbowfish was initially discovered) and Atherina, which indicates the genus of fish of the silverside family Atherinidae. Celebes, also known as Sulawesi, is one of Indonesia’s four Greater Sunda Islands.

The IUCN (International Union for Conservation of Nature) has listed the Celebes rainbowfish on the Red List of Threatened Species and deemed it near threatened. Celebes Rainbowfish are, however, numerous in captivity and heavily farmed in South-East Asia.

The Celebes Rainbowfish was first described in 1936; it has different names, such as Celebes Sailfish and Celebes Sailfin. It is a slender fish whose body color can change depending on the lighting of your tank. The majority tends to a brown/ yellow hue, with a neon stripe across its back reflecting the blue and green colors. It has pectoral fins that are transparent/white in color and yellow and other fins.

Because of their striking colors and calm temperament, this particular fish can make a great addition to your aquarium; however, caring for them is not as easy as one may think. Let’s explore how to take care of the beautiful Celebes!

Celebes Rainbowfish (Marosatherina ladigesi)
Celebes Rainbowfish (Marosatherina ladigesi)

Celebes Rainbowfish Care

Celebes Rainbowfish are very sensitive to any changes in the tank and can die of common diseases, even in the hands of more knowledgeable fishkeeping. For example, their elaborate fins also mean that they are more susceptible to certain diseases such as fin rot.

Celebes Rainbowfish can also be very shy in the first few days in a new tank, but once they become accustomed to the new environment, they like to swim around freely. As a general rule, tank sizes should reflect the high activity of this species, and we advise you to get a tank no smaller than 20 gallons (or 90 liters) to keep your Rainbowfish happy.

Some expert aquarists advise having a 50-60-gallon (227-272 liters) tank to keep your fish happy with 6 other specimens. Be careful, though: these fish are known to be very good jumpers, so make sure you have a fitted lid to avoid them jumping out!

The Celebes Rainbowfish come from clean and slow-moving waters; as for any other species, the water in the tank should mimic the water of their native geographical area. The Celebs Rainbowfish are known to thrive in tanks where the pH is between 7-8, and the hardness of water is between 12-18 DGH. The tank temperature must be 22-28 degrees Celsius (72–82 degrees Fahrenheit). In order to achieve these parameters, we recommend that you get an aquarium water test kit to help you monitor the parameters very easily.

Celebes Rainbowfish can survive in salty water (very mild), so you can add a little salt: this will also decrease the chance for them to get a very common infection called Velvet disease (also called gold dust, rust, or coral disease). The Oodinium parasite causes this illness. While adding salt to the aquarium, remember these fishes cannot live with too much salt: thus, it is better to add only a half teaspoon of salt per gallon.

Celebes Rainbowfish are tiny creatures, reaching their adult life the size of 3 inches (7.5 cm). To highlight the beauty of the colors and hues of the Celebes Rainbowfish, we recommend a dark substrate with smooth surfaces (to avoid injuries). As mentioned before, the Celebes Rainbowfish can be quite timid in the first few days, so that they will need many hiding spots- better if these are trees or heavily planted plants.

A few plants that provide cover if the fish should choose to retreat include Water Wisteria, Hornwort, and Java Moss. Be sure to leave enough room in the tank for your fish to swim in unobstructed.

Lastly, empower the colors of these fish; you can include some lighting fixtures. Be careful, as Celebes Rainbowfish prefer dim lighting and are more active at night.

Feeding Celebes Rainbowfish

One very important thing you need to do to ensure your Celebes Rainbowfish are happy is a good and balanced diet. Diet is one of the most important parts of caring for these fish, as they can get quite moody and temperamental when hungry. The Celebes Rainbowfish is omnivorous.

As omnivores, they will easily accept anything you give them, including dried and frozen foods, such as daphnia, tubifex, brine shrimp, or blood worms once a week. You can also give them flakes, pellets, frozen foods, tiny vegetable matters, and some meaty foods.

A fun fact about Celebes rainbowfish is that they have a very small throat, so they must be fed smaller portions of food that can be consumed within five minutes. You should feed them at regular intervals, four to five times daily. Also, since the shy nature of these fish, you need to be careful that more aggressive species don’t overpower them and steal all of their food.

Breeding Celebes Rainbowfish

Celebes Rainbowfish sex is difficult to tell when they are juvenile, but as they get older, males will develop long filament extensions off the fins. The male coloration is also slightly stronger. Like other fish species, the male Celebes Rainbow is larger than its female counterpart and has darker colors. The male second ventral and dorsal fins are also more prominent and spot darker hues than the females.

Breeding Celebes Rainbowfish is not difficult. Celebes Rainbowfish breeding must be done in a separate aquarium with many plants (Milfoil, Cabomba, Riccia, Java moss, and other floating plants) that can make this fish feel comfortable depositing its eggs. Generally, the breeding tank’s pH should be neutral; the water should be slightly salty. The temperature must be dropped slightly (2 degrees) as these fish breed better at lower temperatures.

Morning sunshine often triggers this species into spawning, so having your breeding tank near a window could be useful. The female will become plumper as she fills up with eggs and will scatter these eggs at the bottom of the tank. Once the eggs are laid, you must remove the parents before they eat them. The eggs will usually hatch within 7-14 days, the timescale being very dependent on water temperature. For the first four days after they hatch, they feed on their own yolk sack; but after the initial four days, they start swimming and can be fed with commercial foods, finely ground baby brine shrimp, and infusoria.

Since the Celebes Rainbowfish fry is small and can be eaten by other fish, raising them in a separate tank is important until they are big enough to survive in the community tank. The entire process from the egg stage should take around five months.

Tank Mates

Celebes Rainbowfish are peaceful and best kept with non-aggressive groups of 6 to 8 other species that are slow eaters, swimmers, and non-aggressive by nature. Livebearers, Gobies, Halfbeaks, Mollies, and other rainbowfishes make good companions to the Celebes Rainbowfish. As this fish does not attack nor defend itself, keeping them separate from fin nippers and more aggressive fish species is very important. Examples of incompatible fish are barbs, bettas, cichlids, loaches, and tetras (notorious fin nippers). Caution should always be taken if considering any of these fish for a community tank environment.


On average, Celebes Rainbowfish lifespan is around three to five years. Of course, the lifespan of this fish in your fish tank will depend on how well you nurture it. The Celebes Rainbowfish is a schooling fish and lives in a group of at least five/six fishes as they tend to give off more intense colors.

Water quality is paramount for the Celebes Rainbowfish. To maintain the water’s parameters, your tank must have a good filtration system that can eliminate waste build-up; you should also ensure that 25-50% of the total water is changed weekly. It is also necessary to keep checking the salt content in water and other factors. Due to their high water sensitivity, looking after the water filtration rate and cleanliness is crucial to avoid disease or health problems.

Where to Find Celebes Rainbowfish for Sale

Celebes Rainbowfish are very easy to find in all pet or fish stores. If you cannot find them in any of your local stores, you can buy them online. They can be easily found on any online platform. The average price is about 7.00 USD each.

We hope this guide clearly illustrates how to take care of these beautiful fish so they can enjoy a long and happy life.

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