The rainbowfish is like any other fish belonging to subphylum vertebrates, breathe oxygen through their gills, and have fins for swimming. Although its natural habitat is freshwater sources, however, it is ubiquitously found in aquariums in pet shops and homes because of its beauty.

Rainbowfish is a type of small fish that lives in freshwater and colorful, beautiful, eye-catching, and fascinating. They are attractive because of their multiple color hues in different light settings. Their small size, high energy, and easy to take care of nature makes them the first choice for aquarists to add to their collection.

Everything About Rainbowfish

They have all the characteristics of other fish, but some attributes are specific to them. This easy to care, maintain and breed fish adjust easily with other species in the tank. 

Rainbowfish Profile

Categories Specifications
Scientific name Melanotaeniid
Common name Rainbowfish
Care level Easy
Suitable for aquarium Yes
Tank size Small is suitable
Shoaling/schooling Yes
Diet Omnivore, micro-predator
Reproduction Sexual
Lifespan 5 years average
Origin   Australia, Papua New Guinea 
Temperament Friendly, peaceful
Behavior Active
Size 4-6 inches
Breeding Egg scatters
Biotope Australian, New Guinea

The physical appearance of Rainbowfish

Rainbowfish is a small pet of a few inches in size with the shape of a regular fish. Its distinguishing feature is the presence of multiple vibrant color shades in its skin.

Their color shades may vary like red, silver, yellow, pink, blue, and black when lights of different colors hit their skin.

It contains numerous scales on its body with two adjacent dorsal fins, one pectoral, one pelvic fin, and one caudal fin. Its agility comes from its slender shape, small size, and fins. Another remarkable feature in comparison to other fish is the missing lateral line in its body.

Natural Habitat of rainbowfish

The natural habitat of colorful fish consists of freshwater sources of warm and tropical regions such as Madagascar, Australia, and New Guinea. They live in freshwater channels like rivers, lakes, and streams.

The high growth of plants in these water springs offers them places to hide from other large fish and aquatic creatures and space to lay their eggs. Some of its species also like brackish waters. Some even live in marine environments.

There are multiple threats to the natural habitat of some species of rainbowfish. The numerous population of these species declines in their native ranges due to overharvesting, diseases, other introduced species, pollution, and hybridization with other species.

The Boeseman and Sentani rainbowfish are examples of endangered species due to over-harvesting by human beings due to their increasing demand to keep them in aquariums.

Types of Rainbowfish

There are approximately 50-70 different species of rainbowfish based on various online resources. They mainly divide into two groups. The first one consists of two subfamilies Bedotiidae and Melanotaeniidae, and further divides into three genera Glossolepis, Melanotaenia, and Bedotia.

It contains mostly larger and active fish like Madagascar Rainbowfish. One exception to this group is the tiny filament or threadfin rainbowfish of size 1.2-1.4 inches.

The second group contains the subfamilies Telmatherinidae and Pseudomugilidae. Pseudomugilidae includes smaller and easy to tame fish famous with popular name Blue eyes. 

There are varieties of this freshwater swimmer fish available in the market to be kept in aquariums at homes. 

Some of the popular species commercially available are BosemaniRainbowfish, Neon Dwarf Rainbowfish, Threadfin Rainbowfish, Celebes Rainbowfish, Australian Rainbowfish, and Turquoise Rainbowfish.  

The size of these fish ranges from 2 inches to 8 inches depends upon their species and age. Male and female contain different sizes. Males are usually larger with more bright colors, while females are of smaller size. 

Types of rainbowfish Size (Inches) Habitat
Axelrod’s Rainbowfish 4 Papa New Guinea
Boeseman’sRainbowfish 4 Western Papa New Guinea
Lake KutubuRainbowfish 5 Lake Kutubu
Lake WanamRainbowfish 3 Lake Wanam
Madagascar Rainbowfish 6 Madagascar
Neon Dwarf Rainbowfish 2.5-3 Papa New Guinea
Red Rainbowfish 6 Papa New Guinea

Life span

Rainbowfish belong to the group of freshwater fish having a five-year average life expectancy, slightly shorter than their other counterparts such as neon tetras, angelfish, Oscars.

Their life span can improve through the quality of an environment and mimicking their natural habitat conditions and temperature. The longest-live one of these species is Boeseman’s rainbowfish having a life probability of 5-8 years.

Some fish like to live alone on their own, while rainbowfish prefer to live in a group of five or more. This breed of fish lives as shoals as they remain happy in the group of more than five of their species. 

Diet of Rainbowfish

Rainbowfish belong to the omnivores group of vertebrates and can eat all kinds of food and ranges from vegetation to meat-based food like blackworms and glass worms.

In their natural habitat, they like live plants and live food like algae, insects, blood worms, and other aquatic organisms like Mysis shrimps, small crabs, Daphnia, tadpoles. 

They are the best-known predators for mosquitoes and their larvae. Therefore in some areas are used to control the mosquito population. Different species have different eating habits, but most of them are surface eaters.

For pet rainbowfish, some kind of flakes-foods and frozen foods in the right proportions are mandatory to keep them happy, which increase their size and enhance their colors.

The right dosage and mix of food are also useful to bring your fish in breeding condition. Try to rotate different types of food items every day.  

Feed them what they can eat in one to two minutes once or twice a day as after this food settles down on the floor of the tank, becomes wasted, and pollutes the water. Therefore it is necessary to clean the tank regularly to avoid the deposition of decaying food.

The fry requires tiny foods like Infusoria, rotifers, or some commercially available powdered foods like powdered egg yolk.

Breeding Habits of Rainbowfish

 Rainbowfish has a famous name, Egg scatterer, because they lay eggs and do not care for their child fish. There is a slight difference in breeding habits amongst different species, and they have a similar pattern of breading cycle.

They are also considered an aggressive breeder. We will discuss the general breeding cycle of rainbowfish.

Rainbowfish eggs

They lay eggs in an aquarium if the clean water and food requirements of females fulfill. Females lay eggs in the thick plantation in their natural environment for several days. This process repeats every morning with the sunrise.

Sunlight and temperature rise of the water in the aquarium acts as triggers for this spawning activity. Each female lays around twenty eggs daily for several days. However, the total number of eggs in the complete spawning cycle varies depends upon the type of rainbow fish and its size. 

You should shift the females to an aquarium with heavy plantations during spawning activity because they can eat their eggs and fry.

Hatching of Eggs

Hatching of eggs starts in the sequence as fish lay eggs. Therefore it requires utmost care for fish owners to take care of newly borne larvae, then fry and eggs at the same time because of their coexistence.

Use special mops are available in the market to allow rainbowfish to spawn and collect them daily in a separate water tank with favorable environmental conditions. In this way, you can rear the fry separately in batches. The usual hatching period is 7 to 21 days depending upon the temperature and species.

Raising the Rainbowfish Fry

Hatchlings are challenging and technical to breed due to their small size and special dietary needs. Their fry grows very slowly and requires special care. Feed them infusoria, a combination of tiny aquatic creatures like paramecium cultivated commercially or from your own culture.

It specially designs for newly born fish because of its minute size and nutritional value. Another delicious food item for fry is shrimp larvae. They can also be grown at home. 

Make your life easy by maintaining the supply of these foods at your home by growing your own cultures and coincide with them with the hatching of the fish eggs. You can give vinegar eels to fry as a live food item to imitate their natural habitat.

Feeding the Fry

First, make your aquarium extremely clean before feeding the fry. Feed above mentioned food items four to six times a day in regular intervals in small amounts. Always remember to clean your tank from remaining food items before they decay to ensure a safe environment for your young rainbows.

Keep on feeding these fry in this way until they are grown in size and can eat larger food items.

Tips for Breeding of Rainbowfish

  • Keep females of the same species in a water tank instead of mixing them with other species. Mixing them can cause them to interbred and produce some strange types with less market value.
  • Maintain a natural environment in the tank with plenty of plantations and rocks or use mops to lay their eggs. 
  • Keep eggs and fry away from adult fish as they like to eat them.
  • Maintain your supply of food for fry by growing paramecium or vinegar eel culture at home.

Rainbowfish Color Reflects Its Behavior Changes

Rainbows are peaceful and social fish that enjoys socialization with other types but in a friendly manner. Their males are more aggressive and angry ones as compared to females. Under different mood conditions, they change their colors.

They become red with anger and green of desire. Their color brightens when they feel sick, uncomfortable, or face competition from other males. Male brighten their color to attract females towards them.

Try to keep a single male in one tank to avoid competition and any aggression. Keep the number of females larger than males to maintain a peaceful and happy environment in the aquarium.

Rainbowfish can feel uncomfortable due to loneliness, limited space due to overcrowding, and poor living conditions like water, light, temperature, etc. 

Maintain hiding spots in the water tank by using rocks and plantations (real and artificial) as they tend to hide in an aggressive and stressful environment.

Rainbowfish is a popular pet amongst aquarists because of its beautiful colors, but it has not been born this way. Their newly born have silvery-white color, which becomes more and more colorful and vibrant with age.

Adult fish has different colors depending upon their species. Males grow more colorful than females as they use their colors to attract females for breeding purposes.

What other fish can live with Rainbowfish?

Rainbowfish is a peaceful and socialized pet. They can become socialize with other small and non-aggressive fish of specific species. Name of some of the species which can coexist with rainbowfish includes:

  • Non-aggressive cichlids (such as Kribensis)
  • Zebra Danios
  • Catfish
  • Barbs
  • Large tetras
  • Rasboras
  • Guppies
  • Goldfish
  • Caridina shrimp
  • Neocaridina
  • Angelfish
  • Gouramis
  • Loaches
  • Mollies
  • Platies
  • Plecos

Avoid placing more aggressive and bigger tank buddies with them, as they can harass them and compete with them for food. Examples of such species that should avoid placing with rainbows are:

  • Most types of cichlids
  • Bettas
  • Hatchetfish
  • killifish

Water Requirements for Rainbowfish

Rainbowfish is a freshwater animal of warm tropical regions and require similar environmental conditions in your aquarium.

The chart given below presents some of the typical water requirements of your colorful finned rainbowfish.

Requirements Melanotaeniids Madagascar Rainbows Pseudomugilids
Temperature 74 to 78oF 74-80oF 76-82oF
PH 7-8 6.5-7.5 6.5-7.5
Alkalinity 5°-20° dKH (90-360 ppm). 3°-14° dKH (55-250 ppm). 5°-10° dKH (90-1800 ppm).

Other species require different environmental conditions. Use an aquarium heater if the water temperature falls below 74oF. Clean the water using any filter and process it through the water treatment system before filling the water tank.

Most species can bear a wide range of water conditions from as low as 12oC (54oF) to as high as 30oC (86oF). However, it is good practice to research and inquire about the water requirements of the particular type you buy for your aquarium.

Professional tips for Better Environment for Rainbowfish

  • Perform cleaning of the tank, its plantation, floor, and rocks regularly.
  • It is a good practice to replace one-third of the tank water once a week.
  • Always use dechlorinated water with a temperature matching the room or tank temperature to avoid abrupt temperature changes.
  • Use a siphon to remove debris on the floor of the tank.
  • Make the parasite treatment of your tank a habit regularly.
  • Fish have a weak immune system; therefore, keep the water quality maximum to keep them healthy.
  • Water is free from ammonia and nitrites as they may cause disease in fish.
  • Use a canister filter to keep the water moving and clean.

Aquarium Size Requirements

Rainbowfish are active swimmers and need plenty of free space for swimming. However, their small sizes facilitate the aquarists for lesser space requirements as compared to their larger counterparts.

Different species require different capacity spaces according to their size and swimming habits. Always remember to use a reservoir cover as these fish can jump out of the aquarium. 

Smaller species of Melanotaeniids family, for example, Neon Dwarf, require an aquarium of 30 gallons capacity, While other larger Melanotaeniids require a water tank of about 50 gallons or larger capacity to remain happy. Some other species like Threadfin rainbows can survive in water tanks of size 10-20 gallons. 

 It is a requirement to keep plants and rocks in the aquarium. However, arrange a space for open areas to fulfill the swimming requirements of this active species.

It helps to keep it happy and prevent stressful circumstances due to overcrowding. A well-planted 36-inch aquarium is adequate to meet both of the requirements. 

Related Articles:

Can fish eat seaweed?

Yellow peacock cichlid

Electric Blue Acara Care Guide