Rainbowfish is a type of freshwater fish popular for its unique and colorful appearance. Today, there are more than 50 types of rainbowfish originating from different regions like Australia, Indonesia, Madagascar, and New Guinea. This fish is typically easy to care for, active, and also friendly.
Overview
| Scientific Name | Boesemani Rainbowfish (Melanotaenia boesemani) Madagascan Rainbowfish (Bedotia geayi) Threadfin Rainbowfish (Iriatherina werneri) Red Rainbowfish (Glossolepis incisus) |
| Common Names | Boesemani Rainbowfish – Boesemani rainbowfish Threadfin Rainbowfish – Featherfin rainbowfish Red Rainbowfish – salmon-red rainbowfish, New Guinea rainbowfish |
| Life Expectancy | Five years |
| Adult Size | 4 – 5 inches (for most species) |
Characteristics
| Habitat | Freshwater |
| Origin | Australia, New Guinea, Indonesia, and Madagascar |
| Care Level | Easy |
| Temperament | Friendly, social, and active |
| Diet | Omnivorous |
| Tank Level | Top-dwellers or medium-dwellers |
| Water pH | 7 to 8 pH |
| Water Temperature | Between 74° F and 78° F |
| Water Hardness | 9 dGH to 20 dGH |
| Lighting | Subdued and dim |
| Tank Mates | Tetras, Rasboras, Danios, Mollies |
Fun Fact Corner
- The body color of rainbowfish enhances with age.
- If you keep several male rainbowfish in a breeding tank, they’ll compete with each other by increasing their body color’s intensity!
- Stress can cause your rainbowfish to lose its color.
Origin
Rainbowfish is mainly native to Australia, New Guinea, Indonesia, and Madagascar.
There is no fixed place, as there are more than 50 varieties of Rainbowfish, each originating from a different region. Accordingly, the water requirements also vary. For instance, red rainbowfish originate from water bodies having high vegetation. On the other hand, Madagascan rainbowfish originate from clear streams.
The table below denotes the places of origin of some popular rainbowfish species.
| Rainbowfish Species | Origin |
| Boesemani Rainbowfish | West Papua, Indonesia |
| Axelrods Rainbowfish | Sandaun Province, Papua New Guinea |
| Desert Rainbowfish | Australia |
| Madagascan Rainbowfish | Madagascar |
| Banded Rainbowfish | North Australia |
| Threadfin Rainbowfish | North Australia, New Guinea |
| Neon Rainbowfish | Mamberamo River Basin, Indonesia |
| Forktail Rainbowfish | Papua New Guinea |
| Redfin Dwarf Rainbowfish | Australia, Papua New Guinea |
Temperament
Rainbowfish is one of the best fish for beginners. This fish species is friendly and social. Therefore, it will interact with most of the other tank mates. It is also extremely active and loves to swim fast against the current!
Note that rainbowfish thrive well in groups. So, it is best to keep a school of five to six rainbowfish together. If kept alone, it might become timid or feel stressed.
Lifespan
The lifespan of rainbowfish varies as per the species. However, the average lifespan for most rainbowfish is five years in the wild. Certain species like Madagascan Rainbowfish can even live up to eleven years!
In captivity, a rainbowfish’s lifespan depends on the level of care you’re providing them. Hence, it can range anywhere between five and eight years.
Size and Appearance
Most rainbowfish species can grow up to 4 to 5 inches in size. Again, the size varies as per the species. Certain species like neon rainbowfish can only grow up to 3 inches, whereas some like Van Heurn’s rainbowfish can even grow up to 7.9 inches.
Body Shape and Color
No two rainbowfish species have the same body shape and color. They are all peculiar and offer unique colors and markings!
The table below gives a general idea about the body shape and color of the most popular rainbowfish species.
| Rainbowfish Species | Body Shape | Body Color |
| Boesemani Rainbowfish | Flat and oval | Bicolored – blue tones near the head and orange tones near the tail. |
| Madagascan Rainbowfish | Streamlined shape | Silver due to the presence of shiny scales. The fins and tail have a bit of yellow, along with black markings. |
| Banded Rainbowfish | Long and deep body with a narrow head | Comes in various body colors like red, green, blue, yellow, or purple. The fins are red. The presence of a black or blue mid-lateral strip is a standout feature. |
| Threadfin Rainbowfish | Long and sleek body | Considered the most attractive rainbowfish due to the presence of long and beautiful fins. The body consists of silver scales with tints of orange and blue. There are faint vertical stripes present on the body too. |
| Neon Rainbowfish | Oval and deep shape | The body has a vivid and shiny blue color. The fins are red in males and yellow in females. |
| Forktail Rainbowfish | Torpedo-shaped body | The body color is silver-gray, along with some greenish-yellow tints present all over. |
| Red Rainbowfish | Oval with rounded backs | Presence of vibrant red and orange scales with tints of golden. |
Differences Between Male and Female Rainbowfish
There are a few obvious differences between male and female rainbowfish. These differences typically differ species-to-species. However, some of the common variations are listed below.
| Category | Male Rainbowfish | Female Rainbowfish |
| Body Color | They have a more vivid and striking body color | Dull colors in comparison |
| Fins | Often longer and more elongated | Often more rounded |
| Other Differences | Presence of a “courtship stripe” during spawning period | No “courtship stripe” present |
Breeding
It is easy to breed most rainbowfish species. However, ensure that you breed two similar rainbowfish species, as cross-breeding may lead to stunted or underdeveloped fry.
Follow the below-mentioned instructions to breed rainbowfish.
- Take a separate breeding tank, and add rainbowfish to it in a male-to-female ratio of 2:3.
- Breeding requires higher temperatures. So, increase the water temperature to 77°F. Add some plants like java moss and spawning mops to the breeding tank.
- Allow the male and female to breed. You’ll notice that the males become more colorful (some might even possess a courtship stripe) while trying to mate with the female.
- The female rainbowfish will become plumper during the spawning period. She’ll lay around 5 to 30 eggs in one go.
- Once the female fish has laid the eggs, remove all adult rainbowfish from the breeding tank. Else, they might eat their own eggs.
You can feed infusoria to the free-swimming fry. Then, provide them with newly-hatched brine shrimp after a week!
Nutrition and Diet
Rainbowfish has an omnivorous diet. In the wild, this fish species feeds on insects, mosquito larvae, zooplankton, and tiny crustaceans.
If you’re planning to keep rainbowfish in your aquarium, it is best to feed them high-quality pellets and flakes. You can also feed them live or frozen food options such as blood worms, daphnia, mosquito larvae, brine shrimp, and black worms.
You should feed rainbowfish three times a day, and ensure that they finish the food within three minutes. If you still notice some leftovers, reduce the amount next time.
Tank Requirements
Most rainbowfish species are either top-dwellers or mid-dwellers. Note that as rainbowfish can be of various types, it is best to mimic the natural environment of the one you’re planning to keep in your aquarium.
Tank Size
The tank size depends on your rainbowfish species. If your rainbowfish is around 3 inches, you can house six of them in a 15-gallon tank.
On the other hand, rainbowfish species above 3 inches should be kept in a 30-gallon tank.
Water Requirements
Most rainbowfish varieties prefer neutral and slightly-hard water. Yet, some varieties can also live in hard and alkaline water conditions.
- Water Temperature – Rainbowfish species belong to tropical or subtropical temperatures. So, try to maintain the water temperature between 74° F and 78° F.
- Water pH – Neutral to alkaline water works best for most Rainbowfish species. Try to keep the water pH between 7 and 8.
- Water Hardness – The water hardness should be kept between 9 dGH and 20 dGH.
- Water Flow – Rainbowfish are quite active, and prefer moderate but gentle currents.
Decoration and Plants
Even though rainbowfish are pretty social and active, they need some hiding spots. So, keep a few rocks and caves in your aquarium. You can also keep a few popular aquatic plants.
Some of the best plants for rainbowfish include:
- Wisteria
- Java moss
- Java fern
- Anubias
- Hornwort
- Crypts
When it comes to the substrate, opt for a dark and sandy substrate. This will bring out your fish’s color, while also mimicking its natural environment!
Lighting
You should try to provide dim and subdued lighting to your rainbowfish. There should also be a few shaded areas in the tank. You can use floating plants to create shaded areas in your fish tank.
Best Tank Mates
Rainbowfish can get along with most other fish species. You can even keep different rainbowfish species together in the same tank. Ensure that the male-to-female ratio is 2:3 to avoid any form of aggression.
Some other tank mates that are suitable to house with rainbowfish include:
- Neon Tetras
- Harlequin Rasboras
- Danios
- Mollies
- Gold Barbs
- Corydoras catfish
- Plecos
- Platies
On the other hand, some fish species to avoid keeping with rainbowfish include:
- Slow-moving fish species
- Bettas
- Cichlids
- Avoid keeping fin-nipping fish species (angelfish, gouramis, serpae tetra) with threadfins rainbowfish
