Fish Feature: The Colours of the Rainbowfish Family

In this Fish Feature, we will talk about a species that some of you may recognise in the popular children’s book of the same name, the Rainbowfish! Just like it’s name sake, these fish are characterised by their shiny and iridescent scales, girthy body and peaceful disposition.

In the book, there is just one Rainbow Fish in the whole ocean. In reality, the Rainbowfish is a collection of over 50 species that exist in every corner of the globe! This article will help you discover some of the most popular species, and maybe even decide which to add to your tank.

Before we dive into the species, here are some fast facts about Rainbowfish!

Rainbowfish Fast Facts

1. Colour RainbowFish Are Becoming Rarer Occurences

   As its name suggests, the hues that reflect beautiful and vibrant colours resemble a rainbow. (see Dwarf Rainbow below.) Note that the iridescent colours of this species come on more vibrant when the fishes are older and when they are male competing for the attention of a female. However, after seeing these fish in fish shops around Singapore, or perhaps you may have kept someone at home, you might realise the colours on rainbowfish are getting less vibrant. Why are the colours on my Rainbowfish not showing up? You might ask.

2. Commercially sold Rainbowfish are Dropping in Quality

   One of the obvious reasons is that fish shops usually sell rainbowfish young, however, there are a few more pressing explanations. The first, according to a study done on Boesemani Rainbowfish, found that many farms who captive breed BR for the aquarium trade have reported poorer quality of BR produced over the years due to low quality farming practices. The second is the quality of wild-caught Boesemans’ are declining due the large vibrantly coloured males being caught by aquarium traders, leaving the duller-coloured males behind to populate in the wild. Our own research with Singaporean fish merchants has revealed that quality of BR for both captive and wild-caught species have been declining.

3. Rainbowfish Love Schooling

   They prefer living in schools of fish of 5 or more, and these can be numerous species of rainbowfish. Furthermore, they do well with other species of peaceful fish such as angel fish, tetras, guppies and discus. Do note to limit male rainbowfish to one per tank as they may become aggressive towards one another, especially during breeding season. Avoid injuries as much as possible!

   That being said, Rainbowfish are still as wonderful and eye-catching fish to keep as ever, and here are some of the most beautiful species.

   Melanotaeinia Boesemani

   Boeseman’s Rainbow

   Perhaps the most popular rainbowfish, the Boeseman is known for its striking yellow and blue colouration. These fish are endemic to the Ayamaru lakes in Indonesia, meaning these lakes are the only places that natural populations of Boesemani Rainbowfish can be found.

   Origin	Indonesia, Ayamaru Lakes
   Water Conditions	7.0-8.0ph (Moderately Hard to Very Hard)
   Adult Size	4”
   Tank Size	30 Gallons
   Diet	Omnivore - Algae Flakes, Frozen or Live Foods
   Compatibility	Peaceful, suitable for community tanks. Best kept in group of 6. Good tank mates are Tiger Barbs, Danios, Corydoras.
   Tank	Heavily Planted with Open Space
   Lifespan	5 years
   Aquarist Experience Level	Beginner

   

   Melanotaenia lacustris

   Lake Kutubu Rainbowfish

   Did you know? Lake Kutubu is one of Papua New Guinea’s largest lakes, and was It contains 13 native species of fish that are specific to the location, including the Lake Kutubu Rainbowfish. Other species include the Kutubu Tandan. The lake has one of the highest levels of endemicity (the state of a species being native to a specific habitat in the world) in the entire New-Guinea-Australian region, and was one of the most inaccessible regions in the country with access only by light aircraft or on foot, until recently.

   Origin	Papua New Guinea
   Water Conditions	7.0-9.0ph (Moderately Hard to Very Hard)
   Adult Size	5”
   Tank Size	30 Gallons
   Diet	Omnivore - Algae Flakes, Frozen or Live Foods
   Compatibility	Very Peaceful, suitable for community tanks. Corydoras, barbs, danios and other similar sized rainbowfish are some good tankmate suggestions.
   Tank	Heavily Planted with Open Space For Swimming. Best kept in school of 6-8.
   Lifespan	5 years
   Aquarist Experience Level	Intermediate

   

   Pseudomugil Furcatus

   Forktail Rainbowfish

   While many rainbowfish species eventually become too large to be kept with other non species such as dwarf shrimp, this species is one of the few on the smaller size! What this fish lacks in size, makes up in cuteness. With its bright and large blue eyes and bright yellow edges on all its fins, it has one of the most unique combinations of color available in freshwater fish. The best colors can be seen in adult males in schools of 6 or more, where multiple males and females exist. Hardy and adaptable, you can’t not fall in love with this species!

   Origin	Papua New Guinea
   Water Conditions	6.0-8.0ph (Moderate to Hard)
   Adult Size	2.5”
   Tank Size	10 Gallons
   Diet	Omnivore - Algae Flakes, Frozen or Live Foods
   Compatibility	Peaceful and schooling, suitable for community tanks
   Tank	Heavily Planted with Open Space.
   Lifespan	5 years
   Aquarist Experience Level	Beginner

   

   Iriatherina Werneri

   Threadfin Rainbow

   One of the most unique-looking fish out theorem it’s long and fan/feather like fins have attracted much attention from fish enthusiasts around the world. Although this species is widely-traded and produced, it’s only recommended for experienced fishkeepers due to its needs for delicate care and treatment.

   Origin	Papua New Guinea and Northern Australia
   Water Conditions	6.0-7.5pH (Moderately Hard)
   Adult Size	1.6”
   Tank Size	15 gallons
   Diet	Omnivore - Algae Flakes, Frozen or Live Foods
   Compatibility	Docile and Shy, generally not suited for community tanks as it’s easily outcompeted for food. Long fins of mature males may be nipped. Possible tank mates include danios and small corydoras, and otocinclus. Shoals in groups of 6 or more.
   Tank	Heavily Planted with Open Space
   Lifespan	4 years
   Aquarist Experience Level	Expert

   

   Glossolepis incisus

   Red Rainbowfish

   One of the most popular rainbows in the hobby! However, the coloration of today’s mass bred stock from farms or far from the vibrant colours harboured by wild-caught specimens.

   Origin	Papua New Guinea, Lake Sentani in Indonesia
   Water Conditions	7.0-8.0pH (Moderately Hard to Very Hard)
   Adult Size	6”
   Tank Size	30 Gallons
   Diet	Primarily a Carnivore. Hearty and greedy, will accept most food.
   Compatibility	Peaceful, suitable for community tanks. Best kept in a shoal of 6-8.
   Tank	Heavily Planted with Open Space
   Lifespan	6-8 years
   Aquarist Experience Level	Beginner

   

   Melanotaenia praecox

   Dwarf Neon Rainbowfish

   One of the most popular rainbows in the hobby! However, the coloration of today’s mass bred stock from farms or far from the vibrant colours harboured by wild-caught specimens. Like most rainbowfish, males are larger and exhibit brighter colouration than females, also developing a wider and girthier body as they grow.

   Origin	West Papua New Guinea
   Water Conditions	5.8-6.5pH (Moderately Hard to Very Hard)
   Adult Size	3”
   Tank Size	20 Gallons
   Diet	Unfussy and Omnivorous.
   Compatibility	Peaceful, suitable for community tanks. Best kept in a shoal of 6-8.
   Tank	Heavily Planted with Open Space
   Lifespan	5-8 years
   Aquarist Experience Level	Beginner

Rainbowfish available on Fishyhub:

1. Boeseman’s Rainbowfish
2. Threadfin Rainbowfish
3. Dwarf Neon Rainbow
4. Red Rainbowfish