20 Colorful Species of Rainbowfish

<p>MarSpb20/Getty Images</p>

MarSpb20/Getty Images

Rainbowfish are a common freshwater community fish, but are you aware how many species are out there? All members of the Melanotaeniidae family, the rainbowfish, are a wonderfully diverse group of fishes that are native to the islands of Australia, New Guinea, Indonesia, Sulawesi and Madagascar. Almost all rainbowfish species are community fish that get along with other non-aggressive freshwater fish species in an aquarium. Keep in mind, fish from different parts of the world will often have different water quality requirements, so not all species need the same water parameters.

There are many species on this list that are endangered or threatened in the wild. When possible, always purchase fish from fish stores that buy from reputable breeders to ensure you are not buying fish taken from their native environments.

Species Characteristics

Rainbowfish are classified by their elongated premaxillary teeth. They live in freshwater, including rivers, lakes, and swamps. They prefer to live in planted areas and reproduce by laying eggs. Most rainbowfish species prefer schooling together in a small group. There are various sizes and body shapes in rainbowfish. Here are some of the most colorful ones available from fish retailers.

In a home aquarium, rainbowfish need well-oxygenated water with a pH level of 6.8 - 7.2, optimal temperatures varying between 72-82 degrees F (22-28 degrees C). Provide plenty of aquatic plants to give them hiding places. If properly cared for, rainbowfish can live for 5 years in aquariums.

Boesemani Rainbowfish

<p>wrangel/Getty Images</p>

wrangel/Getty Images

One of the most recognized rainbowfish in the aquarium hobby, the Boeseman's or Boesemani Rainbowfish has a two-toned color with a blue/purple head and an orange/red back end. These rainbowfish are very easy to care for and are a common fish in many tropical community aquariums. They do well in groups, and the males' color will often get brighter when they are getting ready to spawn.

Scientific Name: Melanotaenia boesemani

Life Span: 5 years

Length: 4 inches (10 cm)

Physical Characteristics: Wide body, blue/purple head with orange/red back end

Axelrod's Rainbowfish

<p>Shirlie L Sharpe</p>

Shirlie L Sharpe

(image from previous publication)

The Axelrod, or Axelrodi rainbowfish, is named after tropical fish expert Herbert Axelrod. This species of rainbowfish has a lighter colored body with a blue-tinged abdomen. The Axelrod rainbowfish prefers slower moving waters, mimicking the gentle streams of their native waters in the Yungkiri Stream of Papua New Guinea.

Scientific Name: Chilatherina axelrodi

Life Span: 5 years

Length: 4 inches (10 cm)

Physical Characteristics: Wide body, light blue in color and horizontal dark bar along their sides

Desert Rainbowfish

<p>exphorizons/Flickr</p>

exphorizons/Flickr

Desert rainbowfish, native to Australia, have silvery-white females and white males with purple or green-tinged fins. Due to their limited range, they have very specific water quality requirements. A stark color variation compared to many more brightly colored rainbowfish species, this one may more easily hide in lighter-colored décor and is easier to see in darker environments.

Scientific Name: Melanotaenia splendida tatei

Life Span: 5 years

Length: 4 inches (10 cm)

Physical Characteristics: Wide body, white to silver body with some green or purple on fins, depending on sex

Madagascan Rainbowfish

<p>Mirko_Rosenau/Getty Images</p>

Mirko_Rosenau/Getty Images

A note to fish keepers interested in the Madagascan rainbowfish is this species preference for low pH water. Their native habitats are characterized by extremely soft freshwater, with low pH and tannin-stained water. These rainbowfish have a silver body with yellow fins, and males are more saturated with color than females. The Madagascan rainbowfish may do well with South American cichlids with similar water quality tolerances, such as discus and angelfish, and they like stronger current in their tanks.

Scientific Name: Bedotia madagascarensis

Life Span: 5 to 11 years

Length: 4-6 inches (10-15 cm)

Physical Characteristics: Thin body, yellow/tank body with black bar along sides and belly with re-tipped fins

Banded Rainbowfish

<p>isoft/Getty Images</p>

isoft/Getty Images

The banded rainbowfish is a popular species of rainbowfish, given their bright coloration and peaceful nature. Native to Northern Australia freshwaters, males will have wider, more colorful bodies and a humped forehead. Both males and females have brightly-colored fins with a darker stripe along their midbody. This species prefers being in small groups in planted tanks. Like some other species, males will become aggressive during breeding.

Scientific Name: Melanotaenia trifasciata

Life Span: 5 to 8 years

Length: 6 inches (15 cm)

Physical Characteristics: Wide body, silver with red/orange/gold stripes and red tail

Threadfin Rainbowfish

<p>NERYX/Getty Images</p>

NERYX/Getty Images

In addition to stark differences in their required pH and temperature, the threadfin rainbowfish has a very unique body and fin shapes. They prefer water that is soft to moderately hard, slightly acidic (pH 6.0–7.0), and with a temperature of 73–84 degrees Fahrenheit (23–29 degrees Celsius). They are significantly smaller than other species of rainbowfish, with thin bodies and long extensions on the dorsal and anal fins on males. In addition to their elongated fins, males have faint vertical stripes with red/orange caudal fins.

Scientific Name: Iriatherina werneri

Life Span: 3 to 5 years

Length: 2 inches (5 cm)

Physical Characteristics: Narrow body, red sides, males have elongated black dorsal/anal fins and red-tipped tail fin

Celebes Rainbowfish

<p>cejoos/Getty Images</p>

cejoos/Getty Images

The Celebes rainbowfish is a smaller, more slender species of rainbowfish. This species likes to be kept in large schools of 8-10 fish, so be sure to plan your aquarium accordingly so that you have enough room for everyone. Celebes rainbowfish have a unique fin shape with two dorsal fins colored yellow/golden and black, and a translucent body.

Scientific Name: Marosatherina ladigesi

Life Span: 3 to 5 years

Length: 3 inches (7 to 8 cm)

Physical Characteristics: Narrow body, translucent main body with accented fins with yellow/black, and blue bar along the lateral line.

Neon Rainbowfish

<p>NERYX/Getty Images</p>

NERYX/Getty Images

The neon rainbowfish is one of the smallest rainbowfish species in the commercial market. Given their smaller size, they like to be in larger groups of 10 or more individuals. They are very picky about their water quality parameters, so be sure to pay special attention to your water tests if you are adding a bunch of fish at once. They are named for their neon blue and green coloration, which can present as a brilliant flash in your aquarium as they all school together.

Scientific Name: Melanotaenia praecox

Life Span: 3 to 4 years

Length: 2.5 inches (6 cm)

Physical Characteristics: Wide, light colored body with flashy green/blue accents, and red on fins.

Lake Kutubu Rainbowfish

<p>wrangel/Getty Images</p>

wrangel/Getty Images

The Lake Kutubu rainbowfish is named for its origin at Lake Kutubu in Papua New Guinea. This species of rainbowfish is known for jewel-tone blue, yellow and/or turquoise appearance. Like most rainbowfish species, the males tend to be more vibrantly colored than females.

Scientific Name: Melanotaenia Iacustris

Life Span: 5 years

Length: 5 inches (12 cm)

Physical Characteristics: Wide, light colored body with flashy green/blue accents

Red Irian Rainbowfish

<p>ArtEvent ET/Getty Images</p>

ArtEvent ET/Getty Images

The red rainbowfish, or red Irian rainbowfish, originates from New Guinea’s Tami River and Lake Sentani. Males can be differentiated from females by their bright red coloration with high rounded back. In contrast, females have silver bodies with tints of yellow and green.

Scientific Name: Glossolepis incisus

Life Span: 5 years

Length: 6 inches (15 cm)

Physical Characteristics: Wide body, males are red/orange with females more lighter in color

Lake Wanam Rainbowfish

<p>90 530 152 33 90 IZMIR TURKEY/Flickr</p>

90 530 152 33 90 IZMIR TURKEY/Flickr

Although the Lake Wanam rainbowfish is named for their origins in Lake Wanam in Papau New Guinea, you are very unlikely to find any remaining in their home waters. The Lake Wanam rainbowfish is listed as critically endangered and not common in the hobby, and only sold through specialized breeders. As with any fish species you are looking to purchase, always consider if your fish is coming from a breeder or collected from wild stock.

Scientific Name: Glossolepis wanamensis

Life Span: 5 years

Length: 3 inches (8 cm)

Physical Characteristics: Wide body, darker color with tan/orange/red stripes along their bodies

Forktail Rainbowfish

<p>Mirko_Rosenau/Getty Images</p>

Mirko_Rosenau/Getty Images

The forktail rainbowfish is a small, slender species of rainbowfish with blue eyes and namesake forked tail. Their colors brighten during breeding season, with the males becoming brilliantly yellow. Given their small size, this species really likes being in large groups with lots of plants to hide in.

Scientific Name: Pseudomugil furcatus

Life Span: 3 years

Length: 2.5 inches (6 cm)

Physical Characteristics: Slender body, blue eyes, clear body with yellow/black accents

Crimson-Spotted Rainbowfish

<p>Barry Meiklejohn/Flickr</p>

Barry Meiklejohn/Flickr

Also known as Duboulay's rainbowfish, the crimson-spotted rainbowfish is so named for its characteristic red spot on both sides of their head. Their red coloration continues as red/orange speckles, which may conjoin to form lines, along their body sides. They are native to Australia and have been released into swamps and rivers to help combat mosquitos by eating the aquatic mosquito larvae.

Scientific Name: Melanotaenia duboulayi

Life Span: 3 years

Length: 4.5 inches (11 cm)

Physical Characteristics: Wide body, grey/black body with red/orange spots

Murray Rainbowfish

<p>Jeff Webb/Flickr</p>

Jeff Webb/Flickr

The Murray River rainbowfish, also known as Murray rainbowfish or Australian rainbowfish, have more subtle colors, often being a soft rainbow of blue, green, yellow or silver. Male Murray River rainbowfish will have a bright orange stripe on their back end when they are getting ready to spawn.

Scientific Name: Melanotaenia fluviatilis

Life Span: 3 years

Length: 4.5 inches (11 cm)

Physical Characteristics: Wide, silvery body with green-tinged scales. Fins may have yellow, red or orange pigmentation

Redfin Dwarf Rainbowfish

<p>Mirko_Rosenau/Getty Images</p>

Mirko_Rosenau/Getty Images

The redfin dwarf rainbowfish has a unique appearance with black stripes and vibrant red/orange tinged fins. Native to Australia, this rainbowfish can tolerate a wide range of water quality parameters and they breed readily in captivity.

Scientific Name: Melanotaenia maccullochi

Life Span: 3 years

Length: 3 inches (7 cm)

Physical Characteristics: Wide, silvery-green body with black horizontal stripes, red/orange fins.

Parkinsoni Rainbowfish

<p>Aquarianer Schweiz/Flickr</p>

Aquarianer Schweiz/Flickr

The Parkinsoni rainbowfish is a mix of silver and vivid yellow colors. Depending on the individual, they may have a lot of yellow pigmentation on their sides, or only in their fins.

Scientific Name: Melanotaenia parkinsoni

Life Span: 5 years

Length: 5.5 inches (14 cm)

Physical Characteristics: Wide body, silvery-green body with black horizontal stripes, red/orange fins.

Spotted Blue-Eyed Rainbowfish

<p>Mirko_Rosenau/Getty Images</p>

Mirko_Rosenau/Getty Images

The spotted blue-eyed rainbowfish, also know as Gertrude's spotted rainbowfish, is a small species of rainbowfish that has a unique fin appearance with black spots and vivid yellow tint. As its name implies, their eyes are ringed with blue, giving them a very vibrant appearance. This species of rainbowfish is very small, so they do best in schooling groups of 6 or more fish.

Scientific Name: Pseudomugil gertrudae

Life Span: 12-18 months

Length: 1.5 inches (4 cm)

Physical Characteristics: Narrow body, spots along dorsal and anal fins with yellow tint on tail fin, dorsal fin and body

Lake Tebera Rainbowfish

<p>Mirko_Rosenau/Getty Images</p>

Mirko_Rosenau/Getty Images

The Lake Tebera rainbowfish originates from Papau New Guinea near Lake Tebera. Like Axelrod's rainbowfish, this fish takes its scientific name from aquarist, Herbert Axelrod. They can have a vibrant yellow body with a black stripe along the middle of their sides. Their fins may be tinted red or yellow.

Scientific Name: Melanotaenia herbertaxelrodi

Life Span: 5 years

Length: 4 inches (12 cm)

Physical Characteristics: Wide body, yellow body with black stripe along side

Sentani Rainbowfish

<p>Street Parrot/Flickr</p>

Street Parrot/Flickr

Although they may not be considered very "colorful" compared to other rainbowfish, the orange/tan coloration of the Sentani rainbowfish is a bright contrast against the greens of a planted aquarium. Their fins have a mix of blue/green/red pigments that catch the light as they dart around their tank. This is a critically endangered species, so be wary from where you purchase this species and ensure they are captive-bred individuals. The Sentani rainbowfish shares its habitat with the red rainbowfish and is commonly mistaken for Chilatherina fasciata.

Scientific Name: Chilatherina sentaniensis

Life Span: 5 years

Length: 4 inches (12 cm)

Physical Characteristics: Wide, tan body with pale stripes and multicolored tail

Eastern Rainbowfish

<p>GlobalP/Getty Images</p>

GlobalP/Getty Images

A close relation to the desert rainbowfish, the Eastern rainbowfish has a more orange and grey coloration with iridescent scales. They are best visualized in brightly lit aquariums with lots of plants. These are a larger rainbowfish species, but still do best in a small group.

Scientific Name: Melanotaenia splendida spendida

Life Span: 5 years

Length: 6 inches (15 cm)

Physical Characteristics: Wide body, orange and grey with iridescent scales

Whenever you are looking to add fish to your aquarium, ensure that your water quality parameters are correct before you mix different species. Trying to hit a "sweet spot" to accommodate a variety of water quality requirements may not end well. It is best to pick a mix of species that have compatible water requirements rather than mixing by appearance.

Most rainbowfishes like to be in a small school, so plan on having at least five to six individuals for the larger species and eight to 10 individuals for the smaller species. Ensure that your aquarium will have enough space for all your fish.

Rainbowfish are generally peaceful, community fish, so they can easily be mixed with other tropical community fish, again, provided their water quality requirements are compatible.

Always thoroughly vet any potential vendor to ensure you are buying captive bred fish and are not taking any endangered fish from the wild. Many rainbowfish species are threatened or endangered and need to be purchased from a reliable vendor that sells commercially farmed fish.