A rare and highly active rainbowfish native to West Papua, Indonesia (Wapoga River basin). Known as the 'Wapoga Rainbowfish', they undergo a dramatic color transformation as they mature, developing intense metallic blues, greens, and reds. As exceptionally fast, continuous swimmers, they require a 4-foot (120cm) aquarium minimum to thrive without stress.
Allen's Rainbowfish At a Glance
Allen's Rainbowfish Tank Requirements
Will Allen's Rainbowfish fit in your tank?
Care guides tell you what Allen's Rainbowfish needs, the next question is whether your tank can safely provide it. Test Allen's Rainbowfish against your tank size, maintenance needs, and the fish you already keep before you buy.
Useful setup supplies
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Allen's Rainbowfish Water Parameters
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Allen's Rainbowfish Temperament & Compatibility
Allen's Rainbowfish Varieties
Each variety inherits the species defaults above. Only differences are highlighted.
Male
Males possess a deeper body profile and develop spectacular red, orange, and metallic blue coloration as they mature. They are peaceful but will display actively (sparring without injury) at each other and females.
Differs in 2 traits from base species
Also known as: Show Male, Wapoga Red
Female
Females are slightly smaller, more slender, and lack the vivid reds and oranges of the males, remaining mostly silver/olive. Keeping a higher ratio of females to males (e.g., 2:1) is recommended to disperse male breeding harassment.
Differs in 1 trait from base species
Also known as: Silver, Female Rainbowfish
Standard / Juvenile
Typically sold at 3-5cm. Juveniles are plain and silvery. It takes several months of high-quality diet and stable conditions for their true adult colors to manifest. They should be grown out in a school.
Differs in 1 trait from base species
Also known as: Unsexed, Juvenile
Allen's Rainbowfish Care Guide Summary
The Allen's Rainbowfish, scientifically known as Chilatherina alleni, belongs to the Rainbowfish family group. Adults reach a maximum size of approximately 10 cm and have a fusiform body shape with a moderate growth rate. Classified as peaceful, this species primarily occupies the surface and mid-level zones of the aquarium and produces a low level of biological waste.
To thrive, the Allen's Rainbowfish requires a freshwater only aquarium with a minimum volume of 150 litres and a tank length of at least 120 cm. Water temperature should be maintained between 24°C and 29°C, with a pH range of 6–8.4 and a general hardness of 4–15 dGH. A moderate water flow is preferred.
The Allen's Rainbowfish is a rewarding species to keep, provided its core environmental needs are met. This species is available in 3 varieties: Male, Female, and Standard / Juvenile. Each may differ slightly in size, temperament, or care needs, so it is worth checking the specific requirements of the variety you plan to keep.
Allen's Rainbowfish Habitat Setup
When setting up an aquarium for the Allen's Rainbowfish, a moderate water flow best suits their natural preferences. Because this species occupies the surface and mid-level zones, the aquarium layout should prioritise adequate surface area with floating cover to make them feel secure near the waterline and open swimming space in the centre of the tank for free movement. Useful additions include driftwood, which can serve as both a hiding place and a dietary supplement and light plant coverage for partial shade. Keepers should note that a tight-fitting lid is essential, as this species is a known jumper.
Allen's Rainbowfish Compatibility Notes
Classified as peaceful, the Allen's Rainbowfish is a schooling species that feels most secure in a sizeable group, where natural shoaling behaviour reduces stress and brings out their best colours. When choosing tankmates, their energetic swimming style may stress more sedentary or timid species. Selecting tankmates that favour different water layers from the surface and mid-level zones can help reduce competition and territorial overlap.
Allen's Rainbowfish Recommended Tank Sizes
Standard aquarium sizes that meet the minimum volume and length requirements for Allen's Rainbowfish.
55 Gallon Standard
60 Gallon Breeder
75 Gallon Standard
90 Gallon Standard
125 Gallon Standard
150 Gallon High
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Frequently Asked Questions About Allen's Rainbowfish
How big does Allen's Rainbowfish get?
Allen's Rainbowfish (Chilatherina alleni) typically reaches a maximum adult size of approximately 10 cm. They have a fusiform body shape and a moderate growth rate.
What tank size does Allen's Rainbowfish need?
A minimum aquarium volume of 150 litres and a tank length of at least 120 cm are recommended for Allen's Rainbowfish. This ensures enough swimming space and helps maintain stable water conditions.
What water parameters does Allen's Rainbowfish need?
Allen's Rainbowfish thrives in freshwater only conditions with a temperature range of 24–29°C, a pH between 6 and 8.4, and a general hardness of 4–15 dGH. A moderate water flow is preferred.
Is Allen's Rainbowfish peaceful or aggressive?
Allen's Rainbowfish is classified as peaceful with an aggression score of 2 out of 10. They are generally well-suited to peaceful community tanks.
How many Allen's Rainbowfish should be kept together?
Allen's Rainbowfish is a schooling species and should be kept in groups of at least 6. Larger groups help distribute aggression and encourage natural schooling behaviour.
Does Allen's Rainbowfish have any special tank requirements?
Yes. Allen's Rainbowfish benefits from plants - lighly covered and driftwood (digestion/hiding) in the aquarium. These features help replicate their natural habitat and promote overall health and well-being.
Does Allen's Rainbowfish need a lid on the tank?
Yes. Allen's Rainbowfish is a known jumper, and a tight-fitting lid or cover is essential to prevent escape. Even a small gap can be enough for a determined fish to leap out.
Top Tank Mates for Allen's Rainbowfish
These fish are strong compatibility matches for Allen's Rainbowfish based on water preferences, temperament, adult size, and tank behavior.
Dainty Cory (Salt and Pepper Cory)
Corydoras habrosus
Ideal Tank MatesZebra Shovelnose (Tigrinus Catfish)
Brachyplatystoma tigrinum
Ideal Tank MatesIncolicana Corydoras
Corydoras incolicana
Ideal Tank MatesEmerald Green Cory
Corydoras splendens
Ideal Tank MatesDuplicareus Corydoras
Corydoras duplicareus
Ideal Tank MatesLoxozonus Corydoras (C079/C082)
Corydoras loxozonus
Ideal Tank MatesPlants That Suit Allen's Rainbowfish
These plants pair well with Allen's Rainbowfish based on shared water preferences, layout fit, and how likely they are to hold up in the same aquarium.
African Onion Plant
Crinum calamistratum
Afzel's Anubias
Anubias afzelii
Anacharis
Egeria densa
Ashy Pipewort
Eriocaulon cinereum
Baby Tears
Lindernia rotundifolia
Balansae
Cryptocoryne crispatula
Fish Similar to Allen's Rainbowfish
Bulolo Rainbowfish
Chilatherina bulolo
A rare and highly active rainbowfish native to the fast-flowing mountain streams and white-water rapids of the Markham and Ramu river systems in Papua New Guinea. They possess a silvery body with a distinct black streak on the upper and lower edges of the caudal fin. Because of their specialized natural habitat, they require highly oxygenated, fast-flowing water and alkaline conditions to thrive in an aquarium.
Blue Rainbowfish
Melanotaenia caerulea
A small, highly active, and colorful schooling fish native to the Kikori River system in Papua New Guinea. They are peaceful but require ample swimming space and a school of their own kind to thrive. Like most rainbowfish, they appreciate well-oxygenated, flowing water and are excellent jumpers. Males develop a striking blue hue with reddish horizontal stripes.
Axelrod's Rainbowfish
Chilatherina axelrodi
A highly active, colorful schooling fish native to Papua New Guinea. Known for a bluish-grey upper body and yellowish-white lower body divided by a dark lateral stripe. Like most rainbowfish, they are incredibly fast, active swimmers that require pristine water, moderate flow, and significant horizontal swimming space.
Eastern Rainbowfish
Melanotaenia splendida
An active, schooling species native to Australia, highly variable in color depending on the catch location. They are fast swimmers that require long tanks with ample open swimming space. Because of their energetic feeding behavior, they can outcompete shy or slow-moving fish. Best kept in shoals to display natural morning sparring and courtship behaviors.
Exquisite Rainbowfish
Melanotaenia exquisita
A highly active, schooling species native to the fast-flowing, clear streams of Australia's Northern Territory. True to their name, they display stunning metallic bodies with bright red-tipped fins. They require pristine, well-oxygenated water, plenty of horizontal swimming space, and should always be kept in groups of 6 or more.
Celebes Rainbowfish
Marosatherina ladigesi
An active, schooling fish native to the karst (limestone) streams of Sulawesi, Indonesia. Known for their striking neon blue lateral stripes and yellowish fins. They strictly require hard, alkaline water to thrive and are highly sensitive to soft, acidic conditions. A peaceful species that requires plenty of open swimming space.