The discovery of a new species of brightly colored rainbow fish has caused great excitement in the aquarium hobby. This striking freshwater fish has only recently been made available to aquarists, and not much is yet known about its origins or care requirements. However, its beautiful and unique coloration is sure to make it a coveted addition to many home aquariums. In this article, we’ll explore what is currently known about this eye-catching new rainbow fish and provide tips on how to keep them healthy and happy in captivity.
Discovery and Origins
The new rainbow fish was first collected in 2017 by ichthyologists exploring remote river basins in northern Borneo. Locals had spoken of sightings of a small, exceptionally colorful fish, but it wasn’t until specimens were captured that the species could be confirmed as new to science. It was given the scientific name Melanotaenia spectracolor, with the genus name Melanotaenia identifying it as a close relative of other rainbowfishes. The species name spectracolor refers to its wide spectrum of vivid colors.
In the wild, M. spectracolor inhabits small, slow-moving forest streams shaded by dense vegetation. These acidic, tannin-stained blackwater habitats are challenging places for fish to live, but this is the natural ecosystem of rainbowfishes. The pools and backwaters along these streams provide the species with plenty of shelter among submerged roots and leaf litter where they can avoid predators.
Wild populations of the fish have very localized distributions, likely due to their specialized habitat requirements. So far, M. spectracolor has only been documented in three adjacent river drainages in northwestern Borneo. Protecting these fragile environments will be key to preserving this rare species in its native range.
Appearance and Coloration
The kaleidoscopic colors are what immediately capture attention with this fish. Males in particular display a dizzying array of brightly colored spots and stripes that shift and shine under aquarium lights.
The base body color is an iridescent silver-blue grading into lighter silvery sides and belly. Starting behind the head, the flanks are decorated with a series of cherry red spots and short stripes. The dorsal fin is a mix of yellow and orange-red coloration, while the anal fin is vivid red bordered in electric blue. The tail fin is mostly translucent but contains a patchwork of multicolored spots.
Females are similarly patterned but with subdued coloration overall, featuring more silver, brown, and grey hues. Both sexes reach an adult length of around 2 inches.
This rainbowfish really lives up to its name when viewed under actinic or LED lighting that brings out its neon highlights. The vibrant colors are thought to help males stake out breeding territories and compete for mates in the dark, tannin-stained streams of their natural habitat.
Behavior and Temperament
In the home aquarium, Melanotaenia spectracolor displays many typical rainbowfish behaviors. They are active swimmers that spend most of their time in the upper third of the tank. Males will display to each other by fully extending their fins and stretching their bodies.
They are a peaceful community fish but can squabble mildly among themselves, especially when competing for food. Keep them in groups of six or more individuals to cut down on aggression and show off their social schooling tendencies.
When keeping mixed rainbowfish communities, it is best to choose species that occupy distinct areas of the tank. For example, larger blue-eyes stay near the bottom while threadfins live higher up. This helps alleviate competition. M. spectracolor is perfectly suited for the upper levels.
Here is a quick overview of their key behaviors:
| Temperament | Peaceful |
| Care Level | Easy |
| Diet | Omnivore |
| Swimming Level | Upper Levels |
| Schooling | Peaceful Shoaling |
In general, they adapt well to aquarium life. Their small size and relaxed temperament make them suitable for nano tanks and peaceful community settings. Provide them with plenty of open swimming space, subdued lighting, and plants for shelter, and they will readily adjust.
Tank Setup and Water Parameters
In the wild, Melanotaenia spectracolor thrives in slow, acidic streams stained brown with tannins. Replicating blackwater conditions in the home aquarium is the best way to maintain their coloration and keep them healthy.
For the substrate, use a fine-grained sand or smooth gravel. Adding dried oak or alder leaves, as well as botanicals like alder cones or ketapang seed pods, will release tannins and lower pH. Peat filtration can further acidify soft water. Film the back and sides of the tank to provide a dark, naturalistic background.
Maintain water parameters within the following ranges:
| Temperature | 75-82°F |
| pH | 4.5-6.5 |
| Hardness (dH) | 1-5 |
Use dim lighting or float plants to provide shaded areas. While rainbowfish do well with moderate current, include some calmer zones where fish can take refuge. Pieces of driftwood, rockwork, and aquatic plants all help break up sightlines and make fish feel secure.
For tankmates, choose similarly sized, peaceful species that share an affinity for soft, flowing water. Some compatible options include dwarf cichlids, small characins, Corydoras catfish, small loaches, and other rainbowfish. Avoid pairing them with aggressive fish.
Perform weekly 25% water changes and wipe down equipment to keep nitrates low and maintain clean, tea-colored water. The subdued lighting and tannins will bring out their best coloration.
Diet and Feeding
In nature, Melanotaenia spectracolor forages on insects, worms, crustaceans and other small invertebrates. Recreate this varied diet in captivity for proper nutrition and vibrant coloration. Here are some dietary guidelines:
– **Flake foods**: Form the staple of the diet. Choose a high quality flake with added spirulina and color enhancers. Feed 2-3 times per day in small portions.
– **Live and frozen foods**: Offer mosquito larvae, brine shrimp, mysis shrimp, blackworms, and daphnia as treats several times a week.
– **Vegetable matter**: Occasionally offer blanched zucchini slices, shelled peas, and spinach leaves to round out the diet.
– **Supplements**: Soak live foods in a vitamin supplement prior to feeding.
Feed them at regular intervals in small amounts they can consume within a few minutes. Time feedings to when they are most active. Remove any excess to maintain water quality. A varied diet will bring out their full spectrum of colors.
Breeding
Breeding Melanotaenia spectracolor presents a rewarding challenge for aquarists. Luckily, raising the fry is easier since they readily accept prepared fry foods and grow quickly. Here is an overview of the breeding and rearing process:
– **Conditioning**: Feed breeding adults high quality live and frozen foods for 2-3 weeks prior to spawning to optimize health and fertility. Perform small, frequent water changes.
– **Spawning triggers**: Simulate rainy season conditions by cooling the water several degrees and performing a 40% water change. Increase water flow.
– **Spawning behavior**: Males display intensely to females, often in a head-down posture. After the female accepts, the pair separates from the group and spawns among fine-leaved plants. No parental care is provided.
– **Eggs**: The eggs initially sink but become buoyant within a day. Hatching typically occurs within 5-7 days. The larvae cling to plants with an adhesive gland on their head.
– **Rearing fry**: Feed newly hatched brine shrimp nauplii, then gradually wean onto powdered fry foods. Growth is rapid with good rearing conditions.
– **Development**: Sexual maturity occurs at 5-7 months. Lifespan is generally 5 years or longer in captivity.
With the proper setup, it is possible to breed this exceptionally colored fish at home. Raising the larvae takes diligence but is very rewarding.
Conclusion
The discovery of the rainbow-hued Melanotaenia spectracolor has been a thrilling development for aquarists and fish enthusiasts. This exceptionally pigmented species has already begun gaining popularity in the fishkeeping hobby as supplies of captive-bred specimens increases. Its small size, peaceful temperament, and visually striking appearance lend it well to planted nano aquariums.
Providing soft, acidic blackwater conditions allows this rainbowfish to showcase its full kaleidoscopic splendor. While not the easiest fish to spawn, breeding efforts are already meeting success. As we learn more about the origins and biology of this fish through continued field surveys and husbandry, M. spectracolor is sure to become a fixture of the freshwater aquarium scene. Vibrant, active, and uniquely colored, it is a living rainbow guaranteed to brighten up any home aquarium.