Lake Kutubu Rainbowfish - Melanotaenia lacustris : Complete Fish Profile & Care Guide
Table of contents
Introduction
The Lake Kutubu Rainbowfish (Melanotaenia lacustris) is a captivating and vibrant freshwater fish species renowned among aquarium enthusiasts. These rainbowfish are celebrated for their striking iridescent colours and captivating behaviours. As is characteristic of numerous Rainbowfish species, juveniles may present a relatively subdued appearance in comparison to their resplendent adult counterparts, thereby potentially evading due recognition in commercial outlets. Nevertheless, when introduced into a carefully cultivated planted aquarium, these youthful individuals will gradually undergo a vibrant transformation, unveiling their innate adult radiance while thriving within the secure confines of their aquatic environment.
These Rainbowfish may be peaceful creatures, but with their size and rapid movements, they can unintentionally unsettle slow-moving or smaller fish in their vicinity. Lake Kutubu Rainbowfish are also known to be quite skittish and thrive when kept in a school of at least 6 to 8 individuals, if not more, encouraging the males to flaunt their brilliant colours in the company of their own kind. Bear in mind that a suitably sized aquarium is a must if you intend to accommodate a sizable group of these lively creatures. But fear not, for there is a wide range of compatible tankmates for the Lake Kutubu Rainbowfish, including other similarly sized Rainbowfish, Barbs, Danios, Catfish such as Corydoras and Gobies, and many species of Rift Lake Cichlids, whose water requirements align with the Lake Kutubu Rainbowfish. These fish are naturally playful and exuberant, but their antics can turn aggressive and violent when paired with incompatible tank mates.
To ensure the optimal well-being of Lake Kutubu Rainbowfish, it is imperative to house them in an aquarium of a minimum length of 4 feet, acknowledging the dynamic and active nature of this species, which necessitates ample swimming space. You should maintain these Rainbowfish in an environment that faithfully replicates their native lake habitat. This entails furnishing a densely planted tank, complete with a dark-hued sandy substrate, select pieces of bogwood, a limited arrangement of smooth river rocks, and an ample expanse for unhindered swimming. Crucially, these fish thrive in water characterized by high hardness and alkalinity, which should be meticulously filtered to ensure optimal water quality. Minimal to negligible water movement is preferred to mirror their natural habitat. When selecting plant species for the aquarium, it is imperative to choose those that are compatible with the specific water parameters.
The Lake Kutubu Rainbowfish sports an elongated body, which deepens as the fish ages, and a narrow triangular head. The fish has big, expressive eyes and a pair of dorsal fins. Typically, these fish exhibit a teal to cobalt blue colour on top, which fades into a green hue, while the bottom is silvery or yellowish. Interestingly, these fish display a thin cobalt blue stripe that starts at the tail and disappears in the middle of the body, adding to their mesmerizing beauty.
Lake Kutubu Rainbowfish Photos
Sexual Dimorphism
It is discernible to differentiate between the male and female Lake Kutubu Rainbowfish through several distinguishing characteristics. Males exhibit a slightly larger physique, an arched back, and a markedly more vibrant colouration than females. Furthermore, as they mature, males develop a broader body and display a more aggressive demeanour than their female counterparts.
Quick Facts
| Scientific Name | Melanotaenia lacustris |
|---|---|
| Year Described | 1964 |
| Other Names | Turquoise Rainbowfish, Blue Rainbowfish |
| Kingdom | Animalia |
| Classification | Actinopterygii |
| Order | Atheriniformes |
| Family | Melanotaeniidae |
| Genus | Melanotaenia |
| Origins | Papua New Guinea |
| Max Size | 12.5 cm |
| Temperament | Peaceful |
| Aquarium Level | Middle |
| Difficulty | Intermediate |
| Shoaling | Yes |
| Best kept as | Groups 6+ |
| Diet & Feeding | Omnivore |
| Reproduction | Egg Depositor |
| Average Lifespan | Up to 8 Years |
Water Parameters
| Water Type | Freshwater |
|---|---|
| pH | 7.0 - 8.5 |
| GH | 8 - 25 |
| ℉ | 70 - 79 |
|---|---|
| ℃ | 21 - 26 |
Natural Habitat
The Lake Kutubu Rainbowfish, a stunning aquatic species, is exclusive to the crystal-clear, serene waters of Lake Kutubu, located in the Kikori River system in the exotic Oceania region. These delightful creatures thrive in an environment replete with submerged logs, roots, and abundant aquatic vegetation, congregating in clusters to feast on algae, insect larvae, and small crustaceans.
Every two years, an unusual phenomenon grips Lake Kutubu as a murky up-flow of water emerges from the lake's depths, resulting in a drastic decrease in oxygen levels, thereby decimating the Rainbowfish population. This catastrophic occurrence has become a matter of grave concern, with the once abundant Lake Kutubu Rainbowfish now classified as endangered. Therefore, it is imperative that we work to protect this beautiful species to preserve its unique beauty and ensure its survival for generations to come.
Breeding
To successfully breed Lake Kutubu Rainbowfish, it is recommended to establish a dedicated breeding tank that contains soft acidic water, a sponge filter, and an ample amount of fine-leaved plants, which can be substituted with a spawning mop if necessary. A group consisting of three males to two females of the species should be introduced to the breeding tank after conditioning them with live and plant-based foods to emulate the abundance of the flood season.
Upon laying eggs, the males will exhibit a remarkable display of vivid colours, leading the female to the spawning site to complete the process. To prevent the parents from consuming the eggs, remove the spawning mop or plants and replace them after the process is completed. The fish will continue to reproduce daily for several days, with a decreasing number of eggs being produced. Therefore, it is advised to remove the parents from the tank either when the egg count falls or when the females exhibit signs of fatigue.
Approximately 7 to 12 days following the spawning process, the eggs will hatch, and the fry will require infusoria or liquid fry food until they are sufficiently large to consume small live foods. The fry's rearing process can be challenging and requires attentive care until they reach approximately two months of age.
Diet & Feeding
The Lake Kutubu Rainbowfish is a versatile creature, easily pleased with most foods offered to them. Nonetheless, it is highly recommended to serve up a nutritious, well-rounded diet consisting of high-quality dried food, like pellets or flakes, as well as frozen and live foods such as bloodworms, brine shrimp, and tubifex to ensure optimal health and vibrancy. Feeding your Rainbowfish regularly, 2 to 3 times a day, with a scrumptious spread of dried and live foods will help your fish showcase their best colours and condition. Remember to provide only what they can consume in 5 minutes or less to prevent overfeeding, which can lead to health issues.
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