Oktedi Rainbowfish - Melanotaenia oktediensis
The Oktedi Rainbowfish was scientifically described by Allen & Cross in 1980. Its scientific name is Melanotaenia oktediensis. The species was first discovered by Dr. Tyson Roberts in 1975 when he has doing in an ichthyologic survey of the Fly River system.
The Oktedi Rainbowfish can reach a length of roughly 12 cm (4.7 inches). The back is of a coppery brown shade while the lower half of the body is white or pale lilac. There is a prominent mid-lateral stripe.
Geographical distribution, habitat and conservation
This species lives in southern Papua New Guinea and has only been encountered in the Ok Tedi River and its tributaries in the Upper Fly River system. Oktedi Rainbowfish is present in the main river, but is not as common there as in the small tributaries. These tributaries are located in mountainous terrain at elevations of 300-500 meters (roughly 985-1640 feet). A majority of the collected specimens hails from tributaries located 900-950 km (roughly 0.5 mile) upstream from the sea, near the mining town Tabubil. This part of Papua New Guinea is covered in dense jungle vegetation and receives one of the highest rainfalls on the planet. The typical Oktedi Rainbowfish habitat has clear water and a rocky bottom. The water temperature is 17-24 degrees C (63-75 degrees F) and the water is alkaline, from pH 7.3 to 8.7.
The Oktedi Rainbowfish is listed as “Vulnerable” in the IUCN Red List of Threatened Species. The species is threatened by water pollution from the Ok Tedi copper mine.
Keeping Oktedi Rainbowfish in aquariums
Oktedi Rainbowfish is not tricky to keep and is a popular aquarium fish even outside Australia. Try to resemble its natural habitat when you set up the aquarium and use rocks to created sheltered spots.
The Oktedi Rainbowfish is used to comparatively cool mountain conditions from the wild and the recommended water temperature in the aquarium is 22-26 degrees C (72-79 degrees F). The water should be alkaline with a pH-value of 7.3-8.7. Powerful aeration is recommended since that will resemble the conditions in a swift-flowing mountain streams.
The wild Oktedi Rainbowfish feeds chiefly on algae and ants and must therefore be give both plant based and meaty foods in the aquarium. Natural algae growth is beneficial but should always be supplemented with algae- or vegetable based foods. You don’t have set up an ant farm in your kitchen; protein rich live food such as brine shrimp and insect larvae will work just as well. A diet consisting of dead food only can cause the fish to dampen its colours.
Breeding Oktedi Rainbowfish
Breeding Oktedi Rainbowfish in the aquarium is not very difficult. Provide your fish with suitable spawning media, e.g. java moss or spawning mops. Just like many other rainbowfishes, the Oktedi Rainbowfish will normally release its eggs in the early morning hours. If you keep the water temperature in the upper part of the recommended range, the eggs will normally hatch within two weeks. You can feed the fry infusoria and finely powdered flakes until they are large enough to devour newly hatched brine shrimp and gnaw on whole flakes.
Other New Guinea Rainbowfishes
Tami River Rainbowfish
Lake Wanam Rainbowfish
Goldie River Rainbowfish
Lake Tebera Rainbowfish
Irian Jaya Rainbowfish
Lake Kutubu Rainbowfish
Lake Kurumoi Rainbowfish
Pima River Rainbowfish
Dwarf Neon Rainbowfish
Fly River Rainbowfish
Red Striped Rainbowfish
Van Heurn’s Rainbowfish
Central American Cichlids
Frogs and Turtles
Lake Victoria Cichlids
Marine Aquarium Fish
Responsible Fish Keeping
South American Cichlids
Tropical Fish Food