Melanotaenia goldiei

Melanotaenia goldiei - photo© Neil Armstrong

(Macleay, 1883)
Goldie River Rainbowfish

Species Summary
Melanotaenia goldiei have a distinctive coppery coloured sheen on the upper half of the body with a creamy white colour on the lower half. The mid-lateral stripe is discontinuous, dark blue or blackish, and about 2 scale rows wide. There is a narrow copper or orange-coloured stripe between each scale row on the upper half of the body. Males may reach a maximum size of 10 cm, but females are usually less than 8 cm.

Fly River habitat - photo© Graham Weston

Distribution & Habitat
Melanotaenia goldiei were initially collected from the Goldie River, a major tributary of the Laloki River in southern New Guinea, near Port Moresby in the 1880's. The Laloki River and its major tributaries, the Brown and Goldie Rivers, arise in the lush foothills of the Owen Stanley Ranges in the Central District of Papua New Guinea. Melanotaenia goldiei is one of the most widely distributed rainbowfishes in southern New Guinea, ranging from Lake Yamur (West Papua) eastward to the Port Moresby region. They are very abundant and one of the most common rainbowfish throughout the region. They have also been found on the Aru Islands. Other river systems where Melanotaenia goldiei has been collected include the Fly, Kemp Welsh, Lakekamu, Lorentz, Ok Tedi, Oriomo and Sapoi Rivers as well as the Timika region in West Papua.

Melanotaenia goldiei are found in a wide ranges of habitats, including swamps, backwaters, small creeks, and large rivers. They are most abundant in deep pools behind fallen logs or buttress roots of large trees, where they form loose midwater aggregation. They occur most frequently around sub-surface vegetation, submerged logs, or branches in small tributary streams. Typical habitat consists of small, clear; slow-flowing creeks in closed canopy forest over relatively flat terrain. These creeks typically have mud or gravel bottoms and littered with leaves and log debris. Their natural environment is subjected to seasonal variations with water temperature, pH, and hardness levels varying considerably, and they adapt to the particular water conditions and the seasonal changes when they occur. They have been found in company with Melanotaenia ogilbyi, Melanotaenia papuae, Melanotaenia splendida rubrostriata and Melanotaenia sylvatica. Temperature and pH recorded 24.6~33.0°C; pH 7.0~7.8.

Melanotaenia goldiei [Tapini] - photo© Christophe Mailliet

Remarks
Melanotaenia goldiei was one of the first New Guinea rainbowfishes to enter the aquarium hobby. They were being maintained in the Australian hobby as early as 1958 and perhaps even earlier. Just how many separate collections have occurred over the years is not known, but I know of at least 3 during the early 1970's. What eventually happened to the fish from these importations has been lost in the pages of aquarium history. One collection that has been documented was made by Gerald Allen in 1978. However, as the number of new species arrived from New Guinea, Melanotaenia goldiei fell out of favour with hobbyists and most of the captive stock disappeared. Another collection was made by Heiko Bleher around the late 1980s, and these were introduced to the European hobby. They are known as the "Tapini" variety. These were collected from the Loloipa River, which is an upper tributary of the Angabanga River which flows to the sea near Bereina, Papua New Guinea. Despite this rather long association with the aquarium hobby, not a great deal of information about them has been published in the aquarium literature.

Literature
Allen, G.R. (1991) Field guide to the freshwater fishes of New Guinea. Christensen Research Institute, Madang, Papua New Guinea.

Kailola, P.J. (1987). The fishes of Papua New Guinea. A revised and annotated checklist. Vol. 1. Myxinidae to Synbranchidae. Research Bulletin No. 41. Department of Fisheries and Marine Resources, Port Moresby, Papua New Guinea.

Macleay, W. (1883) Contribution to a knowledge of the fishes of New Guinea, No. 4. Proceedings of the Linnean Society of New South Wales 8 (2): 252-280.

Nichols, J. T. and Raven, H. C. (1934). Two new fresh-water fishes (Percesoces) from New Guinea. American Museum Novitates, No. 755: 1-4.