North Queensland Naturalist 46 (2016): 90-98
Keith C. Martin and Susan Barclay
Rocky Creek is a tributary stream of the upper Barron River, on the Atherton Tablelands, north Queensland. Freshwater spring systems occur in the upper reaches, the largest of which is Barney Springs. A rainbowfish variety collected from the spring systems and other sites in the Rocky Creek catchment appeared to be distinctively and unusually coloured compared to other Melanotaenia splendida splendida and Melanotaenia eachamensis samples that were collected from nearby streams elsewhere in the upper Barron catchment. The Rocky Creek rainbowfish is most likely allied to Melanotaenia s. splendida although the form appears to have some colour and patterning characteristics of Melanotaenia utcheensis, a rainbowfish species from the Johnstone River catchment, to the south of the Barron River.
The distinctive colour form of the Rocky Creek springs rainbowfish may be due to its long isolation in an unusual environment combined with genetic introgression with other forms. Rainbowfish from the main channel of Rocky Creek may be mixed to varying degrees with the more continuous and widespread Melanotaenia s. splendida populations that occur further downstream.