There also exists a sister-group relationship between the Melanotaeniidae and Malagasy family Bedotiidae, which may seem surprising given their respective modern-day distributional patterns. The precise origin and subsequent dispersal of the two families has been the subject of debate, with some palentologists suggesting that Madagascar’s freshwater fishes derived froma trans-oceanic dispersal during the Cenozoic Era, but the most compelling arguments currently indicate a freshwater radiation which occurred during the Mezozoic break-up of Gondwana.

Generally found within 15-20 km of the sea but habitat-type is extremely variable. It’s been recorded in full marine conditions as well as pure freshwater environments, and commonly inhabits coastal mangrove creeks, swamps, and salt marshes.

Freshwater habitats tend to comprise lowland swamps or forest streams with clear water but some populations inhabit acidic, tannin-stained, black waters. It’s also abundant in the artificial canals typical of residential zones in the Gold Coast, southern Queensland.

Described from ‘Rivulet in sago forest at Ngaiguli, Terangan, Aru Island, Aru Islands, Maluku, Indonesia’, corresponding to the island now normally referred to as ‘Trangan’ in the Aru Islands group, eastern Indonesia.

The islands are located in the Arafura Sea, with western New Guinea to the north and the Arnhem Land Region of Australia’s Northern Territory to the south, and though they lie within Maluku province of eastern Indonesia, are part of the Australian continent in a geological sense.