Volume 21, Issue 2 – 15 April 2015
Volume 21, Issue 2 – 15 April 2015
New Scientific pubblication – started delivery on April 15, 2015
Keith C. Martin and Susan Barclay: Distribution and status of Banded Rainbowfish Melanotaenia trifasciata (Melanotaeniidae) populations in north-eastern Queensland, pp. 54-65
The Banded Rainbowfish Melanotaenia trifasciata has a wide but patchy distribution across northern Australia. It reaches its southern range limit in north-eastern Queensland, where it has been historically recorded from a number of locations from the Normanby River in the north, to the Hull River in the south. In this study, all recorded localities of the species in the region were re-surveyed to determine the current extent and status of populations in the region. Melanotaenia trifasciata populations were confirmed at 15 sites within four drainage systems including two small streams draining the Mount Stuckey massif, the McIvor-Morgan Rivers system, streams of the Wyalla Plain and Cooper Creek in the Cape Tribulation area. The population in the McIvor-Morgan system appears to be extensive, but populations in the other three drainage areas, especially Cooper Creek are extremely limited and likely vulnerable to environmental change. Records from sites where M. trifasciata had been previously recorded, but could not be confirmed are most likely attributable to either misidentifications of similar species (particularly M. splendida and M. utcheensis), failed translocations or historical extinctions. There is some evidence that the species previously had a wider distribution in the region. Melanotaenia trifasciata populations in north-eastern Queensland are particularly fragmented and habitat specific. All populations occur in coastal lowland situations and prefer clear, heavily shaded, perennially flowing streams. None of the populations occur within currently protected areas.
Melanotaenia trifasciata (adult males) from north-eastern Queensland: a) stream near Mount Stuckey; b) McIvor River; c) Wyalla Plain (Russell Creek); and d) Cooper Creek. Photos by K. C. Martin.
Gerald R. Allen, Renny K. Hadiaty, Peter J. Unmack and Mark V. Erdmann: Rainbowfishes (Melanotaenia: Melanotaeniidae) of the Aru Islands, Indonesia with descriptions of five new species and redescription of M. patoti Weber and M. senckenbergianus Weber, pp. 66-108
The Aru Archipelago is a relict of the former land bridge connecting Australia and New Guinea and its freshwater Melanotaenia strongly reflect this past connection. Sea level changes over the past 2-3 million years have apparently provided sufficient isolation for the radiation of a minispecies flock consisting of at least seven species. Melanotaenia patoti and M. senckenbergianus were described from the islands by Weber in the early 1900s, but subsequently considered as junior synonyms of the New Guinea mainland species M. rubrostriata and M. goldiei respectively. Recent collections by the authors facilitated a reassessment of their status based on morphological and genetic investigations, consequently both are here recognised as valid and redescriptions are provided. In addition, the current study reveals the existence of five new taxa described herein. M. albimarginata n. sp. is described from 36 specimens,
35.3-90.9 mm SL, collected at Kobroor Island. It is allied to the “Australis” group of species of Australia and southern New Guinea. It differs from its closest Aru relatives, M. patoti and M. aruensis, on the basis of colour pattern, caudal peduncle depth, lateral scale counts and average number of cheek scales. Melanotaenia aruensis n. sp. is described from 19 specimens, 38.5-76.4 mm SL from Trangan and Kobroor islands. It is superficially similar to M. albimarginata and M. patoti, but exhibits marked genetic separation, unique colour pattern features, and several slight morphological differences. Melanotaenia kolaensis, M. picta, and M. wokamensis n. spp. are described from 95 (17.9-78.8 mm SL), 51 (17.2-93.2 mm SL), and 156 (14.1-75.6 mm SL) specimens respectively, collected at Kola, Kobroor, and Wokam islands. They comprise a close-knit group allied to the “Goldiei” group (along with M. senckenbergianus), but are differentiated on the basis of live colour patterns and various genetic, morphometric, and meristic features.
MSNG 8133, Pimelodella gracilis (Valenciennes 1835), 87.19 mm SL, Argentina, Tucumán.