Pseudomugil cyanodorsalis - photo© Neil Armstrong

Pseudomugil cyanodorsalis

Species Summary
Pseudomugil cyanodorsalis is a very colourful species and deserves a much better common name than 'Blueback Blue Eye' as suggested by Gerald Allen. The upper half of the males' body is metallic blue (similar to the Neon Tetra) and peppered with fine grainy melanophores. The lower half of the males' body is translucent to yellowish white. A single thin dark mid-lateral line runs from the base of the pectoral fin to the caudal fin. The first dorsal fin is translucent with an outer blackish border, and a small yellowish patch at the base near the last spine. The elongated anterior rays and outer edge of the second dorsal and anal fins are black. The remainder of the fin is creamy yellow or whitish. The caudal and pectoral fins are translucent or slightly yellowish with black outer edges. The body of the female is a semi-transparent silver-grey colour with translucent fins and white abdomen. Maximum size is around 3.5 cm. Pseudomugil cyanodorsalis were originally available in the Australian hobby in 1982 but failed to become established. Another wild-collection for the aquarium hobby was made in 1986 and today, they are widely distributed in the aquarium hobby all around the world.

Distribution & Habitat
Pseudomugil cyanodorsalis was first collected by Helen Larson (Northern Territory Museum) in 1981 near Darwin. A year later Gerald Allen (Western Australian Museum) found them in Crab Creek, 15 km east of Broome in Western Australia. In 1983, there were scientifically described by Allen and Sarti. They have been collected from around Broom and Wyndham in northern Western Australia. In the Northern Territory they have been recorded in coastal catchments around Darwin and the Mary River. They have also been collected from Melville Island. In Queensland they have been collected from the Norman River in the Gulf of Carpentaria. They are probably widely distributed in estuarine and coastal freshwater habitats across northern Australia and southern New Guinea. Pseudomugil cyanodorsalis are sympatric with Pseudomugil inconspicuus, and are found together in at least one locality (Woods Inlet) near Darwin.

Pseudomugil cyanodorsalis are euryhaline and tolerate a wide range of ecological conditions. Although more commonly found in small brackish estuarine creeks, they also inhabit pure freshwater habitats, especially during the wet season. During the wet season, freshwater flowing into these habitats dilutes the waters to fresh. Water thus varies from saline through brackish to fresh. However, habitat preference appears to be mangrove-lined muddy brackish creeks, where they are commonly found in large numbers. They have been found in hypersaline waters (28~40 ppt) and at temperatures of 22~39°C.

Pseudomugil cyanodorsalis - photo© Gunther Schmida

Literature
Allen, G. R. and N. Sarti (1983). Pseudomugil cyanodorsalis, une nouvelle espèce de blue-eye (Melanotaeniidae) d'Australie nord-occidentale. Revue française d'Aquariologie 10(2): 47-50.

Allen, G.R. (1989). Freshwater fishes of Australia. T.F.H. Publications, Inc., Neptune City, New Jersey.

Allen G. R. (1995). Rainbowfishes in Nature and in the Aquarium. (Tetra-Verlag: Germany)

Allen, G.R., S.H. Midgley and M. Allen (2002). Field guide to the freshwater fishes of Australia. Western Australian Museum, Perth, Western Australia.

Fukada, M. (1998). Pseudomugil cyanodorsalis. ANGFA Bulletin 39:10-11.

Hansen, B. (1990). Pseudomugil cyanodorsalis. Fishes of Sahul 6(1): 249-252.

© Copyright Adrian R. Tappin
Updated December, 2008.