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| Scaturiginichthys vermeilipinnis - photo© Günther Schmida |
Ivantsoff, Unmack, Saeed and Crowley, 1991
Red-finned Blue-eye
Description
Colours of both sexes are translucent to silvery with a plainly visible swim bladder; eyes are silvery-blue. Sexually mature males, in the reproductive mode, take on an attractive colouration. The males fins being edged with brilliant vermilion, hence their common name of Red finned Blue-eye.
Distribution
Scaturiginichthys vermeilipinnis is endemic to a single complex of springs associated with the Great Artesian Basin, Australia, located on Edgbaston Station, a sheep and cattle property located 35 km north-east of Aramac in central-western Queensland. The discovery of this species suggests that the blue-eye group may have had a much wider distribution than previously thought, and not just limited to coastal areas. Perhaps they are remnants of fish populations that existed when wetter conditions prevailed in central Australia.
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| Scaturiginichthys vermeilipinnis (natural habitat) - photo© Günther Schmida |
Habitat & Ecology
Edgbaston Springs occur in the upper reaches of Pelican Creek, a tributary at the head of the inland Lake Eyre catchment. Pelican Creek is ephemeral although some waterholes may persist between rainfall events. Uncontrolled GAB bores provide permanent water in the area including sections of Pelican Creek downstream of the natural springs. This complex currently contains 34 active springs (having at least some free water at the surface) scattered within an area of around 50 km².
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| Edgbaston Springs Habitat - photo© Adrian Tappin |
Most of the springs are very small, shallow, and marshy. The depth of the springs fluctuates with permanent springs usually around a depth of only 5 to 20 cm. The water is generally clear pH 7.8 to 8.0; Hardness around 150 ppm and well oxygenated. Water temperatures are extremely variable from spring to spring and within each spring. In May 1990 the temperatures varied from 7 to 28° Celsius. During May 1991 at 7.00 am water temperatures of 7 to 20°C were recorded in different parts of the springs. While at other times of the year minimum and maximum water temperatures of 3 and 38.5° Celsius have been recorded. Air temperatures of minus 3° up to 40° Celsius have been recorded in the area.
Scaturiginichthys vermeilipinnis is Australia's smallest freshwater fish reaching a maximum total length of around 30 mm. They have two dorsal fins, separated by a small gap, the first much smaller than the second. An egg-scatterer, generally spawning amongst aquatic plants and grasses. Eggs adhere to water plants and hatching occurs around 9-11 days at a temperature of 25° Celsius. Essentially a carnivore, feeding on a variety of terrestrial and aquatic insects, insect larvae, and small aquatic crustaceans. Probably possess both eurythermal and euryhaline characteristics, which are acquired by many desert fishes in response to a changing environment.
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| Chlamydogobius squamigenus - photo© Günther Schmida |
Remarks
Scaturiginichthys vermeilipinnis are Australia's most endangered freshwater fish species. They share their habitat with another equally endangered species (Chlamydogobius squamigenus), the Edgbaston Goby. Although population numbers of Scaturiginichthys vermeilipinnis in individual springs have varied since their discovery, specific population trends are not well known and they have disappeared completely from a number of springs. It is estimated that their numbers may range from a few hundred to a few thousand individuals.
Their continued existence is being threatened by the introduced mosquito fish Gambusia holbrooki and habitat destruction caused by harvesting water from the Great Artesian Basin, trampling and grazing by stock and feral animals, and modification of springs to provide for stock watering. Work is currently underway to increase their chances of survival with flow-on benefits to other fauna and flora endemic to that spring-group. A recent survey has found that sub-populations of this species are not healthy and potential threats are increasing. There are no longer any captive populations in existence!
© Copyright Adrian R. Tappin
Updated January, 2007.
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