Melanotaenia duboulayi
Encyclopedia
The Crimsonspotted Rainbowfish (Melanotaenia duboulayi), known less commonly as the Duboulay's rainbowfish, is a species of freshwater rainbowfish
endemic to eastern Australia
. M. duboulayi has also been kept in aquariums since the early 20th century, and is the original Australian Rainbowfish.
. It was scientifically described as Atherinichthys duboulayi by Castelnau in 1878. It was later known as Nematocentris fluviatilis and Melanotaenia fluviatilis. It was reclassified as Melanotaenia splendida fluviatilis following a review of the rainbowfish group by Allen in 1980. The current scientific name, Melanotaenia duboulayi, given by Crowley, et al. in 1986, is a result of the study of early stages of life. This study separated M. splendida fluviatilis into two species, M. duboulayi from the eastern coastal drainage systems of northern New South Wales and southern Queensland
, and M. fluviatilis from the inland Murray-Darling basin
system west of the Great Dividing Range
.
s very close together, with the first much smaller than the second. The fin colours are variable from clear, yellowish to red, with red flecks and dark margins which become intensely black in males during spawning activities. Larger males are distinguished from females by their brighter colours and can be identified from the elongation of posterior rays in the second dorsal and anal fins. Females have rounded dorsal and anal fins, which are smaller and lack the dark edges. A prominent spot of crimson red is seen on the operculum. Generally, the body is silvery-blue or green ranging through deep bluish or yellow tones. The scale rows are marked with narrow yellow lines and overlaid with orange to brilliant red. They exhibit considerable colour variations over a wide geographical range.
, and in captivity they eat flake food. They like open water and may form small groups around submerged logs and sub-surface vegetation.
Spawning occurs prior to summer rains, and eggs adhere to filamentous sub-surface vegetation and floating plant roots.
in 1927, and it went from there to North America
. In 1930 it was found as an escapee in the Mississippi River
.
In their native range, crimsonspotted rainbowfish are also released into Australian dams to control mosquitoes, with emphasis on using local wild stock to prevent endemic variants of M.duboulayi from being lost by genetic
contamination from non-local forms.
Rainbowfish
The rainbowfish are a family of small, colourful, freshwater fish that are found in northern and eastern Australia and New Guinea and in the Southeast Asian islands....
endemic to eastern Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
. M. duboulayi has also been kept in aquariums since the early 20th century, and is the original Australian Rainbowfish.
Taxonomy
Melanotaenia duboulayi was initially collected by Duboulay (du Boulay) in 1870s from the Richmond River in northern New South WalesNew South Wales
New South Wales is a state of :Australia, located in the east of the country. It is bordered by Queensland, Victoria and South Australia to the north, south and west respectively. To the east, the state is bordered by the Tasman Sea, which forms part of the Pacific Ocean. New South Wales...
. It was scientifically described as Atherinichthys duboulayi by Castelnau in 1878. It was later known as Nematocentris fluviatilis and Melanotaenia fluviatilis. It was reclassified as Melanotaenia splendida fluviatilis following a review of the rainbowfish group by Allen in 1980. The current scientific name, Melanotaenia duboulayi, given by Crowley, et al. in 1986, is a result of the study of early stages of life. This study separated M. splendida fluviatilis into two species, M. duboulayi from the eastern coastal drainage systems of northern New South Wales and southern Queensland
Queensland
Queensland is a state of Australia, occupying the north-eastern section of the mainland continent. It is bordered by the Northern Territory, South Australia and New South Wales to the west, south-west and south respectively. To the east, Queensland is bordered by the Coral Sea and Pacific Ocean...
, and M. fluviatilis from the inland Murray-Darling basin
Murray-Darling Basin
The Murray-Darling basin is a large geographical area in the interior of southeastern Australia, whose name is derived from its two major rivers, the Murray River and the Darling River. It drains one-seventh of the Australian land mass, and is currently by far the most significant agricultural...
system west of the Great Dividing Range
Great Dividing Range
The Great Dividing Range, or the Eastern Highlands, is Australia's most substantial mountain range and the third longest in the world. The range stretches more than 3,500 km from Dauan Island off the northeastern tip of Queensland, running the entire length of the eastern coastline through...
.
Description
Male M. duboulayi reach maximum lengths of 12 centimetres (4.7 in), but are usually less than 10 centimetres (3.9 in) while the females are usually smaller. They have a slender and compressed body shape. Crimsonspotted rainbowfish have two dorsal finDorsal fin
A dorsal fin is a fin located on the backs of various unrelated marine and freshwater vertebrates, including most fishes, marine mammals , and the ichthyosaurs...
s very close together, with the first much smaller than the second. The fin colours are variable from clear, yellowish to red, with red flecks and dark margins which become intensely black in males during spawning activities. Larger males are distinguished from females by their brighter colours and can be identified from the elongation of posterior rays in the second dorsal and anal fins. Females have rounded dorsal and anal fins, which are smaller and lack the dark edges. A prominent spot of crimson red is seen on the operculum. Generally, the body is silvery-blue or green ranging through deep bluish or yellow tones. The scale rows are marked with narrow yellow lines and overlaid with orange to brilliant red. They exhibit considerable colour variations over a wide geographical range.
Behaviour
M.duboulayi is omnivorous. Their diet comprises all kinds of foods, especially invertebrates and algaeAlgae
Algae are a large and diverse group of simple, typically autotrophic organisms, ranging from unicellular to multicellular forms, such as the giant kelps that grow to 65 meters in length. They are photosynthetic like plants, and "simple" because their tissues are not organized into the many...
, and in captivity they eat flake food. They like open water and may form small groups around submerged logs and sub-surface vegetation.
Spawning occurs prior to summer rains, and eggs adhere to filamentous sub-surface vegetation and floating plant roots.
Domestication
Amandus Rudel introduced the species to international aquarium hobbyists when he sent specimens to GermanyGermany
Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...
in 1927, and it went from there to North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
. In 1930 it was found as an escapee in the Mississippi River
Mississippi River
The Mississippi River is the largest river system in North America. Flowing entirely in the United States, this river rises in western Minnesota and meanders slowly southwards for to the Mississippi River Delta at the Gulf of Mexico. With its many tributaries, the Mississippi's watershed drains...
.
In their native range, crimsonspotted rainbowfish are also released into Australian dams to control mosquitoes, with emphasis on using local wild stock to prevent endemic variants of M.duboulayi from being lost by genetic
Genetics
Genetics , a discipline of biology, is the science of genes, heredity, and variation in living organisms....
contamination from non-local forms.