''Mogurnda adspersa'' (commonly known as the southern purple-spotted gudgeon) is a species of endangered

gudgeon A gudgeon is a socket-like, cylindrical (i.e., ''female'') fitting attached to one component to enable a pivoting or hinging connection to a second component. The second component carries a pintle fitting, the male counterpart to the gudgeon, ...

that is

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

to south-eastern mainland Australia (the states of

South Australia South Australia (commonly abbreviated as SA) is a state in the southern central part of Australia. It covers some of the most arid parts of the country. With a total land area of , it is the fourth-largest of Australia's states and territories ...

New South Wales ) , nickname = , image_map = New South Wales in Australia.svg , map_caption = Location of New South Wales in AustraliaCoordinates: , subdivision_type = Country , subdivision_name = Australia , established_title = Before federation , es ...

and

Victoria Victoria most commonly refers to: * Victoria (Australia), a state of the Commonwealth of Australia * Victoria, British Columbia, provincial capital of British Columbia, Canada * Victoria (mythology), Roman goddess of Victory * Victoria, Seychelle ...

and

Queensland ) , nickname = Sunshine State , image_map = Queensland in Australia.svg , map_caption = Location of Queensland in Australia , subdivision_type = Country , subdivision_name = Australia , established_title = Before federation , established_ ...

). The fish is brown, although the shade becomes lighter near its

abdomen The abdomen (colloquially called the belly, tummy, midriff, tucky or stomach) is the part of the body between the thorax (chest) and pelvis, in humans and in other vertebrates. The abdomen is the front part of the abdominal segment of the torso. ...

. Spots of various colours occur on its sides. After a dramatic population decline in the late 20th century, the fish was thought to be

locally extinct Local extinction, also known as extirpation, refers to a species (or other taxon) of plant or animal that ceases to exist in a chosen geographic area of study, though it still exists elsewhere. Local extinctions are contrasted with global extinct ...

in several areas, but was rediscovered both in South Australia and Victoria in the 21st century. Various state governments, the (

Commonwealth Government The Australian Government, also known as the Commonwealth Government, is the national government of Australia, a federal parliamentary constitutional monarchy. Like other Westminster-style systems of government, the Australian Government i ...

) Murray-Darling Basin Authority, and various volunteer organisations have been taking measures to increase the fish's numbers.

Description

''Mogurnda adspersa'' is

countershaded Countershading, or Thayer's law, is a method of camouflage in which an animal's coloration is darker on the top or upper side and lighter on the underside of the body. This pattern is found in many species of mammals, reptiles, birds, fish, and ...

dark brown on top, with its colour becoming progressively lighter on the sides and underside, where it is light brown or cream. The fish has three red bars on each cheek, and red, purple, black, and white spots along its sides. These spots are more visible when it is breeding. It is typically long, although it can grow up to .

Distribution and habitat

The southern purple-spotted gudgeon is

to southeastern

Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...

, particularly the Murray-Darling basin and coastal drainages northeast of the Clarence River. It is a

benthic The benthic zone is the ecological region at the lowest level of a body of water such as an ocean, lake, or stream, including the sediment surface and some sub-surface layers. The name comes from ancient Greek, βένθος (bénthos), meaning "t ...

fish, and is usually found in calm rivers or creeks. It swims among underwater plants, branches, and rocks. CC-BY icon

Text may have been copied from this source, which is available under
Attribution 3.0 Australia (CC BY 3.0 AU)
licence.

Feeding

The fish feeds on small fish, plants, and other assorted animals, such as shrimp, worms, tadpoles, insects larvae, and small crustaceans.

Breeding

During the breeding season, which generally spans from November to March, the female fish lays multiple batches of 30–1,300 eggs. The eggs are laid on underwater objects and plants. After the eggs are laid, the male fish guards the eggs and fans them with his fins. The young fish hatch from the eggs after 3–9 days.

Conservation status

, ''M. adspersa'' was classified as

threatened Threatened species are any species (including animals, plants and fungi) which are vulnerable to endangerment in the near future. Species that are threatened are sometimes characterised by the population dynamics measure of ''critical depensat ...

(regionally extinct) in Victoria,

endangered An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching and inva ...

in New South Wales, and critically endangered in South Australia. It is not considered threatened in Queensland. The fish's

conservation status The conservation status of a group of organisms (for instance, a species) indicates whether the group still exists and how likely the group is to become extinct in the near future. Many factors are taken into account when assessing conservation ...

has not been evaluated by the

IUCN The International Union for Conservation of Nature (IUCN; officially International Union for Conservation of Nature and Natural Resources) is an international organization working in the field of nature conservation and sustainable use of natu ...

. Though common in southeastern Australia, its numbers sharply declined in the 1980s, due to the introduction of predatory fish, lack of food, and changing water levels, which interfered with the fish's breeding. The fish was feared extinct in the

Murray–Darling Basin The Murray–Darling basin is a large geographical area in the interior of southeastern Australia, encompassing the drainage basin of the tributaries of the Murray River, Australia's longest river, and the Darling River, a right tributary of ...

for many years, and in the state of South Australia for over 30 years, before being rediscovered at the

wetland A wetland is a distinct ecosystem that is flooded or saturated by water, either permanently (for years or decades) or seasonally (for weeks or months). Flooding results in oxygen-free (anoxic) processes prevailing, especially in the soils. The ...

in the lower reaches of the

Murray River The Murray River (in South Australia: River Murray) (Ngarrindjeri: ''Millewa'', Yorta Yorta: ''Tongala'') is a river in Southeastern Australia. It is Australia's longest river at extent. Its tributaries include five of the next six longest r ...

in 2002.

Text may have been copied from this source, which is available under
Attribution 3.0 Australia (CC BY 3.0 AU)
licence. The population plunged during the 2009–2010 drought, again threatening local extinction, but its continued existence in the area was ensured by a

captive breeding Captive breeding, also known as captive propagation, is the process of plants or animals in controlled environments, such as wildlife reserves, zoos, botanic gardens, and other conservation facilities. It is sometimes employed to help species that ...

program at

Urrbrae Agricultural High School Urrbrae Agricultural High School is a public high school in the Australian state of South Australia, with approximately 1,016 students. The school is located in the Adelaide suburb of Netherby, about south-east of the Adelaide city centre. ...

, Alberton Primary School and Nature Glenelg Trust's Berri site. 500 fish were able to be returned to the wetlands by October 2015. In an effort to increase the fish's abundance, the

New South Wales Department of Primary Industries The New South Wales Department of Primary Industries (DPI) is an agency of the New South Wales Government, responsible for the administration and development for agriculture, fisheries, aquaculture, forestry, and biosecurity in New South Wales. ...

instituted a captive-breeding program, in hopes of eventually releasing the more "genetically variable" fish into the wild, where they can reproduce with the remaining wild populations and recover from their previous population decline by "recover nggenetic variation". The fish was declared to be

in Victoria in 1998. In 2018, two of the fish were found in wetlands in Victoria, and researchers started looking for more. In March 2021 it was reported that 66 more were found, living in a colony in a thickly reeded area. Some of the fish were being taken to breeders to help increase the population in the

Kerang Kerang is a rural town on the Loddon River in northern Victoria in Australia. It is the commercial centre to an irrigation district based on livestock, horticulture, lucerne and grain. It is located north-west of Melbourne on the Murray V ...

lakes area and the Murray.

References

External links

* {{Taxonbar, from=Q1254918 Eleotridae Mogurnda Endangered fauna of Australia Freshwater fish of Australia Fish described in 1878