The rainbowfish or Melanotaeniidae is a
family
Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...
of small, colourful
freshwater fish
Freshwater fish are those that spend some or all of their lives in fresh water, such as rivers and lakes, with a salinity of less than 1.05%. These environments differ from marine conditions in many ways, especially the difference in levels of s ...
found in northern and eastern
Australia,
New Guinea
New Guinea (; Hiri Motu: ''Niu Gini''; id, Papua, or , historically ) is the world's second-largest island with an area of . Located in Oceania in the southwestern Pacific Ocean, the island is separated from Australia by the wide Torr ...
(including islands in
Cenderawasih Bay
Cenderawasih Bay ( id, Teluk Cenderawasih, "Bird of Paradise Bay"), also known as Sarera Bay ( id, Teluk Sarera) and formerly Geelvink Bay ( nl, Geelvinkbaai), is a large bay in northern Province of Papua, Central Papua and West Papua, New Gui ...
and
Raja Ampat Islands
Raja Ampat, or the ''Four Kings'', is an archipelago located off the northwest tip of Bird's Head Peninsula on the island of New Guinea, in Indonesia's Southwest Papua province. It comprises over 1,500 small islands, cays, and shoals surrounding ...
in Indonesia),
Sulawesi and
Madagascar
Madagascar (; mg, Madagasikara, ), officially the Republic of Madagascar ( mg, Repoblikan'i Madagasikara, links=no, ; french: République de Madagascar), is an island country in the Indian Ocean, approximately off the coast of East Africa ...
.
The largest rainbowfish
genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial n ...
, ''Melanotaenia'', derives from the ancient Greek ''melano'' (black) and ''taenia'' (banded). Translated, it means "black-banded", and is a reference to the often striking lateral black bands that run along the bodies of those in the genus ''Melanotaenia''.
Characteristics
The Melanotaeniidae is characterised by having their distal premaxillary teeth enlarged. They have a compressed body with the two
dorsal fin
A dorsal fin is a fin located on the back of most marine and freshwater vertebrates within various taxa of the animal kingdom. Many species of animals possessing dorsal fins are not particularly closely related to each other, though through c ...
s being separated but with only a small gap between them. There are 3–7 spines in the first dorsal fin while the second has 6–22 rays, with the first ray being a stout spine in some species, the
anal fin
Fins are distinctive anatomical features composed of bony spines or rays protruding from the body of a fish. They are covered with skin and joined together either in a webbed fashion, as seen in most bony fish, or similar to a flipper, as s ...
has 10–30 rays and, again, the first may be a stout spine in some species. The
lateral line is either weakly developed or absent. They have comparatively large scales and these number 28–60 in the lateral series. The
pelvic fin
Pelvic fins or ventral fins are paired fins located on the ventral surface of fish. The paired pelvic fins are homologous to the hindlimbs of tetrapods.
Structure and function Structure
In actinopterygians, the pelvic fin consists of two e ...
s are attached to the fish’s abdomen by a membrane which runs along the length of the innermost ray and this is a feature which can be used to separate rainbowfishes from silversides, although the membrane is easily torn. The majority of the species in this family demonstrate conspicuous
sexual dimorphism
Sexual dimorphism is the condition where the sexes of the same animal and/or plant species exhibit different morphological characteristics, particularly characteristics not directly involved in reproduction. The condition occurs in most an ...
, with the males usually being the more colorful sex and also showing an elongated median fin ray.
[
Most species of rainbowfish are less than in length, with some species measuring less than , while one species, ''Melanotaenia vanheurni'', reaches lengths of up to . They live in a wide range of freshwater habitats, including rivers, lakes, and swamps. Although they spawn all year round, they lay a particularly large number of eggs at the start of the local rainy season. The eggs are attached to aquatic vegetation, and hatch seven to 18 days later. Rainbowfish are generalized omnivores, feeding on small crustaceans, insect larvae, and algae.]
Melanotaenia, '' Pseudomugil'', and several other genera of rainbowfish include species that regularly appear in the aquarium trade. In the wild, some rainbowfish populations have been severely affected by the aggressive introduced eastern mosquitofish (''Gambusia holbrooki''), tilapia
Tilapia ( ) is the common name for nearly a hundred species of cichlid fish from the coelotilapine, coptodonine, heterotilapine, oreochromine, pelmatolapiine, and tilapiine tribes (formerly all were "Tilapiini"), with the economically most i ...
cichlids, and pollution.
Classification
Melanotaeniidae is divided into a number of subfamilies; these families have been considered by some authorities to separate families, but the 5th Edition of ''Fishes of the World
''Fishes of the World'' by the American Ichthyology, ichthyologist Joseph S. Nelson (1937–2011) is a standard reference for fish systematics. Now in its fifth edition (2016), the work is a comprehensive overview of the diversity and classificat ...
'' classifies these as subfamilies of a single family as they form a monophyletic
In cladistics for a group of organisms, monophyly is the condition of being a clade—that is, a group of taxa composed only of a common ancestor (or more precisely an ancestral population) and all of its lineal descendants. Monophyletic ...
group or clade. They are therefore classified as follows:
* Subfamily Bedotiinae Jordan
Jordan ( ar, الأردن; tr. ' ), officially the Hashemite Kingdom of Jordan,; tr. ' is a country in Western Asia. It is situated at the crossroads of Asia, Africa, and Europe, within the Levant region, on the East Bank of the Jordan Ri ...
& Hubbs, 1919 Madagascar rainbowfishes
** Genus '' Bedotia'' Regan
The family name Regan, along with its cognates O'Regan, O Regan, Reagan, and O'Reagan, is an Anglicized form of the Irish surname Ó Riagáin or Ó Ríogáin, from Ua Riagáin. The meaning is likely to have originated in ancient Gaelic ''ri' ...
, 1903
** Genus ''Rheocles
''Rheocles'' is a genus of Madagascar rainbowfish. ''Rheocles'' has a restricted distribution, being found only in certain forested freshwater habitats in the central and eastern highlands of Madagascar including the Nosivolo River. The genus ap ...
'' Jordan & Hubbs, 1919
* Subfamily Melanotaeniinae Gill, 1894 Rainbowfishes
** Genus '' Chilatherina'' Regan, 1914
** Genus ''Glossolepis
''Glossolepis'' is a genus of rainbowfishes from New Guinea.
Species
There are currently nine recognized species in this genus:
* '' Glossolepis dorityi'' G. R. Allen, 2001 (Doritys rainbowfish)
* ''Glossolepis incisus
The red rainbowfish or ...
'' M. C. W. Weber, 1907
** Genus '' Melanotaenia'' T.N. Gill, 1862
** Genus '' Cairnsichthys'' G. R. Allen, 1980
** Genus '' Rhadinocentrus'' Regan, 1914
** Genus '' Iriatherina'' Meinken, 1974
** Genus '' Pelangia'' G. R. Allen, 1998
* Subfamily Pseudomugilinae Kner, 1867 Blue-eyes
** Genus '' Kiunga'' G. R. Allen, 1983
** Genus '' Pseudomugil'' Kner, 1866
** Genus '' Scaturiginichthys'' Ivantsoff, Unmack, Saeed & Crowley, 1991
* Subfamily Telmatherininae Munro
A Munro () is defined as a mountain in Scotland with a height over , and which is on the Scottish Mountaineering Club (SMC) official list of Munros; there is no explicit topographical prominence requirement. The best known Munro is Ben Nevis ...
, 1958 Celebes rainbowfishes
** Genus '' Kalyptatherina'' Saeed & Ivantsoff, 1991
** Genus '' Marosatherina'' Aarn, Ivantsoff & Kottelat, 1998
** Genus ''Paratherina
''Paratherina'' is a genus of sailfin silversides endemic to the Indonesian island of Sulawesi.
Species
The currently recognized species in this genus are:
* '' Paratherina cyanea'' Aurich
Aurich (; East Frisian Low Saxon: ''Auerk'', West F ...
'' Kottelat, 1990
** Genus ''Telmatherina
''Telmatherina'' is a genus of sailfin silversides endemic to the Indonesian island of Sulawesi. They are restricted to the Malili Lake system, consisting of the large Matano and Towuti, and the small Lontoa (Wawantoa), Mahalona and Masapi. ...
'' Boulenger Boulenger is a surname. Notable people with the surname include:
* Benjamin Boulenger (born 1990), French footballer
* Edward George Boulenger (1888–1946), British zoologist, director of aquarium at London Zoo
* George Albert Boulenger (1858–1 ...
, 1897
** Genus ''Tominanga
''Tominanga'' is a genus of sailfin silversides endemic to the Indonesian island of Sulawesi.
Species
There are currently two recognized species in this genus:
* '' Tominanga aurea'' Kottelat, 1990
* '' Tominanga sanguicauda'' Kottelat
Maurice ...
'' Kottelat, 1990
Behaviour in captivity
Rainbowfish usually do best with tropical community fish, such as tetra
Terrestrial Trunked Radio (TETRA; formerly known as Trans-European Trunked Radio), a European standard for a trunked radio system, is a professional mobile radio and two-way transceiver specification. TETRA was specifically designed for use by ...
s, guppies, and other rainbowfish. However, two males may sometimes fight at breeding season if there are not enough females. Rainbowfish usually eat floating flakes in captivity, because in the wild they will often eat insects floating on the surface.
References
External links
ANGFA
– Australia New Guinea Fishes Association, an international organization responsible for the quarterly publication of the color journal ''Fishes of Sahul'' and a quarterly newsletter devoted to the keeping and discussion of native fishes in Australia and New Guinea (the geographical region known as Sahul)
Home of the Rainbowfish
– Adrian Tappin's extensive information pages which promote the aquarium keeping, study and conservation of the rainbowfish species of Australia and New Guinea, and provide free and valuable information to the general public
Rainbowfish Species
Easy to use information on keeping rainbowfish in the aquarium
Rainbowfish discussion forum
Rainbowfish discussion forum (mostly Europeans & Australians)
{{Taxonbar, from=Q1141512
Atheriniformes
Ray-finned fish families
Taxa named by Theodore Gill