The threadfin rainbowfish or featherfin rainbowfish (''Iriatherina werneri'') is a

rainbowfish The rainbowfish or Melanotaeniidae is a family of small, colourful freshwater fish found in northern and eastern Australia, New Guinea (including islands in Cenderawasih Bay and Raja Ampat Islands in Indonesia), Sulawesi and Madagascar. The l ...

, the only species in the genus ''Iriatherina''. It is characterized by long beautiful fins, and is among the most attractive of the rainbowfishes. It is native to

freshwater Fresh water or freshwater is any naturally occurring liquid or frozen water containing low concentrations of dissolved salts and other total dissolved solids. Although the term specifically excludes seawater and brackish water, it does in ...

swamps and demersal or thickly vegetated areas of flowing waters, in tropical northern Australia and

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 ...

. It grows up to in length, but this does not include the Threadfin's long tail. Sexing is easy by examining fins: males have larger, gaudier finnage than females. Males also have more intense colours. When reproduction takes place eggs are scattered among the leaves of submerged vegetation, and hatch after7-10 days. The threadfin rainbowfish was described by Herman Meinkin in 1974 from

types Type may refer to: Science and technology Computing * Typing, producing text via a keyboard, typewriter, etc. * Data type, collection of values used for computations. * File type * TYPE (DOS command), a command to display contents of a file. * Ty ...

collected in

Merauke Merauke is a large town and the capital of the South Papua province, Indonesia. It is also the administrative centre of Merauke Regency in South Papua. It is considered the easternmost city in Indonesia. The town was originally called Ermasoe. ...

Irian Jaya 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 Torres ...

, Indonesia. Meinken honoured the

German German(s) may refer to: * Germany (of or related to) **Germania (historical use) * Germans, citizens of Germany, people of German ancestry, or native speakers of the German language ** For citizens of Germany, see also German nationality law **Ger ...

aquarium fish trader Arthur Werner, who collected the type, in the specific name. The generic name is a combination of ''Iri'' referring to Irian Jaya and ''atherina'', referring to the silverside genus '' Atherina'' as they were thought to be in the same family at the time of naming. Genetic studies have appeared to indicate that there may be significant genetic divergence between the different populations of threadfin rainbowfish that occur parapatrically in northern

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_ ...

and in the

Northern Territory The Northern Territory (commonly abbreviated as NT; formally the Northern Territory of Australia) is an Australian territory in the central and central northern regions of Australia. The Northern Territory shares its borders with Western Au ...

which would mean these populations were different species. It is likely that the New Guinea populations will be shown to be third species.

In the aquarium

In aquaria they are usually peaceful, they live preferably in groups of six or more. Because of their long fins they should obviously be kept in a tank without fin-nippers. They breed best in tanks without other species. The male courts the female by posturing in front of her repeatedly quickly raising then lowering the forward dorsal fin. The recommended male-to-female ratio is about 1:3, due to polygamous behavior of dominant male. Threadfin rainbowfish do well in aquariums of , however is preferred. They are best housed in a "species only" tank; meaning that the tank is reserved for the Threadfins alone. Because of their tiny mouths, they can be difficult to feed. They do well with live foods, such as baby brine shrimp, and the micrometre larval diets. They prefer water that is soft to moderately hard, slightly acidic ( pH 6.0–7.0), and with a temperature of .

References

* {{Taxonbar, from=Q2107345 threadfin rainbowfish Freshwater fish of Australia Freshwater fish of New Guinea Taxa named by Herman Meinken threadfin rainbowfish