Red dwarf rasbora (''Microrasbora rubescens'') is a
species
In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...
of
cyprinid
Cyprinidae is a family of freshwater fish commonly called the carp or minnow family. It includes the carps, the true minnows, and relatives like the barbs and barbels. Cyprinidae is the largest and most diverse fish family and the largest ver ...
Shan State
Shan State ( my, ရှမ်းပြည်နယ်, ; shn, မိူင်းတႆး, italics=no) also known by the endonyms Shanland, Muang Tai, and Tailong, is a state of Myanmar. Shan State borders China (Yunnan) to the north, Laos ( ...
in
Myanmar
Myanmar, ; UK pronunciations: US pronunciations incl. . Note: Wikipedia's IPA conventions require indicating /r/ even in British English although only some British English speakers pronounce r at the end of syllables. As John Wells explai ...
. It belongs to the
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 nom ...
''
Microrasbora
''Microrasbora'' is a genus of small fishes. The generic name means "small Rasbora", however these are more closely related to the danios than rasboras. They inhabit freshwater in Myanmar and Yunnan, China.
Taxonomy
''Microrasbora'', until rec ...
'', which contains two small species of
danionin
The danionins are a group of small, minnow-type fish belonging to the family Cyprinidae. Members of this group are mostly in the genera '' Danio'', '' Devario'', and ''Rasbora''._They_are_primarily_native_to_the_ s_...''._They_are_primarily_nati ...
s. 2009. Molecular phylogenetic interrelationships of the south Asian cyprinid genera ''Danio'', ''Devario'', and ''Microrasbora'' (Teleostei, Cyprinidae, Danioninae). Zoologica Scripta 38:237-256.
Description
The dwarf red rasbora reaches up to in length. Its
meristics Meristics is an area of ichthyology and herpetology which relates to counting quantitative features of fish and reptiles, such as the number of fins or scales. A meristic (countable trait) can be used to describe a particular species of fish, or us ...
are that there are 2 spines and 6-7 soft rays in the
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 ...
and 3 spines and 10-12 soft rays in the anal fin. The females are less instensly coloured than the males and are larger and have a much deeper body.
Habitat
The dwarf red rasbora is endemic to Lake Inle which is situated in a valley where the rocks form a karst and which lies 900m above sea level in the Shan Plateau region of Shan State. Within the lake this species can be found in the midwater and in the marginal waters of Lake Inle where it is associated with submerged vegetation and forms large schools.
Conservation
The red dwarf rasbora is exploited for the aquarium trade and it is thought this may have some impact on the population. It is also threatened by the introduction of exotic fish species to the lake, particularly ''
Parambassis
''Parambassis'' is a genus of freshwater fish in the Asiatic glassfish family Ambassidae of order Perciformes. The type species is the Iridescent glassy perchlet (''Ambassis apogonoides''). These fishes originate mostly from Southeast Asia, bu ...
'' and ''
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 ...
'' species, which act as both predators on and competitors with the red dwarf rasbora. In addition the lake has been polluted from a number of sources, especially from the growing human population in settlements around the lake, while sedimentation and agricultural runoff enters the lake from its drainage basin. The invasive
water hyacinth
''Pontederia crassipes'' (formerly ''Eichhornia crassipes''), commonly known as common water hyacinth is an aquatic plant native to South America, naturalized throughout the world, and often invasive outside its native range.