Taxonomy
The grouping of fish now deemed danionins has been the subject of constant research and speculation throughout the 20th century. Nearly all the fish classed within the genera ''Danio'' and ''Devario'' were originally placed in the genus ''Danio'' upon discovery. However, in the first part of the 20th century, George S. Myers split them into three genera, ''Danio'', ''Brachydanio'', and ''Daniops''. The sole species within Myers' ''Daniops'', ''D. myersi'', has long ago been found to be a synonym of ''Devario laoensis'', but his genus ''Brachydanio'' lasted for much longer, as it included most of the fish now classed as ''Danio'', whereas ''Danio'' included most of the fish now classed as ''Devario''. However, ''Danio dangila'' and ''Danio feegradei'', both of which had most of the characteristics of the ''Brachydanio'' (with the exception that they were much larger than ''Brachydanio'' species) were placed within ''Danios''. (Due to this and other misplacing, both ''Danio'' and ''Brachydanio'' were found to be paraphyletic by Fang Fang in 2003.). In 1941, H.M. Smith attempted to unite all the ''Brachydanios'' and ''Danios'' species into one genus on the basis of a fish from Thailand, which was supposed to bridge the gap. He downgraded both ''Danio'' and ''Brachydanio'' into subgenera and erected a new subgenus of ''Allodanio'' with one member, ''Allodanio ponticulus'', but Myers later pointed out that ''A. ponticulus'' was actually a member of the genus ''In the aquarium
They are generally active swimmers, occupying the top half of a tank and eat just about any type of aquarium food. They will not, however, generally eat plants or algae. Although boisterous and liable to chase each other and other fish, they are good community fish and do not generally attack each other or other fish, although they occasionally nip fins, and like most fish, eat eggs and any fish small enough to fit into their mouths. These fish are easily stressed by flowing water and bright light. They occur in stagnant water with pH values between 3 and 5 caused by peat, which accumulates from a dense canopy. Generally, this also results in them being subtropical with temperatures of often being fine; they are good jumpers, so a tight-fitting lid is recommended.Common names given to danionin species
Since 2004, many new danionins have been discovered, which do not yet have scientific names and many other species, previously known only to the scientific fraternity, have become available in aquarist shops. This has predictably led to total confusion as to the naming of some fish, with some species having up to five different common names in use and some common names being used for up to four different species.Danionin species scientific names
Individual danionin species are listed within the relevant pages for each genus, but many danionin species have been changed into different genera over the last decades, in some cases repeatedly; similarly, some species have been synonymised with other species and in some cases later unsynonymised, all of which has caused confusion.References
External links
* {{Taxonbar, from=Q5219663 Â Fishkeeping Fish of Southeast Asia