Genus
Sewellia
- Species
- 8
- Photographed
- 8 of 8
- Difficulty rated
- 8 of 8

Sewellia albisuera
Freyhof, 2003
It's been suggested that these two may represent the same species but this appears not to be the case. When describing S. albisuera Freyhof (2003) used a series of specimens collected in 2000 plus some larger, spotted fish which had been collected in 1999 and preserved in New York. Although he noticed differences in dorsal patterning between the two series these weren't considered sufficient to s...

Sewellia elongata
Roberts, 1998
This species appeared in the trade during 2010 and its identity has been confirmed to us by Thai exporter and aquarist Kamphol Udomritthiruj who collects it from the Se Kong system for the aquarium hobby. To date only subadult specimens have reached the western market.

Sewellia lineolataTiger Hillstream Loach
Valenciennes, 1846
S. lineolata was first recorded by Diard over 150 years prior to its 'rediscovery' in the early-1990s. It became available to the aquarium trade in the mid-2000s and swiftly established itself as one of the more popular balitorids in the hobby due to its attractive body markings and ease of breeding. It's also sold under the names 'reticulated hillstream loach', 'Vietnamese hillstream loach' and 'gold ring butterfly sucker'. It's difficult to...

Sewellia sp. 'SEW01'Spotted Butterfly Loach
authority not recorded
This is one of the more readily-available members of the genus and popularly referred to as S. sp. 'spotted' or S. sp. 'special'. It's superficially similar in appearance to S. albisuera but in that species body patterning consists of a network of irregular dark lines forming a complicated series of reticulations vs. many small, light spots on a dark background in S. sp. 'SEW01'. It's been suggested that these two may represent the same species but this...

Sewellia sp. 'SEW02'
authority not recorded
This species first became available in early 2009 and was initially identified as S. breviventralis (Freyhof and Serov, 2000) because there is a clear space between the pelvic and anal fins and body patterning is vaguely similar to that species, and also appears quite similar to S. elongata (Roberts, 1998) and S. sp. 'SEW03'. It does not fully match the original descriptions of either, however, and therefore remains in need of identification.

Sewellia sp. 'SEW03'
authority not recorded
This fish first became available in early 2009 and was initially identified as S. breviventralis (Freyhof and Serov, 2000). However it cannot be that species because there is no discernible gap between pelvic and anal fins, which also discounts the possibility of it being S. elongata (Roberts, 1998). It therefore remains unidentified and is often imported in mixed batches with S. sp. 'SEW02', which it also resembles closely.

Sewellia sp. 'SEW04'
authority not recorded
This fish has thus far only been imported among shipments of S. sp. 'SEW02' and S. sp. 'SEW03'. It doesn't appear to correspond to any known member of the genus and may be undescribed. Prior to the mid-1990s S. lineolata was the only species in the genus but an upturn in surveys of fresh water fauna in Vietnam and Laos has resulted in the discovery of various new taxa, several of which remain undescribed.

Sewellia speciosa
Roberts, 1998
This species first became available in early 2010 and sometimes appears on trade lists under the vernacular names 'Laos sucker' or 'Laos Sakura sucker'. It's distinguishable from other members of the genus by the following combination of characters: body spotted and without stripes; no concentric bands on paired fins; origin of pelvic-fin below origin of dorsal-fin; origin of pectoral-fin posterior to corner of mouth; pelvic fin reaching origin of anal fin; small elevated ...