Beaufortia sp. Xiajia

Habitat – Maintenance

Habitat

I was actually about to leave the biotope EW-CN 48-07 at Xiajia, located around 20 km before Lingyun (陵云) on the road to Baise (百色) when Wang Jing discovered something very small creping on the rocks in the shallow areas of the mountain torrent we were fishing in. The small creek belongs to the You River (右江) basin.

The small something turned out to be baby flat loaches! They were too tiny to employ our nets thus we used our bare hands to catch them. They were not very timid and we managed to catch 15 individuals of different sizes up to 15 mm.

The habitat was a small mountaineous stream at 616 m asl with high gradient, in average 1 m broad and 20 cm deep. There were some big boulders on the sandy bottom. The water was moving fast (in rapids), cristall clear and of potable quality. The creek was partially shady, due to overhanging shore vegetation (grass and bushes). We did not observe any submerse flora. 

Due to problems with my equipment I was not able to measure the water temperature, but here is the rest of the parameters I measured:

• pH               7.5
• Conductivity        82 µS/cm
• Hardness total        3 ºGH
• Carbonate hardness    3 ºKH
• Nitrite           < 0.3 mg/l

High oxygenium saturated water due to riffles and the high gradient.  

The Beaufortia were not dwelling directly in the fast lane, they preferred the more still areas with moderate current. In fact, we did not see one individual in fast flowing rapids. 

Pay attention to the patina and ‘aufwuchs’ on the rocks.

Biotope EW-CN 48-07 at Xiajia is characterized by big boulders with a smooth surface. Flat loaches generally have a preference for this kind of surfaces rather than rough ones. Very rough karst stone assemblages do not belong to their preferred habitats.

You can also gather the high gradient from the picture. 

Development related coloration and pattern phases

This new Beaufortia possesses different colorations and color patterns through its development to a matured individual. One is able to distinguish 3 different colorations (patterns); fry (TL up to 20 mm), intermediate and matured coloration. The pictures below show the different coloration-pattern phases and morphological changes. 

This pictures has been taken one month after the capture. The fish has a TL of less than 20 mm. I guess its age at 2 month.

The fish shows fry coloration which is different from juvenile (intermediate) and adult coloration. The beautiful orange peduncle coloration disappears when adult.

Please note the rudimentary adiposal crests which shows the close phylogenetic relationship to some members of Schistura.

Fish at the same age than picture above. Noteworthy are the underdeveloped pelvic fins at this stage. They will grow much bigger when matured. 

Next coloration stage; at this intermediate phase the orange caudal peduncle coloration fades off. There are now fine markings on the dorsal and caudal fin. The flanks commence to develop vertical stripes.  

Intermediate coloration phase; the head is ornamented by an irregular pattern of dark spots and fine lines. The head is dorsally more flattened. The fish appears broader, more brawny. The overall appearance is now very flat loach like.   

I assume that the individual on the right side shows more or less the mature coloration and pattern. The fish on the left side is in transition phase from intermediate to mature. 

Matured individuals show an irregular pattern of spots and stripes on the head and pectoral base running into a pattern of brownish vertical stripes of irregular width. 

This yet undescribed species whose initial description is in preparation is easily distinguished by the coloration pattern.

Aquarium maintenance

Following the conditions in their natural habitat one is able to educe appropriate measures to keep them healthy and in overall proper conditions in the tank. Excellent water, slightly alcaline, linked with a temperature not higher than 23 ºC and a high oxygen saturation are probably the most important factors to let them flourish. Furthermore they require somewhat current taking up waste into the filter and increase the oxygen level. Usually power heads are employed to generate current, but they also heat up the water. The aquarist has to find a way to keep the water temperature low; using power heads during the sommer months could result in an unappreciated high temperature. High temperature means the ability of the water to absorb oxygen is reduced, which could be lethal to the flat loaches.

There should be rocks with a smooth surface and sandy bottom introduced. Bizarre wooden roots are not welcome. Strong lighting or even better sun shine is very beneficial to a patina and some ‘aufwuchs’ on the rocks. In such a river setup only a few plants might survive; suitable are Java fern and almost all Anubias.

Beaufortia sp. ‘Xiajia’ behaves absolutely friendly to other tank mates. They show intraspecific aggression and have a precedence within the group. If too many individuals are kept in a too small tank, the weaker ones will be permanently detered from feeding, becaused they are chased off by the stronger ones. A number of 6 individuals are recommended for a 100 liter setup. 

Marco Endruweit, 2008-5-10