Matt Clarke looks at a newly imported loach from the Mekong, Nemacheilus platiceps.
Scientific name: Nemacheilus platiceps, Kottelat, 1990.
Origin: Believed to be endemic to the Mekong basin, this species has been recorded
from Cambodia and Vietnam, where it was found at Trang Bom in the Soirap River drainage about 30 km east north-east of Ho Chi Minh city.
Size: Kottelat s 1998 paper, which described 20 new loaches, says that the species grows to 6 cm/21/4, but these fish were a fraction larger.
Diet: Should accept most foods ranging from flakes and small sinking pellets to frozen foods such as bloodworm, Daphnia and brineshrimp.
Water: These were in hard, alkaline water, but ideally they ought to be kept in relatively soft and slightly acidic conditions. As with all balitorids, the water will need to be very clean, well oxygenated and around 22-25C/71.5-77F.
Aquarium: According to Rainboth s Fishes of the Cambodian Mekong, Nemacheilus platiceps lives among decaying terrestrial vegetation in clear, shallow, slow-flowing pools in upland rivers and streams. However, Kottelat says that the species is found over a gravel substrate in moderate to rapid water.
Go for a smooth, gravel substrate and plenty of water-worn cobbles and boulders and bits of bogwood to provide shelter. Add beech, red oak or almond leaves to recreate the decaying terrestrial vegetation. They re best kept as a group.
Provide plenty of hiding places to minimise squabbling.
Identification: This balitorid loach is a member of the Nemacheilinae subfamily. The Nemacheilus genus contains over 70 species, many of which look very similar to platiceps, so these aren t the easiest of fish to identify.
N. platiceps should have around 15 irregular bars (these specimens had 16-19), which are darker along the edges and paler in the centre. The lips lack furrows, the lateral line is incomplete and the tail is forked and has unequal lobes.
Counting fin rays proved tricky; I counted 11 dorsal rays on my specimen along with six anal fin rays. This did not fit with the supposed 12-13 FishBase says the fish should have.
Steve Grant had a copy of the original description and kindly pointed out that it stated that the fish should have IV 8-9.5 branched dorsal rays, but since the description was only based on seven specimens, mine might fall outside the range of the type series. Steve said: The .5 refers to the last branched ray born by the same pterygiophore (the cartilage or bone on the outer end of which sit the median fin rays or spines and to which are attached the erector and depressor fin muscles), so you may in fact count 8-10, and five to six branched rays respectively.
If you add the hard leading rays as one (which are actually four fused together) with the 10 branched rays, that gives you your count of 11 rays.
Availability: These fish were imported by Wildwoods via a Thailand-based exporter. It s the first time I ve seen this species on sale in the UK. We photographed these ones back in February 2007.
Price: These were on sale for around 3.95.
This article was first published in the August 2007 issue of Practical Fishkeeping. Picture by Neil Hepworth.