Rosy loach, Tuberoschistura arakanensis

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The tiny Rosy loach from Myanmar, is a species being sold under the apparently fictitious scientific name "Tuberoschistura arakanensis", says Matt Clarke.

Common name: Rosy loach, "Tuberoschistura arakanensis"

Scientific name: Believed to be undescribed.

Origin: Myanmar.

Size: A tiny loach, reaching just 2.5cm/1" in length.

Diet: Probably feeds on small crustaceans. Accepts most small frozen foods in captivity, including Daphnia, Cyclops, bloodworm, brineshrimp. Also takes flakes and tablets. It's an active fish that appears to feed almost continually. Newly imported specimens are typically very thin upon arrival.

Water: Adaptable, but prefers cooler water 22-24C.

Aquarium: The small size of the Rosy loach makes it suitable for the more compact aquarium - though it is active, so needs plenty of swimming space. It should be kept in a group, ideally in a densely planted tank to mimic the presumed habitat (see below).

Notes: The Rosy loach was first imported into the UK in September 2006, at the same time as the Celestial Pearl danio, Danio (formerly Celestichthys) margaritatus. Exporters have suggested that the two fish come from the same habitat - a group of ponds in a rapidly developing area of Hopong, where the natural vegetation has been cleared to make way for roads and housing estates.

This appears to be confirmed by Tyson Roberts in his paper describing the Celestial Pearl danio, which states that the Danio lives in sympatry with the snakehead Channa harcourtbutleri, a Microrasbora similar or identical to M. rubescens and a small "Yunnanilus species" (many believe this to refer to the Rosy loach). Other taxonomists who have seen photographs of the fish also thought they looked most like Yunnanilus, and having kept Y. brevis, I must admit this was also my first impression.

However, the Rosy loach is being imported under the name Tuberoschistura arakanensis. Although the Tuberoschistura genus is real, a species called arakanensis does not appear to have been described. The name appears to suggest that it came from the Arakan region of Myanmar, which is nowhere near the type locality of Danio margaritatus.

Habitat: If it is from the type locality of D. margaritatus, this fish lives in shallow (30cm deep) weed-choked ponds in a highland region of Myanmar in the town of Hopong. Roberts said that the ponds contained one or two species similar to Elodea and Anacharis. Collectively the pools the species live in may be numerous and widespread, but they are small and shallow, and as the PFK website has previously reported, overcollecting the Celestial Pearl danio has caused habitat destructing and reduced catches to very low levels.

Roberts said: "Depending on the number and extent of the ponds and their accessibility, such intensive collecting and the ecological disturbance accompanying it could constitute a serious threat to C. margaritatus and Yunnanilus sp. unless they are more widely distributed than known at this time." Further populations of D. margaritatus have since been found, but no mention has been made of the presence of the "Yunnanilus", making this a potentially controversial species.

Availability: On sale at Maidenhead Aquatics @ Peterborough, who were also one of the first retailers in the UK to acquire the species.

Price: £4.50

This article was first published in the March 2008 issue of Practical Fishkeeping magazine. It may not be reproduced without written permission.