Matt Clarke on Devario regina, yet another new danionin to arrive in the UK from south east Asia.
Common name: Queen danio
Scientific name: Devario cf regina (Fowler, 1934)
Origin: Museum records show that this species has been collected from Myanmar, Thailand, Laos and Malaysia. According to Talwar and Jhingran (1991), Devario regina is fast-flowing open mountain streams in the Mekong basin.
Size: Probably around 10cm/4" or so.
Water: This is a mountain stream fish, so don't keep it too warm. It's unfussy about water chemistry but should prefer a temperature in the low 20sC.
Diet: Flakes and granules, along with frozen bloodworm and daphnia are ideal.
Aquarium: Devario are active shoaling fish and come from turbulent and fast-flowing water, so make sure your pumps have a high turnover. They're apparently found over a sandy bottom in rocky streams. Although peaceful, larger Devario can be a little boisterous. Should mix well with barbs, danios and loaches. Always keep in a group of four or more so you can observe these fish behaving naturally.
Breeding: I managed to get my shoal of six to spawn within a week of obtaining them. (I am reliably informed by danionin fanatic Paul Rowntree that I may have been the first person in the UK to do this). I didn't notice that my fish had spawned until I saw about 100 tiny fry swimming near the surface. As I did not have a spare tank to transfer these to, some were consumed but many have remained for weeks, with little attention from the adults. The fry were taking finely crumbled flakes. Spawning was probably triggered by a drop in temperature - I turned the heaters off for the summer and did a cool water change, lowering the temperature to about 18-20C and allowing it to fluctuate with the room temperature. The heater will be turned on again in the autumn.
Identification: There are lots of newly imported Devario species around at the moment, including some undescribed ones, and they can be hard to tell apart, especially if the collection locality isn't known. A number of experts debated the identity of this one at Petfrd.com and the consensus is that it appears to be an atypical colour form of Devario regina, or a close relative, such as annandalei or affinis. D. regina does not normally have vertical bars near the cleithrum, though, and there are usually more logitudinal stripes than are present on this fish. D. regina should have 13 branched dorsal rays and 16-17 branched anal fin rays.
Availability: We photographed this fish at Frisby Aquatics in Hull a few months ago, and believe that the fish were originally imported by BAS in Bolton. Recently, exporters in Thailand have been offering D. regina as under the name Giant danio. This form is the stereotypical regina with more defined stripes and a blue base colour to the flanks.
Price: Expect to pay up to a fiver for one of these.