Scissortail Rasbora

The scissortail rasbora owes its name to its deeply forked caudal fin, each lobe marked with black and yellow bars that seem to open and close like a pair of scissors as the fish swims. The slender, silvery body carries a fine dark stripe along its flank. Long placed in the Cyprinidae, it is now assigned to the Danionidae. It inhabits the Chao Phraya and lower Mekong basins across Laos, Thailand and Cambodia, together with Peninsular Malaysia and the Greater Sunda Islands, keeping to open water near the surface in lakes, swamps, slow river reaches, lowland canals and waterfall pools. Wild populations are in marked decline. Sold at three or four centimetres, it grows to around fifteen: that is the trap. Scientific surveys record a maximum nearer 13 cm total length, with adults usually between 5 and 10.5 cm. A gregarious shoaler, it needs six companions at the very least and a tank at least 120 cm long — Seriously Fish states 255 litres — as swimming length matters more than volume. Soft water at 22-25 °C and open swimming lanes suit it. An omnivore, it takes dry food but colours up on daphnia and brine shrimp. Breeding, which requires darkness and produces nonadhesive eggs, is rarely achieved at home.