It is some kind of butterfly loach, I'm not sure of the exact species, but I have one that looks very similar in my hillstream tank. A ten gallon should work fine, but they need cooler temps (I keep mine at room temp, and they seem to be doing great!) They also need a decent amount of current, high oxygen levels, and really good water quality (ammonia and nitrite should be 0, and nitrate should be less than 10-20ppm) They also need a well established tank, with some algae growth (I've never seen any of my butterfly loaches eat anything besides algae.) If you want anymore advice, feel free to ask!