Rasboras are a group of fishes in the family Cyprinidae, which includes the carps and minnows — and many of them are excellent aquarium fish. In general, rasboras are streamlined, fast-moving fish that do best in schools and in thickly planted tanks.
Two rasboras that do well in the aquarium are the red line or brilliant rasbora (Rasbora borapetensis) and scissortail rasbora (Rasbora trilineata). Both the brilliant and the scissortail were originally found in Asia in the Mekong River, in the Malay Peninsula, and on Sumatra and Borneo. All of these fish in the hobby today have been commercially raised, and virtually none of them are taken from the wild any longer.
The torpedo-shaped brilliant rasbora can measure up to about 2 to 3 inches long. The body is a dull silver color, with a slight greenish tinge as the fish matures. There is a solid black line running along the side of the fish and a large red spot where the tail meets the body. The scissortail rasbora is a little smaller, usually topping out at 21/2 inches. The entire body is silver with a pale gold overtone, and the tail has a large black stripe on both the upper and lower lobes. The scissortail gets its name from the fact that when it swims, the two black marks on the tail move towards each other, giving the impression of scissors closing.
Care and Feeding
Both of these rasboras require the same conditions, so what we mention here applies to both the brilliant and the scissortail rasbora. They are hardy, easy to take care of and make excellent community tank fish. They will not bother any other fish and are fast enough that other fish usually will not bother them. Both do best in a long tank with a lot of swimming room and in as large of a school as possible, preferably six fish or more; if both the brilliant and the scissortail rasbora are kept together, they will often school together, since they are so similar. Densely plant the back and sides of the tank, as these rasboras like to hover in plant thickets when they are resting. Mostly they are on the move, swimming all over the tank, which explains why they need a long tank with plenty of open swimming room.
The brilliant and the scissortail rasbora require excellent water quality, so a good filter system that removes particulate matter and maintains the nitrogen cycle well is very important. I recommend some kind of outside canister filter, as the fish enjoy the water movement from the return of this type of filter. As for water parameters, these fish prefer a neutral pH of 7.0 and moderate hardness, though they can both adjust to any pH between 6.5 and 7.5, and hardness up to 10. Temperature for both should be between 72 and 78 degrees Fahrenheit. Since the brilliant or scissortail rasboras in your local fish store have been raised commercially, they will eat just about anything offered to them. Feed them a couple of different dry prepared flake foods, and supplement with some frozen or freeze-dried treats (bloodworm, brine shrimp or Mysis shrimp) two or three times a week. They are always eager feeders, and if they are not the first ones up to the surface for the food, something is wrong with the tank. Feed them two or three times a day as much as they will consume in two or three minutes.
Both the brilliant and the scissortail rasbora breed freely, and both breed in exactly the same manner. Use a 10- or 15-gallon tank with only a heater and small sponge filter. Condition the male and female separately; you can tell them apart because the males are very slender, and the females are fatter, especially when they fill up with eggs. When conditioning the fish for breeding, live food is best, but they will come into form just fine with frozen bloodworm and Mysis shrimp. The breeding tank should have dense thickets of plants and/or spawning mops, since the parents will eat the eggs immediately. In fact, these two rasboras have a reputation for having small spawns of eggs and eating them as soon as they drop them.
After conditioning the two sexes separately, introduce them into the breeding tank in the early evening. They will usually spawn at first light the next morning. You have to look carefully for eggs, and if you do find some, remove the parents. The eggs hatch in about two days, then the babies are free-swimming in another two or three days, depending on temperature — at warmer temperatures, the eggs hatch faster and the fry grow more quickly. As with any other egg-scatterer, the babies require very fine food, such as commercial egglayer baby foods, green water or infusoria. After a few days to a week on the small foods, the babies should be able to eat live baby brine shrimp and then eat standard dry prepared foods. Doing frequent water changes will keep the water conditions good and the babies growing well. Don’t crowd the babies, and by the time they are three-fourths of an inch long, keep no more than two or three fish per gallon.
Because the brilliant and scissortail rasboras have been farmed in Florida, they are an easy addition to a freshwater aquarium. These friendly rasboras can provide you with interesting schooling behavior and babies if you keep them happy. So if you have a heavily planted tank that needs some inhabitants, consider these two easy rasboras.