The Siamese fighting fish, or Betta splendens, is just one of about 50 colorful species of betta fish that are enjoyed by aquarists worldwide. These fish are typically sold in individual bowls at aquarium stores and carnival midways because the males do not mingle well with others of the species. To select the best, choose fish with unblemished skin and fins that dart about vigorously when moved. Though they do not need a filtered tank to survive, they can benefit from one — as long as they are sharing space with fish that will let them establish their own territory somewhere in the tank. As with choosing any fish, it is important to fully inspect a beta before buying it to make sure there are no apparent abnormalities that could indicate illness.
The Betta splendens species, with its flowing and colorful fins, is renowned for being one of the more visually striking freshwater aquarium members. It is perhaps the most ubiquitous betta fish in aquarium outlets around the globe. This fish's disposition led to the name and a still-popular Asian ritual of placing two males in the same tank to see which one will live to see another meal. The native fish used for fighting, in Southeast Asian countries like Vietnam and Cambodia, have the most subdued colors and shortest fins for an edge in battle.
Betta fish do not always have the flowing skirts of the Siamese fighting fish. Aside from B. splendens and two subspecies with even more dramatic fins — the half moons and crown tails — all other bettas have cropped fins. These fish will have many of the same territory issues of B. splendens, but range in colors, from the deep translucent purple of B. anabatoides to the tidy black, tan and white of B. albimargarita.
When buying any betta fish, it is important to consider what fish will be with it in the tank. Male bettas, which tend to have showier fins than the females, must be kept away from other members of the same species. Males will fight to the death, and opposite sexes do not get along very well either, except when mating. Even female bettas will fight when not placed in a tank that allows each to secure adequate territorial shelter. Otherwise, bettas can cohabitate with several other tropical freshwater fish with subdued colors and fins, such as tetras, catfish and shrimp.
Apart from considerations of choosing good neighbors, buyers of betta fish must be aware of the various illnesses that can befall an aquarium fish before it even makes its way to their home. A full visual inspection of the fish should be performed before buying it, looking for any damage to the fins, growths or film on the skin or eyes, as well as overall discoloration or lack of motility. Any of these signs could indicate a deeper problem ahead for your tank.