Barbs belong to the Cyprinidae family and are common fish tank inhabitants. Popular pet barbs include the tiger barb and cherry barb. They are brightly colored fish with rounded bodies and large coarse-looking scales. Among the species of barbs there are some common traits that distinguish the males from the females. This can help you select your barbs, whether you do, or do not, want to breed barbs.
Compare the colors of the barbs in the tank. Males are more brightly colored than the females.
Compare the body shape of the barbs. Females have larger and more rounded bodies. There are some exceptions to the size rule. For example, cherry barb males are larger than cherry barb females.
Watch for color changes in the fish. Male barbs may become brighter right before breeding. For example, male cherry barbs turn a brilliant red color before breeding.
Look for red coloring. Males tend to have more red than females. Females tend to have more gold or yellow coloring.
Watch the female lay eggs. This is surest way to determine that you do in fact have a female barb.