Betta splendens

Common Names: Betta, Siamese fighting fish

Type Locality: Mae Nam Chao Phyraya, Thailand

Range: Mekong basin in Thailand, Cambodia, and Vietnam, introduced and established into several Southeast Asian and Latin American countries

Taxonomic Troubles: This fish has always been Betta splendens, but it has seen major revision in its higher taxa, such as family. It is currently an osphronemid, not an anabantid, an anabantoid, or a belontid, despite sometimes long-term traditions.

Size: 6.5 cm TL (2.5 inches); there is a "giant" mutation in domesticated strains that causes growth to 10 to 15 cm (4 to 6 inches).

Preferred Water Chemistry: Tropical freshwater, prefers a temperature around 27°C (80°F); will tolerate any non-extreme pH and hardness.

Difficulty: Extremely hardy.

Tank Setup: The ideal setup for a betta is a well-planted tank with mild-mannered tankmates like small tetras or small rasboras. Only one male should be kept per tank; females usually get along well. Even moderate currents can overwhelm a betta, so a quiet, gently fi

Feeding: Feeds primarily on tiny invertebrates in the wild, will readily accept all types of captive fare.

Breeding: The quintessential bubblenester, the betta breeds readily. Live foods quickly condition the female, who is courted by the male to join him under his nest of bubbles. The cycle of embrace-stupor-recover-retrieve egss is repeated until the female is empty and the nest is full. The male then drivers her off and tends the eggs until they hatch. The major challenge in breeding bettas is in providing each male an individual container; as soon as they are sexable, the males must be housed singly.

Fish Description

It is no exaggeration to say that bettas have been bred in every color and in many combinations of colors. They span the full spectrum, from white to black, from red to violet, plus shimmering metallic colors. Finnage ranges from the original short fins to veiltails, halfmoon tails, comb tails, crown tails, and even double tails.


Soon after the betta was domesticated for use in fighting contests in old Siam, long-finned decorative strains began to be developed, and this has continued to the present day, when hybridization with other Betta species has increased the color variety. The betta is recognized even by many outside the aquarium hobby. This is in part due to the unfortunate fashion of maintaining bettas in vases, which are sorely inadequate habitats for these magnificent fish. The minimum volume for a single betta is one gallon, preferably two or three, and room temperatures are not adequate, unless your rooms are kept at tropical temperatures in the high 70s and low 80s. Without filtration a betta tank requires very frequent water changes. This fish's ability to breathe air and therefore not asphyxiate immediately in a small volume of water often condemns it to a lingering death from ammonia poisoning in a fetid puddle in some bowl or vase. Kept properly, these are magnificent fish, and though short-lived, will grace your tanks for two or three years.

A popular method of exhibiting bettas is to partition a tank and place various males in individual compartments. Some use opaque partitions, while others prefer to use transparent dividers so they can see the gill and fin flaring displays. However, when they are able to see each other, the males quickly habituate, and their displays become infrequent. Many shopkeepers have their cake and eat it too by placing index cards between individual male's bowls. When a customer shows interest in a fish, removing a card initiates a full-blown display, showing off the fish to its best advantage.

Betta splendens has been in the hobby for almost a century and has been popular the whole time. If anything, it is more popular now than ever. It is a beautiful, hardy, easy-to-breed species that will reward its keeper with much enjoyment in return for simple basic care, and it continues to amaze serious breeders with its propensity to provide ever-new fin and color mutations.