The fish most commonly known as Betas are a species of the genus Betta called Betta splendens. Like other Betas, these fish can survive in very small bodies of fresh water, thanks to a special organ called the labyrinth. Because of this organ, which allows them to breathe atmospheric air, they are able to thrive in low oxygen water, including puddles, ditches, slow streams and rice paddies. Betas are about two to two and a half inches long and live, on average, for about four years. Some specimens have lived up to a decade in laboratory settings.
Historically, Betas have been used in some Asian countries for a sport rather like cockfighting. Because of this, they are also known as Siamese fighting fish. The specimens used for this sport were bred to be short-finned and very aggressive. Modern Betas are more likely to be showy, decorative animals. Originally, only the males of the species showed the bright colors that are synonymous with Betas, but recent strains have produced bright, showy females as well.
Female Betas are the same general size and conformation as males, but have shorter fins. In males, the pelvic fins in particular are very long and extended. Specialized types of male Betas with particularly unusual tails have been bred, including the crowntail, double tail, and halfmoon tail Betas. As male Betas age, the tail becomes larger, longer, and heavier. Eventually, this causes the fish to become sluggish, and it will eventually lose the tail. It will grow back, but not look exactly the same, and the loss of the tail rejuvenates the fish.
Betta fish are carnivores. Their mouths are full of rows of tiny pointed teeth. Despite the sharpness of these teeth, the males routinely carry eggs in their mouths without causing any damage. In captivity, they eat homogenized Betta pellets or blood worms and brine shrimp. Many aquarium-bred fish will also accept flaked tropical fish food.
Male Betas raise their babies. They build bubble nests for this purpose, and will even do so if there are not females or babies around. They do this by manipulating bubbles of air with their mouths into nests of various sizes and thicknesses at the top of the water. Many Betas prefer some sort of shelter, such as vegetation, for their bubble nests.
The lower half of the Beta’s anatomy is mostly swim bladder, flesh and bone. The internal organs are located between the head and the beginning of the anal fin. This fin is the large fin on the lower half of the fish’s body, in front of the tail. The other fins are called the dorsal, pectoral, and pelvic fins. Betas also have gill covers, which they may flap open in response to a perceived threat. Male Betta fish are famous for their displays when confronted with other males. They open their brightly colored fins and flap the gill covers in an attempt to look larger than they actually are.
