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Siamese fighting fish

Betta splendens

Photo: Siamese fighting fish
Weights and measures
Length from 6 to 7 cm
Animal description
The Siamese fighting fish, scientifically known as Betta splendens, is a captivating and popular freshwater fish native to the Mekong basin of Thailand, Cambodia, Laos, and Vietnam. They are part of the gourami family and are known for their vibrant colors, elaborate finnage, and unique behavioral characteristics.

Siamese fighting fish typically measure up to 2.5 inches (6.5 cm) in length in the wild, but captive specimens can grow slightly larger. One of the most striking features of the Betta splendens is their brilliant coloration, which can range from deep blues and reds to purples, oranges, and a variety of pastel hues. Selective breeding has further enhanced these colors, along with the development of different patterns such as marbling and butterfly wing-like finnage.

The males of the species are particularly noted for their extended and flowing fins, which can include the dorsal (top), caudal (tail), pectoral (side), anal (bottom), and ventral (front bottom) fins. These fins can be so elongated and ornate that they resemble the gowns of courtiers from a bygone era, fluttering gracefully with every movement. Females, on the other hand, are generally less colorful and have shorter fins, but they still possess a subtle beauty of their own.

A defining characteristic of the Siamese fighting fish is its labyrinth organ, a unique adaptation that allows it to breathe atmospheric oxygen directly. This is an evolutionary response to the low-oxygen environments in which they are often found, such as rice paddies, stagnant ponds, and slow-moving streams. As a result, Bettas can survive in water conditions that would be lethal to other fish species.

Behaviorally, the Siamese fighting fish is best known for its territorial and aggressive nature, especially among males. When two males encounter each other, they will flare their gills, spread their fins, and display their most intense colors in an attempt to intimidate the opponent. These displays can escalate to physical skirmishes, which is why the species has the moniker "fighting fish." In the wild, these confrontations rarely lead to serious injury, as the weaker fish can retreat. However, in captivity, care must be taken to house males separately to prevent harm.

Mating behavior in Betta splendens is also fascinating. The male builds a bubble nest at the water's surface, which can be quite elaborate, using his mouth to create and maintain the structure. When a female is ready to spawn, the male entices her to the nest, where he wraps his body around hers in a nuptial embrace, squeezing the eggs out for him to fertilize. He then collects the eggs in his mouth and places them in the bubble nest. The male takes on the role of protector, guarding the nest and keeping the eggs oxygenated until they hatch.

In the aquarium trade, Siamese fighting fish are favored for their ease of care and minimal space requirements. They can thrive in small tanks or bowls with regular water changes and appropriate temperature maintenance. A diet of high-quality pellets, flakes, and occasional live or frozen foods like brine shrimp or bloodworms will keep them in good health.

Their popularity has led to a multitude of captive-bred varieties, with enthusiasts and breeders continually working to develop new strains with even more striking colors and fin shapes. However, this popularity has also led to concerns about overbreeding and the welfare of these fish, as they are often kept in inadequate conditions due to misconceptions about their needs.

In summary, the Siamese fighting fish is a species with a rich history and an array of qualities that fascinate both aquarists and biologists alike. From their breathtaking appearance to their complex behaviors, Betta splendens continues to captivate the hearts of those who encounter them, embodying both the beauty and the intrigue of the natural world.
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