Siamese fighting fish
The Siamese fighting fish, commonly known as the Siamese fighter, or locally as the betta, is a freshwater fish native to Southeast Asia, namely Cambodia, Laos, Myanmar, Malaysia, Thailand, and Vietnam. It is one of 76 species of the genus Betta, but the only one eponymously called "betta", owing to its global popularity as a pet; Betta splendens are among the most popular aquarium fish in the world, due to their diverse and colorful morphology and relatively low maintenance.
Betta fish are endemic to the central plain of Thailand, where they were first domesticated at least 1,000 years ago, among the earliest of any fish. They were initially bred for aggression and subject to gambling matches akin to cockfighting. Bettas became known outside Thailand through King Rama III, who is said to have given some to Theodore Cantor, a Danish physician, zoologist, and botanist. They first appeared in the West in the late 19th century, and within decades became popular as ornamental fish. B. splendenss long history of selective breeding has produced a wide variety of coloration and finnage, earning it the moniker "designer fish of the aquatic world".
Bettas are well known for being highly territorial, with males prone to attacking each other whenever housed in the same tank; without a means of escape, this will usually result in the death of one or both fish. Female bettas can also become territorial towards one another in confined spaces. Bettas are exceptionally tolerant of low oxygen levels and poor water quality, owing to their special labyrinth organ, a characteristic unique to the suborder Anabantoidei that allows for the intake of surface air.
In addition to its worldwide popularity, the Siamese fighting fish is the national aquatic animal of Thailand, which remains the primary breeder and exporter of bettas for the global aquarium market. Despite their abundance as pets, in the wild, B. splendens is listed as "vulnerable" by the IUCN, due to increasing pollution and habitat destruction. Efforts are being made to support betta fish breeders in Thailand as a result of their popularity as pets, cultural significance, and need for conservation.
Etymology
Outside Southeast Asia, the name "betta" is used specifically to describe B. splendens, despite the term scientifically applying to the entire genus, which includes B. splendens and at least 72 other species. Betta splendens is more accurately called by its scientific name or "Siamese fighting fish" to avoid confusion with the other members of the genus.English-speakers often pronounce betta as "bay-tuh", after the second letter in the Greek alphabet. However, it is believed the name is derived from the Malay word ikan betta, with ikan meaning "fish" and bettah referring to an ancient warrior tribe, which is pronounced "bet-tah". Alternative sources suggests the name Betta splendens is formed from two languages, consisting of Malay for "enduring fish" and the Latin word for shining.
Another vernacular name for Siamese fighting fish is plakat, often applied to the short-finned ornamental strains, which is derived from the Thai word pla kat, which literally means "biting fish". This name is used in Thailand for all members of the Betta genus, which share similar aggressive tendencies, rather than for any specific strain of the Siamese fighting fish. Thus, the term "fighting fish" is used to generalise all Betta species besides the Siamese fighting fish.
Siamese fighting fish were originally given the scientific name Macropodus pugnax in 1849—literally "aggressive fish with big feet", likely in reference to their elongated pelvic fins. In 1897 they were identified with the genus Betta and became known as Betta pugnax, referring to their aggressiveness. In 1909, the species was finally renamed Betta splendens upon the discovery that an existing species was already named pugnax.
Description
B. splendens usually grows to a length of about. Although aquarium specimens are widely known for their brilliant colours and large, flowing fins, the natural coloration of B. splendens is generally green, brown and grey, while the fins are little short; wild fish exhibit strong colours only when agitated. In captivity, Siamese fighting fish have been selectively bred to display a vibrant array of colours and tail types.The variety of colors we see now in pet stores is a result of the domestication of the Betta splendens. Because pet stores are more likely to sell the visually striking bettas, those are the types of bettas the breeders continue to prioritize. The more natural colored bettas like green, brown, and grey may rarely be seen now in pet stores due to the overshadowing of the more visually appealing colors.Male and female Betta splendens can look similar, but one way to distinguish between the two is to identify the ovipositor tube that's located in females used for egg delivery.
Distribution and habitat
According to Witte and Schmidt, Betta splendens is native to Southeast Asia, including the northern Malay Peninsula, central and eastern Thailand, Kampuchea, and southern Vietnam. According to Vidthayanon, a Thai ichthyologist and senior researcher of biodiversity at WWF Thailand, the species is endemic to Thailand, from the Mae Khlong to Chao Phraya basins, the eastern slope of the Cardamom mountains, and from the Isthmus of Kra. Similarly, a report from Froese and Pauly identifies Betta splendens as native to Cambodia, Laos, Thailand, and Vietnam. They are also found throughout the neighbouring Malay Peninsula and in adjacent parts of Sumatra, likely due to human introduction.Wherever they are found, Betta splendens generally inhabit shallow bodies of water with abundant vegetation, including marshes, floodplains, and paddy fields. The historic prevalence of rice farming across Southeast Asia, which provided an ideal habitat for bettas, led to their discovery and subsequent domestication by humans. The combination of shallow water and high air temperature causes gases to rapidly evaporate, leading to a significant deficit of oxygen in the betta's natural habitat. This environment likely led to the evolution of the lung-like labyrinth organ, which allows Siamese fighting fish—like all members of the suborder Anabantoidei—to breathe directly from the air. Subsequently, bettas can live and even thrive in harsher environments than other freshwater fish, which in turn leaves them with fewer natural predators and competitors. In the wild, bettas thrive at a fairly low population density of 1.7 individuals per square meter.
The tropical climate of the betta's natural habitat is characterized by sudden and extreme fluctuations in water availability, chemistry, and temperature. Water pH can range from slightly acidic to highly alkaline, while air temperatures drop as low as 15 °C and rise as high as 40 °C. Consequently, Siamese fighting fish are highly adaptable and durable, able to tolerate a variety of harsh or toxic environments; this accounts for their popularity as pets, as well as their ability to successfully colonize bodies of water all over the world.
Wild bettas prefer to live in bodies of water teeming with aquatic vegetation and surface foliage, such as fallen leaves and water lilies. The abundance of plants provides security from predators and a buffer between aggressive males, who coexist by claiming dense sections of plants as territory. Such vegetation also offers protection to females during spawning and to fry during their earliest and most vulnerable stages.
Invasive species
The betta's worldwide popularity has led to its release and home in similarly tropical areas, including southeast Australia, Brazil, Colombia, the Dominican Republic, the southeast United States, and Singapore.In January 2014, a large population of bettas was discovered in the Adelaide River Floodplain in the Northern Territory, Australia. As an invasive species, they pose a threat to native fish, frogs, and other wetland wildlife. Bettas have also become established in subtropical areas of the United States, namely southern Texas and Florida, although an assessment by the U.S. Fish and Wildlife Service noted that while the climate match for this species within the United States is low, no studies have been done to assess the effect of this species upon the invaded range.
Conservation status
Due to their popularity, Siamese fighting fish are highly abundant in captivity. In the wild, betta habitats are threatened by chemical and agricultural run off, in addition to the contamination of human medication residue into aquatic ecosystems from the sewage system. Such contamination can also alter the reproductive behavior of the species by decreasing hatch rate and increasing the likelihood of fathers eating their own eggs. Due to the expansion of palm oil plantation in Southeast Asia, wild bettas are also facing habitat loss. The primary threats are habitat destruction and pollution, caused by urban and agricultural development across central Thailand. Wild specimens are categorized by the IUCN as vulnerable, indicating the species is likely to become endangered without conservation efforts.Diet
Betta splendens is naturally carnivorous, feeding on zooplankton, small crustaceans, and the larvae of aquatic insects such as mosquitoes, as well as insects that have fallen into the water and algae. Contrary to some marketing materials in the pet trade, bettas cannot subsist solely on vegetation or the roots of plants.Although Betta splendens is carnivorous, there are factors that affect juvenile health, such as limited ability for carbohydrate digestion. This can occur in young Betta splendens because their intestines are a lot shorter and their carbohydrate digestive enzymes are not as active as adult bettas. Bettas can also adhere to a diet including rotifers, infusorians, and water fleas, but some of these organisms are derived from avian and porcine farms that can cause diseases, potentially harming the bettas. Even though carbohydrates from a carnivorous diet are essential for maturation in bettas, research on betta health has provided alternatives for food other than their typical diet. Some of these alternatives include microwave cooking, digestive enzyme supplementation, and probiotics, some of which may be found in betta fish food in pet stores.