All Betta species are small fishes, but they vary considerably in size, ranging from under 2.5 cm (1 in) total length in B. chanoides to 14 cm (5.5 in) in the Akar betta (B. akarensis).[1]
Bettas are anabantoids, which means they can breathe atmospheric air using a unique organ called the labyrinth. This accounts for their ability to thrive in low-oxygen water conditions that would kill most other fish, such as rice paddies, slow-moving streams, drainage ditches, and large puddles.[2]
The bettas exhibit two kinds of spawning behaviour: some build bubble nests, such as B. splendens, while others are mouthbrooders, such as B. picta. The mouthbrooding species are sometimes called "pseudo bettas", and are sometimes speculated to have evolved from the nest-builders in an adaptation to their fast-moving stream habitats.[3]
A phylogenetic study published in 2004 concluded tentatively that bubble-nesting was the ancestral condition in Betta, and that mouthbrooding has evolved on more than one occasion in the history of the genus. However, it was unable to establish a correlation with any of three habitat variables studied: whether a species was found in lowland or highland streams, whether it was found in peatswampforests, and whether it was found in water with fast or slow currents.[4] Mouthbrooding species tend to exhibit less sexual dimorphism, perhaps because they do not need to defend a territory as the bubble-nesters do.[4]
Name
Siamese fighting fish (B. splendens) are frequently sold in the United States simply as "bettas". As of 2017[update], around 73 species are classified within the genus Betta.[1] A useful distinction is that, while the generic name Betta is italicized and capitalized, when used as a common name it is usually neither italicized nor capitalized.[5]
The common nameofB. pugnax, for example, is thus Penang betta.
Betta splendens, the Siamese fighting fish, is often referred to simply as a "betta" in the U.S.
The name Betta (or betta) is pronounced /ˈbɛtə/;[5] the first part is the same as the English word bet. The name is often pronounced /ˈbeɪtə/inAmerican English, and may be spelled with one 't'. The name of the genus is derived from the Malay term ikan betah ("persistent fish").[6]
The vernacular name "plakat", often applied to the short-finned ornamental strains, derived from pla kad which means "fighting fish", is the Thai name for all members of the B. splendens species complex (All have aggressive tendencies in the wild and all are extensively line-bred for aggression in eastern Thailand). The Thai phrase is not restricted to one specific strain. The term "fighting fish" is generalized to all members of the B. splendens species complex, including the Siamese fighting fish.[7][8]
Diet
Wild Betta fish are hardy and eat almost any animal small enough to consume. This includes worms, larvae of mosquitoes or other insects, and smaller fish. Their natural environment is often resource-limited, so many Betta species are generalist feeders.
Bettas as pets
Bettas are commonly kept as pet fish, especially Siamese fighting fish. Bettas are popular fish due to their color variety and ease to care for, although the males must be kept separated from other bettas.[9]
Conservation
While many Betta species are common and B. splendens is ubiquitous in the aquarium trade, other bettas are threatened. The IUCN Red List classifies several Betta species as Vulnerable. In addition, B. livida is Endangered, and B. miniopinna,B. persephone, and B. spilotogena are Critically Endangered.[10]
^ abRüber, Lukas; Britz, Ralf; Tan, Heok Hui; Ng, Peter K. L.; Zardoya, Rafael (April 2004). "Evolution of Mouthbrooding and Life-History Correlates in the Fighting Fish Genus Betta". Evolution. 53 (4). Society for the Study of Evolution: 799–813. doi:10.1554/03-364. JSTOR3449277. S2CID198158291.
^Tan, H.H.; Ng, P.K.L. (2005). "The fighting fishes (Teleostei: Osphronemidae: genus Betta) of Singapore, Malaysia and Brunei". Raffles Bulletin of Zoology. 13: 43–99.
^Tan Heok Hui (2023). "A new species of black water fighting fish from Singkep Island (Teleostei: Osphronemidae)". The Raffles Bulletin of Zoology. 71: 491–495.
^Tan Heok Hui (2009). "Betta pardalotos, a new species of fighting fish (Teleostei: Osphronemidae) from Sumatra, Indonesia". The Raffles Bulletin of Zoology. 57 (2): 501–504.
