Betta splendens family
Betta splendens Regan, 1910, Menam River [= Mae Nam Chao Phraya], Thailand.
other common names
English: Betta; French: Combatant, combattant du Siam; German: Siamesischer Kampffisch; Spanish: Combatiente siamés.
Up to 2.4 in (6 cm). Elongate cylindrical body, dorsal fin short with one to two spines and seven to 10 soft rays. Anal fin is long with two to five spines and 21-26 soft rays, caudal fin rounded. First soft ray of pelvic fin elongated. Sexually dimorphic; males have larger fins and a brighter coloration, females less conspicuously colored. Wild type with bluish body and blue and red fins. Two vertical iridescent marks on the opercle. Some breeds with greatly enlarged fins (sail fin) and different colors or combinations thereof, some almost completely red, blue, yellow, or black.
The original distributional range comprises the Chao Phraya basin in Thailand and northernmost Malay Peninsula (north of Isthmus of Kra). The species has been transported and released in various countries in Southeast Asia, and can now be found even in the Dominican Republic, Colombia, Brazil, and Florida, in the United States.
Tolerates a wide range of water parameters. Common in stagnant or standing water bodies with dense aquatic vegetation, especially in rice paddies and in canals. May dig into the mud when the water recedes and survive weeks in a small cocoonlike structure made of mud and probably mucus.
This species is well known for its prominently developed aggressive behavior, especially against conspecific males. Confined to small tanks, males fight until one of them is killed. In Thailand, various breeds of Betta splendens are used in popular fighting matches in which people bet on the outcome.
feeding ecology and diet
Carnivorous, feeding mostly on small aquatic invertebrates, such as zooplankton and insect larvae.
The male constructs a bubble nest and aggressively defends the territory around it. Has typical spawning clasp. After the spawning claps, male and female show spawning rigor, from which the male recovers earlier (after 4 s) than the female (after about 20 s). Up to 400 spherical eggs with a diameter of 0.04 in-0.05 in (1-1.4 mm) are laid per spawning sequence. They contain no oil globule and sink toward the bottom. While eggs are sinking they are collected by the male, later joined by the female, and stored in the nest. Hatching takes place after 32 to 35 hours at 84.2°F (29°C). Larvae swim free on the fourth day.
Not listed by the IUCN.
significance to humans
Very popular aquarium fish. Because of its hardy nature, often among the first species of freshwater fishes kept by beginners to the aquarium hobby. Of no interest to fisheries due to its small size. ♦
Mouth brooder with male parental care. Male defends territory around spawning site. Displays conspicuous sexually dichromatic coloration only during courtship and spawning. Mating with a reduced spawning clasp takes place at the bottom. All eggs are released during a single spawning bout, sink to the bottom, and are taken up into the male's mouth. The male mouth broods up to 150 eggs with a diameter of around 0.12 in (3 mm) for about four weeks. Eggs are pear-shaped, with a striking pattern of parallel surface ridges leading toward the micropyle (a preformed opening, the only place where sperm can enter the egg), where the ridges end in a counterclockwise spiral. This unique surface pattern also occurs in the genera Parasphaerichthys, Ctenops, and Sphaerichthys, demonstrating the close relationship of the four groups. Egg surface pattern may represent a sperm guiding device to enhance fertilization success. Upon release from the male's mouth, young pike-heads already measure 0.6 in (1.5 cm) long.
The species is not threatened or endangered, but may suffer in the future from habitat destruction.
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