Betta splendens- The ultimate tropical fish

The Betta splendens or by its common name Siamese Fighting-Fish is a beautiful hardy tropical fish. This Siamese Fighting-Fish is from the Mekong river basin in Thailand, Vietnam and Cambodia (South-East Asia). Usually lives in shallow waters with little water movement, like Rice-Paddies. In nature, this specie’s males have shorter fins that those we usually see in shops, these are called by the Thai “Plakad” (meaning- “Fighter”), and are used in Thailand for show-fights (just like roosters). Although their fins are short, they are still bigger than those of females. These males are more aggressive than long-finned males, but they are less susceptible to infectious diseases and have faster ability to recover after fights. Of the long-finned strains, there’s the most known Veil-tail, which are the commonest in shops. More appreciated tail forms are the Round-tail, Fantail, and Delta-tail. All these tail forms can appear in two fin forms- Double-tail and Comb/Crown-tail. Double-tail has a long dorsal fin, and their caudal fin is variably divided to two lobes. Comb-tail has fin rays that grow variably longer that the fin’s soft tissue, resembling a comb. Crown-tail is a Comb-tail with equal and symmetric lengths of fin rays and soft tissue. Another famous strain and probably the most famous is the Half-moon. This is a fin form, appearing mostly on Delta-tails, in which the caudal fin is spread to 180o, while flaring. Aside of it, the fish must have other criteria to be considered as a true Half-moon.


Aside from tail forms, these fish come in all colors and patterns. In nature, they have a black body, with turquoise/blue/steel-blue iridescent on it, and red washes on it fins. The first color strain produced was called Cambodian, with clear-pinkish body and red fins. By today, with further understanding the fish’s genetics, we have Solid colored fish, in the colors of Red, Non-red Yellow, Black, White, Orange, Royal-blue, Steel-blue, Turquoise and the newest- Copper. Then comes the Bi-colors, mostly Cambodians and Iridescent with red or yellow washes on their fins. And along side with these, come the Tri-colored, also known as Multi-colored, mainly containing the colors- Clear + Iridescent + Red. Patterns have also developed, from the “solid” regulars, we’ve got to Variegated-fins (the most appreciated is the known Butterfly), and Marbled (which can change their color patterns throughout their life). Every breeder give different names to the strain lines they create, one of these, most known, is the Mustard-Gas created by Jude Als. By looking at all the colors, patterns and tail and fin forms, it is easy to see why this fish is probably one of the most known and popular freshwater fishes. The betta is a carnivore fish in its natural habitat; it eats mainly insect larvae, small crustaceans and other aquatic invertebrates. The fish is mostly accustomed to dry commercial foods, so will have no problem with these foods- make sure it is mainly meaty foods. In out fish tank the fish is mainly calm, and might be shay in community aquariums at start, once settled it will get active. Males and females are aggressive towards each other. In long-finned cultivated strains, females tend to be more aggressive than males. Males will always fight over territory and might kill one another. The betta is durable to low water conditions, though; long-finned strains are more susceptible to high amounts of nitrogen compounds in water and will quickly suffer from fin-rot, dropsy and other illnesses. In large aquariums these fish need good filtration system with low to moderate water flow. If water flow is too strong, the fish will settle in a spot where flow is lowest and will hardly move from it. When kept in a jar, water should be changed every week- the amount of water changed, depends on the jar’s volume. Some people buy dry leafs of a tree called Ketapang/Indian Almond-tree (Terminalia katappa) and insert them to the fish’s jar. It is said to help preventing infectious diseases and getting the fish into breeding-mood. When feeding these fish, avoid over-feeding, as these fish tend to gorge itself, which might end up in a bloated fish suffering from deadly incurable Enlarged-leaver.


This Betta species is a Bubble-nest builder. There are many ways to set up a breeding aquarium for the pair, and not enough room to supply details on them all. There are two popular ways to breed the Siamese Fighting-fish- in an aquarium specially set for the pair, which should be at a volume of at least 20 liters (5.2 gallons), and the Thai-way, which uses large Plant-pots. In any of these ways, the fish must be conditioned well before introducing the pair. Conditioning is made by feeding the fish live or frozen foods about two to three times a day, and making frequent water changes. Conditioning should take about two weeks at least, and can take up to one month, depending on the food quality and water temperature. The breeding set-up, in both ways, should contain lots of hiding places for the female, and some floating plants for the male to build its nest. If floating plants aren’t available, you can use a halved Styrofoam-cup. Water temperature at the breeding set-up should be in the range of 28-30oC (82.4-86oF/ 301-303oK), and it is advisable to place a tight fitting glass-cover on top, so that the air above water will be hot and humid. Using an aquarium, the female is usually placed in a clear chamber, so that the male can see her, but can’t touch her. Once the male has built his bubble-nest, he will start courting the female. For those of you, who placed the female in a chamber, release her only after she presents the following signs- swimming with and toward the male (instead of trying to escape), showing white vertical bars on her body (instead of two black lateral lines, which display fear), pacing her head down and swimming towards the male by moving her body from side to side. The last sign usually appears after the female is released, so seeing it isn’t obligatory before introducing the pair. Mostly, after the female is released, the male will attack her- do not panic, these fish like it rough, and this is why hiding places are very important. Once the male and female are ready to spawn, the female will follow the male under the nest, where he will wrap her with his body. These first embraces are usually called Test-embraces, and are used to confirm that there is a match between the male and female.


After several embraces, the male will freeze in the embraces, and the pair will stay still for a couple of seconds. Afterwards, the male will swim down to collect the eggs, while the female usually remains frozen and floats to the surface. Some females will collect the eggs after “awaking” and will place the m in the nest, others simply eat them. Once the male collects the eggs, he will coat them with saliva, and places them inside the nest. After mating is complete, the male usually attacks the female and chases her away; this is a good time to remove her from the breeding set-up. The male will tend the eggs, and the larvae that will hatch within the next 24-36 hours, picking up any egg and fry that will fall from the nest and placing them back in it. After about 48 more hours, the fry start swimming freely, at this point, remove the male as well. Once the male is out, it’s time to insert an air-operated sponge-filter (the filter must run for about two weeks before spawning in a well established aquarium!!!) and to feed the fry. First foods which are suitable for fry as small as these, are Infusorians (mostly Paramecium), Green-water, Powdered dry foods and liquid fry foods. Another way to supplement the fry’s diet is by using Java-moss (Taxiphyllum barbieri) in the aquarium (this plant is also essential as a hideout for the female!)- This plant provides a substrate for a rich Micro-fauna of microscopic creatures, which supply addition to the fry’s diet. The fry should be fed about two to three times a day, be careful not to over feed them, as ammonia is the second fry killer (first is hunger). Once the fry are about a week old, you can start adding Micro-worms to their diet, and after another week adding BBS (baby brine-shrimps). Make sure you change the water frequently, using a gentle siphon. Siphon the bottom to take out any uneaten foods, and turn the hose to a bucket; so that any fry siphoned, will be found and returned to the aquarium. It is important to return the fry to the aquarium before adding the new water in. Adding the water should be done gently, you may use an air-hose to do that. Mostly in about 1.5 cm (0.59 inches) of size, you will be able to tell the males apart; their ventral fins will look pointier and larger, and they are mostly more aggressive. The fish usually reach sexual maturity in an age of about 3 months, and then can be moved to their new owners.

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Rotem Gavish is a fish expert. Dedicating his life to this beautiful hobby, his expertise is in all related to aquarium world such as tropical fish, fish tank, marine fish, plants and invertebrates. Rotem established his site with the vision of sharing tips and free information.

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