Siamese Fighting Fish (Betta splendens)

Common Name:

Betta (Bet-tuh) (also wrongly pronounced Beta (Bay-tuh), Siamese fighting fish.

Scientific Name:

Betta splendens. This is derived from the local native name Ikan Bettah and the splendens part meaning brilliant.


Belontiidae, a member of the Anabantid group or Labyrinth Fish.


Commonly Thailand and other parts of South East Asia.


Males 6cm (2.5 Inches), Females 5cm (2inches).


Bettas are omnivorous and will accept a wide variety of flakes, worms and critters.

Water Temperature:

Ideally 75-80 degrees F.


Ideally 6.8-7.5. Too much emphasis is places on actual pH, Bettas can adapt to many different pHs. A stable pH (one that remains constant) is far more important.

Life Span:

2-3 years, with well looked after fish reaching 4-5 years.


Bettas can be kept in many different tank set-ups, ranging from solo to a large peaceful community. They must not be kept with fish which like to nip as their full fins and slowness will make them an easy target. Bettas are not good in strong currents, instead preferring to have fairly still water, so in community tanks an area of calm needs to be set aside to make the them more comfortable. I prefer to keep Bettas solo in 10 gallon tanks, but anything larger than 5 gallons can successfully home.


There are several ways to attempt to sex Bettas, some fraught with peril. I will try and explain. Males generally have longer and fuller fins, but some females are bred now with long fins. Generally the male's body is less wide, and more elongated but this is not easy to identify if the fish is young. Males are also generally much more colourful than females but that's not a guarantee either. Males generally flare at each other, but again, I have also had females aggressive enough to flare. So how do you know yours are male and not female? The easiest way is the female possesses an ovipositor tube or egg spot. This is a tiny white spot the size of a grain of salt located on the belly between the anal fins and ventral fins. To make this more confusing it is possible for immature males to have this same spot, although it is not found in mature males, so the chances of finding one on a pet shop Betta are remote.


A word of caution before attempting to breed Bettas, they are not the most difficult fish to get to breed, but they do come close to the top of the list. They are most receptive to breeding between the ages of 6-14 months. Beyond this, the chances are greatly reduced. The female must be smaller than the male to enable the male to wrap himself around her. Male take full responsibility for the eggs once they are laid. He first makes a bubble nest and then encourages the female to breed. He then gathers the eggs up in his mouth and deposits them in his bubble nest. He will then tend the eggs until they hatch. Upon completion of mating it is essential the female be removed from his tank as he may see her as a threat to the eggs and will attack and kill her. Breeding can be damaging to the female, so removal to a quarantine tank to treat any fin damage which may have occured would be prudent If this is a community tank, he may attack any other fish that gets too close to his nest.


Bettas now come in a multitude of different colours and tail shapes. In the wild, these colours would not be a good idea, so wild Bettas are generally greenish browns and greys, with some of the more common colours we see in our Bettas only being seen on the wild fish in small patches. The reasons wild Bettas are not the colours we see are two fold; the colours we commonly see are made through selective breeding of certain colour strains and secondly, if the wild fish were to display these colours they would be as well to wrap some parsley around themselves as garnish to all the predators they would attract. For examples of colours check out this article. Like colours, finnage is also predominantly a man made thing; wild Bettas are genetically short finned with the occasional long finned mutation. This is a mutation which has been exaggerated by selective breeding over the decades till we get the long finned varieties that we commonly think of when we hear the word Betta. We now have several varieties of tails on Bettas ranging from the most common veil tail (pet shop Bettas) through to the more exotic Delta Tails and Crown Tails. For more examples of tail styles and finnage check out this article.


Bettas are very undemanding fish as they require very little in the way of filtration. I mentioned at the beginning they were Anabantid (Labyrinth Fish), which means they possess a labyrinth organ that works, in effect, like a lung, allowing them to breathe air at the surface. They require soft bushy plants, which they use as part of their natural defence strategy to escape predators. They require tanks of at least 5 gallons with lots of surface space, not Betta vases. Like all "TROPICAL" fish they require constant temperature and water parameters. They need a varied diet and also mental stimulation. Since I keep my Bettas alone, I daily use a mirror, this provokes males to flare and can promote confidence. You could also try using a marble on the substrate; I have heard it said that Bettas enjoy rolling them around. I have yet to validate this for myself, but it comes from some very reliable sources.


Males and females are generally very different in behaviour, males will not tolerate other males in their territory, so will flare at each other in an attempt to drive the other off. If this fails, they will fight. This behaviour can be demonstrated above with the mirror I use to promote confidence. The male will spend literally hours flaring at his reflection in the attempt to drive this other male off, and when he finally does (when you remove it) he is the king of his castle once again. I have heard people keeping males with females, and this if fine so long as there are enough hiding places for the females. Personally I have had no luck at all with this and the females spent their whole day striped with fear. Females can form two different stripes on their bodies, horizontal and vertical. Horizontal stripes are stress or fear stripes, these can come and go very quickly and many times a day depending on the female's mood. The less common stripes on female Bettas are vertical, these are breeding stripes and are to display to the male that she is receptive and ready to breed. Both male and female are generally very peaceful but there are obviously exceptions to every rule. I have had females which were so aggressive they would attack anything that swam near. By and large, however, they are the bullied, not the bullies, so care must be taken when selecting tank mates.


Females are easy and compatible with almost all peaceful fish, except male Bettas. Males with males will not work. Likewise, neither will males with females. However females with females will. Males are harder to keep as community fish but not impossible. Males can do well in community tanks with large schools of Danios, Harlequin Rasbora, Corydoras, Cherry Barbs and many varieties of Tetra, although not all. The fish to avoid for the Betta's sake are any fish which displays a tendency to nip fins. Obvious examples would be Tiger Barbs, Serpae Tetra and Redeye Tetra. I mentioned that the males are generally the bullied rather than the bully, but there are some notable exceptions to this rule. Male Bettas take exception to other fish with large billowy tails and fins, so keeping them with Guppies and Fancy Guppies is going to be a painful experience for the Guppy. There also seem to be problems with keeping other members of the Belontiidae family such as the Gourami, which male Bettas have been known to attack.

Tank levels:

Bettas are technically top to middle swimming fish, but my experience suggests they go where they please. They eat most of their food at the surface, but are just as capable of shifting some gravel at the bottom for a treat. They enjoy swimming through plants and caves, so supplying these will be good for keeping them active and amused.

Ease of keeping:

Bettas are very easy to keep. If they are supplied with all the essentials of life, there is little reason that your fish should not live for many years. It is worth pointing out though that pet shop Bettas are not easy to keep. They are bred in large muddy puddles and pumped full of chemicals and growth enhancers. The sad fact of pet shop Bettas are most aren't of a high quality to start with, and most aren't young either. It's a common practice to breed the fish before selling and in some instances several times, so it's possible that the Betta you are buying from large petstores is already 18 months old and past breeding. This should be taken into consideration given that their life expectancy is 2-3 years.

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