Siamese Fighting Fish Fact Sheet

There are several species in the genus Betta, but the best known and most spectacular is the Siamese Fighting Fish; Betta splendens; the splendid Betta. This fish comes from Thailand and the old name of Thailand was Siam. Other names for this fish are: Japanese Fighting Fish, Samarai Fighting Fish, Chinese Fighting Fish and Mexican fighting Fish. The Cambodian Fighting Fish is a colour variety of this fish. If you put two males together they will usually fight after going through a display. The display seems to be part of the fish's method of recognising the sex of the other fish. In a limited space like a small aquarium a fight would usually end with one fish dead. In Thailand fish fights are staged with betting on the outcome. This is a traditional sport which is now illegal in Thailand, although this does not mean that it never occurs.

Females can be put together with each other and one male in a reasonable sized aquarium. Usually there is no serious trouble between them although a tank some hiding places is a good idea.

The males are usually much more spectacular than the females, having longer fins and more intense colour.


Fighting fish are a tropical fish; 24 degrees C is a suitable temperature. They can take at least 10 degrees higher than this, but will not be comfortable any lower than about 18 degrees C. In a climate like that of South Australia they need heating in the winter. The usual way of heating the tank is with an aquarium heater. A 50w heater is suitable for a small Aquarium. If you have a room that never gets cold then the Fighting Fish can be kept there without an aquarium heater. A room that is only heated by the sun will get cold when the sun is not shining. This is not suitable.

Some very small tanks are sold for fighting fish. These are suitable for places with a warm climate. In temperate areas they are not suitable for fighting fish in winter unless they can be kept in a place which does not get cold. Many of these tanks are too small to put a normal aquarium heater in.


Fighting fish are anabantids. They and their relatives can breathe air as well as water. This means that they can live in much smaller aquariums than most fish. In the wild they sometimes live and even breed in very small bodies of water including the water filled hoof prints of a water buffalo. They are often also found in rice fields. They need to be able to get to the surface or they can drown. Although they can be kept in very small containers this is not an ideal way. Like other fish they are affected by water quality. A small tank is harder to keep clean than a larger one, and usually you cannot put a filter in.


The Fighting fish is sometimes described as a carnivore. In my observation, it is an omnivore with a preference for animal based food. In an aquarium, I recommend that a good quality Betta food be used as the basic diet, and this should be varied with the addition of the occasional feeding of live food like mosquito larvae of daphnia. frozen food like blood worms are also good.



Rainwater is often used. Some people use it successfully, but not all rainwater is safe for fish. Rain, as it falls from the sky in Rural areas is generally good water. When it comes into contact with the roof and gutters and then stays in the rainwater tank with any leaves etc which have washed in, it picks up contaminants. Some of these are harmless, but others can kill fish. If rainwater is the only type of water available then you will need to use it. Apart from the obvious things like keeping your gutters clear and avoiding spraying near the house or if the wind is towards the house you can add a rainwater conditioner. This will add the salts that rainwater does not have. It will also neutralise some (but not all) of the possible contaminants.

Mains Water

If you are in an area with Chlorinated water, a water conditioner will get rid of the Chlorine. In areras which use Chloramine, ther conditioner will still work, but needs to be used at up to five times the normal rate.

If the Ph of the water is adjusted to be less than 7.2 the ammonia from the Chloramine should not be dangerous.

There are also some water conditioners which remove ammonia as well as Chlorine. I recommend the use of one of these.

Filtered Tapwater

Some domestic water filters which have carbon cartridges will remove most of the Chlorine and Chloramine. The filter cartridge needs to be in good condition. If you have a filter it is a good idea to use this water for your fish. However, because the filter may not remove all the Chlorine or Chloramine from the water, it is still a good idea to use a conditioner to be on the safe side.

Spring Water

Many types of spring water are suitable for fighting fish without any conditioner or modification. If it is too far from neutral you will need to adjust it.


Ph is a measure of acidity or alkalinity. A ph of 7 is neutral. Below 7 is acid and above 7 is alkaline. The ideal Ph for fighters is about 7.1, but they can take moderate variations from this. The Ph of water can change, so it is a good idea to check it regularly.

Foods and feeding

Like most fish, fighting fish are omnivores, in the wild they will eat any animal or vegetable food they can find. They prefer animal foods such as mosquito larvae (wrigglers) daphnia, etc. In an aquarium they will eat all normal types of aquarium foods, but seem to do better on a food designed for them. As with almost any animal a variety of food is welcomed by fighting fish. Do not overfeed!

Aquariums and Companions

One fighting fish without any other fish can be kept in a quite small tank, provided that it can be kept warm. Fighting fish are usually not an aggressive fish and can be kept in an aquarium with other peaceful fish of a similar size or smaller.

These are a few of the many sorts of fish suitable as companions for fighting fish in a reasonable sized aquarium.

Like nearly all fish, fighting fish will eat another fish if the fish is small enough to fit in its mouth. Generally a fighting fish can be kept with fish as small as neon tetras without trouble. However, the occasional fighting fish may learn to catch neons. I would suggest that in a confined space fighting fish should be by themselve. I know of at least two cases of a fighting fish which has been put in a bag with neons and has learned to eat them. Having learned, the fish is likely to continue to eat neons in an aquarium. Fish have quite good memories.

Fighting fish are slow and have long fins. They are very vulnerable to fish that nip fins.

Some of the fish that can be fin nippers and which I would not recommend as companions for fighting fish are Tiger Barbs, Red Eye Tetras, Serpae Tetras, Some Galaxies and Rosy Barbs.

Another way of keeping fighting fish is to use one of the Betta containers. These come under several names, but are similar and allow several male fighters to be kept in one aquarium.

Another, similar, way of keeping fighters is to use a breeding tank which floats in an aquarium. Normally these are use for breeding fish such as Guppies, but they can also be used for keeping (but not breeding) Fighting Fish.

There are several other options for keeping fighting fish. There are Duo and a Trio Fighting Fish tank, as well as many types of custom ones. The better ones are big enough to put a small heater into one of the compartments. There is often enough conduction of heat between compartments to keep them all warm enough.

Transporting fighting fish

Normally fighters are transported in a plastic bag. It is important that there be some air (or Oxygen) above the water in the bag. The bag should not be allowed to get very cold or very hot in transport. It is better that if you are transporting a male fighter that no other fish is in with it.

Life Span

Siamese Fighting Fish are not very long lived. Their normal life span is about two years. The Male fighters normally on sale in shops are typically about nine months old, so if you have had a male fighter for a year, it is already old and could die of old age.