In aquaristics, fighting fish are popular mainly because of their exotic colors and because of their comparatively modest demands on keeping. This makes them very suitable even for beginners. In some circles they are bred with a lot of passion and know-how, others simply enjoy the colorful variety. However, they owe their designation as fighting fish to their aggressiveness towards conspecifics and other aquarium inhabitants, which should not be underestimated. When choosing the right Bettas – as they are also called – there are a few tips to keep in mind.
Fighting fish at a glance
Many a myth surrounds the fighting fish. Because of their sometimes extremely aggressive behavior, they are used in Thailand, for example, for fish fights and betting. However, those who are just starting out in aquaristics in this country may be put off by such scenarios. The fish are completely peaceful when kept in a species-appropriate manner.
Her scientific name Betta then sounds a lot more trustworthy. They are native to the rice-growing regions of Southeast Asia and can survive in these waters, some of which are extremely low in oxygen, because they have what is known as a labyrinth organ. These are gill cavities located in the skull behind the ear labyrinth. The cavities are so expanded and supported that they do not collapse like the gill laminae. This allows them to hold a volume of air almost equal to that of the swim bladder. Betta fish also use atmospheric air to breathe. In other words, they swim to the surface of the water and gasp for air there. The oxygen content in the water is therefore less essential for them than for other fish species. But the free access to the water surface.
Their way of life has made the exotic fighting fish relatively robust and, above all, easy to care for. On the other hand, they have extremely strong territorial behavior. If they can live this out in the wild and without a shortage of food, the fish remain quite relaxed. In the aquarium, however, there are only limited opportunities for retreat or alternatives.
And so bettas primarily choose combat to resolve conflicts. The combination with other underwater inhabitants is therefore always somewhat problematic. The fish are also not always compatible with each other. Especially the males with their courtship behavior and the urge to defend their territory are very offensive.
On the other hand, they are also the ones that look so intensely colourful. Bettas can come in a wide variety of colors and patterns. Some species are particularly vividly colored, while others also form iridescent shiny scales. The long fins sway in the current and fan out wonderfully when swimming. The females usually remain more subtly colored. Since the coloring of the young fish generally has to develop first, females and males can hardly be distinguished from one another in the first weeks or months of life.
Basically, all fighting fish are small freshwater fish. The largest subspecies is a maximum of 160 mm long. A total of 13 groups of forms are classified:
In addition, the individual Betta species differ in terms of the type of brood care they practice, whether in a foam nest or as mouthbrooders. Additional categories such as caudal fin shapes are largely the result of relevant breeding:
- Crown tail
- long tail
- round tail
- delta fins
- double tail
In terms of diversity, the fighting fish have a large portfolio to offer. And yet they are still considered a rarity in many pet shops. Especially beginners who want to set up their first aquarium are often unsure whether a fighting fish is really suitable, and if so, which one.
The white-fringed dwarf fighting fish (Betta albimarginata)
The white-seam dwarf fish is particularly rare to find in the trade. It originally comes from Borneo and is one of the mouthbrooders. However, since it does not bring the outstanding color splendour, but is usually more salmon-colored, brown or dark red, it is often misjudged at first glance. In addition, it is one of the smaller fighting fish and only reaches 4 to 6 cm.
A special feature are the fins of the males. These have a white outline that is immediately followed by a black one.
The water quality should be specified for the white-margined pygmy fish depending on the origin and as a result can vary from 20°C to 30°C, with a PH value between 5.5 to 7.0 being required. Since you have to pay close attention to where the fish come from, keeping them is not necessarily recommended for beginners. On the other hand, the Betta albimarginata are quite peaceful, at least as long as the tank size offers enough space. However, the aquarium should be well covered: white-fringed dwarf fish are good jumpers.
The Wine Red Fighting Fish (Betta coccina)
As its name suggests, the burgundy fighting fish is burgundy in colour, with the intensity ranging from dull to strong, depending on the mood. The dorsal and caudal fins also have a narrow, white border and – again depending on the mood – isolated metallic-green shiny spots. In the middle of the flanks there are often greenish or turquoise shiny areas. And the Betta coccina, which are about 5 to 7 cm long, shimmer in numerous nuances.
The natural occurrence is limited to the Malay Peninsula and Sumatra. There the fish live in flood zones and swamp areas, mostly in small or residual water bodies. With pH values well below 5, this is not exactly a livable environment. In addition, the spreading agriculture in the regions endangers the populations of bettas immensely.
Therefore, the maroon fighting fish is probably best kept in the aquarium. But here, too, it needs extremely acidic and soft water, which should be clear, clean and sterile. Temperatures between 23 and 27 °C and pH values of around 5 to a maximum of 6.5 are ideal. In short, the maroon betta needs a blackwater aquarium, preferably additionally filtered with peat.
And since these fish also like to jump over the edge of the tank, the aquarium should be well covered. At the same time, the air above the water surface remains correspondingly warm. Otherwise, the animals will catch cold very quickly.
The Peaceful Fighting Fish (Betta imbellis)
The peaceful fighting fish owes its paradoxical name to the moderate territorial behavior that it mainly only develops during the spawning season. In a harem with 4 to 5 females and one male, the animals are optimally utilized, so that other, quiet aquarium inhabitants have nothing to fear.
At 4 to 5 cm, the Betta imbellis is one of the smaller representatives of its kind. In terms of colour, it comes in a spectrum of blue, green and turquoise, with two darker longitudinal stripes on each side of the body in both sexes. In the right mood, the scales even shimmer an intense metallic blue and the fins with a red border.
Coloring and physique differ depending on their origin. The species is native to a wide area in Southeast Asia, both in standing and in calm areas of flowing water. In domestic pet shops, peaceful fighting fish are still relatively rare. Enriching the aquarium with peat is also recommended for these fish. A water temperature of 24 to 28 °C with a neutral pH of 6 to 7 is also sufficient.
The Emerald Fighting Fish (Betta smaragdina)
Here, too, the name says it all: The emerald fighting fish shimmers in emerald-green shiny scales, with nuances ranging from brown to red. When they are ready to spawn, the females form beige-white transverse bands and the fright coloration of the fish is also characterized by a light beige.
In general, the Betta smaragdina, which can be up to 7 cm long, are very skittish, shy and rather calm. They also react sensitively to excessive organic loads in the water. However, beyond that, they are quite modest. Tropical 24 to 27 °C and pH values between 6 and 8 are sufficient for the fish. They originally come from northern and eastern Thailand and are considered to be far less aggressive than their peers.
Siamese fighting fish (Betta splendens)
The best known of the fighting fish is the Betta splendens. Known for its aggressiveness towards other fish, for its display in competitions – and for its magnificent colors in combination with the flag-like fins. For the natives of Thailand and Cambodia, strains of Siamese fighting fish are something of a status symbol. The fish are very popular with us because of their exotic appearance and their impressive behavior, even without having to fight to the death. The local aquarists have really taken the Siamese fighting fish to their hearts.
In wild forms, the males are usually red-brown with green shiny scales, the females are more yellow-brown. Targeted breeding, however, has made almost every imaginable color combination possible. With a body length of 5 to 7 cm and the particularly wide fins, the coloring comes into its own.
Because of their pronounced territorial behavior, Betta splendes should be kept in pairs or in small harems. If the fish are too stressed, they sometimes fight their own reflection. Opportunities to retreat are therefore particularly important to them, so the tank itself can be relatively small, but at least 50 liters. The size of the aquarium always depends on the number of animals. When it comes to the water quality, the Siamese fighting fish are satisfied with a normal tropical 24 – 30 °C and a pH value of 6 to 8.
Peculiarities when keeping fighting fish and in the aquarium
The territorial behavior of the fighting fish is not necessarily exceptional. Perch and other harem-forming fish species also tend to fight their sex competitors. From a black eye to bitten fins to a life-or-death struggle, anything is possible. Betta fish just go to extremes most of the time.
The equipment of the pool is all the more important. With a suitable selection of aquatic plants (e.g. Java fern), roots and stone caves, it should offer sufficient opportunities for retreat as well as hiding places and spawning grounds. At the same time, the long, flag-like fins must not get caught in it – so you have to pay attention to the right structure.
Most bettas prefer additional floating plants, which on the one hand dim the light and on the other hand allow them to gasp at the water surface protected but unhindered. Floating plants are also ideal for building foam nests underneath. However, access to the water surface must always be free. Confined aquariums with all sorts of decorations or a dense plant cover are not recommended.
A water volume of 50 liters is the minimum for a couple. The aquarium should definitely be larger for keeping harems and additional species of fish in order to ensure species-appropriate keeping. Artificial currents are generally not necessary, but should definitely be avoided on the water surface with foam nest breeders.
Ideally, the air directly above the water surface should correspond to the water temperature. If the fish gasp for oxygen with their upper mouth, they could quickly catch a cold and become seriously ill if the temperature is too low. A water-close lid keeps the tropical warmth well contained. It also protects erratic fish from certain death in the dry.
A special blackwater aquarium is particularly good for some types of fighting fish. This is basically a freshwater aquarium designed to emulate tropical conditions with low-salinity, soft water quality. At the same time, peat is added to optimize filtering. This is how the typical darker water color is created.
Otherwise, bettas have almost the same requirements for their species-appropriate keeping as other freshwater fish: controlled lighting conditions, stable, warm temperatures, filters and regular partial water changes as well as a bit of aquarium care.
In the wild, Bettas feed on mosquito larvae, water fleas, and other small insects and molluscs. They usually hunt them directly in the water or as approaching food, which lands on the water surface or can be snapped directly above it. In short: bettas are pure carnivores.
In the aquarium they also prefer live food, especially small crustaceans such as daphnia and artemia. However, from time to time it can also be dry fish food in the form of flakes, tablets or granules. Frozen food is also accepted.
Adult animals should not be overfed. A day of fasting does no harm either, because they tend to become obese.
Freshly hatched juveniles, on the other hand, tolerate dust food, artemia nauplii and parameciums very well. After about three weeks of rearing, they can be switched to the usual food animals.
Socialize fighting fish
Depending on the degree of aggressive behavior, bettas are kept in pairs (1 male and 1 female) or in harems (1 male and 3 to 4 females). Several males each need their own territory and corresponding space in the aquarium. In some species, such as the Betta smaragdina, males can rarely be socialized with one another, provided they have grown up together. On the other hand, the females are not always peaceful among themselves. Keeping them in pairs is particularly recommended for Siamese and maroon fighting fish.
In order to stimulate or prevent reproduction, the courtship behavior can be influenced by means of the water temperature. During courtship, the fighting fish naturally show their most beautiful side. They really bloom and the whole aquarium becomes a wonderfully colorful underwater world. Sometimes, however, the males can be quite pushy. A selection of several females as well as sufficient retreat possibilities allow the animals to live together without aggression during such “hot” phases.
With a suitable tank size and sufficient food supply, the rearing of the juveniles is completely peaceful, regardless of whether they incubate in the foam nest or in the mouth. Basically, the male, i.e. the milker, takes care of the brood. As the offspring grow up, however, they must be separated from the harem in good time in order to avoid any fights between old and young animals.
Combinations with other fish species should also always be considered. Guppies, for example, are no-go candidates. The guppy males in particular are seen as competitors and attacked because of their similar appearance. The same applies to other colorful, long-finned fish species.
Lively or very active animals also disturb the bettas. The emerald fighting fish in particular are very shy and skittish. Turbulent back and forth would mean too much stress for them, which would either result in aggression or in the form of illnesses or a short life expectancy. Bettas naturally only live to be 3 to 4 years old.
Fish species of the same size to slightly smaller that behave calmly and stay in the lower area of the tank are definitely suitable for socializing with bettas. These include, for example, armored catfish and danios.
In conclusion, for betta keeping, a well-stocked species tank is the best way to observe their magnificent beauty and highly interesting behavior.