Siamese fighting fish
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 A cambodian colored (light body, dark fins) veiltail male.
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| Betta splendens Regan, 1910 |
The Siamese fighting fish (Betta splendens) is one of the most popular species of freshwater aquarium fish. It is a member of the gourami family (family Osphronemidae) of order Perciformes, but was formerly classified among the Anabantidae. It is native to the Mekong basin in Southeast Asia.
The natural colouration of B. splendens is a dull green and brown, and the fins of wild specimens are relatively short; brilliantly-coloured and longer-finned varieties have, however, been developed by breeders (see Appearance, below.)
As B. splendens is the Betta species most commonly known to aquarium hobbyists, it is often but imprecisely sold as, and referred to, simply as "betta" (as a common name), particularly in the United States. The name "betta" can, however, also refer to any of the nearly fifty other members of the genus, including the type species, the spotted betta (B. picta). The fish is known as pla-kad in its native Thailand.
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[edit] Appearance
B. splendens grows to an overall length of approximately 6 cm (~ 2.3" in), and has an average life span of four years. Well kept aquarium specimens have often lived well beyond six years. There are reports of captive Bettas living ten or more years in laboratory settings.
In Asian countries they have long been used in a sport similar to cockfighting, where it was necessary to have aggressive short-finned fish. Today, by selective breeding, it is not uncommon to see B. splendens with an array of colors and tails. Both female and male Bettas are now available in many colors, with new strains being developed constantly by dedicated breeders around the world. Females never develop finnage as showy as males of the same type, and are almost always more subdued in coloration. Also, the temperaments of both sexes are varied. Though males on average are more aggressive, some females have proven more aggressive than their male counterparts. See Behaviour.
[edit] Tail shapes
Breeders have developed several different tail shapes, the most common being "veiltail". Others include crowntail (highly frilled), half-moon (large tail fin that forms a half circle), short-finned fighting style (sometimes called "plakat"), and double-tail (the tail fin is split into two lobes). Double-tail Bettas also have a significantly elongated dorsal fin.
[edit] Colors
Bettas have been affectionately nicknamed "The Jewel of the Orient" due to the wide range of colors, which are produced through Selective breeding. Reds and dark blues are the easiest colors to purchase, being fairly hardy, and often breed true.They come in all colors such as magenta, Orange (developed by master World Champion betta breeder Gilbert Limhengco), Yellow (rare), and emerald green. Breeders have also developed different color patterns such as marble and butterfly, as well as metallic colors such as copper, gold and opaque.
[edit] Behavior
Both instinctive and learned behaviors of B. splendens have been studied in considerable detail. Its characteristic aggressive responses were studied in detail by Simpson (1968). They are readily elicited by its own reflection in a mirror placed outside an aquarium. Male Bettas flare their gill covers, called the opercula (sing. operculum), in response to certain situations. Flaring is the act of "puffing-out" the fins and gill covers as to appear more impressive, either to intimidate other fish (especially rival males) or as an act of courtship. Females will display horizontal bars (unless they are too light a color for this to show) if stressed or frightened, as will males. There have been instances of female bettas flaring, although this is much less common. Flirting fish behave similarly, with vertical instead of horizontal stripes indicating a willingness and readiness to breed.
The capacity to turn aggressive behavior on and off by using a mirror, without putting the subject at the risk of physical damage inherent in staging an actual aggressive conflict, made the fish a popular subject of study by ethologists and comparative psychologists interested in studying aggression. There was a stream of research on the fish's aggressive behaviour from the 1970s, though this has reduced lately, partly because of new approaches to studying aggression arising out of sociobiology, and partly because it was realised that, even if no tissue damage was done, repeatedly eliciting aggressive responses in the fish might be a source of stress. Interesting results were obtained, however; for example, it was shown that the presentation of such an aggression-eliciting stimulus will act as an unconditional stimulus in classical conditioning, and as a reinforcer in operant conditioning (Thompson, 1966). It is as if the fish finds the opportunity to attack another fish rewarding.
Other research has investigated the efficacy of tranquilizers in eliminating B. splendens’s fighting response[1] and the fish’s opponent assessment behaviour.[2] [3]
Under the right temperature range, (24-29°C, or 75-84°F) bettas are normally very active fish. They have good eyesight and will learn to surface for feeding time when a hand appears over the bowl and other simple recognition tools. During darker parts of the day, they may "sleep" or rest on the bottom of the tank or just under the surface where they can breathe. Bettas are very territorial and require a place to hide, even if there are no threats. They will cling very close to any plant or rocky alcove they can find, becoming highly possessive of it.
[edit] In the aquarium
Because of its beautiful colours and fin shapes, the Betta is popular with aquarists.
Members of the genus Betta, to which the Siamese fighting fish belongs, are a type of "labyrinth fish" (a name also given to anabantids) because they have a labyrinth organ in their heads that allows them to take oxygen directly from the atmosphere in addition to the oxygen taken from water via their gills. This flexibility allows these fish to survive in smaller spaces and in poorer conditions (e.g., in stagnant water) that wouldnt support other aquarium fish. An important thing to know when housing a "betta splendens" is that most metals are lethal, and never should metal decorations be used unless they are marked for this purpose. Copper is especially dangerous. Nonetheless, to keep an individual B. splendens, a minimum tank size of 3 U.S. gallons at least is recommended, if it will be kept in a warm room. Some authorities maintain that for a betta to lead a happy life and live the maximum lifespan, as much as 35 litres (10 U.S. gallons) is necessary.[4] This absolute minimum ratio (8 litres/fish) holds true for both females and males who are being housed individually as well as females who are being housed together; this means that the smallest tank that can become a female community tank is 35 litres (10 US gallons), which can hold three or four females. A tank of 22 litres or larger (6 US gallons) will allow use of a heater, to maintain a temperature of about 27 °C (81 °F). It is optimum to keep the pH levels of the water between 6.5 and 7.5. One must take care in monitoring the pH levels to ensure the health of the fish, specifically if CO2 injection is being used in a planted tank, which can result in rapid spikes of pH values. The floor of the tank should have, as a minimum, a thin (5 mm or 0.25 in) layer of gravel to increase the surface area for nitrifying bacteria to colonize. Decorations can provide hiding places, especially important when two males are housed in a divided tank, or when the betta is living in a community tank. Every decoration must be free of rough areas or sharp points which can damage the delicate fins of the betta—for this reason, silk rather than plastic plants are recommended. Live plants will improve the water quality. Also, since the betta obtains oxygen from the air, the tank must not be covered with an air-tight lid and the betta must be able to easily reach the surface. (Note that some bettas enjoy leaping out of tanks, so a breathable lid is highly recommended.) If the betta has no access to air, it will suffocate.Be careful of housig it with small fish, for it will sometimes kill or eat them.
In Canada and the United States, the Betta is sometimes sold in a vase with a plant, with the erroneous claim that the fish can feed on the roots of the plant and that it can survive without changing the water. This is dangerous for the betta in two ways. First, the betta has a labyrinth organ which allows it to take in oxygen from the surface air, similar to the human lung. If the betta can not reach the surface of the water, which can be the case if a plant's roots are covering the surface, the betta will suffocate in a matter of hours. Secondly, Betta species are carnivorous and an appropriate food must be provided, such as dry "betta pellets" or live or frozen bloodworms or brine shrimp. However, most aquarium-bred specimens can subsist on dried flaked food suitable for tropical fish, though this will reduce their coloring somewhat. When kept in a small container such as a vase, the fish need frequent water changes, and the container must be kept in a warm room. A larger tank with a heater will provide better living conditions. Wherever the fish is kept, water must be treated with an appropriate water conditioner before use.
Betta males are the ones to raise the fry (baby bettas) and will, even when not in presence of female or fry, build bubble nests of various sizes and thicknesses on the top of their tanks. Various things have been shown to stimulate bubble nest construction, such as quick temperature change, barometer changes, materials in the tank and presences of other males or females.
Bear in mind that fish with 'fancier' tail forms such as half-moons can be more difficult for the novice aquarist to keep in optimum health.
There is a stereotype that in the wild, bettas live in tiny muddy pools, and therefore that it is acceptable to keep them in small tanks, but bowls are usually too small. In reality, bettas live in vast paddies, the puddle myth originating from the fact that during the dry season, the paddies can dry out into small patches of water, thus enabling their easy capture by humans. It is not a natural state of affairs by any means, and in the wild, fish trapped in such puddles are likely to die in a short period of time when they dry out.
To maximize the lifespan of the fish and ensure their wellbeing, they should always be kept in appropriate sized tanks. As a rule of thumb, for each inch of fish there must be at least one gallon of water in its tank. Bettas idealy should be kept in a filtered tank 10 gallons or more and treated like any other freshwater tank fish. Although these conditions are ideal, with proper care and filtration a betta can be happily kept in a smaller tank.
[edit] Tankmates
Because of the aggressive nature of this species, tankmates must be chosen carefully, and two male B. splendens should not be housed in the same tank unless they are separated by a dividing wall. As a general rule, male Bettas cannot be housed together. It is possible to house two male bettas in a single very large tank, provided that there is plenty of cover (such as floating plants) and enough space for both males to establish their own territories. However, this is an extremely risky procedure because of the male's natural territoriality. These experiments in housing males together often end in the death of one or both inhabitants of the tank. (Male bettas do not 'fight to the death' in the wild; once one fish has clearly won the encounter, the loser will retreat to a safe location. In an aquarium, however, there is no place to run, and the winning fish will continue to attack the loser, often ending in death.)
While they might eventually mate, keeping a male and female together may prove too volatile since the male will often be much more aggressive and mating conditions must be precisely conducive. Often, breeders have a special container so the female may display without being harmed by the male prior to induced breeding.
Females may or may not be able to coexist peacefully in the same tank depending on their temperaments. They are not schooling fish, and are still rather aggressive, but with enough room and many hiding spaces, they can learn to get along. There should never be exactly two female bettas in a tank together—a pecking order, a hierarchy, is necessary for them to live peacefully. With only two fish, one will be the bully and the other will be picked on. However, with three or more, a hierarchy is established.
Before co-housing Siamese fighting fish with other species, their compatibility should be carefully researched, and the owner should have a back-up plan if the shared tank does not work. Common tankmates include mollies, catfish, or loaches. Although bettas are most aggressive towards each other, they have been known to kill very small fish or nip at the fins of fish such as fancy guppies, perhaps mistaking their finnage for that of another male betta. Certain fish should not be housed with bettas. Schooling fish often become fin-nippers, making the betta a prime target because of their flowing fins. Also, aggressive fish like barbs should not be around bettas. Keepers have also reported problems when attempting to keep Betta in the company of piranha, or bluegill for obvious reasons. It is strongly recommended that bettas given tankmates should be housed in a tank that is at least 2 gallons per fish in the community (depending on bio load) with plenty of hiding places. Anything smaller will stress the Betta. Only females can be kept in communities, and you still must watch out for aggressive females who will cause trouble in your tank.
[edit] Lifespan and diet
Normally betta live to be 2-5 years old, but some betta fish live to be nearly 8 years old. However, when purchasing from a pet store, it is not always possible to know how old the fish is when you take it home. Typically, males are 9 months to one year old, as this is when their finnage becomes fullest and most attractive. Females can be much younger, as young as 3 to 6 months, due to their shorter finnage. Male bettas living in laboratories with large individual tanks and daily exercise have lived 10 years or longer.
Carnivorous, the betta feeds on zooplankton and mosquito and other insect larvae. Domesticated bettas will feed on bloodworms, daphnia, and brine shrimp. Betta pellets are typically a combination of mashed shrimp meal, bloodworms, and various vitamins to enhance color and longevity. For variety and fiber, bettas may also be fed finely chopped vegetables high in protein such as soybeans, green beans, broccoli, corn, or carrots.
Bettas are primarily surface feeders, because their mouths are upturned, so any food added should be able to float on the surface of the water.
Bettas fare better with a large variety of foods and will often show brighter, richer, and deeper colors if they are fed a wide range of foods. They will also heal much more quickly from fin damage if their diets are high in protein and fiber.
Two common maladies afflicting Siamese fighting fish are fin rot and ich.
[edit] Ideal tank conditions
Since bettas are from the rice paddies of Southeast Asia, they typically thrive in conditions somewhat similar to their origins. In the wild, the Siamese fighting fish inhabits standing or slow-moving water, including floodplains and rice paddies, at temperatures of 24 to 30 °C (75 to 86 °F). This level of temperature should be used in the aquarium. Colder water temperatures could lower the bettas' immune system and cause illness. The pH level should range between 6.5 and 7 (slightly acidic). Peat moss can be safely used to create softer acidic water since bettas are fine with water that is slightly tannic.
The most important factor in maintaining their ideal tank set-up is that bettas require consistent conditions. They are easily stressed by sudden changes in temperature, pH, or bacteria. Also, bettas may be allegic to certain types of natural/synthetic plastics, such as thermosets, elastomers, and thermoplastics.[citation needed] Be sure to ask your local fish store what tank is right for your betta.
[edit] References
- ^ Walaszek, E. J., and L. G. Abood (1956). "Effect of Tranquilizing Drugs on Fighting Response of Siamese Fighting Fish". Science 124: 440‒1.
- ^ Bronstein, Paul M. (1983). "Agonistic Sequences and the Assessment of Opponents in Male Betta splendens". American Journal of Psychology 96 (2): 163–77.
- ^ Oliveira, Rui F., Peter K. McGregor, and Claire Latruffe (1998). "Know Thine Enemy: Fighting Fish Gather Information from Observing Conspecific Interactions". Proceedings: Biological Sciences 265: 1045‒9.
- ^ Marcus Song, Caring for Betta Fish (Lulu Press, 2006). ISBN 1-4116-9365-5
- Betta splendens (TSN 172611). Integrated Taxonomic Information System. Accessed on 19 March 2006.
- "Betta splendens". FishBase. Ed. Ranier Froese and Daniel Pauly. November 2005 version. N.p.: FishBase, 2005.
- Simpson, M. J. A. (1968). The display of the Siamese fighting fish Betta splendens. Animal Behaviour Monographs, 1, 1-73.
- Thompson, T. (1966). Operant and Classically-Conditioned Aggressive Behavior in Siamese Fighting Fish. American Zoologist, 6, 629-741 (doi:10.1093/icb/6.4.629).
[edit] External links
- Bettas at the Open Directory Project (suggest site)
