REVIEW ARTICLE

doi: 10.2306/scienceasia1513-1874.2009.35.008ScienceAsia35 (2009): 8–16

The Siamese fighting fish: Well-known generally butlittle-known scientificallyAdisorn Monvises, Bunlung Nuangsaeng∗, Namkang Sriwattanarothai, Bhinyo Panijpan

Institute for Innovation and Development of Learning Process, Mahidol University, Rama 6 Road, Bangkok10400, Thailand

∗ Corresponding author, e-mail: nbunlung@hotmail.com,nuangsaengbunlung@yahoo.comReceived 22 Jul 2008

Accepted 14 Feb 2009

ABSTRACT : The Siamese fighting fish, of whichBetta splendensis representative, is gaining popularity as judged byincreasing export values and demands for novel types worldwide, especially the ornamental ones. However, relatively littleis known about the bettas scientifically. In this review we cover what is known about the desired morphology and pigments,genetics, aquaculture, diseases and feeds involved in breeding bettas. We also propose breeding the bettas for domesticenjoyment and export by exploiting current knowledge of gene technology and molecular developmental biology in additionto the use hitherto of only classical genetics. Other aspects of fish culture such as feeds, disease prevention and water qualityshould also be scientifically studied and improved upon. Because of dwindling and worsening habitats in Thailand, morestudies on biodiversity and work towards species conservation of the wild types are needed.

KEYWORDS : betta, pigments, genetics, diversity, conservation

INTRODUCTION

The Siamese fighting fish is found not only in Thai-land but also in other neighbouring countries in SEAsia. Because of the male’s pugnacious nature andbeauty, the representative fish is calledBetta splen-dens(the splendid battler). Traditionally, Thais loveto watch and bet on two combating males, with fightssometimes resulting in death. The market for thistype of fish, which has been ongoing since recordedhistory1, has not changed much. Fish bred for fightingare selected for a large and strong body with hardscales (hard targets) but smaller fins (flimsy targets) asprotection against bites of the opponent. Here coloursand patterns are of secondary importance. Ability tobite vulnerable targets such as the swimmers and tailfins (for stability and kicking ability) is a very crucialasset.

Breeding the males as ornamental fish for localsale and exporting is also becoming increasingly lu-crative. The features favoured by aficionados andamateurs alike are colour intensity, colour pattern,scale iridescence, body shape, and fin size. Changingthe emphasis of breeding from fighting to ornamentalbettas is preferable not only for ethical reasons butalso for commercial reasons in that the export marketfor the latter is larger and has higher profit margins.According to the Department of Fisheries (2000–2005), bettas ranked among the top two ornamentals

in terms of number of fish and revenue. The latestofficial value (2005) for bettas is about 25 millionThai baht. This figure can be improved upon. Inraising the fish for high quality mass export, waterquality in the breeding jars, feeds, disease prevention,better transport conditions, and certification will be ofutmost importance.

Although wild types are eagerly sought and com-mand high prices as breeding stocks for the fightingbettas, it is the ones bred in captivity that bring out-ward varieties to other commercial bettas. Ornamentalfish with novel colours, colour patterns, and finsare regularly imported and are in high demand untilextensive local propagation brings the prices downfrom 10,000–20,000 to 10–20 Thai baht each. Thesevarieties probably still arise from classical breedingand selection (personal communication). It appearsthat traditional betta breeders still base their thinkingon classical Mendelian genetics in spite of constantdemands for new features by the market. AtisonPhumchoosri, a prominent betta expert, believes thatbreeders still exchange information and keep theirown practice-based experiences and beliefs that maynot have any scientific foundation.

Although this article is written by Thai biologistswith experience mainly in Thailand, we recognizethat other scientific communities, especially those inSE Asia, have similar challenges and problems andwill benefit from all the aspects addressed in this

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Fig. 1 Bettas found in Thailand: (top) B. splendens,(middle) B. smaragdina, (bottom) B. smaragdinamalewrapped around female during spawning.

review. We would therefore like to persuade Thaiscientists and others in the region to work more ontheir native fish for original scientific contributions, toinnovate ways to make this fish more ornamental forenjoyment and export, and to conserve their habitatsand diversity. We have selected certain topics deemedrelevant to breeding for specific aesthetic proposesand commercialization at the expense of other topics.Proposals are made here to highlight aspects that wethink should be prioritized by biologists and breeders

Fig. 2 Bettas found in Thailand: (top) B. imbellis, (middle)Bettasp. Mahachai, (bottom) B. prima.

who wish to make contributions for future knowledgeas well as raising bettas.

CLASSIFICATION

The most recent classification of bettas from phyloge-netic evidence2–4 places them in the Osphronemidaefamily (whose freshwater members areAnabasspp.,Trichogasterspp., andTrichopsisspp.), Macropodusi-nae subfamily and genusBetta. Thus far 55 species ofbettas have been described from Indochina5. Each onedisplays one of two different types of egg broodingcare (nest building and mouth brooding). Of all the10 wild-type species found in Thailand, 4 are bubble-nest builders and 6 are mouth brooders. Goldstein6

and Linke7 have written about the 4 species of wild-type bubble nest builders in Thailand as follows.

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Fig. 3 B. splendensvarieties bred in Thailand: (top)multicoloured crown tail, (middle) red double tail, (bottom)opaque white halfmoon.

B. splendensRegan, 1910 is the most well-knownand the most widespread in the Central Plain. Itshabitats are small bodies of water such as those inpaddy fields, ponds, lagoons and marshes.

B. smaragdinaLadiges, 1972 is found throughoutthe Northeastern region, e.g., provinces of Nong Khai,Udon Thani, Khon Kaen, Loei and Ubon Ratchathani.Paddy fields, marshes, ponds and lagoons are places itcan be found.

Fig. 4 B. splendensvarieties bred in Thailand: (top)pineapple short tail, (middle) marble short tail, (bottom)orange short tail.

B. imbellis Ladiges, 1975 is ubiquitous in theSouthern regions, e.g., provinces of Phuket, SuratThani, Nakhon Si Thammarat and Songkhla, theMalay Peninsula and Penang Island. Shallow watersof paddy fields, marshes, ponds, lagoons, lakes andacidic swamps are the habitats. However, it can alsobe found in areas where the water is brackish due tothe ebb and flow of the sea tide.

B. sp. Mahachai is distributed only in a narrowand specific area of Samut Sakhon, Samut Songkhramand Samut Prakarn. It is found in tidal brackish waterswith thick vegetation. No other wildBetta species

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have been found in the area. It has not yet beenclassified. The possibilities remain that it is a newand still unestablished species or a hybrid species bredtrue.8 The authors are studying it for diversity andconservation purposes.

As for the wild-type mouth brooders, Schindlerand Schmidt5 made a survey in Thailand and reported6 species as follows.

B. prima Kottelat, 1994 is widespread in theEastern region, e.g., in Chonburi, Trat and Sa Kaeo. Itis found in slow-flowing streams, lagoons and ponds.

B. simplexKottelat, 1994 is found in the Krabiprovince in the South. However there are no reportsso far from other provinces nearby. It can be foundin spring-fed streams with slow flowing waters withdense vegetation.

B. pi Tan, 1998 is found in Su-ngai Kolok districtand Tak Bai district of Narathiwat province in peatswamps and flooded areas on river banks together withdecaying vegetation.

B. pallidaSchindler & Schmidt, 2004 is found inthe Ruso and Su-ngai Kolok districts of Narathiwatprovince and Ko Samui of Surat Thani province inshaded shallow waters with decaying vegetation.

B. apollon Schindler & Schmidt, 2006 was re-cently reclassified. It is ubiquitous in the Narathiwatprovince in shallow waters of mountain streams witha depth of about 20–30 cm.

B. ferox Schindler & Schmidt, 2006 was alsorecently reclassified. It can be found around ParibatraFall, Hat Yai district, Songkhla province. It lives inslow flowing streams around tree roots andAcaciaplants.

To conclude this section, we wish to mention thelittle known B. sp. Satun which is a less colourfulmouth-brooder of southern Thailand.9 Its habitats areeasy-flowing rivers in the hilly landscape northeast ofSatun. It has glowing and vigorous turquoise greenon the lower head. It may belong to theB. pugnaxcomplex.

CONSERVATION

Foresight and better knowledge are needed to keepwild bettas in their habitats and to keep domesticatedones as diverse as possible while developing newvarieties.

We and our colleagues have surveyed Thailandfor habitats and diversity of bettas and our combineddata are shown inFig. 5. The last 20–30 yearshave witnessed a dwindling of habitats such as ponds,paddy fields and swamps due to urbanization andindustrialization. In response, we need: (1) a de-tailed catalogue of all localities withBetta species

Fig. 5 Distribution of (top) four species of wild-type bubblenest builders and (bottom) six species of wild-type mouthbrooders in Thailand.

or subspecies (2) gene banks and preserved specimendeposits for all the catalogued species or subspecieswhere scientists may conduct continuing research onthe bettas (i.e. systematics) (3) institutes in whichto conduct research on the natural history of bettas.This will allow for a species maintenance programmefor vulnerable or threatened species (by locality not

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phenotype). Also, asB. splendenshas proven to bea good model for domestication and mass productioncontributing to a significant segment of the fisheriesindustry, it follows that such institutes should havea role in helping technology transfer to fish farmersfor the aquaculture of all bettas. Incidentally, weshould be careful about divulging the exact locationsof rare species in case of poaching, although there hasbeen no precedent for collecting bettas to extirpation.Nevertheless, severalBetta species have variouslybeen listed as critically endangered (B. sp. Mahachaiand B. simplex), vulnerable (B. prima and B. pi)and threatened in situ (B. imbellis, B. smaragdina,and B. splendens)10. Thus far, a number of wildforms of bettas has been domesticated and incorpo-rated into farming programmes to serve the exportindustry. The greatest demands are forB. splendens,alsoB. smaragdina, B. sp. Mahachai,B. imbellis, allnest building bettas. The mouth brooding species arein a small-demand niche market and not as popular.One particular population that is easily impacted isB. simplexas it is in a microhabitat. The main threatsare from tourism, agriculture, elephant camps, andspring water spas. The protection of habitats has tobe instituted soon.

CLASSICAL AND MOLECULAR GENETICS

To conserve and develop bettas, knowledge must beaccumulated about their genomes and various pheno-types resulting from gene expression.

The classical genetic basis for the pigments ofB. splendenswas first published in 193411. Usingstatistical analysis of betta scale pigments, Wall-brunn12 found that the body, fin, and scale coloursof B. splendenswere regulated by genes for melaninand iridescence pigments as well as the genes forpigment density. The gene for iridescence completelydominates that for melanin.

Khoo et al13 studied sarcoplasmic protein pat-terns of B. splendensby isoelectric focusing andfound little differences, probably arising from lowgenetic diversity. After comparing hatchery stocks ofB. splendensin Nakorn Pathom province by studyingtheir allozymes, Meejui et al14 concluded that thegenetic diversity of hatchery populations of Siamesefighting fish in Thailand was marked with a slightdecline in allele diversity and proportion of polymor-phic loci while heterozygosity increased. However,sufficient genetic diversity existed among populationsand would greatly benefit genetic improvement pro-grammes of this species. They recommended keepinggenetic integrity of each population by minimizingstock translocation between genetically distinct pop-

Fig. 6 Fragments of mitochondrial (mt) DNA sequencesof Bettaspp.,Trichopsis, andTrichogaster. The completesequences include partial 12S (mt) ribosomal RNA, whichis connected to the complete tRNA-Val and partial 16Sribosomal RNA sequences. Stars indicate identity positions.

ulations.Recently work has begun on the taxonomy and

population structure of bettas using genetic markersof mitochondrial and nuclear DNA sequences3. Thestudies are the ones that showed bettas to be inthe Osphronemidae family. It was also found thatthe B. splendensnesters are genetically more closelyrelated toB. imbellisthan the others whereas theB. pibrooders are genetically close toB. simplex(seeFig. 6and phylogenetic tree in Ref.3) as supported by anRAPD study15.

REPRODUCTION AND PROPAGATION

Breeding fish to obtain the desired characteristicsrequires knowledge of the lineage of both male andfemale. The pair must be placed in a jar with properdimensions in the presence of vegetation. The depthof water used should not exceed 15 cm so that thehatched fry that tend to sink can come up to thesurface to breathe6. Yucca and tropical almond leaf(Terminalia catappa) extracts (the active ingredientsin, e.g., Atison’s Betta spa, Ocean Nutrition) are usedin the spawning vessel with the aim of ridding bodywaste and, in particular, ammonia.

Usually, in situ infusoria and purchased waterfleas (Daphniasp. andMoina sp.) are used as naturalfeeds for the fry. However, some fish tanks may nothave sufficient infusoria, in which case artificial feedshave to be used. Artificial feeds for young fish (whichmay number up to 500 per litter) are selected by theirparticle size and nutritious value, e.g., yolk of boiledegg mixed with water or mixed with standard feedssieved to obtain only particles small enough for them.DecapsulatedArtemiacysts have to be ground beforemixing with floating material for efficient use as feed.Feeds of different sizes are used at various stages ofdevelopment to ensure good health and survival.

At about two months after hatching, males aremorphologically distinguishable from females. To

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keep the males from fighting, 4-month old malesmay have to be isolated. At the farm level, pricesare then fixed for the beauty or fighting abilities ofrepresentatives of the litter. Because of their lacklustrecolours and display, females are usually sold en masseat a very low price; only some are kept for breeding.Breeders then use some of these fish with the desiredcharacteristics to further propagate the lines.

PIGMENTS AND BODY COLOURS

Pigments of bettas give rise to red, blue, green,and yellow body surface colours and also to scaleiridescence. Pigments are compounds of the gen-eral structures such as melanins, carotenoids, xan-thines and pterins whereas iridescent compoundson the scales and body surfaces are guanines andpurines.16 These pigments are also common in otheranimals. However, fish have special pigment cells(chromatophores) which respond to neural signals forquick outward expression by deepening of colourintensity and changing of shades17. The genetic basisand synthetic routes to these pigments have not beenwell established, let alone the interactions betweenthem. However, Braasch et al18 studied an ancientfish-specific genome duplication (FSGD) by using acomparative genomic approach for two major pig-ment synthesis pathways (melanin and pteridine) inteleost fish. Due to the FSGD, teleost fish apparentlyhave a greater repertoire of pigment synthesis genesthan other vertebrate groups. These results supportthe important role of the FSGD and other types ofduplication in the evolution of pigmentation in fish.Therefore, to successfully and systematically breedbettas and/or to specifically modify bettas geneticallyusing gene technology the relevant basic science hasto be done. Developmental biology and molecularbiology techniques should help to produce desiredbody colour patterns on demand.

The chromatophores of fish change colours in ac-cordance with the habitat, the environment and stim-uli. 19 There are two types of chromatophore, thosethat absorb lights in the visible range (melanophores,erythrophores, xanthophores and cyanophores) andthose that reflect light (leucophores and iridophores).The pigments are moved intracellularly by motorproteins such as tubulin, dynein, and kinesin17.The pigment cells respond to brightness, ultravio-let light, pressure, temperature, fish activity, pH,and chemicals via the neurohumoural and neuro-chemical systems producing melanophore-stimulatinghormone, adrenocorticotrophic hormone, prolactin,somatolactin, melanin-concentrating hormone, mela-tonin, epinephrine and norepinephrine.17,19–21

In vertebrates, pigment cells develop from theneural crest of the embryo22,23. In the epidermis anddermis there are four pigment types: iridescent orblue, black, red, and yellow, which are made up of,respectively, blue and green pigment-containing irido-cytes and guanophores, melanophores, erythrophores,and xanthophores. The pigmentation is controlledby genes giving rise to different types, quantities ofpigments, and pigment distributions.

During development, one can easily observechanges in the outward appearance of the fish atdifferent stages. The early hatchlings have no spotson the yolk sac which is attached ventrally. The pre-larval stages also have no or very few coloured bodyspots. Only at the post larval stage do the fry havedispersed colour spots all over the body24.

AGGRESSIVE BEHAVIOUR

Another factor that may pose problems for big scalebreeding and propagation is the excessive aggressivebehaviour of bettas raised in a litter, especially forthe ornamentals, because they need an appearanceuntouched by biting.

Bettas are social animals capable of living ingroups with a pecking order25 or in isolation. Theyare very territorial, especially after isolation or duringcourtship. Their aggressiveness is usually expressedby body colour intensity, expansion of fins, and open-ing of gill covers (opercula), which are all featurespreferred by the females26–31. Although such expres-sions give rise to the splendours of the fish and theobsession of gamblers on results of their fighting32,people who raise them as ornamentals would prefer tohave such beautiful displays with minimal fighting26.Hence breeding out the aggressiveness or geneticallymodifying the fighting tendency would make keepinghome-based bettas in large groups a better prospect,instead of only in isolation as generally practised.Success in this direction would enhance their positionas truly ornamental. In trying to tone down the maleaggressivity, one has to keep in mind that the malecourtship display should still be effective.

Published results document attempts to enhancethe number of males per litter or to make the fe-males look more colourful33–35. In Thailand, breedershave used a variety of concoctions to enhance themale/female ratio, e.g., mangosteen (Garcinia man-gostana) leaf extract.36 Much work on betta aggres-sion has looked into the general sociobiological andpsychological aspects of behaviour rather than the fishthemselves37–41.

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DISEASES AND THEIR PREVENTION

For long-term keeping and breeding and also forcommercial transport, diseases due to microorganismsshould be prevented. Male bettas (one per bag)being sent to local markets and for export often sufferfrom limited oxygen in their containers. Sometimes,individuals in plastic bags have about 10 ml of air perfish (water to air volume ratio, 1:3) for up to 5 daysstarting from packaging to shipment and sale. Forthe export markets, generally plastic bags containing60 ml (for short fins) and 120–150 ml (for long fins)in Styrofoam boxes42 are used while maintaining thewater to air ratio of 1:3 for 1–3 days or 3:5 for4–7 days from preparation to destination (personalcommunication). These fish survive quite well dueto the labyrinth above their gills, an organ whichacts as an internal air reservoir and for the adjust-ment of their metabolism. Nevertheless, they stillsuffer from microbial and viral attacks43–45. TheDepartment of Fisheries of Thailand is developing amore rapid and specific diagnosis for pathogens inaddition to the external examinations for parasites andbacteria. Generally, acriflavin, gentian violet, andsodium chloride are used to prevent infection duringtransport of other fishes. Some of these and other low-cost antibiotics have also been used for bettas beingtransported.42 Anaesthesia and reduction of metabolicrates are two technical possibilities being exploited inmaking the fish dormant. This, in combination withnovel transport packaging, may reduce the overalllosses and costs.42 For sedatives, tricaine methanesulphonate (MS-222) at 60–70 ppm or quinaldine sul-phate at 25 ppm are generally used. Tetracycline (5–20 ppm) and neutral acriflavin (3–10 ppm) are popularamong Asian exporters. For stabilising water quality,buffers, zeolites, and activated carbon for capturingbody waste such as ammonia are used. Temperaturehas to be controlled by ice or heat pack for transport.Bettas usually cannot survive well in a cold climatemostly because of increased disease susceptibility.

For export, the Aquatic Animal Health ResearchInstitute of the Department of Fisheries, Thailand, hasthe duty of ensuring that the fighting fish be free fromdiseases such as ich (ick) or white spot disease (dueto the protozoanIchthyophthirius multifiliis), velvet orrust (due toOodiniumsp. protozoa), fin rot (due toPseudomonas fluorescensbacterium) and tuberculosis(due toMycobacterium piscium).

ARTIFICIAL FEEDS

Since natural foods are not widely available, for mostbetta lovers it is important to have artificial feeds

that are as close to the natural ones as possible.We therefore would like to encourage people to doresearch on this aspect.

Apart from artificial feeds for fry mentioned ear-lier, bettas favour live and moving prey, e.g., tinyinfusorium organisms, water fleas, blood worms, andespecially mosquito larvae6, 46. However, some ofthese are not easy to find in Thailand and some otherstransmit diseases. Mosquito larvae should not be keptjust for the purpose of feeding these fish; Japaneseencephalitis and dengue fever possibilities should con-stantly be kept in mind, even though the Ministry ofPublic Health has only warnings but no regulationsagainst raising them for commercial purposes. Thelarvae are generally of theCulex and Mansoniasp.which are potentially less harmful as disease carriersthan theAedesandAnophelessp.

Immobile feeds such as ant eggs and boiled eggyolk particles are not preferred by the fish, and theseare not widely available nor do they keep well. Al-though older fish can be trained to feed on artificialfeeds, there is still a need for artificial feeds whichare disease free with a good complement of nutrients.These feeds should be widely available and cheap,keep well and make the fish grow healthily withnormal body proportions6. Several commercial prod-ucts, e.g., those of the Sakura, Tetra, and Hikari, arecurrently available but they are relatively expensivecompared with feeds for other ornamental fishes suchas guppy, molly, and goldfish. An ideal artificial feedfor bettas should also be mobile on the water surfaceand/or sink very slowly.

RESEARCH IN THAILAND

There have been only a handful of publications inpeer-reviewed journals by Thai scientists. Karyotyp-ing of B. splendenshas been done and there is a goodagreement on the number of chromosomes (2n =42) but less on the types of chromosome47,48. Thesex chromosomes are also not easily distinguishablefrom autosomes49. A behavioural study of bettas in“natural” setting has also been reported. Two Thaiscientists, M. and K. Jaroensutasinee,50–52 found thatmale body size and nest size influences the femalechoice of mate. Larger males are better at courtshipdisplay than their smaller counterparts. Nest size alsoreflects the body size. During the mating season andthe parental care stage, the male is more aggressive.Two other pieces of work done overseas by Thaiscientists on microbes responsible for betta disease areworth mentioning here44,45.

As the subtitle of this review suggests, there isstill much that is not known about bettas. We have

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the fish locally yet most innovations and publicationscome from people overseas who do not have thefish in abundance. There is much opportunity forcommercial as well as scientific ventures, in additionto which the fish is part of the heritage of the region,and so is worthy of the attention of the local scientificcommunity.

Acknowledgements: We wish to thank Atison Phum-choosri and Horst Linke for their valuable contributions.

REFERENCES

1. Na Ayudhya P (2001)Secret recipes for raising andpropagating Siamese fighting fish[in Thai], NaewKasetagum Publishers, Bangkok.

2. Britz R (2001) The genusBetta — monophylyand intrarelationships, with remarks on the sub-family Macropodinae and Luciocephalinae (Teleostei:Osphronemidae).Ichthyol Explor Freshwaters12,305–18.

3. Ruber L, Britz R, Tan HH, Ng PKL, Zardoya R (2004)Evolution of mouthbrooding and life-history correlatesin the fighting fish genusBetta. Evolution58, 799–813.

4. Ruber L, Britz R, Zardoya R (2006) Molecular phy-logenetics and evolutionary diversification of labyrinthfishes (Perciformes: Anabantoidei).Syst Biol 55,374–97.

5. Schindler J, Schmidt J (2006) Review of the mouth-brooding Betta (Teleostei, Osphronemidae) from Thai-land, with descriptions of two new species. BibliothekNatur & Wissenschaft, Solingen.

6. Goldstein RJ (2004)The Betta Handbook, Barron’sEducational Series Inc., New York.

7. Linke H (1991) Labyrinth Fish: The Bubble-NestBuilders, Tetra Press, Melle.

8. Monvises A (2008)Bettasp. Mahachai, the green andelegant fighting fish whose identity is not yet estab-lished.Betta News4, 21–6.

9. Linke H (2008) Turquoise-green, magnificent Bettasfrom Southern Thailand.Betta News4, 12–4.

10. Vidthayanon C (2005)Thailand Red Data: Fishes,Office of Natural Resources and Environmental Policyand Planning, Bangkok.

11. Goodrich HB, Mercer RN (1934) Genetics and colorsof the Siamese fighting fish,Betta splendens. Science79, 318–9.

12. Wallbrunn HM (1957) Genetics of the Siamese fightingfish,Betta splendens. Genetics43, 281–98.

13. Khoo G, Loh EYF, Lim TM, Phang VPE (1997) Ge-netic variation in different varieties of Siamese fightingfish using isoelectric focusing of sarcoplasmic proteins.Aquaculture Int5, 537–49.

14. Meejui O, Sukmanomon S, Na-Nakorn U (2005) Al-lozyme revealed substantial genetic diversity betweenhatchery stocks of Siamese fighting fish,Betta splen-

dens, in the province of Nakorn Pathom, Thailand.Aquaculture250, 110–9.

15. Tanpitayacoop C, Na-Nakorn U (2005) Genetic vari-ation of Betta spp. in Thailand by random amplifiedpolymorphic DNA (RAPD) method. In: Proceedingsof the 43rd Kasetsart University Annual Conference,pp 185–92.

16. Bagnara J, Hadley M (1973) Chromatophores and pig-ments. In: Hoar WS, Randall DJ (eds)Fish Physiology,Academic Press, New York.

17. Fujii R (2000) The regulation of motile activity in fishchromatophores.Pigment Cell Res13, 300–19.

18. Braasch I, Schartl M, Volff JN (2007) Evolution ofpigment synthesis pathways by gene and genome du-plication in fish.BMC Evol Biol7, 74.

19. Sugimoto M (2002) Morphological color changes infish: regulation of pigment cell density and morphol-ogy.Microsc Res Technique58, 496–503.

20. Nilsson H, Wallin M (1997) Evidence for several rolesof dynein in pigment transport in melanophores.CellMotil Cytoskeleton38, 397–409.

21. Tuma MC, Gelfand VI (1999) Molecular mechanismsof pigment transport in melanophores.Pigment CellRes12, 263–94.

22. Kimler VA, Taylor JD (2002) Morphological studieson the mechanisms of pigmentary organelle transportin fish xanthophores and melanophores.Microsc ResTechnique58, 470–80.

23. Kelsh RN (2004) Genetics and evolution of pigmentpatterns in fish.Pigment Cell Res17, 326–36.

24. Hemsiri W, Termvidchakorn A (2001) Developmentand classification of young fish in 3 genuses:Trichop-sis, Betta and Trichogaster[in Thai]. Tech Rep 4/2001,Fisheries Museum Division, Department of Fisheries,Bangkok.

25. Snekser JL, McRobert SP, Clotfelter ED (2006) Socialpartner preferences of male and female fighting fish(Betta splendens). Behav Process72, 38–41.

26. Simpson MJA (1968) The display of Siamese Fightingfish, Betta splendens. Animal Behaviour Monographs1, 1–73.

27. Goldstein SR (1975) Observations on the establish-ment of a stable community of adult male and femaleSiamese fighting fish (Betta splendens). Anim Behav23, 1179–85.

28. Gorlick DL (1989) Motor innervation of respiratorymuscles and an opercular display muscle in Siamesefighting fish Betta splendens. J Comp Neurol290,412–22.

29. Malinowski J, Preuss W, Cantalupo C, Bisazza A, Val-lortigara G (1996) Lateralization of displays during ag-gressive and courtship behaviour in the Siamese fight-ing fish (Betta splendens). Physiol Behav60, 249–52.

30. Allen JM, Nicoletto PF (1997) Response ofBettasplendensto computer animations of males with finsof different length.Copeia1, 195–9.

31. Clotfelter ED, Curren LJ, Murphy CE (2006) Mate

www.scienceasia.org

16 ScienceAsia35 (2009)

choice and spawning success in the fightingBettasplendens: the importance of body size, display behav-ior and nest size.Ethology112, 1170–8.

32. Kelley DB, Gorlick DL (1990) Sexual selection and thenervous system.BioScience40, 275–83.

33. Badura LL, Friedman H (1988) Sex reversal in femaleBetta splendensas a function of testosterone manipula-tion and social influence.J Comp Psychol102, 262–8.

34. Kirankumar S, Pandian JT (2002) Effect on growth andreproduction of hormone immersed and masculinizedfighting fishBetta splendens. J Exp Zool293, 606–16.

35. Lowe TP, Larkin JR (2005) Sex reversal inBettasplendensRegan with emphasis on the problem of sexdetermination.J Exp Zool191, 25–31.

36. Phaichamnan U, Wattanakul W (2002) Effects of man-gosteen leaf extract on sexual characteristics of theSiamese fighting fish [in Thai], Rajamangala Univ ofTechnology, Bangkok.

37. Robertson CM, Sale PF (1975) Sexual discriminationin the Siamese fighting fish (Betta splendensRegan).Behaviour54, 1–25.

38. Miley WM, Burack G (1977) Strength of aggressivedisplay in Siamese fighting fish (Betta splendens)toward a conspecific, an alien species (Macropodusopercularis), and a mirror image as affected by priorconspecific visual experience.Behav Biol21, 267–72.

39. Robertson CM (1979) Aspects of sexual discriminationby female Siamese fighting fish (Betta splendensRe-gan).Behaviour70, 323–35.

40. Bronstein PM (1985) Predictors of dominance in maleBetta splendens. J Comp Psychol99, 47–55.

41. Oliveira RF, McGregor PK, Latruffe C (1998) Knowthine enemy: fighting fish gather information fromobserving conspecific interactions.Proc Roy Soc LondB 265, 1045–9.

42. Cole B, Tamura CS, Bailey R, Brown C, Ako H (1999)Shipping practices in the ornamental fish industry. Pub-lication No. 131, Center for Tropical and SubtropicalAquaculture, Hawaii.

43. Gomez S, Bernabe A, Gomez MA, Navarro JA,Sanchez (1993) Fish mycobacteriosis: morphopatho-logical and immunocytochemical aspects.J Fish Dis16, 137–41.

44. Lom J, Dykova I, Tonguthai K, Chinabut S (1993)Muscle infection due toHeterosporissp. in the Siamesefighting fish, Betta splendensRegan.J Fish Dis 16,513–6.

45. Puttinaowarat S, Thompson KD, Kolk A, Adams A(2002) Identification ofMycobacteriumspp. isolatedfrom snakehead,Channa striata(Fowler), and Siamesefighting fish, Betta splendens(Regan), using poly-merase chain reaction-reverse cross blot hybridization(PCR-RCBH).J Fish Dis25, 235–43.

46. Lim LC, Dhert P, Sorgeloos P (2003) Recent develop-ments in the application of live feeds in the freshwaterornamental fish culture.Aquaculture227, 319–31.

47. Ratanatham S, Patinawin S (1979) Cytogenetic studies

of Siamese fighting fish (Betta splendensRegan).J SciSoc Thailand5, 17–26.

48. Magtoon W, Rangsiruji A, Donsakul T (2007) Kary-otypes ofBetta splendens, B. prima, Trichopsis vitta-tusandTrichogaster trichopterus(family Belontiidae)from Thailand. In: Proceedings of the 33rd Congresson Science and Technology of Thailand, WalailukUniversity, p 94.

49. Bennington NL (2005) Germ cell origin and spermato-genesis in the Siamese fighting fish,Betta splendens.J Morphol60, 103–25.

50. Jaroensutasinee M, Jaroensutasinee K (2001) Bubblenest habitat characteristics of wild Siamese fightingfish.J Fish Biol58, 1311–9.

51. Jaroensutasinee M, Jaroensutasinee K (2001) Sexualsize dimorphism and male contest in wild Siamesefighting fish.J Fish Biol59, 1614–21.

52. Jaroensutasinee M, Jaroensutasinee K (2003) Type ofintruder and reproductive phase influence male terri-torial defence in wild-caught Siamese fighting fish.Behav Process64, 23–9.

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