AbstractBetta mahachaiensis, a new species of fighting fish belonging to the Betta splendens group, is described. The fish inhabitsspecifically sites with brackish water and nipa palms in the Samut Sakhon Province, Thailand. It is distinguishable from othermembers of the B. splendens group in having an iridescent green/bluish-green appearance on the brown-to-black bodybackground. The opercular membrane has brown-to-black colour without red streaks or patches. The opercle has two paralleliridescent green or bluish-green vertical bars. Its dorsal, caudal, and anal fin rays are brown to black, contrasting with theiridescent green or bluish-green of the interradial membrane. Black transverse bars are present on at least the proximal two-thirds of the dorsal fin, but not on the caudal fin. The colour of the pelvic fins is brown to black with an iridescent green/ bluish-green front margin and a white tip. Females possess similar characters but are less colourful than males.
Atchley, W.R. & Anderson, D. (1978) Ratios and the statistical analysis of biological data. Systematic Zoology, 27(1), 71–78.
Cracraft, J. (1989) Speciation and its ontology: the empirical consequences of alternative species concepts for understanding patterns and processes of differentiation. In: Otte, D. & Endler, J.A. (Eds.), Speciation and its Consequences. Sinauer Associates, Sunderland, MA, pp. 28–59.
Dasmahapatra, K.K., Elias, M., Hill, R.I., Hoffman, J.I. & Mallet, J. (2010) Mitochondrial DNA barcoding detects some species that are real, and some that are not. Molecular Ecology Resources, 10(2), 264–273.
Griffin, G. (2005) Bettas in peril: the Mahachai situation. IBC SMP, Species Complex Management Program. Available from http://www.ibcbettas.org/smp/articles/bettas_in_peril_Mahachai_griffin.html (accessed 4 July 2009).
Hebert, P.D.N., Ratnasingham, S. & deWaard, J.R. (2003) Barcoding animal life: cytochrome c oxidase subunit 1 divergences among closely related species. Proceedings of the Royal Society of London, Series B-Biological Sciences, 270, S96–S99.
Hillis, D.M. & Wiens, J.J. (2000) Molecules versus morphology in systematics. Conflicts, artifacts, and misconceptions. In: Wiens, J.J. (ed). Phylogenetic Analysis of Morphological Data. Smithsonian Institution Press. Washington D.C., pp. 1–19.
Krishnamurthy, P.K. & Francis, R.A. (2012) A critical review on the utility of DNA barcoding in biodiversity conservation. Biodiversity and Conservation, 21(8), 1901–1919.
Ladiges, W. (1972) Betta smaragdina nov. spec. Die Aquarien- und Terrarien-Zeitschrift, 25(6), 190–191.
Ladiges, W. (1975) Betta imbellis nov. spec., der Friedliche Kampffisch. Die Aquarien- und Terrarien-Zeitschrift, 28(8), 262–264.
Lertpanich, K. (2007) A study on Mahachai betta an integration of ecological and qualitative research. Proceedings of the International Conference on Integration of Science and Technology for Sustainable Development, Bangkok,Thailand 26-27 April 2007, pp. 296–300.
Lertpanich, K. & Aranyavalai, V. (2007) Species diversity, distribution and habitat characteristics of wild bubble nesting betta (Betta spp.) in Thailand. KMITL Science Journal, 7(1), 37–42.
Lertpanich, K. & Aranyavalai, V. (2010) Morphometry of wild bubble nesting bettas (Betta spp.) in Thailand. Proceedings of the 16th Agricultural Symposium and 1th Symposium on Agricultural Technology "Sufficiency Agriculture", pp. 595–598.
Monvises, A., Nuangsaeng, B., Sriwattanarothai, N. & Panijpan, B. (2009) The Siamese fighting fish: well-known generally but little-known scientifically. ScienceAsia, 35(1), 8–21.
Ng, P.K.L. & Kottelat, M. (1994) Revision of the Betta waseri species group species. (Teleostei: Belontiidae). Raffles Bulletin of Zoology, 42(3), 593–611.
Ng, P. K. L. & Tan, H. M. (1997) Freshwater fishes of Southeast Asia: potential for the aquarium fish trade and conservation issues. Aquarium Sciences and Conservation, 1(2), 79–90.
Nijman, V. (2010) An overview of international wildlife trade from Southeast Asia. Biodiversity Conservation. 19(4), 1101–1114.
Panitvong, N. (2002) Old article resurrection: Betta sp. Mahachai by Nonn, April 2002. Available from http://www.siamensis. org/article/6602 (accessed 31 March 2011).
Ratnasingham, S. & Hebert, P.D.N. (2007) BOLD: The Barcode of Life Data System (http://www.barcodinglife.org). Molecular Ecology Notes, 7(3), 355–364.
Regan, C.T. (1910) The Asiatic fishes of the family Anabantidae. Proceedings of the Zoological Society of London, 1909(pt 4), 767–787, pp. 77–79.
Schindler, I. & Schmidt, J. (2006) Review of the mouthbrooding Betta (Teleostei, Osphronemidae) from Thailand, with descriptions of two new species. Zeitschrift für Fischkunde, 8(1/2), 47–69.
Somadee, S. & Kühne, J. (2012) Saltwater fighting fish or "is it too late for species mahachai?". Labyrinth, Newsletter of the Anabantoid Association of Great Britain, 168, 2–11.
Sriwattanarothai, N., Steinke, D., Ruenwongsa, P., Hanner, R. & Panijpan, B. (2010) Molecular and morphological evidence supports the species status of the Mahachai fighter Betta sp. Mahachai and reveals new species of Betta from Thailand. Journal of Fish Biology, 77(2), 414–424.
Tan, H.H. & Ng, P.K.L. (1996) Redescription of Betta bellica Sauvage, 1884 (Teleostei: Belontidae), with description of a new allied species from Sumatra. Raffles Bulletin of Zoology, 44(1):143–155.
Tan, H.H. & Tan, S.H. (1996) The identity of Betta pugnax (Teleostei: Belontiidae) with the description of a new species of Betta from Malay Peninsula. Raffles Bulletin of Zoology, 44(1), 419–434.
Tan, H.H. & Kottelat, M. (1998) Two new species of Betta (Teleostei: Osphronemidae) from the Kapuas Basin, Kalimantan Barat, Borneo. Raffles Bulletin of Zoology, 46(1): 41–51.
Tan, H. H. & Ng, P.K.L. (2005) The fighting fishes (Teleostei: Osphronemidae: genus Betta) of Singapore, Malaysia and Brunei. Eds. Yeo, D. C. J. & M. Kottelat, Southeast Asian Freshwater Fish Diversity. Raffles Bulletin of Zoology, Supplement no. 13, 43–99.
Tanpitayacoop, C. & Na-Nakorn, U. (2005) Genetic variation of Betta spp. in Thailand by random amplified polymorphic DNA (RAPD) method. Proceedings of the 43rd Kasetsart University Annual Conference, pp. 185–192.
Taylor, H.R. & Harris, W.E. (2012) An emergent science on the brink of irrelevance: a review of the past 8 years of DNA barcoding. Molecular Ecology Resources, 12(3), 377–388.
Vidthayanon, C. (2005) Thailand Red Data: Fishes. ONEP (Resources and Environmental Policy and Planning) biodiversity series volume 16, Integrated Promotion Technology Press. Bangkok, pp. 29.
Witte, K. & Schmidt, J. (1992) Betta brownorum, a new species of anabantoids (Teleostei; Belontiidae) from northwestern Borneo, with a key to the genus. Ichthyological Exploration of Freshwaters, 2(4), 305–330.
Ziegler, A.D., Lim, H.S., Tantasarin, C., Jachowski, N.R. & Wasson, R. (2012) Floods, false hope, and the future. Hydrological Processes, 26(11), 1748–1750.