Molecular and morphological evidence supports the species status of the Mahachai fighter Betta sp. Mahachai and reveals new species of Betta from Thailand

• Published in: Journal of fish biology 2010-08, Vol.77 (2), p.414-424
• Main Authors: Sriwattanarothai, N., Steinke, D., Ruenwongsa, P., Hanner, R., Panijpan, B.
• Format: Article
• Language: English
• Subjects: 16S rRNA; Animals; Bayes Theorem; Betta; Betta smaragdina; Betta smaragdina var; Betta sp. Mahachai; Betta splendens complex; cytochrome c oxidase subunit 1; DNA barcoding; DNA, Mitochondrial - genetics; Electron Transport Complex IV - genetics; Evolution, Molecular; Indonesia; Likelihood Functions; Perciformes - anatomy & histology; Perciformes - classification; Perciformes - genetics; Phylogeny; RNA, Ribosomal, 16S - genetics; Sequence Analysis, DNA; Thailand
• ISSN: 0022-1112; 1095-8649
• DOI: 10.1111/j.1095-8649.2010.02715.x

Two regions of mitochondrial (mt) DNA, cytochrome c oxidase subunit 1 (COI) and 16S rRNA, were sequenced in nine species of Betta from Thailand and Indonesia. Most species showed little intraspecific COI variation (adjusted mean = 0·48%) including the putative species Betta sp. Mahachai, but one species (Betta smaragdina) included three lineages showing much greater divergence (7·03–13·48%) that probably represent overlooked species. These findings were confirmed by maximum likelihood analysis and Bayesian inference, which revealed well‐supported corresponding monophyletic clades. Based on these results and morphological differences, the putative species Betta sp. Mahachai from central Thailand is a species distinct from other members of the B. splendens group and represents a new and hitherto undescribed species. Furthermore, this study also demonstrated the probable existence of two overlooked Betta species found in the Khorat plateau basin, illustrating the utility of mitochondrial genetic markers in the revelation of overlooked diversity.