Elucidating species diversity of genus Betta from Aceh waters Indonesia using morphometric and genetic data

Abstract

Species of the genus Betta are very similar morphologically which could lead to inaccuracy in taxonomic identification. Therefore, morphological data should also be complemented with other approaches such as genetics to validate the taxonomic status of member species. The objective of this study was to validate the taxonomic status of the genus Betta from Aceh waters using morphometric and genetic data. Sampling was conducted from January to September 2020 at 12 locations within Aceh province. Based on initial assessment identification of morphology, there were four presumed species of Betta in Aceh waters, namely; Betta rubra, Betta dennisyongi, Betta splendens, Betta imbellis. A total of 50 samples from each presumed species were assessed for traditional and truss morphometric analysis, while 5 specimens were randomly selected from each morphospecies for genetic analysis based on the cytochrome oxidase subunit I (COI) gene. The traditional morphometric data divided the four Betta species into two group with B. rubra and B. dennisyongi in same group (group I), while B. splendens and B. imbellis in different group (group II). While, the truss morphometric data divided the four Betta species into three groups with B. rubra and B. dennisyongi in group 1, B. splendens in group 2, while B. imbellis form the other group. The head depth of the fishes was an important characteristic to distinguish members of the four species. In parallel, the genetic analysis supported the occurrence of four valid species with intraspecific values of 0.0–1.59% and interspecific values ranging from 3.3 to 24.7%, the same clustering relationship as in the morphometric data. While B. rubra, B. splendens, and B. imbellis sequences are already available in GenBank, this study reports the first record of B. dennisyongi COI sequences.