DNA barcode and evolutionary relationship within Laemolyta Cope 1872 (Characiformes: Anostomidae) through molecular analyses

- DNA barcode was useful for identify all lineages.
- Two new lineages were found in the genus.
- Two clades associated to the body color pattern were recovered.
- Clade A joined fishes with no vertical bars and clade B fishes with vertical bars.

The Laemolyta genus is a monophyletic group with five valid species. Phylogenetic relationships among the species of this genus are unknown. We analyzed four nominal Laemolyta species. The COI gene for all individuals was amplified and the genetic distances were estimated. We performed genetic distance analyses to determine the different MOTUs. Two mitochondrial (COI and CytB) and three nuclear (Myh6, RAG1 and RAG2) markers were amplified for one individual of each identified MOTU. Maximum Parsimony and Maximum Likelihood were conducted using concatenate alignment. In addition, multilocus Bayesian species tree was carried out. By using DNA barcode, we identified six different MOTUs. The COI inter-MOTU distances ranged from 0.92% to 5.76%. The normalized mean intra-MOTU distance was 0.13%. The DNA barcode was useful to diagnose all species. Two clades showing distinct color patterns were recovered in all molecular phylogenetic trees. Clade A joined fishes with no vertical bars (L. garmani, L. taeniata 1 and L. taeniata 2) and clade B, fishes with vertical dark bars (L. fernandezi Araguaia, L. fernandezi Xingu, and L. proxima). The results were able to identify the cryptic biodiversity within the group and obtained the most complete Laemolyta phylogeny.