Molecular Phylogeny of Rasboroides (Family Cyprinidae): An Endemic Freshwater Fish Species in Sri Lanka

Abstract

Fish are considered as a highly diverse paraphyletic group in the animal kingdom. Freshwater fish show a significant diversity. The family Cyprinidae consists of the largest freshwater fish group, including nearly 210 genera and 2,100 species which exhibit a vast distribution throughout the world. Among the freshwater fishes, Rasbora is considered as the most species rich genus within the subfamily Rasboroinae. Rasboroides is endemic to Sri Lanka and represents four species, including Rasboroides vaterifloris, Rasboroides nigromarginatus,Rasboroides pallidus and Rasboroides rohani. According to morphological studies, these species are grouped into one genus, but molecular identification has not been carried out except for Rasboroides vaterifloris. This study was designed to understand the position of Rasboroides vaterifloris within the family Cyprinidae. The mitochondrial cytochrome oxidase C gene (Cox1) sequences of 40 taxa were extracted from the National Center for Biotechnology Information (NCBI). A phylogenetic analysis carried out using the parsimony method in Seaview 4.6.1 with 1000 bootstrapped. The resulting phylogeny comprised of six main clades. Horadandia atukorali, and Rasboroides vaterifloris in the current study showed the sister group relationship with Rasbora trilineata and showed a monophyletic relationship with clade B. The sister group of Rasboroides vaterifloris and Horadandia atukorali showed a monophyletic relationship with Rasbora trilineata with a low bootstrap (46%). These results support the findings of the recent studies of Genus Rasboroides. It is essential to study more species in order to identify the taxonomical location of Rasboroides vaterifloris in the Family Cypirinidae