The evoluationary history of rabbitfish (siganidae) based on morphological and molecular data

Abstract

A total of 18 nominal species in genus Siganus (Siganidae) is classified based on morphological features and colouration patterns. The remarkable morphological similarities and the intermediate morphological characters resulted in taxonomic confusion in Siganidae. Although a series of phylogenetic studies have been conducted, the research on divergence time and evolutionary history of rabbitfish are still lacking. This study was conducted to 1) determine the morphological characteristics of Siganus species collected from Terengganu Waters 2) show the patterns of phylogenetic diversification of siganids and 3) infer the time of divergence of the species by using the time-calibrated phylogeny. The phylogenetic tree of Siganus species was reconstructed based on mitochondrial DNA sequences of cytochrome oxidase I (COI) and nuclear DNA sequences of rhodopsin retrogene. The results were compared with morphological analysis outcomes. The Bayesian Inference (BI) and Neighbour-Joining (NJ) analyses of both genes produced phylogeny structure that are not identical due to the inconsistent placement of S. argenteus.