Phylogenetic Analysis and Genetic Diversity Among Some Red Sea Reef Fishes (Perciformes: Labridae) Based on Partial 16S Mitochondrial Gene Sequences

This study investigated the sequence variation and phylogenetic relationships among 14 labrid fish species (Family: Labridae) from the coral reefs of Hurghada, the Red Sea, Egypt, using a fragment of the 16S mitochondrial gene (16S mt-rDNA). Comparison with similar species from the GenBank/NCBI published sequences was conducted. Sequencing analysis and phylogenetic tree construction employed maximum likelihood, neighbor-joining, and maximum parsimony methods. The results demonstrated the efficiency of 16S mt-rDNA in illustrating the genetic variation, indicating close genetic relations and shared ancestry among the studied genus and species, viz.  Epibulus with Cheilinus andgenus Gomphosus with Thalassoma. The phylogenetic hypotheses (ML, NJ and MP) produced similar topologies with slight differences in the bootstrap support values. Two main lineages, cheilines and julidines, each containing clades of genera, revealed a monophyletic group of labrid species. Distinct clades and clusters among genera highlighted evolutionary relationships within the Labridae family. The 16S gene effectively elucidates genetic diversity and phylogenetic patterns, underscoring its utility as a molecular marker for reef fish phylogenetic studies. The development of such molecular markers helps detect biodiversity and understand molecular phylogenetic relationships in this important aquatic biological resource.