Phylogenetic Variation of <i>Periophthalmus</i> Species Living in the Mekong Delta, Vietnam, Using <i>Cytb</i> Sequence

Mudskippers are amphibious fish that breathe air and have adapted to living on mudflats. They possess unique morphological, physiological, and behavioral features that set them aside from fish that live entirely in water. These characteristics may also have an impact on their phylogenetic and phylogeographical aspects. A study investigated the genetic relationships of mudskippers of the genus <i>Periophthalmus</i> found in four mudflat areas in the Mekong Delta. The outcomes of the <i>Cytb</i> phylogenetic tree analysis of the genus <i>Periophthalmus</i> revealed that the three species of <i>Periophthalmus</i>, namely <i>Periophthalmus chrysospilos</i>, <i>Periophthalmus gracilis</i>, and <i>Periophthalmus variabilis</i>, separated into three sub-clades. The sub-clades showed a high degree of genetic divergence and were supported by a bootstrap value of 100%. Thus, the <i>Cytb</i> gene analysis technique helped to reconstruct the genetic relationship of these three mudskipper species of the genus <i>Periophthalmus</i>. This study provided an essential understanding of the evolutionary history of mudskippers and shed light on the phylogenetic and phylogeographical characteristics of this unique group of amphibious fish.