Molecular identification of Epixanthus frontalis (Brachyuran: Oziinae) from the rocky shores of Bushehr province using DNA barcode method

Epixanthus frontalis is the only known species of the genus Epixanthus from the Persian Gulf which include color polymorphic specimens. Considering that cryptic species are common among crustaceans, the aim of this study was to identify the cryptic species complexes the collected samples from the Persian Gulf. For this purpose, 4 colorful morphotypes of E. frontalis collected from rocky shores along Bushehr province. Then the first male gonopods was separated and photographed by scanning electron microscopy (SEM). For molecular studies samples of DNA extracted by using phenol-chloroform and mitochondrial cytochrome oxidase subunit gene segment (COI) was PCR and sequenced. The results showed that the nucleotide sequence of this gene fragment of the mitochondrial (COI) is not identical in all colorful morphotypes. These results reflected in the evolution of tree topology for all two analyses (maximum likelihood, bayesian). The study of apical ultrastructure segments of the first male species showed that it can be seen fundamental differences in the apical organs in some colorful morphotypes. Results of this study indicated that although the specimens assigned to single species morphologically, they may belong to different species based on their genotype. Further molecular studies with specific markers are needed for molecular identifications.