Complete Mitochondrial Genomes and Phylogenetic Analysis of Genus (Asteroidea: Spinulosida: Echinasteridae).

The genus is known to have intraspecific morphological variations, making species identification difficult. Therefore, molecular phylogeny analysis based on genetic characteristics is valuable for species identification. We present complete mitochondrial genomic sequences of , , and for the first time in this study. This study will make a significant contribution to our understanding of species and its relationships within the class Asteroidea. Lengths of mitochondrial genomes of the three species are 16,217, 16,223, and 16,194 bp, respectively, with a circular form. These genomes contained 13 protein-coding genes, two ribosomal RNA genes, 22 transfer RNA genes, and a D-loop. The gene order and direction aligned with other asteroid species. Phylogenetic relationship analysis showed that our species were in a monophyletic clade with other species and in a large clade with species () from the same family. These findings provide valuable insight into understanding the phylogenetic relationships of species in the genus .