Characterization and phylogenetic analysis of the complete mitochondrial genome of Benthodytes gosarsi Gebruk, 2008 (Echinodermata: Holothuroidea: Elasipodida) from deep-sea environments

Deep-sea organisms exhibit remarkable adaptations to extreme environmental conditions. It is important to elucidate the survival mechanisms of deep-sea life by exploring their genetic characteristics and origins. This study reports for the first time the complete mitochondrial genome of a deep-sea holothurian species (Benthodytes gosarsi). The mitochondrial genome of B. gosarsi is 17,133 bp in length and encodes 13 PCGs, 2 rRNAs, and 22 tRNAs. The heavy strand of B. gosarsi mtDNA consists of 31.62% A, 13.30% G, 37.38% T, and 17.70% C bases. Phylogenetic analysis with 18 mitogenomes from five sea cucumber orders determined the phylogenetic position of B. gosarsi within Holothuroidea. This study provides new insights into the genetic structure and phylogenetic relationships of B. gosarsi, contributing to a better understanding of deep-sea adaptation in holothurians.