Characterization and phylogenetic analysis of the complete mitochondrial genome of a tropical sea cucumber,Holothuria fuscocinerea

In this study, the mitochondrial genome (mitogenome) ofHolothuria fuscocinereawas unraveled to be 15,890 bp in length, containing 13 protein-coding genes (PCGs), 22 tRNA genes, and 2 rRNA genes. The PCGs were initiated by four initiation codons (ATG, TAC, ATC, and ATA). Only one PCG (nad6) and five tRNA genes (tRNA(Ser(UCN)),tRNA(Gln),tRNA(Ala),tRNA(Val),andtRNA(Asp)) were encoded on the light chain, and the other genes were encoded on the heavy chain. A phylogenetic tree constructed with 16S rRNA sequences showed thatH. fuscocinereais most closely related toH. leucospilota.