The Complete Mitochondrial Genome of the Siberian Scoter Melanitta stejnegeri and Its Phylogenetic Relationship in Anseriformes

The Siberian Scoter (<i>Melanitta stejnegeri</i>) is a medium sea duck distinct from <i>M. deglandi</i> due to the absence of hybridization and differences in morphological characteristics. However, knowledge of its phylogenetic relationships within Anseriformes is limited due to a lack of molecular data. In this study, the complete mitogenome of <i>M. stejnegeri</i> was firstly sequenced, then annotated and used to reconstruct the phylogenetic relationships of 76 Anseriformes species. The complete mitogenome of <i>M. stejnegeri</i> is 16,631 bp and encodes 37 typical genes: 13 protein-coding genes, 2 ribosomal RNAs, 22 transfer RNAs, and 1 non-coding control region. Its mitogenome organization is similar to that of other Anseriformes species. The phylogenetic relationships within the genus <i>Melanitta</i> are initially clarified, with <i>M. americana</i> at the base. <i>M. stejnegeri</i> and <i>M. deglandi</i> are sister groups, clustering with <i>M. fusca</i> and <i>M. perspicillata</i> in order. Phylogenetic analysis suggests that <i>Mareca falcata</i> and <i>M. strepera</i> are sister groups, differing from previous studies. Results firstly indicate that <i>Clangula hyemalis</i> and <i>Somateria mollissima</i> are sister groups, suggesting a potentially skewed phylogenetic relationship may have been overlooked in earlier analyses relying solely on mitochondrial genomes. Our results provide new mitogenome data to support further phylogenetic and taxonomic studies of Anseriformes.