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

## TL;DR

This study sequenced the complete mitochondrial genome of the Siberian Scoter and used it to clarify its evolutionary relationships within the Anseriformes order.

## Contribution

The first complete mitogenome of Melanitta stejnegeri and new insights into the phylogenetic relationships of Anseriformes species.

## Key findings

- The Siberian Scoter's mitogenome is 16,631 bp and contains 37 typical mitochondrial genes.
- M. stejnegeri and M. deglandi are sister groups, clustering with M. fusca and M. perspicillata.
- Clangula hyemalis and Somateria mollissima are sister groups, suggesting a previously overlooked relationship.

## Abstract

The Siberian Scoter (Melanitta stejnegeri) is a medium sea duck distinct from M. deglandi 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 M. stejnegeri was firstly sequenced, then annotated and used to reconstruct the phylogenetic relationships of 76 Anseriformes species. The complete mitogenome of M. stejnegeri 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 Melanitta are initially clarified, with M. americana at the base. M. stejnegeri and M. deglandi are sister groups, clustering with M. fusca and M. perspicillata in order. Phylogenetic analysis suggests that Mareca falcata and M. strepera are sister groups, differing from previous studies. Results firstly indicate that Clangula hyemalis and Somateria mollissima 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.