Complete mitochondrial genome and the phylogenetic position of the smalleye pygmy shark (Squaliformes: Dalatiidae).

The complete mitogenome of the smalleye pygmy shark (Squaliformes: Dalatiidae) is presented in this study firstly. It is 16,717 bp with a nucleotide base composition of 30.7% A, 26.2% C, 14.7% G and 28.5% T, containing 37 genes and a control region with typical order as vertebrate. There are 23bp short intergenic spaces and 28bp overlaps locating in gene junctions. 2 rRNA genes are located in heavy strand. Twenty-two tRNA genes range from 67bp (tRNA-) to 75 bp (tRNA-1). Two initial codons (ATG and GTG) and two terminal codons (TAA and T) are found in protein-coding genes. The phylogenetic result shows that in this study is clustered to the ( Squalidae).