Abstract
The complete mitogenome sequence of the milk shark, of which Rhizoprionodon acutus was determined using long PCR. The genome was 16,693 bp in length and it contained 13 protein-coding genes, 2 ribosomal RNA genes, 22 transfer RNA genes, and 1 D-loop region. The overall base composition of the heavy strand is A (31.63%), C (23.91%), T (31.38%), and G (13.08%). However, the base composition of A (31.38%), C (13.08%), T (31.63%), and G (23.91%) was in the light strand. Except for that COXI began with GTG, all the protein initiation codons were ATG. What's more, all the protein termination codons were TAA, in addition to ND2, ND3, and Cytb ended with TAG, COXII and ND4 finished only with T, and ND6 with AGG. Moreover, based on thirteen concatenated PCGs nucleotide datasets, the phylogenetic analysis showed high value support for the following sister clade among the two genera (Rhizoprionodon acutus, Rhizoprionodon; Scoliodon macrorhynchos and Scoliodon laticaudus, Scoliodon).