Complete mitochondrial genome of the largest living fish: whale shark Rhincodon typus (Orectolobiformes: Rhincodontidae)

Abstract

The whale shark Rhincodon typus (Pisces: Chondrichthyes, Orectolobiformes, Rhincodontidae) is the largest living fish on Earth. In this study, we presented its complete mitogenome. It is 16,928 bp in length, contains 13 protein-coding genes, 2 rRNA genes, 22 tRNA genes and one control region with the typical gene order and transcriptional direction in the vertebrates. Overall base composition of the R. typus mitogenome is 33.5% A, 24.3% C, 12.8% G and 29.5% T. Two start codon (GTG and ATG) and two stop codon patterns (TAG and TAA/T) were found in protein-coding genes. The tRNA-Ser2 could not be folded into the typical cloverleaf secondary structure because of the replacement of its dihydrouridine arm by a simple loop. A termination associated sequences (TAS) and three conserved sequence blocks (CSB1-3) were identified in the control region.

• Chondrichthyes
• mitogenome
• whale shark

Declaration of interest

This study was supported by the National Natural Sciences Foundation of China (No. 41006080) and the Major Projects of Basic Research in the Beibu Gulf of Guangxi (No. 2010GXNSFE013002). The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.