Complete mitochondrial genome of the Yellownose skate: Zearaja chilensis (Rajiformes, Rajidae).

The complete sequence of mitochondrial DNA of a Yellownose skate, Zearaja chilensis was determined for the first time. It is 16,909 bp in length covering 2 rRNA, 22 tRNA and 13 protein coding genes with the identical gene order and structure as those of other Rajidae species. The nucleotide of L-strand is composed of low G (14.3%), and slightly high A + T (58.9%) nucleotides. The strong codon usage bias against the use of G (6.0%) is found at the third codon positions. Twelve of the 13 protein coding genes use ATG as the start codon while COX1 starts with GTG. As for the stop codon, only ND4 shows an incomplete stop codon TA. This is the first report of the mitogenome for a species in the genus Zearaja, providing a valuable source of genetic information on the evolution of the family Rajidae and the genus Zearaja as well as for establishment of a sustainble fishery management plan of the species.

Complete mitochondrial genome of Chilean sea urchin: Loxechinus albus (Camarodonta, Parechinidae).

The complete mitochondrial genome of Chilean sea urchin Loxechinus albus, the single species of the genus Loxechinus, is determined. The circular mitogenome is 15,709 bp in length containing 2 rRNA, 22 tRNA and 13 protein coding genes as well as the control region. The gene order is identical to those of described Camarodonta species. There are 24 bp gene overlaps at 6 locations and 124 bp intergenic spacers at 17 boundaries. The nucleotide composition of the genome is 31.2% A, 22.3% C, 29.7% T, and 16.8% G. The A+T bias (60.9%) is similar to that of P. lividus (60.3%) but slightly higher than those of strongylocentrotid species (58.8-59.8%). The mitogenome sequence of L. albus will provide valuable information on the phylogeny and evolution of the genus Loxechinus in relation to other Camarodonta sea urchins.