SPECIES IDENTIFICATION AND MITOCHONDRIAL GENOME SEQUENCING OF FEATHERBACK CHITAL FISH (Chitala chitala)

Abstract

The purpose of this study was to characterize the mitochondrial genome sequencing of Chitala chitala. The complete mitogenome of C. chitala was 16248 bp long and contains 37 mitochondrial genes, including 13 typical protein coding genes, 22 tRNA genes, two ribosomal RNAs (12SrRNA and 16SrRNA), and two non-coding areas (control region, D-loop, and origin of light strand, OL). The heavy (H) strand encoded 28 genes, while the light (L) strand encoded the remaining 9 genes. A total of 31 bp of overlapped area was discovered across the C. chitala mitogenome in 13 distinct places. The mitogenome contained six intergenic spacers totaling 24 bp in length. The longest spacer was an 8-bp nucleotide sequence located between the tRNA and ND1 genes. The 13 protein-coding genes (PCGs) were 11,423 bp in length and accounted for 70.30% of the mitogenome. The base composition was 25.16% T, 29.84% C, 31.4% A, and 13.5% G. C. chitala's circular genome had a short subunit of rRNA (12S rRNA) and a large subunit of rRNA (16S rRNA), both of which were 956 bp and 1702 bp in length, respectively. The 12S rRNA gene had an overall base composition of A = 32.74%, T = 21.75%, C = 25%, and G = 20.50%, while the 16S rRNA gene had an overall base composition of A = 36.13%, T = 19.03%, C = 24.61%, and G = 20.21%. tRNA genes ranged in length from 67 to 76 bp, for a total length of 1,570 bp (9.6% of the total mitogenome). Fourteen tRNA genes were transcribed on the H-strand, while the remaining eight tRNA genes were transcribed on the L-strand. C. chitala's largest non-coding region (control region) consists of 572 nucleotides, accounting for 3.5% of the total mitogenome. The morphologically detected fish species shared 99% of their DNA with C. ornate (Accession No. AP008923.1). Since there is no verified complete mitogenome of Chitala chitala. Currently, it has been considering as a provisional reference sequence (NC_070068.1).