3.3.3 Order Siluriformes
A total of 14 samples were sequenced belonging to four families, six genera and six species. The overall mean nucleotide base frequencies observed for these sequences were—T: 29.30%, C: 28.10%, A: 24.80% and G: 17.70%. The AT content (54.10%) was higher than the GC content (45.90%). The GC contents at the first, second and third codon positions were 56.70%, 42.70% and 38.10% respectively. The K2P distances of the COI sequence within species and between species were 0.14 and 26.62 respectively.