Identification of chub and spotted mackerels with mitochondrial cytochromeb gene and its application to respective pelagic eggs fixed with formalin

Mitochondrial cytochrome b genes were amplified by PCR using the total DNA as a template from muscle tissues of adult chub mackerel Scomber japonicus and spotted mackerel S. australasicus, and their nucleotide sequences deter mined. The full length of the cytochrome b gene consisted of 1,140 nucleoti des irrespective of the two species, where 16 species-specific Variations w ere observed. Among various restriction enzymes which recognize the cytochr ome b genes from the two fish species, MvaI was specific to the gene of S. japonicus and MboI to that of S. australasicus, with both enzymes producing two fragments. Such species-specific fragmentation patterns were applicabl e to identification of formalin-fixed pelagic eggs from the two species, wh ich was impossible with morphological characteristics.