MITOCHONDRIAL-DNA DIFFERENTIATION BETWEEN 2 SYMPATRIC MORPHS OF STRIPED JACK NEAR JAPAN

Two sympatric morphs (type A with a vertebral number of 25 and type B with a vertebral number of 24) of striped jack Pseudocaranx dentex (Bl och & Schneider) were analysed genetically. A part of the 16S-rRNA reg ion of mtDNA was amplified with polymerase chain reaction for 24 speci mens, and a restriction enzyme fragment polymorphism showed significan t differences between the two types. While all specimens sampled in Og asawara were identified as type B, about 90% of striped jack in Oita w ere type A and 10% were type B. Although the spawning areas of these t wo types are still unknown, significant genetic differences between th e two sympatric morphs show that recruitment and migration patterns mi ght differ from each other. The current system suggests the possibilit y that the juveniles of type B in Oita may migrate from the Ogasawara Islands.