Molecular identification of Ammodytes (PISCES, Ammodytidae) larvae, with ontogenetic evidence on separating populations

A total of ten larval Ammodytes were collected from the Yellow (5 specimens) and Bering Seas (5), and a 638 base pair sequence from their mitochondrial DNA COI genes was analyzed for species identification. Sequences were compared with those of adult Ammodytes personatus from the East (4), the Yellow (2) and the East China Seas (2), and Japan (3). Average genetic distance was 0.064 between the Yellow Sea larvae and the Bering Sea larvae, but was 0.0043 between the Yellow Sea larvae and all the adult A. personatus except two individuals from the East Sea. NJ-tree showed that five Yellow Sea larvae were closely clustered with adult A. personatus, except for two individuals. The five Bering Sea larvae were located distantly from adult A. personatus, and are thought to be A. hexapterus. We found morphological differences among two populations of A. personatus larvae and A. hexapterus larvae in morphometric characters and pigmentation. Our results indicated that the East Sea population of A. personatus is closer to A. hexapterus than to the Yellow Sea population of A. personatus, suggesting the East Sea population may be part of separate species.