Amplified fragment length polymorphism analysis of the mesopelagic copepod Disseta palumbii in the equatorial western Pacific and adjacent waters: Role of marginal seas in the genetic isolation of mesopelagic animals

The genetic structure of the mesopelagic copepod Disseta palumbii in the equatorial western Pacific and adjacent marginal seas was examined by the amplified fragment length polymorphism (AFLP) analysis of 34 individuals from the Philippine Sea (10 individuals), Celebes Sea (10), Sulu Sea (4), and South China Sea (10). Phylogenetic analysis of the scored AFLP results showed two major clades (clades A and B) with six and sixteen alleles that were uniquely observed in clade A and B, respectively. Within clade B, subtle but significant genetic differences between individuals in the Sulu and those in the other seas were also observed, suggesting a role for semienclosed marginal seas in allopatric speciation.