Resumen de An Investigation of the Global Population Structure of the Marlinsucker (Remora Osteochir) Inferred from Mitochondrial Control Region DNA Sequence Analysis
Kurtis N. Gray, Jan R. McDowell, Bruce B. Collette, John E Graves
Nucleotide sequences from the hypervariable mitochondrial control region were used to investigate phylogeographic structuring in the marlinsucker, Remora osteochir (Cuvier, 1829). Complete DNA sequences were isolated from 71 individuals collected from seven geographically distant sample locations (5 Atlantic and 2 Pacific). Analyses of molecular variance (AMOVA) and ?st resolved significant levels of population structuring among collections from the Atlantic and Pacific oceans, whereas negligible levels of population structuring were resolved among collections from within the Atlantic or Pacific oceans. Cluster analysis of haplotypes based upon inter-haplotype divergences resolved two distinct evolutionary lineages, one composed of haplotypes that only occurred in the Atlantic, and one composed of haplotypes that occurred in both Atlantic and Pacific samples. Observations are consistent with vicariant isolation of Atlantic and Pacific marlinsucker, followed by geologically recent secondary colonization of the Atlantic from the Indian Ocean. Congruence between patterns of genetic differentiation between marlinsucker and their istiophorid hosts, particularly blue marlin, Makaira nigricans Lacépède, 1802, and sailfish, Istiophorus platypterus (Shaw, 1792), highlights the possibility that this symbiont's phylogeography is ultimately governed by host dispersal.
