Genetic connectivity of sea urchin Tripneustes gratilla in Teluk Cenderawasih, Papua-Indonesia

Abstract

This study was conducted to determine the genetic connectivity of Tripneustes gratilla based on the mitochondrial cytochrome c oxidase 1 gene (COI mtDNA). A total of 76 T. gratilla samples were collected from Biak, Manokwari, Yapen, Nabire, and Wasior in Cenderawasih Bay of Papua. We used genetcs approach to infer dispersal and diversity pattern among all populations of the sea urchin, T. gratilla. Our analyses produced three major results concerning the genetic connectivity of T. gratilla. First, haplotype diversity was high in all populations (0.82) and nucleotide diversity was low for all samples (0.0027). There are common haplotypes at all individual and shared by individual for all populations. Second, no significant in source of variation to the total sequence divergences in T. gratilla. Fixation indices of F-statistics values indicated no genetic differentiation. Fst values was indicated no significan difference in each pairwise combination of these 5 populations except the Yapen with Manokwari and Nabire populations. Third, mismatch distributions of COI haplotypes reflects that many pairs of individuals differs by just less than 2 units of mutational time. Results from neighbor-joining tree analysis of the COI sequences of T. gratilla showed that all individual in Cenderawasih Bay has close connectivity each other. The gene flow between Cenderawasih Bay populations was high.