title: Phylogeography and population genetics of the endangered Amazonian manatee, Trichechus inunguis Natterer, 1883 (Mammalia, Sirenia).
abstract: We used mitochondrial DNA control region sequences to examine phylogeography and population differentiation of the endangered Amazonian manatee Trichechus inunguis. We observe lack of molecular differentiation among localities and we find weak association between geographical and genetic distances. However, nested clade analysis supports restricted gene flow and/or dispersal with some long-distance dispersal. Although this species has a history of extensive hunting, genetic diversity and effective population sizes are relatively high when compared to the West Indian manatee Trichechus manatus. Patterns of mtDNA haplotype diversity in T. inunguis suggest a genetic disequilibrium most likely explained by demographic expansion resulting from secession of hunting and enforcement of conservation and protective measures. Phylogenetic analysis of T. manatus and T. inunguis haplotypes suggests that T. inunguis is nested within T. manatus, effectively making T. manatus a paraphyletic entity. Paraphyly of T. manatus and recent divergence times of T. inunguis and the three main T. manatus lineages suggest a possible need for a taxonomic re-evaluation of the western Atlantic Trichechus.
authors.affiliation: Laboratório de Mamíferos Aquáticos - CPBA - INPA, Manaus, Amazonas, Brazil. manatee@inpa.gov.br
authors.forename: Andréa Martins
authors.initials: AM
authors.lastname: Cantanhede
authors.forename: Vera Maria Ferreira
authors.initials: VM
authors.lastname: Da Silva
authors.forename: Izeni Pires
authors.initials: IP
authors.lastname: Farias
authors.forename: Tomas
authors.initials: T
authors.lastname: Hrbek
authors.forename: Stella Maris
authors.initials: SM
authors.lastname: Lazzarini
authors.forename: José
authors.initials: J
authors.lastname: Alves-Gomes
mesh_terms: D000818:Animals; D001483:Base Sequence; D017931:DNA Primers; D004272:DNA, Mitochondrial / Q000235:genetics; D003710:Demography; D014644:Genetic Variation; D005828:Genetics, Population; D005843:Geography; D006239:Haplotypes / Q000235:genetics; D016013:Likelihood Functions; D008957:Models, Genetic; D008969:Molecular Sequence Data; D010802:Phylogeny; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D020456:Trichechus inunguis / Q000235:genetics*
chemical_list: D017931:DNA Primers; D004272:DNA, Mitochondrial