RESUMO
Populations of the marine benthic red macroalgae Hypnea musciformis and Hypnea pseudomusciformis along the Atlantic and Pacific Oceans were tested for phylogeographic structure using the DNA barcode COI-5P combined with rbcL for the construction of the phylogenetic tree. Strong patterns of genetic structure were detected across 210 COI-5P DNA sequences, and 37 COI-5P haplotypes were found, using multiple statistical approaches. Hypnea musciformis was found in the Northeast and Northwest Atlantic, the Mediterrean Sea, Namibia, and along the Pacific coast of Mexico. Two new putative species were detected, Hypnea sp. 1 in the Caribbean Sea and Hypnea sp. 2 in the Dominican Republic. Three distinct marine phylogeographic provinces were recognized in the Southern Hemisphere for H. pseudomusciformis: Uruguay, South-Southeast Brazil, and Northeast Brazil. The degree of genetic isolation and distinctness among these provinces varied considerably. The Uruguay province was the most genetically distinct, as characterized by four unique haplotypes not shared with any of the Brazilian populations. Statistically significant results support both, isolation by distance and isolation by environment hypotheses, explaining the formation and mantainance of phylogeographic structuring along the Uruguay-Brazil coast. Geographic, taxonomic and molecular marker concordances were found between our H. pseudomusciformis results and published studies. Furthermore, our data indicate that the Hawaiian introduced populations of H. musciformis contain Hypnea sp. 1 haplotypes, the current known distribution of which is restricted to the Caribbean.
Assuntos
Rodófitas , Oceano Atlântico , Brasil , Região do Caribe , DNA Mitocondrial , Variação Genética , Haplótipos , Havaí , México , Oceano Pacífico , Filogenia , Filogeografia , Análise de Sequência de DNARESUMO
As espécies indicadoras de poluiçäo hídrica säo resistentes. A poluiçäo tem vários graus de intensidade, dependendo da diluiçäo do poluente no ambiente, fenômenos de antagonismo, sinergismo, grau de toxidade, etc, afetando a diversidade e a estabilidade dos organismos aquáticos. Para caracterizar zonas de poluiçäo säo usados grupos de organismos aquáticos do zoo e fitoplâncton. No Brasil, para as algas, há dificuldades por causa da falta de especialistas e recursos para a ciência taxonômica. Este trabalho faz levantamento histórico e recomenda a criaçäo de Centro Nacional de Taxonomia, para intercambiar informaçöes e facilitar o uso de algas como indicadores de poluiçäo