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Cunha, Regina L.; Blanc, Francoise; Bonhomme, Francois; Arnaud-haond, Sophie. |
Pearl oysters belonging to the genus Pinctada (Bivalvia: Pteriidae) are widely distributed between the Indo-Pacific and western Atlantic. The existence of both widely distributed and more restricted species makes this group a suitable model to study diversification patterns and prevailing modes of speciation. Phylogenies of eight out of the 11 currently recognised Pinctada species using mitochondrial (cox1) and nuclear (18S rRNA) data yielded two monophyletic groups that correspond to shell size and presence/absence of hinge teeth. Character trace of these morphological characters onto the molecular phylogeny revealed a strong correlation. Pinctada margaritifera appears polyphyletic with specimens from Mauritius grouping in a different clade from others of... |
Tipo: Text |
Palavras-chave: Pinctada; Evolutionary patterns; Species complex; Allopatry; Biogeography. |
Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00035/14635/14015.pdf |
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Teixeira,Simone P.; Ranga,Neusa T.. |
Dahlstedtia has been considered a monotypic genus by some authors, but comprising two species according to others. The latter view was supported by our biosystematic study. The two species are Neotropical, mainly occurring in the Brazilian Atlantic Forest, where they are, however, allopatric. Experimental pollinations show that the two species are intersterile. After interspecificcrossings, few pollen tubes reach the ovule, a dense secretion fills the micropyle and no proembryos are formed. Probably, there is no gene flow between species, but if it should occur, no hybrids would be formed. The present work confirms Burkart's taxonomic view, according to which Dahlstedtia comprises at least two species: D. pinnata and D. pentaphylla. |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Allopatry; Dahlstedtia pentaphylla; Dahlstedtia pinnata; Gene flow; Geographical distribution. |
Ano: 2004 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-84042004000100005 |
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