27 research outputs found
Advances in paediatrics in 2016: current practices and challenges in allergy, autoimmune diseases, cardiology, endocrinology, gastroenterology, infectious diseases, neonatology, nephrology, neurology, nutrition, pulmonology
Racial and Ethnic Disparities in Sudden Unexpected Infant Death and Sudden Infant Death Syndrome Rates in the USA: a Complex Problem Mired in a Deeply Entangled Web
PrevalĂŞncia de infecção por Helicobacter pylori em uma comunidade indĂgena em SĂŁo Paulo e fatores associados: estudo transversal
Geographic differentiation of two Atlanto-Mediterranean species of the genus Xantho (Crustacea: Brachyura: Xanthidae) based on genetic and morphometric analyses
The crab genus Xantho Leach, 1814 is restricted to the northeastern Atlantic Ocean and the Mediterranean Sea. It consists of four species, Xantho hydrophilus (Herbst, 1790), X. poressa (Olivi, 1792), X. pilipes A. Milne-Edwards, 1867, and X. sexdentatus (Miers, 1881). X. hydrophilus has been divided into two geographic forms, of which one, X. h. granulicarpus (Forest, 1953), is postulated to be endemic to the Mediterranean Sea. In this study, we reconstruct phylogenetic relationships of the genus Xantho and related genera from the Atlantic Ocean or Mediterranean Sea and compare different geographic populations of Xantho hydrophilus and, to a lesser extent, of X. poressa by means of population genetic and morphometric analyses. The molecular phylogeny is based on two mitochondrial genes (large subunit rRNA and cytochrome oxidase I) and indicates that X. poressa, X. hydrophilus and X. sexdentatus form a monophyletic group, the latter two species sharing identical haplotypes. On the other hand, X. pilipes shows affinities to Xanthodius denticulatus. Population genetics based on the COI gene reveal genetic differentiation within X. hydrophilus. Morphometric results also give evidence for distinct geographic forms in X. hydrophilus with a clear discrimination. In comparison, morphometric discrimination between different geographic populations of X. poressa is less clear, but still significant. We therefore suggest a recent/ongoing morphological and genetic differentiation within Xantho hydrophilus, restricted gene flow between its Atlantic and Mediterranean populations (not allowing subspecific differentiation) and possible mtDNA introgression between the species X. hydrophilus and X. sexdentatus