Search results for "Echinocardium cordatum"
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Morphological and genetic analyses reveal a cryptic species complex in the echinoid Echinocardium cordatum and rule out a stabilizing selection expla…
2014
14 pages; International audience; Preliminary analyses revealed the presence of at least five mitochondrial clades within the widespread sea urchin Echinocardium cordatum (Spatangoida). In this study, we analyzed the genetic (two mitochondrial and two nuclear sequence loci) and morphological characteristics (20 indices) from worldwide samples of this taxon to establish the species limits, morphological diversity and differentiation. Co-occurring spatangoid species were also analyzed with mitochondrial DNA. The nuclear sequences confirm that mitochondrial lineages correspond to true genetic entities and reveal that two clades (named A and B1) hybridize in their sympatry area, although a more…
L'ontogenèse complexe du spatangue Echinocardium cordatum: Un test des standards des trajectoires hétérochroniques
1991
The growth of the spatangoid echinoid Echinocardium cordatum is described by using the three standards (size,shape and age) that are classicaly involved in analyses of heterochronies. A population from Normandy, including all the growth stages, allows an ontogenetic reference to be established, while comparisons are performed with adult samples from other localities (Brittany, Aquitaine, and New-Zealand). The morphology of E. cordatum is characterized by 23 measured parameters and 13 calculated indexes. The ontogenetic trajectory of the species is depicted from the measurements of the size increments, from the analysis of the shape changes, and from an estimate of age. An estimate of the ag…