%0 Journal Article %J Protist %D 2011 %T Integrative taxonomy of the pavlovophyceae (haptophyta) : a reassessment %A Bendif, E M %A Probert, I %A Hervé, A %A Billard, C %A Goux, D %A Lelong, C %A Cadoret, J P %A Véron, B %K 2011 %K ASSEMBLE %K rcc %K RCC1523 %K rcc1524 %K rcc1525 %K RCC1526 %K RCC1527 %K RCC1528 %K RCC1529 %K RCC1530 %K RCC1531 %K RCC1532 %K RCC1533 %K RCC1534 %K RCC1535 %K RCC1536 %K RCC1537 %K RCC1538 %K RCC1539 %K RCC1540 %K RCC1541 %K RCC1542 %K RCC1543 %K RCC1544 %K RCC1545 %K RCC1546 %K RCC1548 %K RCC1549 %K RCC1551 %K RCC1552 %K RCC1553 %K RCC1554 %K RCC1557 %K SBR$_\textrmP$hyto$_\textrmE$PPO %X The Pavlovophyceae (Haptophyta) contains four genera (Pavlova, Diacronema, Exanthemachrysis and Rebecca) and only thirteen characterised species. Considering the importance of members of this class, we constructed molecular phylogenies inferred from sequencing of ribosomal gene markers with comprehensive coverage of the described diversity and using type strains when available add on culture strains. Moreover, the morphology and ultrastructure of 12 of the described species was re-examined and the pigment signatures of many culture strains were determined. The molecular analysis revealed that sequences of all described species differed, although those of Pavlova gyrans and P. pinguis were nearly identical, these potentially forming a single cryptic species complex. Four well-delineated genetic clades were identified, one of which included species of both Pavlova andDiacronema. Unique combinations of morphological/ultrastructural characters were identified foreach of these clades. The ancestral pigment signature of the Pavlovophyceae consisted of a basic set of pigments plus MV chl cPAV, the latter being entirely absent in the Pavlova + Diacronema clade and supplemented by DV chl cPAV in part of the Exanthemachrysis clade. Based on this combination of characters, we propose a taxonomic revision of the class, with transfer of several Pavlova species to an emended Diacronema genus. The evolution of the class is discussed in the context of the phylogenetic reconstruction presented. %B Protist %V 162 %P 738–761 %G eng %R 10.1016/j.protis.2011.05.001 %0 Journal Article %J Nature %D 2011 %T Sensitivity of coccolithophores to carbonate chemistry and ocean acidification %A Beaufort, L %A Probert, I %A de Garidel-Thoron, T %A Bendif, E M %A Ruiz-Pino, D %A Metzl, N %A Goyet, C %A Buchet, N %A Coupel, P %A Grelaud, M %A Rost, B %A Rickaby, R E M %A de Vargas, C %K 2011 %K rcc %K SBR$_\textrmP$hyto$_\textrmE$PPO %K sbr?hyto?ppo %X Coccolithophores produce the major fraction of pelagic carbonate, a key component of the carbon cycle. The effect of elevated CO2 on their calcification is poorly understood. Culture experiments have yielded varied calcification responses to increased pCO2 between and within coccolithophore taxa. We used a novel automated method for pattern recognition and morphometric analysis to quantify the calcite mass of coccolithophores from ¿700 samples from present past (last 40-Kyr) oceans. Comparison of morphological data with ocean carbonate chemistry reconstructed in both space and time indicate decreasing calcification with increasing pCO2, and decreasing CO32. At pH ¡8.0, delicate Emiliania huxleyi are strongly affected by decalcification. However, highly calcified E. huxleyi morphotypes predominate in waters with lowest pH. This suggests that coccolithophore strains pre-adapted to future, more acidic oceans already populate regions of contemporary oceans. The future carbon feedback from coccolithophore calcification will depend on the genetic diversity and adaptability of coccolithophore populations. %B Nature %V 476 %P 80–83 %G eng %R 10.1038/nature10295