This absence of co-occurrence along the contact zone can partiall

This absence of co-occurrence along the contact zone can partially explain the lack of hybridization, raising new interesting questions as to the mechanisms

that Selleck LY2606368 limit sympatry at small spatial scales. “
“The response of Emiliania huxleyi (Lohmann) W. W. Hay et H. Mohler, Calcidiscus leptoporus (G. Murray et V. H. Blackman) J. Schiller, and Syracosphaera pulchra Lohmann to elevated partial pressure of carbon dioxide (pCO2) was investigated in batch cultures. We reported on the response of both haploid and diploid life stages of these three species. Growth rate, cell size, particulate inorganic carbon (PIC), and particulate organic carbon (POC) of both life stages were measured at two different pCO2 (400 and 760 parts per million [ppm]), and their organic and inorganic carbon production were calculated. The two life stages within the same species generally exhibited a similar response to elevated pCO2, the response of the haploid stage being often more pronounced than that of the diploid stage. The growth rate was consistently higher at elevated pCO2, but the response of other processes varied among species. Calcification rate of C. leptoporus and of S. pulchra did not change at elevated

pCO2, whereas it increased in E. huxleyi. POC production BGB324 ic50 and cell size of both life stages of S. pulchra and of the haploid stage of E. huxleyi markedly decreased at elevated pCO2. It remained unaltered in the diploid stage of E. Cyclic nucleotide phosphodiesterase huxleyi and C. leptoporus and increased in the haploid stage of the latter. The PIC:POC ratio increased in E. huxleyi and was constant in C. leptoporus and S. pulchra. Elevated pCO2 has a significant effect on these three coccolithophore species,

the haploid stage being more sensitive. This effect must be taken into account when predicting the fate of coccolithophores in the future ocean. “
“High bulk extracellular phosphatase activity (PA) suggested severe phosphorus (P) deficiency in plankton of three acidified mountain lakes in the Bohemian Forest. Bioavailability of P substantially differed among the lakes due to differences in their P loading, as well as in concentrations of aluminum (Al) and its species, and was accompanied by species-specific responses of phytoplankton. We combined the fluorescently labeled enzyme activity (FLEA) assay with image cytometry to measure cell-specific PA in natural populations of three dinophyte species, occurring in all the lakes throughout May–September 2007. The mean cell-specific PA varied among the lakes within one order of magnitude: 188–1,831 fmol · cell−1 · h−1 for Gymnodinium uberrimum (G. F. Allman) Kof. et Swezy, 21–150 fmol · cell−1 · h−1 for Gymnodinium sp., and 22–365 fmol · cell−1 · h−1 for Peridinium umbonatum F. Stein. To better compare cell-specific PA among the species of different size, the values were normalized per unit of cell biovolume (amol · μm−3 · h−1) for further statistical analysis.

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