High Variability in Cellular Stoichiometry of Carbon, Nitrogen, and Phosphorus Within Classes of Marine Eukaryotic Phytoplankton Under Sufficient Nutrient Conditions

Abstract

Current hypotheses suggest that cellular elemental stoichiometry of marine eukaryotic phytoplankton such as the ratios of cellular carbon:nitrogen:phosphorus (C:N:P) vary between phylogenetic groups. To investigate how phylogenetic structure, cell volume, growth rate, and temperature interact to affect the cellular elemental stoichiometry of marine eukaryotic phytoplankton, we examined the C:N:P composition in 30 isolates across 7 classes of marine phytoplankton that were grown with a sufficient supply of nutrients and nitrate as the nitrogen source. The isolates covered a wide range in cell volume (5 orders of magnitude), growth rate (<0.01–0.9 d−1), and habitat temperature (2–24°C). Our analysis indicates that C:N:P is highly variable, with statistical model residuals accounting for over half of the total variance and no relationship between phylogeny and elemental stoichiometry. Furthermore, our data indicated that variability in C:P, N:P, and C:N within Bacillariophyceae (diatoms) was as high as that among all of the isolates that we examined. In addition, a linear statistical model identified a positive relationship between diatom cell volume and C:P and N:P. Among all of the isolates that we examined, the statistical model identified temperature as a significant factor, consistent with the temperature-dependent translation efficiency model, but temperature only explained 5% of the total statistical model variance. While some of our results support data from previous field studies, the high variability of elemental ratios within Bacillariophyceae contradicts previous work that suggests that this cosmopolitan group of microalgae has consistently low C:P and N:P ratios in comparison with other groups.

Intraspecific trait variation and trade‐offs within and across populations of a toxic dinoflagellate

“…S5). This is presumably caused by the vast range in cell size across species, that affects growth rate, nitrogen acquisition and elemental composition Edwards et al 2015a, b;Garcia et al 2018). The intraspecific variation in K 1/2 values for nitrogen, however, was comparable to the earlier reported interspecific variation across marine phytoplankton species (Fig.…”

“…; Edwards et al . , b; Garcia et al ). The intraspecific variation in K 1/2 values for nitrogen, however, was comparable to the earlier reported interspecific variation across marine phytoplankton species (Fig.…”

Growth and Elemental Stoichiometry of the Ecologically-Relevant Arctic Diatom Chaetoceros gelidus: A Mix of Polar and Temperate

“…The C:N ratios observed here for C. gelidus at 0 • C (7.48 ± 0.83 mol C mol −1 N) are at the upper bound of values reported for other polar diatoms by Lacour et al (2017) in the -0.5 to 5 • C Levasseur et al, 1993 temperature range (average = 5.77 ± 0.52 mol C mol −1 N), by Garcia et al (2018) at 2 • C (average = 6.09 ± 0.59 mol C mol −1 N, range 5.72-6.97), and at 2 • C [average = 5.99 ± 0.99 mol C mol −1 N, range 5.01-7.51; calculated using the dataset of , for cells in exponential growth phase]. However, the C:N ratio of C. gelidus is remarkably close to the average reported by Sarthou et al (2005) for temperate diatoms (7.3 ± 1.2 mol C mol −1 N, range 5.0 to 9.7 mol C mol −1 N) and suggests that this species is able to incorporate more C per unit N in its biomass than most other Arctic diatoms.…”

High single‐cell diversity in carbon and nitrogen assimilations by a chain‐forming diatom across a century

“…These resting stages can survive for at least a century in the sediment, and upon revival, we can study adaptations to eutrophication within local Skeletonema populations (McQuoid et al, 2002;Härnström et al, 2011;Ellegaard et al, 2018). A recent study demonstrated higher variability of diatoms in carbon, nitrogen and phosphorus quota on a clone specific level compared to other phytoplankton (Garcia et al, 2018). We hypothesized that a diversity of nutrient demands occurs even at a single-cell level in diatoms including Skeletonema.…”

“…This relationship led to the theory of a fixed stoichiometric ratio between carbon, nitrogen and phosphorus (106:16:1) in phytoplankton based on the ratio at which the nutrients are consumed by phytoplankton during growth (Redfield, 1934;1958). Throughout the last decades, this concept has been reconsidered based on culture studies indicating large variations in organic matter nutrient ratios, associated to nutrient availability, light and temperature (Geider and LaRoche, 2002;Gruber and Deutch, 2014;Garcia et al, 2018). Since the introduction of fertilizers within the agroindustry during the last century, concentrations of nitrate, particularly in coastal areas, have increased.…”