scholarly journals Interactive effect of warming, nitrogen and phosphorus limitation on phytoplankton cell size

2015 ◽  
Vol 5 (5) ◽  
pp. 1011-1024 ◽  
Author(s):  
Kalista Higini Peter ◽  
Ulrich Sommer
Keyword(s):  
Cell Size ◽  
Interactive Effect ◽  
Phosphorus Limitation ◽  
Nitrogen And Phosphorus ◽  
Phytoplankton Cell

Phytoplankton cell size in an urban tropical estuarine system in Northeast Brazil

2021 ◽  
Vol 43 ◽  
pp. 101659
Author(s):  
Nayana Buarque A. Silva ◽  
Manuel Flores-Montes ◽  
Marcella Guennes ◽  
Gislayne Borges ◽  
Carlos Noriega ◽  
...  
Keyword(s):  
Cell Size ◽  
Estuarine System ◽  
Northeast Brazil ◽  
Tropical Estuarine ◽  
Phytoplankton Cell

scholarly journals Effects of nitrogen and phosphorus on the abundance and cell size of planktonic nanoflagellate communities

2013 ◽  
Vol 24 (4) ◽  
pp. 427-437
Author(s):  
Danielle Goeldner Pereira ◽  
Fábio Amodêo Lansac-Tôha ◽  
Gustavo Mayer Pauleto ◽  
Luis Mauricio Bini ◽  
Luiz Felipe Machado Velho
Keyword(s):  
Cell Size ◽  
Nutrient Enrichment ◽  
Nitrogen Addition ◽  
Nutrient Addition ◽  
Heterotrophic Nanoflagellates ◽  
Nitrogen And Phosphorus ◽  
Tropical Reservoir ◽  
Pigmented Nanoflagellates ◽  
Density And Biomass ◽  
Nitrogen And Phosphorus Enrichment

AIM: We experimentally investigated the effects of nutrients (Nitrogen and Phosphorus) enrichment on the density, biomass, and cell size of pigmented and heterotrophic plankton nanoflagellates communities. METHODS: The experiment was done in mesocosms in a tropical reservoir during a 19-day period. Four different treatments were carried out: Control (non-nutrient addition - C), phosphorus additions (P), nitrogen addition (N) and phosphorus + nitrogen addition (N + P). Each treatment was performed in triplicate, sorted randomly, thus giving a total of 12 experimental carboys, which were placed transversely in the middle of the reservoir. RESULTS: In general, pigmented and heterotrophic nanoflagellates fractions responded to nutrient addition, increasing densities and biomass values at the fertilized treatments. Opposed to expected, enriched treatments resulted in a slight decrease in mean cell size of the pigmented fraction. Moreover, in nutrient-rich treatments, pigmented nanoflagellates had higher relative abundance than in the control. CONCLUSIONS: Our results indicate that: i) the density and biomass of nanoflagellates responded to the nutrient enrichment, mainly when N and P were added together; ii) the pigmented and heterotrophic fractions showed distinct time responses to fertilization; iii) the growth of nanoflagellate community seems to be co-limited by N and P; iv) the nutrient enrichment led to a greater pigmented than heterotrophic fraction contribution; and v) among the analyzed variables, nanoflagellate densities seem to be more sensitive to changes in nutrient availability than biomass or mean cell size.

scholarly journals Active reconfiguration of cytoplasmic lipid droplets governs migration of nutrient-limited phytoplankton

2021 ◽  
Author(s):  
Anupam Sengupta ◽  
Jayabrata Dhar ◽  
Francesco Danza ◽  
Arkajyoti Ghoshal ◽  
Sarah Elisabeth Mueller ◽  
...  
Keyword(s):  
Lipid Droplets ◽  
Red Tide ◽  
Mechanical Energy ◽  
Optimal Growth ◽  
Active Role ◽  
Phosphorus Limitation ◽  
Vertical Movement ◽  
Nitrogen And Phosphorus ◽  
And Migration ◽  
Motile Species

As open oceans continue to warm, modified currents and enhanced stratification exacerbate nitrogen and phosphorus limitation, constraining primary production. The ability to migrate vertically bestows motile phytoplankton a crucial – albeit energetically expensive – advantage toward vertically redistributing for optimal growth, uptake and resource storage in nutrient-limited water columns. However, this traditional view discounts the possibility that phytoplankton migration may be actively selected by the storage dynamics when nutrients turn limiting. Here we report that storage and migration in phytoplankton are coupled traits, whereby motile species harness energy storing lipid droplets (LDs) to biomechanically regulate migration in nutrient limited settings. LDs grow and translocate directionally within the cytoplasm to accumulate below the cell nucleus, tuning the speed, trajectory and stability of swimming cells. Nutrient reincorporation reverses the LD translocation, restoring the homeostatic migratory traits measured in population-scale millifluidic experiments. Combining intracellular LD tracking and quantitative morphological analysis of red-tide forming alga, Heterosigma akashiwo , along with a model of cell mechanics, we discover that the size and spatial localization of growing LDs govern the ballisticity and orientational stability of migration. The strain-specific shifts in migration which we identify here are amenable to a selective emergence of mixotrophy in nutrient-limited phytoplankton. We rationalize these distinct behavioral acclimatization in an ecological context, relying on concomitant tracking of the photophysiology and reactive oxygen species (ROS) levels, and propose a dissipative mechanical energy budget for motile phytoplankton for alleviating nutrient limitation. The emergent resource acquisition strategies, enabled by distinct strain-specific migratory acclimatizing mechanisms, highlight the active role of the reconfigurable cytoplasmic LDs in vertical movement. By uncovering a mechanistic coupling between dynamics of intracellular changes to physiologically governed migration strategies, this work offers a tractable framework to delineate diverse strategies which phytoplankton may harness to maximize fitness and resource pool in nutrient-limited open oceans of the future.

scholarly journals Laboratory study on the effects of nutrient enrichment on a phytoplankton population in Sawa Lake, Iraq

2008 ◽  
Vol 5 (2) ◽  
pp. 230-236 ◽  
Author(s):  
Baghdad Science Journal
Keyword(s):  
Population Dynamics ◽  
Lake Water ◽  
Nutrient Enrichment ◽  
Cell Number ◽  
Shannon Index ◽  
Nitrogen And Phosphorus ◽  
Phytoplankton Population ◽  
Phytoplankton Cell ◽  
Nitrogen Phosphorus ◽  
Index Of Diversity

Nutrient enrichment of Sawa lake water was made using different nitrogen and phosphorus concentrations during autumn and spring at three stations. Different concentrations of nitrogen, phosphorus and N: P ratios were used to test variations in phytoplankton population dynamics. Nitrogen at a concentration of 25 µmole.l-1 and N: P ratio of 10:1 gave highest phytoplankton cell number at all stations and seasons. A total of 64 algal taxa dominated by Bacillariophyceae followed by Cyanophyceae and Chlorophyceae were identified. The values of Shannon index of diversity were more than one in the studied stations.

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