Movement of Aquatic Oxygenic Photosynthetic Organisms

Raven, John A.; Lavoie, Michel

doi:10.1007/124_2021_55

Cited by 3 publications

(1 citation statement)

References 135 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Maximum ingestion rate is expected to be limited by the time it takes to handle and ingest prey (Suzuki et al 2021), or by the time it takes to digest prey (Jeschke et al 2002). These processes may be more energetically expensive than the flagellar motion driving C max (Raven and Lavoie 2021), which could lead to a greater reduction in I max when mixotrophs invest energy in phototrophy instead of phagotrophy. The inclusion of relatively bulky photosynthetic machinery in the cell could also reduce the maximum digestion rate by reducing the number of prey that can be simultaneously digested.…”

Section: Discussionmentioning

confidence: 99%

Ingestion kinetics of mixotrophic and heterotrophic flagellates

Edwards

Steward

2023

Limnology & Oceanography

View full text Add to dashboard Cite

In sunlit waters, significant predation is performed by unicellular, phagotrophic mixotrophs, that is, predators that also possess plastids. The success of a mixotrophic lifestyle will depend in part on how well mixotrophs acquire prey relative to specialized heterotrophs. Likewise, consequences of mixotrophy for productivity and element cycling will depend on the rate and efficiency at which mixotrophs consume prey biomass relative to heterotrophs. However, trait differences between mixotrophs and heterotrophs are not well characterized. In addition, cell size of mixotrophs varies widely, and constitutive mixotrophs include small flagellates deriving from diverse taxa, while larger species are primarily dinoflagellates. To determine whether similar constraints apply to phagotrophs across this broad range of size and taxa, we compiled 83 measurements of flagellate functional responses and compared maximum clearance rates (Cmax) and maximum ingestion rates (Imax) between trophic modes. We found that the average mixotroph has a 3.7‐fold lower Cmax and 7.8‐fold lower Imax than the average heterotroph, after controlling for cell size. The smaller penalty for Cmax suggests that relative fitness of mixotrophs will be enhanced under dilute prey concentrations that are common in pelagic ecosystems. We also find that growth efficiency is greater for mixotrophs and for flagellates with lower Cmax, indicating a spectrum of trophic strategies that may be driven by phototrophy vs. phagotrophy allocation as well as fast vs. slow metabolic variation. Allometric scaling shows that Imax is constrained by a common relationship among dinoflagellates and other taxa, but dinoflagellates achieve a greater volume‐specific Cmax. These results should aid in interpreting protistan communities and modeling mixotrophy.

show abstract

Section: Discussionmentioning

confidence: 99%

Ingestion kinetics of mixotrophic and heterotrophic flagellates

Edwards

Steward

2023

Limnology & Oceanography

View full text Add to dashboard Cite

show abstract

Dynamic adaptation of phytoplankton vertical migration to changing grazing and nutrient conditions

Salonen,

Järvinen,

Aalto

et al. 2024

Hydrobiologia

View full text Add to dashboard Cite

Despite the ubiquitous occurrence of vertical migration of phytoplankton its quantitative significance remains poorly known. We eliminated a dense Daphnia population in a pond by introducing whitefish fingerlings, and assessed the effects on the vertical migration of dominating motile phytoplankton. At the highest abundance of Daphnia, cryptophytes reduced grazing losses by staying in the hypolimnion day and night, but Mallomonas species armoured by silica bristles remained in the epilimnion. After the fish introduction, phytoplankton was released from Daphnia grazing pressure, allowing cryptophytes to occur in the epilimnion also at noon. At the same time, increased phytoplankton biomass exacerbated the nutrient depletion. Cryptophytes compensated for that by migrating into the anoxic hypolimnion, whereupon their growth rates increased. The collapse of Daphnia was also associated with a temporary increase in nutrient regeneration by enzyme activities and decreases in total nutrient concentration and bacterial biomass in the whole water column. Our results show that cryptophytes can dynamically modify their vertical migration to balance between the exploitation of various nutrient resources and the risk of becoming eaten. Hypolimnetic nutrient resources can be quantitatively more important for phytoplankton than previously assumed.

show abstract

Evolution of Phytoplankton in Relation to Their Physiological Traits

Raven

Beardall

2022

JMSE

View full text Add to dashboard Cite

Defining the physiological traits that characterise phytoplankton involves comparison with related organisms in benthic habitats. Comparison of survival time in darkness under natural conditions requires more information. Gas vesicles and flagella as mechanisms of upward movement relative to surrounding water, allowing periodic vertical migration, are not confined to plankton, although buoyancy changes related to compositional changes of a large central vacuole may be restricted to plankton. Benthic microalgae have the same range of photosynthetic pigments as phytoplankton; it is not clear if there are differences in the rate of regulation and acclimation of photosynthetic machinery to variations in irradiance for phytoplankton and for microphytobenthos. There are inadequate data to determine if responses to variations in frequency or magnitude of changes in the supply of inorganic carbon, nitrogen or phosphorus differ between phytoplankton and benthic microalgae. Phagophotomixotrophy and osmophotomixotrophy occur in both phytoplankton and benthic microalgae. Further progress in identifying physiological traits specific to phytoplankton requires more experimentation on benthic microalgae that are closely related to planktonic microalgae, with attention to whether the benthic algae examined have, as far as can be determined, never been planktonic during their evolution or are derived from planktonic ancestors.

show abstract

Movement of Aquatic Oxygenic Photosynthetic Organisms

Cited by 3 publications

References 135 publications

Ingestion kinetics of mixotrophic and heterotrophic flagellates

Ingestion kinetics of mixotrophic and heterotrophic flagellates

Dynamic adaptation of phytoplankton vertical migration to changing grazing and nutrient conditions

Evolution of Phytoplankton in Relation to Their Physiological Traits

Contact Info

Product

Resources

About