TY - JOUR

T1 - Defining planktonic protist functional groups on mechanisms for energy and nutrient acquisition

T2 - incorporation of diverse mixotrophic strategies

AU - Mitra, Aditee

AU - Flynn, Kevin J.

AU - Tillmann, Urban

AU - Raven, John A

AU - Caron, David

AU - Stoecker, Diane K

AU - Hansen, Per Juel

AU - Hallegraeff, Gustaff

AU - Sanders, Robert

AU - Wilken, Susanne

AU - Mcmanus, George

AU - Johnson, Matthew

AU - Pitta, Paraskevi

AU - Våge, Selina

AU - Berge, Terje

AU - Calbet, Albert

AU - Thingstad, Frede

AU - Jeong, Hae Jin

AU - Burkholder, JoAnn

AU - Glibert, Patricia M

AU - Granéli, Edna

AU - Lundgren, Veronica

PY - 2016

Y1 - 2016

N2 - Arranging organisms into functional groups aids ecological research by grouping organisms (irrespective of phylogenetic origin) that interact with environmental factors in similar ways. Planktonic protists traditionally have been split between photoautotrophic “phytoplankton” and phagotrophic “microzooplankton”. However, there is a growing recognition of the importance of mixotrophy in euphotic aquatic systems, where many protists often combine photoautotrophic and phagotrophic modes of nutrition. Such organisms do not align with the traditional dichotomy of phytoplankton and microzooplankton. To reflect this understanding, we propose a new functional grouping of planktonic protists in an eco-physiological context: (i) phagoheterotrophs lacking phototrophic capacity, (ii) photoautotrophs lacking phagotrophic capacity, (iii) constitutive mixotrophs (CMs) as phagotrophs with an inherent capacity for phototrophy, and (iv) non-constitutive mixotrophs (NCMs) that acquire their phototrophic capacity by ingesting specific (SNCM) or general non-specific (GNCM) prey. For the first time, we incorporate these functional groups within a foodweb structure and show, using model outputs, that there is scope for significant changes in trophic dynamics depending on the protist functional type description. Accordingly, to better reflect the role of mixotrophy, we recommend that as important tools for explanatory and predictive research, aquatic food-web and biogeochemical models need to redefine the protist groups within their frameworks.

AB - Arranging organisms into functional groups aids ecological research by grouping organisms (irrespective of phylogenetic origin) that interact with environmental factors in similar ways. Planktonic protists traditionally have been split between photoautotrophic “phytoplankton” and phagotrophic “microzooplankton”. However, there is a growing recognition of the importance of mixotrophy in euphotic aquatic systems, where many protists often combine photoautotrophic and phagotrophic modes of nutrition. Such organisms do not align with the traditional dichotomy of phytoplankton and microzooplankton. To reflect this understanding, we propose a new functional grouping of planktonic protists in an eco-physiological context: (i) phagoheterotrophs lacking phototrophic capacity, (ii) photoautotrophs lacking phagotrophic capacity, (iii) constitutive mixotrophs (CMs) as phagotrophs with an inherent capacity for phototrophy, and (iv) non-constitutive mixotrophs (NCMs) that acquire their phototrophic capacity by ingesting specific (SNCM) or general non-specific (GNCM) prey. For the first time, we incorporate these functional groups within a foodweb structure and show, using model outputs, that there is scope for significant changes in trophic dynamics depending on the protist functional type description. Accordingly, to better reflect the role of mixotrophy, we recommend that as important tools for explanatory and predictive research, aquatic food-web and biogeochemical models need to redefine the protist groups within their frameworks.

U2 - 10.1016/j.protis.2016.01.003

DO - 10.1016/j.protis.2016.01.003

M3 - Journal article

C2 - 26927496

VL - 167

SP - 106

EP - 120

JO - Protist

JF - Protist

SN - 1434-4610

IS - 2

ER -