BUSCADOR RECOLECTA

The temperature-size rule hypothesized that there is a negative relationship between the size (volume) of an organism and the temperature. This applies to both unicellular and pluricellular organisms. Here, we question this hypothesis for the particular case of protozoans, because in these organisms the volume is directly related to the consumption of prey, and on most of the occasions the true volume of the cell is unknown. To prove our arguments, we designed a series of experiments with the heterotrophic dinoflagellate O. marina, including functional and numerical responses, time-dependent acclimation responses, and estimation of the protozoan volume during long periods of starvation. Our data showed that, in fact, the observed temperature-size rule in unicellular grazers results from anabolic and catabolic imbalances, and that the relationship between size and temperature weakens after proper thermal adaptation. We also showed that once prey are fully digested, the protozoan’ size is the same irrespectively of the temperature. Finally, we set the basis for proper acclimation during short-term temperature experiments, which specifies that at least 3 days should be allowed for proper temperature acclimation. We also suggest that, for trustable experiments, the grazer should be incubated at the target prey concentration for at least 24h before conducting the experiments. The ecological implications of a lack of correlation between microzooplankton size and temperature are also discussed, This research was funded by Grant PID2020-118645RB-I00 by Ministerio de Ciencia e innovación (MCIN)/AEI/ 10.13039/501100011033 and by “ERDF A way of making Europe”. It is a contribution of the Marine Zooplankton Ecology Group (2017 SGR 87). With the institutional support of the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000928-S), Para Oxyrrhis marina: Tasas de ingestion a diferentes concentraciones de alimento (presa/ind/d), Tasa crecimiento (µ 1/d), Volumen (µm3); para la presa (Rhodomonas salina): volume (µm3), Peer reviewed

We exposed the calanoid copepod Paracartia grani, reared in the laboratory at 19°C, to warmer conditions (22°C and 25°C) for 11 generations and examined the direct effects of temperature on feeding, fecundity, development, population sex ratio and somatic traits (adult and egg sizes and adult carbon content), This research was funded by Grants [CTM2017-84288-R and PID2020-118645RB-I00] by MCIN/AEI/10.13039/501100011033 and by “ERDF A way of making Europe”. CJ was supported by Grant [PRE2018-084738] funded by MCIN/AEI/10.13039/501100011033 and by “ESF Investing in your future”, With the institutional support of the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000928-S), Rearing temperature, generation, prosome length, carbon content, ingestion rate, egg production rate, egg diameter, gross-growth efficiency, hatching success, Peer reviewed

The temperature-size rule states that as the temperature increases, the body size of organisms decreases. This rule has been observed in a wide range of organisms, including marine phytoplankton and it is particularly important to model and predict the effects of global warming on the structure and functioning of marine ecosystems. This is so because the size of marine phytoplankton is a critical trait that determines their ecological and biogeochemical roles in marine ecosystems. The size of marine phytoplankton is also affected by resource availability, which relates to growth rates. Here, we compare the effects of a long-term exposure to several temperatures on the cell size of three marine microalgae during their growth curves. The species chosen were the cryptophyte Rhodomonas salina, the dinoflagellate Heterocapsa niei, and the diatom Conticribra (previously Thalassiosira) weissflogii. All algae conformed the temperature-size rule during all the phases of the growth curve. However, the size variations of the microalgae in each of the phases were species-specific. R. salina and H. niei showed higher volumes in the exponential growth phase than during the decline of growth and early stationary phases. Contrarily, the diatom showed smaller volumes during the exponential phase of growth than during the other phases. Overall, the effects of growth rate on cell size exceeded those of temperature for the expected ocean warming by the end of the century. These results also partially support the higher relevance of resource supply than temperature in explaining the variability of phytoplankton size structure in marine ecosystems, This research was funded by Grant PID2020-118645RB-I00 by Ministerio de Ciencia e innovación (MCIN)/AEI/ 10.13039/501100011033 and by “ERDF A way of making Europe”. With the institutional support of the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000928-S), Para las tres microalgas, Rhodomonas salina, Heterocapsa niei, Conticribra weissflogii, abundancias, y volumen a diferentes temperaturas, Peer reviewed

We have studied the response of the marine calanoid copepod Paracartia grani to dietary elemental imbalances, This research was supported by Grant [PID2020-118645RB-I00] funded by MCIN/AEI/10.13039/501100011033, Elemental content, C:N ratios, C:P ratios, N:P ratios, copepod ingestion rate, copepod egg production rate, hatching success, gross-growth efficiency of egg production, egg size, nauplius body size, threshold elemental ratios for C:N and C:P, Peer reviewed

Additional file 1: Movie S1. Time-lapse movie of the system with F-actin forming and treadmilling in the grid., Ministerio de Ciencia, Innovación y Universidades. Ministerio de Ciencia, Innovación y Universidades, Peer reviewed

Additional file 2 Figure S1. Percentage of G-Actin in filaments. Percentage of G-Actin in filaments of different size for the three characteristic regimes., Ministerio de Ciencia, Innovación y Universidades Ministerio de Ciencia, Innovación y Universidades, Peer reviewed

Additional file 3 Figure S2. Dependence of speed of treadmiling with F-actin length. Plot of the dependence of the instantaneous speed on the filament size. Short filaments move faster than average. Long filaments move at the same speed in average., Ministerio de Ciencia, Innovación y Universidades, Peer reviewed

Additional file 4: Movie S2. Time-lapse movie of the system with F-actin and ACs. G-actin is labeled in green, ACs labeled in blue., Ministerio de Ciencia, Innovación y Universidades, Peer reviewed

Additional file 5 Figure S3. G-Actin, F-actin after incorporation of ACs. Number of G-Actin in the grid (green), G-actin as part of networks (orange) and ACs (blue) after incorporation of ACs into the system at t=5E6 iterations. The formation of networks is initial very fast, followed by a regime where incorporation of molecules into networks is gradually slowing down until equilibrium is reached., Ministerio de Ciencia, Innovación y Universidades, Peer reviewed

Additional file 6: Movie S3. Time-lapse movie of the system showing oscillations. Time-lapse movie of the system showing periodic assembly and disassembly of the actomyosin cortex (G-actin labeled in green, ACs labeled in red, Myosin labeled in red)., Ministerio de Ciencia, Innovación y Universidades, Peer reviewed