Short term fluctuating temperature alleviates Daphnia stoichiometric constraints

BALSEIRO, E; LASPOUMADERES, C; SMUFER, FACUNDO; WOLINSKI, LAURA; MODENUTTI, B

Scientific Reports

Nature Research

Año: 2021 vol. 11

In this study, we analysed how short term temperature fluctuation interacts with nutrient limitationin the vertical migrating Daphnia commutata. We hypothesize that short term (daily) temperaturefluctuation will alleviate nutrient limitation. We carried out experiments analysing growth rates,phosphorus and RNA content of D. commutate grown under four different temperature regimesand two P-limited conditions. Our experiments showed that individuals grown under fluctuatingtemperature grew more than at the mean temperature. We estimated the expected sizes for the 15 °Ctreatment based on the Q10and for the fluctuating temperature treatment. These expected sizes forboth treatments resulted well below the observed ones. The P and RNA content of individuals grownat 10 °C were significantly higher than those at 20 °C, and when individuals grown at 10 °C weretranslocated to 20 °C they exerted an increased growth rate. Our results suggest that, under a regimeof diel vertical migration, the temperature alternation would allow migrating organisms to alleviatethe effect of severe nutrient limitation maintaining population growth. Under a scenario of globalwarming, where epilimnetic temperatures will increase, lake temperature will interact with nutrientlimitation for consumers, but, organisms may be able to face these changes if they can still regularlymove from a cold hypolimnion to a warmer epilimnion.