BALSEIRO esteban Gabriel
Short term fluctuating temperature alleviates Daphnia stoichiometric constraints
BALSEIRO, ESTEBAN; LASPOUMADERES, CECILIA; SMUFER, FACUNDO; WOLINSKI, LAURA; MODENUTTI, BEATRIZ
Año: 2021 vol. 11
In this study, we analysed how short termtemperature fluctuation interacts with nutrient limitation in the verticalmigrating Daphniacommutata. We hypothesize that short term (daily) temperature fluctuationwill alleviate nutrient limitation. We carried out experiments analysing growthrates, phosphorus and RNA content of D. commutata grown under four differenttemperature regimes and two P-limited conditions. Our experiments showed thatindividuals grown under fluctuating temperature grew more than at the meantemperature. We estimated the expected sizes for the 15°C treatment based onthe Q10 and for the fluctuating temperature treatment. Theseexpected sizes for both treatments resulted well below the observed ones. The Pand RNA content of individuals grown at 10°C were significantly higher thanthose at 20°C, and when individuals grown at 10°C were translocated to 20°C theyexerted an increased growth rate. Our results suggest that, under a regime ofdiel vertical migration, the temperature alternation would allow migrating organismsto alleviate the effect of severe nutrient limitation maintaining populationgrowth. Under a scenario of global warming, where epilimnetic temperatures willincrease, lake temperature will interact with nutrient limitation forconsumers, but, organisms may be able to face these changes if they can stillregularly move from a cold hypolimnion to a warmer epilimnion.