Thermal phenotypic plasticity of the second limb in <i>Daphnia</i>

Abstract Thermal plasticity is expected to affect the responses of freshwater zooplankton climate perturbations. We tested hypothesis thermal in rigid setae second limb Daphnia galeata. also aimed test role allometry and ability induce a rapid plastic response within an individual lifetime (i.e. postnatal). In all, 300 specimens were dissected from four sets clonal transfers seasonal variants nature. Specimens D. galeata cultured under identical conditions save temperature (10 20°C). Clonal neonates reciprocally transferred across regimes determine degree postnatal plasticity. Setae length ratios supported seta 2, but effect was not significant for soft setae. Simple linear regressions body (mm) lengths warm cold revealed slope differences allometry) among temperatures three examined. The had largest size (slope difference), growing larger at colder given compared seta. Rapid non-filtering limbs more important than previously appreciated Daphnia.