Fig. 3. Seat patch and fully immersed water uptake from DI water or NaCl (50 mol l^–1) in B. alvarius (A) and B. marinus (B). Each column represents mean ± 1 s.e.m. for 15 trials, except seat patch water uptake from NaCl (12 trials). Regional water uptake read from the pipette or determined gravimetrically (broken lines) were not different. Regional seat patch water uptake was significantly lower from NaCl (**P<0.01). In contrast, full immersion resulted in significantly higher water uptake from NaCl (B. alvarius, *P<0.05; B. marinus, ***P<0.001). There were no differences between B. marinus and B. alvarius in water absorption from a given rehydration source.