Fig. 5. Motivated juveniles do not exhibit better learning than control juveniles. To motivate juvenile snails we submerged them in hypoxic pond water for 30 min before training. (A) Preventing juvenile snails from performing aerial respiration for 30 min (i.e. submerged juveniles) before the observation period significantly increases their total breathing time. Plotted are the total breathing time (mean ± S.E.D.) for adults (N=15, clear bar), juveniles (N=15, grey bar) and submerged juveniles (N=12, striped bar). The submerged juveniles breathe significantly longer than control juveniles (P<0.01) and statistically the same as adults. (B) Submerged juveniles (N=28, striped bars) received operant conditioning training immediately after being submerged. The number of attempted openings of the submerged juveniles in session 1 was not significantly different to adults (P>0.05). These snails had a 27% reduction in the number of attempted openings in session 2 compared with session 1. Control juvenile snails exhibited a 24% reduction in session 2 compared with session 1.