Fig. 2. Behavioral response of wild Belly (left black bars) and laboratory snails (descendents of wild Dutch snails; right white bars) after a single 0.5 h training session (TS). (A) Operant conditioning of wild Belly snails results in an LTM that persists for 24 and 72 h (24 h TM, N=53, P<0.05; 72 h TM, N=23, P<0.05). Yoked control snails do not demonstrate memory at these same time periods (faded bars; 24 h yoke, N=26, P=0.36; 72 h yoke, N=25, P=0.45). Snails did not demonstrate memory after 1 week (1 week TM, N=32, P=0.24). (B) Laboratory snails do not demonstrate LTM after a single 0.5 h training session (TS; 24 h TM, N=30, P=0.55; 24 h yoke, N=15, P=0.42). All results shown as means + s.e.m. ^**P<0.001.