Fig. 1. The effect of protein synthesis blockers on transcription (Actinomycin D) and translation (Anisomycin) on spontaneous aerial respiratory behaviour in Lymnaea. (A) Breathing time observed during a 30 min session in hypoxic pondwater, at 2.5, 4.5, 8 and 24 h post-injection in (1) non-injected controls, (2) saline-injected controls, (3) Actinomycin D- and (4) Anisomycin-injected Lymnaea. All injections were into the foot of the snail. (B) Number of pneumostome openings observed using the above protocol. (N=20-25; see text).