The external aspect of three C. gibbosa individuals is shown
in Fig. 5. The organisms were transferred from the vessels to a
Petri dish and photographed through a magnifying glass. As can
be appreciated, the head–foot region on control snails (Fig. 5a) can
barely be seen as it is usually fully or partially hidden inside the
shell. These animals present normal locomotion, movements and
adherence to recipients. Conversely, in treated organisms (Fig. 5b,c)
the heat-foot region emerges completely from the shell which correlates
with lack of adherence and mobility, and weak response to
external stimuli.