TEMPERATURE AND PHENOTYPIC PLASTICITY IN THE SHELL COLOR AND BANDING OF THE LAND SNAIL HELIX-ASPERSA

Phenotypic plasticity of shell pigmentation in the land snail Helix as persa was investigated with the help of image processing followed by p ixel counting for each colour present on the shell. Thus, the use of t hree different growth temperatures under artificial conditions showed, for the two subspecies considered, a continuous colour gradient from red to dark of the shell banding. Darker pigmentation characterized lo w temperatures while red bands were related to the higher temperature (25 degrees C). No interpretable difference appeared between the two f orms. ((C) Academie des sciences / Elsevier, Paris.).