Responses of the luminescent land snailDyakia (Quantula) striata to natural and artificial lights

Dyakia striata is the only land snail known to produce light. But the function or functions of its luminescence-glowing in eggs and newly hatched snails and flashing in juveniles and most adults-are not known. We conducted 7 experiments to test the responses of juvenileDyakia to natural and artificial lights and to their own lights. Five experiments using artificial lights specifically tested the previously proposed hypothesis that flashing facilitates aggregating of juvenile snails on quickly perishable but temporarily abundant sources of food. There was no evidence to support the hypothesis. In addition, test snails did not show any particular attraction to flashing by otherDyakia; nor did they flash significantly more on mirrored glass than plain glass.