Effect of damage by the snail Lymnaea (Lymnaea) stagnalis (L.) on the growth of Elodea canadensis Michx.

摘要

The response of Elodea canadensis to grazing damage from the snail Lymnaea (Lymnaea) stagnalis was analysed in laboratory experiments. The type and degree of damage to Elodea as well as the post-damage growth of the plants were examined. Lymnaea (2-3 g fresh weight) consumed 35-260 mg fresh weight of Elodea daily. More than 90% of the plant material remaining after snail grazing bore clear signs of damage, with over 70% showing more than one kind of injury. Fragmentation of plants was noted most frequently, followed by damage to leaves and growing tips. Grazing scars on the surface of stems occurred more rarely.