水体钉螺爬行的实验研究

STUDY ON CLIMB MOVEMENT OF ONCOMELANIA HUPENSIS IN WATER

本实验结果显示，在静水和低流速水体中可表现出无方向选择性。随着流速增加，其方向选择性渐趋明显。钉螺在水体流通为25－30cm／s时，只向上（包括左、右侧上方）爬行。在大于30cm／s时，钉螺停止爬行。钉螺的爬行活动可随光照度的增强而增强。并仍具有趋光性和背光性。

The climb movement was observed in the laboratory. Results showed movement of the snail in the still or low current velocity of water without direction. The directed movement was appeared with the increase of current velocity. In the water with 25-30cm/s current ve- locity, the snails climbed directing to the upper only. When current velocity was over 30cm/s, the snails stopped movement. The snail climb was active as the light density increa8e,so that the snail climb has phototaxis and negative phototaxis in water.