[Next slide] [Previous slide] [Other navigation] [current slide = 143 of 211]

As the flood tide comes in, little insects and snails which live among the grasses ascend the stalks. These melampus bidentatus or salt marsh snails normally stay in damp areas beneath the mats of patens; however, since they breath through a lung and cannot breath under water, they must climb grass stems to remain above flood tides. If they are covered by the tide, they can only hold their breath for an hour. The melampus somehow has an internal alarm clock which allow it to anticipate the daily tides and begin to climb before the water arrives.
[Click for next slide]