Outside Heat
Posted by lisa on April 30, 2004
Q: At what high temperature will a daphnia (water flea) become too hot and die at? What happens to their heart when this happens? Also what temperature is too cold for the daphnia to live in and what happens to their heart when they are exposed to it?
A: Since there are many different species of daphnia, what might kill one
species, might not kill another. I do know however, that at 28C (82F),
daphnia can live just fine but their life processes speed up quite a bit
(their life span is much shorter as a result). When a daphnia dies, its heart stops
beating. In the north, daphnia overwinter in ponds and lakes so they can
live in water that approaches 0C (32F). In cold water, their heart rate
slows, as compared to warmer water.
John Wiessinger ( May 3, 2004)