The effect of low pH on the foraging abilities of the rusty crayfish, Orconectes rusticus.

Abstract

Acidification of freshwater ecosystems is known to be detrimental to the organisms within them. Orconectes rusticus, the rusty crayfish, is a keystone species in littoral food webs of many freshwater ecosystems of northern Michigan. This study investigated the effects of low pH on the foraging abilities of the rusty crayfish. When presented with a choice to investigate an area with a food stimulus or no stimulus, crayfish did not show a preference across a pH range of 6.6 to 8.5. There was a trend for crayfish to choose investigating the area with stimulus less often as acidity increased. These results suggest that crayfish are not strongly affected by lowered pH over a short period of time and may have compensatory mechanisms to deal with acidic environments.