The effects of green crab Carcinus maenas predatory cues on the burrowing depth and morphology of the soft shell clam Mya arenaria

by Louis Valentine Plough

In this laboratory study, Mr. Plough examined the response of soft shell clams to green crab predation cues. A chemical cue (crab and crushed clam conspecifics) and a tactile cue and their interaction were analyzed over a seven-week period for their effects on clam burrowing depth, siphon length, siphon mass, and change in shell length. Clams exposed to chemical cues burrowed more deeply than control clams, or those exposed to the tactile cue. Neither treatment had a significant effect on increasing shell thickness or siphon length, although there was a pattern of less growth and thicker shells in clams that were exposed to the combination of the two cues. These results suggest that the most effective resonse to green crab avoidance is to increase burrowing depth and that M. arenaria invest more of their energy in burrowing compared to any other predation response.