Clonal variation in behavior in the invasive New Zealand mud snail (Potamopyrgus antipodarum)

Background/Question/Methods

Behavior can be an important determinant of invasion success.  In the New Zealand mud snail (Potamopyrgus antipodarum), behavior has been shown to be influenced by both light and gravity. The snail exhibits positive geotaxis (moves down) and positive photokinesis (moves faster in light than in dark). The present study investigated differences in behavior between different asexual clones of this species and compared invasive and non-invasive clones of snails with respect to geotactic and photokinetic behaviors.  The influence of crayfish and piscine predators on the behavior of different clones was also studied.

Results/Conclusions

There was a significant difference in behaviors between clone types in the snails in response to light and gravity. Interestingly, the most invasive clone behaved most differently from the other clones.  Preliminary results also indicate that the detection of crayfish and fish may also have clone-specific effects on behavior.  These results indicate that there is a genotypic effect on behaviors in this freshwater snail, and this variation may help to explain why some clones are more invasive than others.