Invasive
animals pose a serious threat to biodiversity and economic growth.
Throughout the world, invasive species are one of the largest threats
to biodiversity and environmental health. In West Virginia, two
invasive species of crayfish, Orconectes rusticus and
Orconectes virilis, have
become increasingly common while threatening to displace native
species and destroy aquatic habitats. Aggressive interactions
favoring larger, invasive crayfish are thought to give these species
advantages over indigenous crayfish. This research investigated
behavioral interactions between indigenous species and O.
rusticus and found that there
was actually no significant difference in aggression between species
or genera. This suggests other factors influence its ability to
rapidly establish population in new environments. Using
radio-telemetry, O. virilis were
tracked in the field in order to understand ranging patterns and the
dispersal potential of this species. Daily movement was much higher
than expected and crayfish did not seem affected by the direction of
current. Previously it was thought that crayfish primarily moved less
than one meter per day, only migrating downstream when carried by
currents. This research observed O. virilis
able to move dozens of meters per day, unaffected by direction of
current. Orconectid crayfish have been traditionally thought of as
aggressive species spread by human introductions to new environments,
but this work suggests a very different picture. The species studied
did not seem to rely to on aggression to establish dominance, and
ultimately may be able to disperse themselves more effectively than
native species.
