Experimental Evidence That Captured Rusty Crayfish (Orconectes rusticus) Exclude Uncaptured Rusty Crayfish from Entering Traps

ABSTRACT

Baited modified minnow traps are often used to collect rusty crayfish (Orconectes rusticus), an invasive species in many areas of North America. However, the use of baited traps as a collection gear for decapods has received considerable scrutiny. We designed a tank-experiment to determine if captured rusty crayfish exclude uncaptured rusty crayfish from baited traps. We found that significantly more crayfish were captured in traps where captured crayfish were immediately removed (experimental tanks) than in traps where crayfish were not immediately removed (control tanks). In addition, more small crayfish were captured in the experimental tanks. These results are consistent with a hypothesis that large and aggressive previously captured rusty crayfish exclude other, generally smaller, rusty crayfish from the trap.