Meeting Abstract
The rusty crayfish Orconectes rusticus is an invasive species that has undergone significant range expansion throughout the northeastern United States and southern Canada. The omnivorous diet and aggressive behavior of the rusty crayfish make them superior competitors to many of the native species they encounter, and thus rusty crayfish invasion has been shown to cause significant disruptions to the structure of invaded communities. Despite widespread management efforts to limit further expansion of the rusty crayfish, relatively little is known about the dietary requirements of the species. A more in-depth understanding of the dietary requirements of the species is needed to develop more effective management strategies. Furthermore, little effort has been made to study rusty crayfish within their native range where native conditions have shaped their feeding niche. This study aimed to elucidate the food resource use of the rusty crayfish within their natural range of the Ohio River Valley and identify the most important food resources for the species. Specimens of various sizes (and thus ages) of both sexes were collected monthly from the same location in a small, rocky stream in southeastern Ohio. The stomach contents of collected specimens were dissected out and analyzed for diet composition. As expected, detritus was the most frequently observed dietary item. Diatoms were the second most frequently encountered food item, suggesting that rusty crayfish may supplement their scavenging with suspension feeding. Animal tissue was not commonly observed in many of the analyzed stomachs, suggesting that rusty crayfish may be deprived of protein in their natural diet.
