Have Rusty Crayfish Affected the Diets of Yellow Perch?

Authors

Matthew D. Kvam

Document Type

Article

Abstract

Freshwater ecosystems are some of the most susceptible to invasive species. It is one of the reasons they face the highest levels of species endangerment. Rusty crayfish Faxonius rusticus are one such invasive species, they fragment food webs and negatively affect native species. However, it seems as though native species are beginning to rely on them as a source of food. Yellow perch Perca flavescens, an important forage and game species, is one such species that is highly affected by these invasions. At smaller sizes yellow perch primarily feed on invertebrates whose populations are degraded by rusty crayfish. Therefore, the objective of this study is to assess the effects of the invasive rusty crayfish on the diets of yellow perch. To accomplish this goal, yellow perch were collected throughout the summer of 2022 in an invaded and non-invaded lake. The stomachs of these fish were dissected, the contents were keyed to lowest possible taxonomic group, and counted by individual. Following that, the contents were dried and weighed. While yellow perch diets naturally vary with the season, rusty crayfish have exacerbated these shifts and altered these food webs permanently. Due to the abundance of crayfish found in Cass Lake, fish of a smaller size shift their diets to rely primarily on them leading to significant differences in the diets of the invaded versus natural system.

Publication Date

2023

Comments

Faculty Sponsor: Dr. Andrew Hafs

Recommended Citation

Kvam, Matthew D., "Have Rusty Crayfish Affected the Diets of Yellow Perch?" (2023). Journal of Earth and Life Science. 2.
https://pines.bemidjistate.edu/j-earth-life-sci/2