Feeding Patterns and Diet Overlap of Muskellunge and Co-occurring Piscivores in Minnesota Lakes

Author

Kamden Glade

Date of Award

12-2021

Document Type

Thesis

Department

Biology

First Advisor

Andrew Hafs

Abstract

Muskellunge Esox masquinongy are the largest member of the family Esocidae found in Minnesota and are managed for trophy angling opportunities with large minimum size requirements, limited harvest, and stocking to support existing populations or expand angling opportunities. While Muskellunge impacts at the community level appear minimal based on available literature, relatively little is known about Muskellunge diets, eat the le particularly in Minnesota. In this study, we used gastric lavage to examine gut contents of Muskellunge, Northern Pike Esox lucius, Walleye Sander vitreus, and Largemouth Bass Micropterus salmoides. Diets were quantified using an index of relative importance (IRI) and diet overlap among species was determined using Pianka's index of niche overlap and non-parametric multi-dimensional scaling (NMDS) ordinations. Our experimental design focuses on how the presence or absence of Cisco Coregonus artedi impacts diet and overlap, while lakes without Muskellunge were also sampled to compare diets of other piscivores in their presence or absence. Yellow Perch Perca flavescens and various centrarchids were important prey items across all lakes for Muskellunge, Northern Pike, and Walleye, while crayfish Faxonius spp. and other aquatic invertebrates were critical for Largemouth Bass. Pianka's index of niche overlap indicates that Muskellunge had low levels of dietary overlap with other predators, while Northern Pike and Walleye had relatively high levels of dietary overlap. Additionally, diet overlap tended to be lower among all species when Cisco were present, even though direct predation on Cisco was rarely observed. These results corroborate existing research on diets of Muskellunge, Northern Pike, Walleye, and Largemouth Bass in their native range.

Recommended Citation

Glade, Kamden, "Feeding Patterns and Diet Overlap of Muskellunge and Co-occurring Piscivores in Minnesota Lakes" (2021). Biology Graduate Theses. 11.
https://pines.bemidjistate.edu/thesis-biol/11