Date of Award


First Advisor

Robert Schmidt

Second Advisor

David Myers


The green sunfish (Lepomis cyanellus) is a species of sunfish native to the Midwestern United States. As a result of introduction, non-native populations exist in drainages all over the country. Few studies have been conducted to examine the effects of this species on native ecosystems in areas in which it has been introduced. The objective of this research was to investigate the green sunfish population on the Simon’s Rock campus to determine whether the population was successful and what characteristics of the location would make it successful. Fish were collected and weight, length, age, stomach content, and habitat data were used to gain an understanding of what characteristics of a location contributed to green sunfish success. Habitats with calm, shallow water and plenty of shelter were preferred by the green sunfish. The fish that inhabited these locations were significantly larger than fish in less ideal locations. Analysis of stomach contents revealed that their diets consisted of other fish, crayfish, and aquatic and terrestrial macroinvertebrates. Significant overlap of diet and habitat with a closely related native species, the pumpkinseed (Lepomis gibbosus), gives the more tolerant green sunfish the opportunity to outcompete the native species. Although green sunfish have the potential to outcompete native species of fish, the data do not imply that they pose an immediate threat. At this time, I do not believe that they should be considered invasive on the Simon’s Rock campus.