Food habits of imperiled Plains Topminnow and diet overlap with invasive Western Mosquitofish in the Central Great Plains

Authors

Joseph Thiessen, University of Nebraska at KearneyFollow
Keith D. Koupal, Nebraska Game and Parks CommissionFollow
Casey W. Schoenebeck, University of Nebraska at KearneyFollow
Julie J. Shaffer, University of Nebraska, Kearney

Date of this Version

Winter 3-1-2018

Document Type

Article

Citation

Thiessen, Joseph D., Keith D. Koupal, Casey W. Schoenebeck, & Julie J. Shaffer. Food habits of imperiled Plains Topminnow and diet overlap with invasive Western Mosquitofish in the Central Great Plains, Transactions of the Nebraska Academy of Sciences 38 (2018), 1–9. doi: 10.13014/K2319T31

Comments

Copyright (c) 2017 Joseph D. Thiessen, Keith D. Koupal, Casey W. Schoenebeck, and Julie J. Shaffer.

Abstract

Plains Topminnow (Fundulus sciadicus) populations have experienced large declines throughout the Central Great Plains, with Western Mosquitofish (Gambusia affinis) introductions suggested as a contributing factor. There are limited studies identifying the food habits of Plains Topminnow and the trophic interactions with Western Mosquitofish. This study sought to determine if a diet overlap exists between the Plains Topminnow and the introduced Western Mosquitofish by identifying the feeding habits of both species. We analyzed diets from lentic and lotic populations of Plains Topminnow captured in August and found lentic topminnows employed a generalist diet while lotic topminnow selected for gastropods. Additionally, Western Mosquitofish diets from regionally proximate lotic and lentic populations also displayed a generalist diet consisting of benthic, littoral and terrestrial macroinvertebrates. The two species did not show overlapping diets based on Schoener’s Index. Therefore we suggest the introduced Western Mosquitofish do not likely impact Plains Topminnow populations through food resource competition.