Feeding ecology of the invasive round goby, Neogobius melanostomus (Pallas, 1814), based on laboratory size preference and field diet in different habitats in the western basin of Lake Erie

Melanie Perello,Hilary Thompson,Thomas Simon,Douglas Kane

doi:10.3391/ai.2015.10.4.09

Abstract

The round goby, Neogobius melanostomus, is an invasive benthic fish species in the Laurentian Great Lakes that is threatening native fish populations through competition, predation, and trophic dynamic change. This study examined the trophic dynamic plasticity of round goby along a depth gradient based on laboratory and field observations to determine prey species consumed and mussel prey size selection. Prey size selection in the laboratory was assessed by presenting individual round goby with quagga mussels ( Dreissena rostriformis bugensis) of various class sizes (i.e., 6.0– 9.9 mm, 10.0– 12.9 mm, 13.0– 15.9 mm, and 16.0– 18.9 mm in length). Round goby exhibited a selection preference for small sized quagga mussels, although in individual trial events, mussels were consumed from all four size classes. Prey species consumed from shallow and deep sites in the western basin of Lake Erie were assessed using individual gut contents to calculate measures of prey importance, diversity, and dominance. Based on the Index of Relative Importance (IRI), Cladocera was found to be the most consumed prey item for both males and females and between study sites. Both sexes consumed a variety of prey items although females exhibited greater prey dominance or reliance on one prey item. Round goby individuals at the shallow, natural shoreline site had the highest trophic diversity, while individuals at the deep site exhibited the highest prey dominance. Diet of round goby in the western basin of Lake Erie are mainly dominated by just a few prey items.

Highlights

Community level trophic dynamics, including feeding ecology, are important in understanding interactions between invasive and native species (Arim et al 2006; Crowl et al 2008; France and Duffy 2006; Gido and Brown 1999; Lepak et al 2006; Parker et al 1999; Vander Zanden and Olden 2008)
Previous studies have focused on consumption of dreissenid mussels by round goby based on sex (Andraso et al 2011b; Thompson and Simon 2014) but did not find sex to be a significant predictor (Andraso et al 2011b) or have not evaluated selection of prey organisms compared to relative abundance of organisms in various habitats (Ray and Corkum 1997)
Andraso et al (2011b) assessed dreissenid relative abundance in the environment, but found that non-dreissenid prey comprised a trivial portion of round goby diet

Summary

Introduction

Community level trophic dynamics, including feeding ecology, are important in understanding interactions between invasive and native species (Arim et al 2006; Crowl et al 2008; France and Duffy 2006; Gido and Brown 1999; Lepak et al 2006; Parker et al 1999; Vander Zanden and Olden 2008). Feeding ecology studies can be useful in the management of invasive species by providing key clues on how invasive species can alter system trophic dynamics and can be used to predict interactions especially in sympatric areas with similar habitat and diet preference (Kolar and Lodge 2001; Shea and Chesson 2002; Thompson and Simon 2014). Ecologicalenvelope model predictions can be used by ecosystem managers to focus their efforts to mitigate the invasive species’ impact

Methods

Results

Conclusion