Quagga mussels (Dreissena rostriformis bugensis) first invaded the Laurentian Great Lakes via ballast water discharge in the late 1980s and have since spread to cool, deep inland lakes and rivers from the Great Lakes to as far west as California. They have significantly altered nutrient cycling, reduced zooplankton biomass, and disrupted microzooplankton communities, impacting prey availability for planktivorous fish such as yellow perch (Perca flavescens). However, the impacts of quagga mussel veligers (free-swimming larvae) on fish that consume them remains poorly understood. Additionally, understanding morphological and physiological differences between geographically distinct quagga mussel populations is critical for deciphering invasion pathways and developing control strategies. This research aimed to: 1) determine how veligers affect yellow perch survival, growth, and diet in a laboratory setting; 2) assess diet preferences and feeding success of yellow perch in Lake Michigan, including the incidence of empty stomachs; and 3) compare morphology and physiological responses to stressors between adult quagga mussel populations in Lake Mohave, NV,(a recent invasion) and the Detroit River, MI (an older invasion). Laboratory experiments indicated that yellow perch larvae fed a veliger rich diet had reduced survival and lower growth compared to those fed Artemia nauplii. Field data showed that yellow perch preferentially consumed veligers when abundant but avoided them when native prey was more available. Smaller fish had higher rates of empty stomachs, suggesting feeding success is closely tied to fish size and may influence survival. This shift toward veliger consumption could exacerbate challenges like prey composition or availability, potentially hindering yellow perch recruitment success. Finally, adult quagga mussels from Lake Mohave and the Detroit River exhibited distinct morphological traits and physiological responses to cyanobacteria exposure. This research provides novel insights into the ecological impacts of quagga mussel veligers on yellow perch and demonstrates how distinct dreissenid populations may acclimate to local environmental conditions.