Student participation in authentic research, as citizen scientists, can improve classroom engagement, achievement of learning objectives, and perceptions of science. We present DNA barcoding of invasive lionfish (Pterois volitans) prey as an example student citizen-science project, though the protocols, objectives, and outcomes can be generalized to any piscivorous fish. The objective of this five-lab conservation genetics unit is to enhance student understanding of fundamental molecular and ecological concepts through applied use of DNA sequencing technologies. Student assessments were equivocal, indicating modest gains in conceptual understanding and maintenance of an overall high perception of science. More notably, student findings have contributed to an improved understanding of the impacts of invasive lionfish, including providing the first evidence that lionfish prey on economically important red snapper (Lutjanus campechanus).