Utilization of stomach content DNA to determine diet diversity in piscivorous fishes

The objective of the study was to validate and apply DNA-based approaches to describe fish diets. Laboratory experiments were performed to determine the number of hours after ingestion that DNA could be reliably isolated from stomach content residues, particularly with small prey fishes (c. 1 cm, <0·75 g). Additionally, experiments were conducted at different temperatures to resolve temperature effects on digestion rate and DNA viability. The molecular protocol of cloning and sequencing was then applied to the analysis of stomach contents of wild fishes collected from the western basin of Lake Erie, Canada-U.S.A. The results showed that molecular techniques were more precise than traditional visual inspection and could provide insight into diet preferences for even highly digested prey that have lost all physical characteristics.