Skip to main content
Dryad

Chinook salmon digestion data within predatory largemouth bass and channel catfish through controlled feed trials

Data files

Jun 09, 2023 version files 183.18 KB

Abstract

Diet analysis is a vital tool for understanding trophic interactions and is frequently used to inform conservation and management. Molecular approaches can identify diet items that are impossible to distinguish using more traditional visual-based methods. Yet, our understanding of how different variables, such as predator species or prey ration size, influence molecular diet analysis is still incomplete. Here, we conducted a large feeding trial to assess the impact that ration size, predator species, and temperature had on digestion rates estimated with visual identification, qPCR, and metabarcoding. Our trial was conducted by feeding two rations of Chinook salmon (Oncorhynchus tshawytscha) to two piscivorous fish species (largemouth bass (Micropterus salmoides)) and channel catfish (Ictalurus punctatus)) held at two different temperatures (15.5°C and 18.5°C) and sacrificed at regular intervals up to 120 hours from the time of ingestion to quantify the prey contents remaining in the digestive tract. We found that ration size, temperature, and predator species all influenced digestion rate, with some indication that ration size had the largest influence. DNA based analyses were able to identify salmon smolt prey in predator gut samples for much longer than visual analysis (~12 hours for visual analysis versus ~72 hours for molecular analyses). Our study provides evidence that modeling the persistence of prey DNA in predator guts for molecular diet analyses may be feasible using a small set of controlling variables for many fish systems.