Details of individual prey animal samples and respective delta carbon-13 (dC13) and delta nitrogen-15 (dN15) values from a captive feeding experiment of southern rock lobsters (Jasus edwardsii) (Smith et al., 2023). Prey animal species include: longspined sea urchin (Centrostephanus rodgersii) collected by Scuba diving at Fortescue Bay, and blue mussel (Mytilus galloprovincialis) and Australian sardine (Sardinops saga) purchased from Spring Bay seafoods in Tasmania. The experiment took place in Hobart, Tasmania, Australia between June 2020 and December 2021. The experiment was used to determine trophic discrimination factors for stable isotope analysis of lobsters, and investigate variability of stable isotope signatures over time. Isotope values were analysed using flash combustion isotope ratio mass spectrometry.