Stable isotope values (δ15N) and carbon (δ13C) from white muscle tissue from 191 specimens of claroteine and Synodontis catfishes from Lake Tanganyika (Zambia). A total of 113 claroteine specimens (minimum 1, maximum 22, median 10 specimens per species) and 78 Synodontis specimens (minimum 11, maximum 21, median 16 specimens per species) as well as a variety of pelagic and littoral basal resources. Please refer to Peart et al. (2024) Evolutionary Journal of the Linnean Society, Supporting Information Table S1 for the full list of samples included.