Data were collected from lethal samples of pumpkinseed either from laboratory experiments or field collections. All measurements were collected within 4 hours of fish euthanization. All euthanized fish were kept on ice and collected with appropriate animal care protocol approvals and animal collections permits (see manuscript for more information). The attached data file includes unprocessed raw data (organ and fish masses). Indices followed by a "1" (GSI1 = GSI; LSI1 = HSI) were calculated as indicated in the manuscript. Indices without a "1" were calculated without removing the mass of the indexed organ from fish wet weight (e.g., LSI = HSI = WETLIVWT / WETBODWT*100).

Organ masses (WETGONWT: gonad; WETLIVWT: liver) were recorded in milligrams and whole fish body masses are in grams. Male fish are coded as "1" and females are coded as "2." Fish length was recorded as fork length in millimetres. Ash weight and water content were inconsistently recorded so there are missing values throughout these columns. EXPTCD 11-17 contain data for experimental spring warming treatments, and EXPTCD 92-93 contain data for field collections. Other EXPTCD's were used to generate the figures in the Appendix and Figure S2 in the Supplementary Material, including data from fish held in large tanks over the course of the project (see README_DataDictionary). Please do not hesitate to reach out to the corresponding author if you have any questions!