Characterizing Piscivory from Ingested Remains

A series of linear regressions was generated to estimate live length from partially digested ciscoes Coregonus artedii, yellow perch Perca flavescens, and slimy sculpins Cottus cognatus recovered from formaldehyde‐preserved stomachs of lake trout Salvelinus namaycush. Back calculation of original size of prey involved four body dimensions (total length, fork length, standard length, and tip of snout to posterior margin of last vertebra) and lengths of four skeletal parts (axial skeleton, two vertebrae, and the first hypural). Sample size and forage size range were increased through use of the full array of regressions over those from a single measurement. This technique should be considered for ecological studies that require detailed diet analyses to examine trophic dynamics, growth, energetics, or production.