Data for: Egg size scales negatively with system size in a periodic fish species

<p>To assess potential intraspecific variation of fish egg size over a gradient of system sizes, we collected yellow perch (<em>Perca flavescens</em>) from 12 locations across systems ranging in surface area from 37 to 5,390,492 hectares. Sampling took place in 2018, 2019 and 2023. When we captured spawning female yellow perch, we measured their total lengths and collected unfertilized egg samples to be stored in 10% formalin. We imaged preserved eggs under a dissecting microscope and measured their diameters with ImageJ software. For each female, we randomly selected 10 eggs, from which we measured two perpendicular diameters. From these measurements, we obtained a mean egg diameter value to correspond with each individual female. Through analysis we found that on average, yellow perch egg size decreased as system surface area increased.</p>