Evidence of Demic Structure for a Population of Yellow Perch (Perca flavescens)

Abstract

A number of authors suggest that yellow perch (Perca flavescens and P. fluviatilis) populations are composed of subpopulations which persist over various periods of time. If the period of time is sufficiently long, then subpopulations may be demes or stocks of perch. These observations are based on the results of tagging studies, comparative growth studies, and behavior patterns of yellow perch. In this paper, evidence is presented which provides additional support for demic structure of yellow perch populations. This evidence consists of yearly egg-mass counts over an extended period of time (1978–87) at a number of distinct sites in a study lake and trapping data by sex, age, and date during one spawning season (1984) at a number of distinct sites in the same lake. Several models concerning perch spawning behavior are introduced to provide a framework for analyzing the data. Analysis of the data not only provides support for demic models of perch population structure, but also provides an estimate of the separation of the demes (0.4–0.5 km).