Validation of annulus formation in white perch otoliths, including characteristics of an invasive population

Abstract

Accurately ageing fish is essential for fisheries managers when calculating population dynamics for a particular species. Despite being a popular sport fish in its native range with a large expanding non-native range, otoliths of white perch Morone americana have not been validated. White perch were collected monthly during 2015–2016 from Sooner Lake, Oklahoma to remove sagittal otoliths to validate annulus formation. Marginal increment analysis verified a single annulus formed once yearly in otoliths of white perch and formation was complete by April or June, depending on fish age. Because descriptions of population characteristics of invasive white perch in Oklahoma are limited, the dynamics of the Sooner Lake population was described. The Sooner Lake white perch population is characterized by rapid growth rates, average longevity and mortality rates, high proportional size distribution and below average condition. The Sooner Lake population is a non-stunted population, which has not previously been documented in Oklahoma. White perch form a single opaque band once annually in sagittal otoliths, validating this structure as an ageing method for this species. This study expands on the existing literature on invasive white perch population characteristics and serves as a reference to which other Oklahoma populations can be compared.