Molecular and behavioral evidence suggest two distinct life histories are displayed in Smallmouth Bass (Micropterus dolomieu) in Lake Erie.

Abstract

In Lake Erie Smallmouth bass (Micropterus dolomieu) are an ecologically and economically important species. They are a top littoral predator as well as a popular sport fish. Previous genetic research suggests bass that live and spawn solely in the lake are genetically divergent compare to bass that live and spawn in tributaries to Lake Erie (Borden and Stepien 2006 ; Borden 2008). In this study we further validate this claim by analyzing 221 individuals from several lake and tributary sites using 7 microsatellite loci. We also provide evidence that suggests there may be two different types of tributary spawning bass based on an isolation by distance statistical test. Our data indicate that there are bass that spawn for multiple years in one stream and there are others that spawn opportunistically in small tributaries throughout the lake. Based on these genetic data it has been hypothesized that these genetic differences are the result of fidelity to different spawning sites (Borden and Stepien 2006; Borden 2008). To test this hypothesis we used radio telemetry to study bass movement patterns during two consecutive spawning seasons. Bass in our study displayed a high degree of fidelity to their spawning location during both spawning seasons with 50 to 85 percent return frequencies at each location. Our results corroborate well with the genetic data published in previous studies and cumulatively these data suggests there are at least two different life histories bass display in Lake Erie.