TIMING OF SPAWNING IN LARGEMOUTH BASS - IMPLICATIONS OF AN INDIVIDUAL-BASED MODEL

Authored by AS Trebitz

Date Published: 1991

DOI: 10.1016/0304-3800(91)90178-4

Sponsors: United States Department of Energy (DOE) Electric Power Research Institute (EPRI) Martin Marietta Systems Inc

Platforms: No platforms listed

Model Documentation: Other Narrative Flow charts Mathematical description

Model Code URLs: Model code not found

Abstract

Timing of reproduction can help adjust the lifecycle of a species to coincide with biotic and abiotic conditions favorable for the growth and survival of its young. In fishes, factors related to the selection of spawning time include temperature regime, abundance and distribution of prey, and density-dependent feedbacks between population size, growth, survival, and reproduction. An individual-based model for young-of-year largemouth bass (Micropterus salmoides) is presented. The model is then used to explore how these factors interact to determine optimal spawning time, defined here as that spawning time for which the total biomass of a cohort of bass at one year of age is maximized. When food intake per individual was assumed to be independent of population size, a broad peak in total cohort biomass occurred at intermediate spawning temperatures. With the addition of density dependence in food intake, a nearly constant total biomass was attained across a range of prescribed spawning temperatures. When largemouth bass spawned at different times within a year competed for a common food resource, those spawned earliest tended to produce the greatest total biomass. Fish representing a variety of spawning strategies were able to coexist over 15 simulated generations, however, because the number of offspring produced by any one strategy was limiting by the availability of prey of suitable size. Simulation results argue that recruitment success should not be assessed until well after young begin feeding, as density-dependent factors will determine the relative success of cohorts that survive adverse environmental conditions.
Tags
growth Prey selection Planktivorous fish Reproductive success Smallmouth bass Body size Micropterus-salmoides Lepomis-macrochirus 1st-year survival Apparent size