Patterns and processes of life history variation in the smallmouth bass, Micropterus dolomieu.
Published: 2005
Language: eng
Number of pages: 224
Description: This research explores the degree and causes of life history variation in the smallmouth bass, Micropterus dolomieu. Smallmouth bass are an interesting study species for exploring life history variation for two main reasons: (i) many populations are in various stages of colonization thereby allowing characterization of life history dynamics as a population adapts to a new environment; (ii) they show paternal care, the presence of which may modify patterns of life history response. Variability is examined over a broad scale of geographically diverse populations, between adjacent populations, and temporally within populations. Results indicate that there is a large degree of variation in somatic growth and maturation among smallmouth bass populations and that climate, food availability, and mortality are important drivers of this variation. A significant amount of the among-population differences represent a combination of plastic responses and genetic adaptation to these three forces. Among populations spread over the present North American range of the species, there is a positive relationship between temperature and early growth but the association weakens in non-native populations. On a local scale, food availability and lack of ontogenetic diet shifting appear to have driven much of the phenotypic divergence in growth and maturation between two populations introduced from a common source a century ago. Finally, the results of an individual-based model show that selective mortality can influence population dynamics, somatic growth, and evolution of maturation in a short time span. However, the addition of survival functions associated with parental care reduces the magnitude of evolutionary response. This study underscores the importance of considering population life history as dynamic and capable of showing rapid plastic and/or genetic responses to both natural and human forces.
Notes: Source: Dissertation Abstracts International, Volume: 66-10, Section: B, page: 5194.

Thesis (Ph.D.)--University of Toronto, 2005.

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