Physiological Diversity of Centrarchid Fishes

The focus of my dissertation research was assessing the inter- and intra-specific physiological diversity of centrarchid fishes (freshwater sunfish), and examining how this variation shapes their conservation needs. To evaluate inter-specific physiological diversity, an integrated field and laboratory study was used to quantify the energetic costs (intensity and duration) and physiological correlates (cardiovascular performance) of parental care in six syntopic centrarchids. Parental care energetics varied substantially among the six species, with smaller species providing more intense care than larger ones. Males that were engaged in providing parental care had higher resting cardiovascular parameters and recovered more rapidly from exercise than did conspecific males that were not engaged in parental care. Species that modulated cardiac output principally by changing heart rate were also the species that invested the most total energy in parental care. To evaluate intra-specific physiological diversity, a series of genetically distinct stocks of largemouth bass collected from different regions of the upper midwestern United States were used to assess the physiological and energetic bases of adaptation to different climatic conditions. Locally adapted fish had superior (i.e., more efficient) physiological performance than non-local stocks or the resulting interstock hybrids, indicating that physiological differences can exist even at small spatial scales, and/or among groups with apparently close genetic relatedness. A second assessment of intra-specific variation evaluated the evolutionary consequences of selection through angling. Comparing two distinct lines of largemouth bass differentially selected for high and low vulnerability to angling over several generations, the more vulnerable line had higher metabolic rates and was more aggressive in defending broods. These aggressive individuals required greater food intake to compensate for the higher metabolic rates, likely leading to more time foraging and their increased angling vulnerability. Collectively, the findings of these individual studies provide strong evidence for biologically meaningful physiological diversity at the individual, stock, and species levels that needs to be considered in the development of conservation and management strategies.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2015

Author dc:creator

• Cooke, Steven James

Contributors dc:contributor

• Philipp, David P.
• Wahl, David H.

• Biology, Animal Physiology

Language dc:language

eng

Identifier

(MiAaPQ)AAI3069984

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/87875