—Fish maturity status, sex ratio, and age and size at first maturity are important parameters in population assessments and life history studies. In most empirical studies of these variables, fish are sacrificed and dissected to obtain data. However, maturity status and the sex of mature individuals can be determined by inserting an endoscope through a small incision in the body cavity wall and...

Models based on simple air temperature–water temperature relationships have been useful in highlighting potential threats to coldwater-dependent species such as Brook Trout Salvelinus fontinalis by predicting major losses of habitat and substantial reductions in geographic distribution. However, spatial variability in the relationship between changes in air temperature to changes in water tempe...

-To measure the changes in substrate composition produced by spawning brook trout Salvefinus fontinalis, we collected 187 freeze-core samples, both before and after spawning, from egg pockets, inside redds but excluding egg pockets, and outside redds. In the upper strata of reddassociated samples, we found that the proportions of particles 0.85-1.70,0.425-0.85,0.2 12-0.425, and less than 0.212 ...

—Retention and readability of small (2.5 3 1.0 3 0.1-mm) and large (3.0 3 1.5 3 0.1mm) visible implant (VI) tags were compared among different size-classes (211–470 mm total length, TL) of hatchery brook trout Salvelinus fontinalis. Among smaller size-groups (,400 mm TL), retention of large tags (63–86%) 100 d after tagging was less than retention of small tags (89–97%). Overall retention of la...

Distinct morphological variation is often associated with variation in life histories within and among populations of both plants and animals. In this study, we examined the heritability of morphology in three hatchery strains of brook trout (Salvelinus fontinalis), which were historically or are currently used for stocking and supplementation of both migratory and resident ecotypes in the uppe...

iii ACKNOWLEDGEMENTS I want to thank my advisor, Andrew Whiteley, for all of his encouragement and support throughout my graduate studies: for taking me on as a student, supporting me as a research assistant, helping me understand the concepts described in this thesis and patiently guiding me through this research. I also want to express my sincere thanks to my committee members Ben Letcher and...