Olfactory imprinting is one mechanism thought to guide natal stream homing and facilitate natal site fidelity, an important reproductive strategy that leads to localized adaptations in genetically distinct fish populations. My thesis investigates olfactory imprinting during early ontogeny in lake sturgeon and the potential role of stream specific amino acid profiles as the guiding odors in olfactory imprinting and stream discrimination by lake sturgeon. In Chapter 1, I test the hypothesis that olfactory memory formation occurs in early development and provide behavioral evidence of olfactory imprinting during the free-embryo and exogenous feeding life stages in lake sturgeon. In Chapter 2, I describe the temporal and spatial variability of amino acid profiles in Great Lakes tributaries and discuss the potential utility and limitations for amino acids to function as odorants guiding olfactory imprinting in lake sturgeon in the Great Lakes. In this chapter, I also provide empirical evidence for olfactory memory formation to artificial amino acid profiles during early ontogeny and suggest further studies to see unequivocal evidence on whether lake sturgeon discriminate stream specific amino acid profiles. This thesis supports the use of streamside rearing facilities for exposing lake sturgeon to natal stream odors during early life stages.
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