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Thesis Examination: MSc Student Jenna Fleet

Wed. Aug. 11 11:00 AM - Wed. Aug. 11 01:00 PM
Contact: Dylan Jones
Location: Zoom

Jenna Fleet - MSc Student in Bioscience, Technology, and Public Policy 

Transgenerational acclimation and phenotypic variation in a freshwater fish species exposed to near-future carbon dioxide levels

Thesis Exam Chair: Dr. Jens Franck, Biology Department Chair

Abstract: The amount of dissolved carbon dioxide (CO2) and the acidity of aquatic ecosystems is increasing and can have considerable aversive effects on fish physiology and behaviour. In my thesis, freshwater Japanese Medaka (Oryzias latipes) were used to investigate the influence of behavioural phenotypic variation and differences in time of exposure (generational) on biological responses to elevated CO2. Medaka were divided into ‘responsive’ and ‘non-responsive’ groups based on behavioural differences from the population mean and exposed to various generational CO2 exposures through three generations (parental, filial generation one and two). Differences in body condition (size, weight and length), behaviour (total distance moved, time spent in the outer zone of the behavioural arena, and swimming direction), reproductive (number of eggs, size of eggs, and survival to hatch) performance, and the relative abundance of various mRNA transcripts in whole brain tissue of fish was measured across these three generations. Behavioural phenotypes influenced reproduction for P and F2 generation fish, and growth for F1 and F2 fish; suggesting that intraspecific variation in behavioural phenotypes may influence how medaka respond to elevated CO2. Multigenerational and transgenerational exposure to elevated CO2 affected reproductive, growth, and relative mRNA abundance and the results suggest that generational exposure can influence responses to environmental conditions and that multigenerational acclimation may be possible for some measures. The results of this research contribute to filling a current gap of knowledge in understanding how freshwater fish will respond to future conditions over an ecologically relevant time scale which can contribute to informed decisions on freshwater ecosystem management. 

To register as an audience member, please email Dylan Jones at d.jones@uwinnipeg.ca