Graduation Date

Summer 2018

Document Type

Thesis

Program

Master of Science degree with a major in Natural Resources, option Fisheries

Committee Chair Name

Dr. Andrew Kinziger

Committee Chair Affiliation

HSU Faculty or Staff

Second Committee Member Name

Dr. Darren Ward

Second Committee Member Affiliation

HSU Faculty or Staff

Third Committee Member Name

Dr. Andre Buchheister

Third Committee Member Affiliation

HSU Faculty or Staff

Subject Categories

Fisheries

Abstract

Surveys of genetic variation have improved our understanding of the relationship between fitness-related phenotypes and their underlying genetic basis. However, how this information can be used to inform conservation has been unclear in many cases. The objective of this study was to combine next-generation genetic sequencing with traditional ecological knowledge to evaluate imperiled anadromous Pacific lamprey (Entosphenus tridentatus) and apply the findings to conservation in the context of resolving Native American traditional food security issues. In the Klamath River of California, a previously identified Pacific lamprey ocean-maturing ecotype was distinguished by a relatively advanced maturity of female fish (e.g., large egg mass) upon freshwater entry compared to a relatively immature river-maturing ecotype. However, relative run-timing and the genetic basis of this ecotypic differentiation was not known. I collected 219 returning adult Pacific lamprey at-entry to the Klamath River over a 12-month period, genotyped them at 308 neutral and adaptive single nucleotide polymorphism (SNP) loci, and recorded morphological traits, including egg mass as an indicator of female sexual maturity. The onset for freshwater migration for the ocean-maturing ecotype was predominantly the winter whereas the river-maturing ecotype entered during all seasons and a genetic basis of the ecotype diversity was revealed. Genotype-phenotype association mapping identified sixteen SNPs significantly associated to egg mass forming two groups of linked loci and ten other SNPs significantly associated to total length. A duplicate dominant epistasis inheritance model best supported the ocean- and river-maturing ecotypes, accurately predicting ecotype in 83% of the samples. The adaptive genetic variation revealed is useful for conservation planning as it indicates that the river-maturing ecotype carries standing genetic variation capable of producing both ecotypes (e.g., both heterozygous and homozygous individuals), while the ocean-maturing ecotype is almost exclusively homozygous. An ecological application of these molecular findings is that when assessing stream restoration projects, the river-maturing ecotypes could perhaps be prioritized as they contain the genetic diversity capable of producing both ecotypes (i.e., heterozygosity), whereas the ocean-maturing ecotypes do not. I recommend distinguishing the river-maturing and ocean-maturing ecotypes of Pacific lamprey by adopting the names ke’ween (lamprey “eel”) and tewol (ocean), respectively, using terms from the Yurok language, in recognition of the importance of Pacific lamprey to Pacific Northwest fishing tribes.

Citation Style

APA

Included in

Genetics Commons

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