Seasonal Differences of Pacific Herring (Clupea pallasii) Embryo and Larval Metrics are Small, but Developmental Stage Drives Significant Proteomic and Physiological Variation.

Author

Ariel Elizabeth Shiley, Western Washington UniversityFollow

Date of Award

Summer 2025

Document Type

Masters Thesis

Department or Program Affiliation

Environmental Science

Degree Name

Master of Science (MS)

Department

Environmental Sciences

First Advisor

Love, Brooke

Second Advisor

Timmins-Schiffman, Emma B.

Third Advisor

Cooper, W. James, 1969-

Fourth Advisor

Sobocinski, Kathryn L.

Abstract

Spawning biomass estimates are variable from year to year for the 21 recognized spawning populations of Pacific herring in the Salish Sea. The population decline of the late spawning Cherry Point population is notable and motivated this investigation of seasonal differences in larval morphology and lipid provisioning of embryos and larvae. Proteomic analysis was performed to identify mechanisms of observed differences and uncover additional subtle changes in physiological state. Embryos were collected by the Washington Department of Fish and Wildlife and cultured at in-situ temperature conditions to measure potential differences in total hatch and morphology across the season. We compared cohorts from the Semiahmoo Bay population collected in February, March, and April of 2023 and 2024. No spawn was detected in either target late spawning populations (Elliot Bay, Cherry Point). While significant temperature differences were expected across the seasonal gradient, a lack of late spawning samples resulted in a small temperature range between 6 and 10°C. Cohorts through the spawning season were similar in most measures, including total hatch, lipid provisioning, and yolk sac size at hatch. LIMMA identified 32 differentially abundant proteins out of over 2000 total proteins in the early and late-season embryos, demonstrating that the proteomes of early and late season embryos were broadly similar. The low number of differentially abundant proteins supports the observed similarity between cohorts seen in other measures. Development did have significant impacts on yolk sac area and the proteome of embryos. Image analysis revealed a progressive decrease in normalized yolk sac area over the course of embryogenesis, consistent with expected developmental patterns. A total of 1,586 proteins were differentially abundant between embryos at developmental stages B and H. Later stage embryos exhibited an increased abundance of proteins associated with protein homeostasis, cell development, and lipid metabolism. Development of these methods and ongoing analysis of these data should help guide hypothesis testing regarding the resilience of embryos to environmental conditions as they develop. Overall, these observations suggest that Pacific herring embryos can cope with the small range of temperature variability observed (between 6 and 10°C) without significant molecular or physiological changes, and significant changes occur in embryos throughout development.

Type

Text

Keywords

Pacific herring, Proteomics, Lipids, Hatching, Herring, Seasonal Variability, Semiahmoo Bay

Publisher

Western Washington University

OCLC Number

1531273386

Format

application/pdf

Genre/Form

masters theses

Language

English

Rights

Copying of this document in whole or in part is allowable only for scholarly purposes. It is understood, however, that any copying or publication of this document for commercial purposes, or for financial gain, shall not be allowed without the author’s written permission.

Recommended Citation

Shiley, Ariel Elizabeth, "Seasonal Differences of Pacific Herring (Clupea pallasii) Embryo and Larval Metrics are Small, but Developmental Stage Drives Significant Proteomic and Physiological Variation." (2025). WWU Graduate School Collection. 1445.
https://cedar.wwu.edu/wwuet/1445