Stable Isotopes in the Eye Lenses of Doryteuthis plei: Exploring Natal Origins and Migratory Patterns in the Eastern Gulf of Mexico

Author

Brenna A. Meath, University of South FloridaFollow

Graduation Year

2018

Document Type

Thesis

Degree

M.S.

Degree Name

Master of Science (M.S.)

Degree Granting Department

Marine Science

Major Professor

Heather L. Judkins, Ph.D.

Co-Major Professor

Ernst B. Peebles, Ph.D.

Committee Member

Brad A. Seibel, Ph.D.

Keywords

crystallin proteins, arrow squid, life history, spawning patterns

Abstract

Stable isotope analysis is an emerging tool to examine trophic pathways and migratory patterns of marine organisms. Squid are widely distributed in coastal and deep water regions of the Gulf of Mexico. Stable isotope ratios of carbon and nitrogen found within cephalopod tissues can provide information on both trophic level and habitat of their food sources. More recently, ontogenetic changes in stable isotope ratios within squid eye lenses have been documented. Concentric layers of crystallin proteins are added to the lens as the squid ages; the center of the lens contains the oldest layer and the youngest layers are on the outermost surface. The crystallin proteins are rich in carbon and nitrogen, providing suitable sources for isotopic analysis of both δ¹⁵N and δ¹³C. Doryteuthis plei is a common inshore squid in coastal waters of the western Atlantic region. This study identifies the geographic movements of D. plei in the eastern Gulf of Mexico using changes in isotope ratios in eye-lens layers. Isotopic analyses suggest that these squid begin their lives in the deep chlorophyll maximum of the outer shelf and move inshore as they age.

Scholar Commons Citation

Meath, Brenna A., "Stable Isotopes in the Eye Lenses of Doryteuthis plei: Exploring Natal Origins and Migratory Patterns in the Eastern Gulf of Mexico" (2017). USF Tampa Graduate Theses and Dissertations.
https://digitalcommons.usf.edu/etd/7063