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Open Access Knowledge and Scholarship

Date of Award

12-2025

Culminating Project Type

Thesis

Styleguide

apa

Degree Name

Special Studies: M.S.

Department

Biology

College

College of Science and Engineering

First Advisor

Matthew Davis

Second Advisor

Sarah Gibson

Third Advisor

Matthew Julius

Creative Commons License

Creative Commons License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License.

Keywords and Subject Headings

Fishes, Deep-sea, Dragonfishes, Evolution, Biogeography, Marine

Abstract

Dragonfishes and their allies (Stomiiformes) represent a diverse lineage of deep-sea pelagic fishes that have evolved distinctive adaptations, including bioluminescence, for life in the open ocean. This study investigates the evolutionary relationships and global biogeographic patterns of Stomiiformes by integrating species occurrence data with a time-calibrated phylogenomic framework.

Occurrence records representing all 464 recognized species of Stomiiformes were obtained from the Global Biodiversity Information Facility (GBIF) and mapped in QGIS to visualize global distributions. Each species was assigned to pelagic realms of endemism defined by Costello et al. (2017) to examine how modern ranges align with patterns of pelagic biodiversity. Most stomiiform lineages occur in the Mid-Atlantic, Pacific, and Indian Oceans, with repeated but limited extensions into colder Arctic and Southern Ocean realms.

To examine these patterns in the context of time, we reconstructed a phylogeny from ultraconserved element (UCE) data, time-calibrated it, and used the resulting tree to estimate divergence times and reconstruct ancestral areas. The results support the monophyly of Stomiiformes and indicate that the group originated in the Tethys Sea during the Late Cretaceous, followed by diversification across global pelagic environments. Multiple independent invasions into colder waters occurred as ocean temperatures cooled through the Cenozoic, with the barbeled dragonfishes (Stomiidae) showing the greatest ecological breadth and diversification. Together, these results clarify the temporal and spatial history of Stomiiformes and highlight how changing ocean conditions have shaped their modern distributions.

Comments/Acknowledgements

Acknowledgements:

I am deeply grateful to my family and my partner for their unwavering support, encouragement, and patience throughout this journey. Their belief in me and the stability they provided made it possible for me to pursue graduate school at this time. I would like to thank my advisor, Dr. Matthew Davis, my committee members, Dr. Sarah Gibson and Dr. Matthew Julius, and my lab collaborators Meghan Larson, Elizabeth Favor, Natalie Swearingen, and Aimee Hruska, for their advice, support, and feedback. I would also like to thank external collaborators on this project, including Dr. Wm. Leo Smith (University of Kansas).

I would like to thank St. Cloud State University for funding through the Student Research Mentor/Mentee Collaboration Grant. I would also like to thank St. Cloud State University for the opportunity to work as a graduate teaching assistant, which, along with tuition support, made it possible for me to pursue graduate school. Additional funding for this work was provided by the Hellervik Prize (SCSU award to M.P. Davis). I would also like to thank the American Society of Ichthyologists and Herpetologists for supporting my professional development through the Raney Award and providing support to attend the Joint Meeting of Ichthyologists and Herpetologists.

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