The Repository @ St. Cloud State

Open Access Knowledge and Scholarship

Date of Award


Culminating Project Type


Degree Name

Biological Sciences - Ecology and Natural Resources: M.S.




College of Science and Engineering

First Advisor

Matthew Davis

Second Advisor

Heiko Schoenfuss

Third Advisor

Matthew Tornow

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

Deep sea, Anatomy, Systematics


To date, no study has investigated how many independent evolutions of fangs have occurred across ray-finned fishes. This research addresses this question by focusing on the evolution of fangs across a diversity of marine habitats in the Lizardfishes (Aulopiformes), and then investigating the evolution of fangs across ray-finned fishes (Actinopterygii). Lizardfishes are a diverse order of fishes (~236 species) that are observed to have fang-like teeth and occupy a variety of marine habitats. A taxonomic review of lizardfish specimens representing 35 of 44 genera were examined for the presence of fangs. In addition to assessing the presence of fangs, lizardfish habitat was also evaluated to examine if there is a correlation between fang presence and habitat. I estimated the character evolution of fang presence and habitat across a previously published phylogeny of lizardfish relationships to examine evolutionary patterns. I identified that fangs have independently evolved three times across the lizardfishes. There is also a correlation between the evolution of fangs in lizardfishes and habitat with fangs evolving more frequently in deep-sea pelagic habitats. To further investigate the evolution of fangs, I expanded my research to include a robust hypothesis of relationships among families of ray-finned fishes. Using previously published genetic data, I inferred a phylogeny of 315 species representing 211 families of ray-finned fishes. I again utilized ancestral character-state reconstructions to examine patterns of fang evolution across ray-finned fishes. The results of my analyses indicates that there have been at least 38 independent evolutions of fangs across ray-finned fishes. Generally in families that evolved fangs, when the majority of the species diversity possess fangs they are found in pelagic environments.


I would like to thank the following people and institutions for providing specimens used in this study: K. Hartel and A. Williston (MCZ, Cambridge, Massachusetts), C. McMahan, K. Swagel, and S. Mochel (FMNH, Chicago, Illinois), R. Feeney (LACMNH, Los Angeles, California), J. Williams and G.D. Johnson (USNM, Washington, DC) J. McClain (BMNH, Kensington, London), B. Frable and H.J. Walker (SIO, San Diego, California), D. Catania (CAS/ SU, San Fransisco, California), E. Hilton (VIMS, Gloucester Point, Virginia), J. Sparks (AMNH, New York, New York), and R. Robins (CI, Gainesville, Florida). Funding for this work was provided by the St. Cloud State Office of Research and Sponsored Programs and the National Science Foundation (DEB 1258141, 1543654). I would also like to thank St. Cloud State University for support for the use of facilities and equipment, including the Integrated Science and Engineering Laboratory Facility. I would also like to thank my committee (H. Schoenfuss, M. Tornow) for comments and suggestions on this work. I also thank my advisor Matthew Davis and lab mate Rene Martin for their many comments, suggestions, and conversations about fishes. Finally, I thank my parents for their continued support of my academic career.



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