Culminating Project Title
Date of Award
Culminating Project Type
Biological Sciences - Ecology and Natural Resources: M.S.
College of Science and Engineering
Creative Commons License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License.
Keywords and Subject Headings
Deepsea, Bioluminescence, Phylogenomics, Morphology, Systematics, Taxonomic
Stomiiformes (dragonfishes and their allies) are a diverse radiation of ray-finned fishes found in pelagic deep-sea habitats. With 305 species, the family Stomiidae (dragonfishes) are the most species-rich lineage of stomiiform fishes. They are diagnosed from other stomiiforms, in part, by the possession of a bioluminescent chin barbel, and they are also recognized by their elongate bodies with ventral light organs and enlarged teeth. Previous evolutionary studies examining the relationships among stomiiform fishes have been based on morphological characters or molecular sequence data, and the results of these studies have recovered conflicting hypotheses of relationships. In this study, I investigate the relationships among the dragonfishes and present a novel hypothesis of evolutionary relationships for the family that is based on genome-scale data that includes both ultraconserved elements (UCEs) and additional proteincoding gene fragments. Our new family-level hypothesis includes 25 of the 27 currently recognized stomiid genera and all previously recognized stomiid subfamilies. Our resulting phylogenies were incongruent with the prevailing classification of stomiids based on morphological data, and it rendered several of the currently recognized subfamilies as para- or polyphyletic. The subfamilies Chauliodontinae, Stomiinae, Idiacanthinae, and Malacosteinae were resolved as monophyletic while Astronesthinae was inferred as paraphyletic and Melanostominae were inferred as polyphyletic. Herein, we present a revised classification of the Stomiidae that reflects our recovered relationships and is based exclusively on monophyletic lineages. Our revised classification integrates previously published morphological data to aid in the diagnoses of new, resurrected, and modified stomiid subfamilies. In addition to the revision of stomiid taxa, we investigate the evolution of bioluminescent barbel structures across dragonfishes. These barbels are found on the base of the urohyal bone with high variation of anatomical features along the stem and tip, containing luminous tissues. This structure is hypothesized to be used for prey attraction and communication. Anatomical structures of the barbels can range from simple and elongate stems to the possession of complex structures. These structures include bulbs and bulblets, filaments, and branching networks, as well as flattened and leaf-like structures. The revised Stomiidae phylogeny is used to infer the character evolution of anatomical variation in this light producing appendage. Our results indicate multiple evolutions of barbel modifications on the stem, tip, and sexual dimorphism.
DeArmon, Emily, "Dragons of the Deep: Evolutionary Phylogenomic Relationships of Stomiidae (Dragonfishes) and the Evolution of Their Bioluminescent Barbels" (2019). Culminating Projects in Biology. 40.
Available for download on Monday, April 25, 2022