College of Forest Resources Publications and Scholarship
ORCID
Fast: kmf160@msstate.edu; ORCID: https://orcid.org/0000-0001-5476-5330
Hundt: hundt002@umn.edu; ORCID: https://orcid.org/0000-0001-5567-3905
Alley: zalley2509@gmail.com; ORCID: https://orcid.org/0000-0002-8448-6583
Sandel: mws297@msstate.edu; ORCID: https://orcid.org/0000-0001-9083-9202
Abstract
The Central Highlands ecoregion of the eastern United States represents a hotspot of freshwater biodiversity, with replicated patterns of vicariant speciation east and west of the Mississippi River. Previous phylogeographic investigation of the studfishes (Fundulus subgenus Fundulus) revealed evidence for vicariant speciation in the Central Highlands, but data were limited to a small number of gene sequences generated with Sanger sequencing. We used double digest restriction-site associated DNA sequencing (ddRADseq) to improve resolution of phylogeographic patterns and better characterize population genetic variation. Our sample design included individuals from the Fundulus catenatus species group (F. catenatus, F. bifax, and F. stellifer) and two outgroup taxa (F. julisia and F. rathbuni). Phylogenetic analyses support a monophyletic F. catenatus complex and a sister relationship with Mobile Basin studfishes (F. bifax and F. stellifer). Population genomics and species delimitation tests provide evidence for three species-level subdivisions of F. catenatus. We describe F. catenatus as limited to the Tennessee River and its drainages, F. caddo in the Ouachita Highlands, and F. cryptocatenatus occupying the remainder of the range. Modally, F. catenatus was characterized by fewer left pectoral rays (16 vs. 17). Fundulus caddo had modally fewer anal rays (15 vs. 16) and lateral scale rows (13 vs. 14). Fundulus cryptocatenatus was characterized by modally higher dorsal rays (15 vs. 14) and fewer caudal rays (16 vs. 17). The geographic distribution is likely the result of multiple pre-Pleistocene vicariance events congruent with the Central Highlands Vicariance Hypothesis as well as separate, possibly subsequent, dispersal events. Overall, results of this study corroborate previous evidence for a complex biogeographic history of taxa endemic to rivers of the Central Highlands ecoregion. The improved resolution of genomic variation among studfish populations will guide future studies of morphological variation and will improve conservation plans for rare and endemic taxa in a freshwater biodiversity hotspot.
DOI
https://doi.org/10.54718/KIDX5222
Publication Date
2024
College
College of Forest Resources
Department
Department of Wildlife, Fisheries and Aquaculture
Keywords
Biogeography, genomics, ddRADseq, endemism
Disciplines
Bioinformatics | Evolution | Forest Sciences | Genetics and Genomics
Recommended Citation
Fast, Kayla M.; Hundt, Peter J.; Alley, Zachariah D.; and Sandel, Michael W., "Phylogenomic Species Delimitation of Studfishes (Fundulidae: Fundulus): Evidence for Cryptic Species in Agreement with the Central Highlands Vicariance Hypothesis" (2024). College of Forest Resources Publications and Scholarship. 28.
https://scholarsjunction.msstate.edu/cfr-publications/28
Included in
Bioinformatics Commons, Evolution Commons, Forest Sciences Commons, Genetics and Genomics Commons
Comments
A combination of DArT complexity reduction with sequencing on the Next Generation Sequencing platforms. Represents combined marker discovery and genotyping for SNP and SilicoDArTs (Presence/Absence of DNA fragments in genomic representations). Approximately 50,000 DNA fragments from DArT representations are assayed for polymorphism.