Keywords
Molecular ecology; Population genetics; Galápagos
Abstract
The Galápagos Islands, a UNESCO World Heritage Site and a biodiversity hotspot with high levels of endemism, is home to over 440 species of fishes. Marine conditions across the Archipelago are greatly influenced by ocean currents in the region. The Pacific Equatorial Undercurrent, South Equatorial Current, and the Humboldt Current deliver waters rich in nutrients across the three major regions within the Galápagos (central, north, and west). These conditions create a dynamic environment close to the equator, enabling diverse species to thrive in distinct parts of the Galápagos. Despite the rich biodiversity in the region and diverse oceanographic conditions, there has been limited research examining the genetic connectivity of marine populations across the Galápagos Islands. The objective of this study is to examine population structure in two fish species located across the three regions of the Galápagos: the southern white tail major (Stegastes beebei) and the blacktip cardinalfish (Apogon atradorsatus). These species differ in reproductive strategies and the length of their dispersive larval stage, offering a unique opportunity to study the interplay between ecological conditions, reproductive strategies, and population dynamics. Here I used restriction-site Associated DNA sequencing on 45 individuals from each species across the three major regions. I analyzed both neutral and potentially selective loci to provide valuable insight into how species adapt to their environment, which have important implications for conservation and fisheries management in the Galápagos. While I did not detect population structure in S. beebei, I did detect low levels of structure in A. atradorsatus when outlier loci were considered. These data indicate that regional differences and limited larval stage contribute to genetic structure across the Galápagos.
Thesis Completion Year
2025
Thesis Completion Semester
Summer
Thesis Chair
Gaither, Michelle R.
College
College of Sciences
Department
Biology
Thesis Discipline
Biology
Language
English
Access Status
Open Access
Length of Campus Access
None
Campus Location
Orlando (Main) Campus
STARS Citation
Quach, Hillary, "A Tail of Two Fishes: Exploring Population Structure in Two Species of Fishes Across the Galápagos Islands" (2025). Honors Undergraduate Theses. 379.
https://stars.library.ucf.edu/hut2024/379
Rights Statement
