Adapting to salinity: The effects of salinity on population structure and offspring survival in Lucania parva
type: CreativeWork
description: Adaptation to salinity is an important driving force in the evolution in teleost fishes. Some speciose groups such as minnows and characids are found predominantly in fresh water, while other groups such as tunas and wrasses are found predominantly in marine habitats. Euryhaline groups, such as killifish, contain freshwater species, marine species, and species that can occur in fresh, brackish, and marine conditions. These groups are powerful systems for studying adaptation to salinity as they allow for the comparison of close relatives who differ in salinity tolerance. In chapter 1, I review the biology of Lucania killifish. Lucania contains three species, one of which is a freshwater species (L. goodei) and another of which is euryhaline (L. parva). A third species (L. interioris) is endemic to a small region in Mexico and is not considered in this thesis. Previous studies on L. goodei and L. parva suggest that salinity has dramatic effects on life-history, ecology, physiology, and genetic differentiation at the between-species level. Upon salinity transfer, the two species differ in gene expression in critical osmoregulatory genes. An examination of FST outliers suggests that the two species differ in many genes related to osmoregulation, but that they also possess high levels of differentiation between genes involved in reproduction and spermatogenesis. Within L. parva, preliminary work indicated that freshwater-saltwater population pairs also possessed elevated levels of differentiation in loci related to osmoregulation. In chapter 2, I used RAD-Seq data from 10 populations across Florida to examine the levels of population structure between freshwater and saltwater populations and the effects of distance on population-wide FST. Here, I found good evidence that differences in salinity increase FST beyond what would be expected from the effects of distance alone. In chapter 3, I describe a laboratory experiment that tests for both local adaptation and for matern…
abstract: Adaptation to salinity is an important driving force in the evolution in teleost fishes. Some speciose groups such as minnows and characids are found predominantly in fresh water, while other groups such as tunas and wrasses are found predominantly in marine habitats. Euryhaline groups, such as killifish, contain freshwater species, marine species, and species that can occur in fresh, brackish, and marine conditions. These groups are powerful systems for studying adaptation to salinity as they allow for the comparison of close relatives who differ in salinity tolerance. In chapter 1, I review the biology of Lucania killifish. Lucania contains three species, one of which is a freshwater species (L. goodei) and another of which is euryhaline (L. parva). A third species (L. interioris) is endemic to a small region in Mexico and is not considered in this thesis. Previous studies on L. goodei and L. parva suggest that salinity has dramatic effects on life-history, ecology, physiology, and genetic differentiation at the between-species level. Upon salinity transfer, the two species differ in gene expression in critical osmoregulatory genes. An examination of FST outliers suggests that the two species differ in many genes related to osmoregulation, but that they also possess high levels of differentiation between genes involved in reproduction and spermatogenesis. Within L. parva, preliminary work indicated that freshwater-saltwater population pairs also possessed elevated levels of differentiation in loci related to osmoregulation. In chapter 2, I used RAD-Seq data from 10 populations across Florida to examine the levels of population structure between freshwater and saltwater populations and the effects of distance on population-wide FST. Here, I found good evidence that differences in salinity increase FST beyond what would be expected from the effects of distance alone. In chapter 3, I describe a laboratory experiment that tests for both local adaptation and for matern…
author: McDaniel, Lauren Kelley
language: en
keywords: speciation, local adaptation, salinity, osmoregulation
date published: 2020-10-07T21:00:05Z
date modified: 2026-07-22T22:24:48Z
provider: University of Illinois - Urbana-Champaign
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: University of Illinois at Urbana-Champaign

PropertyValue
property ID: Handle
value: http://hdl.handle.net/2142/108521