Open Access. Powered by Scholars. Published by Universities.®
- Keyword
-
- Hybridization (3)
- Conservation (2)
- Ecology (2)
- Evolution (2)
- Hybrid zones (2)
-
- Management (2)
- Percina (2)
- Spawning (2)
- Achariaceae (1)
- Ag (1)
- Aquatic ecology (1)
- Behavior (1)
- Body size (1)
- Character displacement (1)
- Chaulmoogra oil (1)
- Climate Change (1)
- Coexistence (1)
- Competition (1)
- Developmental plasticity (1)
- Distribution (1)
- Estuary (1)
- Flacourtiaceae (1)
- Fulton’s condition index (1)
- Fundulus (1)
- Fundulus notatus (1)
- Fundulus notatus species complex (1)
- Fundulus olivaceus (1)
- Gambusia affinis (1)
- Genetic techniques (1)
- Geometric morphometric (1)
Articles 1 - 16 of 16
Full-Text Articles in Life Sciences
Variations In Thermoregulation Strategies Of Northern And Southern Populations Of Mischocyttarus Mexicanus, Taylor Guild
Variations In Thermoregulation Strategies Of Northern And Southern Populations Of Mischocyttarus Mexicanus, Taylor Guild
Honors Theses
Mischocyttarus mexicanus is a species of eusocial paper wasp that is found across much of the Southeastern coastal region of the United States. Contrasting wintering strategies have been seen in northern versus southern populations. Anecdotally, northern populations overwinter by clustering on top of palmetto fronds, their preferred nesting substrate, in a sort of "taco" shape, while southern populations stand on their nests that hang on the underside of the palmetto frond throughout the year. I tested three hypotheses related to the adaptive value of northern over-frond clustering behavior: 1) Over-frond clustering is thermoregulation related, meaning it would be temperature driven. …
Analysis Of Ecological Tradeoffs Between Congeneric Shrimp In Coastal Mississippi Waters, Baylor K. Lynch
Analysis Of Ecological Tradeoffs Between Congeneric Shrimp In Coastal Mississippi Waters, Baylor K. Lynch
Honors Theses
Palaemonidae is an ecologically important and abundant family of shrimp that link the benthos to many estuarine food webs. Palaemon pugio and Palaemon vulgaris regularly co-occur along estuarine edge habitats despite previous studies suggesting different preferred sediment types and salinity regimes. The objective was to determine if competition is occurring between the congeners by comparing their relative abundance and assessing isotope niche space along an estuarine gradient. I seasonally sampled various edge habitats at four sites throughout Biloxi Bay, MS, using fyke nets fished over a tidal cycle from November 2020 to November 2021. Collected organisms were identified to the …
Reproductive Timing In Percina Aurora And Other Percina Species In The Pascagoula River Watershed, Malia Davidson
Reproductive Timing In Percina Aurora And Other Percina Species In The Pascagoula River Watershed, Malia Davidson
Honors Theses
The Southeastern United States is home to high levels of aquatic biodiversity and was recently named one of the Earth’s biodiversity hotspots. Within this region, growing human populations continue to place pressure on aquatic ecosystems and the resident species. Darters (Percidae: Percina) represent a large proportion of the freshwater fish diversity in the region. However, for some species the fundamentals of age, growth, reproductive timing and effort, and ecology remain poorly understood. That said, understanding the timing, duration, and effort allocated to reproduction is vital to successful management of any species. The pearl darter, Percina aurora, has been …
Comparing The Reproductive Fitness Of Fundulus Hybrids And Their Parental Species (Fundulus Olivaceus And Fundulus Notatus) Within Mississippi Freshwater Contact Zones, Sarah Stovall
Honors Theses
Hybridization of closely related taxonomic groups within the Animal Kingdom has led to complex species interactions that are not well understood. Pre-zygotic or post-zygotic barriers complicate hybridization as a means to diversify; however, diverging hybrids may speciate and expedite evolution of involved taxa. This study pursues understanding of these intricate interactions using topminnow Fundulus notatus, Fundulus olivaceus, and their hybrids from the Fundulus notatus species complex. Persisting hybrids within riverine contact zones were hypothesized to experience barriers of hybrid breakdown from lower fitness in comparison to the pure species. Specimens were collected within four contact zones: Spring River, …
Habitat Preference Of F. Notatus And F. Olivaceus From A Reversed Hybrid Zone, Elizabeth Hart Williams
Habitat Preference Of F. Notatus And F. Olivaceus From A Reversed Hybrid Zone, Elizabeth Hart Williams
Honors Theses
Understanding the mechanisms driving habitat preference throughout an organism’s life opens doors to the further understanding of the origins of diversity. Two species of minnow, Fundulus notatus and Fundulus olivaceus, are ideal for ecological research on habitat preference. Ordinarily, F. notatus and F. olivaceus display habitat preferences of downstream and upstream, respectively, with minimal coexistence at confluences. However, in some drainages, these preferences are flipped, like those in the Tombigbee River basin. Members of both species were collected from the Tombigbee River, tagged with species and sex specific colored elastomer marks, and placed in either a homogeneous control or …
Testing For Character Displacement Between Two Abundant Stream Fishes, Amber Nations
Testing For Character Displacement Between Two Abundant Stream Fishes, Amber Nations
Honors Theses
Character displacement is a pattern that can be used to explain differences between similar species in sympatric and allopatric situations. Gause’s Principle explains that a niche can only be occupied by one species at a time, so character displacement may be a way for similar species in the same habitat to shift resource use and compensate in order for the species to coexist. The Southeastern United States offers a unique opportunity to study this pattern because the diversity of freshwater fauna is quite high. However, the question of “How did this region become so diverse?” remains unanswered. One way for …
Patterns Of Genomic Introgression In Topminnow Hybrid Zones, Amanda F. Ray
Patterns Of Genomic Introgression In Topminnow Hybrid Zones, Amanda F. Ray
Honors Theses
Hybridization and introgression are two important evolutionary mechanisms that can increase genetic diversity. Interesting introgression patterns can form when parental species have genes that confer some adaptive benefit to the organism. The Fundulus notatus species complex contains species with various identifying characterisics. Fundulus notatus, the blackstripe topminnow, and Fundulus olivaceus, the blackspotted topminnow, are closely related and occupy many of the same rivers in their preferred niches. These two species often hybridize and form hybrid zones where their niches overlap. We studied two hybrid zones located in the Tombigbee River and Spring River. Within each hybrid zone, we …
Age-Related Tick Infestation Patterns In Springtime Migratory Passerines, Matthew Dunning
Age-Related Tick Infestation Patterns In Springtime Migratory Passerines, Matthew Dunning
Honors Theses
To test the hypothesis that younger migrants are more prone to arrive at stopover sites on the northern coast of the Gulf of Mexico with ticks than adult migrants, 2177 migratory passerines were screened for ticks at Gulf Coast sites in Texas and Louisiana. Fifty eight (2.7%) were infested with ticks with 28 (1.3%) being young birds and 30 (1.4%) being adult birds. The body condition of the birds was assessed to determine if tick infestation had negative consequences and if the severity of consequences varied between ages. I found no relationship of age with the prevalence of a tick …
Effect Of Reinforcement Selection On Mate Selection Rates Of Gambusia Affinis And Gambusia Holbrooki, Molly Stephens
Effect Of Reinforcement Selection On Mate Selection Rates Of Gambusia Affinis And Gambusia Holbrooki, Molly Stephens
Honors Theses
This study was conducted in order to investigate the effects that reinforcement selection has on non-hybridized and hybridized populations of two separate species of Gambusia (G. affinis and G. holbrooki). In order to examine if organisms from a population that had been previously exposed to hybridization would choose mates so as to not produce species hybrid offspring, 29 trials consisting of 9 different mate preference combinations and 87 individuals were recorded and analyzed. Once mate preference was determined for each female used in each trial, the effect that reproductive isolation had on reinforcement in hybrid zones was analyzed. The results …
Sibship Reconstruction For Inferring The Number Of Breeders Of Gulf Sturgeon In The Apalachicola River, Robbilyn Verges
Sibship Reconstruction For Inferring The Number Of Breeders Of Gulf Sturgeon In The Apalachicola River, Robbilyn Verges
Honors Theses
The Gulf sturgeon is an anadromous fish that inhabits the Gulf of Mexico and its neighboring river drainages. The species is currently listed as threatened due to habitat alterations and overfishing. In this study, we focused on the Apalachicola River in Florida, which has had several historic spawning locations of the sturgeon blocked by the Jim Woodruff Lock and Dam. Age-1 juvenile sturgeon from the year 2013 (n=31) and 2014 (n=131) were genotyped using fourteen microsatellite loci. Sibship reconstruction and parentage assignment was performed in order to determine the effective number of breeders (Nb) and the total number of spawning …
Genetic Estimates Of The Number Of Breeding Adults In Alligator Gar From The Choke Canyon Reservoir, Texas, E. Blayne Newsome
Genetic Estimates Of The Number Of Breeding Adults In Alligator Gar From The Choke Canyon Reservoir, Texas, E. Blayne Newsome
Honors Theses
Alligator gar were historically found across the coastal drainages of the Gulf of Mexico and up into the Mississippi River basin. However, their populations are experiencing decline in many portions of their range. Texas seems to have large populations of alligator gar, but state resource officers are seeking to better understand its biology so as to provide appropriate management recommendations to maintain the recreational fishery. In this study, I used genetic techniques to examine a cohort of 144 juvenile alligator gar collected in 2016 in the Choke Canyon Reservoir. By estimating the effective number of breeders and number of spawning …
Morphological, Genetic, And Environmental Characterization Of An Unusual Population Of Isoetes (Isoetaceae, Lycopodiophyta), Shannon L. Walker
Morphological, Genetic, And Environmental Characterization Of An Unusual Population Of Isoetes (Isoetaceae, Lycopodiophyta), Shannon L. Walker
Honors Theses
A large and unusual population of Isoetes (Isoetaceae, Lycopodiophyta) in the DeSoto National Forest, Wayne County, Mississippi, was studied to determine if the individuals there represent a new species or if they represent part of the variation of the one primary species of the longleaf pine belt of Mississippi, Isoetes louisianensis, which it most closely resembles. The unusual population and specimens of known Isoetes louisianensis were examined comparatively based on morphology, megaspore ornamentation, examination of habitat characteristics, and phylogenetic analysis of DNA sequence data from the nuclear internal transcribed spacer 1 and 2 (ITS) and the 5.8S ribosomal gene. No …
Salinity Tolerance Of Gambusia Affinis, Sarah Rubelowsky
Salinity Tolerance Of Gambusia Affinis, Sarah Rubelowsky
Honors Theses
Developmental plasticity refers to changes during development as a result of environmental contributions. Salinity is a varying environmental condition in freshwater and estuarine habitats that can mediate developmental plasticity in Gambusia affinis, which can increase their tolerances as an invasive species. For my study, estuarine and freshwater populations of Gambusia affinis were sampled in March of 2017 using dip nets. Both populations were then brought back to the laboratory where pregnant females were acclimated to three different salinities (0‰, 15‰, 25‰) until they gave birth. I predicted that the estuarine population of Gambusia affinis would have a greater salinity tolerance …
Effects Of Temperature Gradient, Substrate Composition, And Canopy Cover On The Spatial Distribution Of Topminnow Species: Fundulus Notatus And Fundulus Olivaceus, Austin M. King
Honors Theses
Hybrid zones are locations where two interbreeding species coexist and hybridize. The spatial distribution of ecologically similar species is of primary interest in understanding the formation and stability of hybrid zones. These hybrid zones are of significance as they allow for insight into how speciation occurs naturally within the environment. A variety of factors may play a role in determining the spatial distributions of species within hybrid zones. Examples of these factors include variations in temperature gradients, substrate composition, and changes in canopy cover. Fundulus olivaceus and Fundulus notatus are generally found within upstream and downstream habitats respectfully. These habitats …
Phylogenetic Relationships Of The Genera Of Achariaceae Based On Analyses Of Morphological And Dna Data, Corey L. Pagart
Phylogenetic Relationships Of The Genera Of Achariaceae Based On Analyses Of Morphological And Dna Data, Corey L. Pagart
Honors Theses
Achariaceae are a mostly tropical family of flowering plants consisting of about 29 genera and 150 species of trees and shrubs. Although they are closely related to passionflowers (Passifloraceae), violets (Violaceae), and willows and cottonwoods (Salicaceae), phylogenetic relationships of the genera remain unclear because the only studies have been focused on particular genera or had limited sampling. Few studies of the family in general have been conducted, except for some on species that produce chaulmoogra oil, a commonly used historical treatment for leprosy. For my study, I investigated the relationships of the genera within the family using morphological and molecular …
The Evolution Of Body Size In The Order Siluriformes, D Cooper Campbell
The Evolution Of Body Size In The Order Siluriformes, D Cooper Campbell
Honors Theses
The evolution of body size has long been a topic of interest to biologists due to the close link between size and various aspects of an organism’s biology. Adult body size is influenced by the underlying tradeoff in energy allocation between maintenance, somatic growth and reproduction. I studied the evolution of a large group of globally distributed (primarily freshwater with some marine forms) fishes to test some basic hypotheses about the evolution of adult body size. Catfish (Siluriformes) are an excellent group for this type of research as they represent approximately 11% of fishes and species range in size from …