Ecology and Evolutionary Biology Commons^™

Eusocial Caste Specialization Under Abiotic And Biotic Stress In A Stingless Bee, Tetragonisca Angustula, Kristin M. Robinson

Dissertations

Eusocial insects rely on division of labor to achieve high colony efficiency and provide essential ecosystem services, but specialization may also constrain colony resilience when workers operate near their physiological or behavioral limits under abiotic and biotic stressors. How specialization mediates these responses remains poorly understood, particularly in stingless bees (Tribe: Meliponini). Using the agriculturally relevant stingless bee Tetragonisca angustula, which possesses a specialized soldier subcaste, I investigated how a high degree of worker specialization influences physiological tolerance and predator responses across worker subcastes.

In this dissertation, I quantified variation in thermal tolerance and desiccation resistance among worker subcastes …

One Assay To Rule Them All: Development Of A Global Environmental Dna Tool To Support Range-Wide Surveys Of An Imperiled Sawfish And Its Application In The Eastern Tropical Pacific, Juan C. Cubillos-M, Annmarie Fearing, Demian D. Chapman, Peter M. Kyne, P. Joana Dias, Cindy Gonzalez, Ryan N. Lehman, Yaliana Chichaco, Bryan L. Huerta-Beltrán, Kayla L. Mcculloch, Sarah M. Toepfer, John K. Carlson, Nicole M. Phillips

Faculty Publications

Environmental DNA (eDNA) has emerged as a powerful tool to support the conservation of threatened species. The sawfishes are one of the most imperiled vertebrate groups, with all five species classified as Critically Endangered on the IUCN Red List of Threatened Species. Owing to their toothy rostra, sawfishes are easily entangled in a wide range of fishing gear, with mortalities in fisheries and loss of habitat driving global declines. The Largetooth Sawfish, Pristis pristis, historically had a circumtropical range, but has experienced severe declines in geographic range and abundance. Viable populations are thought to be confined to northern Australia, but …

Developing A Range Prediction For The Imperiled Florida Harvester Ant (Pogonomyrmex Badius) Using Species Distribution Modeling, Noah Williamson

Honors Theses

The Florida Harvester Ant (Pogonomyrmex badius) was once widespread and commonplace throughout the sandhills of the Southeastern United States, providing key ecosystem services, such as seed dispersal and soil aeration. Over recent decades, however, Florida Harvester Ant populations have declined in some areas. Current literature postulates that Red Imported Fire Ants (RIFA), and the insecticides used to manage them, as well as further human encroachment onto their habitat, all likely contributed to Florida Harvester Ant population declines. Thus, to better protect these organisms, pursue data-driven conservation efforts, and guide management practices, more information about their nest site selection, as well …

Variable Hybridization Rates Between F2 Fundulus Notatus Females, Jordan Tanaka

Honors Theses

Hybridization between two related species has been widely observed and offers a lens into complex evolutionary processes. Endogenous and exogenous factors affect hybrid fitness and diversification, and pre-zygotic and post-zygotic barriers affect species’ ability to hybridize. Female mate choice is a pre-zygotic isolation mechanism which is known to be more significant than male mate choice in many species, a trend which is linked to females often investing more energy into offspring. Detailing the ways in which these mechanisms operate is integral to understanding hybridization on a larger scale. The species examined here, Fundulus notatus and Fundulus olivaceous, are closely …

Evaluating The Environmental Parameters Impacting Spawning Movement Of Gulf Sturgeon (Acipenser Desotoi) In The Bouie River System., Olivia St. Germain

Honors Theses

The anadromous Gulf Sturgeon (Acipenser desotoi) is federally listed as “threatened” and is natal to seven rivers from Louisiana to Florida. Only one spawning reach for Gulf Sturgeon natal to the Pascagoula River has been verified via the collection of eggs and larvae; a reach of the lower Bouie River. This reach is anthropogenically modified by four gravel mining formations, hereafter referred to as pits. The greater depths associated with this area have prompted previous researchers to suggest that Gulf Sturgeon may over-summer in pit formations instead of migrating to downstream holding areas in the Pascagoula River after spawning. The …

Evaluating Donor Site Recovery Following Halodule Wrightii Harvest For Restoration In Northwest Florida, Katie M. Konchar, Becca A. Hatchell, Colin P. Shea, Bradley T. Furman, Kent Smith

Gulf and Caribbean Research

Bare‑root harvesting of Halodule wrightii is widely used to supply donor material for seagrass restoration, yet the capacity of donor meadows to recover in near‑temperate systems remains poorly documented. We evaluated donor‑site recovery following bare‑root harvesting in St. Andrew Bay, northwest Florida—an estuary at the northern extent of Tropical Atlantic Bioregion 2 where H. wrightii exhibits strong seasonal senescence and a shortened growing season. Thirty harvest impact sites were monitored for 388 days to quantify changes in shoot density, percent frequency, and sediment elevation relative to nearby reference conditions. Shoot density and percent frequency at harvested sites converged with reference …

Vegetation Species And Bed Position May Drive Epifaunal But Not Nekton Habitat Use In Estuarine Submerged Vegetation In The Mobile-Tensaw River Delta, Alabama, Steven Vroljik, Kathryn O'Shaughnessy, Ashley Mcdonald, Zoey Hendrickson, Bethany Kiley, Anna Reimer, Sierra Robertson, Samantha Smith, Edward Sullivan, Charles Martin

Gulf and Caribbean Research

Submerged aquatic vegetation (SAV) supports nekton and epifaunal macroinvertebrates, sustaining food webs and ecosystem services in estuaries. Invasive SAV can alter these dynamics by displacing native vegetation and restructuring communities. In Alabama’s Mobile-Tensaw Delta (MTD), Eurasian milfoil (Myriophyllum spicatum) is rapidly expanding and outcompeting native wild celery (Vallisneria americana). This study compared nekton and epifaunal assemblages between M. spicatum and V. americana, focusing on edge versus interior positions. Nekton surveys identified 22 taxa (M. spicatum, n = 13; V. americana, n = 18), but assemblages did not differ significantly between vegetation types …

Oyster Drill (Stramonita Haemastoma Complex) Habitat Preferences In A Shallow Coastal Estuary, Coen Mcgarrah, Cynthia Lupton, Eric Sparks, Jennifer L. Debose

Gulf and Caribbean Research

Southern oyster drill snails (Stramonita haemastoma complex) are nuisance organisms within the Gulf of Mexico. This is due to their damaging impact on recovering and farmed oyster (Crassostrea virginica) populations, which are one of the drills’ main food sources. Oyster reef recovery and increased aquaculture production are priorities for Mississippi and the wider northern Gulf coast. The Grand Bay National Estuarine Research Reserve (NERR) hosts multiple oyster reef restoration sites within its boundaries, yet no comprehensive survey of oyster drill abundance has been conducted in this area to date. Additionally, knowledge of oyster drill preferences for sediment …

Non-Native Seagrass, Halophila Stipulacea, Reaches Northern Caribbean, Elizabeth R. Whitman, Elizabeth W. Stoner, Stephanie K. Archer

Gulf and Caribbean Research

Halophila stipulacea, a seagrass native to the western Indian Ocean, has become an established invader throughout the western Atlantic, where it often outcompetes native seagrass species across diverse environmental conditions. Here, we report its presence in the northern Bahamas, ca. 2300 km northwest of the first Caribbean record in Grenada and 304 km northeast of the recent observation in Florida, USA. This range expansion represents the northernmost Caribbean record to date and highlights the species’ capacity for long-distance dispersal and continued spread within the region. Our observation underscores the need for coordinated monitoring efforts to track the trajectory of …

Manatee Dock Sign Distribution And Its Influence On Publicly-Sourced Sighting Reports In Alabama, Daniela Payán Arias, Sophia C. Corde, Ruth H. Carmichael

Gulf and Caribbean Research

No abstract provided.

Applying Transcriptomics For Technology Development And Conservation In North American Marine Organisms, Cory Von Eiff

Dissertations

RNA biology is a rapidly expanding field, with many avenues of discovery among marine organisms. In this study, we analyze both mollusks and sawfish. First, we perform an evaluation of sRNA biogenesis pathways throughout Mollusca, with emphasis on the easter oyster, Crassostrea virginica. Understanding these molecules prescribes RNAi-based gene silencing approaches, benefiting genetic investigation and biotechnology. Similar to other animal groups, mollusks have conserved microRNAs (miRNAs), with some shared with ecdysozoans and deuterostomes; however, there is no evidence of an endogenous small interfering RNA (siRNA) pathway. These results suggest that long double-stranded RNA (dsRNA)-based RNAi is not appropriate for gene …

Exploring Fisheries Species Distribution Shifts In Response To Freshwater Inflow Through The Bonnet Carré Spillway Using Species Distribution Models, David T. May

Master's Theses

The Bonnet Carre Spillway (BCS) is a flood control structure on the Mississippi River (MR) ~52 km upstream of New Orleans. The BCS protects downstream communities from MR flooding by diverting floodwaters into Lake Pontchartrain when the MR exceeds 5.18m flood stage. Diverted waters flow east into the Mississippi Sound (MSS), introducing turbid, nutrient rich freshwater to the estuary before draining into the Gulf of Mexico. BCS openings have become much more frequent in the last decade, though little work has been done to explore the impact of the BCS on nektonic fisheries species. Here, a series of seasonal Maximum …

Determining The Influence Of A Low-Head Dam On Macroinvertebrate Communities In The Bouie River, Natalie Santiago

Honors Theses

The Bouie River is a tributary of the Leaf River and belongs to the Pascagoula River watershed, the latter of which has no flow impediments in the form of sills or dams. The Bouie River has been heavily altered in the lower 10 river kilometers (rkm) from aggregate mining (creating a series of deep gravel pits) and the presence of an earthen and concrete low-head dam (sill) located 6 rkm from the mouth of the river. However, despite these alterations, the immediate stretch of river below the low-head dam is a known spawning habitat for diadromous fish species, including the …

Sibship Analysis Of Fall And Spring Spawn Gulf Sturgeon Eggs In The Choctawhatchee River, Florida, Lyric Mccullouch

Honors Theses

The Gulf sturgeon (Acipenser oxyrinchus desotoi) is an anadromous species that inhabits rivers along the northern Gulf of Mexico. Facing challenges from overfishing and habitat alteration, the Gulf sturgeon is listed as threatened under the Endangered Species Act. This study investigated the genetic distinctiveness of fall and spring spawning groups of Gulf sturgeon in the Choctawhatchee River, a critical habitat for the species. In this study, I used microsatellite loci to analyze Gulf sturgeon eggs previously collected in the fall and spring of 2019 and 2020. The goals of this study were to verify the genetic identity of …

Population Estimates, Demography, And Habitat Assessment Of The Pearl River Map Turtle (Graptemys Pearlensis) In The Pearl River Drainage Of Mississippi, Noah Devros

Master's Theses

The Pearl River map turtle (Graptemys pearlensis) is a highly riverine Emydid endemic to the Pearl River drainage of central and southern Mississippi and southern Louisiana. First described in 2010, G. pearlensis was listed as federally Threatened in 2024. . Due to its relative novelty as a species, no rigorous site-specific population estimates of G. pearlensis in Mississippi have been conducted. The primary goal of this study was to implement a replicable method of assessing the population of G. pearlensis throughout the Pearl River drainage system of Mississippi. A secondary goal was to describe habitat associated with G. …

Macroinvertebrate Community Dynamics In A Recovering, Hypersaline Estuary, Catherine M. Eckert, Claudia A. Tamez, Erin E. Easton, David W. Hicks

Gulf and Caribbean Research

The Bahia Grande is a 6,500—acre tidal basin located at the southernmost tip of Texas. Tidal flow into this coastal estuary was cut off in the 1930s, causing the basin to dry up for ~70 y. A pilot channel connecting the Bahia Grande to tidal waters was constructed in 2005, allowing flooding of the basin to occur. Throughout the period reported herein (2005–2019), the system remained characterized by persistent spatial and temporal episodes of extreme hypersalinity (>70)—a critical factor influencing estuarine community composition and driving key ecological processes. With additional rehabilitation actions forthcoming, characterization of the estuary is essential …

Early Season Tropical Cyclones Affect Birds Breeding On A Barrier Island, Theodore J. Zenzal Jr., Amanda N. Anderson, Brock Geary, Jessica Schulz, Robert C. Dobbs, Wylie C. Barrow Jr., James H. Waddle

Gulf and Caribbean Research

Animal populations often experience acute natural disturbances, most of which are connected to short—term weather events. Occurrences of early—season tropical cyclones during the peak of the avian breeding season are likely to increase with climate change, which can substantially impact populations of coastal breeding birds at multiple scales. To understand the acute impacts of severe tropical cyclones, we investigated how abundances of breeding birds changed before and after 4 early season named tropical cyclones on a barrier island in the Gulf of Mexico. We detected a change in pre— versus post—storm numbers of breeding birds after 2 out of 4 …

Presence Of Potential Nursery Habitat For The Lemon Shark In Mississippi Coastal Waters, Lindsay K. Bomgardner, P. O. Grammer, Angie Hoover, Anna Millender, Jeremy Higgs, Jill M. Hendon, Michael J. Andres

Gulf and Caribbean Research

No abstract provided.

Ina Scuba: Mobilization Of French West Indies Scuba Diving Clubs To Rapidly Improve Knowledge On Threatened Marine Species. Case Of The White-Spotted Eagle Ray (Aetobatus Narinari)., Océane Beaufort, Rocio Prieto González

Gulf and Caribbean Research

The White—Spotted Eagle Ray (Aetobatus narinari), listed as Endangered on the IUCN Red List since 2021, is experiencing alarming population declines, underscoring the urgent need for targeted conservation efforts. This species, which plays a vital ecological role in marine food webs, has biological and ecological characteristics that make it particularly vulnerable to habitat degradation and anthropogenic pressures, particularly fishing, tourism, and maritime traffic. In the French West Indies (FWI), the paucity of data on the White—Spotted Eagle Ray remains a major obstacle to the development of effective, island—specific conservation strategies. To address this gap, the INA Scuba participatory …

Oyster Horizons: Spatial Prioritization For Oyster Restoration At Alabama Living Shorelines, Trinity Henry-Jack, Aaron Bland, Christa Russell, Ronald Baker

Gulf and Caribbean Research

No abstract provided.

Temporal And Spatial Changes In Phytoplankton Communities In A Shallow Coastal Estuary, Justin Osborne, Jeneil Patel, Jennifer L. Debose

Gulf and Caribbean Research

No abstract provided.

Investigating Nekton Response To Changing Salinities In The Mississippi Sound: An Experimental And Statistical Approach, Adam Murray

Master's Theses

The Mississippi Sound provides nursery habitats for many coastal species and is recognized for its commercial fisheries. Previous freshening events linked to the Bonnet Carré Spillway, a Mississippi River flood diversion structure, proved catastrophic for oyster populations in the Mississippi Sound, but effects on mobile fish and shellfish species are not well-defined. The planned Mid-Breton Sediment Diversion (MBSD), an initiative to combat wetland loss, is also forecasted to lower salinities in the region, increasing the need to better understand responses of commercially and ecologically important species to freshening events. The objective of this study was to characterize effects of salinity …

Geomorphic Assessment And Flow Modeling Of Pearl Darter (Percina Aurora) Habitat In The Pascagoula River Watershed, Malia Davidson

Master's Theses

Freshwater ecosystems are complex ecosystems driven by hydrologic, geomorphic, and biological processes. Considering both abiotic and biotic factors is important to understanding resident species habitat. Geomorphology is a known, but often neglected factor in habitat assessment for freshwater fishes. A crucial feature commonly seen in alluvial stream systems are sandbars, which are dynamic and variable sediment structures that are known to have many associated species. One such species is the Pearl Darter, Percina aurora, a federally threatened species that only resides in the Pascagoula River watershed. Despite its status, habitat preference remains unclear. To fill this knowledge gap, I …

Impact Of Thermal-Hydric Stress Of Physiological Performance And Mating Behavior Of Fiddler Crabs, Talene G. Yeghissian

Dissertations

Fiddler crabs live on the edge of their thermal tolerance limits, balancing the need to thermoregulate with the need to mate. Previous research suggests that increased temperature reduces fiddler crab surface activity time, thus decreasing mating opportunities, throughout the range species with greatest impacts to low latitude populations. The less studied missed mating opportunities associated with behavioral compensation for thermal stress are crucial to understanding species vulnerability to climate change. In this dissertation, I describe a combination of experimental and observational approaches in the field and in the laboratory to investigate the physiological and behavioral responses of fiddler crabs to …

Identifying New Potential Breeding Pond Sites For The Dusky Gopher Frog In Southern Mississippi, Shelbie Kellum

Master's Theses

The main objective of this thesis was to identify potential new pond sites across southern Mississippi for the critically endangered dusky gopher frog (DGF). Ephemeral ponds are the preferred breeding habitat for the species, but they are quite rare in the region due to the diminishment of the longleaf pine ecosystem. This research addresses gaps in the current literature by providing a broad overview of dusky gopher frog breeding habitat identification. LiDAR derived datasets as well as tools within ArcGIS Pro were utilized in order to perform spatial analysis on sites of interest in south Mississippi. By using this methodology …

Assessing The Impacts Of Grazing By Piney Woods Cattle And Controlled Burning On The Herbaceous Layer In An East Gulf Coastal Plain Longleaf Pine Woodland, William Mcfarland

Master's Theses

Fire and grazing are two disturbances which influence vegetation composition and diversity in many ecosystems. In the southeastern United States, longleaf pine plant communities are adapted to frequent fires and are likely to have been grazed by bison in the past. Though bison have been extirpated from this region, Pineywoods Cattle, which were introduced by the Spanish in the 16^th Century, have been fulfilling a similar role in many of these communities. This study examines the effects that combined grazing and controlled burning have on plant diversity, biomass, and community similarity in a longleaf pine savanna in the East …

Mate Choice Between Two Species Of Topminnows From Dissimilar Hybrid Zones, Chloe Davis

Honors Theses

Understanding the origins of reproductive isolation between closely related species is foundational to evolutionary and ecological research. Recent reviews have documented contemporary hybridization between a large portion of species. A greater knowledge of reproductive isolation and its components are vital to expanding conservation efforts for threats such as those to species persistence and community processes. However, there is a lack of clear understanding of how isolating mechanisms evolve throughout many systems where hybridization is prominent. Individuals within the Fundulus notatus species complex (F. notatus, F. olivaceus, and F. euryzonus) readily hybridize at many contact zones replicated throughout their …

Short-Term Temporal Trends Of A Coral Reef In Samana (Dominican Republic): The Value Of A Permanent Monitoring Program To Identify Drivers Of Rapid Change, Aldo Croquer, Someira Zambrano, D. Yasmín Evangelista-Perez, Samuel King, Sergio Guendulain-Garcia, Maria F Villalpando, Rita Sellares-Blasco

Gulf and Caribbean Research

Permanent monitoring programs are valuable to identify drivers of ecosystem trends. For example, in 2021, we reported the first record of Stony Coral Tissue Loss Disease (sctld) along the northeastern coast of the Dominican Republic, affecting major reef—building coral species with a prevalence above 30%. However, a few sites such as Carenero remained unaffected by sctld for almost 2 years. The average coral cover in this site was about 18—25% (mean 18.3% ± sd 1.5), and disease prevalence did not exceed 7% in the coral community. During the first quarter of 2022, a few colonies (

Nekton Community Responses To Living Shoreline Restorations In Alabama, Shelby Kuck, Christopher Grant, Matheus De Barros, Alexandra Rodriguez, Ronald Baker

Gulf and Caribbean Research

No abstract provided.

An Aggregation Of The Pandalid Shrimp, Heterocarpus Ensifer, On Deep Reef Habitats Of The West Florida Slope, Eastern Gulf Of Mexico, Steve W. Ross

Gulf and Caribbean Research

Heterocarpus ensifer A. Milne—Edwards (1881) (Crustacea: Pandalidae), armed nylon shrimp, is widely distributed in the western and eastern North Atlantic Ocean. In the western Atlantic this shrimp occurs from off North Carolina to Brazil and in the Gulf of Mexico (GOM), western Bahamas, and Caribbean Sea at depths of 170—885 m. Despite its widespread occurrence, ecology or biology information for this species are sparse, and in situ observations of abundance, behavior and habitat preferences are particularly lacking. During extensive submersible and ROV observations on and near deep—reefs in the north—central and eastern GOM, a remarkably large aggregation of H. ensifer …