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Ecology and Evolutionary Biology

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Full-Text Articles in Life Sciences

Individual And Population Responses To Hydrologic Variability In A Headwater Stream Salamander, Madaline Cochrane Jan 2023

Individual And Population Responses To Hydrologic Variability In A Headwater Stream Salamander, Madaline Cochrane

Graduate Student Theses, Dissertations, & Professional Papers

Understanding how organisms respond to environmental variability is a central goal in ecology – a goal made even more pressing by the herculean challenge global climate change presents to all organisms. Climate change is increasing the frequency and intensity of floods and droughts, which will likely have disproportionate effects on freshwater organisms. Many stream-associated species have multi-stage life histories. However, we lack an empirical understanding of life history and movement responses of these organisms to hydrologic disturbances, and how these responses may influence demographic rates. In my dissertation, I used a combination of growth, developmental, movement, and demographic data to …


Length-Weight Relationships Of The Bream Abramis Brama (Linnaeus, 1758) In Beni- Haroun Dam Of Mila City (North-East Of Algeria), Tolba Mounia, Hadjab Ramzi, Chikara Bouziani Mohamed, Berrouk Houda, Kaouachi Nouha Dec 2022

Length-Weight Relationships Of The Bream Abramis Brama (Linnaeus, 1758) In Beni- Haroun Dam Of Mila City (North-East Of Algeria), Tolba Mounia, Hadjab Ramzi, Chikara Bouziani Mohamed, Berrouk Houda, Kaouachi Nouha

Journal of Bioresource Management

The study of fish growth is a valuable tool in providing good understanding on the general biology and growth of fish populations, in addition to the comparison of the same fish species populations living in remote geographic areas. Thus, the present work was designed to study the age and growth of Abramis brama species newly introduced in Beni-Haroun dam (Mila department, Northeast Algeria). Here, the study was conducted on sampling of 141 individuals from July 2015 to October 2016. The age of fishes was determined according to scalimetric method, since the fish sex was determined by macroscopic method, showing that …


Fast And Furious: Energetic Tradeoffs And Scaling Of High-Speed Foraging In Rorqual Whales, William T. Gough, David E. Cade, Max F. Czapanskiy, Jean Potvin, Frank E. Fish, Shirel R. Kahane-Rapport, Matthew S. Savoca, K. C. Bierlich, David W. Johnston, Ari S. Friedlaender, Andy Szabo, Lars Bejder, Jeremy A. Goldbogen Sep 2022

Fast And Furious: Energetic Tradeoffs And Scaling Of High-Speed Foraging In Rorqual Whales, William T. Gough, David E. Cade, Max F. Czapanskiy, Jean Potvin, Frank E. Fish, Shirel R. Kahane-Rapport, Matthew S. Savoca, K. C. Bierlich, David W. Johnston, Ari S. Friedlaender, Andy Szabo, Lars Bejder, Jeremy A. Goldbogen

Biology Faculty Publications

Although gigantic body size and obligate filter feeding mechanisms have evolved in multiple vertebrate lineages (mammals and fishes), intermittent ram (lunge) filter feeding is unique to a specific family of baleen whales: rorquals. Lunge feeding is a high cost, high benefit feeding mechanism that requires the integration of unsteady locomotion (i.e., accelerations and maneuvers); the impact of scale on the biomechanics and energetics of this foraging mode continues to be the subject of intense study. The goal of our investigation was to use a combination of multi-sensor tags paired with UAS footage to determine the impact of morphometrics such as …


Benthic Community Dynamics And Stony Coral Demographics In Florida In Relation To Acute Disturbances And Chronic Pressures, Nicholas P. Jones Aug 2022

Benthic Community Dynamics And Stony Coral Demographics In Florida In Relation To Acute Disturbances And Chronic Pressures, Nicholas P. Jones

All HCAS Student Capstones, Theses, and Dissertations

The persistence of coral reef communities is threatened by a suite of pressures operating at varying spatial and temporal scales. In general, acute disturbances (short term stochastic events such as marine heatwaves or hurricanes) and chronic pressures, such as ocean warming, have caused the most significant changes to stony coral assemblages (order Scleractinia) and continue to impair recovery potential. Additionally, many coral reefs are subject to local chronic anthropogenic pressures resulting in poor water quality or sedimentation, which further impact stony corals and shape benthic community structure, particularly near urbanized coastlines. For the viability of communities on coral reefs, a …


Effects Of Snake Fungal Disease On The Survival And Growth Of The Queensnake (Regina Septemvittata), Andrew Jerome Ibach Jan 2022

Effects Of Snake Fungal Disease On The Survival And Growth Of The Queensnake (Regina Septemvittata), Andrew Jerome Ibach

Theses and Dissertations--Forestry and Natural Resources

Having only emerged as a threat to snakes in 2006, relatively little is known of snake fungal disease’s (SFD) impacts on demographic processes, particularly survival and growth. I used data from an extensive capture-mark-recapture study to examine survival and growth in central Kentucky Queensnake (Regina septemivittata) populations. I found that diseased snakes and healthy snakes possessed similar monthly survival estimates (SFD positive 0.9687, 95% CI 0.8444 to 0.9944; SFD negative 0.8735, 95% CI 0.7518 to 0.9402) and that disease state transition probability from SFD negative to SFD positive, and SFD positive to SFD negative were also similar (N-P …


Smallmouth Bass (Micropterus Dolomieu) Population Characteristics And An Evaluation Of Management Responses In Two West Virginia Watersheds, Jacob D. Harrell Jan 2022

Smallmouth Bass (Micropterus Dolomieu) Population Characteristics And An Evaluation Of Management Responses In Two West Virginia Watersheds, Jacob D. Harrell

Graduate Theses, Dissertations, and Problem Reports

Smallmouth Bass (Micropterus dolomieu) population characteristics were examined within the Tygart and Cheat River watersheds of north-central West Virginia. Growth, mortality and recruitment were examined for each individual population prior to modeling potential effects of various management schemes. Smallmouth Bass were sampled for total length and weight, aged using sagittal otoliths and sexed through observations of gonadal or ovarian development. Growth for each population was examined using von Bertalanffy growth models and assessed for variation among populations. Population demographic characteristics differed between and among populations, most noticeably between riverine and lacustrine habitat, whereby growth, mortality and recruitment were higher …


The Atlantic Surfclam Fishery And Offshore Wind Energy Development: 1. Model Development And Verification, Daphne M. Munroe, Eric N. Powell, John M. Klinck, Andrew M. Scheld, Sarah Borsetti, Jennifer Beckensteiner, Eileen E. Hofmann Jan 2022

The Atlantic Surfclam Fishery And Offshore Wind Energy Development: 1. Model Development And Verification, Daphne M. Munroe, Eric N. Powell, John M. Klinck, Andrew M. Scheld, Sarah Borsetti, Jennifer Beckensteiner, Eileen E. Hofmann

CCPO Publications

Competing pressures imposed by climate-related warming and offshore development have created a need for quantitative approaches that anticipate fisheries responses to these challenges. This study used a spatially explicit, ecological-economic agent-based model integrating dynamics associated with Atlantic surfclam stock biology, decision-making behavior of fishing vessel captains, and fishing fleet behavior to simulate stock biomass, and fishing vessel catch, effort and landings. Simulations were implemented using contemporary Atlantic surfclam stock distributions and characteristics of the surfclam fishing fleet. Simulated distribution of fishable surfclam biomass was determined by a spatially varying mortality rate, fishing by the fleet was controlled by captain decisions …


Trophic Ecology Of Juvenile Lean And Siscowet Lake Trout (Salvelinus Namaychush) From U.S. Waters Of Lake Superior, Will Otte Dec 2021

Trophic Ecology Of Juvenile Lean And Siscowet Lake Trout (Salvelinus Namaychush) From U.S. Waters Of Lake Superior, Will Otte

All NMU Master's Theses

In this study, I investigated the spatial overlap, diet similarity, and isotopic niches of juvenile Lean and Siscowet Lake Trout ecotypes across six ecoregions of Lake Superior. Spatially, Lean and Siscowet were observed in overlapping depth distributions. Leans were most abundant in shallow waters (60m). The greatest levels of cohabitation were observed in waters from 40-60m. Trophic position (as measured by δ 15N) was similar for both ecotypes at small sizes (mm), but Siscowet exhibited a higher trophic position than Lean Lake Trout at larger sizes (>400mm) and older ages (>5 years). Base of production (as measured by …


Smallmouth Bass Feeding Dynamics And Growth In Headwater Streams Of The Interior Highlands, Brandon C. Plunkett May 2021

Smallmouth Bass Feeding Dynamics And Growth In Headwater Streams Of The Interior Highlands, Brandon C. Plunkett

ATU Theses and Dissertations 2021 - Present

Smallmouth Bass have been extensively studied, but knowledge of the effects of temperature and hydrologic regime on populations in the Interior Highlands of Arkansas remains lacking. In 2018, I monitored diet characteristics of Smallmouth Bass, located in streams prone to dryness and representing a range of water temperatures, and presence of potential competitors. Diet characteristics of Smallmouth Bass, Green Sunfish, and Creek Chub were studied in the Boston Mountains ecoregion of Arkansas during the summer of 2018. In 2019, I expanded the scope of the project to search for relationships between Smallmouth Bass growth and hydrologic regime. My objectives were …


European Aspen With High Compared To Low Constitutive Tannin Defenses Grow Taller In Response To Anthropogenic Nitrogen Enrichment, Franziska Bandau, Benedicte Riber Albrectsen, Kathryn M. Robinson, Michael J. Gundale Feb 2021

European Aspen With High Compared To Low Constitutive Tannin Defenses Grow Taller In Response To Anthropogenic Nitrogen Enrichment, Franziska Bandau, Benedicte Riber Albrectsen, Kathryn M. Robinson, Michael J. Gundale

Aspen Bibliography

Boreal forests receive nitrogen-(N)-enrichment via atmospheric deposition and industrial fertilization. While it is known that N-enrichment can intensify interactions with natural antagonists, it remains poorly understood how genetic variability in plant defense chemistry can affect biotic interactions and height growth in N-enriched environments. We grew replicates of five low- and high-tannin Populus tremula genotypes, respectively, under three N-treatments (ambient, 15, and 150 kg N ha−1 yr−1). We assessed shoot blight occurrence (i.e. symptoms caused by Venturia fungi) during four growing seasons, and tree height growth during the same period. Damage by Venturia spp. increased with N-addition during all years, likely …


Kelp-Associated Microbes Facilitate Spatial Subsidy In A Detrital-Based Food Web In A Shoreline Ecosystem, Charu Lata Singh, Megan J. Huggett, Paul S. Lavery, Christin Säwström, Glenn A. Hyndes Jan 2021

Kelp-Associated Microbes Facilitate Spatial Subsidy In A Detrital-Based Food Web In A Shoreline Ecosystem, Charu Lata Singh, Megan J. Huggett, Paul S. Lavery, Christin Säwström, Glenn A. Hyndes

Research outputs 2014 to 2021

Microbes are ubiquitous but our knowledge of their effects on consumers is limited in benthic marine systems. Shorelines often form hotspots of microbial and detritivore activity due to the large amounts of detrital macrophytes that are exported from other coastal ecosystems, such as kelp forests, and accumulate in these systems. Shoreline ecosystems therefore provide a useful model system to examine microbial-detritivore interactions. We experimentally test whether bacteria in the biofilm of kelp provide a bottom-up influence on growth and reproductive output of detritivores in shorelines where detrital kelp accumulates, by manipulating the bacterial abundances on kelp (Ecklonia radiata). The growth …


Age, Growth, And Mortality Of Atlantic Tripletail In The North-Central Gulf Of Mexico, Amanda E. Jefferson, Matthew B. Jargowsky, Meagan N. Schrandt, Pearce T. Cooper, Sean P. Powers, John Dindo, J. Marcus Drymon Jan 2021

Age, Growth, And Mortality Of Atlantic Tripletail In The North-Central Gulf Of Mexico, Amanda E. Jefferson, Matthew B. Jargowsky, Meagan N. Schrandt, Pearce T. Cooper, Sean P. Powers, John Dindo, J. Marcus Drymon

University Faculty and Staff Publications

In the southeastern USA and the Gulf of Mexico (GOM), Atlantic Tripletail Lobotes surinamensis are increasingly targeted by recreational anglers, indicating that stock status should be assessed. A critical need for such assessments is age-specific data; however, previous studies have drawn conflicting conclusions regarding the most appropriate structure for aging. Moreover, growth parameters and mortality rates for GOM Atlantic Tripletail are unknown. Therefore, the goals of this study were to (1) evaluate sagittal otoliths and first dorsal spines as aging structures; (2) model combined and sex-specific growth; and (3) estimate mortality rates for GOM Atlantic Tripletail. From 2012 to 2019, …


An Invasive Species As A Threat To Native Biodiversity: Larval Competition Between Native Anurans And An Invasive Treefrog, Mckenzie Wasley Dec 2020

An Invasive Species As A Threat To Native Biodiversity: Larval Competition Between Native Anurans And An Invasive Treefrog, Mckenzie Wasley

Electronic Theses and Dissertations

Cuban Treefrogs (Osteopilus septentrionalis) are established in Florida and Louisiana and have invasive potential further westward, possibly impacting native anurans at multiple life stages. In anurans, competition at the larval stage can decrease adult fitness through slower development and smaller size at metamorphosis, ultimately decreasing recruitment rates. To examine the potential impacts of O. septentrionalis at the larval life-history stage, I quantified activity levels and growth of their tadpoles and those of two anurans native to eastern Texas: Green Treefrogs (Hyla cinerea) and Gulf Coast Toads (Incilius nebulifer). Tadpoles of the three species were …


Pismo Clams (Tivela Stultorum) In Califorina: Population Status, Habitat Associations, Reproduction, And Growth, Alexandria R. Marquardt May 2020

Pismo Clams (Tivela Stultorum) In Califorina: Population Status, Habitat Associations, Reproduction, And Growth, Alexandria R. Marquardt

Master's Theses

Marine shellfish play a vital role in intertidal ecosystems and coastal communities, but many of these fisheries are small-scale and lack the necessary monitoring to ensure long-term sustainability. Effective management often requires information on key demographic parameters, such as population status, reproduction and growth. Pismo clams (Tivela stultorum) are a culturally important and iconic species in California, which supported a thriving commercial and recreational fishery throughout much of the 1900’s. However, Pismo clam populations have declined statewide in recent decades and are attributed to human harvest and predation by California sea otters (Enhydra lutris); However, no …


Genetic Parameters Of Growth And Adaptive Traits In Aspen (Populus Tremuloides): Implications For Tree Breeding In A Warming World, Chen Ding, Andreas Hamann, Rong-Cai Yang, Jean S. Brouard Mar 2020

Genetic Parameters Of Growth And Adaptive Traits In Aspen (Populus Tremuloides): Implications For Tree Breeding In A Warming World, Chen Ding, Andreas Hamann, Rong-Cai Yang, Jean S. Brouard

Aspen Bibliography

Aspen (Populus tremuloides Michx) is a widespread commercial forest tree of high economic importance in western Canada and has been subject to tree improvement efforts over the past two decades. Such improvement programs rely on accurate estimates of the genetic gain in growth traits and correlated response in adaptive traits that are important for forest health. Here, we estimated genetic parameters in 10 progeny trials containing >30,000 trees with pedigree structures based on a partial factorial mating design that includes 60 half-sibs, 100 full-sib families and 1,400 clonally replicated genotypes. Estimated narrow-sense and broad-sense heritabilities were low for height …


Population Demographics Of Silver Carp Hypophthalmichthys Molitrix In Kentucky Lake, Allison M. Lebeda Jan 2020

Population Demographics Of Silver Carp Hypophthalmichthys Molitrix In Kentucky Lake, Allison M. Lebeda

Murray State Theses and Dissertations

Invasive species continue to threaten aquatic ecosystems in the United States. Silver Carp Hypophthalmichthys molitrix have successfully infiltrated much of the Mississippi River Basin, including Kentucky Lake – a large reservoir located on the Tennessee River in Western Kentucky. Although Silver Carp have been present in Kentucky Lake for at least a decade, until recently, very little was known about the population, how often successful reproduction is occurring, or the environmental conditions that facilitate strong year-classes. Hence, it is difficult for managers to predict the potential impact of Silver Carp on native species. Silver Carp were collected from Kentucky Lake …


The Effects Of Boring Sponge Infestation On Condition, Growth, And Sex Change In Crepidula Fornicata, Nicole L. Kleinas Jan 2020

The Effects Of Boring Sponge Infestation On Condition, Growth, And Sex Change In Crepidula Fornicata, Nicole L. Kleinas

Electronic Theses and Dissertations

The Atlantic slipper limpet, Crepidula fornicata, is a sequential hermaphrodite whose size at sex-change is plastic with respect to social and population cues. As an organism allocates energy between growth, reproduction and maintenance, an increased cost of one process may affect another. In this paper, I evaluate whether the presence of an epibiotic sponge (Cliona celata) affects the growth, condition and sex-change of C. fornicata individuals. Population surveys demonstrate a variable effect of Cliona presence on C. fornicata condition. The results of a twelve-week in situ experiment demonstrated a decrease in growth when C. celata was present. …


Pre-Juvenile Naked Goby (Gobiosoma Bosc) Age And Growth, Annamaria Deitz, Juliana Harding Dec 2019

Pre-Juvenile Naked Goby (Gobiosoma Bosc) Age And Growth, Annamaria Deitz, Juliana Harding

Honors Theses

Due to the abundance of larval naked gobies, Gobiosoma bosc, within the estuarine ichthyoplankton, it is important to understand their age and growth. Naked gobies are a largely distributed, both geographically and within an estuary, small, benthic fish species. There are 3 pairs of otoliths, calcium carbonate structures within the ear canal, that detect vibrations and record the age of the fish, both daily and annually. Using laboratory-reared gobies of a known age (Tremont et al. 2015), daily signatures on the sagittal otoliths were first validated to be daily, then a growth curve for the wild caught larvae was …


Incorporating Early Life History And Recruitment In Analysis Of Population Dynamics Of Wetland Fishes, John Vincent Gatto Oct 2019

Incorporating Early Life History And Recruitment In Analysis Of Population Dynamics Of Wetland Fishes, John Vincent Gatto

FIU Electronic Theses and Dissertations

Hydrological variation is believed to be the major abiotic factor influencing fish recruitment in floodplain ecosystems. However, past studies fail to address the impact of hydrology on the three major drivers of recruitment: age-specific growth and mortality, and dispersal. I examined long-term recruitment dynamics for six fish species inhabiting the Everglades by addressing the impact of hydrology on these important characteristics. I then linked these changes to annual fluctuations in population size.

Before interpreting time-series data on recruitment, I evaluated the impact of size-selective bias from sampling gear on our interpretation of hydrological drivers of recruitment. Analyses revealed that individuals …


Population Characteristics Of Co-Managed White Bass And Hybrid Striped Bass In Lake Mcconaughy, Nebraska, Benjamin J. Schall, Casey W. Schoenebeck, Keith D. Koupal Mar 2019

Population Characteristics Of Co-Managed White Bass And Hybrid Striped Bass In Lake Mcconaughy, Nebraska, Benjamin J. Schall, Casey W. Schoenebeck, Keith D. Koupal

Transactions of the Nebraska Academy of Sciences and Affiliated Societies

White Bass (Morone chrysops) and Hybrid Striped Bass (M. saxatillis × M. chrysops) populations often coexist in the same waterbody and are known to achieve different lengths, have differing reproductive success, and provide different opportunities for anglers. However, comparative population dynamics from systems where Moronids are managed with the same regulation is often lacking. This study aimed to assess the recruitment, mortality, and growth of these species from seasonal samples collected at Lake McConaughy in 2015 and fall 2016. White Bass demonstrated highly variable recruitment in Lake McConaughy despite stocking efforts (mean recruitment variability index = …


Growth And Survival Of Wild And Head-Started Blanding’S Turtles (Emydoidea Blandingii), Callie Klatt Golba Jan 2019

Growth And Survival Of Wild And Head-Started Blanding’S Turtles (Emydoidea Blandingii), Callie Klatt Golba

Graduate Research Theses & Dissertations

Blanding’s Turtles (IUCN Endangered) are long-lived reptiles with delayed sexual maturity. Anthropogenic landscape changes have increased threats to juvenile turtles, resulting in unnaturally low recruitment. Head-starting has become a popular conservation strategy that aims to increase juvenile recruitment by avoiding the increased predation of the vulnerable nest and hatchling age-class. However, there is still debate about whether or not it is an effective management tool. Assessments of head-starting are becoming more prevalent, but long-term studies are needed to critically evaluate the success of such interventions. In particular, information is needed on how head-starts fare compared to wild-born turtles. The Lake …


Causes And Possible Consequences Of Hybridisation In Angelfishes At Christmas Island, Federico Vitelli Jan 2019

Causes And Possible Consequences Of Hybridisation In Angelfishes At Christmas Island, Federico Vitelli

Theses: Doctorates and Masters

The angelfishes (family Pomacanthidae) have the greatest proportion (~30%) of hybridising species, compared to other families of reef fishes, with 26 species implicated in hybridisation. However, very little is known about hybridisation in angelfish, especially in terms of fitness of the hybrids and possible ecological consequences. Hybrids between three species (C. flavissima, C. eibli and C. vroliki) in the genus Centropyge have previously been reported from Christmas island, where these have been observed in heterospecific harems and interbreeding. This provides the unique opportunity to examine the breakdown in assortative mating in marine fishes. The broad aim of this …


The Effect Of Shelter Availability On Foraging In Atlantic Salmon (Salmo Salar), Christian A. Therrien Sep 2018

The Effect Of Shelter Availability On Foraging In Atlantic Salmon (Salmo Salar), Christian A. Therrien

Electronic Thesis and Dissertation Repository

Shelter is an environmental feature that provides protection from danger and its use is an important anti-predator behavior for juvenile Atlantic salmon (Salmo salar). However, how shelter availability influences the foraging of these fish in the wild is not well documented. I predicted that juvenile Atlantic salmon would alter their foraging behavior in a low shelter environment and that this effect would differ between individuals from two populations that are targeted for reintroduction into Lake Ontario. I measured the foraging activity of juvenile Atlantic salmon from the two populations while they were held in pens in a Lake …


Analysis Of Temperature And Salinity Effects On Growth And Mortality Of Oysters (Crassostrea Virginica) In Louisiana, Troy Sehlinger Aug 2018

Analysis Of Temperature And Salinity Effects On Growth And Mortality Of Oysters (Crassostrea Virginica) In Louisiana, Troy Sehlinger

University of New Orleans Theses and Dissertations

Salinity (S) and temperature (T) control every facet of the eastern oyster (Crassostrea virginica) life cycle, principally reproduction, development, growth, and mortality. Previous studies conducted in in the Breton Sound (BR) and Barataria (BA) estuaries have reported differences in growth and mortality rates between the basins. In the present study, environmental conditions were synchronized to compare growth and mortality rates between basins at similar combinations of T and S. Results indicate that when T and S are the same (synchronized), seasonal oyster growth and mortality rates differ between BR and BA. Seasonal analyses revealed that as salinities increased …


Sensitivity Of Quagga Mussels (Dreissena Rostriformis Bugensis) To Cyanobacteria At Multiple Life History Stages, Anna Boegehold Jan 2018

Sensitivity Of Quagga Mussels (Dreissena Rostriformis Bugensis) To Cyanobacteria At Multiple Life History Stages, Anna Boegehold

Wayne State University Dissertations

Quagga mussels (Dreissena rostriformis bugensis) originate from brackish waters of the Ponto-Caspian area and are nuisance invasive species in North American and European freshwaters. Their invasion has caused major economic and ecological damages in the Laurentian Great Lakes. Through selective filter feeding, quagga mussels have promoted the growth of cyanobacteria. Harmful cyanobacteria blooms have the potential to produce toxins, which can be toxic to humans and wildlife. Although quagga mussels can increase the prevalence of cyanobacteria blooms, it is unknown how they are physiologically affected by cyanobacteria and understanding these dynamics can be useful in the management of this invasive …


How Metamorphosis Is Different In Plethodontids: Larval Life History Perspectives On Life-Cycle Evolution, Christopher K. Beachy, Travis Ryan, Ronald M. Bonett Oct 2017

How Metamorphosis Is Different In Plethodontids: Larval Life History Perspectives On Life-Cycle Evolution, Christopher K. Beachy, Travis Ryan, Ronald M. Bonett

Scholarship and Professional Work - LAS

Plethodontid salamanders exhibit biphasic, larval form paedomorphic, and direct developing life cycles. This diversity of developmental strategies exceeds that of any other family of terrestrial vertebrate. Here we compare patterns of larval development among the three divergent lineages of biphasic plethodontids and other salamanders. We discuss how patterns of life-cycle evolution and larval ecology might have produced a wide array of larval life histories. Compared with many other salamanders, most larval plethodontids have relatively slow growth rates and sometimes exceptionally long larval periods (up to 60 mo). Recent phylogenetic analyses of life-cycle evolution indicate that ancestral plethodontids were likely direct …


Evidence Of Multidecadal Recruitment In The Ocean Quahog, Arctica Islandica In The Western Atlantic Ocean, Sara M. Pace Aug 2017

Evidence Of Multidecadal Recruitment In The Ocean Quahog, Arctica Islandica In The Western Atlantic Ocean, Sara M. Pace

Master's Theses

Ocean quahogs (Arctica islandica) are the longest-lived, non-colonial animals known today, with a maximum life span exceeding 500 years. Limited information is available regarding recruitment, making the sustainable management of this valuable fishery a challenge. The objective of this research was to describe the age structure and growth rates for four populations of ocean quahogs from the mid-Atlantic stock to evaluate long-term recruitment trends. Clams were sectioned for age estimation to develop population age frequencies. Initial colonization began approximately 175-250 years ago depending upon site. All sites experienced an increase in recruitment beginning in the late 1800’s to …


Beyond Age And Stage: Consequences Of Individual Variation In Demographic Traits, Erin Elizabeth Feichtinger Jul 2017

Beyond Age And Stage: Consequences Of Individual Variation In Demographic Traits, Erin Elizabeth Feichtinger

USF Tampa Graduate Theses and Dissertations

Within natural populations, individuals vary in their propensity to grow, survive and produce offspring. Additionally, fates of individuals are often correlated and non-independent as a result of shared genes, rearing environment or both. Variation in demographic traits can change population dynamics over time. The effects of variation in individual growth rate on population growth rate, net reproductive rate and generation time are examined, along with quantifying the sources of variation in survival of a long-lived cooperatively breeding bird, the Florida Scrub-Jay (Aphelocoma coerulescens). I built a 2 stage population model with two growth phenotypes, fast and slow, and …


Effects Of A Large-Scale Habitat Enhancement Project On Largemouth Bass Behavior, Feeding, And Growth In Grand Lake, Texas, Chance Kirkeeng Jan 2017

Effects Of A Large-Scale Habitat Enhancement Project On Largemouth Bass Behavior, Feeding, And Growth In Grand Lake, Texas, Chance Kirkeeng

Electronic Theses and Dissertations

The quality of habitat, or the environment suitable for an organism to survive and reproduce, is often described by the type of features present and the quantity and condition of such features. Habitats in many ecosystems are declining and the loss of important habitats likely affects the success of organisms reliant upon those features. Habitats in reservoir ecosystems are especially at risk because of aging processes that are degrading reservoir habitats at faster rates than habitats in other ecosystems. Habitat enhancement projects are one tool used to combat the effects of aging reservoirs but the benefits of these management actions …


Effects Of Wildfires On Rattlesnake (Crotalus Oreganus) Growth And Movement In Washington State, Joseph Chase Jan 2017

Effects Of Wildfires On Rattlesnake (Crotalus Oreganus) Growth And Movement In Washington State, Joseph Chase

All Master's Theses

Fire is a dominant force in the Pacific Northwest that shapes ecosystems and influences wildlife, yet little is known of its effects on local predators. Northern Pacific rattlesnakes (Crotalus oreganus) comprise an excellent model to investigate how fire may influence wildlife because they are important predators that contribute to controlling prey populations, but are also unable to readily escape from wildfires. We developed a novel technique to assess growth rates of rattlesnakes by using digital photography to analyze differences in widths of their rattle segments laid down over time. We compared growth rates of rattlesnakes in habitats that …