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Theses/Dissertations

Amphibian

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Full-Text Articles in Ecology and Evolutionary Biology

The Nature And Extent Of Algal Symbiosis In Three North American Ranids, Zachary T. Vegso Jan 2024

The Nature And Extent Of Algal Symbiosis In Three North American Ranids, Zachary T. Vegso

Cal Poly Humboldt theses and projects

The symbiotic relationship between the chlamydomonad green alga Oophila amblystomatis and embryos of certain amphibian species is often presumed to be mutualistic. However, the existence of a mutualism has only been experimentally tested and established in two closely related ambystomatid salamanders. These experiments showed a positive correlation between intracapsular algal density and embryonic growth, survival, hatching synchrony, and hatchling body size. Oophila has been documented within egg capsules of a growing number of amphibian species, including several frogs in the family Ranidae. However, the nature and extent of this relationship remains unclear. Ranid eggs are better oxygenated than ambystomatid eggs, …

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Impacts Of Environmental Stressors On Native South Dakota Amphibian Physiology And Survival, Danielle Jean Galvin Dec 2023

Impacts Of Environmental Stressors On Native South Dakota Amphibian Physiology And Survival, Danielle Jean Galvin

Dissertations and Theses

Amphibian populations around the world are declining, with some of the most likely drivers behind these declines including emerging infectious diseases and environmental contaminants. To address major gaps in the current literature, I sought to evaluate the effect of two major environmental stressors on various aspects of amphibian physiology: emerging infectious diseases and environmental contaminants. Emerging infectious diseases of amphibians include fungal, viral, and parasitic pathogens which have expanded in host range, either geographically or in competent host species. Environmental contaminants include chemicals which may be naturally occurring in the environment, or which may be introduced to the environment, often …

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An Ecological Survey Of East Texas Salamanders Across The Camp Tyler Outdoor Field School In Smith County, Texas, Justin C. Hunt Jul 2023

An Ecological Survey Of East Texas Salamanders Across The Camp Tyler Outdoor Field School In Smith County, Texas, Justin C. Hunt

Biology Theses

Amphibians are a unique class of organisms with a very long and storied evolutionary history of survival. Many modern amphibian clades occupy several vital ecological roles within their native freshwater environments. One of these roles, typically includes functioning as an ecological indicator species, whereby the presence of stable and diverse populations of many amphibian species, including salamanders, within a freshwater ecosystem have long been considered ecological indicators of good habitat quality and stable ecosystem health. Similarly, salamanders also function as important members of their local food webs and act as valuable mediators of complex trophic hierarchies to facilitate nutrient cycling …

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Pond-Breeding Amphibian Responses To Wetland Creation And Reforestation On A Legacy Surface Mine In The Monongahela National Forest, Lauren Breanna Sherman Jan 2023

Pond-Breeding Amphibian Responses To Wetland Creation And Reforestation On A Legacy Surface Mine In The Monongahela National Forest, Lauren Breanna Sherman

Theses and Dissertations--Forestry and Natural Resources

Surface mine reclamation has been an evolving practice since the Surface Mining Control and Reclamation Act was passed in 1977, holding mining companies accountable for returning ecological function to areas directly impacted by mining activities. One recent method of reclamation, the Forestry Reclamation Approach (FRA), aims to enhance reforestation and ecosystem function through the creation of wetlands, as opposed to traditional methods that often revert land to grasslands. However, wildlife response to FRA has rarely been investigated. The goal of this project was to analyze the effects of the four treatment types, FRA in two chronosequences, natural regeneration, and unmined …

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Joint Management Of Upland & Aquatic Habitat For The California Red-Legged Frog & California Tiger Salamander, Kyle E. Verblaauw Dec 2021

Joint Management Of Upland & Aquatic Habitat For The California Red-Legged Frog & California Tiger Salamander, Kyle E. Verblaauw

Master's Projects and Capstones

As federally and state protected amphibians, the California tiger salamander (Ambystoma californiense) and the California red-legged frog (Rana draytonii) are recipients of ample management focus. Both species face a variety of threats, including habitat loss and alteration, introduction of non-native species, spread of disease, and effects of climate change. While management plans for the California tiger salamander and California red-legged frog exist, they frequently do not consider both species in tandem and often contain multiple shortcomings. This document aims to address the shortfalls of current management by providing practical recommendations for jointly managing the upland and …

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Detection Of Neonicotinoids In Northern Leopard Frog (Rana Pipiens) Brains, Peyton G. Keller May 2021

Detection Of Neonicotinoids In Northern Leopard Frog (Rana Pipiens) Brains, Peyton G. Keller

Honors Thesis

Neonicotinoids are widespread and commonly used to fight agricultural pests. Unfortunately, these neurotoxic insecticides commonly reach nearby wetlands due to tile drainage systems and agricultural runoff. Non-target organisms, such as amphibians, use wetlands as habitat and are likely exposed to elevated neonicotinoid levels. We collected Northern leopard frogs and water samples from control and tile wetlands to compare imidacloprid brain concentrations and subsequent changes in brain morphology. Additionally, a lab-based experiment was conducted to further analyze the ability of imidacloprid and its metabolite, imidacloprid-olefin, to cross the blood-brain barrier. Tile wetlands had higher aquatic imidacloprid concentrations. Subsequently, amphibians collected from …

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Effects Of Infection Of The Protist Parasite, Dermomycoides Sp., In Dusky Gopher Frog Tadpoles, Jaime Smith Dec 2020

Effects Of Infection Of The Protist Parasite, Dermomycoides Sp., In Dusky Gopher Frog Tadpoles, Jaime Smith

Master's Theses

Infections of the protist parasite, Dermomycoides sp. are thought to have caused several years of low recruitment in the dusky gopher frog (Rana sevosa) populations. I evaluated the effects of density of the infective zoospores, host developmental stage, and tadpoles' ability to acquire resistance to Dermomycoides sp. on dusky gopher frog tadpoles. Tadpoles were exposed to zoospore densities of 0, 250, 500, and 750 zoospores/µL at Gosner stage 25, and we found no significant differences among treatments in tadpole mortality. In evaluating susceptibility by development stage, I exposed R. sevosa to 50 zoospores/µL as eggs, embryos, hatchlings, and …

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Evaluation Of Created Wetlands As Amphibian Habitat On A Reforested Surface Mine, Michaela M. Lambert Jan 2020

Evaluation Of Created Wetlands As Amphibian Habitat On A Reforested Surface Mine, Michaela M. Lambert

Theses and Dissertations--Forestry and Natural Resources

Reclaimed mines often lack pre-mining habitat due to soil compaction and lack of natural features. If soils are de-compacted and natural features restored, new habitats can be created, such as wetlands for amphibians. It is important to understand which factors affect amphibian use of wetlands to estimate the efficacy of created wetlands as habitat. I sampled 40 wetlands among 4 ages (2, 4, 6, and 8 years) on a reforested surface mine to: 1) characterize differences in wetland habitat across age classes, 2) estimate amphibian occupancy, 3) investigate estimated abundance of 4 amphibian species (Lithobates sylvaticus, L. clamitans, Notophthalmus …

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Toadal Isolation: Genetic Connectivity Of The Western Toad (Anaxyrus Boreas) Along I-90 In The Snoqualmie Pass Area Of Washington State, Anneliese Myers Jan 2020

Toadal Isolation: Genetic Connectivity Of The Western Toad (Anaxyrus Boreas) Along I-90 In The Snoqualmie Pass Area Of Washington State, Anneliese Myers

All Master's Theses

Single-nucleotide polymorphisms (SNPs) were used to assess the genetic connectivity of western toad (Anaxyrus boreas) breeding populations along Interstate-90 near Snoqualmie Pass, WA. Sites north and south of the freeway were sampled during the breeding season of 2019. SNP loci were subsequently generated using the proprietary DArTseqTM (Canberra, ACT, Australia) method. A total of 15,468 SNPs were used to calculate pairwise FST values and three distinct breeding populations were identified, two north and one south of I-90. All pairwise FST values between these sites were low (0.02) but significantly different from 0. The lowest pairwise …

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Effects Of Multiple Stressors: Hydroperiod, Introduced Bullfrogs, And Food Limitation On Northern Red-Legged Frogs (Rana Aurora), Lindsey L. Gordon Jan 2020

Effects Of Multiple Stressors: Hydroperiod, Introduced Bullfrogs, And Food Limitation On Northern Red-Legged Frogs (Rana Aurora), Lindsey L. Gordon

Cal Poly Humboldt theses and projects

As human activities reach every corner of the globe, climate change, invasive species, habitat destruction, and other stressors causing species’ declines no longer act alone. Climate change has the potential to exacerbate (or mitigate) other stressors (e.g. invasive species or pathogens) affecting amphibian populations. I assessed the combined effects of increased pond drying rates (potential impact of climate change), invasive bullfrogs (Lithobates catesbeianus) presence, and food availability on northern red-legged frog (Rana aurora) survival and body size after metamorphosis by rearing tadpoles under incrementally shortened hydroperiods with and without the presence of invasive bullfrog tadpoles in …

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Visual Opsin Diversity In Anurans, Leah Perez Aug 2019

Visual Opsin Diversity In Anurans, Leah Perez

Electronic Theses and Dissertations

Among major vertebrate groups, anurans are understudied with regards to their visual systems and how they function. This study sampled North American anurans representing diverse evolutionary and life histories and which likely possess visual systems adapted to meet different ecological needs. Using standard molecular techniques, sequences were obtained for four opsins—the protein component of visual pigments—expressed in anuran retinas. Amino acid sequences of the genes RH1, LWS, SWS1, and SWS2 were compared across taxa to identify variable sites, as such variation can shift the spectral sensitivity of visual pigments and thus alter dim-light and color vision. Some of the amino …

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Understanding The Impacts Of Current And Future Environmental Variation On Central African Amphibian Biodiversity, Courtney A. Miller Dec 2018

Understanding The Impacts Of Current And Future Environmental Variation On Central African Amphibian Biodiversity, Courtney A. Miller

University of New Orleans Theses and Dissertations

Global climate change is projected to impact multiple levels of biodiversity by imposing strong selection pressures on existing populations, triggering shifts in species distributions, and reorganizing entire communities. The Lower Guineo-Congolian region in central Africa, a reservoir for amphibian diversity, is predicted to be severely affected by future climate change through rising temperatures and greater variability in rainfall. Geospatial modelling can be used to assess how environmental variation shapes patterns of biological variation – from the genomic to the community level – and use these associations to predict patterns of biological change across space and time. The overall goal of …

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Eco-Evolutionary Implications Of Environmental Change Across Heterogeneous Landscapes, Jared J. Homola Aug 2018

Eco-Evolutionary Implications Of Environmental Change Across Heterogeneous Landscapes, Jared J. Homola

Electronic Theses and Dissertations

Species use a variety of mechanisms to adapt to environmental change. These range from spatially tracking optimal environments, to phenotypically plastic responses and evolutionary adaptation. Due to increases in anthropogenic influence on environments, characteristics of change such as their duration and magnitude are undergoing fundamental shifts away from the natural disturbance regimes that shaped species’ evolution. This dissertation uses empirical data and simulation models to examine the ecological and evolutionary consequences of environmental change across real, heterogeneous landscapes for multiple species, with an emphasis on anthropogenic changes. I used landscape genetics to evaluate the effects of urbanization on two native …

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Using Environmental Dna And Occupancy Modeling To Examine Drivers Of Eastern Hellbender Extirpation And Sampling Method Efficiency In West Virginia, Sean Michael Wineland Jan 2018

Using Environmental Dna And Occupancy Modeling To Examine Drivers Of Eastern Hellbender Extirpation And Sampling Method Efficiency In West Virginia, Sean Michael Wineland

Theses, Dissertations and Capstones

Amphibian population declines and range constrictions are widespread but poorly understood. Effective conservation planning relies on accurate distribution data to develop a fundamental understanding of causal changes in species distributions. However, conventional detection methods for cryptic and elusive amphibians suffer from imperfect detection. Environmental DNA (eDNA) has emerged as an innovative and powerful conservation tool for detecting aquatic species presence; however comparative studies aimed at fully understanding eDNA detection probabilities are lacking. In this study, I used environmental DNA (eDNA) sampling methods and detailed historical records to identify drivers of extirpation and sampling method efficiency for an imperiled, long-lived giant …

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Influence Of Developmental Stage, Habitat, And Captivity On Thecutaneous Bacterial Communities Of Eastern Hellbenders (Cryptobranchus Alleganiensis Alleganiensis) In West Virginia, Rachel Fern Arrick Jan 2018

Influence Of Developmental Stage, Habitat, And Captivity On Thecutaneous Bacterial Communities Of Eastern Hellbenders (Cryptobranchus Alleganiensis Alleganiensis) In West Virginia, Rachel Fern Arrick

Theses, Dissertations and Capstones

Microbes inhabit virtually all surfaces of multicellular animal hosts, with microbial cells outnumbering the hosts’ own cells 10:1. Symbiont microbes, collectively referred to as the microbiome, can have profound impacts on the metabolism, development, behavior, and disease resistance of their multicellular hosts. Because the community structure of symbiont bacteria can influence host health, the characterization of amphibian microbiomes is becoming an increasingly important tool for future conservation in the face of global amphibian declines. Eastern hellbenders are good candidates for a microbiome study because they have seen substantial declines in recent decades and learning more about the environmental and physiological …

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Behavioral Differences Between Native And Exotic Invertebrate Prey Affect Susceptibility To Predation By A Native Amphibian Predator, Zachary Cava Aug 2016

Behavioral Differences Between Native And Exotic Invertebrate Prey Affect Susceptibility To Predation By A Native Amphibian Predator, Zachary Cava

Biology Theses

Invasive species threaten global biodiversity via mechanisms that include altering the dynamics and structure of native food webs. Whereas much research has focused on how exotic species respond to native predators, less is known about how native predators are affected by invasive prey. Here I investigate the response of a rare and threatened native predator—the Eastern Hellbender (Cryptobranchus alleganiensis) to a high-profile invasive crayfish species, Orconectes rusticus. Hellbenders have declined throughout much of their range, and although the potential for exotic predators (i.e. sport fish) to negatively impact C. alleganiensis has been addressed, effects of exotic prey …

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The Interactive Effects Of Pesticide Exposure And Infectious Disease On Amphibian Hosts, Katherine M. Pochini Aug 2016

The Interactive Effects Of Pesticide Exposure And Infectious Disease On Amphibian Hosts, Katherine M. Pochini

Open Access Theses

Natural systems are home to a multitude of natural and anthropogenic stressors, which draw an array of effects on ecological communities. While these effects have been investigated individually, it is important, given the routine co-occurrence of these stressors, to understand their interactive effects. Pesticide exposure and infectious disease are two common, co-occurring stressors that each have documented detrimental effects on species and, as evidence suggests, may have interactive effects. Moreover, existing research suggests that these interactive effects are highly context dependent, eliciting different results based on species, disease agent, toxin, and environment. Given the variability with which species may experience …

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Predicting Suitable Habitat Decline Of Midwestern United States Amphibians And Quantifying The Consequence Of Declines Using Pond-Breeding Salamanders, Brock Struecker Jan 2016

Predicting Suitable Habitat Decline Of Midwestern United States Amphibians And Quantifying The Consequence Of Declines Using Pond-Breeding Salamanders, Brock Struecker

Master's Theses

With current declines of vertebrate taxa meeting or exceeding those of historic mass extinction events, there is a growing need to investigate the main drivers of declines. Amphibians are perhaps at greatest risk of global climate change and land-use changes than most other vertebrate classes and also have significant roles in ecosystem processes – combined, this creates a cause for concern. I designed a study that would investigate the effects of current and predicted climate change and land-use changes on amphibians using species distribution models and a field study to identify the potential consequences of amphibian species declines by investigating …

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Comparative Analysis Of Anti-Bd Bacteria From Six Malagasy Frog Species Of Ranomafana National Park, Kelsey Savage May 2015

Comparative Analysis Of Anti-Bd Bacteria From Six Malagasy Frog Species Of Ranomafana National Park, Kelsey Savage

Senior Honors Projects, 2010-2019

As Malagasy amphibians are facing an impending extinction crisis from the lethal skin fungus Batrachochytrium dendrobatidis (Bd), it has become imperative to proactively mitigate the threat. Bd sporangia develop in the skin of infected amphibians and cause the skin to thicken, leading to ionic imbalance and eventual heart failure. It has been shown that certain bacterial species are able to inhibit Bd growth on amphibians by producing antifungal metabolites. Community-based probiotics are one approach used to combat chytridomycosis by inoculating an environment with Bd-inhibitory bacteria so that many amphibian species are treated at once. With this method, it is important …

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Effects Of Petroleum Distillates On Amphibian Development, Kate Walker May 2014

Effects Of Petroleum Distillates On Amphibian Development, Kate Walker

Graduate Theses and Dissertations

Petroleum distillates are widely used as an energy source and the extraction and disposal of these chemicals are done with little consideration of their effects on aquatic environments. Amphibians are considered excellent ecological indicators but little research has examined effects of petroleum distillates on aquatic species. I evaluated the lethal and sublethal effects on larval amphibians with exposure to petroleum distillates associated with various venues of pollution including hydraulic fracturing. I selected three petroleum distillates (kerosene, oil, and unleaded gasoline) that are known to have negative effects on aquatic organisms and are similar to the common constituents of mixtures used …

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Relationships Between Isolating Land Use And Amphibian Populations In Sub-Boreal Peatlands Of The Midwestern United States, Jeana Rose Albers Jan 2014

Relationships Between Isolating Land Use And Amphibian Populations In Sub-Boreal Peatlands Of The Midwestern United States, Jeana Rose Albers

All Graduate Theses, Dissertations, and Other Capstone Projects

Successful conservation efforts of amphibians depend on the knowledge of habitat preferences because the biggest threat to amphibian populations is considered to be habitat loss. Sub-boreal peatlands in the Midwest may be a refuge for amphibian populations, but little is known about the flora and fauna of these peatlands. My study examined amphibian species richness and species diversity in 17 sub-boreal peatlands in Minnesota and Wisconsin in 2011 and 2012. I assessed the relationship between land use of lands adjacent to peatlands and use of those peatlands by amphibian populations at three spatial scales by examining landscapes surrounding peatlands in …

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Diffuse Interactions Between Symbiotic Bacteria And Salamanders, Amanda Lee Allison Aug 2012

Diffuse Interactions Between Symbiotic Bacteria And Salamanders, Amanda Lee Allison

Masters Theses

A growing body of evidence indicates that all animals and plants have intimate associations (symbioses) with microbes. Scientific opinion has shifted from viewing microbes primarily as pathogens to the idea that healthy animals and plants carry specialized communities of coevolving microorganisms. However, the generality of this proposition is unknown because surveys rarely compare host-associated microbial assemblages with those of similar host species or free-living assemblages in relevant microhabitats. To evaluate the specificity and consistency of microbial associations in salamanders, I analyzed just over 3.6 million 16S ribosomal RNA gene sequences from paired samples from host-associated bacteria on the skin of …

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Ecogeographical Distribution Of The Herpetofauna Of Indio Mountains Research Station, Hudspeth County, Texas, Ross Owen Couvillon Jan 2011

Ecogeographical Distribution Of The Herpetofauna Of Indio Mountains Research Station, Hudspeth County, Texas, Ross Owen Couvillon

Open Access Theses & Dissertations

Indio Mountain Research Station (IMRS) in Trans-Pecos, Texas is dominated by Chihuahuan Desert scrub vegetation, but a complexity of plant communities exist relating to elevation, slope, and geologic formations. Surrounding the Indio Mountains are desert grasslands with various desert scrub associations. This mosaic of habitats forms a unique assemblage of amphibians and reptiles. The goal of this study was to determine if the current number of amphibians, turtles, lizards, and snakes (43 species) of IMRS was accurate and identify which biotic and abiotic factors define the distribution of these species. Records from the last approximately 25 years were used to …

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Population And Conservation Genetics Of Crawfish Frogs, Lithobates Areolatus, At Their Northeastern Range Limits, Schyler O. Nunziata Jan 2011

Population And Conservation Genetics Of Crawfish Frogs, Lithobates Areolatus, At Their Northeastern Range Limits, Schyler O. Nunziata

Online Theses and Dissertations

Crawfish Frogs (Lithobates areolatus) are state endangered in Indiana and Iowa, with populations in decline throughout their range. I studied populations of Crawfish Frogs on local and statewide scales at their northeastern range limits to (1) assess the level of genetic diversity within populations (2) estimate fine-scale genetic structure, and (3) estimate genetic differentiation between populations at the state level. Crawfish Frogs breed in temporary pools and wetlands, and have high breeding-pond fidelity; therefore I predicted to find genetic differences between ponds at small geographic scales. I used 10 microsatellite loci to genotype frogs collected from three primary populations in …

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Evaluating Ecological Restoration In Tennessee Hardwood Bottomland Forests, Elizabeth Anne Summers Aug 2010

Evaluating Ecological Restoration In Tennessee Hardwood Bottomland Forests, Elizabeth Anne Summers

Masters Theses

Hardwood bottomland ecosystems provide critical habitat for various wildlife among numerous ecosystem services. Since the 1800s, these forested wetlands have been logged and drained for agriculture. The federal government passed a series of legislative acts that protected wetlands and provided monetary support for restoration. The Wetlands Reserve Program (WRP) was established in 1990 with the goal of restoring ecological function in wetlands. Although several studies have measured plant and wildlife responses to WRP restorations, no standard protocol has been developed to monitor the state of ecological restoration at sites. Index of biotic integrity (IBI) models are commonly used to evaluate …

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Systematics Of The Genus Ptychadena Boulenger, 1917 (Anura: Ptychadenidae) From Democratic Republic Of The Congo, Katrina Marie Weber Jan 2010

Systematics Of The Genus Ptychadena Boulenger, 1917 (Anura: Ptychadenidae) From Democratic Republic Of The Congo, Katrina Marie Weber

Open Access Theses & Dissertations

This thesis increases the scope of previous phylogenetic analyses that revealed high levels of genetic differentiation within the anuran genus Ptychadena. Herein, I increase sampling of Central African populations of Ptychadena by over six times to examine their relationships to other African populations and to search for cryptic species. This study represents the most comprehensive molecular phylogeny of Ptychadena to date. A total of three mitochondrial (12S, 16S, and cyt b) and two nuclear (RAG1 and rhodopsin) genes were sequenced for 67 specimens of Ptychadena. Maximum parsimony, maximum likelihood, and Bayesian analyses were conducted. These analyses revealed …

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