Current Search: Hughes, Colin (x)
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- Title
- Breeding sex ratios of three imperiled marine turtles nesting in southern Florida.
- Creator
- Lasala, Jacob, Hughes, Colin, Wyneken, Jeanette, Graduate College
- Abstract/Description
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Sound assessment of the status of a threatened or endangered organism depends on understanding key aspects of behavior throughout its life history. Sometimes organisms can be difficult to observe and key aspects of behavior may not be accessed directly. Alternative assessment techniques include using molecular markers to identify fundamental relationships among males and females. In the context of assessing the status of imperiled populations’ sex ratios, population size and the relatedness...
Show moreSound assessment of the status of a threatened or endangered organism depends on understanding key aspects of behavior throughout its life history. Sometimes organisms can be difficult to observe and key aspects of behavior may not be accessed directly. Alternative assessment techniques include using molecular markers to identify fundamental relationships among males and females. In the context of assessing the status of imperiled populations’ sex ratios, population size and the relatedness of the individuals are important metrics. Environmental sex determination directs developing marine turtle sex so that primary sex ratios depend upon weather and climate; those sex ratios are estimated by proxies. Adult population sizes are inferred from numbers of females nesting on the beach, but numbers of males are unknown. Male breeding population size can be estimated from subtracting maternal genotypes from genotypes of offspring exclusion analyses. The resulting adult sex ratios differ greatly from those estimated for hatchlings. To refine current adult sex ratios in ways that are relevant to production of future generations and add to our understanding of effective population size we compare the breeding sex ratios the number of males and females contributing to a population of three species of sea turtles nesting in southern Florida. We will use the same genetic data to measure relatedness of the female nesters and the male contributors and describe how that relates to genetic flow and population structure.
Show less - Date Issued
- 2015
- PURL
- http://purl.flvc.org/fau/fd/FA00005893
- Format
- Document (PDF)
- Title
- The effect of parasite infection on reproductive potential of bony fish.
- Creator
- Young, Joy M., Whittington, Jim, Graduate College, Hughes, Colin
- Abstract/Description
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Accurate predictions of population growth, including reproduction, are vital for the effective management of fisheries. However, factors effecting reproductive potential in boney fishes are not entirely understood. In several species of fish, parasite infection has been associated with decreased fecundity including fewer and smaller eggs, shortened spawning season, and decreased larval survival. We examined the effect of parasite infection and life history parameters on egg quality of 40...
Show moreAccurate predictions of population growth, including reproduction, are vital for the effective management of fisheries. However, factors effecting reproductive potential in boney fishes are not entirely understood. In several species of fish, parasite infection has been associated with decreased fecundity including fewer and smaller eggs, shortened spawning season, and decreased larval survival. We examined the effect of parasite infection and life history parameters on egg quality of 40 spawning capable female common snook, Centropomus undecimalis, collected from 3 inlets on the Atlantic coast of Florida in the summer of 2013. Egg quality was measured as fatty acid DHA, PI, and EPA composition of eggs. Six major taxons of parasites were identified: Cestoda 1 adult, 68 trypanorhyncha larvae, Copepoda 1 Lernae sp., 62 Lernanthropus sp., Digenea 1 adult, Monogenea 1 adult, Nematoda 861 Contracecum sp., and Pentastomida 36 Sebekia sp.. In addition, dead parasites of unknown taxa 262 total were counted. Parasite infracommunities were described as total number of live parasites per individual, total number of dead parasites per individual, the Shannon Wiener Index H as a measure of diversity, and the Berger-Parker Index BPI as a measure of numerical dominance. Total number of dead parasites and BPI had a significant, negative effect on percent composition of DHA of eggs. Individuals with higher amounts of dead parasites 20 were predicted to drop below a 13 DHA composition threshold needed for hatching and larval success.
Show less - Date Issued
- 2014
- PURL
- http://purl.flvc.org/fau/fd/FA00005174
- Format
- Document (PDF)
- Title
- Variation in the Major Histocompatibility Gene is Maintained By Selection Imposed By Infectious Disease.
- Creator
- Blair, Zizah J., Hughes, Colin, Charles E. Schmidt College of Science
- Abstract/Description
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Major Histocompatibility (MH) genes play critical roles in mounting adaptive immune responses to infectious diseases and parasites. There are two classes of MH genes: Class I and II; Class II can be further divided into Class II A and II B genes, this study focuses on Class IIB. Class II B genes are exceptionally variable in sequence. Leading hypotheses propose that this genetic variation is maintained by selection for resistance to pathogens. Since pathogens are constantly evolving to avoid...
Show moreMajor Histocompatibility (MH) genes play critical roles in mounting adaptive immune responses to infectious diseases and parasites. There are two classes of MH genes: Class I and II; Class II can be further divided into Class II A and II B genes, this study focuses on Class IIB. Class II B genes are exceptionally variable in sequence. Leading hypotheses propose that this genetic variation is maintained by selection for resistance to pathogens. Since pathogens are constantly evolving to avoid detection, and new pathogens regularly enter populations, which MH proteins confer immunity fluctuates over time. This study examines MH Class II B in Centropomus undecimalis, the common Snook. Genes will be sequenced, and their variability quantified using approaches that include: database searches (NCBI), PCR, and sequencing. Sequencing of the MH gene will provide insight on how high polymorphism results from immune responses to infectious pathogens.
Show less - Date Issued
- 2015
- PURL
- http://purl.flvc.org/fau/fd/FA00005177
- Subject Headings
- College students --Research --United States.
- Format
- Document (PDF)
- Title
- Polymorphism and selection at exon 2 of the class II beta chain of the major histocompatibility complex in Forpus passerinus.
- Creator
- Walbroehl, Jaclyn M., Florida Atlantic University, Hughes, Colin
- Abstract/Description
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Female mate choice has been proposed to be a major force acting to maintain the polymorphism of the MHC, the most genetically variable genes known. I genotyped seventy-two individuals from a free-living population of the parrot, Forpus passerinus, in order to determine whether disassortative mating is the mode of selection acting at this locus. Both the high rate of nonsynonymous amino acid changes at the peptide binding regions of exon 2 of the class II beta gene and the unprecedented number...
Show moreFemale mate choice has been proposed to be a major force acting to maintain the polymorphism of the MHC, the most genetically variable genes known. I genotyped seventy-two individuals from a free-living population of the parrot, Forpus passerinus, in order to determine whether disassortative mating is the mode of selection acting at this locus. Both the high rate of nonsynonymous amino acid changes at the peptide binding regions of exon 2 of the class II beta gene and the unprecedented number of alleles found in this population provided strong evidence for the operation of selection. Despite this, a chi-square test revealed no evidence of disassortative mating for this sample, X2=0.569, n.s. I propose that natural selection, not sexual selection, must be operating at this locus to maintain the degree of variation found in 270 base-pairs of this gene.
Show less - Date Issued
- 2006
- PURL
- http://purl.flvc.org/fcla/dt/13405
- Subject Headings
- Immunogenetics, Genetic polymorphisms, Major histocompatibility complex--Genetic aspects
- Format
- Document (PDF)
- Title
- Aggressive Behaviors Of Adult Male Atlantic Spotted Dolphins (Stenella frontalis) During Intraspecific And Interspecific Aggressive Interactions.
- Creator
- Volker, Cassandra L., Herzing, Denise L., Hughes, Colin, Florida Atlantic University, Charles E. Schmidt College of Science, Department of Biological Sciences
- Abstract/Description
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Atlantic spotted dolphins (Stenella frontalis) and bottlenose dolphins (Tursiops truncatus) are two sympatric species resident to the Bahamas. The visibility of the Bahamian water provided a unique opportunity to study spotted dolphin communication during aggression. This study’s main focus was to decipher any similarities or differences in the behaviors used by spotted dolphins during interspecific and intraspecific aggression. Both similarities and differences were discovered. Biting,...
Show moreAtlantic spotted dolphins (Stenella frontalis) and bottlenose dolphins (Tursiops truncatus) are two sympatric species resident to the Bahamas. The visibility of the Bahamian water provided a unique opportunity to study spotted dolphin communication during aggression. This study’s main focus was to decipher any similarities or differences in the behaviors used by spotted dolphins during interspecific and intraspecific aggression. Both similarities and differences were discovered. Biting, following, and chasing behavioral events were used more during interspecific aggression, while the display behavioral class was used more than the contact behavioral class during intrabut not interspecific aggression. This study showed that spotted dolphins use more energy intensive and risky behaviors when fighting interspecifically. This could result from having to fight and defend females from a larger species, trying to avoid sexual harassment from bottlenose males, or needing to use behaviors that are more overt and easily understood during interspecies communication.
Show less - Date Issued
- 2016
- PURL
- http://purl.flvc.org/fau/fd/FA00004638, http://purl.flvc.org/fau/fd/FA00004638
- Subject Headings
- Atlantic spotted dolphin--Bahamas., Aggressive behavior in animals., Social behavior in animals., Aquatic mammals--Behavior., Predation (Biology), Predatory marine animals--Ecology.
- Format
- Document (PDF)
- Title
- FOOD WEB MODELING TO ASSESS INTERACTIONS BETWEEN ARTIFICIAL REEFS AND NATURAL REEFS.
- Creator
- McNamee, Elizabeth A., Hughes, Colin, Florida Atlantic University, Department of Environmental Sciences, Charles E. Schmidt College of Science
- Abstract/Description
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The effect of artificial reefs on natural reefs is poorly understood. This study focused on Aquarius Reef Base (ARB), an underwater habitat offshore of Key Largo, Florida, and 14 natural reef sites spanning 4 habitats, on the surrounding Conch Reef. Food web models were created for ARB and natural reef habitats. Biomass at each habitat was quantified by fish surveys. Using Ecopath, species were organized into functional groups with supporting data from previous research for other inputs. ARB...
Show moreThe effect of artificial reefs on natural reefs is poorly understood. This study focused on Aquarius Reef Base (ARB), an underwater habitat offshore of Key Largo, Florida, and 14 natural reef sites spanning 4 habitats, on the surrounding Conch Reef. Food web models were created for ARB and natural reef habitats. Biomass at each habitat was quantified by fish surveys. Using Ecopath, species were organized into functional groups with supporting data from previous research for other inputs. ARB’s food web was found to have a large predator biomass with insufficient prey biomass to sustain the population, suggesting that these predators must forage on nearby natural reefs where the predator/prey ratio is smaller. Between 0.57km2 and 1.79km2 of natural reef is estimated to be a sufficient spatial subsidy for the large predatory biomass at ARB when the biomass is added as determined by the seascape around the artificial reef.
Show less - Date Issued
- 2021
- PURL
- http://purl.flvc.org/fau/fd/FA00013798
- Subject Headings
- Artificial reefs, Coral reefs, Food chains (Ecology)
- Format
- Document (PDF)
- Title
- Effects of parasitism on the reproduction of common snook.
- Creator
- Young, Joy M., Hughes, Colin, Florida Atlantic University, Charles E. Schmidt College of Science, Department of Biological Sciences
- Abstract/Description
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The effect of parasitism on the individual, and on a population, is one of the least understood and poorly studied areas of fish ecology. Parasites compete for maternal energetic reserves required for the production of viable eggs and offspring; thus parasites can directly influence population dynamics by lowering the number of offspring that survive to produce. The goal of this work was to explore the effect of parasitism on the reproductive potential of fish. Traditional measures of somatic...
Show moreThe effect of parasitism on the individual, and on a population, is one of the least understood and poorly studied areas of fish ecology. Parasites compete for maternal energetic reserves required for the production of viable eggs and offspring; thus parasites can directly influence population dynamics by lowering the number of offspring that survive to produce. The goal of this work was to explore the effect of parasitism on the reproductive potential of fish. Traditional measures of somatic energy reserves and body condition were examined along with newer measures of fatty acids present in eggs to approximate reproductive potential. Eighty female common snook, Centropomus undecimalis, were collected during spawning season (mid April to mid October) from four spawning aggregations along the southeastern coast of Florida and examined for a suite of biological, reproductive, and parasite infection measures. General linear models were used to model somatic indices, body condition, fatty acid composition and the ratios of fatty acids in eggs as a function of parasite infection parameters, host age, capture location, capture month and year. All fish were included in the somatic indices and body condition analysis while a subset of 40 fish were used in the analysis on fatty acid composition and the ratios of fatty acids in eggs.
Show less - Date Issued
- 2015
- PURL
- http://purl.flvc.org/fau/fd/FA00004424, http://purl.flvc.org/fau/fd/FA00004424
- Subject Headings
- Aquaculture -- Environmental aspects, Centropomus undecimalis -- Physiology, Fish culture -- Health aspects, Fishes -- Ecophysiology, Parasitism, Snook -- Development, Snook -- Physiology
- Format
- Document (PDF)
- Title
- Identifying mating systems of imperiled marine turtles nesting in southern Florida through exclusion analysis to estimate the breeding sex ratio.
- Creator
- Lasala, Jacob A., Wyneken, Jeanette, Hughes, Colin, Florida Atlantic University, Charles E. Schmidt College of Science, Department of Biological Sciences
- Abstract/Description
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The reproductive behavior of migratory organisms is difficult to characterize as the mating behavior can be difficult to observe. For some species, one sex can be readily observable, but the other may remain hidden, confounding attempts to assess population demographics. For such species, it can be difficult to determine the sex ratio of the population. Without accurate accounts of the numbers of males and females, conservation methods may be insufficient and their performance unclear....
Show moreThe reproductive behavior of migratory organisms is difficult to characterize as the mating behavior can be difficult to observe. For some species, one sex can be readily observable, but the other may remain hidden, confounding attempts to assess population demographics. For such species, it can be difficult to determine the sex ratio of the population. Without accurate accounts of the numbers of males and females, conservation methods may be insufficient and their performance unclear. Alternative methods of measuring sex ratios therefore must be used to estimate the number of individuals and assess breeding behavior. Here I identified breeding sex ratios (BSR) measured using paternity analysis of offspring through exclusion analysis to quantify the numbers of males contributing. Here I discuss the mating behavior of three species of marine turtle that nest in southern Florida: the loggerhead (Caretta caretta), the leatherback (Dermochelys coriacea), and the green sea turtle (Chelonia mydas) at three beaches (Boca Raton, Juno Beach, and Sanibel Island) from 2013-2017; over 400 nesting females were identified and genotyped and almost 7,000 hatchlings were collected and genotyped. Females from all three species successfully mated with more than one male in all years analyzed demonstrating multiple paternity of clutches. For loggerheads, many male genotypes were identified, suggesting that females likely mate en route to their nesting grounds, inducing a male-biased BSR. Examination of females that were sampled more than once per season (repeats), evidence of sperm storage was found for all nests and some turtles might mate in between nesting events. Leatherback females displayed a higher rate of multiple paternity than was previously published for other Caribbean nesting sites; I hypothesize that this result may be due to a mainland nesting beach effect. The leatherback BSR over all years was approximately 1:1, and one male was identified fathering than two different females’ nests (polygyny). For green turtles, multiple paternity was found and there was evidence of polygyny. Across all three species, evidence for indirect benefits of mating multiply (hatching success or larger hatchlings) was weak or not supported. Together, the four studies contribute to the overall body of reproductive behavior studies.
Show less - Date Issued
- 2018
- PURL
- http://purl.flvc.org/fau/fd/FA00013161
- Subject Headings
- Sea turtles--Florida, Mating behavior, Sex ratio
- Format
- Document (PDF)
- Title
- Risk assessment of the nonnative Argentine black and white Tegu, Salvator merianae, in South Florida.
- Creator
- Barraco, Liz Anne, Hughes, Colin, Florida Atlantic University, Charles E. Schmidt College of Science, Department of Biological Sciences
- Abstract/Description
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The Argentine black and white tegu, Salvator merianae, is a nonnative species that has invaded parts of Florida. The potential impacts of this species on native Florida wildlife are not yet known. This study looks at the stomach contents of 169 S. merianae captured between 2011 and 2013 in south Florida to infer potential impacts of S. merianae and spatial or seasonal shifts in diet. Analysis of 169 GI tracts showed that S. merianae is an omnivorous, terrestrial forager with a broad dietary...
Show moreThe Argentine black and white tegu, Salvator merianae, is a nonnative species that has invaded parts of Florida. The potential impacts of this species on native Florida wildlife are not yet known. This study looks at the stomach contents of 169 S. merianae captured between 2011 and 2013 in south Florida to infer potential impacts of S. merianae and spatial or seasonal shifts in diet. Analysis of 169 GI tracts showed that S. merianae is an omnivorous, terrestrial forager with a broad dietary range which includes insects, fruits, plants, snails, crayfish, carrion, birds, small mammals, turtles, snakes, lizards, frogs and eggs. S. merianae diet composition varied with capture habitat, the fattest tegus were collected from disturbed/agricultural areas and these samples contained, primarily, gastropods and insects. Tegu dietary habits threaten local endangered and state listed species such as the American crocodile, Crocodylus acutus, and the Cape Sable seaside sparrow, Ammodramus maritimus mirabilis. Dedicated funds and efforts need to be focused on this species to limit its further spread and future impact on native species.
Show less - Date Issued
- 2015
- PURL
- http://purl.flvc.org/fau/fd/FA00004344, http://purl.flvc.org/fau/fd/FA00004344
- Subject Headings
- Adaptation (Biology), Ecological risk assessment -- Florida, Introduced reptiles -- Florida -- Identification, Lizards -- Florida -- Identification, Nonindigenous pests -- Geographical distribution, Predation (Biology)
- Format
- Document (PDF)
- Title
- Site Fidelity Assessment of Atlantic Bottlenose Dolphins (Tursiops truncatus) Following Large-Scale Emigration of Sympatric Atlantic Spotted Dolphins (Stenella frontalis) in the Bahamas.
- Creator
- Kuhn, Sommer L., Herzing, Denise L., Hughes, Colin, Florida Atlantic University, Charles E. Schmidt College of Science, Department of Biological Sciences
- Abstract/Description
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Two sympatric species of dolphins (Atlantic spotted dolphins, Stenella frontalis and Atlantic bottlenose dolphins, Tursiops truncatus) have been long-term residents to Little Bahama Bank. This study assessed whether there was a change in residence patterns or diurnal foraging depths of bottlenose dolphins following a large emigration event in the resident spotted dolphin community on this sandbank. Photo-identification was used to identify individual bottlenose dolphins and compare pooled...
Show moreTwo sympatric species of dolphins (Atlantic spotted dolphins, Stenella frontalis and Atlantic bottlenose dolphins, Tursiops truncatus) have been long-term residents to Little Bahama Bank. This study assessed whether there was a change in residence patterns or diurnal foraging depths of bottlenose dolphins following a large emigration event in the resident spotted dolphin community on this sandbank. Photo-identification was used to identify individual bottlenose dolphins and compare pooled years before (2010-2012) and after (2013-2015) the spotted dolphin emigration. The identified community size and overall residency of the bottlenose dolphins remained similar, although two bottlenose dolphins emigrated over deep water to the site spotted dolphins emigrated. Bottlenose dolphins diurnally fed in shallower water but remained in the same geographic foraging locations. Reasons remain unknown for this depth change, but potential changes in the productivity of primary bottlenose dolphin foraging habitats or reduction of spotted dolphins from shallower depths remain possibilities.
Show less - Date Issued
- 2017
- PURL
- http://purl.flvc.org/fau/fd/FA00004927, http://purl.flvc.org/fau/fd/FA00004927
- Subject Headings
- Bottlenose dolphin--Habitat--Bahamas--Little Bahama Bank., Bottlenose dolphin--Effect of habitat modification on., Atlantic spotted dolphin--Habitat--Bahamas--Little Bahama Bank., Dolphins--Atlantic Ocean--Geographical distribution., Social behavior in animals.
- Format
- Document (PDF)
- Title
- ARE SOUTH FLORIDA’S GOPHER TORTOISE POPULATION’S GENETICALLY DIFFERENTIATED FROM EACH OTHER?.
- Creator
- Rothberg, Olivia, Frazier, Evelyn, Hughes, Colin, Florida Atlantic University, Department of Biological Sciences, Charles E. Schmidt College of Science
- Abstract/Description
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Gopher Tortoises are an imperiled terrestrial tortoise considered ecosystem engineers, as their burrows support over 350 species of “commensals”. Due to extensive anthropogenic habitat destruction and fragmentation, tortoise populations have significantly declined over the past 100 years. This isolation is leading to a premature loss of genetic variation, further precipitating the decline of this species. Understanding the genetic structure of this species can aid management decisions through...
Show moreGopher Tortoises are an imperiled terrestrial tortoise considered ecosystem engineers, as their burrows support over 350 species of “commensals”. Due to extensive anthropogenic habitat destruction and fragmentation, tortoise populations have significantly declined over the past 100 years. This isolation is leading to a premature loss of genetic variation, further precipitating the decline of this species. Understanding the genetic structure of this species can aid management decisions through intentionally relocating animals based on genetic units and historic gene flow, to preserve adaptive diversity and evolutionary potential on a large scale. I investigated whether Southeast Florida has a genetically distinct subpopulation of Gopher Tortoises in the unexamined southeasternmost extent of their range, from Palm Beach to Miami-Dade counties, using 9 microsatellite loci previously characterized for this species (Schwartz et al 2003) and found that our populations are only modestly differentiated from each other, and have greater genetic diversity than other populations.
Show less - Date Issued
- 2023
- PURL
- http://purl.flvc.org/fau/fd/FA00014362
- Subject Headings
- Gopher tortoises, Florida, South, Population genetics
- Format
- Document (PDF)