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Reproduction

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Articles 31 - 60 of 110

Full-Text Articles in Ecology and Evolutionary Biology

Influence Of Testosterone On Male-Male Competition In The Red-Sided Garter Snake, Thamnophis Sirtalis Parietalis, Isabella M. G. Bukovich Dec 2020

Influence Of Testosterone On Male-Male Competition In The Red-Sided Garter Snake, Thamnophis Sirtalis Parietalis, Isabella M. G. Bukovich

Senior Honors Projects, 2020-current

Female mimicry in the red-sided garter snake, Thamnophis sirtalis parietalis, is described in several well-studied evolutionary advantages, but an aspect that remains elusive is how reproductive traits are linked to the 3-fold higher circulating androgens in males with this phenotype. In this study, we implanted male garter snakes (n=15 per group) with either a blank implant (SHAM; control) or a T implant, the latter simulating the female mimic phenotype. Following simulated low-temperature dormancy, males were scored for courtship intensity over three days of behavioral trials with females housed in the same facility. Males were sacrificed, and sperm were collected …

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Effects Of Long-Term Variation In Temperature On Reproductive Phenology In A Population Of Eastern Bluebirds (Sialia Sialis), Paul Pleiman Dec 2020

Effects Of Long-Term Variation In Temperature On Reproductive Phenology In A Population Of Eastern Bluebirds (Sialia Sialis), Paul Pleiman

Graduate Theses and Dissertations

This study investigates the relationship between multiple temperature variables, to include annual and pre-lay date temperatures with first-egg and mean first-egg lay dates of the eastern bluebird at the Warner Parks in Nashville, Tennessee, USA. Data is collected by citizen scientists for the Eastern Bluebird Nesting Box Project while visiting artificial nest boxes throughout the park and recording observations made during the breeding season. Temperature data is retrieved from the Northwest Alliance for Computational Science and Engineering’s Parameter-elevation Regressions on Independent Slopes Model (PRISM) Climate Group, based at Oregon State University. The analyses showed no correlation between annual or pre-lay …

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Reproductive Compatibility Among Populations And Host‐Associated Lineages Of The Common Bed Bug (Cimex Lectularius L.), Zachary C. Devries, Richard G. Santangelo, Warren Booth, Christopher G. Lawrence, Ondřej Balvín, Tomáš Bartonička, Coby Schal Oct 2020

Reproductive Compatibility Among Populations And Host‐Associated Lineages Of The Common Bed Bug (Cimex Lectularius L.), Zachary C. Devries, Richard G. Santangelo, Warren Booth, Christopher G. Lawrence, Ondřej Balvín, Tomáš Bartonička, Coby Schal

Entomology Faculty Publications

As populations differentiate across geographic or host‐association barriers, interpopulation fertility is often a measure of the extent of incipient speciation. The bed bug, Cimex lectularius L., was recently found to form two host‐associated lineages within Europe: one found with humans (human‐associated, HA) and the other found with bats (bat‐associated, BA). No unequivocal evidence of contemporary gene flow between these lineages has been found; however, it is unclear whether this is due to an inability to produce viable “hybrid” offspring. To address this question and determine the extent of compatibility between host‐associated lineages, we set up mating crosses among populations of …

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Reproductive Effort Of Montastraea Cavernosa Across Depth In The Context Of Both Climate Change Refugia And Emergent Disease, Jeanne Bloomberg Jul 2020

Reproductive Effort Of Montastraea Cavernosa Across Depth In The Context Of Both Climate Change Refugia And Emergent Disease, Jeanne Bloomberg

LSU Master's Theses

As coral populations on shallow reefs decline globally, mesophotic coral ecosystems (MCE) have been suggested as potential coral refugia in the face of climate changes, leading to the development of a comprehensive deep reef refugia hypothesis. The current study assesses the climate and disease refuge potential of MCEs in the U.S. Virgin Islands (USVI) for the gonochoric, broadcast-spawning species Montastraea cavernosa. Polyp, population, and total habitat fecundities were estimated across the species’ depth range, and changes to population oocyte production over time due to recent ecosystem disturbances were considered. The number of gonads producing oocytes in each polyp and oocyte …

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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 …

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Evaluation Of Space Use And Movement By Wild Turkey (Meleagris Gallopavo) During Extreme Climatic Disturbances And Annual Phenological States, David J. Moscicki Jan 2020

Evaluation Of Space Use And Movement By Wild Turkey (Meleagris Gallopavo) During Extreme Climatic Disturbances And Annual Phenological States, David J. Moscicki

LSU Master's Theses

Space use is driven by both intrinsic and extrinsic factors across space and time. Meaning a species demography and habitat requirements may vary across landscapes. Recent studies on wild turkeys (Meleagris gallopavo spp., hereafter turkey) have shown both direct and indirect demographic impacts of climatically driven events on turkey populations. Similarly, there is an abundance of information documenting turkey demographic parameters and space use, but few studies have addressed breeding phenology in great detail. We evaluated the impact on space use and movement patterns of Eastern wild turkeys (M. g. silvestris; n = 20) and Rio Grande wild …

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Distribution And Reproduction By The Purple Gallinule (Porphyrio Martinica) In Arkansas, C. Renn Tumlison, Terry L. Tumlison, Tamzen T. Bryant Jan 2020

Distribution And Reproduction By The Purple Gallinule (Porphyrio Martinica) In Arkansas, C. Renn Tumlison, Terry L. Tumlison, Tamzen T. Bryant

Journal of the Arkansas Academy of Science

The Purple Gallinule (Porphyrio martinica) is a rare bird in Arkansas, and its populations likely have declined due to loss of marshy areas with emergent vegetation. By use of online sources for citizen science combined with a field study, we elucidate the current distribution of this bird in Arkansas, and document characteristics of reproduction and development. Purple Gallinules arrive in Arkansas as early as April and remain to late October. Nesting occurs from early May into July, and nests may represent second broods. Ontogenetic changes in hatchlings are described.

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Vertebrate Natural History Notes From Arkansas, 2020, C. Renn Tumlison, Matt Connior, Blake Sasse, Henry Robison, Stan Trauth, S Higdon, L Baer, Z. Baer, R. Stinson, D. Carson, T. Inebnit, L. Lewis, Roger Perry, Ron Redman Jan 2020

Vertebrate Natural History Notes From Arkansas, 2020, C. Renn Tumlison, Matt Connior, Blake Sasse, Henry Robison, Stan Trauth, S Higdon, L Baer, Z. Baer, R. Stinson, D. Carson, T. Inebnit, L. Lewis, Roger Perry, Ron Redman

Journal of the Arkansas Academy of Science

Smaller details of natural history often go undocumented to science if those details are not parts of larger studies, but small details can provide insights that lead to interesting questions about ecological relationships or environmental change. We have compiled recent important observations of distribution and reproduction of fishes and mammals. Included are new distributional records of mammals, and observations of reproduction in several mammals for which few data exist in Arkansas. A rare record of the Long-tailed weasel, a special of special concern in Arkansas, is documented from Newton Co. We also provide evidence that Seminole bats likely reproduce in …

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Competing Reproductive And Physiological Investments In An All‑Female Lizard, The Colorado Checkered Whiptail, Lise M. Aubry, Spencer B. Hudson, Bryan M. Kluever, Alison C. Webb, Susannah S. French Jan 2020

Competing Reproductive And Physiological Investments In An All‑Female Lizard, The Colorado Checkered Whiptail, Lise M. Aubry, Spencer B. Hudson, Bryan M. Kluever, Alison C. Webb, Susannah S. French

United States Department of Agriculture Wildlife Services: Staff Publications

Organisms in the wild have to allocate limited resources towards competing functions such as reproduction, growth, and self-maintenance. These competing investments create significant changes in physiological activity, and we still know little about the relationship between physiological activity and reproductive investment in natura. We investigated trade-offs between physiological activity and reproductive investment in the parthenogenetic Colorado checkered whiptail, Aspidoscelis neotesselata, across three different sites at the US Army Fort Carson Military Installation near Colorado Springs, CO, through-out the reproductive season in 2018 and 2019. We measured clutch size and reproductive activity and quantified plasma corticosterone (CORT), reactive oxygen metabolites (ROMs), …

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Assessment Of Indiana Bat Reproductive Condition, Recapture Trends, And Temperatures Of Artificial Roosts In Kentucky, Michaela L. Rogers Jan 2020

Assessment Of Indiana Bat Reproductive Condition, Recapture Trends, And Temperatures Of Artificial Roosts In Kentucky, Michaela L. Rogers

Online Theses and Dissertations

Recovery of bat species impacted by white-nose syndrome (WNS) will necessarily require population growth. I assessed reproductive capability of the endangered Indiana bat (Myotis sodalis) in Kentucky, where WNS was first detected in hibernacula in April 2011. Due to loss of fat reserves associated with WNS infection, coupled with the energetic expenditures associated with pregnancy, I hypothesized mass of reproductively-active females captured during the maternity season would decrease across my data collection period (2017-2019). Further, I predicted that reproductive rates in the study population would be lower than historic rates for Kentucky. Mist net surveys around artificial maternity roosts at …

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Influence Of Diet And Abiotic Factors On The Survival And Reproduction Of Calanoid Copepod Pseudodiaptomus Annandalei, Abd Aziz Fatin Fatihah Jan 2020

Influence Of Diet And Abiotic Factors On The Survival And Reproduction Of Calanoid Copepod Pseudodiaptomus Annandalei, Abd Aziz Fatin Fatihah

Student Works (2020-2029)

The calanoid copepod, Pseudodiaptomus annandalei, due to its good nutritional value and significance as a natural diet of many tropical fish, is a superior live feed for marine fish larvae. Fish larvae needs a sustainable supply of good quality live feed for optimal growth and survival. Aims of this study were to investigate the effects of (1) marine mircroheterotrophs grown in palm oil mill effluent (POME) as copepod diet and (2) abiotic factors i.e. salinity (ppt), temperature (˚C), pH, photoperiod and light intensity on the survival and nauplii production of P. annandalei. Both biotic and abiotic experiments were conducted with …

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Golden Eagle Resource Selection And Environmental Drivers Of Reproduction In The Northern Range Of Yellowstone National Park, David Brown Haines Jan 2020

Golden Eagle Resource Selection And Environmental Drivers Of Reproduction In The Northern Range Of Yellowstone National Park, David Brown Haines

Graduate Student Theses, Dissertations, & Professional Papers

In the United States (US), National Parks are considered the “crown jewels” of protected lands. However, the importance of National Parks to wildlife populations and the species that inhabit them is not often quantified, thus, requiring a better understanding of National Parks as a conservation tool. Golden eagles (Aquila chrysaetos) are a North American species of conservation concern and territories in the northern range of Yellowstone National Park (YNP) are relatively dense. However, average reproductive rates over the past ten years (2011-2020) have been low (productivity = 0.34, nest success = 28%). The contrast of high density and …

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Reproductive Parameters And Female Breeding Season Survival Of Rio Grande Wild Turkeys In South Central Texas, Jacob White Oct 2019

Reproductive Parameters And Female Breeding Season Survival Of Rio Grande Wild Turkeys In South Central Texas, Jacob White

LSU Master's Theses

Historically, Rio Grande wild turkeys in south central Texas have been at lower densities than other portions of the state. Within the Oak-Prairie Wildlife District of Texas, Rio Grande wild turkey regulatory restrictions are different for counties in the eastern and western portions of the ecoregion. Due to perceived increases in turkey density in the eastern portion of the ecoregion (hereafter 1-bird zone), Texas Parks and Wildlife Department (TPWD) considered increasing the bag limit to match counties in the western portion of the district (hereafter 4-bird zone) in order to increase hunting opportunities. However, if regulatory changes are to be …

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Recreation, Fire And Disease Create A Mosaic Of Threats For Golden Eagles In Southwestern Idaho, Caitlin Marie Davis Aug 2019

Recreation, Fire And Disease Create A Mosaic Of Threats For Golden Eagles In Southwestern Idaho, Caitlin Marie Davis

Boise State University Theses and Dissertations

Anthropogenic stressors have resulted in ecosystem impoverishment and biodiversity loss worldwide. As the strength and reach of the human footprint increases, investigation of the additive or interactive effects of synergistic stressors on the landscape is imperative for conserving ecosystems and species within them. Apex predators can reflect how stressors impact ecosystems because of bottom-up effects. Golden eagles (Aquila chrysaetos) are apex predators of North American sagebrush-steppe ecosystems that are impacted by a suite of stressors, including wildfire, outdoor recreation disturbance, and habitat loss. We investigated whether multiple threats had additive or interactive effects on golden eagle occupancy, reproduction, …

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Developmental And Reproductive Characteristics Of Beef Heifers Classified By Number Of Estrous Cycles Experienced By Start Of First Breeding, Andy Roberts, Jaclyn N. Ketchum, Richard N. Funston Jan 2019

Developmental And Reproductive Characteristics Of Beef Heifers Classified By Number Of Estrous Cycles Experienced By Start Of First Breeding, Andy Roberts, Jaclyn N. Ketchum, Richard N. Funston

West Central Research and Extension Center, North Platte

A retrospective analysis was conducted to evaluate the effect of number of estrous cycles exhibited before breeding on growth and reproductive performance of replacement beef heifers fed ad-libitum or restricted by 20% less than ad-libitum during postweaning development over a 9-yr period. Progesterone concentration in blood samples collected at 9- to 11-d intervals were used to assign heifers into groups by number of estrous cycles exhibited before the start of breeding: 0 (nonpubertal; n = 395), 1 (n = 205), 2 (n = 211), 3 (n = 116), or >3 (n = 249). Heifers (P …

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The Reproductive Season Of The Highland Stoneroller, Campostoma Spadiceum, Evidenced By Museum Specimens, C. Renn Tumlison, Henry Robison, Grace Wills Jan 2019

The Reproductive Season Of The Highland Stoneroller, Campostoma Spadiceum, Evidenced By Museum Specimens, C. Renn Tumlison, Henry Robison, Grace Wills

Journal of the Arkansas Academy of Science

The Highland Stoneroller (Campostoma spadiceum) was described as a distinct species in 2010. Since then, the only study specific to this species is a survey of distribution, and nothing is known about reproduction. We examined 134 lots including 315 specimens of C. spadiceum housed in the Henderson State University collection of fishes to evaluate the timing of reproductive events. We dissected individuals to reveal sex and reproductive status. Females as small as 49 mm total length were able to yolk eggs, and follicles were in development by October. Ripe eggs were present in specimens collected from January through …

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Temperature And Polyunsaturated Fatty Acid’S Effect On Daphnia Magna Reproduction, Mark Albright Dec 2018

Temperature And Polyunsaturated Fatty Acid’S Effect On Daphnia Magna Reproduction, Mark Albright

Electronic Theses and Dissertations

Organisms adapt to their environments by adjusting their biochemistry and physiology; such adaptation is limited by resource availability and physiological constraints. The freshwater crustacean Daphnia magna inhabits a wide range of environments and must survive and reproduce within a range of temperatures. One limit to low-temperature adaptation is thought to be the availability of unsaturated fatty acids necessary to maintain proper fluidity of cellular membranes. D. magna maintained at 10 ºC on a diet poor in unsaturated fatty acids have been observed to produce clutches that fail to develop. However, this has not been observed on a diet rich in …

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Aspects Of The Reproductive Biology And Growth Of The Mississippi Silvery Minnow, Hybognathus Nuchalis (Agassiz, 1855) (Teleostei: Cyprinidae) From The Pearl River, Louisiana., Arely Ramírez-García, Kyle R. Piller Nov 2018

Aspects Of The Reproductive Biology And Growth Of The Mississippi Silvery Minnow, Hybognathus Nuchalis (Agassiz, 1855) (Teleostei: Cyprinidae) From The Pearl River, Louisiana., Arely Ramírez-García, Kyle R. Piller

Southeastern Fishes Council Proceedings

The reproductive biology and growth of the Mississippi Silvery Minnow, Hybognathus nuchalis, is described from multiple sites in the Pearl River, Louisiana. Individuals were collected from August 2011 to August 2012. Ovarian weights, expressed as a percentage of body weights, peaked in December. Size structure ranged from 29.0 to 60.0 mm SL for females and 25.0 to 56.0 mm SL for males. Mature ova were found from November to January. Females reached first maturity (L50) at 37.0 mm SL and L50 for males is at 41.0 mm SL. Sex ratio (females:males) is biased towards females (X2= 18.57 p …

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Bats Of Saint Lucia, Lesser Antilles, Scott C. Pedersen, Gary G. Kwiecinski, Hugh H. Genoways, Roxanne J. Larsen, Peter A. Larsen, Carleton J. Phillips, Robert J. Baker Nov 2018

Bats Of Saint Lucia, Lesser Antilles, Scott C. Pedersen, Gary G. Kwiecinski, Hugh H. Genoways, Roxanne J. Larsen, Peter A. Larsen, Carleton J. Phillips, Robert J. Baker

University of Nebraska State Museum: Mammalogy Papers

Eight species of bat have been previously recorded from the island of Saint Lucia: Noctilio leporinus, Monophyllus plethodon, Artibeus jamaicensis, Brachyphylla cavernarum, Ardops nichollsi, Sturnira paulsoni, Molossus molossus, and Tadarida brasiliensis. Herein, we add a ninth species to the fauna—Pteronotus davyi. These nine species represent nine genera from four families: Noctilionidae, Mormoopidae, Phyllostomidae, and Molossidae. This fauna includes four trophic guilds: N. leporinus (piscivore/insectivore), M. plethodon (nectarivore/pollenivore), A. jamaicensis × schwartzi, B. cavernarum, A. nichollsi, and S. paulsoni (frugivores), and P. davyi, M. molossus, and …

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Bats Of St. Vincent, Lesser Antilles, Gary G. Kwiecinski, Scott C. Pedersen, Hugh H. Genoways, Peter A. Larsen, Roxanne J. Larsen, Justin D. Hoffman, Fitzroy Springer, Carleton J. Phillips, Robert J. Baker Oct 2018

Bats Of St. Vincent, Lesser Antilles, Gary G. Kwiecinski, Scott C. Pedersen, Hugh H. Genoways, Peter A. Larsen, Roxanne J. Larsen, Justin D. Hoffman, Fitzroy Springer, Carleton J. Phillips, Robert J. Baker

University of Nebraska State Museum: Mammalogy Papers

The chiropteran fauna of the island of Saint Vincent, represented by 12 species, is among the most complex in the Lesser Antilles, being represented by four families including Noctilionidae (1 species), Mormoopidae (1), Phyllostomidae (8), and Molossidae (2). This fauna includes four trophic guilds as represented by Noctilio leporinus (piscivore/insectivore); Glossophaga longirostris and Monophyllus plethodon (nectarivore/pollenivore); Artibeus lituratus, A. schwartzi, Brachyphylla cavernarum, Ardops nichollsi, and Sturnira paulsoni (frugivore); and Pteronotus fuscus, Micronycteris buriri, Molossus molossus, and Tadarida brasiliensis (insectivore). One species—Micronycteris buriri—and two subspecies—Sturnira paulsoni paulsoni and Ardops nichollsi vincentensis …

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Predators Modify The Temperature Dependence Of Life-History Trade-Offs, Thomas M. Luhring, Janna M. Vavra, Clayton E. Cressler, John Delong Jun 2018

Predators Modify The Temperature Dependence Of Life-History Trade-Offs, Thomas M. Luhring, Janna M. Vavra, Clayton E. Cressler, John Delong

School of Biological Sciences: Faculty Publications

Although life histories are shaped by temperature and predation, their joint influence on the interdependence of life-history traits is poorly understood. Shifts in one life-history trait often necessitate shifts in another—structured in some cases by trade-offs— leading to differing life-history strategies among environments. The offspring size–number trade-off connects three traits whereby a constant reproductive allocation (R) constrains how the number (O) and size (S) of offspring change. Increasing temperature and size-independent predation decrease size at and time to reproduction which can lower R through reduced time for resource accrual or size-constrained fecundity. We investigated how O, S, and R in …

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Cyanobacteria Reduce Quagga Mussel (Dreissena Rostriformis Bugensis) Spawning And Fertilization Success, Anna G. Boegehold, Nicholas S. Johnson, Jeffrey L. Ram, Donna R. Kashian May 2018

Cyanobacteria Reduce Quagga Mussel (Dreissena Rostriformis Bugensis) Spawning And Fertilization Success, Anna G. Boegehold, Nicholas S. Johnson, Jeffrey L. Ram, Donna R. Kashian

Environmental Science and Geology Faculty Research Publications

Quagga mussels (Dreissena rostriformis bugensis) are highly fecund broadcast spawners invasive to freshwaters of North America and western Europe. We hypothesized that environmental cues from phytoplankton can trigger gamete release in quagga mussels. Nutritious algae may stimulate dreissenid spawning, but less palatable food, such as bloom-forming cyanobacteria, could be a hindrance. The objective of our study was to test whether exposure to cyanobacteria can inhibit quagga mussel spawning and fertilization. We assessed spawning in the presence of serotonin, a known spawning inducer, where adult quagga mussels placed in individual vials were exposed to 13 cyanobacteria cultures and purified algal toxin …

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Life-History Characteristics And Fishery Dynamics Of Red Drum (Sciaenops Ocellatus), In The North-Central Gulf Of Mexico, Corbin Bennetts May 2018

Life-History Characteristics And Fishery Dynamics Of Red Drum (Sciaenops Ocellatus), In The North-Central Gulf Of Mexico, Corbin Bennetts

Master's Theses

Red Drum (Sciaenops ocellatus) are highly targeted recreationally in the Gulf of Mexico, and support a small commercial fishery in Mississippi. Despite their popularity, the stock is assessed using data limited approaches that necessitate accurate life history information. I estimated the year-specific and year-aggregated escapement rates for the Mississippi stock (years 2004 to 2015), which were sensitive to mortality estimation methods; year-aggregated estimates were 6.9 to 28.2 % depending on the method, but temporal patterns were consistent. I then addressed concerns with previously estimated life-history characteristics by describing the sex-specific growth and reproductive dynamics. The three-parameter von Bertalanffy …

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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 …

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Multiple Mating By Females In The Chesapeake Bay Blue Crab Callinectes Sapidus Population, S. Wells, J. Mcconaugha, L. Horth Feb 2017

Multiple Mating By Females In The Chesapeake Bay Blue Crab Callinectes Sapidus Population, S. Wells, J. Mcconaugha, L. Horth

OES Faculty Publications

Mature females of the Chesapeake Bay (USA) blue crab Callinectes sapidus population mate multiple times. Microsatellite DNA analysis of sperm stored in the spermathecae has shown that virtually all (~97%, 104 out of 107) females collected in a 2009−2010 study mated with at least 2 males. Enumeration of stored sperm revealed that despite multiple mating, some females did not have enough sperm to fulfill their lifetime reproductive potential, suggesting that female blue crabs may experience varying levels of sperm limitation. This could result from multiple factors. The average body size of males in the population has decreased, which reduces the …

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Determining The Reproductive Patterns Of The Titan Acorn Barnacle (Megabalanus Coccopoma) In Its Introduced Range, Isabel L. Moran Ms. Jan 2017

Determining The Reproductive Patterns Of The Titan Acorn Barnacle (Megabalanus Coccopoma) In Its Introduced Range, Isabel L. Moran Ms.

Honors College Theses

Invasive species are a significant conservation concern given their contribution to native species decline. The barnacle, Megabalanus coccopoma, is a common invasive species in tropical and subtropical regions of both the Pacific and Atlantic oceans. Little is known about the life history and ecology of M. coccopoma, and data on reproductive biology could provide valuable insight into its propensity to establish introduced populations. Most species of barnacle (including M. coccopoma) are hermaphroditic, but self-fertilization is rare in species studied to date. A recent genetic study of introduced M. coccopoma populations in the southeastern US showed high levels of …

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Glucocorticoids And Parental Effort In Tree Swallows (Tachycineta Bicolor), Mackenzie Prichard Jan 2017

Glucocorticoids And Parental Effort In Tree Swallows (Tachycineta Bicolor), Mackenzie Prichard

Undergraduate Theses, Professional Papers, and Capstone Artifacts

All vertebrates respond to stressful situations through the release of hormones called glucocorticoids (CORT). These hormones alter processes within the body to prioritize long term survival over immediate reproduction. It is hypothesized that this is helps individuals survive until conditions become more favorable for successful reproduction. Historically, stress was hypothesized to primarily to pull organisms out of reproductive life history stages when unfavorable conditions made offspring survival slim (otherwise known as the “CORT-tradeoff hypothesis”). However, recent evidence suggests that birds actively feeding nestlings show elevated CORT levels, possibly due to the increased metabolic demands of parenthood. This relationship has been …

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Reproductive Characteristics Of Landlocked Fall Chinook Salmon From Lake Oahe, South Dakota, Kelsen L. Young, Michael E. Barnes, Jeremy L. Kientz Dec 2016

Reproductive Characteristics Of Landlocked Fall Chinook Salmon From Lake Oahe, South Dakota, Kelsen L. Young, Michael E. Barnes, Jeremy L. Kientz

The Prairie Naturalist

Lake Oahe, South Dakota, USA, landlocked fall Chinook salmon (Oncorhynchus tshawytscha) reproductive characteristics were examined over a 27 year period, from 1988 to 2015. Mean total lengths of spawning females ranged from 665 mm (1995) to 812 mm (2015) with considerable year-to-year variation. Post-spawn female weights varied, ranging from 2.02 kg (2000) to 5.55 kg (2015), with an overall mean of 3.04 kg. Fecundity peaked at 4,555 eggs per female in 2003, which was just 3 years after a low of 2,011 eggs per female in 2000. Relative fecundity based on female weight was greatest at 1,211 eggs/kg …

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Estimating The Frequency Of Sexual Reproduction In The Diatom Stephanodiscus Niagarae, Ann W. Dickens May 2016

Estimating The Frequency Of Sexual Reproduction In The Diatom Stephanodiscus Niagarae, Ann W. Dickens

Biological Sciences Undergraduate Honors Theses

Diatoms are single-celled micro-algae with cell walls composed of silica, that reproduce in a way that results in a decrease in cell size after each round of mitotic (asexual) division. A cell cannot continue to shrink indefinitely, so when the average size of the population reaches a critical threshold, diatoms reproduce sexually and restore their maximal size. It is unclear, however, how frequently diatoms undergo sexual reproduction in nature. As a proxy for sexual reproduction, I monitored changes in cell size of a population of the diatom Stephanodiscus niagarae from the plankton community of Lake Fayetteville (Arkansas, USA). Weekly sampling …

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Consequences Of Developmental Lead (Pb2+) Exposure On Reproductive Strategies In Drosophila, Elizabeth Kathleen Peterson Jan 2016

Consequences Of Developmental Lead (Pb2+) Exposure On Reproductive Strategies In Drosophila, Elizabeth Kathleen Peterson

Legacy Theses & Dissertations (2009 - 2024)

Anthropogenic lead (Pb) pollution is ubiquitous in the environment and a risk factor for both human and wildlife health. Pb exposure has the potential to alter reproductive strategies with respect to mate choice and reproductive output. This could be especially deleterious if these changes disrupt adaptive behavioral and reproductive life history strategies. Therefore, the overall aim of this body of work was to examine the consequences of developmental Pb exposure on reproductive strategies, using Drosophila melanogaster as a model system. In all experiments, D. melanogaster were reared from egg stage to adulthood in either control or leaded medium and were …

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