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Articles 1 - 8 of 8

Full-Text Articles in Life Sciences

Seasonality Of Conceptions Under Varying Conditions In A Rhesus Macaque Breeding Colony, Ryan Disney Patrick Dunk Aug 2013

Seasonality Of Conceptions Under Varying Conditions In A Rhesus Macaque Breeding Colony, Ryan Disney Patrick Dunk

Theses and Dissertations

Rhesus macaques (Macaca mulatta) are well documented as seasonal breeders. Despite this, little is known about what factors influence seasonal reproduction in rhesus. It has been proposed that rhesus are "relaxed income breeders" (Brockman and van Schaik, 2005), which means they respond to changes in photoperiod but endogenous cues can allow deviations from photoperiod-timed seasonality. This study presents the results of a natural experiment on the influence of different housing conditions (featuring different levels of environmental exposure) on the seasonal pattern of reproduction in rhesus. Once the number of attempts was controlled for, rhesus did not exhibit a seasonal distribution ...


Impact Of Self-Fertilization On Fecundity, The Timing Of First Reproduction, And Population Genetic Structure: Is A Mate Worth The Wait?, Serena Caplins Jun 2013

Impact Of Self-Fertilization On Fecundity, The Timing Of First Reproduction, And Population Genetic Structure: Is A Mate Worth The Wait?, Serena Caplins

Theses and Dissertations

Organisms capable of self-fertilization typically exhibit two evolutionary syndromes uniting high inbreeding depression with low levels of selfing, or low inbreeding depression and high levels of selfing. This study tests for inbreeding depression in an apparent self-compatible, hermaphroditic marine nemertean worm, Prosorhochmus americanus. Fecundity and timing to first reproduction were assessed in isolated and paired worms. Isolated worms produced significantly more offspring than paired worms and did not show inbreeding avoidance. The selfing rate of natural populations was evaluated using species-specific microsatellites and is consistent with preferential selfing (mean: 0.801), though some outcrossing appears to take place. Population genetic ...


Effects Of Environmental Variables On The Reproduction Of Quagga Mussels (Dreissena Rostriformis Bugensis) In Lake Mead, Nv/Az, Richard Steven Ianniello May 2013

Effects Of Environmental Variables On The Reproduction Of Quagga Mussels (Dreissena Rostriformis Bugensis) In Lake Mead, Nv/Az, Richard Steven Ianniello

UNLV Theses, Dissertations, Professional Papers, and Capstones

In 2007, quagga mussels (Dreissena rostriformis bugensis) were found in Lake Mead and have spread downstream on the Colorado River and to other lakes and reservoirs in the Southwestern United States. The quagga mussel's extremely quick colonization of Lake Mead and annual veliger abundance trends provide evidence that the quagga mussels in the Southwest have different reproductive behavior than in previous habitats. This study is one of the first to specifically examine quagga mussel reproduction in the Southwest and examines how quagga mussel reproduction varies at sites known to have different temperatures and other environmental variables resulting from the ...


Assessing Multiple Endpoints Of Atrazine Ingestion On Gravid Northern Watersnakes (Nerodia Sipedon) And Their Offspring, Lorin A. Neuman-Lee, Karen F. Gaines, Kyle A. Baumgartner, Jayme R. Voorhees, James M. Novak, Stephen J. Mullin Jan 2013

Assessing Multiple Endpoints Of Atrazine Ingestion On Gravid Northern Watersnakes (Nerodia Sipedon) And Their Offspring, Lorin A. Neuman-Lee, Karen F. Gaines, Kyle A. Baumgartner, Jayme R. Voorhees, James M. Novak, Stephen J. Mullin

Karen F. Gaines

Ecotoxicological studies that focus on a single endpoint might not accurately and completely represent the true ecological effects of a contaminant. Exposure to atrazine, a widely used herbicide, disrupts endocrine function and sexual development in amphibians, but studies involving live-bearing reptiles are lacking. This study tracks several effects of atrazine ingestion from female Northern Watersnakes (Nerodia sipedon) to their offspring exposed in utero. Twenty-five gravid N. sipedon were fed fish dosed with one of the four levels of atrazine (0, 2, 20, or 200 ppb) twice weekly for the entirety of their gestation period. Endpoints for the mothers included blood ...


Greater Sexual Reproduction Contributes To Differences In Demography Of Invasive Plants And Their Noninvasive Relatives, Jean H. Burns, Eleanor A. Pardini, Michele R. Schutzenhofer, Y Anny Chung, Katie J. Seidler, Tiffany M. Knight Jan 2013

Greater Sexual Reproduction Contributes To Differences In Demography Of Invasive Plants And Their Noninvasive Relatives, Jean H. Burns, Eleanor A. Pardini, Michele R. Schutzenhofer, Y Anny Chung, Katie J. Seidler, Tiffany M. Knight

Biology Faculty Publications & Presentations

An understanding of the demographic processes contributing to invasions would improve our mechanistic understanding of the invasion process and improve the efficiency of prevention and control efforts. However, field comparisons of the demography of invasive and noninvasive species have not previously been conducted. We compared the in situ demography of 17 introduced plant species in St. Louis, Missouri, USA, to contrast the demographic patterns of invasive species with their less invasive relatives across a broad sample of angiosperms. Using herbarium records to estimate spread rates, we found higher maximum spread rates in the landscape for species classified a priori as ...


Assessing Multiple Endpoints Of Atrazine Ingestion On Gravid Northern Watersnakes (Nerodia Sipedon) And Their Offspring, Lorin A. Neuman-Lee, Karen F. Gaines, Kyle A. Baumgartner, Jayme R. Voorhees, James M. Novak, Stephen J. Mullin Jan 2013

Assessing Multiple Endpoints Of Atrazine Ingestion On Gravid Northern Watersnakes (Nerodia Sipedon) And Their Offspring, Lorin A. Neuman-Lee, Karen F. Gaines, Kyle A. Baumgartner, Jayme R. Voorhees, James M. Novak, Stephen J. Mullin

Faculty Research & Creative Activity

Ecotoxicological studies that focus on a single endpoint might not accurately and completely represent the true ecological effects of a contaminant. Exposure to atrazine, a widely used herbicide, disrupts endocrine function and sexual development in amphibians, but studies involving live-bearing reptiles are lacking. This study tracks several effects of atrazine ingestion from female Northern Watersnakes (Nerodia sipedon) to their offspring exposed in utero. Twenty-five gravid N. sipedon were fed fish dosed with one of the four levels of atrazine (0, 2, 20, or 200 ppb) twice weekly for the entirety of their gestation period. Endpoints for the mothers included blood ...


A Comprehensive Research Framework For Geographic Parthenogenesis In Whiptail Lizards (Genus Aspidoscelis), Adam Leland Jan 2013

A Comprehensive Research Framework For Geographic Parthenogenesis In Whiptail Lizards (Genus Aspidoscelis), Adam Leland

UNLV Theses, Dissertations, Professional Papers, and Capstones

One of the most compelling topics in biology has been the ubiquity of sexual reproduction in living organisms. Because the ecological and evolutionary advantages of sex are well founded, those organisms that reproduce asexually remain enigmatic. Parthenogenesis, the clonal reproduction of an all-female species without the need for males, is a relatively common form of asexual reproduction in vertebrates, and has been subject of numerous academic investigations. Many parthenogenic organisms also share aspects of their geographic distributions, such as inhabiting higher latitudes, higher altitudes, islands or island-like habitats, xeric environments, and marginal, disturbed or ecotonal habitats relative to their sexual ...


Benzo[A]Pyrene Effects On Fundulus Heteroclitus Reproductive Endpoints, Frank Booc Jan 2013

Benzo[A]Pyrene Effects On Fundulus Heteroclitus Reproductive Endpoints, Frank Booc

Electronic Theses and Dissertations

Benzo[a]pyrene (BaP) is a polycyclic aromatic hydrocarbon (PAH) that modulates aromatase enzyme function and, thus, potentially interrupts normal reproductive function. The aim of this study was to use a fish model, Fundulus heteroclitus, to assess whether BaP exposure adversely impacted reproduction. Adult fish were exposed to waterborne BaP concentrations of (0, 1 or 10 μg/L) for 28 days. Males and females were combined for the second half of the exposure (days 14-28) in order to quantitate egg production and fertilization success. Egg fertilization and subsequent hatching success of F1 embryos was significantly decreased by 10 μg/L ...