Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 24 for “"age-at-maturity"”.
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Evolutionary Relationship between Life History and Brain Growth in Anthropoid Primates
… several evolutionary biologists have theorized that the tempo of a species' life history is set by external factors. These factors, such as food availability and predation pressure, determine mortality rates. In turn, mortality rate determines the age at maturity. High mortality rate results in …
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On the reproductive biology of the western Atlantic bluefin tuna, Thunnus thynnus
<p>The Atlantic bluefin tuna, Thunnus thynnus, is a highly migratory species capable of traversing great distances throughout the North Atlantic Ocean, but spawning is known to occur only in the Mediterranean Sea and the Gulf of Mexico/Straits of Florida. The regulatory body charged with managing …
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Growth, Diet, and Reproduction of the Red-Eared Slider (Trachemys Scripta) Inhabiting a Reservoir Receiving a Cold Effluent
… Trachemys scripta, were collected from two habitats at Lake Taneycomo from April 1992 to July 1993. One site was a hypothermic cove near Rockaway Beach, Missouri, and the second site was a normothermic cove in a tributary of Lake Taneycomo known as Bull Creek. The diets of adult sliders were …
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Aging Validation, Growth, and Comparison of Four Age Estimators of the River Redhorse (Moxostoma Carinatum)
Four possible age estimators of river redhorse, otoliths, opercles, scales, and fin rays, were compared for accuracy, precision, and reliability. Validation of annulus formation, using marginal increment analysis, indicated that opercles and otoliths form an annulus from late May to late June. …
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Age, Growth, and Population Structure of Black Redhorse (Moxostoma Duquesnei) and Golden Redhorse (Moxostoma Erythrurum) in Southwest Missouri
Otoliths (lapilli) were used to age black redhorse (Moxostoma duquesnei) and golden redhorse (Moxostoma erythrurum) from three White River tributaries (James River, Bull Creek, and Swan Creek) and one Arkansas River tributary (Elk River) in southwest Missouri. Validation of annulus formation in …
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Inference of ecology from the ontogeny of microfossils
… ecologically to determine whether differences in age at maturity are correlated with heterochrony as expected; accelerated maturity should yield generalized morphology and small size, while delayed maturity should produce specialized morphology and large size. Two of the four species show the …
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Living on the Edge: Conservation of Fish Species at Risk in Canada
… Some of these species are classified as species at risk and afforded legal protection in Canada, yet the decision to protect these populations at the edge of their range is controversial. To determine if edge populations are more likely to be listed as at risk, fish species were grouped based on …
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Updated life history and population structure assessment of spiny dogfish, Squalus acanthias, in the Gulf of Maine
… most abundant shark species in the Western North Atlantic, but recently there was a decline in biomass estimates following a nearly ten-fold increase in fishery landings. Because fishing pressure has been shown to affect population dynamics in targeted species, an update of previous life history …
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Defining rarity and determining the mechanisms of rarity for North American freshwater fishes
… protecting biodiversity depends on sound information on the nature of rarity. Rarity is multidimensional, presenting the need for a quantitative classification scheme by which to label species as rare or common. I defined rarity for freshwater fishes based on the range extents, habitat breadths, …
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Building an In-vitro Cell Model to Study Cellular Basis of Maturation Timing: A Proof of 3D Cell Culture Methodology in Atlantic Salmon Adipose Tissue
… cultures have been shown to represent tissue formations and functions more accurately than two-dimensional (2D) cultures and have been successfully utilized more accurately in model organisms, e.g., to understand cellular modular functions. However, the applications in non-model organisms are …
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Behavioural Ecology of Lake Trout: From Movement Ecology to Bioenergetics
The movement patterns of most organisms are directed to maximizing the success of habitat exploitation, which can be quantified by examining population-level parameters such as size and age at maturity, and the population bioenergetics. Similarly, the behavioural decisions of organisms are …
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Analysis of Cisco (Coregonus artedi) Populations in Eastern Lake Ontario
The Cisco (Coregonus artedi) is a cold-water planktivorous fish species that has undergone significant declines within Lake Ontario as a result of over-exploitation and other anthropogenic impacts. The goal of this project was to expand upon the current scientific knowledge base for Cisco within …
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Geographic variation in size at age of the coral reef fish, Thalassoma lunare (family: Labridae) : a contribution to life history theory.
Key life history traits such as age at maturity, longevity and mortality have all shown correlations with body size. However, the relationship between age and size is particularly important as growth rates (size per time) can have a profound influence on reproductive capabilities and survival. This …
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The Implications of the Target-Area Hypothesis on the Population Dynamics of the Spotted Spiny Lobster, <i>Panulirus guttatus</i>
… on the theory of island biogeography, predicts that larger islands are more effective at intercepting passive immigrants. Most marine invertebrates have meroplanktonic larvae and open population dynamics, so immigration to populations in isolated benthic habitats is primarily by pelagic larval …
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A genetic analysis of reproduction in growth selected lines of chickens
… and physiological aspects of egg production patterns and their relationships with growth parameters were studied utilizing S₁₅, S₁₆(R₃) and S₁₇(R₄) generation pullets from lines selected for high (HW) and low (LW) 8-week body weight. HW pullets laid significantly more defective eggs than LW …
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Characterizing early growth and reproduction of Blueline Tilefish (<i>Caulolatilus microps</i>) to inform stock assessments
Blueline Tilefish is a deepwater species that is found along the United States Atlantic coast and in the Gulf of Mexico. Fisheries for the species have developed in the past five decades, and large increases in landings from the mid-2000s to 2010s have raised management interest. During the most …
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Spatial and Temporal Variation in Lake Huron Yellow Perch (Perca flavescens) Life History Traits
Knowledge of fish population structure allows fisheries managers to account for potentially different responses of discrete groups to external stressors. Life history traits are very useful indicators of population structure because they provide information about fish populations that incorporates …
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Population dynamics of Daphnia galeatat in the biomanipulated Bautzen Reservoir: life history strategies against food deficiency and predation
The population dynamics and demography of Daphnia galeata was analysed in a five year study in the biomanipulated Bautzen Reservoir. Samples were taken two times a week during the period May-July in the pelagic zone of this highly eutrophic water. Major bottom-up and top-down factors were …
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Standards for epiphyseal union in South African children between the ages of 6 to 24 years using low dose X-ray (lodox)
Skeletal age is a measure of biological maturation and is based on the stages of formation of bones. As age increases, skeletal maturation progresses and the various hard tissue changes which take place are uniquely identifiable and defining to each stage of development. Age assessment using …
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