The simultaneous effects of dietary fiber, temperature, and daylength on the gastrointestinal morphology and physiology in meadow voles (Microtus pennsylvanicus) were investigated. Voles were randomly divided (10 in each group) and placed in 15-day treatment regimes [cold (5 C) and warm (21 C), daylengths long (18L:6D) and short (6L:18D), and diets of high fiber (50% neutral detergent fiber [NDF]) and low fiber (5% NDF) content] followed by a 5-day digestibility trial to determine diet digestibility in relation to food intake. Total mass of individuals, length, wet mass and dry mass of the stomach, small intestine, caecum, large intestine, adrenal glands, liver, and kidneys was evaluated. Data was analyzed by ANOVA using the SAS system. Meadow voles increased food intake but decreased turnover time and digestive efficiency under low ambient temperature condition, short daylength, and/or high dietary fiber. Increased energy demand had a minimal effect on the gastrointestinal tissue mass but resulted in slightly increased length of all tissues except the small intestine. The increased food intake and small changes to gastrointestinal morphology during times of increased energy demands suggest that meadow voles are able to meet their energy needs primarily through increased food intake, and therefore more energetically expensive gastrointestinal changes are minimized. / Master of Science

No description available.

The first part of the thesis concerns phylogenetic relationships of eimerian coccidia from arvicoline rodents based on nuclear 18S rRNA, and mitochondrial COI and COIII genes, as well as morphological and morphometrical analyses of the eimerian oocysts. Population-genetic structure of eimerian coccidia was also analyzed and haplotype networks were constructed. The second part of the thesis is based on elucidation of the origin of infections of arvicoline rodents with Isospora spp. using three different approaches - phylogenetic analyses (18S rRNA, COI, and COIII genes), morphological and morphometrical data, and experimental infections. Techniques of field parasitology, laboratory methods of parasitological examination, molecular-genetic diagnostics, phylogeny, and taxonomy were used in the course of both parts of the study.

Graduation date: 1994

Thesis (M.S.)--Florida State University, 2003. / Advisor: Dr. Zuoxin Wang, Florida State University, College of Arts and Sciences, Dept. of Psychology. Title and description from dissertation home page (viewed Oct. 1, 2003). Includes bibliographical references.

No description available.

No description available.

Thesis (Ph. D.)--Florida State University, 2004. / Advisor: Dr. Zuoxin Wang, Florida State University, College of Arts and Sciences, Dept. of Psychology. Title and description from dissertation home page (viewed Jan. 12, 2005). Includes bibliographical references.

Thesis (Ph. D.)--Florida State University, 2004. / Advisor: Dr. Zuoxin Wang, Florida State University, College of Arts and Sciences, Dept. of Psychology. Title and description from dissertation home page (viewed Sept. 22, 2004). Includes bibliographical references.

Cranial and external measurements in 422 museum specimens of the common vole, Microtus arvalis, from Switzerland were examined to determine whether they varied with altitude in accordance with either (1) Bergmann's Rule, or (2) subspeciation. Correlation coefficients between altitude and size were calculated on 32 dimensions, each of which had been divided into sex segregated age groups. In not one of the 108 tests was correlation significant. The lack of adherence to Bergmann's Rule was investigated by (1) reviewing the basic concepts of the Rule, as applied to homeotherms; (2) identifying the major abiotic and biotic selection pressures that might affect growth in Microtus arvalis, including climate and competition with sympatric congenerics; and (3) indicating deficiencies in data derived from museum specimens which might have influenced the computations. There were several references in the literature to the occurrence of two subspecies of Microtus arvalis in Switzerland - the nominate subspecies M. a. arvalis (Pallas, 1779) and a montane subspecies called either M. a. incertus (Selys-Longchamps, 1841) or M. a. rufescentefuscus (Schinz, 1845). The lack of evidence in this study for the existence of two phenotypically and distributionally distinct subspecies was considered by (1) examining the general appropriateness of discussing variation in Microtus arvalis in terms of subspeciation; and (2) reviewing the literature on the diagnostic characters and distribution attributed to the montane morph. Two major conclusions were drawn. The first was that Bergmann's Rule should not be considered a "rule" until firm definitions are established on at least two of its founding precepts - the groups of animals to which it applies and the taxonomic level at which it applies - and until it is found to apply to a majority of the cases for which it is intended. The second conclusion was that for species like Microtus arvalis, in which growth is highly variable and distribution is by and large continuous, the usefulness of formal recognition of in-fraspecific populations is questionable until an overview of the geographic variability of the species as a whole is well documented. / Science, Faculty of / Zoology, Department of / Graduate