Comparative and Evolutionary Physiology Commons^™

Hatching Asynchrony, Survival, And The Fitness Of Alternative Adult Morphs In Ambystoma Talpoideum, Travis J. Ryan

Scholarship and Professional Work - LAS

The mole salamander, Ambystoma talpoideum, exhibits both aquatic (gilled) and terrestrial (metamorphosed) adult morphologies. Previous studies have shown the existence of body-size advantages associated with the terrestrial morph in A. talpoideum and other polymorphic salamanders (e.g., A. tigrinum). However, aquatic adult A. talpoideum mature at a younger age and often breed earlier than terrestrial adults. We tested the hypothesis that early maturation and reproduction in aquatic adults increase fitness (irrespective of body size). We reared larval A. talpoideum in mesocosms and varied the timing of hatching, with early-hatching larvae representing the offspring from early-breeding aquatic adults, and late-hatching larvae representing …

Thermoregulation In Swimming Mallard Ducklings (Anas Platyrhynchos), Aaron James Lynott

All-Inclusive List of Electronic Theses and Dissertations

Temperature regulation in birds has been studied for several decades. However, most studies have been limited to the thermal effects of air. This is surprising considering the abundance of waterfowl and the significant amount of time that many birds spend immersed in water. While we do know that water has a thermal conductivity that is 23 times that of air, the effect of water temperature on temperature regulation remains unknown. Though the thermal effect of water seemingly has a strong influence on the thermoregulation of birds, neonatal aquatic birds seem particularly susceptible. Many aquatic neonates, such as mallard ducklings, enter …

The Influence Of Environmental Ph And Bicarbonate Concentration On The Excretion Of Nitrogenous Waste Products In Two Species Of Freshwater Teleost, Paul D. Fabsits

Masters Theses

The catabolism of amino acids derived from dietary protein results in the production of ammonia and bicarbonate ion, waste products that an animal must eliminate. Often, animals excrete a nitrogenous waste product that is correlated with water availability: Freshwater fish, living where water is abundant, usually excrete ammonia while terrestrial animals excrete urea or uric acid. Recent studies report that fish inhabiting alkaline waters (pH 10) characterized by high bicarbonate concentrations do not excrete ammonia, instead synthesize urea, an energetically expensive process. The conversion to urea excretion by a normally ammonotelic animal is likely to be stimulated by a specific …

Histomorphometric Analysis Of Primate Periodontal Tissues Following Corticotomy In Orthodontics, Wuiteng Koh

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study was to evaluate the prevalence of specific cell types and structures at the active tooth movement site in corticotomized and non-corticotomized specimens obtained from a previous study, and to consider the hypothesis that corticotomy facilitated orthodontics is efficacious due to an inflammatory response rather than tooth-bone block movement. Specimens from 3 monkeys, each of which had a treatment and control quadrant in each arch, were sectioned, mounted on glass slides, and stained with Giemsa, haematoxylin, and Safranin stains. A histomorphometric analysis was performed with DataVoice™, a voice activated computer system which allowed for digitization of …

Morphological Variation In The Southeastern Pocket Gopher, Geomys Pinetis (Mammalia: Rodentia), Stephen L. Williams, Hugh H. Genoways

University of Nebraska State Museum: Mammalogy Papers

The nominal species of southeastern pocket gophers (Geomys pinetis, G. colonus, G. cumberlandius, and G. fontanelus), which collectively occupy a geographic range on the Atlantic and Gulf coastal plain of Alabama, Georgia, and Florida, were examined for morphological variation. Univariate and multivariate analyses were used to determine age, sexual, individual, and geographic variation in G. pinetis. Significant differences were found among different age classes and between sexes. Males displayed higher individual variation than females and external measurements were more variable than cranial measurements. Of the four named species in the pinetis-species group (colonus …

A Light And Electron Microscopic Study Of Visual Neurons In The Medulla Externa Of The Crab Hemigrapsus Nudus, Yu Cheng Liao

Loma Linda University Electronic Theses, Dissertations & Projects

The decapod crustacean with a relatively well-defined visual system have contributed significantly to our understanding of visual neuron morphology and physiology. The general morphology of the optic lobes of several decapods were initially described by Parker (1897) and Hanstrom (1924). In the past few years, several light and electron microscope studies have been made on the lamina ganglionaris: the first optic ganglion, of the lobster (Hamori and Horridge, 1966a); the crayfish (Hafner, 1974; Nassel, 1976a), and the crab (Stowe et al., 1977; Rafuse et al., in preparation). As yet, no adequate description has been made of the visual neurons in …

The Dynamics Of Root Growth And The Partitioning Of Photosynthates In Cool Desert Shrubs, Osvaldo Alberto Fernandez

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This study addresses the nature of physiological and phenological evolutionary strategies of root growth dynamics and energy allocation followed by Atriplex confertifolia, Ceratoides lanata, and Artemisia tridentata growing in their natural cool desert environment.

Root observation chambers with inclined Plexiglass windows were installed in monospecific desert communities of Atriplex confertifolia, Ceratoides lanata and Artemisia tridentata. Soil temperature and water potential measurements taken immediately adjacent to the observation windows indicated a minimal disturbance was caused by the presence of these chambers. For the three species initiation of root growth was observed before initiation of shoot activity, furthermore, active root growth extended …

Critical Flicker Frequency In A Harp Seal, Pagophilus Groenlandicus (Erxleben, 1777), Charles D. Bernholz

University of Nebraska-Lincoln Libraries: Faculty Publications

Critical flicker frequency (CFF) in a free-swimming harp seal (Pagophilus groenlandicus) was investigated using behavioral techniques. The resulting CFF versus intensity contour indicates a definite rod-cone break, confirming a duplex photoreceptor population whose presence had not been observed in previous morphological reports.

Reproductive Wastage In Sheep In Non-Clover Areas, C. H. Trotman

Journal of the Department of Agriculture, Western Australia, Series 4

A Research Round-up report in the June, 1972, issue of the Journal of Agriculture discussed the reproductive performance of sheep in Western Australia and indicated that more than 20 per cent, of mated ewes fail to lamb.

The report presented the first year's results from sheep grazing clover areas.

This report presents results from the nonclover sections of the investigations

Sturt Pea Hosts Collar Rot Fungus, M D. Marcley

Journal of the Department of Agriculture, Western Australia, Series 4

Evidence that Western Australia's Sturt Pea can be attacked by collar rot fungus suggests a reason for the occurrence of collar rot in places where the fungus should not survive.

At Carnarvon for instance, in spite of the hot, dry conditions, the collar rot fungus has been found on eggplants and Tuart trees.

Mating Weaners Does Not Affect Future Ewe Performance, R J. Suiter, K. P. Croker

Journal of the Department of Agriculture, Western Australia, Series 4

Maiden ewes in Western Australia are usually mated in their second year because of supposed ill-effects of earlier mating on the ewe's future production. Mating at a younger age however, providing there was no reduction in future performance, would provide for an extra lamb drop and thus increase the lifetime output of ewes.

Information from various sources indicated that weaners could be successfully mated providing their bodyweights were satisfactory. This trial was carried out to test the results of mating weaners under Western Australian conditions.

Maintaining Ewe Bodyweight For A Late Mating, T Marshall

Journal of the Department of Agriculture, Western Australia, Series 4

DEPARTMENT OF AGRICULTURE experiments have indicated that the bodyweight of ewes at mating can have a large bearing on lambing performance.

It appears that for every 10 lb. increase in pre-mating bodyweight, an increase of some 3 to 6 per cent, lambs born could be expected, depending on the lambing time.

Broiler Research. 1. Meat Strains For Broiler Production, P Smetana

Journal of the Department of Agriculture, Western Australia, Series 4

A broiler trial to compare the performances of three special meat strains and a group of first cross cockerels was conducted at the Poultry Research Station, Wembley, in 1962.

Although there was little difference in profit there are several factors in favour of the special meat strain birds for broiler production.

The Use Of Different Embryos In Studying The Development Of Man, John C. Bartone

Journal of the Minnesota Academy of Science

The early development of man (embryology) is generally taught with the use of embryos of different animals. Human embryos are seldom used. This is true in the medical, graduate and undergraduate curricula. The primary reason for this utilitarian approach is simply because human embryos are generally not obtainable in numbers sufficient for the wide distribution necessary for all colleges and universities. Another reason is that fairly good substitutes are available to exhibit the early embryological stages of development of man. Some of these substitutes are embryos of the chick, frog and pig.

Famous Sheep Breeds. 2. The Corriedale, J A. Mallett

Journal of the Department of Agriculture, Western Australia, Series 4

THE Corriedale sheep is a breed which has achieved widespread popularity throughout the world as a dual-purpose animal.

It was evolved by New Zealand breeders who—not fully satisfied with the performance of either the Merino or the British longwool sheep under their conditions—sought an animal which would combine the superlative wool-producing properties, and outstanding foraging ability of the Merino with the better meat production and better mothering qualities of the British sheep.