Comparative and Evolutionary Physiology Commons^™

The Relationship Between 11-Ketotestosterone, Cortisol, And Testosterone And Condition Index For Poecilia Reticulata, Shelly Gupta, Brandy G. Kalbach

Biological Sciences

The guppy, Poecilia reticulata, is a common study organism for behavioral and other ecological experiments (Houde, 1997).  As far as we know, no previous data have been compiled regarding hormones and condition index of guppies.  In this experiment we examined the relationship between circulating levels of three hormones (testosterone, 11-ketotestosterone and cortisol) and condition index in males and also made comparisons among the hormone levels, for three guppy sites from the northern range of Trinidad – Aripo River, Marianne River and Small Crayfish River.  Hormone samples were obtained using non-invasive water borne techniques and quantified by our collaborator.  The condition …

The Relationship Between Plasma Steroid Hormone Concentrations And The Reproductive Cycle Of The Northern Pacific Rattlesnake, Crotalus Oreganus, Craig Michael Lind

Master's Theses

To gain a better understanding of the role of steroid hormones in vertebrate reproduction, we quantified steroid hormone concentrations in a free ranging population of the Northern Pacific rattlesnake, Crotalus oreganus. Plasma steroid hormone concentrations were quantified for both male and female snakes throughout the active season (Mar-Oct). We measured testosterone (T), 5α-dihydrotestosterone (DHT), and corticosterone (B) concentrations in male and female snakes. 17β-estradiol (E2) and progesterone (P) were measured in females only. We also observed breeding behaviors (e.g. consortship, courtship, and copulation) in the field and measured testis and follicle size in male and female snakes from museum collections. …

Spots Of Adult Male Red-Spotted Newts Are Redder And Brighter Than In Females: Evidence For A Role In Mate Selection?, Andrew K. Davis, Kristine L. Grayson

Biology Faculty Publications

As aquatic adults, eastern red-spotted newts (Notophthalmus v. viridescens) are generally green with two rows of dorsal spots, which vary in number between individuals and range in colour from orange to red. The function of these spots is unknown, but it is possible that they serve as sexual ornamentations and we examined this hypothesis by testing for sexual dimorphism in spot characteristics. We used an image analysis approach that has been used previously with this and other amphibian species to compare the number, size and colour – redness (hue score) and brightness – of spots in 100 male …

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 …

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 …

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.