Thesis (M.S.)--Marshall University, 2002. / Title from document title page. Document formatted into pages; contains viii, 140 p. with illustrations. Includes bibliographical references (p. 32-36).

Thesis (Ph. D.)--University of Adelaide, 1986. / Includes bibliographical references.

Thesis (Ph. D.)--Oregon State University, 2001. / Typescript (photocopy). Includes bibliographical references. Also available on the World Wide Web.

Theses (M.S.)--Marshall University, 2007. / Title from document title page. Includes abstract. Document formatted into pages: contains xiv, 113 pages including color illustrations. Includes vitae. Bibliography: p. 97-99.

Thesis (Ph.D.) -- University of Texas at Arlington, 2008.

[From Introduction] For many years the problem of interrelationships within the Arthropoda and, indeed, the origin of the Phylum itself have been of interest to many zoologists. It was felt, for reasons which will be given later, that one of the studies which might throw some light on this matter is that of the neuromuscular physiology of arachnid appendages. Consequently it was proposed that the work which is reported here should be primarily concerned with this problem. As in so many cases involving live animals, both the experimental subjects and the experimenter gradually managed to change the direction in which work was proceeding and the result is that only a preliminary attack has been made on the original problem, while most of the material submitted here deals either with functional anatomy or with biological-cum-behavioural characteristics of the experimental animal. Thus it was found that to develop experimental preparations for neuro-muscular studies, it was necessary to work out the anatomy of the muscles and nerves of the appendages used; but this it is not enough. For these nerves and muscles are part of a functional complex which operates as a unit and have therefore to be studied in relation to the structures that they move. Considerations at this level, in fact, carried the study to the plane of functional anatomy. Furthermore it was recognised that even the comprehension of a limb as a functional complex cannot be acquired in isolation. All structures have an evolutionary history and in any consideration of functional anatomy this history must be taken into account - even if the consideration requires extension to the problem of the origin of the group immediately under study.

Thesis (M.S.)--Tennessee Technological University, 2009. / Title from title page screen (viewed on Feb. 5, 2010). Bibliography: leaves 35-39.

Graduation date: 1994

Coexistence is common in nature. Two fundamental conditions must meet for competitive species to coexist. First, at least one environmental dimension must be heterogeneous enough for various species to exploit it. Second, these species must show a certain degree of intrinsic potential to differentiate along this dimension. Organisms living and partitioning in mosaic habitats are often destined to coexist. Here, I propose that habitat selection is one of the major mechanisms promoting coexistence of desert scorpions. I tested this mechanism in a three-species community (Centruroides exilicauda, Vaejovis spinigerus, and Hadrurus arizonensis) in the Tucson Mountain area. The results show (1) Density-independently selected habitats allowed the scorpions to survive but not to coexist. (2) The dynamic nature of density-dependent habitat selection ensured the scorpions coexistence in various situations. The reckless behavior demonstrated by the subordinate species (i.e. foraging in the face of danger from large species) confirmed this point. (3) Life-history characteristics, especially the body size of the scorpions, play a momentous role in positioning the scorpions on the arena of species interaction. Large scorpions always preempt the best habitats and become the dominant species. And small scorpions have to adjust their habitat preferences in deference to the large. C. exilicauda, the smallest species, is the subordinate. Its habitat use was controlled directly by the density of V. spinigerus and indirectly by the density of H. arizonensis. V. spinigerus, the most abundant species, tolerates many habitats. Its habitat use was molded by the density of H. arizonensis. Being the largest and the dominant species, the habitat use of H. arizonensis depended exclusively on its own density. Thus, the correlation of their selective behavior and density fostered the scorpions' coexistence in an ever changing desert environment.

All the taxa of scorpions previously described from South West Africa are revised and a monographic account presented with phylogenetic and biogeographic discussions and conclusions derived in terms of current concepts in systematic zoology which include cladistics and historical biogeography. South West Africa is treated as a subregion of the Afrotropical region and the limits of this subregion coincide broadly with the political borders. All the characters used are defined and illustrated. Many characters previously unstudied for the fauna are investigated. These include comparative studies of trichobothria distributions and detailed structures of the hemispermatophore. Disc electrophoresis of the haemolymph of a few species was carried out and the results discussed. Ecological factors are extensively described and discussed. The nature of the substratum, taken in its broadest possible definition, was found to be the most important single factor determining species distribution. 70 subgeneric taxa were revised, 45 of which are retained as valid, while 11 new species are described bringing the number of known species to 56. These are distributed among seven genera as follows: Buthotus, two species; Karasbergia, one species; Parabuthus, 14 species; Urop1ectes, 10 species; Hadogenes, three species; Lisposoma, two species; Opisthophthalmus, 24 species. Determination keys are provided for all levels of taxa occurring in South West Africa. / Thesis (Ph.D.)-University of Natal, Pietermaritzburg, 1978.