Thesis (Ph. D.)--University of Oklahoma, 1977. / Includes bibliographical references (leaves 161-164).

Thesis (Ph. D.)--University of Oklahoma, 1976. / Includes bibliographical references (leaves 51-55).

Thesis (Ph. D.) --University of Oklahoma.

Inaug.-diss. - Göttingen. / Lebenslauf. "Literaturverzeichnis": p. [65]-67.

Inaug.-Diss.--Würzburg.

<p> Frogs exhibit a range of locomotor behaviors, which can be broadly grouped based upon limb movement patterns. Asynchronous behaviors are those that involve alternating limb movements and include crawling, climbing, burrowing, and asynchronous (trot) swimming. Synchronous behaviors are those that involve simultaneous limb movements and include jumping, lunge feeding, and synchronous (frog-kick) swimming. The degree of handedness (preferential limb use) in motor responses is thought to reflect functional lateralization of the brain, an indicator of neural complexity. Handedness has been examined across a range of anuran taxa and has been hypothesized to be related to a species&rsquo; preferred locomotor mode, with greater handedness predicted in species that make more extensive use of asynchronous locomotion. In contrast, it has been hypothesized that anuran handedness varies phylogenetically, with ambidexterity being the ancestral condition and handedness being derived. To date, research in this area has focused primarily on derived taxa and relatively little is known about basal taxa. The basal-most anuran family Leiopelmatidae is the sister group to all other frogs (Lalagobatrachia), and represents an excellent test of these competing hypotheses. Moreover, leiopelmatids rely exclusively on asynchronous swimming and likely exceed all other anuran taxa in their reliance on alternating limb movements during locomotion. We tested these competing hypotheses by examining handedness in two behaviors, righting response and trot-swimming, in the leiopelmatid Rocky Mountain Tailed Frog, <i> Ascaphus montanus</i>. Tailed Frogs showed no evidence of handedness despite the prevalence of asynchronous locomotion in their behavioral repertoire. The absence of handedness in a highly asynchronous basal anuran taxon, suggests that this phenomenon was not characteristic of the earliest frogs, but rather appeared later in the evolutionary history of the group. </p><p>

[No abstract submitted] / Science, Faculty of / Zoology, Department of / Graduate

Phylogenetic changes arise by modifications of ancestral ontogenies. However, we are restricted to studying outgroups, not ancestors, so the search for ancestral ontogenies depends on appropriate choice of taxa for study. Alosa sapidissima was chosen for detailed embryological analysis because American shad are members of an early lineage within teleosts and may retain more characters common to the ancestor of teleosts than do more derived lineages. An objective of my research is to determine ancestral ontogenies and modifications that led to modern teleostean ontogenies using outgroup comparisons. I collected a developmental series of hatchery-reared shad spanning the period from fertilization to metamorphosis. Using light and scanning electron microscopy I described embryological development of shad and formulated an anatomical staging system based on external and osteological features. New information about the early development of shad includes: (1) the unique radial polarity of the first neuromast organ to develop, (2) possession of an extensive neuromast line on the trunk in embryonic and larval shad, (3) formation of the autogenous hypural 1 in the caudal fin, and (4) development of gill filaments and operculum long after the yolk-sac larval period, almost at metamorphosis. These features have important functional and physiological implications for shad which need further study. From my description of shad and my working knowledge of embryology I chose a series of developmental events likely to be common to all taxa of teleosts and formulated a representative staging system. I made explicit comparisons between my staging system and published descriptions for other actinopterygian fishes. The staging system and comparisons are summarized in an extensive series of tables, which show heterochronic differences among taxa. Examples of heterochronic shifts include: (1) shifts in form and timing of neurulation, (2) shifts in initial organogenesis relative to epiboly, and (3) shifts in hatching relative to jaw formation. Seven characters were used to examine the phylogenetic relationships of neopterygian fishes. Basic objectives of comparative embryology have not changed but methods used for descriptive embryology and our conception of how to make phylogenetic comparisons have changed. Future work should focus not only on excellent modern descriptions of development but also on increasingly sophisticated phylogenetic comparisons.

No description available.

Foraging behaviour is an important component of an animal’s ecology. Increases in energetic costs associated with reproduction, should have marked effects on foraging behaviour, but may be compounded by the effects of environmental factors. I investigated the activity patterns of female M. tricolor over the reproductive period using radio telemetry. Six female bats were radio-tagged during each reproductive period: early pregnancy, late pregnancy and lactation. Times at which bats entered and exited the cave were recorded, as was the temperature, moon-phase, cloud cover, wind speed, rainfall and insect abundance. These data were used to calculate emergence time, number of foraging bouts and foraging duration for each reproductive period, which were then correlated with the environmental variables.