Long-term population trends of colonial wading birds (Ciconiiformes) in Louisiana, Florida, Texas, and California were examined using data from Audubon Christmas Bird Counts (1949-1988) and Breeding Bird Surveys (1966-1989). Winter populations of most Louisiana wading birds increased over the 40-year period, with the sharpest increases occurring during the last 20 years. Increased acreage of crayfish (Procambarus) aquaculture in Louisiana appears to be the most significant factor explaining the observed population increases. First, populations of wading-bird species that use crayfish were correlated positively with the wild crayfish harvest, and more strongly with crayfish pond acreage. Second, the regularity of pond management provided a more predictable foraging habitat than did comparable natural areas. Third, the use of crayfish ponds by wading birds peaked during pond drawdowns, which may have increased reproductive success by concentrating prey available to wading birds during their nesting season. Fourth, wading bird species that specialized on crayfish showed the greatest population increases and the strongest correlation with crayfish pond acreage A field study comparing crayfish farms with natural habitats found significant differences in prey availability, and in the relative foraging success of Great Egrets, Snowy Egrets, and White Ibises. Wading birds on crayfish farms took significantly more prey for less effort, and selected more preferred prey. Wild sites had more fish $(P<0.001),$ more total prey $(P<0.001),$ and higher prey densities $(P<0.001)$ than flooded farm ponds. Farm ponds during drawdown, however, had higher densities of fish, more crayfish $(P<0.001),$ and higher prey densities than wild sites $(P<0.001).$ When foraging on crayfish farms, Great Egrets took more total prey $(P<0.05),$ Snowy Egrets took more fish $(P<0.05),$ and White Ibises took more crayfish $(P<0.01)$ than in the wild. Juvenile White Ibis foraged significantly more successfully on crayfish farms than did adult birds on farms or in the wild. Crayfish farms thus provide superior foraging habitats for wading birds during the nesting season. Recent increases in crayfish farm acreage in Louisiana appear to be a major factor causing the long-term population increases of Louisiana's colonial wading birds. These findings have important implications for the conservation and management of Louisiana's wading bird populations / acase@tulane.edu

Crustaceans, like many other invertebrates and some vertebrates, are capable of altering their color by altering the degree of pigment concentration or dispersion in specialized integumental cells known as chromatophores. Pigment translocation in the fiddler crab, Uca pugilator, is regulated by hormones released from the animal's eyestalk neuroendocrine gland, the X-organ-sinus gland complex. This complex contains no fewer than four pigment effector hormones. The release of these hormones is thought to be regulated by neurons impinging directly on the secretory cells, or on cells somewhere along the chain of neurons leading to the X-organ-sinus gland (Fingerman, 1985) Biogenic amines, including dopamine, octopamine, 5-hydroxytryptamine, and norepinephrine, have been shown to have hormone-releasing effects when injected into U. pugilator. Whether or not endogenous stores of these compounds act as neurotransmitters, however, has not been fully illustrated In the following work, I have documented the presence of dopamine, octopamine, norepinephrine and 5-hydroxytryptamine in various tissues of U. pugilator. In addition, I have provided evidence for a mechanism of synthesis of one (5-hydroxytryptamine) using pharmacological blockers against enzymes involved in its synthesis. I have also demonstrated a mechanism whereby the action of one (norepinephrine) is terminated by re-uptake and metabolism of this putitive neurotransmitter. In the final chapter, the relationship of biogenic amines and eyestalk neuropeptides, was examined / acase@tulane.edu

In the Entoniscinae, five new genera are diagnosed, nine new species are described and two species, Paguritherium alatum Reinhard, 1945 and Synalpheion giardi Coutiere, 1908, are redescribed. The first record of an entoniscid from a stenopodid shrimp is reported. Also, the first records of entoniscids from two caridean shrimp families, the Hippolytidea and Palaemonidae, are reported. A new subfamily is proposed for the monotypic Diogenion Codreanu, Codreanu and Pike, 1960. A key to the genera of the Entoniscidae is presented as is a list of species of the Entoniscidae by host species. ftn*Originally published in DAI Vol. 51, no. 11. Reprinted here with corrected bibliographic information / acase@tulane.edu

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Social interactions of twenty-four adult female rhesus monkeys (Macaca mulatta) were examined in groups containing one, two and three adult males from August 1995 to June 1996. Hypotheses were: (1) Social rank will influence female access to mates: Higher-ranking females would have priority of access to mates. (2) Adult sex ratio will influence female interactions with adult males and females: In groups with fewer males per female, female access to mates will depend on dominance rank. In groups with more males per female, female access to mates will depend on active competition: All females will initiate more frequent affiliative and sexual interactions toward males, and exchange more frequent agonistic behaviors with other females. (3) Difference in female access to males in the three groups will disappear after the breeding season The four highest and the four lowest ranking females in each group were chosen as focal animals. Affiliative, sexual, and agonistic interactions between focal females and other adults were recorded using focal animal sampling method (Altmann, 1974). Female interactions in the three groups were compared using 2-way ANOVAs for fall, transition period and spring. Changes of female interactions over time were analyzed using three-way ANOVAs with repeated measures Results did not support the hypothesis of female's social rank influencing access to mates but supported the hypothesis that the number of adult males affects female access to mates. Females in multi-male groups significantly initiated more frequent and maintained longer proximity to males during the early breeding season than females in one-male groups. This suggests female-female competition for mate choice in multi-male groups. Results did not support the hypothesis of subsiding differences in female access to mates after the breeding season. Post-conception estrus in one of the multi-male groups, and peaks of conceptions present in multi-male groups, suggest female competition for mates in multi-male groups / acase@tulane.edu

The greenside darter, Etheostoma blennioides (Teleostomi: Percidae), is a wide-ranging polytypic taxon that occurs throughout Eastern North America. A prior morphological study recognized that E. blennioides was comprised of four subspecies, several morphological races, and three zones of morphological intergradation. This dissertation uses complete sequences from the mitochondrial cytochrome b gene to estimate phylogenetic relationships for 28 populations within the complex. The results from this portion of the dissertation suggest that taxonomic rearrangement is needed, as the currently recognized taxa do not conform to distinct evolutionary lineages. The taxa in the E. blennioides occupy distinctive habitats, including large rivers, upland streams, and shorelines of the Great Lakes. Ecological (microhabitat) and morphological (fin size) data were gathered from 19 populations of greenside darters from across the range of the complex. One of the four equally parsimonious phylogenies generated in Chapter II was used to examine the relationship between ecology and morphology in a phylogenetic context. Fin sizes, morphological characters considered most sensitive to environmental conditions in these fishes, were utilized in a phylogenetic comparative analysis (spatial autocorrelation). The results indicated that no significant phylogenetic constraint exists for fins. Results from a canonical correlation analysis indicated that there was a significant relationship between microhabitat and morphological phenotype for females, but not for males. Factors associated with morphological and ecological diversification of the complex are discussed. Finally, a previous study of geographic variation of the E. blennioides complex failed to address differences in body shape. Therefore, modern geometric morphometric techniques were applied to examine differences in body shape across the range of E. blennioides . Based on landmark-based methods of analysis, the results indicate that there are significant differences in body shape among the taxa in the complex. These shape differences further strengthen the conclusion of species recognition for the genetically unique taxa identified in Chapter II / acase@tulane.edu

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This study focuses on the endocrine-disrupting capabilities of paper and pulpmill effluents discharged into Elevenmile Creek, FL; specifically effects of effluents on levels of testosterone, 11-ketotestosterone, estradiol in blood, vitellogenin production, gonadosomatic index, and condition coefficients in bluegill sunfish, Lepomis macrochirus. Bluegill were captured monthly for one year from Elevenmile Creek and a reference site---Blackwater River. Standard length and weight were recorded, and blood samples were collected. All hormone and vitellogenin levels were measured by ELISA. The reproductive cycle of bluegill in the southeastern United States in a blackwater system was also determined from reference site data. The livers of formalin fixed specimens archived in Tulane's Museum of Natural History from Elevenmile Creek and from the reference site were immunohistochemically examined in an attempt to detect historical differences in vitellogenin production between fish from the two sites. The alternate hypothesis of this investigation was that female bluegill would exhibit a type of masculinization as seen in female mosquitofish captured from this site, indicating an androgenic effect of this type of contamination. Results of Chapter II show that, when compared to reference females, females from Elevenmile Creek exhibited significantly higher levels of estradiol in Spring 2001 (5.50 ng/ml vs. 2.30 ng/ml), vitellogenin in Winter 2001 (2833.70 mug/ml vs. 187.96 mug/ml). When compared to reference males, males from Elevenmile Creek exhibit higher levels of estradiol in Summer 2001 (5.96 ng/ml vs. 2.27 ng/ml), and vitellogenin in Fall 2600 (1136.20 mug/ml vs. 86.57 mug/ml). There was no evidence of masculinization of females or supermasculinization of males. The added nutrients, food supply, and species differences are all plausible explanations for the increased levels of hormones and vitellogenin in bluegill from Elevenmile Creek The reproductive cycle of bluegill found in Florida in blackwater system, displayed in Chapter II begins in spring (April) and continues through the summer (September). In Chapter III, vitellogenin was detected in formalin fixed livers. Historical evidence also shows that exposure of paper and pulpmill effluents has had no adverse effects on the reproductive physiology of bluegill sunfish in the past / acase@tulane.edu

<p>Biodiversity is generated by the process of speciation. Because biological species are defined as populations that are unable to exchange genes with one another, the study of the evolution of reproductive isolation occupies the center of speciation research. A key to deciphering how reproductive isolation evolves is to understand the genetic changes that underlie these barriers to gene flow. Intrinsic postzygotic barriers, such as hybrid sterility or inviability, are known to impede gene flow and especially lend themselves to genetic analysis because of their ease of study in a laboratory setting. Because hybrid sterility likely evolves before hybrid inviability, it potentially plays an important role in the cessation of gene flow. Yet, while their X-linked counterparts have been precisely localized, we remain ignorant of the numbers of and interactions among dominant autosomal loci that are predicted to contribute to F1 hybrid male sterility. </p><p> To address this conceptual void, I examine the genetic architecture of hybrid male sterility between the allopatric sister species Drosophila persimilis and D. pseudoobscura bogotana. First, using a large-scale backcross analysis, I fine-map autosomal QTL from D. persimilis that confer sterility in male hybrids. This fine-mapping shows that loci contributing to hybrid male sterility reside outside chromosomal rearrangements (i.e., regions of reduced recombination) in this allopatric species pairs. In contrast, these QTL do not contribute to hybrid male sterility in the comparable sympatric hybridizing species D. persimilis and D. pseudoobscura, as predicted by models that suggest that hybridizing species persist because of broad regions of reduced recombination. Next, I use a serial backcross design to introgress these sterility-conferring QTL from D. persimilis into a D. p. bogatana genetic background devoid of other alleles from D. persimilis. This introgression study tested a prediction of the dominance theory proposed to explain Haldane's rule: dominant-acting autosomal loci should interact with recessive-acting X-linked loci to produce sterile hybrid males. Surprisingly, the results demonstrated that the "composite" dominance of the autosomal QTL is more important than the dominance of individual QTL for producing Haldane's rule: epistasis among loci elevated their dominant effects on sterility such that individually-recessive-acting autosomal QTL can contribute to F1 male infertility. Finally, using recombination to generate independent lines bearing only small segments of the identified QTL regions, I examine whether single or multiple loci within these regions contribute to the overall effect of hybrid sterility. While the effect of one QTL depends on epistasis between several loci within that small region, the effect of the other QTL appears to derive from a single genetic factor. These results suggest that estimates of the number of genes that contribute to reproductive isolation are at best, likely too low and, at worst, unattainable with the mapping resolution attainable by standard backcross and introgression approaches.</p><p> This dissertation addresses both evolutionary and genetic hypotheses of intrinsic postzygotic isolation. Hybrid male sterility between D. persimilis and D. p. bogotana clearly involves highly specific and complex interactions between homoospecific loci. The mapping results presented here also lay the foundation for the identification and cloning of multiple autosomal sterility-conferring "speciation genes."</p> / Dissertation