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Tolerance, Bioenergetics And Biochemical Composition Of The Blue Crab, Callinectes Sapidus Rathbun, Exposed To The Water-Soluble Fraction Of South Louisiana Crude Oil., Shiao Yu Wang

LSU Historical Dissertations and Theses

The tolerance, bioenergetics, growth, molting frequency and biochemical composition of juvenile blue crabs, Callinectes sapidus, exposed to the water-soluble fraction of South Louisiana crude oil were determined during a 21-d exposure period. Blue crabs were highly tolerant to petroleum hydrocarbons; the LC50 was 3927 ppb on day 21. Rates of energy intake decreased with increasing hydrocarbon concentration. Although energy expenditure rates of crabs exposed to 2504 ppb were not significantly higher than that of control crabs, they were significantly higher than those of crabs exposed to 820 and 1476 ppb. The resulting decrease in scope for growth was thus due …

Anti-Mosquito Behavior Of Adult And Juvenile White-Footed Mice (Peromyscus Leucopus) (Treehole Mosquito, Aedes Triseriatus, Epidemiology), Connie Isaacs

Doctoral Dissertations

Rodents seldom are identified as hosts for mosquitoes, based on serological analysis of bloodmeals. However, due to limited survey and lack of sensitivity in most bloodmeal analyses, host species can be misrepresented or undetected. Knowledge of behavior of a potential host species can complement results of bloodmeal analysis, because active vertebrates may prevent mosquito feeding and thus rarely serve as hosts. The objectives of this study were to characterize anti-mosquito behavior in the white-footed mouse (Peromyscus leucopus noveboracensis) and to examine effectiveness of such behavior in mice based on age, prior exposure to mosquitoes, and immediate environment.

I used wild-stock …

Characterization Of Heat-Shock And Chemical-Stress Induced Changes In The Gene Expression Of Mammalian Lymphocytes, David Ivan Rodenhiser

Digitized Theses

To investigate the effect of heat-shock (HS) on the gene expression of mammalian blood cells, human, mouse and rabbit blood cells were cultured and incubated at elevated temperatures or in the presence of ethanol or sodium arsenite, and the patterns of polypeptides synthesized by these cells analyzed by one- and two-dimensional polyacrylamide gel electrophoresis (PAGE). The in vitro exposure of human lymphocytes or human myeloma cells to short term increases in incubation temperature (41(DEGREES) - 43(DEGREES)C) results in the enhanced synthesis of heat-shock proteins (HSPs) of 110, 100, 90, 70 and 65 kilodaltons, and the depressed synthesis of many polypeptides …

Population Dynamics Of The Monogenea (Platyhelminthes) On The Bluegill, Lepomis Macrochirus, In Southern Louisiana., Leon F. Duobinis-Gray

LSU Historical Dissertations and Theses

Seven species of Monogenea of the subfamily Ancyrocephalinae were collected from 700 Lepomis macrochirus from two eutrophic localities in southern Louisiana. Host specimens were collected monthly from May 1982 through April 1984 from Pat's Bay and Spanish Lake. The relative densities of nonlarval Onchocleidus ferox, Actinocleidus fergusoni, Haplocleidus acer, H. dispar, Anchoradiscus triangularis, Cleidodiscus robustus, and C. nematocirrus were analysed for correlation with water temperature, significant differences in locality, temporal and spatial dynamics, and effect of host sex on population densities. The three more abundant species, O. ferox, A. fergusoni, and H. acer, were warm-water forms, whereas H. dispar and …

Diffusion Via Cell-To-Cell Membrane Channels, Richard Gregory Safranyos

Digitized Theses

Cell-to-cell (or gap junctional) membrane channels allow the direct movement of molecules from the cytoplasm of one cell to the cytoplasm of adjacent cells. While functioning to maintain homeostasis among cells in a tissue, these channels may also function in the transmission of signals involved in pattern formation in development. This thesis investigates the properties of cell-to-cell membrane channels in a developing tissue.;The rates of diffusion for the intercellular movement of fluorescent tracers, expressed as (D(,e)), have been measured among the developing epidermal cells of a larval beetle, Tenebrio molitor L. The spread of injected tracers in this monolayer was …

Factors Governing Patterns Of Brood Defense In Male Smallmouth Bass (Micropterus Dolomieui), Mark Stephen Ridgway

Digitized Theses

I examined the effects of offspring stage, brood size, and parental age on the patterns of brood defense in nesting male smallmouth bass (Micropterus dolomieui), a centrarchid fish with male parental care, in Lake Opeongo, Ontario. Parental defense against conspecific models of equal length ((+OR-)1 cm) was used as a measure of parental commitment to the brood. Based on Williams' principle, or the trade-off between present and future reproduction, parental males should adjust their level of brood defense to reflect the value of current offspring relative to their expected future reproduction.;Parental defense increased as a model intruder approached the nest …

Developmental Regulation Of Protein Synthesis In Hymenolepis Diminuta, Afzal Ahmed Siddiqui

Digitized Theses

Protein synthesis and its regulation was studied for the first time in the rat tapeworm, Hymenolepis diminuta, during strobilization. Parasites were metabolically labelled with ('35)S-methionine and the pattern of gene products synthesized was obtained for the scolex/neck region, male proglottids, female proglottids and onchospheres by high resolution 2-dimensional polyacrylamide gel electrophoresis and fluorography. Gene products unique to different sexually differentiated proglottids were localized to the nuclear, brush border, mitochondrial, microsomal and cytosolic fractions obtained by detergent treatment and osmotic shock, followed by differential centrifugation. The purity of different fractions was monitored by transmission electron microscopy and enzyme marker studies. Total …

The Reproductive Physiology Of Brook Charr (Salvelinus Fontinalis, Mitchill) From Neutral And Acidic Lakes In Northern Ontario, Robert Jean Roy

Digitized Theses

This study tested the hypothesis that the reproductive physiology of brook charr (Salvelinus fontinalis) differed between acidic and neutral lakes. Charr were collected from neutral (pH > 6.5) and acidic (pH < 6.5) lakes in the Sault Ste Marie and Blind River areas of Northern Ontario from June to November of 1981 to 1983. Female brook charr from neutral lakes initiated exogenous vitellogenesis in July. Charr from acidic lakes began exogenous vitellogenesis approximately one month later than neutral lake charr. Charr from acidic lakes had fewer yolky oocytes and more oil droplet oocytes than those from neutral lakes in July and August. However, oocyte development was accelerated from September onwards and the abundance of all oocyte stages was the same in charr from acidic and neutral lakes by October. Charr from the acidic lakes produced significantly more mature ova than charr from neutral lakes, but the average weight and diameter of the ova were decreased. Plasma estrogen and vitellogenin levels did not differ among charr from acidic and neutral lakes. Male brook charr from neutral lakes initiated rapid spermatogenesis in June, as measured by the increase in spermatocyte and spermatozoa cyst diameter and percent of testis area. Charr from acidic lakes initiated rapid spermatogenesis and spermiogenesis in July, one month later than charr from the neutral lakes. The rate of spermatogenesis increased in charr from acidic lakes in September, so by October, the quantity of spermatozoa in their testes was the same as in charr from neutral lakes. Histological evidence indicates that charr from acidic lakes did not spawn in October and November, as did those in neutral lakes. Spawning activity was observed in the neutral lakes by mid-October, but spawning still had not occurred by mid-November in the acidic lakes. This study is the first to demonstrate a change in the reproductive physiology of fish due to pH under natural conditions.