Life Sciences Commons^™

Characterization Of The Early Development And Quality Of Red Snapper (Lutjanus Campechanus) Eggs And Larvae In Aquaculture Conditions, Agnès Bardon Albaret

Dissertations

The quality of red snapper Lutjanus campechanus eggs is highly variable and unpredictable in aquaculture, leading to high mortality during early larval rearing. In this work, the viability of red snapper eggs was investigated from fertilization until larvae expired due to exhaustion of vitellin reserves. The studied spawns were obtained via strip spawning wild-caught (n=17) and captive (n=7) females following hormonal induction. The fertilization rate, the hatch rate, and the duration of survival of unfed larvae post hatch were weakly correlated to each other, revealing occurrence of distinct and independent components of egg quality.

Spawns from captive females were characterized …

Clarification Of The Systematics Of The Haploporoidea (Trematoda) With Descriptions Of New Genera And Species, Michael Jay Andres

Dissertations

The superfamily Haploporoidea Nicoll, 1914 comprises two families, the Atractotrematidae Yamaguti, 1939 and the Haploporidae Nicoll, 1914, and the subfamily Cadenatellinae Gibson et Bray, 1982. All members are parasites of the alimentary tract or gall bladder of marine, estuarine, and freshwater herbivorous fishes. Overstreet and Curran (2005a) provided a review of the Haploporidae and recognized four subfamilies, the Chalcinotrematinae Overstreet et Curran, 2005, Haploporinae Nicoll, 1914, Megasoleninae Manter, 1935, and Waretrematinae Srivastava, 1937. In a series of five publications, Blasco-Costa et al. (2009a-e) revised the Haploporinae and erected a fifth subfamily, the Forticulcitinae Blasco-Costa, Balbuena, Kostadinova, et Olson, 2009. The …

Fungal Contribution To Carbon And Nutrient Cycling In A Subtropical Freshwater Marsh, Rong Su

Dissertations

Despite the well-known occurrence of emergent standing litter in freshwater marshes, very little quantitative data is available concerning the functional role and contribution of fungal decomposers to litter decomposition or their impact on ecosystem scale carbon and nutrient cycling. In the present study, microbial respiration and seasonal biomass and production rates of fungal decomposers associated with standing plant litter were examined to assess the quantitative contribution of fungi to both fine scale litter decay processes and large-scale ecosystem carbon flow pathways in a subtropical Typha domingensis and mixed Cladium jamaicense/Juncus roemarianus freshwater marsh, respectively. In addition, the growth …

The Delivery, Speciation, And Fate Of Trace Elements In St. Louis Bay, Mississippi, Gopal Bera

Dissertations

Estuaries are dynamic regions in which there can be significant modification of the riverine flux of trace elements to the open ocean due to various geochemical, physical, and biological processes. Additionally, estuaries are often subject to anthropogenic inputs of trace elements. The first portion of this study investigated the source, behavior, and sediment interaction of anthropogenic stable cesium (Cs) in St. Louis Bay (SLB), MS. A consistent increase in stable Cs concentration was noticed in sediment cores starting from a period when a titanium dioxide refinery on SLB started operations. Weak correlation between Cs and clay percentage and strong correlations …

Biogeochemistry Of Trace Elements In The Mixing Zone Of The Mississippi And Atchafalaya Rivers And Chemical Distributions As Affected By The Deepwater Horizon Blowout, Dongjoo Joung

Dissertations

Selected trace elements (TEs), dissolved organic carbon, and nutrients were studied in Louisiana Shelf waters including the Mississippi (MR) and Atchafalaya (AR) River plumes during periods of high, intermediate, and low river discharges. Seasonal variations in TEs were observed at low salinity, reflecting seasonal changes in the river water endmembers. Shelf surface water dissolved Mo, Cs, U, Ni, and Cu showed conservative behavior with minor scattering in some high salinity waters. Based on associated mixing experiments, nutrient and chlorophyll distributions, as well as surface-bottom concentration contrasts, the non-conservative behavior of TEs was variously related to colloidal flocculation (Fe, Cr), biological …