Comparative and Evolutionary Physiology Commons^™

Comparing Ionoregulation And Modes Of Nitrogen Excretion Across The Life Cycle Of Parasitic And Non-Parasitic Lamprey Species, Shannon Davidson

Theses and Dissertations (Comprehensive)

Abstract

Ionoregulation and nitrogenous waste (N-waste) metabolism in fishes has been extensively documented in teleosts and elasmobranchs, but less so in lampreys (Petromizontiformes). All lamprey species undergo metamorphosis which drastically changes their physiology and modes of feeding. However, differences in ionoregulatory mechanisms due to anadromous versus non anadromous life history strategies emerge following metamorphosis in different lamprey species. Furthermore, some species, such as anadromous juvenile sea lamprey (Petromyzon marinus), are parasitic and migrate to seawater (SW) to ingest blood protein from host fishes, while juveniles of freshwater (FW), non-parasitic species, such as the American brook lamprey …

Design And Validation Of Artificial Feeders To Study Feeding Preferences And Growth Of Hematophagous Juvenile Sea Lamprey (Petromyzon Marinus), Gracie Li-Ting-Wai

Theses and Dissertations (Comprehensive)

The parasitic and invasive land-locked sea lamprey Petromyzon marinus populations contributed to the collapse of the Great Lakes fisheries in the mid-1900s, while native anadromous populations are currently under threat and require conservation efforts for protection. Despite the increasing concern for both populations of this species, the juvenile stage of the sea lamprey’s life cycle has not been well studied. This is due, in part, to ethical concerns raised around holding live host fish with juveniles and the lack of an alternative feeding method to maintain these juveniles in the laboratory. The feeder should be designed to minimize fouling of …

Physiological Impacts Of Lampricides On Invasive Sea Lamprey (Petromyzon Marinus) And Non-Target Fishes, Razvan, Adrian Ionescu

Theses and Dissertations (Comprehensive)

Parasitic sea lamprey (Petromyzon marinus) ingest large quantities of blood from fishes using their oral disc and rasping tongue, most often killing the host. In the early 1900s, sea lamprey invaded the Laurentian Great Lakes, decimating sport, commercial and culturally significant fisheries. Since the early 1960s, chemical control using the lampricides 3- trifluoromethyl-4-nitrophenol (TFM) and niclosamide have helped to reduce sea lamprey populations by 90%. Lampricides are applied to larval lamprey nursery streams targeting many generations of lamprey at once. However, there is concern about the potential adverse effects of lampricides on other fishes, particularly vulnerable lake sturgeon (Acipenser fulvescens) …

Alternative Nad(P)H Dehydrogenase And Alternative Oxidase: Proposed Physiological Roles In Animals, Allison Mcdonald, Dmytro V. Gospodaryov

Biology Faculty Publications

The electron transport systems in mitochondria of many organisms contain alternative respiratory enzymes distinct from those of the canonical respiratory system depicted in textbooks. Two of these enzymes, the alternative NADH dehydrogenase and the alternative oxidase, were of interest to a limited circle of researchers until they were envisioned as gene therapy tools for mitochondrial disease treatment. Recently, these enzymes were discovered in several animals. Here, we analyse the functioning of alternative NADH dehydrogenases and oxidases in different organisms. We propose that both enzymes ensure bioenergetic and metabolic flexibility during environmental transitions or other conditions which may compromise the operation …

Identification Of The Alternative Oxidase Gene And Its Expression In The Copepod Tigriopus Californicus, Allison Mcdonald, Carly E. Tward, Willie Cygelfarb, Jaspreet Singh

Biology Faculty Publications

In addition to the typical electron transport system (ETS) in animal mitochondria responsible for oxidative phosphorylation, in some species there exists an alternative oxidase (AOX) pathway capable of catalyzing the oxidation of ubiquinol and the reduction of oxygen to water. The discovery of AOX in animals is recent and further investigations into its expression, regulation, and physiological role have been hampered by the lack of a tractable experimental model organism. Our recent DNA database searches using bioinformatics revealed an AOX sequence in several marine copepods including Tigriopus californicus. This species lives in tidepools along the west coast of North …

Molecular Characterization Of The Mummichog (Fundulus Heteroclitus) Ovarian Steroidogenic Pathway And Implications For Exogenous Estrogen Effects During Follicular Development, Thiviya Kanagasabesan

Theses and Dissertations (Comprehensive)

This study investigated ovarian development in Fundulus heteroclitus (mummichog), through molecular characterization of key mediators in the ovarian steroidogenic pathway; these included ovarian StAR (steroidogenic acute regulatory protein), cytochrome P450 enzymes, estrogen receptors (ERα, ERβ1 and ERβ2), and gonadotropin receptors (FSHr and LHr); additionally, hepatic vitellogenin (VTG1) and ERs, and brain P450 aromatase (P450arom; CYP19b) were studied. Fish were staged into cortical alveolus, vitellogenic, early mature, late mature, and ovulating stages of maturation; blood (plasma), ovary (tissue and isolated ovarian follicles per stage), liver, and brains were collected. Testosterone (T), 17β-estradiol (E₂) and maturation inducing steroid (MIS), measured …

Gill Structure & Function In Parasitic And Non-Parasitic Lampreys: The Effects Of Metamorphosis And Freshwater-Seawater Transfer, Julia Sunga

Theses and Dissertations (Comprehensive)

Lamprey (Petromyzontiformes) are a phylogenetically ancient group of jawless fishes that begin their lives as filter-feeding larvae (ammocoetes) before undergoing a complex metamorphosis into juvenile lamprey that involves major changes to their internal and external body plan. Some parasitic species, such as the sea lamprey (Petromyzon marinus), migrate to sea following metamorphosis, where they use their oral discs and rasping tongue to attach to and ingest vast quantities of blood from fishes. Thus, sea lamprey have to counter the simultaneous challenges of hyposmoregulation in sea water and the generation of large quantities of ammonia due to the …

Changes In Brain Water Content In The Rainbow Trout (Oncorhynchus Mykiss) And In The Goldfish (Carassius Auratus) Due To High External Ammonia Exposure, Phillip Q.H. Pham-Ho

Theses and Dissertations (Comprehensive)

In fishes, hyperammonemia may occur following feeding or exposure to abnormally high concentrations of environmental ammonia due to sewage effluents, agricultural run-off and in crowded aquaculture pens. Increased internal ammonia can result in hyperactivity, convulsions, coma and death. In mammals, it is also associated with potentially fatal brain edema, in which the accumulation of intracellular water results in swelling, increased intracranical pressure and herniation leading to death. Recently it was shown that rainbow trout (Oncorhynchus mykiss) and goldfish (Carassius auratus) experience brain swelling following exposure to high external ammonia (HEA). However, the mechanism of ammonia-induced brain …

The Role Of Oxidative Stress In The Mechanisms Of Ammonia-Induced Brain Swelling And Tolerance In The Goldfish (Carassius Auratus), David F. Jones Lisser Mr.

Theses and Dissertations (Comprehensive)

Toxic build-ups of ammonia can cause potentially fatal brain swelling in mammals, but such swelling is reversible in the anoxia- and ammonia-tolerant goldfish (Carassius auratus). The mechanisms of ammonia-induced brain swelling and tolerance remain elusive, but several studies have suggested a role for reactive oxygen species (ROS), which may damage proteins and lipids in the plasma membrane of astrocytes in the brain. As a result, osmotic gradients across cell membranes may be altered leading to water uptake by astrocytes and swelling. While a role for ROS has been proposed in mammals, no studies have addressed this question in …

Distribution And Elimination Of 3-Trifluoromethyl-4-Nitrophenol (Tfm) By Sea Lamprey (Petromyzon Marinus) And Non-Target, Rainbow Trout (Oncorhynchus Mykiss) And Lake Sturgeon (Acipenser Fulvescens), Michael W. Le Clair

Theses and Dissertations (Comprehensive)

The pesticide, 3-trifluoromethyl-4-nitrophenol (TFM), has been highly successful in the control of sea lamprey (Petromyzon marinus) populations in the Great Lakes. Treatments with TFM involve applying it to streams, where it targets larval sea lamprey which live burrowed in the stream substrate. While the toxic mechanism of TFM has been elucidated, and its effects on sea lamprey described, its effects on non-target fish species such as rainbow trout (Oncorhynchus mykiss) and lake sturgeon (Acipenser fulvescens) are not as well understood. The present work demonstrated that rainbow trout show a great capacity to detoxify the lampricide using glucuronidation, when exposed to …

Mechanisms Of Nitrogenous Waste Excretion During The Complex Life Cycle Of The Sea Lamprey (Petromyzon Marinus), James M. Neal Mr.

Theses and Dissertations (Comprehensive)

Sea lampreys (Petromyzon marinus) are a phylogenetically ancient jawless fish, with a multi-staged life cycle characterized by a prolonged suspension-feeding larval stage, which is followed by metamorphosis into parasitic lampreys that feed on the protein-rich blood of fishes. The switch from a nutrient poor to protein-rich diet in the sea lamprey is associated with an increased capacity to deaminate excess amino acids and to excrete ammonia and urea following metamorphosis. The focus of this thesis was to determine if changes in nitrogenous waste transporter protein abundance facilitate ammonia and urea excretion during different stages of the sea lamprey …