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Full-Text Articles in Life Sciences
Novel Quantification And Localization Of Water And Solute Transporters In The Tissues Of The Spiney Dogfish (Squalus Acanthias), Tolulope B. Ojo
Novel Quantification And Localization Of Water And Solute Transporters In The Tissues Of The Spiney Dogfish (Squalus Acanthias), Tolulope B. Ojo
Electronic Theses and Dissertations
The dogfish, Squalus acanthias is a marine cartilaginous elasmobranch found in the North Atlantic and Pacific oceans. Dogfish synthesize and excrete urea as a product of nitrogen metabolism. They also convert ammonia into urea and retain this urea, such that their plasma is isosmotic or slightly hyperosmotic to the surrounding seawater. To facilitate the regulation of body fluid and to maintain ionic concentrations and osmotic pressure, Dogfish use ion and solute transporters (e.g., NCC, UT-1) and aquaporin water channel proteins. Studies have identified some of the aquaporin genes in the elasmobranch genome, but their functions are mostly uncharacterized. Recent transcriptomic …
Physiological Response Of Elasmobrachs During Propofol Immersion, Matthew Levendosky
Physiological Response Of Elasmobrachs During Propofol Immersion, Matthew Levendosky
Electronic Theses and Dissertations
Sensory experiments require anesthesia so the animal is immobilized, however fish anesthetics have shown to depress sensory responses. Newer anesthetics may offer similar anesthetic relief, but differ in means of action so sensory responses may be unaffected. Propofol has been used intravenously on small elasmobranchs but may provide prolonged effects if used as an immersion anesthetic. Objectives of this study were 1. Determine appropriate concentration of anesthetic to minimize induction and recovery for animals anesthetized at a surgical plane of anesthesia and 2. Measure physiological response of the pupil to light stimuli during anesthetic immersion. To address these objectives, I …
Environmental And Physiological Regulation Of Yellow Stingray Color Change, Theresa Rose Gunn
Environmental And Physiological Regulation Of Yellow Stingray Color Change, Theresa Rose Gunn
Electronic Theses and Dissertations
Many reef fishes exhibit dynamic coloration and body patterns that can change under nervous or hormonal control. Several species of benthic sharks and rays likely alter melanin in the skin to provide background matching for camouflage. The yellow stingray (Urobatis jamaicensis) is a benthically-oriented elasmobranch with elaborate spot patterns that provide effective camouflage within its habitats. This patterning, when coupled with the ability to alter melanin in response to background color, could increase background matching effectiveness in these species. The yellow stingray has been anecdotally noted to lighten or darken skin color.However, it is unclear whether this type …
Characterization Of Andrenocortical Tissue Morphology, Histology, And Steroid Synthesis Among Finetooth (Carcharhinus Isodon), Blacktip (Carcharhinus Limbatus), Atlantic Sharpnose (Rhizoprionodon Terraenovae), And Bonnethead (Sphyrna Tiburo) Sharks, Danielle Elizabeth Bailey
Master's Theses
Adrenocortical (interrenal) tissue is composed of steroidogenic cells that produce corticosteroids involved in the stress response and hydromineral balance. Previous research characterizing the elasmobranch interrenal suggests that the number of interrenal bodies that produce the single primary corticosteroid, 1a-hydroxycorticosterone (1a-OHB), varies among species. However, potential species-specific differences in the amount of interrenal tissue and major steroid products produced have been understudied. To address this critical gap in our understanding of elasmobranch biology, this study examined interrenal morphology, cell structure, steroidogenic enzyme distribution (3bHSD), and steroid production in four shark species: Finetooth Carcharhinus isodon, Blacktip Carcharhinus limbatus, Atlantic Sharpnose …
The Elasmobranch-Microbe Relationship: Trimethylamine N-Oxide Synthesis, Urea Hydrolysis, And Microbe-Osmolyte Interactions In The Atlantic Stingray, Dasyatis Sabina, Kaitlin Kelly Doucette
The Elasmobranch-Microbe Relationship: Trimethylamine N-Oxide Synthesis, Urea Hydrolysis, And Microbe-Osmolyte Interactions In The Atlantic Stingray, Dasyatis Sabina, Kaitlin Kelly Doucette
Master's Theses
The elasmobranch osmoregulatory strategy is predicated on the accumulation of nitrogenous compounds, primarily urea and trimethylamine n¬-oxide (TMAO). Despite the abundance of these plasma osmolytes, it is notable that elasmobranchs appear to lack urease and TMA oxidase (Tmase), enzymes that scavenge urea-nitrogen and synthesize TMAO, respectively. However, urease and Tmase are found in many species of bacteria. Therefore, I hypothesized that intestinal bacteria are responsible for urease and Tmase activity in elasmobranchs. Absent dietary nitrogen sources, I evaluated the effects of reduced intestinal microbiota on osmoregulation in Atlantic stingray (Dasyatis sabina) in vivo. D. sabina were given …
Exploring The Glucocorticoid Actions Of 1Α-Hydroxycorticosterone (1Α-Oh-B) In The Elasmobranch Fishes, Faith Nichole Lambert
Exploring The Glucocorticoid Actions Of 1Α-Hydroxycorticosterone (1Α-Oh-B) In The Elasmobranch Fishes, Faith Nichole Lambert
Master's Theses
The corticosteroid 1α-hydroxycorticosterone (1α-OH-B) is unique to the elasmobranch fishes. It is thought that 1α-OH-B acts as both the primary glucocorticoid (GC) and mineralocorticoid (MC) in these fishes, a dual role analogous to that of cortisol in the teleost fishes. The MC characteristics of 1α-OH-B are well supported, but data supporting its GC functions are lacking. In this study, the putative GC actions of 1α-OH-B were examined. The first experiment characterized the physiological stress response of the Atlantic stingray (Dasyatis sabina) to air exposure, with particular regards to the roles of corticosteroids and metabolic fuels. Results demonstrate that …