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Internal Vertebral Morphology Of Bony Fishes Matches The Mechanical Demands Of Different Environments, Dana Baxter, Karly E. Cohen, Cassandra M. Donatelli, Eric D. Tytell

Engineering Faculty Articles and Research

Fishes have repeatedly evolved characteristic body shapes depending on how close they live to the substrate. Pelagic fishes live in open water and typically have narrow, streamlined body shapes; benthic and demersal fishes live close to the substrate; and demersal fishes often have deeper bodies. These shape differences are often associated with behavioral differences: pelagic fishes swim nearly constantly, demersal fishes tend to maneuver near the substrate, and benthic fishes often lie in wait on the substrate. We hypothesized that these morphological and behavioral differences would be reflected in the mechanical properties of the body, and specifically in vertebral column …

Novel Quantification And Localization Of Water And Solute Transporters In The Tissues Of The Spiney Dogfish (Squalus Acanthias), Tolulope B. Ojo

College of Graduate Studies: Theses & 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 …

Dna Barcoding Reveals A New Morphotype Of The Sugar Kelp, Saccharina Latissima, Dallin Brimley, Zakery Ford, Travis Gould, Brandon Guerra, Emily Haggett, Ian Jones, Elyse Johnson, Ken Peterson, Matthew Prout

Thinking Matters Symposium Archive

Phytoplankton blooms follow predictable annual cycles in the Gulf of Maine, characterized by a large spring bloom and a smaller bloom in the fall. Marine phytoplankton form the foundation of primary production in Gulf of Maine waters, and thus community changes in composition, and abundance could have cascading effects on our coastal ecosystems.

We set out to monitor the community composition, diversity, and abundance of the spring micro-phytoplankton bloom, at a Friends of Casco Bay water quality monitoring site, in South Portland, Maine. The Gulf of Maine is experiencing accelerated warming rates, and this type of monitoring can aid in …

Application Of A Bioenergetics Framework For Assessing Sub-Lethal Effects Of Pollutants In The Freshwater Mussel Elliptio Complanata, Christopher G. Goodchild

All Theses And Dissertations

Although biomarkers are frequently used to assess sublethal effects of contaminants, a lack of mechanistic linkages to higher-level effects limits the predictive power of biomarkers. Bioenergetics has been proposed as a framework for linking cellular effects to whole-animal effects. We investigated sublethal effects of exposure to wastewater treatment facility effluent in freshwater mussels in situ, thereby capturing ecologically relevant exposure conditions. Our study focused on the energetic biomarker AMP-activated protein kinase (AMPK), while also considering more traditional biomarkers like heat shock proteins (HSP70), and antioxidant enzymes (i.e., superoxide dismutase (SOD), glutathione-S-transferase (GST)). We examined biomarkers at mRNA and protein levels. …

Enhancing Thermal Tolerance By Eliminating The Pejus Range: A Comparative Study With Three Decapod Crustaceans, Jennifer A. Jost, Stephanie M. Podolski, Markus Frederich

Marine Sciences Faculty Publications

Marine invertebrates in the intertidal and subtidal zones are often exposed to highly variable environmental conditions, especially rapid changes in temperature. The ability to survive at different temperatures has previously been described using an extended version of Shelford’s law of tolerance, with optimum, pejus (Latin: ‘turning worse’), and pessimum ranges, and the respective thresholds, critical (Tc) and pejus (Tp) temperatures, that mark the transition from one range into the next. The width of the pejus range, in which the scope for activity gradually declines, varies among species. We tested the hypothesis that the width of the …

Reproductive Life History Of Fundulus Jenkensi And Comparative Development Of Five Sympatric Fundulid Species, Eric Thomas Lang

Master's Theses

Fundulus jenkinsi is recognized federally and within the state of Mississippi as a Species of Concern. Little is known about the life history of this coastal killifish, but a detailed reproductive histology study of F. jenkinsi and a diagnostic key of the early life stages of select members of Fundulidae can provide the foundation needed to accurately identify it and quantify reproductive parameters in this rare species in need of conservation. Monthly gonadosomatic index (GSI) of male and female F. jenkinsi were documented, and spawning phases and oocyte stages were examined using reproductive histology. In addition, various stages of …

Distribution Of Allatostatin C-Like Immunoreactivity In The Central Nervous System Of The Copepod Crustacean Calanus Finmarchicus, Caroline H. Wilson, Andrew E. Christie

Health Sciences and Kinesiology Faculty Articles

The C-type allatostatins (C-ASTs) are a family of highly pleiotropic arthropod neuropeptides. In crustaceans, transcriptomic/mass spectral studies have identified C-ASTs in the nervous systems of many species; the cellular distributions of these peptides remain unknown. Here, the distribution of C-AST was mapped in the nervous system of the copepod Calanus finmarchicus, the major contributor to the North Atlantic’s zooplanktonic biomass; C-AST-immunopositive neurons were identified in the protocerebrum, in several peripheral ganglia associated with feeding appendages, and in the ganglia controlling the swimming legs, with immunopositive axons present throughout the ventral nerve cord. In addition, axons innervating the dorsal longitudinal …

Differential Response Of Amp Activated Protein Kinase (Ampk) And Hsp70 To Temperature Stress In The Gastropod, Nucella Lapillus, Emily Zimmermann

All Theses And Dissertations

Populations of the gastropod Nucella lapillus are polymorphic for shell color, with light-colored shells predominating on warmer, wave-protected shores and dark-colored shells limited primarily to cooler, wave-exposed shores. During thermal stress, darker shells attain higher body temperatures than lighter shells. These results suggest that heat stress may determine field distribution patterns. However, there is currently little evidence of physiological consequences of thermal stress in these organisms. Following the guiding hypothesis that heat stress leads to cellular energy depletion, we explored whether the central energy regulator AMP-activated Protein Kinase (AMPK) is activated by heat stress. We compared this response in both …

Temperature Tolerance In Crustaceans: Critical Temperatures And The Heart, Lindsay Haupt (Murray-Miller)

All Theses And Dissertations

At certain upper and lower threshold temperatures (critical temperatures (Tc) crustaceans switch to anaerobic metabolism despite sufficient oxygen availability in the environment. I tested the hypothesis that failure of the heart at critical temperatures leads to insufficient oxygen delivery and subsequent anaerobiosis in peripheral tissues.

I exposed rock crabs, Cancer irroratus, as whole animals, and their buffer-perfused semi-isolated hearts to a progressive temperature increase, while monitoring heart rate and lactate accumulation. The whole animals heart rate increased with temperature following a Q₁₀ of 2.8. An abrupt decline in heart rate occurred at 25°C and lactate accumulation occurred between …

Inventory Of Lake Studies In Maine, Charles F. Wallace Jr., James M. Strunk

Maine Collection

Inventory of Lake Studies in Maine

By Charles F. Wallace, Jr. and James M. Strunk

State Planning Office, Water Resources Planning Division, July 1973.

"Printed under Appropriation Number 4248.5 and financially assisted by planning grants from the United States Water Resources Council Title III funds."

Contents: Introduction / Investigating Agencies / Federal Agencies / State Agencies / Regional Planning Commissions and Economic Development Districts / Maine Colleges and Universities / Private / Other Private / Other / Appendices