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The Effects Of Moderate And High Temperatures On Growth, Metabolism, And Blood-Oxygen Affinity In Ictalurus Spp., Brandon Gerhart

Theses and Dissertations

Despite the growing use of hybrid catfish (Ictalurus furcatus × I. punctatus) in aquaculture, few studies have investigated the comparative effects of temperature on physiological performance with other cultured catfish. Therefore, growth, metabolism, and blood-oxygen affinity of blue (I. furcatus), channel (I. punctatus), and hybrid catfish were compared at moderate (23°C) and high (33°C) water temperatures. Channel catfish had the greatest growth and were in better condition compared to blue and hybrid catfish. Hybrid catfish standard metabolic rates did not differ from blue or channel catfish, while hybrid catfish had higher maximum metabolic rates, …

Bleaching Susceptibility Of Aquarium Corals Collected Across Northern Australia, Morgan S. Pratchett, Ciemon F. Caballes, Stephen J. Newman, Shaun Wilson, Vanessa Messmer, Deborah J. Pratchett

Fisheries Research Articles

There are a wide range of Scleractinian corals that are collected for the global reef aquarium market, often from non-reefal environments. The sustainability of coral harvesting is potentially threatened by increasing anthropogenic disturbances and climate change, though it is unknown to what extent many commonly harvested corals are susceptible to environmental change, or actually bleach during marine heatwaves. In this study, we experimentally tested the temperature sensitivity and bleaching susceptibility of six coral species (Homophyllia australis, Micromussa lordhowensis, Catalaphyllia jardinei, Trachyphyllia geoffroyi, Duncanopsammia axifuga, and Euphyllia glabrescens), which are important components of the …

Recolonization Potential For Coho Salmon (Oncorhynchus Kisutch) In Tributaries To The Klamath River After Dam Removal, Max M. Ramos

Cal Poly Humboldt theses and projects

Removal of four major dams on the Klamath River is scheduled to begin in 2023, restoring access to greater than 50 km of historic mainstem habitat for coho salmon. However, mainstem habitat may not be suitable for juvenile coho salmon due to elevated water temperatures and high concentrations of infectious myxospores in the summer and fast water velocities in the winter. Small, cooler tributaries can provide essential habitat for escape from deleterious conditions in the mainstem Klamath River. I used temperature and other physical features of six tributaries to the Klamath River above Iron Gate Dam to assess their capacity …

The Effects Of Light Level And Temperature On Freshwater Microbial Biomass, Production, Enzyme Activity, And Community Composition, Joel Bonney

Master's Theses and Doctoral Dissertations

Algae can stimulate the production of heterotrophic microbes in periphyton communities, but the synergistic effects of light and temperature on this phenomenon are not well understood and have implications on carbon cycling and energy flow. We employed recirculating mesocosms held at different temperatures and light levels and filled with Typha litter and attached microbes to assess these effects. Heterotrophic microbial production was greater in the presence of light, as were some periphytic enzyme activities. Few response variables increased in a near-linear fashion with ascending temperature, suggesting different temperature optima. The strength of heterotrophic microbial production responses to algal photosynthesis did …

Seasonal Temperature Changes In Three Midwestern Wastewater Streams And The Effects On Fish Assemblages And Physiology, Ryan William Sparks

Masters Theses

Midwestern United States undergo extreme temperature and precipitation fluctuations throughout the year, which leads to changing habitats within Illinois river systems. Wastewater treatment facilities have long been used to treat sewage and reduce the organic products in sewage before releasing it into aquatic environments. Wastewater treatment facilities must maintain optimal conditions, especially temperature, for reproduction and growth of facilitated bacteria that break down organic materials in wastewater. The objectives for this study were to determine the thermal effects of wastewater treatment facilities on receiving waters; and secondly, to investigate the influence of these wastewater facilities on fish abundance and assemblages. …

The Biological Stress Response In Bluegill Sunfish (Lepomis Macrochirus) To Variations In Environmental Temperature And Dissolved Oxygen Content., Monique Kellman

Honors College Theses

With the predicted increase in global water temperature and acute hypoxic episodes, knowledge of the effects these stressors can have on local aquatic life is extremely valuable. This study thereby quantified the change in metabolic rate in Bluegill sunfish, in response to increased temperature and low dissolved oxygen concentration, by utilizing intermittent flow respirometry. Both maximum metabolic rate (MMR) and resting metabolic rate (RMR) were determined in response to variations in dissolved oxygen content, specifically > 95% O₂ and 40% O₂. Additionally, three temperature treatment groups were established, with temperatures of 20, 25 and 30°C in order to …

Temperature-Dependent Pathogenicity Of Grouper Iridovirus Of Taiwan (Tgiv), Hsin-I Liu, Ying-Chu Lin, Pinwen Peter Chiou, Hsin-Yiu Chou

Journal of Marine Science and Technology

Grouper iridovirus of Taiwan (TGIV) is one of the most devastating infectious pathogens of grouper fry in Taiwan. As environmental temperature often plays an important role in the outbreak of diseases, we assayed the impact of different temperatures (18, 25 and 32℃) on TGIV infection both in vitro and in vivo. Cytopathic effect (CPE) characterized as cell rounding and lysis were observed in TGIV-infected grouper SB (swim bladder) cells at 25℃ and 32℃, but was absent at 18℃. With temperature rising to 32℃, the presence of pycnotic nuclei and chromatin margination became prominent in the infected cells, indicating an apoptotic …

Effect Of Increased Water Temperature On Warm Water Fish Feeding Behavior And Habitat Use, Eric Walberg

Journal of Undergraduate Research at Minnesota State University, Mankato

Global warming could cause changes in species behavior and life history. Stream fish may be significantly affected by climate change because individuals are restricted in their movements by water systems and other physical factors, preventing migration to locations more thermally suitable. The effect of warmer waters on stream fish could change behavior and affect the fish species survival and ultimately ecosystem function. During my experiment I observed the effects of increased water temperature on the feeding behavior and habitat use of two native Minnesota fish species, black crappie (Pomoxis nigromaculatus) and black bullhead (Ameiurus melas). An increase of 2oC over …

Effects Of Pre-Treatments And Drying Temperatures On The Drying Rate And Qualityof African Catfish (Claris Gariepinus), Michael Ayodele Omodara, Adesoji Matthew Olaniyan

Michael Ayodele Omodara

Effects of pre-treatments and drying temperatures on the drying rate and the quality of African Catfish Clarias gariepinus was examined by drying samples of catfish under four different temperatures (40 0C, 45 0C, 50 0C and 55 0C) and four different pre-treatment methods (Salting, Sugaring, Blanching, and Control) using an experimental dryer. Drying of the fish samples for all the pre-treatments at 40 0C to 55 0C occurred in the falling rate period only showing that the predominant mechanism of mass transfer in drying process of catfish is that of internal mass transfer. The drying rate increases with increase in …

Influence Of Temperature On Yolk Resorption By Centropomus Undecimalis Larvae, Claudia Catalina Baron-Aguilar

USF Tampa Graduate Theses and Dissertations

In an effort to determine the optimal temperature for rearing Centropomus undecimalis larvae during the yolk resorption period, larval development was measured under four different temperature regimes (23, 25, 28 and 31 °C). The eggs were incubated at 28 °C until hatching, which occurred at about 17 hours post-fertilization. After hatching, temperatures were adjusted to the respective treatment levels. Measurements were collected from 25 individual larvae across rearing temperatures at the following pre-determined time intervals: at hatching, 24 hours post hatch (hph), 48 hph, and 72 hph. Morphometric measurements were obtained from photomicrographs, including yolk sac length and height, oil …

Assessing Linkages Among Landscape Characteristics, Stream Habitat, And Macroinvertebrate Communities In The Idaho Batholith Ecoregion, Andrew C. Hill

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Understanding the composition of lotic communities and the landscape processes and habitat characteristics that shape them is one of the main challenges confronting stream ecologists. In order to better understand the linkages among landscape processes, stream habitat, and biological communities and to understand how accurately our measurements represent important factors influencing biological communities, it is important to test explicit hypotheses regarding these linkages. Increasing our understanding of aquatic communities in a hierarchical context and recognizing how well our measurements represent factors structuring aquatic communities will help managers better evaluate the influence of land management practices on aquatic ecosystems, direct conservation …

Slides: Groundwater Declines, Climate Change And Approaches To Adaptation, Katharine Jacobs

Western Water Law, Policy and Management: Ripples, Currents, and New Channels for Inquiry (Martz Summer Conference, June 3-5)

Presenter: Katharine Jacobs, Director of the Arizona Water Institute, University of Arizona

37 slides

A Sex-Linked Allele, Autosomal Modifiers And Temperature-Dependence Appear To Regulate Melanism In Male Mosquitofish (Gambusia Holbrooki), Lisa Horth

Biological Sciences Faculty Publications

About 1% of male mosquitofish (Gambusia holbrooki) express melanic (mottled-black) body coloration, which differs dramatically from the wild-type, silvery-gray coloration. Here, I report on the genetic inheritance pattern of melanic coloration, which indicates Y-linkage, and at least one autosomal modifier. Phenotypic expression of melanism is also affected by temperature. Expression is constitutive ( temperature insensitive) in some populations, inducible ( temperature sensitive) in others. Constitutive and inducible expression occur among geographically proximal populations. However, males from any single population demonstrate the same constitutive or inducible expression pattern as one another. The F1 males from inter-population crosses demonstrate temperature-related …

Habitat Selection By Lacustrine Rainbow Trout Within Gradients Of Temperature, Oxygen, And Food Availability, Chris Luecke, D. Teuscher

Watershed Sciences Faculty Publications

Rainbow trout (Oncorhynchus mykiss [Walbaum]) in Castle Lake, California were concentrated at certain depths during day and evening hours. A fish bioenergetics simulation model based on vertical gradients of temperature, oxygen concentration, and food availability indicated that rainbow trout selected habitats that maximized growth rate. In 1 of the 2 years of study, a strong pattern of diel vertical migration of rainbow trout was evident and was associated with vertical migrations of daphnids in the lake. The simulation model correctly predicted the occurrence and magnitude of fish migration. During the day some trout resided at depths with little potential for …

An Empirical Model Of Gastric Evacuation Rates For Fish And An Analysis Of Digestion In Piscivorous Brown Trout, E. He, Wayne A. Wurtsbaugh

Watershed Sciences Faculty Publications

The gastric evacuation rates of brown trout Salmo trutta (0.9–1.6 kg) feeding on fingerling rainbow trout Oncorhynchus mykiss (3.5–7.6 g) were measured in the laboratory at five temperatures (4.5, 9.0, 14.0, 19.0, and 22.5°C). Instantaneous gut evacuation rates (Re) increased exponentially with temperature (T): Re = 0.053se^0.073T, r^2 = 0.98; they varyied from 7%sh^–1 at 4.5°C to 29%sh^–1 at 22.5°C. Linear regressions described the relationship between time and qualitative measures of fish digestion, thus allowing investigators to determine how long an ingested fish would be identifiable at different temperatures. An analysis of published evacuation rates (N = 121) of 22 …

Growth And Activity Of Juvenile Mosquitofish: Temperature And Ration Effects, Wayne A. Wurtsbaugh, J. Cech

Watershed Sciences Faculty Publications

The effects of constant temperatures (10, 15, 20, 25, 30, and 35 C) and ration size on the growth rates and activity of juvenile mosquitofish Gambusia affinis (mean wet weight, about 20 mg) were measured in laboratory experiments. On ad libitum rations of Tubifex spp. worms, food-consumption rates of mosquitofish were very high, ranging from 7% dry body weight/day at 10 C to 83%/day at 35 C. Growth increased from 0% dry body weight/day at 10 C to 21%/day at 30 C and declined slightly at 35 C. Gross efficiencies (100 growth/food consumption) increased from 0 at 10 C to …

Aspects Of Larval Ecology Of Squilla Empusa (Crustacea, Stomatopoda) In Chesapeake Bay, Steven G. Morgan

OES Faculty Publications

Larvae of Squilla empusa were collected from the plankton and were laboratory-reared in 16 combinations of temperature and salinity to determine their tolerances. Larvae survived longer and molted more frequently when reared at 25%, and 20° or 25° C, which corresponds to the natural conditions of Chesapeake Bay when the larvae were collected.

A 2 year planktonic survey conducted in the lower region of the bay by the Virginia Institute of Marine Sciences was compared with a survey made at the bay mouth in 1976. The seasonal occurrence of Squilla empusa larvae extended from the last week of July until …

Temperature And Salinity Tolerance Of The Larvae Of The Sand Shrimp, Crangon Septemspinosa (Say), Karen Lyttle Hinsman

OES Theses and Dissertations

The effects of temperature and salinity on the larval development of the sand shrimp, Crangon septemspinosa, were investigated in the laboratory using 30 combinations of temperature and salinity in a five by six factorial experiment. The five temperatures were 5°c, 10°c, 15°c, 20°c, and 25°c and the six salinities were 10°/oo, 15°/oo, 20°/oo, 25°/oo, 30°/oo and 35°/oo. Thirty-six larvae were used for each temperature-salinity combination. Temperature and salinity produced significant differences (1% level) in survival and the duration of larval development. Highest survival occurred at 15°c and 20°/oo. At optimum temperatures (15°c to 20°c) larvae exhibited the broadest tolerance …