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Effects Of Wet Aging On Water-Soluble Flavor Compounds, Descriptive Flavor, Consumer Acceptability, And Willingness-To-Pay Of Beef Longissimus Lumborum Steaks, Shangshang Wang

Theses and Dissertations

This study examined the effects of wet aging on water-soluble flavor compounds, descriptive flavor, consumer acceptability, and willingness-to-pay of beef strip steaks. Twenty USDA Select boneless beef loins (NAMP #180) were dorsally divided into four equal portions, which were randomized to receive either 0, 7, 14, or 21 d of wet aging. Short-chained peptide concentration increased from 4.11 mg/g on d 0 to 5.12 mg/g on d 7 (P = 0.011) and subsequently increased to 7.14 mg/g on d 21 (P < 0.001). Cooked beef contained 1.85 mg/g less short-chained peptides than raw beef (P < 0.001). Wet aging for 21 d increased the concentrations of amino acids, which are precursors for the Maillard reaction, including methionine, threonine, cystine, serine, tryptophan, and phenylalanine (P < 0.001). Wet aging decreased the nucleotide concentrations (P ≤ 0.003) and increased hypoxanthine concentration, a compound that imparts bitter flavor (P …

Increased Coding Potential Of Bovine Herpesvirus 1, Victoria Jefferson

Theses and Dissertations

Bovine respiratory disease (BRD) costs the cattle industry millions of dollars in costs in treatment and loss every year in the United States. A significant pathogen often contributes to BRD is Bovine Herpesvirus 1 (BoHV-1), a double stranded DNA virus with the ability to establish latency in the trigeminal ganglia and neurons. Primary infection with BoHV-1 results in immunosuppression that increases the risk of secondary bacterial infection and pneumonia. Because herpesviruses infect their hosts for life and can be reactivated in times of stress, BoHV-1 can present a recurring risk of BRD. The following research aims to expand the knowledge …

Biophysical Factors Affecting Habitat Suitability For Crassostrea Virginica, Jason D. Tilley

Dissertations

Oyster reefs provide a variety of important ecosystem services. However, the mortality rate of eastern oyster, Crassostrea virginica, the dominant species that produces oyster reefs in the northern Gulf of Mexico, is increasing at an alarming rate due to a variety of abiotic and biological factors. I examined how biophysical factors, including the less-studied fatty acid profiles of the suspended particulate matter on which oysters feed, influenced morphometric condition of C. virginica.

I sampled suspended particulate matter (SPM) and oysters in-situ in the western Mississippi Sound, which historically supported the majority of oyster production in Mississippi waters. Sampling …

Nutritional Evaluation Of Hydroponic Corn Fodder And Its Effect As Substitute For Feed Concentrates For Buffalo Calves, Charity I. Castillo, Phoebe Lyndia T. Llantada, Cyril P. Baltazar, Mary Rose D. Uy-De Guia, Reynald D. Amido, Arnel N. Del Barrio

The Philippine Agricultural Scientist

This study investigated the effects of hydroponic corn fodder on the growth performance of buffalo calves. Twelve Bulgarian Murrah buffalo calves were divided into two treatment groups: T1, fed with Napier grass and starter feed concentrates, and T2, fed with Napier grass, starter feed concentrates, and hydroponic corn fodder, replacing 50% of the starter feed concentrate. The study found no significant differences between the two groups' average total weight gain and average daily gain. However, the average daily feed intake was significantly higher in T2, possibly due to the tender and young nature of the hydroponic corn fodder. Dry matter …

The Influence Of Rusty Crayfish And Zebra Mussel Invasion On Yellow Perch Population Dynamics In North-Central Minnesota Lakes, Kendra Fink

Biology Graduate Theses

Over the last 50 years, Minnesota Department of Natural Resources standard fisheries survey catch rates of Yellow Perch have declined. Yellow Perch Perca flavescens are an important, widespread game fish, are essential prey species for Walleye Sander vitreus and other piscivorous fish and rely greatly on benthic resources through many life stages. Aquatic invasive species (AIS) like rusty crayfish Faxonius rusticus and zebra mussels Dreissena polymorpha have the potential to change water quality, vegetation and prey assemblages in aquatic systems and could cause shifts in energy flow, subsequently altering growth, condition, and maturity of native fish species. In this study, …

Effects Of Dietary Rumen-Protected Choline Supplementation To Periparturient Dairy Cattle On Inflammation, Metabolism, And Performance During An Intramammary Lipopolysaccharide Challenge, Turner H. Swartz, Barry Bradford, Laman Mamedova, Kari Estes

Dairy Science and Food Science Faculty Publications: 2022 to Present

Recent studies have suggested that dietary rumen-protected choline (RPC) supplementation can modulate immune function, attenuate inflammation, and improve performance in periparturient dairy cattle; however, this has yet to be evaluated during a mastitis challenge. Therefore, the objective of this study was to examine the effects of supplementation and dose of RPC on metabolism, inflammation, and performance during an intramammary lipopolysaccharide (LPS) challenge. Parous Holstein cows (parity, mean ± SD, 1.9 ± 1.1 at enrollment) were blocked by calving month and randomly assigned within block to receive either 45 g/d of RPC (20.4 g/d of choline ions; CHOL45, n = 18), …

The Effects Of Sous Vide Cooking And Cysteine Proteases On Instrumental And Sensory Textural Properties Of Lower Value Cuts Of Beef, Ian Smith

All Theses

Sous vide cooking has the potential to increase the value of lower quality cuts of beef. Understanding the textural properties following a cook-chill sous vide process is crucial to maximizing this potential. The use of enzymes may further increase the value of these products if able to positively alter the texture of the final product.

The first research objective was to use instrumental texture analysis to evaluate potential relationships between enzymatic treatments and sous vide processing time of lower value cuts of beef. Three cuts were evaluated: infraspinatus (top blade), semitendinosus (eye of round), and beef tongue. Infraspinatus and semitendinosus …

Novel Protected Gelatin Capsules Containing Fish Oil Mitigated The Effect Of Milk Fat Depression And Reduced Rumen Degradation Compared To Untreated Capsules, Omar Manuel Pena Pena

All Theses

The objective of this study was to assess the effects of feeding gelatin capsules treated with alcoholic solutions of flavoring agents followed by drying containing fish oil on lactation performance, rumen fatty acids content and milk enrichment of fatty acids. In Trial 1, four multiparous ruminally-fistulated Holstein cows were randomly assigned to one of four dietary treatment sequences in a 4 x 4 Latin square design. Treatments consisted of 1) Control with no capsules, 2) Control plus 200 untreated capsules per cow/day, mixed with the TMR; 3) Control plus 200 treated capsules per cow/day placed directly into the rumen, 4) …

Impact Of Reducing Ammonia Concentration By Ozone Technology And Its Potential Improvement On Broiler Performance, Odilpio Quintana Ortega

Graduate Theses and Dissertations

The employment of ozone in livestock production as a means of mitigating ammonia is used for enhancing air quality within animal confinement facilities, such as swine or poultry barns. Ammonia is a byproduct of animal excrement. Elevated ammonia concentrations can adversely affect the well-being of both animals and humans. The aim of this thesis was to investigate the effects of Ozone Technology Machine Unit (OTMU) utilization in poultry barns regarding ammonia concentration and its potential benefit in terms of broilers performance and welfare. In recent years, there has been a significant boom in technological advances. New devices that help mitigate …

The Effects Of Probiotics And Environment On The Swine Gut Microbiome, Bin Zuo

Graduate Theses and Dissertations

The gastrointestinal tract is crucial for nutrient absorption and immune system functionality. It employs a synergistic approach, merging physical and biochemical defenses, to counteract pathogens that enter through dietary or other external routes. This system also facilitates the breakdown of complex carbohydrates, a process beyond the host's innate capacity. In swine, gut microbiota early colonization plays a significant role in several physiological developments, shaped by a variety of determinants including maternal factors and environmental conditions. In the swine industry, the shift to indoor pig farming enhances efficiency but limits soil interaction, potentially impacting gut microbiota diversity. Additionally, the practice of …

Assessing The Morphological And Physiological Traits Of Smooth Brome Pastures Under Long Term Grazing And Nutrient Enrichment In Eastern Nebraska, Hassan Shehab

School of Natural Resources: Dissertations, Theses, and Student Research

Climate change together with the increase in demands for food, feed, fuel, and fiber are becoming a threat to sustainability and resilience of agriculture and pasture lands. Bromus inermis (smooth bromegrass) dominates pastures for cattle grazing in Eastern Nebraska, US, where it is planted in monocultures, and is considered high quality forage because of its palatability and high nutritional value for cattle, especially under intensive management practices. Sustainable management of these pastures is key to long-term resilience. This study aims to assess the performance of smooth bromegrass pastures to the combined effects of long-term management practices (since 2005) of fertilization …

Mapping Density And Distribution Of Ptarmigan And Arctic Ground Squirrels Within Gyrfalcon Breeding Territories In Western Alaska, Michaela L. Gustafson

Boise State University Theses and Dissertations

Shifting climate patterns are modifying Arctic habitats, stressing the need to understand how rapid climate and habitat changes affect Arctic trophic webs. Despite their crucial role in illuminating the impacts of Arctic changes and their ripple effects on predators, like Gyrfalcons, small Arctic primary consumers remain insufficiently studied across their range. To address this gap, I sought to estimate the distribution and abundance of Gyrfalcons' top three prey species (Willow Ptarmigan, Rock Ptarmigan, and Arctic ground squirrels) within Gyrfalcon breeding territories on the Seward Peninsula, Alaska, USA. I also aimed to discern the relationships between different habitats and species’ abundance. …

Unlocking The Mysteries Of Opportunism: Neuroendocrine Insights From An Aseasonal Breeder (Taeniopygia Guttata), Jessica A. Moodie

Graduate Theses and Dissertations (2019 - present)

The regulation of reproductive physiology in animals is mediated by the Hypothalamus-Pituitary-Gonad (HPG) axis. In seasonal breeders, a conserved reciprocal switching of deiodinase enzymes alters thyroid hormone signaling, which controls HPG activity. This study tested the hypothesis that neural regulation of the HPG axis as described in seasonal systems is conserved and repurposed to respond to other cues in aseasonal species. Using water deprivation and nest restriction in the opportunistic Zebra Finch, we were able to create a breeding group and non-breeding group, confirmed by egg laying and changes in ovarian anatomy. Breeding females had clear follicular hierarchy, increased ovary …

Feed Value And Utilization Of Corn Residue: Implications For Cow Performance And Grazing Strategies, Kaylee E. Wheeler

Department of Animal Science: Dissertations, Theses, and Student Research

Two experiments were conducted to determine the correlation of corn residue feed value and utilization on cow performance and potential grazing strategies. A qualitative observation of corn residue grazing by 13 cattle herds across Nebraska was conducted over two years. Based on producer reported grain yields and stocking rates, it was found that these producers were generally not as aggressive as the recommended 1.2 animal unit months (AUM) for each 6,280 kg/ha (100 U.S. bushels/acre) of harvested grain. They stocked 17 to 101% of the recommendation and on average used 63% of the carrying capacity. Across herds, average body condition …

Predicting Body Weight Of Cattle And Nutrient Digestion Of Individual Sweet Bran Components To Improve Beef Cattle Production Efficiency, Dalton J. Anderson

Department of Animal Science: Dissertations, Theses, and Student Research

Efficiency is of high importance to beef cattle producers to ensure that beef cattle are being raised without unnecessary resource use. Two separate experiments were conducted to evaluate potential strategies to improve efficiency in beef cattle production. A metabolism study was conducted to evaluate digestion parameters of individual Sweet Bran components. The objective was to determine the effects of diet components on nutrient digestion and rumen fermentation parameters. The individual components of Sweet Bran (Corn bran, solvent-extracted germ meal, and corn steep liquor) were included at 40% diet dry matter (DM) in a steam-flaked corn (SFC) based diet. A SFC-based …

The Evaluation Of Feed Additives On Reducing Enteric Methane Production From Cattle, Reba L. Colin

Department of Animal Science: Dissertations, Theses, and Student Research

Environmental sustainability can be positively impacted by the inclusion of feed additives to reduce enteric methane production from cattle. Methane production can be affected by feed additives that either alter the rumen environment or act as methanogenesis inhibitors. A reduction in methane from cattle can contribute to meeting carbon neutrality.

A metabolism study was conducted to evaluate Alga 1.0, a product containing bromoform, fed to cattle to evaluate the effects on gas emissions. Treatments were (0, 69, or 103 g/d Alga 1.0) fed in a corn-based diet. Headbox-style indirect calorimeters were used to measure gas emissions. Feeding Alga 1.0 linearly …

The Impact Of Silage Inclusion In Diets With Different Corn Processing And The Effect Of Natural And Conventional Feeding Programs On Finishing Cattle Performance, Jessica L. Miller

Department of Animal Science: Dissertations, Theses, and Student Research

A finishing experiment was conducted to determine the effects of natural and conventional feeding programs on finishing performance of steers and heifers. Factors were conventional and natural feeding programs in steers and heifers. Cattle assigned to the conventional program were fed diets that contained Rumensin (Elanco Animal Health), Tylan (Elanco Animal Health), MGA (Zoetis), and received growth promoting implants whereas cattle in the natural program received neither. Compared to natural fed cattle, G:F was improved by 15.5% when heifers were fed in a conventional program (P < 0.01) and 23.8% when steers were fed in a conventional program (P < 0.01). The incorporation of implants and feed additives within the finishing period increased …

Forages And Technology Management In Growing And Finishing Beef Cattle Systems, Kelton Cole Adair

Department of Animal Science: Dissertations, Theses, and Student Research

A systems study evaluated the effects of an implant [25.7 mg estradiol (Compudose; Elanco Animal Health)] at two rates of gain (LOW: 0.45 kg/d and HIGH: 0.9 kg/d) applied during the winter backgrounding phase in drylot and winter grazing systems and its effects on subsequent phases of production. HIGH supplementation with an implant during the winter backgrounding phase in the drylot system yielded the greatest ending body weight (EBW) during the summer backgrounding phase (P = 0.04). LOW supplementation, without an implant, improved summer backgrounding average daily gain (ADG; P = 0.05) while achieving similar carcass adjusted final body …

Factors Affecting Forage Quality And The Subsequent Response In Production And Energy Metabolism In Lactating Jersey Cows, Kassidy Kate Buse

Department of Animal Science: Dissertations, Theses, and Student Research

Forage quality is the potential of a forage to produce a production response in animals. Because of how essential they are in dairy cattle rations, forages can have major influence on the behavior and production of dairy cattle. In experiment 1, the effect of forage fragility on the rumen environment and digestibility was evaluated. Increasing the inclusion of a less fragile forage led to greater rumen retention time, which resulted in lower rumen pH and greater NDF digestibility. Experiment 2 evaluated the effects of diets high in either corn silage or alfalfa haylage supplemented with either corn- or soybased protein …

Early-Life Supplementation Of Omega-3 Polyunsaturated Fatty Acids Improved Growth And Skeletal Muscle Glucose Metabolism In The Heat Stress-Induced Iugr Neonatal Lamb, Melanie Ryann White

Department of Animal Science: Dissertations, Theses, and Student Research

Our 1^st study determined whether metabolic deficits of IUGR-born neonatal lambs can be improved by ameliorating elevated inflammatory tone. Supplementation with ω-3 polyunsaturated fatty acids (ω-3 PUFA) improved hindlimb insulin-stimulated glucose oxidation rates and basal lactate secretion. Ex vivo skeletal muscle-specific glucose oxidation rates were improved when heightened inflammatory tone was moderated. Pancreatic β cell function in response to hyperglycemia was improved by ω-3 PUFA supplementation. Tempered inflammatory tone also partially recovered skeletal muscle glycogen stores. Thus, we found that targeting heightened inflammatory tone inherent in IUGR-born neonatal lambs moderately improved glucose metabolism and pancreatic β cell …

Relative Hepatotoxocity, Carcinogenicity, And Toxicogenomics Of Select Dehydropyrrolizidine Alkaloids In Mice, Michael J. Clayton

All Graduate Theses and Dissertations, Fall 2023 to Present

Dehydropyrrolizidine alkaloids are arguably the most important plant derived toxins in terms of impact on human and animal health. Dehydropyrrolizidine alkaloids are a large group of chemically related compounds found in 3% of flowering plants worldwide. Human exposure occurs from ingestion of herbal products including teas supplements or contaminated grain. Animals are exposed through contaminated feed or grazing. There are at least 350 identified toxic PAs, from more than 6,000 plants. The toxins primarily cause liver damage, but some are proven to cause cancer. Indidvidual dehydropyrrolizidine alkaloids vary in their toxic effects. Riddelliine is the only dehydropyrrolizidine alkaloid with extensive …

Assessment Of Dietary Energy And Amino Acid Diet Formulation In The Modern Broilers, Matheus Freitas Costa

Graduate Theses and Dissertations

As a result of the advancement of genetics, understanding broiler requirements for dietary energy and amino acids is essential for improving live performance and carcass characteristics. The energy system used to formulate diets in poultry is based on metabolizable energy (ME); this equation can be described as the total amount of energy in the feed minus gases and feces. However, the net energy (NE) system may be the best depiction of the energy utilized by birds for production and maintenance purposes once the heat increment (HI) is measured. Thus, a series of studies were conducted to establish the responsiveness of …

Determination Of P Availability In Feedstuffs And The Effect Of Feedstuffs And Anti-Nutritional Factors On Secretory Iga Production And Host Nutrient Losses In Poultry, Benjamin Parsons

Graduate Theses and Dissertations

The availability of P in feedstuffs and the effect of feedstuffs, feed additives, and anti-nutritional factors on secretory IgA (sIgA) production in chickens were evaluated. A rapid method was developed using the precision-fed rooster assay to evaluate phytic acid disappearance, P digestibility, and phytase efficacy. Further, exogenous phytase was found to be effective at degrading myo-inositol 1,2,3,4,5,6-hexakis, however, the enzyme was less efficient at P release from lower inositol phosphates. The availability of P in feedstuffs was found to be affected by dietary Ca content, where increasing Ca linearly reduced (P < 0.05) both phytic acid hydrolysis and P digestibility. For example, the standardized ileal digestibility of P was reduced from 73 to 47% in soybean meal when the dietary Ca content was increased from 0.30 to 0.75%. The digestibility of P in distillers dried grains with solubles (DDGS) and corn fermented protein (CFP), however, was high across all Ca levels (71 to 80%). Relative P bioavailability based on tibia bone ash was also found to be high for DDGS and CFP, being 81 and 78%, respectively. Upon further evaluation, it was observed that utilizing low dietary Ca levels (0.30%) when P digestibility in individual plant-based feedstuffs was determined overestimated the P digestibility in practical grower diets by up to 16 percentage units. Utilization of higher Ca levels (0.75%) when P digestibility in individual plant-based feedstuffs was determined, however, resulted in calcualted P digestibility values that were within 1 to 3 percentage units of the measured digestibility in practical grower diets. Aside from P, feedstuffs were also evaluated to determine their effect on sIgA production in the intestine. Roosters excreted approximately 6 to 30 mg of sIgA / 24 h. Further, the proportional contribution of sIgA to total endogenous amino acid (AA) losses ranged from 1 to 13%, with the greatest contribution being observed for Trp. The addition of casein to a protein-free diet increased (P < 0.05) sIgA production in both roosters and broiler chickens. There was no change (P > 0.05) in sIgA production compared with the protein-free diet …

An Intersection Of Science & Art: Vitrification Approaches And Open-Fabricated Tools For The Biomedical Model Sea Hare, Aplysia Californica, Allyssa M. Oune

LSU Master's Theses

The California sea hare (Aplysia californica) is an important biomedical model for molecular neurobiology, electrophysiology, learning, and memory due to their well-mapped and large neurons and well-characterized learning capabilities. The National Resource for Aplysia (NRA, University of Miami) maintains large stocks of live animals and relies on regular shipments of wild-caught individuals to maintain genetic diversity. This is labor and cost-intensive, and environmental changes could alter the availability of wild animals increasing the need to preserve this genetic resource. One solution is vitrification, ultra-fast cooling which produces an amorphous glass that minimizes damage to cells. Aplysia californica presents …

University Of Nebraska-Lincoln Agricultural Research Division 121st Annual Report. July 1, 2006 To June 30, 2007., Institute Of Agriculture And Natural Resources

Agricultural Research Division: News and Annual Reports

Our Mission..... 4

Foreword..... 5

Research Highlights..... 6

Faculty Awards and Recognitions....14

Graduate Student Awards and Recognitions...17

Undergraduate Honors Student Research Program...22

Variety and Germplasm Releases....23

Patents.....24

Administration.....25

Administrative Personnel....25

Organizational Chart....26

Administrative Units....27

IANR Research Facilities....28

Faculty.....29

Agricultural/Natural Resources Units....30

Education and Human Sciences Departments...39

Off-Campus Research Centers....40

Interdisciplinary Activities....41

Visiting Scientists/Research Associates....42

Research Projects.....47

Agricultural/Natural Resources Units....47

Education and Human Sciences Departments...52

Off-Campus Research Centers....52

Interdisciplinary Activities....53

Publications.....55

Agricultural/Natural Resources Units....60

Education and Human Sciences Departments...82

Off-Campus Research Centers....85

Research Expenditures....88

Identification Of Biomarkers Of Sub-Lethal Algal Toxin Exposure In Atlantic Salmon (Salmo Salar) And Chinook Salmon (Oncorhynchus Tshawytscha) Using Differential Gene Expression Analysis, Brandon Ellingson

Biology Theses

Atlantic Salmon (Salmo salar) and Chinook Salmon (Oncorhynchus tshawytscha) are important culturally, recreationally, economically, and are a common aquaculture species in Canada and the United States. In the Pacific Northwest, blooms of toxic algae result in millions of dollars annually in losses for salmonid aquaculture producers. Blooms of harmful cyanobacteria produce microcystins which have been linked to net-pen liver disease which has large financial impacts on net pen salmon operations. Microcystin-LR, the most toxic variant, bioaccumulates in the liver and disrupts normal cellular activity by inhibiting protein phosphatases leading to deleterious effects on growth, immune status, and liver function. To …

Factors Affecting Forage Quality And The Subsequent Response In Production And Energy Metabolism In Lactating Jersey Cows, Kassidy Kate Buse

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

Forage quality is the potential of a forage to produce a production response in animals. Because of how essential they are in dairy cattle rations, forages can have major influence on the behavior and production of dairy cattle. In experiment 1, the effect of forage fragility on the rumen environment and digestibility was evaluated. Increasing the inclusion of a less fragile forage led to greater rumen retention time, which resulted in lower rumen pH and greater NDF digestibility. Experiment 2 evaluated the effects of diets high in either corn silage or alfalfa haylage supplemented with either corn- or soy-based protein …

A Novel Machine-Learning Framework Based On A Hierarchy Of Dispute Models For The Identification Of Fish Species Using Multi-Mode Spectroscopy, Mitchell Sueker, Amirreza Daghighi, Alireza Akhbardeh, Nicholas Mackinnon, Gregory Bearman, Insuck Baek, Chansong Hwang, Jianwei Qin, Amanda M. Tabb, Jiahleen Roungchun, Rosalee S. Hellberg, Fartash Vasefi, Moon Kim, Kouhyar Tavakolian, Hossein Kashini Zadeh

Food Science Faculty Articles and Research

Seafood mislabeling rates of approximately 20% have been reported globally. Traditional methods for fish species identification, such as DNA analysis and polymerase chain reaction (PCR), are expensive and time-consuming, and require skilled technicians and specialized equipment. The combination of spectroscopy and machine learning presents a promising approach to overcome these challenges. In our study, we took a comprehensive approach by considering a total of 43 different fish species and employing three modes of spectroscopy: fluorescence (Fluor), and reflectance in the visible near-infrared (VNIR) and short-wave near-infrared (SWIR). To achieve higher accuracies, we developed a novel machine-learning framework, where groups of …

Effect Of Ploidy On Salinity And Temperature Tolerance In Early Life Stages Of The Eastern Oyster (Crassostrea Virginica), Christian Boudreaux, Jessica Pruett, Alexz Carpenter, Kristie Willett, Deborah Gochfeld

Honors Theses

The U.S. Gulf of Mexico contains the largest remaining wild oyster fishery in the world, but populations have declined in recent decades. A growing interest in off-bottom aquaculture that relies on triploid eastern oysters (Crassostrea virginica) has emerged in the Gulf region, yet these faster growing oysters suffer high mortality as adults during low salinity events (< 5 ppt) in warmer summer months. The combined effects of salinity and temperature stressors on early life stages of triploid oysters are unknown. Early life stages are particularly crucial to understand because triploid oysters do not occur naturally and must be reared in hatchery settings, requiring appropriate water conditions to yield the greatest survival and growth. Thus, we tested the effects of different temperatures (28oC and 32oC) and salinities (5, 10, and 15 ppt) on diploid and triploid oysters at three critical production stages: veliger, pediveliger, and spat. Veliger survival was significantly lower for triploids relative to diploid oysters at all experimental conditions, but triploid veligers had faster growth than diploids at 32oC and 15 ppt. Pediveliger settlement was not affected by ploidy type and only reduced at high temperature (32oC) and the lowest salinity (5 ppt). Diploid spat showed highest survival at 28oC and 15 ppt, while triploids survived best at 32oC and 15 ppt. Triploid spat attained greater shell height compared to diploids in our 6-day exposures, but growth decreased for both ploidies at lower salinities. At the salinity and temperature levels examined, diploid early life stages performed best at 28oC and 15 ppt, whereas triploids were more successful at 32oC and 15 ppt. A broader understanding of the combined effects of environmental stressors will improve the success of hatchery production yields and the resulting economic and environmental benefits of the oyster industry.

Structural And Biological Characterization Of Two Freshwater Mussel Shells (Bivalvia: Unionidae), Hülya Şerefli̇şan

Turkish Journal of Zoology

The shell of a freshwater mussel (Mollusca: Bivalvia) is a composite biological material that plays an active role in maintaining ecosystem services. Mussel shells have variable structures both within and between species. In this study, the structural and biological characteristics of the shells of Potomida semirugata and Leguminaia wheatleyi were investigated in order to use freshwater mussel shells as a biological material. Close observation of the microstructure of the shells of the two common freshwater bivalves revealed a variation in construction from the outer periostracum to the inner nacreous layer. In P. semirugata, a polygonal arrangement with columnar prisms …