Effect of temperature on growth, survival, and chronic stress responses of Arctic Grayling juveniles.

Arctic Grayling are Holarctically distributed, with a single native population in the conterminous United States occurring in the Big Hole River, Montana, where water temperatures can fluctuate throughout the year from 8 to 18 °C. A gradual increase in mean water temperature has been reported in this river over the past 20 years due to riparian habitat changes and climate change effects. We hypothesized that exposing Arctic Grayling to higher temperatures would result in lower survival, decreased growth, and increased stress responses.

Investigation of the suitability of 3 insect meals as protein sources for rainbow trout (Oncorhynchus mykiss).

An in vivo trial was conducted to determine the apparent digestibility coefficients (ADCs) of insect meals for rainbow trout, Oncorhynchus mykiss. Rainbow trout (approximately 370 g ± 23 g, mean ± SD initial weight) were stocked 25 per tank into 400-liter tanks. Fish were fed a reference diet, or 1 of 5 test diets created by blending the reference diet in a 70:30 ratio (dry-weight basis) with menhaden fish meal (MFM), 2 house cricket (Acheta domesticus) meals (cricket A and cricket B), Galleria mellonella meal, and yellow mealworm (Tenebrio molitor) meal.

Evaluation of a hepatic biomarker of nutritional imbalance in juvenile red drum () fed 60% soybean meal-based diets using NMR-based metabolomics.

A 12-week feeding trial with juvenile red drum () fed high-soybean meal (SBM) diets was conducted to investigate a putative biomarker of nutritional imbalance, N-formimino-L-glutamate (FIGLU). Three fishmeal-free, 60% SBM pelleted diets (named B12, Fol, and Met, respectively) were tested to evaluate the effects on growth performance and tissue metabolite profiles of supplementation of vitamin B (0.012 mg/kg), folate (10 mg/kg), methionine (1 g/kg) respectively, above basal supplementation levels.

Validation of a microwave energy meter to non-lethally estimate energetic reserves in adult sturgeon.

Whole-body (WB) energetic reserves influence fish survival, growth, and reproduction but are typically quantified using lethal methods ( proximate analyses) or interpreted through body condition indices. Energetic reserves can impact population dynamics through influences on growth rates, age-at-first-reproductive-maturity, and spawning periodicity at the individual-fish level, especially in long-lived sturgeon species. Therefore, a non-lethal tool to track the energetic reserves of endangered sturgeon populations could inform adaptive management and further our understanding of the sturgeon's biology.

Investigation of graded levels of soybean meal diets for red drum, Sciaenops ocellatus, using quantitative PCR derived biomarkers.

A twelve-week feeding trial was conducted to examine potential metabolic and gene expression changes that occur in juvenile red drum, Sciaenops ocellatus, fed diets with increasing soybean meal inclusion. Significant reduction in fish performance characteristics (feed consumption, weight gain, final weight) was observed within the soybean meal based diets as soybean meal level increased (R, linear regression); however, all soybean meal based diets performed statistically equivalent in regards to performance characteristics (weight gain, feed conversion ratio, condition factor, etc.) to a commercial (45% crude protein and 16% crude lipid) reference diet (R, ANOVA).

Effects of high-soy diet on S100 gene expression in liver and intestine of rainbow trout (Oncorhynchus mykiss).

The current study examines expression of S100 genes, a group of calcium-sensing proteins poorly characterized in fishes. In mammals, these proteins are known to play roles beyond calcium-signaling, including mediation of inflammatory processes. Some S100 proteins also serve as biomarkers for a variety of autoinflammatory conditions.

Investigation of graded-level soybean meal diets in red drum (Sciaenops ocellatus) using NMR-based metabolomics analysis.

We investigated changes in the metabolome in juvenile red drum (Sciaenops ocellatus) induced by increasing amounts of soybean meal (0% to 60%) in extruded, fishmeal-free diets using a nuclear magnetic resonance spectroscopy (NMR)-based metabolomics approach in a 12-week feeding trial. All of the diets were composed of ≈40% total crude protein, ≈11% total crude lipid and were energetically balanced. A fishmeal-containing, commercial extruded diet was used as a control diet throughout the trial.

Water system is a controlling variable modulating bacterial diversity of gastrointestinal tract and performance in rainbow trout.

A two-phase feeding study evaluating performance of rainbow trout and comparing luminal and mucosal gastrointestinal tract (GIT) bacterial community compositions when fed two alternative protein diets in two rearing systems was conducted. Alternative protein diets (animal protein and plant protein diets) balanced with crystalline amino acids: lysine, methionine and threonine or unbalanced, were fed to rainbow trout in two separate water systems (recirculating (RR) and flow-through (FF)) for a period of 16 weeks. The four diets, each contained 38% digestible protein and 20% fats, were fed to rainbow trout with an average weight of 12.

Effect of fasting on body composition and responses to stress in sunshine bass.

The integrated responses of the hormonal regulation of growth and stress in sunshine bass (Morone chrysops X Morone saxatilis) as regulated by feed deprivation were investigated. Groups of fish were fed 1.5% of the body weight per day or offered no feed for 4weeks.

Determination of relative protein degradation activity at different life stages in rainbow trout (Oncorhynchus mykiss).

Rainbow trout were reared from 5 g to approximately 400 g on a diet formulated to supply the required protein from either fishmeal or plant proteins. The fish were sampled at every weight doubling and liver and muscle samples were obtained. From these tissue samples RNA and protein were isolated and analyzed for the expression of a number of muscle regulatory and protein degradation genes and enzymatic activity for proteins involved in the caspase, calpain, and ubiquitin-proteasome pathways for protein proteolysis.