Bass Production Research Articles

A Content Analysis Study of Distortion's Influence on Drum and Bass Music Production

This study uses content analysis and draws upon aesthetic theory and technological determinism as theoretical frameworks to explore contemporary approaches to the use of distortion within drum and bass production. To achieve this, it investigates online video tutorials created by professional drum and bass producers and online content creators in order to extract insights into their common working practice when using distortion in their work. The analysis highlights a prevalent use of aggressive distortion to transform bass timbres, which is a trend originating in the 1990s that continues to shape the genre's evolving aesthetic. This research provides unique insights into the evolution. and impact of distortion and shows how established techniques persist while subtly evolving within the ever-changing production ecosystem.

Characteristics of Water Environment and Intestinal Microbial Community of Largemouth Bass (Micropterus salmoides) Cultured Under Biofloc Model

To investigate the effects of biofloc mode on the water environment and intestinal microbial community structure of largemouth bass, a 60-day culture experiment was conducted without water replacement in 300-L glass tanks. The experiment included a control group and a biofloc group, each with three replicates. The results showed the following: (i) the richness and diversity of the water environment and fish intestinal microbial community increased under the biofloc model; (ii) Proteobacteria, Patescibacteria, and Bacteroidota were the dominant phyla in the water environment of largemouth bass, while Proteobacteria, Firmicutes, Bacteroidota, Patescibacteria, and Actinobacteriota were the dominant phyla in the gut of largemouth bass. However, differences in the relative abundance and community structure of microorganisms were observed between the two groups, suggesting that the biofloc system impacts both the water environment and intestinal microbial community structure in largemouth bass culture. (iii) A correlation analysis between water quality indices and enzyme activity with microbial abundance revealed that microbial community composition could effectively reflect water quality and fish physiological health. Based on the analysis of microbial community structure, this study offers a theoretical foundation for integrating largemouth bass culture with the biofloc system, and provides valuable data for future health management and water quality control in largemouth bass production.

Copper toxicity in juvenile largemouth bass (Micropterus salmoides): acute toxicity bioassay and oxidative stress response in gut and kidney

Aquaculture intensification has resulted in serious disease outbreaks in largemouth bass production. Compounds containing copper (Cu) are widely used as therapeutic agents in aquaculture. Currently, Cu misuse has been a severe issue in largemouth bass farming. However, few investigations have been performed on Cu toxicity in largemouth bass so far. In this study, an acute and a chronic toxicity test was carried out to determine the toxicity and the recommended dose of waterborne Cu in largemouth bass. In the acute toxicity bioassay, fish (2.58 ± 0.03 g) were exposed to 0 (control), 3, 6, 9, 18, or 30 mg/L Cu, and the results showed that the 96-h LC50 of waterborne Cu was 12.78 mg/L. Then a 30-day chronic toxicity test containing six treatments (i.e., 0, 51.3, 164, 513, 1640, and 5130 μg/L Cu) was conducted to investigate the influence of Cu on intestinal and renal health in terms of oxidative stress in juvenile largemouth bass (2.69 ± 0.02 g). The results showed that Cu concentrations at and above 51.3 μg/L significantly increased the malondialdehyde contents (in the intestine) and simultaneously decreased total superoxide dismutase activity levels (in the intestine and kidney), glutathione peroxidase activity levels (in the kidney), and reduced glutathione contents (in the kidney), compared to control. In contrast to control, fish exposed to high Cu concentrations (at and above 1640 μg/L) demonstrated lower catalase activity levels in the intestine and kidney. Based on the findings in the study, waterborne Cu content for largemouth bass farming was recommended to be less than 51.3 μg/L.

Evaluation of epitope vaccine based on phage display technology for largemouth bass virus

Largemouth bass virus (LMBV), as a serious aquatic animal virus, has resulted in significant economic losses to the bass farming industry. Currently, vaccination is considered an effective measure for preventing LMBV infection and enhancing largemouth bass (Micropterus salmoides) production. In the study, we determined the targets of specific antibodies in serum from the LMBV survivors by panning a Ph.D.-12 phage library, and high-affinity targeted peptides (P1 and P2) were synthesized. Afterwards, the epitope vaccines were prepared by combining peptides with Freund's complete adjuvant, and inoculated into largemouth bass for in vivo validation. The results indicated that the specific phage enrichment rate was up to 487 times after four rounds of panning, and epitope vaccines showed a good immune response. Furthermore, immune-related parameters in largemouth bass immunized with Adjuvant-P1 and Adjuvant-P2 (20 μg/g) epitope vaccines were considerably greater than in those immunized with Adjuvant-P1 and Adjuvant-P2 (5 μg/g) epitope vaccines. During 14 days post infection, the survival of largemouth bass treated with Adjuvant-P1 and Adjuvant-P2 (20 μg/g) were 55.18% and 51.72%, respectively. These results indicated that P1 and P2 can serve as candidate antigens for the prevention and treatment of LMBV.

The impact of cottonseed meal condition on water quality, zooplankton densities, and sunshine bass production when used as an organic fertilizer in ponds

AbstractObjectiveCottonseed meal is applied to sunshine bass (female White Bass Morone chrysops × male Striped Bass M. saxatilis) fry rearing ponds as an organic fertilizer to stimulate plankton development. The efficacy of cottonseed meal as a fertilizer following long‐term storage and degradation is unknown. The use of degraded and undegraded cottonseed meal were compared during the production of sunshine bass fingerlings in lined 0.4‐ha ponds.MethodsFilling ponds were fertilized repeatedly between 13 days before and 6 days after fry stocking, and water quality, zooplankton, and 41–48‐day fingerling production were monitored. Adequate phytoplankton and zooplankton densities were maintained using cottonseed meal of both conditions.ResultCottonseed meal condition had no significant impact on any fish production metric. The degraded cottonseed meal appeared to release nitrogen more readily as indicated by higher prestocking NH3‐N concentrations. Higher nutrient availability likely stimulated primary productivity at a faster rate, leading to higher dissolved oxygen, pH, and zooplankton densities during the first half of the pond cycle. The ponds fertilized with degraded cottonseed meal required more intensive water quality management to maintain adequate dissolved oxygen and pH for sunshine bass fry. However, poststocking water quality parameters were within species tolerance ranges.ConclusionThe study confirmed that degraded cottonseed meal can be used as an organic fertilizer in sunshine bass fry rearing ponds without compromising fingerling production, provided ponds are managed appropriately.

Quantification and characterization of the environmental impact of sea bream and sea bass production in Italy

Quantification and characterization of the environmental impact of sea bream and sea bass production in Italy

Out-of-season spawning of largemouth bass in a controllable recirculating system.

Largemouth bass (LMB) production exceeded 0.7 million tons in 2021 and has become one of the most important freshwater aquaculture species in China. The stable and fixed culture cycle led to regular and drastic price fluctuation during the past decade. Strong price fluctuation provides opportunities and challenges for the LMB industry, and out-of-season spawning (OSS) and culture will provide technical support for the opportunities. To induce OSS at a low cost, we established a controllable recirculating system that allows precise thermo-photoperiod manipulation. In the system, four experimental groups were assigned, 18NP (18°C overwintering water temperature, natural photoperiod), 18CP (18°C overwintering water temperature, controlled photoperiod), 16CP (16°C overwintering water temperature, controlled photoperiod), and NTNP (natural water temperature and natural photoperiod), to determine the effects of chilling temperature and photoperiod on spawning performance. OSS was observed in all the experimental groups without significant differences, except NTNP. The manipulated broodstock can re-spawn 3months later in the next spring in advance. Further analysis of the volume percentage of different stages of oocytes provides a base for excellent regression between the volume percentage of the primary growth stage, cortical alveoli stage, vitellogenesis/maturation stage, and gonadal development/maturation. The results suggest that the volume percentage of oocytes is a better indicator of gonadal development and maturation than the gonadosomatic index. We also found that LMB prefers palm fiber as a spawning nest over gravel. The findings of this work provide important technique guidance for practical OSS of the LMB aquaculture industry and standardization of ovary development and maturation in fish with asynchronous developmental oocytes.

Changes in the microbiota of a vacuum-packed cooked bass product and the effects of cobalt irradiation on its quality during storage

This study investigates changes in the microbiota of vacuum-packed cooked bass (Micropterus salmoides), including the effects of different doses of 60Co-γ irradiation (0, 1, 3, and 5 kGy) on muscle quality, during storage at 4 °C (0–15 days). Analyses for other indicators like the total bacterial colony counts and myofibrillar protein concentration were carried out. 16SrDNA high-throughput sequencing results showed that Stenotrophomonas maltophilia had the highest relative abundance in bass after storage. Additionally, the total bacterial colony counts and total volatile basic nitrogen (TVB-N) content of the irradiated samples were within the standard limits after day 15. During 0–6 days of storage, 3 kGy irradiation increased the myofibrillar protein concentration and the water-holding capacity of the fish compared with other doses. However, 3 kGy irradiation had less influence on the surface hydrophobicity of myofibrillar proteins than 5 kGy irradiation. Overall, Stenotrophomonas maltophilia was the dominant spoilage bacteria in bass, and 3 kGy irradiation treatment effectively inhibited microbial proliferation and muscle quality deterioration during storage at 4 °C. Moreover, the optimal storage time for bass products after 3 kGy irradiation treatment was 6 days. This provides a basis for improving bass quality during storage and promoting the application of irradiation technology.

HEALTH RISK ASSESSMENT OF ARSENIC CONTAMINATION FROM THE CONSUMPTION OF COMMERCIALLY IMPORTANT EUROPEAN SEA BASS (Dicentrarchus labrax L., 1758)

Sea bass (Dicentrarchus labrax L., 1758) production in Turkey has increased significantly in recent years, especially for export to EU countries. This study determined inorganic arsenic (iAs) levels by measuring total arsenic levels (AsT) in muscle tissues sampled from sea bass fished and farmed (both in earthen ponds and sea cages) in Güllük Bay within the borders of Muğla province. The study also conducted a risk assessment of sea bass consumption for consumer health. For this aim, fish muscle tissues were mineralized with microwave digestion before total arsenic concentrations were measured using inductively coupled plasma mass spectroscopy (ICP-MS). The highest mean arsenic levels were detected in sea bass cultured in earthen ponds (0.38 mg kg-1) while levels in both sea bass cultured off-shore and wild sea bass were 0.26 mg kg-1. According to the risk assessments based on estimated daily intake (EDI), target hazard quotient (THQ), carcinogenic risk (CR), and lifetime cancer risk (TR), it was revealed that eating sea bass did not damage human health.

Discrimination between Wild and Farmed Sea Bass by Using New Spectrometry and Spectroscopy Methods.

European sea bass (Dicentrarchus labrax L.) is one of the most economically important fish species in the Mediterranean Sea area. Despite strict requirements regarding indications of production method (wild/farmed), incorrect labelling of sea bass is a practice still frequently detected. The aim of this study was to evaluate the capabilities of two techniques, Near-InfraRed (NIR) spectroscopy and mass spectrometry, to discriminate sea bass according to the production method. Two categories were discriminated based on the docosahexaenoic and arachidonic fatty acid ratio by using a Direct Sample Analysis (DSA) system integrated with a time-of-flight (TOF) mass spectrometer. The cut-off value of 3.42, of fatty acid ratio, was able to discriminate between the two types of fish with sensitivity and specificity of 100%. It was possible to classify fish production by using multivariate analysis with portable NIR. The results achieved by the developed validation models suggest that this approach is able to distinguish the two product categories with high sensitivity (100%) and specificity (90%). The results obtained from this study highlight the potential application of two easy, fast, and accurate screening methods to detect fraud in commercial sea bass production.

Toward Systematic Breeding of Asian Sea Bass, Lates calcarifer (Bloch, 1790), in Malaysia: Status, Challenges and Prospects for Future Development

Asian sea bass, Lates calcarifer (Bloch, 1790), is one of the most farmed marine fish in Malaysia since the 1970s and is predominantly cultured at present. Although it has been farmed for some time, there is no systematic breeding programme in place. Local hatcheries rely heavily on wild and imported broodstock. However, imported stocks do not guarantee improved quality and even increase the chances of introducing pathogens into the country. Availability of superior breeding stocks, efficient dissemination and control of seed production could greatly assist in increasing Asian sea bass production. This paper presents the status of Asian sea bass production, its culture history in Malaysia and the current broodstock development programme implemented by the Fisheries Research Institute, particularly in the 11th Malaysia Plan from 2015 to 2020. In brief, broodstock from Malaysia, Thailand and Indonesia were used as base population and were mated using full diallel method to produce cohorts. Three pairs of the selected broodstock were used for each cross and spawning performance was evaluated. The growth performances of the first generation (F1) offsprings were assessed in different culture systems. Physico-chemical water quality parameters such as dissolved oxygen, temperature, pH and salinity were maintained at optimal levels during all stages of the experiment. Results indicate that the growth performance of F1 improved by more than 60 % in terms of weight gain compared with the base population. The project demonstrated the benefits of using selective breeding to enhance the production of Asian sea bass.

Effective and Low-Maintenance IMTA System as Effluent Treatment Unit for Promoting Sustainability in Coastal Aquaculture

Integrated multitrophic aquaculture (IMTA) is a versatile technology emerging as an ecological and sustainable solution for traditional monoculture aquacultures in terms of effluent treatment. Nevertheless, IMTA is still poorly applied in aquaculture industry due to, among other reasons, the lack of effective, low-investment and low-maintenance solutions. In this study, one has developed a practical and low maintenance IMTA-pilot system, settled in a semi-intensive coastal aquaculture. The optimisation and performance of the system was validated using Ulva spp., a macroalgae that naturally grows in the fishponds of the local aquaculture. Several cultivation experiments were performed at lab-scale and in the IMTA-pilot system, in static mode. The specific growth rate (SGR), yield, nutrient removal, N and C enrichment, protein and pigment content were monitored. Ulva spp. successfully thrived in effluent from the fish species sea bream (Sparus aurata) and sea bass (Dicentrarchus labrax) production tanks and significantly reduced inorganic nutrient load in the effluent, particularly, NH4+, PO43− and NO3−. The enrichment of nitrogen in Ulva spp.’s tissues indicated nitrogen assimilation by the algae, though, the cultivated Ulva spp. showed lower amounts of protein and pigments in comparison to the wild type. This study indicates that the designed IMTA-pilot system is an efficient solution for fish effluent treatment and Ulva spp., a suitable effluent remediator.

ANALYSIS OF THE TECHNICAL EFFICIENCY OF EUROPEAN SEA BASS FARMS IN TURKEY: A STOCHASTIC FRONTIER PRODUCTION FUNCTION APPROACH

This study’s main objective was to estimate sea bass farms’ technical efficiency and determine the factors affecting production inefficiency using the stochastic frontier approach. The data were collected using questionnaires from 71 farms in 2017. The total sea bass production cost was calculated 5.35 $ kg-1, income 5.65 $ kg-1, gross profit 0.30 $ kg-1. The proportion of variable costs (84.25%) in total costs was higher than the fixed costs (15.75%). The feed cost (57.56%) was the influential primary variable on the total costs, and the benefit-cost ratio was 1.06. The results indicated that seabass farms’ technical efficiency varied between 0.67 to 1.00, and the average was 0.82. The efficiency scores meant the farms could achieve the same production amount by reducing inputs by 18%. One per cent increase in resale value, feed amount, and fingerling amount, increase sea bass production by 0.4%, 0.4%, and 0.2%, respectively. Fish loss rates and subsidies were influential on inefficiency. It would be beneficial to minimize risk factors such as fish loss rates and carry out political and educational activities to improve farms’ infrastructure in breeding and marketing. As a result, policymakers should also include the effective use of production factors in the design of aquaculture subsidy policies.

Hydroacoustics for density and biomass estimations in aquaculture ponds

The use of hydroacoustics is currently being studied and developed as a promising non-intrusive methodology to monitor and manage fish stocks in aquaculture farms. The main objective of this study was to develop an acoustic method for the estimation of fish density and biomass in inland aquaculture farms and test the accuracy and precision of the estimates with real data provided by the company. The study was conducted in sea bass (Dicentrarchus labrax) production ponds located in Seville (Southern Spain). A Simrad EK60 echosounder with two split-beam circular transducers operating simultaneously at 200 kHz was used for hydroacoustic surveys. Two different hydroacoustic designs were considered: central trajectories and zigzag trajectories. The accuracy and precision of the estimates were examined in order to select the best sampling design. Due to a non-homogeneous fish distribution in the pond caused by the avoidance behaviour, as a response to the sampling disturbance presented by fish, acoustic density and biomass were corrected by applying sampling theory according to the probability of fish detection. When density and biomass were corrected, the estimates became highly accurate and precise with respect to real data, which confirms that the proposed method is adequate. Similarly, acoustic estimates of fish weight were highly in agreement with real data, due to the use of specific equations developed “in situ” for the study. Although no significant differences were recorded in the density and biomass estimates with regard to the trajectory used (central vs. zigzag), it was observed that the most accurate agreement and precision were always obtained in central trajectories. Therefore, central design is proposed as the most appropriate design for hydroacoustic measurements in inland ponds. The results obtained in this study provide estimates of density and biomass that accurately match the real data, supporting the use of hydroacoustics as a potentially valid tool to manage inland aquaculture farms.

Assessing Environmental Impacts of Sea Bass Cage Farms in Greece and Albania Using Life Cycle Assessment

Life-cycle assessment (LCA) is increasingly used in aquaculture studies to quantitatively assess materials, energy flows and impacts of a production system and to evaluate the environmental performance of products and services. The application of LCA to sea bass production in two marine farms located in Greece and Albania demonstrated that feed and accordingly feed conversion ratio, followed by fry were the two predominant factors mostly affecting the eighteen ecological impact categories assessed. In particular, for the Greek farm, feed affected all but one of the impact categories from 76.5 to 99.9%, reflecting the relation of fish feed not only to resource use, but also to impacts during processing, transportation and to its distribution to the farmed stocks. The role of feed was also reflected on its share (90.6%) in the ‘global warming’ indicator. Fry production resulted in a major contribution (99.0%) to the ‘water consumption’ impact category, which is related to the hatchery operation. Concerning the Albanian farm, the impact of fish feed was even more pronounced in most of the ecological indicators, due to the absence of motorised equipment. It is concluded that feeding management and initiatives to improve the cost and the environmental impact in both counties could result in immediate improvements of the ecological and economical outcomes of the mariculture industry in the region. Further benefits are also expected for the ecological sustainability and economic viability of the sector, as consumers are exhibiting interest in environmental awareness and eco-labelling.

Species-specific preferences drive the differential effects of lake factors on fish production

As the global human population grows, it remains a top priority for communities, managers, policymakers, and stakeholders to maintain healthy, sustainable, and productive fisheries under continued global change. Here we used a dataset consisting of fish and lake characteristics for 536 lakes across Ontario, Canada, to test whether multiple climate, human, and biological factors differentially affect fish production (i.e., population biomass per hectare per year). We tested the hypothesis that temperature is the key driver of fisheries production by testing for the effects of multiple factors on the production of three top predatory fish species: cold-water lake trout (Salvelinus namaycush), cool-water walleye (Sander vitreus), and warm-water smallmouth bass (Micropterus dolomieu). Using boosted regression tree analyses, we found that lake trout production was most influenced by the volume of hypolimnetic habitat, walleye production was related to other climatic variables, and smallmouth bass production was most influenced by sampling day of the year followed by Secchi depth. Our results suggest that current fish production models — that only include temperature and body size — may oversimplify important ecological complexities and thus misinform management decisions because species respond differently to environmental drivers.

Volitional tank spawning of domestic striped bass (Morone saxatilis) using human chorionic gonadotropin (hCG) and gonadotropin releasing hormone analogue (GnRHa)- induced ‘pace-setting’ females

Seventy-one tank spawning trials were conducted to evaluate the efficacy of exogenous hormone compounds and a novel “pace-set” strategy for inducing volitional tank spawning behavior in 5th generation domestic striped bass. Female fish (4.74 ± 0.73 kg; mean ± standard deviation) were treated with human chorionic gonadotropin (hCG; 29 trials), gonadotropin releasing hormone analog (GnRHa; 39 trials) or received no hormone treatment (control; 3 trials). Spawning trials were conducted using single females placed in spawning tanks with two (12 trials) or three (38 trials) males or with paired females placed in spawning tanks with three (4 trials) males. Significant differences in egg production, fry production, hatching rate, and fry/kg female body weight were generally not observed between exogenous hormone treatment groups (alpha = 0.05), with the exception of egg production differing between paired females spawning with three males (Student's t-test, p = 0.0255). However, a trend suggesting that increasing the number of males or females within the tanks improves yield of larvae (fry/kg female body weight) was observed. The untreated control females failed to spawn within 7 days. The pace-set spawning was conducted whereby one female treated with either hCG (7 trials) or GnRHa (7 trials) was placed in a spawning tank with one untreated female and multiple males. The results of these trials show for the first time that a hormone-induced female striped bass can be used to stimulate successful volitional spawning of an untreated female in the same tank with fry/kg female body weight production similar to that of hormone-treated fish. Microsatellite-based parentage of select tank spawns and four additional trials conducted with an increased number of males (19 trials total) showed that female striped bass typically spawn with at least two males; a single pair mating was only observed for one spawning trial. These data allowed for the determination of effective broodstock size (Nb) of each tank spawning trial at between 2.00 and 5.60 when considering all male contributions. The Nb generally increased as the number of males and female fish in the tank increased (from 2.53 for one female and two males to 5.52 for two females and six males). These results indicate that domestic striped bass are promiscuous and will generally reproduce in captivity using tank spawning procedures that allow for a high level of genetic diversity to be retained among the offspring. The pace-set method reduces hormone use and may be applied to commercial striped bass production as well as captive spawning of other fish species.

Assessment of a high protein distillers dried grain (HP-DDG) augmented with phytase in diets for European sea bass, Dicentrarchus labrax fingerlings on growth performance, haematological status, immune response and related gut and liver histology

Inclusion of high levels of plant protein ingredients in fish feeds induces the presence of undesirable compounds such as Anti-Nutritional Factors, including non-starch polysaccharides and phytates. The present study evaluated the effect of partial replacement of dietary soybean meal by a high protein distillers dried grains (HP-DDG) a co-product of corn based ethanol production. We evaluated HP-DDG in experimental diets with a supplemented commercial phytase on growth performance, physiological parameters and histological changes of the intestine and liver of European sea bass, Dicentrarchus labrax fingerlings. The experiment was conducted for six weeks. A total of 240 D. labrax fingerlings was randomly divided to four experimental treatments (each in triplicates groups) and fed to apparent satiation six days per week for a six weeks’ period. Four dietary treatments: containing 0, 30, 40 and 50% HP-DDG supplemented with enzyme phytase 0.5g kg-1 diet respectively, were tested. The results showed that growth performance and feed utilization efficiency of sea bass was significantly higher (P≤0.05) with increasing levels of HP-DDG-and phytase supplementation. Superior phosphorous utilization was also observed with respect to whole body retention for each incremental level of HP-DDG inclusion. Hematology and serum biochemistry (hemoglobin (Hb), red blood cells (RBCs), white blood cells (WBCs) and humoral immune parameters including total protein, globulin, cholesterol, lysozyme activity and total antioxidant capacity (TAC) were improved (P≤0.05) in fish fed diets with increased levels of HP-DDG and supplemented phytase. The findings suggest that the use of HP-DDG supplemented with phytase in sea bass diets enhanced growth, physiological and immunological responses, and evidenced a cost benefit advantage for European sea bass production compared to the use of a diet without either HP-DDG or phytase incorporation.

Evaluation of co-fermented apple-pomace, molasses and formic acid generated sardine based fish silages as fishmeal substitutes in diets for juvenile European sea bass (Dicentrachus labrax) production

Due to a need to address the potential of converting overfished sardines in North Africa and Middle East into a stable product, whole sardines were ensiled using different methods, and subsequently tested in a feeding trial and sequential digestibility assessment performed on sea bass, an important farmed fish of this region.Four isonitrogenous and isocaloric experimental diets were formulated for juvenile European sea bass replacing the fish meal protein component of a control diet with an apple pomace fermented fish silage (APFS); molasses fish silage (MFS) and formic acid silages (FAFS). Feeding sea bass with fish silage based diets generated similar or lower growth performance, feed utilization, protein efficiency and retention compared to the fish meal based diet. Hematological parameters were also measured at the end of the feeding trial. However, a significant difference (P < .05) was observed between the FAFS fed group and fermented fish silage treatments except for the APFS group with respect to leukocyte levels. Formic acid silage fed sea bass, showed more complicated mucosal fold features with greater depth, regularity and overall surface area (gut perimeter ratio) being significantly different (P < .05) compared to the control group. The apple pomace silage resulted in fish having the lower gut perimeter ratio.Scanning electron micrographs (SEM) of the distal intestine revealed that sea bass fed with all experimental diets showed no evidence of mucosal epithelial damage with all fish having healthy and regular shaped enterocytes lining the posterior intestine.However the microvilli gut enterocyte layer of sea bass fed apple pomace fish silage appeared thinner compared to all other treatment groups of sea bass. The study showed no evidence of any impaired general hematological changes indicative of health status of sea bass at the end of the trial period.In a consecutive digestibility evaluation, the apparent digestibility coefficient of dry matter (ADCdry matter) of the experimental diets was found to be relatively lower than the control group. However, the apparent digestibility coefficients for protein (ADCprotein) and energy (ADCenergy) were deemed acceptable for all silages tested.The overall findings of this study indicate that fish silage produced from organic acids or by fermentation with carbohydrate sources and lactic acid bacteria were an effective partial replacement of fish meal in aquaculture feeds. We show that this has potential for applications in diet formulations for European sea bass being an important farmed Mediterranean marine species.

Availability and Timing of Fathead Minnow Supplementation Influence Largemouth Bass Survival and Production in Rearing Ponds

Adjustments to rearing practices should be justified with increases in production, stocking success, or angler satisfaction. Largemouth bass (Micropterus salmoides) production was assessed between hatchery ponds where fish were restricted to an invertebrate diet or received supplemental fathead minnow (Pimephales promelas) forage during 2015. At harvest, age-0 bass yield was 4.5 times greater and average fish length was 38 mm longer, in the pond that received fathead minnow. In 2016, a second study evaluated the timing of minnow supplementation that included earlier stockings of small fathead minnow (30 mm) minnows. With earlier supplementation, bass yield was 2.3 times greater and fish averaged 14 mm longer at harvest. Bass survival was approximately 38% higher during 2015 when supplementation occurred and 25% higher during 2016 when minnow supplementation began earlier. Our findings show invertebrate forage was probably limiting bass production in hatchery ponds and supplementing with appropriately-sized fathead minnows increased age-0, largemouth bass production.