Journal of The World Aquaculture Society最新文献

In the pond culture production process, culture patterns and conditions have important impacts on the feeding, growth, metabolism, behavior, physiology, biochemistry, and immune responses of aquatic animals. These interact with the ecological environment to jointly determine the production outcome of pond culture. Both of Acanthopagrus schlegeli and Apostichopus japonicus are high economic value mariculture animals. This study investigated the effects of pond monoculture and integrated culture patterns as well as different culture densities, water depths, and background colors used in the integrated culture pattern on the growth performance, survival rate (SR), and biochemical composition of A. schlegeli and A. japonicus. Finally, the suitable conditions for integrated pond culture of A. schlegeli and A. japonicus were obtained. Under the patterns AB (integrated culture of A. schlegeli and A. japonicus), A (A. schlegeli monoculture), and B (A. japonicus monoculture), differences in final body weight (W_t-final), specific daily growth rate (SGR), secondary production (P), and SR were not significant (p > 0.05). However, the overall growth of cultured animals in AB was better than in A or B. The differences in proximate composition between A. schlegeli and A. japonicus were not significant among different culture patterns (p > 0.05), nor were the differences in superoxide dismutase (SOD) activity of A. schlegeli between AB and A (p > 0.05). However, the SOD activity of A. japonicus in AB was significantly higher than in B (p < 0.05). Based on the statistical analysis and actual production situation, density bc (A. schlegeli: 36 ind. m⁻³, A. japonicus: 5 ind. cage⁻¹) would be the most suitable combination for integrated culture of A. schlegeli and A. japonicus. The optimal water depth for integrated culture of A. schlegeli and A. japonicus would be 2 m, and white would be the best background color. Our study results provide useful scientific data for the pond culture production and management of A. schlegeli and A. japonicus.

Increased vitellogenin availability for deposition in oocytes can improve the success of embryonal growth and development and the quality of catfish larvae and juveniles produced. This study aimed to evaluate the effects of katuk extract, turmeric powder, and vitamin C supplementations for eight weeks before mating on the reproductive success of catfish. The results showed that serum estradiol-17β and vitellogenin concentrations, fecundity, egg diameter and weight, and hatching rate were consistently highest in the catfish supplemented with a combination treatment, and were lowest in the control. The highest egg yolk volume in larvae was observed in the catfish supplemented with the combination treatment (1.53 ± 0.13), and the lowest volume was found in the control (0.97 ± 0.03). The hatched larvae were maintained for three days without feeding, and the results showed that the combination treatment had the highest survival rates (52.00 ± 6.93) and the lowest in the control (13.33 ± 6.11). At the age of 30 days, the highest absolute growth and survival rate was found in larvae produced by the combination treatment, and the lowest was found in the control. It was concluded that supplementation with a combination treatment increased estrogen and vitellogenin synthesis by the hepatocytes, thus increasing vitellogenin deposition in the egg and increasing follicle recruitment to increase fecundity. The results of the present experiment confirmed that improved vitellogenin synthesis and deposition in the ovulated eggs improved fecundity and egg quality, eventually increasing the numbers and quality of larvae and juveniles produced.

In the Yucatán Peninsula, México, the red eucheumatoid algae Eucheumatopsis isiformis has been proposed as a candidate for mariculture to obtain carrageenan, a sulfated polysaccharide widely used as a food thickener and stabilizer. As a part of the efforts to develop tropical seaweed cultivation in the region, we studied the photophysiological and growth responses to different light and temperature levels of two morphotypes with contrasting forms and thicknesses, to determine the optimal levels for large-scale cultivation. First, in laboratory experiments, we quantified changes in photosynthesis and respiration rates, pigment content, and growth rate under low-, medium-, and high-light intensities. In a second approach, we scaled up these experiments in a mesocosm system using the optimal light levels identified to test the response to short-term increases in temperature according to seasonal variation. This study showed how irradiance modulated all responses; pigmentation was reduced while photosynthetic capacity, saturation irradiance, and growth increased under high light in both morphs. The thinner morphology (M1) showed the highest photosynthetic capacity and a linear response to light (LL<ML<HL), standing as a better candidate for cultivation. Temperature experiments in M1 showed that light acclimation modulates photosynthesis responses; it was positively affected under low light, while at high light it was not. Hence, light conditions driven by seasonal changes play an important role in the performance of E. isiformis, and special attention should be focused on the vertical cultivation system, which can regulate the incident light to maximize outcomes. The improvement and development of E. isiformis cultures are feasible and could provide an alternative industry for local fishermen, but more information is needed, particularly related to temperature and nutrient availability.

In the field of freshwater aquaculture, water quality significantly impacts the aquaculture products. Fluctuations in water quality can hinder the growth of cultured organisms, lead to frequent diseases, and even cause mass mortality. Therefore, accurately predicting water quality is crucial. To reduce the error rate that may occur when using traditional long short-term memory networks (LSTM) models for water quality prediction, this article proposes a Pearson-LSTM-AM water quality prediction model. Initially, the Pearson correlation test algorithm is used for the input feature selection, and then an attention mechanism is integrated to enhance the LSTM neural network's ability to learn the key features, specifically for predicting the dissolved oxygen (DO) indicator of water quality. Experimental results demonstrate that the proposed method significantly improves upon the Pearson-LSTM model and the LSTM model in terms of root mean square error (RMSE), mean absolute percentage error (MAPE), mean absolute error (MAE), and the coefficient of determination (R²) metrics.

The aim of this case study was to investigate and describe water quality and growth performance of Penaeus vannamei produced in a super-intensive biofloc system (BFT) under diverse water conditions (seawater and low-salinity water) in the state of Virginia, USA. Three individual indoor super-intensive grow-out trials were conducted using a stocking density of 500 shrimp m⁻³ at salinities of 23 g L⁻¹ for 70 days (TI), 28 g L⁻¹ for 69 days (TII), and 2 g L⁻¹ for 30 days (TIII). Key water quality management strategies included: (TI) BFT system; (TII) BFT system and probiotic; (TIII) BFT system, probiotic, water reuse, and artificial substrate. TII exhibited the highest mean total ammonia nitrogen (TAN) concentration (2.60 mg L⁻¹), and the greatest variation in TAN levels, which were controlled from day 35 onward. TAN levels remained relatively stable in TIII. TI exhibited the highest mean nitrite concentration (3.66 mg L⁻¹) and the greatest variation, with a spike that was successfully controlled from day 35 onward. In contrast, nitrite concentrations in TII displayed a continuous upward trend from day 28 without any indication of stabilization. Nitrite concentrations in TIII remained consistently low, never exceeding 0.5 mg L⁻¹ throughout the experiment. Nitrate concentrations exhibited a consistent upward trend across all trials. The final weight of shrimp in TI and TII was 11.03 g and 13.62 g respectively, while in TIII it was 4.86 g. Survival rates were 77.67% in TI, 86.00% in TII, and 87.00% in TIII. Yield values were 4.28, 5.81, and 2.12 kg m⁻³ for TI, TII, and TIII, respectively. Our findings indicated slower nitrification rates in TI and TII compared to TIII. Water reuse, probiotic inoculation, and artificial substrates in TIII resulted in significantly lower and more stable levels of ammonia and nitrite compared to TI and TII, indicating a mature system with improved control for nitrogenous compounds. These findings demonstrate the successful application of integrated BFT strategies, including water reuse, probiotic inoculation, and artificial substrates, in enhancing the super-intensive indoor production of P. vannamei using both seawater and low-salinity water. These results have significant implications for the development of shrimp farming in the state of Virginia, USA.

A type of fermented bile acid (BA) named 170HDa was produced using a biological method, and its impacts on growth performance, metabolism, and intestinal microbes in Chinese perch (Siniperca chuatsi) were investigated. Seven experimental diets were established, including treatment groups supplemented with 0.02%–0.06% 170HDa (GN1-GN5), a positive control diet containing 0.04% commercial BAs (GN6), and a negative control diet without BA supplementation (GN7). The trial lasted for 6 weeks. Results demonstrated significant improvements (p < 0.05) in growth indicators such as final weight (FW), weight gain (WG), specific growth rate (SGR), and feed conversion ratio (FCR) in fish fed diets containing 0.02%–0.04% 170HDa compared to the control groups. Serum biochemical analyses revealed that dietary 170HDa improved lipid metabolism by significantly reducing low-density lipoprotein cholesterol (LDL-C) and amylase (AMS) (p < 0.05). Histopathological examination indicated that 0.02%–0.04% 170HDa-treated fish showed more intact intestinal villi and less inflammatory damage, whereas the control group displayed notable intestinal damage characterized by inflammatory cell infiltration, lysis, and severe vacuolization. Gut microbial diversity was significantly affected by 170HDa treatment, particularly at the phylum (Proteobacteria, Tenericutes, Firmicutes, and Fusobacteria) and genus levels. Moreover, the highest activities of acid and alkaline phosphatase appeared in the GN3 group. Meanwhile, elevated levels of IL-1β, TNFα and NF-kB p65 were found in the 170HDa-treated groups. These findings suggest that dietary 170HDa at a concentration of 0.02%–0.04% effectively enhanced growth performance, lipid metabolism, and intestine health in Chinese perch, potentially offering an environmentally friendly alternative to chemically extracted BAs.

This study evaluated the benefits of a commercial probiotic, Aqua Fortuna probiotic (AFPB), containing multiple bacterial strains isolated from fish gut microbiota, on the physiological performance of white-leg shrimp (Litopenaeus vannamei). Juvenile shrimp were fed varying doses of AFPB (0.5%, 1%, 2%, and 5%) during their maturation period, and their growth indices, including weight, growth rate, feed conversion ratio, and survival rate, were measured biweekly. In addition, gene expression levels of growth factors (IGF1, IGFBP, VEGF1–3) and immune-related markers (antimicrobial peptides: penaeidin-3a, crustin, lysozyme; pattern recognition receptors: β-1,3-glucan binding protein, lipopolysaccharide, and β-glucan binding protein; detoxification enzymes: SOD, prophenoloxidase, hemocyanin) were analyzed in digestive tissues via qPCR on week 8. Furthermore, L. vannamei was challenged with Vibrio parahaemolyticus, and post-challenge survival rates were monitored. The results revealed that AFPB supplementation significantly enhanced the growth performance of L. vannamei. Notably, 1% of AFPB yielded the most significant improvements in the final weights, specific growth rates, and better survival rates. During the lethal challenge with V. parahaemolyticus, groups treated with 5% and 2% AFPB showed higher survival rates at 4 and 8 weeks, respectively. Gene expression analyses showed that 1% AFPB upregulated penaeidin-3a, crustin, lysozyme, prophenoloxidase, superoxide dismutase, and β-1, 3 glucans binding protein in digestive tissues, whereas 2% AFPB additionally upregulated immune genes like prophenoloxidase and lysozyme. Our findings highlight the role of shrimp microbiota in promoting growth and enhancing disease resistance, providing robust evidence for the use of probiotics as a strategy to improve shrimp cultivation productivity.

SYCP1 and SYCP3 are essential testis-specific genes for centromere pairing during meiosis, as well as for spermatogenesis and fertility in male germ cells. However, it is still unclear regarding the expression patterns in the fertile reciprocal hybrid offspring of Megalobrama amblycephala (blunt snout bream, BSB, 2n = 48) × Culter alburnus (topmouth culter, TC, 2n = 48). This research elucidated the genetic and expression characteristics of SYCP1 and SYCP3 through molecular cloning, sequence alignment, Western blotting, and immunohistochemistry to assess their roles in both hybrids and parents. The findings revealed that SYCP1 and SYCP3 exhibited high homology between M. amblycephala and C. alburnus, with varying degrees of chimerism in the BT and TB hybrids. The expression level of SYCP1 in these hybrids was intermediate between parents, while SYCP3 was more similar to M. amblycephala and significantly different from C. alburnus (p < 0.05). Western blotting confirmed the normal expression of both SYCP1 and SYCP3 proteins in the hybrid offspring. Immunohistochemistry verified the significant presence of these proteins in the testes of mature hybrids. These findings suggested that BT and TB hybrids retained the stability of the SYCP1 and SYCP3 genes inherited from their heterozygous parental origins, supporting independent protein expression despite slight variations in the CDS structure. Our results demonstrate that the normal expression of key meiotic genes plays an important role in overcoming reproductive barriers in distant hybridization, which is of great significance for genetic breeding in fish.

The aquaculture industry faces several global challenges, particularly concerning the environmental impacts of effluent discharge and the spread of viral and bacterial diseases. Diverse strategies have been implemented with different degrees of success. These include recirculating aquaculture systems (RAS, BioRAS), integrated multitrophic aquaculture (IMTA, Aquaponics and FlocPonics), and the use of microbial aggregates on submerged floating substrates (biofloc technology or BFT). Over the past two decades, BFT has emerged as a viable alternative for producing food from aquatic organisms, primarily due to its ability to recycle waste and significantly reduce water usage. Despite this, the technology is not yet used on a large scale around the world. Examples of commercial microbial-based systems are found in Vietnam using chemoautotrophic-based BFT and in Thailand using heterotrophic-based BFT (Emerenciano et al., 2022). The effectiveness of this technology has yet to be fully established in regions experiencing extreme environmental fluctuations, such as variations in temperature and salinity. This editorial provides insights into how BFT can be adapted and implemented under such conditions, including recommendations for assembling, managing, and optimizing microbial consortia that are suitable for coping with extreme environmental changes.

Aquaculture is an agro-industry whose contribution to human development has been evident throughout many decades, not only as a food source but also as a generator of foreign exchange, employment, and social welfare. It has even been considered a mitigator of overexploitation by fishing. However, despite its numerous benefits, diverse environmental impacts have been associated with the activity, primarily due to the discharge of effluents containing high concentrations of nitrogenous compounds, organic matter, antibiotics, and various chemical compounds. These effluents could degrade the environment, leading to unfavorable conditions for the surrounding ecosystems' flora, fauna, and microbiota (Martinez-Porchas & Martinez-Cordova, 2012).

BFT was developed in the 1970s but emerged strongly at the beginning of the 2000s as a solid strategy to overcome some of these problems. Based on the bioaugmentation of heterotrophic bacteria through bio preparation of the systems conditions, including a high carbon: nitrogen ratio, pond lining, reduced light intensity, high alkalinity, proper aeration, and solids removal protocols, the system produces edible microbial biomass for the cultured animals while recycling generated wastes (Khanjani et al., 2024). Despite this strategy gaining popularity and solving several aquaculture drawbacks, it was conceived to perform under optimal conditions in which regulating environmental variations is achievable. However, this is not the case for large farms, particularly those in arid, dry climates. In these regions, high temper

In this feeding trial, the replacement of fishmeal (FM) with peanut meal (PM) was examined to assess its effects on growth performance, body composition, digestibility, and immunity in cultured juvenile beluga (Huso huso; initial weight: 132 ± 8.5 g). Four experimental diets were tested (3 replicates; 12 fish each), including a control diet (0% replacement) and diets with 10%, 20%, and 30% PM replacement levels, fed to fish over a 56-day period. The results showed that fish fed a diet with 10% PM replacement achieved the highest final weight, weight gain, and specific growth rate, as well as the lowest feed conversion ratio (FCR). As PM replacement levels increased, muscle protein content increased, while lipid content decreased (p < 0.05). Analysis of muscle fatty acids indicated that with higher replacement levels, saturated fatty acids (SFA) and polyunsaturated fatty acids (PUFAs) increased (p < 0.05), while highly unsaturated fatty acids (HUFAs) decreased (p < 0.05). Additionally, the 10% replacement treatment exhibited the highest levels of essential amino acids in muscle tissue (p < 0.05), along with the greatest digestibility of dry matter and crude protein (p < 0.05). Immune parameters, specifically lysozyme and ACH50, showed significant increases compared to the control as PM replacement levels rose (p < 0.05). Based on the results, it can be concluded that partial replacement of FM with PM at a level of around 10% can enhance growth performance, nutrient digestibility, and immune response in Juvenile beluga.