Journal of The World Aquaculture Society最新文献

This study evaluated POET CFP, a corn-fermented protein derived from dry-mill bioethanol production, as a potential candidate for use in European seabass aquafeeds. The apparent digestibility coefficients (ADC) of POET CFP were evaluated and compared to soybean meal. The ADC of POET CFP protein was higher than that of soybean meal (92.7% vs. 83.9%), and the neutral detergent fiber (NDF) of POET CFP was partially digested (26%), while that of soybean meal was completely undigestible. However, the ADC of energy was similar between the two feedstuffs (70%). Two growth trials were performed to evaluate the effect on growth performance and feed utilization of European seabass for total or partial replacement of corn gluten meal (CGM) (Trial 1) or CGM and soybean meal (CGM + SBM) (trial 2) with POET CFP. For that purpose, a practical diet with 48% protein and 18% lipids was formulated to include 20% fish meal, 15% CGM, and 15% SBM (control diet). For trial 1, four diets similar to the control were formulated with POET CFP replacing CGM at 25%, 50%, 75%, and 100%. For trial 2, three other diets similar to the control were formulated, but POET CFP replaced CGM + SBM at 33%, 66%, and 100%. Triplicate groups of European seabass juveniles with 26 g were fed these diets for 85 days. Results of Trial 1 showed that total dietary replacement of CGM with CFP did not affect growth performance, feed intake, feed utilization, and whole-body composition. N retention (% N intake) was also unaffected, but energy retention (% energy intake) linearly increased with dietary CFP inclusion. Further, the histomorphological appearance of the posterior intestine was unaffected by dietary CFP inclusion. Results of trial 2 showed that total dietary replacement of CGM + SBM with CFP did not affect growth performance, feed intake, feed utilization, and N and energy retention (% intake). However, polynomial contrasts showed a significant linear trend for increased growth performance and feed efficiency with the dietary inclusion of CFP. Whole-body dry matter and lipid content linearly decreased with the dietary increase of CFP. No differences were observed between groups in the histomorphological appearance of the distal intestine. This study showed that CFP could completely replace CGM and SBM in diets for European seabass juveniles without affecting growth performance and feed utilization or adversely affecting posterior intestine morphology.

The tropical sea cucumber, Holothuria scabra, plays an important economic and ecological role. Aquaculture of this species has been developing rapidly, and an increasingly effective and efficient system for juvenile production is required. Nursery is a crucial process, as it involves the transition of rearing methods from indoor hatcheries to outdoor environments. This study determined the influence of various nursery sites within earthen pond systems on the growth and survival of juvenile H. scabra. Juvenile H. scabra with a mean wet weight of 1 g (n = 50) were held in replicate floating hapa units over 84 days across four nursery sites: reservoir pond (RP), stirred pond (SP), non-stirred pond (NSP), and main inlet sluice (MIS). Sea cucumbers in MIS exhibited significantly higher weight gain (6.95 ± 0.90 g), growth rate (0.08 ± 0.01 g day⁻¹), and specific growth rate (2.36 ± 0.15% day⁻¹) than all other treatments. Survival did not differ significantly among treatments, ranging from 64.00% ± 2.37% to 74.80% ± 5.82%. The MIS exhibited the highest growth rate for juvenile H. scabra, presumably supported by favorable environmental conditions and effective water exchange. These findings highlight the importance of water circulation and nursery site selection indicating that strategically positioning hapa units close to inlet zones may improve juvenile performance in commercial aquaculture.

Small indigenous fish species, such as mola carplet (Amblypharyngodon mola), play a crucial role in the diets of fish-dependent populations in India due to their rich micronutrient content. Recognized as a key species for promoting nutrition-sensitive aquaculture, mola has recently been successfully bred in hatcheries using standardized induced breeding and mass seed production protocols. This study assesses the economic viability of integrating mola seed production into an existing carp hatchery in Odisha, India. A comprehensive financial analysis, including cost-return assessment, bankability, economic performance, break-even analysis, and sensitivity testing, was conducted. The proposed model has a production capacity of 1 million seeds per cycle, with 24 cycles annually. The total investment required is INR 4,12,932 ($4975), comprising capital expenses of INR 2,56,650 ($3092) and annual operational costs of INR 1,56,282 ($1883) considering the loan component. The business model demonstrates strong profitability, with an operational profit margin of 53.57% at a selling price of INR 1000 ($12) per 100,000 hatchlings. The break-even point is achieved at 17 production cycles per year and INR 885 ($10) of per unit of seeds price. Financial indicators confirm high viability, with a benefit–cost ratio of 1.67, a net present value of INR 2,28,233 ($2750), and an internal rate of return of 32.94%. The model is also bankable, evidenced by a debt service coverage ratio of 1.63, and remains profitable under various sensitivity scenarios. These findings highlight the potential for integrating mola seed production into existing carp hatcheries, offering a scalable and sustainable approach to strengthening small indigenous fish farming and advancing nutrition-sensitive aquaculture in India.

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.