Journal of The World Aquaculture Society最新文献

Aquaculture is one of the most prominent sectors of Bangladesh regarding nutrition, livelihood, and revenues. Although this nation has made promising improvements in aquaculture, several existing and imminent challenges can disrupt further development. Until now, no studies have extensively reviewed the existing aquaculture practices of this nation. Thus, this article elucidates the prospects, production, and problems of common aquaculture practices for the establishment of sustainable aquaculture in Bangladesh. The culture units are mainly natural bodies of water including earthen ponds, seasonal floodplains, baor, and gher. Although pond farming is the oldest and most dominant practice in this nation, the use of pen and cage cultures has also been intensified in the last decade. Regarding farmed fish species, indigenous major carps, exotic carps, tilapia, pangas catfish, and climbing perch are the major runners. Among crustaceans, giant freshwater prawns and tiger shrimp are the leading farmed species. Mud crab, biofloc, and seaweed farming are a growing focus that can evolve as artisanal and commercial-scale farming practices in the near future. Major challenges that are potent enough to impede the establishment of viable aquaculture practices in Bangladesh are inadequate seed production, disease outbreaks, climate change, mediocre management practices, and limited mariculture propagations.

Regulatory changes to the Lacey Act and recent petitions to add aquaculture species in trade to the list of injurious wildlife could lead to prohibitions of interstate movement of live aquatic organisms with the potential for unintended, negative economic consequences. In this analysis, the economic impact of the potential federal prohibition of interstate transport of seven aquaculture species (blue catfish, tilapia, red swamp crawfish, grass carp, koi, guppy, and goldfish) currently in trade was assessed. Total economic impact was estimated to be $452 million (USD) annually, with a loss of 4819 jobs and a loss of $35 million in tax revenue. Effects could potentially occur on the largest sectors of U.S. aquaculture in as many as 80% of U.S. states and result in negative economic effects on as much as 21% of U.S. aquaculture farms.

Methionine (Met) is one of the most limiting essential amino acids in aquafeeds, and different commercial feed-grade Met sources are available for diet supplementation, namely L-Met, DL-Met, and hydroxy-Met (OH-Met). In this work, we compared the bioefficacy of OH-Met and DL-Met as diet supplements for gilthead seabream (Sparus aurata) juveniles reared at normal (22°C) and high (29°C) water temperatures. Two isoproteic (50%) and isolipidic (20%) practical diets (24% fish meal; 6% fish oil) were formulated to contain 1% Met and were supplemented with 0.2% DL-Met (diet DL-Met) or OH-Met (diet OH-Met). The diets were fed to triplicate groups of fish with an initial body weight of 13 g for 78 days. Growth performance and N retention (%) were higher at 29°C. However, feed efficiency, protein efficiency ratio, and hepatic and visceral indexes were higher at 22°C. Hepatic oxidative stress indicators were not affected by dietary Met source. In the muscle, however, oxidative stress index and lipid peroxidation were lower in fish fed the OH-Met diets. Overall, DL-Met and OH-Met proved to be similarly effective as dietary methionine sources for gilthead seabream, while OH-Met seemed to be more effective in reducing oxidative stress in fish reared at high temperatures.

Community-based aquaculture can reduce dependence on natural resources, promote biodiversity conservation, and improve local economies and food security. However, this activity is highly dependent on local conditions regarding natural resources, such as the availability of produced organisms, adequate feeds, and environmental factors. As ectothermic organisms, fish are more susceptible to temperature fluctuations in culture conditions. A set of raw ingredients (e.g., cassava and local beans) produced or available in villages from Cabo Delgado (Mozambique) with nutritional potential for fish feed were selected to produce an experimental diet. The following objectives were defined: (1) evaluate growth performance of tilapia fingerlings fed a diet produced with local ingredients, compared with a commercial-like diet; and (2) evaluate the response to thermal stress (18, 26, and 32°C) by tilapia fingerlings fed with tested diets. Tilapia fed with an experimental diet presented lower growth rates, lower DNA damage, higher neurophysiological, and antioxidant activity, leading to increased oxidative stress. Regarding energy budget, tilapia fed with the experimental diet presented higher protein content at 26°C and lipids at 18°C, leading to greater energy available at these temperatures. Overall, local ingredients can be successfully used as an additional feed source for tilapia production in community-based aquaculture in earthen ponds.

The present work aimed to investigate the impacts of tank color (transparent, light blue, and red), feed pellet types (floating and sinking), and their interaction on the performance and welfare of red hybrid tilapia juveniles with an initial average weight of 19.59 g for a 50 day trial period following a 3 × 2 factorial design. Fish were cultured randomly at a stoking rate of 10 juveniles/100-L tank. Fish were fed 6 days per week at a rate of 4% biomass twice daily. Three replicates were performed for each measurement. A two-way analysis of variance showed that using tanks of different colors (transparent, light blue, and red) has no impact on the growth, feed efficacy, survival rate, and blood composition (except for red blood cells, hematocrit, and triglycerides) of tilapia. Also, pellet types (floating and sinking) showed no significant alterations for the above variables except for glucose and hematocrit levels. Interestingly, the interaction between tank color and pellet type exhibited significant impacts on growth parameters, feed utilization, blood variables, and intestinal enzymes of red hybrid tilapia. Moreover, fish reared in transparent or light blue tanks and fed with floating diets performed the best for all evaluated parameters. Additionally, sinking pellets had better effects when combined with red (dark)-colored tanks.

Offshore aquaculture is a growing industry, but a lack of social acceptance is limiting development, including within the USA. We used the Gulf Coast of Florida, where there has been industry and government interest in development, as a case study to explore offshore aquaculture potential and methods for integrating stakeholder concerns into offshore aquaculture development. We assessed (1) social acceptance of offshore aquaculture in the Florida Gulf Coast using public comments; (2) site suitability for offshore development using social, biological, and technical data; and (3) potential impacts of offshore aquaculture on communities using socioeconomic vulnerability indices. We found that many stakeholders distrust policymakers and industry and have concerns about potential environmental impacts. We created species-specific suitability maps for red drum (Sciaenops ocellatus) and almaco jack (Seriola rivoliana), demonstrating that large areas of the Gulf are suitable for offshore aquaculture development. We show that many coastal and fishing-reliant communities have existing vulnerabilities that aquaculture development could affect, but the public comments did not reflect these. To gain social acceptance, industry and government agencies will need to better incorporate public feedback into planning processes in a meaningful way. Consulting local communities and adapting projects in response to their concerns can help to secure social license for offshore aquaculture.

The efficacy of dietary β-glucan supplementation in golden trevally (Gnathanodon speciosus) was evaluated. The fish were fed five different diets supplemented with 0%, 0.05%, 0.10%, 0.20%, and 0.40% β-glucan for 56 days. After 56 days of culture, survival was the highest when the fish were fed a 0.10% β-glucan diet. Growth rates were higher in fish fed diets supplemented with all β-glucan levels. Lymphocytes increased when the fish were fed a diet supplemented with 0.05% β-glucan, and thrombocytes increased when the fish were fed 0.2% and 0.4% β-glucan-supplemented diets. The total aerobic bacteria count in the gut of golden trevally was higher (p < 0.05) and the total Vibrio counts in the gut of golden trevally were lower (p < 0.05) when the fish were fed any level of β-glucan. Flesh protein content was higher and flesh lipid content was lower when fish were fed β-glucan-supplemented diets at levels greater than 0.1%. When challenged with Streptococcus iniae, fish fed diets containing 0.10% or 0.20% β-glucan exhibited the highest survival rates. The current results suggest that supplementation with 0.05 to 0.2% β-glucan in the diet would be beneficial for the culture of the golden trevally.

In this study, a biofloc technology (BFT) based 90-day feeding trial was performed to estimate the effects of four different dietary protein levels (290, 320, 350 and 380 g protein kg⁻¹ diet; 29P, 32P, 35P, and 38P, respectively) on growth performance, digestive enzyme activity, non-specific immune response, whole-body proximate and fatty acid composition and intestinal microbiota of Farfantepenaeus aztecus. Final weight, weight gain, and specific growth rate improved with protein levels up to 35P per kg of diet, below which decreased significantly. Significant differences were observed in total hemocyte count, acid phosphatase, respiratory burst, glutathione, alkaline phosphatase, and total antioxidant capacity indices of shrimp fed different dietary protein levels. Protease, lipase, and amylase activities of shrimp were also affected by dietary protein levels. Proteobacteria was the most abundant bacteria among the groups. Overall, this study revealed that using 35% dietary protein is optimal in F. aztecus culture under environmentally friendly BFT conditions. Furthermore, these results provide a theoretical basis for future research on the evaluation of functional ingredients in diet for more economical production of F. aztecus at optimal protein levels.

Although hybrid catfish (Ictalurus punctatus × I. furcatus) now constitute about half of the industry production, few studies have assessed comparative growth and survival with other commercially important catfish. Growth assessment is particularly important at moderate to high temperatures because of the direct influence of temperature on ectothermic organisms and the increasing trend of warm to extreme environmental temperatures. Therefore, growth, condition factor, and survival of channel (I. punctatus), blue (I. furcatus), and hybrid catfish were compared following a 10-week growth experiment at moderate (23°C) and high (33°C) temperatures in tanks. It was hypothesized that hybrid catfish would outperform channel and blue catfish in overall growth due of heterosis, and growth of all three fish types would be greater at moderate than high temperatures, which are above the range for optimal channel and blue catfish growth. Channel catfish had the greatest growth and were in better condition compared to blue and hybrid catfish over moderate and high temperatures. All treatments had an average survival over 89% other than blue catfish at 33°C, which had an average survival of 63%. Therefore, these results indicate growth and condition factor in channel, blue, and hybrid catfish diminish at high temperatures, and channel catfish may outgrow blue and hybrid catfish at moderate to high temperatures.

Growth selection in fish is essential for aquaculture; however, long generation times and artificial breeding limitations present challenges for breeding endeavors. The tomato grouper (Cephalopholis sonnerati) is an emerging aquaculture species with a generation cycle of at least 5 to 10 years. Mixed culture of broodstocks and natural mating are commonly employed in hatcheries. To expedite the selection process for tomato grouper, we utilized ISSRseq technology for assisted future growth selection. After 6 months of rearing, we selected 48 individuals, including 24 fast-growing and 24 slow-growing individuals (representing the top and bottom 10% of samples). These samples produced 932 SNPs. Although specific broodstock pairing information is unavailable, our results suggest that these fry likely originated from multiple broodstock exhibiting considerable diversity. Further analysis of genetic relationships among individuals revealed three main clades. One clade contained a higher proportion of faster-growing individuals (80%), while another featured a lower proportion of rapidly growing individuals (28.6%). Through the relatedness network and further exclusion of individuals, the faster-growth clade comprised 92.3% of fast-growing individuals. The faster-growth clade is appropriate for further development into a high-growth strain. Our findings demonstrate that molecular markers can advance population selective breeding to family selection in aquaculture breeding research.