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All‐female stocks of giant freshwater prawn, Macrobrachium rosenbergii, hold immense potential for aquaculture but early sexual maturity might still be a constraint in all‐female prawn farming. The growth performance and gonadal maturation of all‐female M. rosenbergii reared in 1,000 L tanks for 60‐days were tested at five stocking densities of 4 (T1), 8 (T2), 16 (T3), 24 (T4), and 32 (T5) prawns/m2 in triplicates. The mean initial weights (±SD) of prawns were 5.20 ± 0.42 g (T1), 5.10 ± 0.48 g (T2), 5.18 ± 0.54 g (T3), 4.87 ± 0.92 g (T4), and 5.05 ± 1.09 g (T5), respectively. The survival rate (83.3%), mean final weight (24.93 g), daily weight gain (0.33 g), and specific growth rate (2.61) were the highest in T1, while the most efficient feed conversion ratio (1.57) was in T2. The prawn yields were higher at higher stocking densities (T3 to T5). The stocking density of 8 prawns/m2 is feasible for good growth performance, while the estimated density for optimum yield was 23.5 prawns/m2, indicating that all‐female prawns are amenable to intensive farming. The presence of virgin females ranged from 30% in T1 to 14% in T5, but the distribution of ovarian stages was not significantly different among the stocking densities tested. The gonadosomatic index values showed no significant difference among the treatments. The results indicated that while the stocking density significantly affected growth parameters, it had no significant effect on the all‐female prawns' gonadal maturation.

In 2021, trawling operations in the Arafura Sea were permitted to resume after a moratorium of several years. Therefore, this research aimed to provide up-to-date information to support sustainable tiger prawn management. Data were collected through field surveys and fishing trips aboard a double rig bottom trawler over a one-year fishing cycle (12 months) from February 2023 to January 2024. The monthly tiger prawn catch volume and size composition were recorded and analysed descriptively. The average daily catch was highest in November (803 kg/day) and lowest in May and June (86 kg/day and 64 kg/day, respectively). Tiger prawn weight range was 15-107 g. The most frequently caught size classes were large T-18 (mean 83.3 g/prawn, total volume 13,380 kg) and small T-100 (mean 15 g/prawn, total volume 861 kg). The predominant processed (headless) prawn size classes were L (1,488 kg) and S (614 kg). From December to January, the percentage of small prawns (T-60 to T-100, S and SS classes) increased significantly; therefore, a closed fishing season covering these months is recommended.

Chitin was first discovered by its name from the Greek word “chiton”, which means “mail coat”. It is indeed a polysaccharide made up of naturally occurring acetyl-D-glucosamine monomers. Hatchett was the first researcher who extracted chitin from the shells of mollusks (crabs and lobsters), prawns, and crayfish in 1799. Later in 1811, Henri Braconnot discovered chitin in the cell walls of mushrooms and called it “fungine”. Chitin and chitosan are abundant in the biosphere as essential components of many organisms’ exoskeletons and as by-products of the global seafood industry. The biopolymer must be deacetylated before chitosan can be produced. It can also be extracted using microbes in a biological extraction procedure. The development of products that take advantage of the bioactivities of the existing primary commercial source of chitin (crustacean) has lagged expectations. Also, the disadvantages of the present commercial source such as seasonality and competition for other uses among others has been one of the driving forces towards seeking alternative sources of chitin and chitosan in nature. This review highlights some of the efforts made by environmental scholars to locate possible commercial sources of chitin and chitosan in nature over time.

The giant freshwater prawn, Macrobrachium rosenbergii , is an important species for Bangladesh’s national economy, aquatic biodiversity, and employment opportunities; furthermore, human health risk associated to consumption of this species has become a crucial issue. Eight trace metals (Pb, Cr, Ni, Cd, Fe, Cu, Zn, and Mn) in different body parts of M. rosenbergii (U/10 as large and U/12 and U/15 as medium size), and water collected from farm and wild sources along with the human health risks were assessed in this study. Except Cd, all trace metals exceeded the maximum permissible limits proposed by different authorities. Elevated levels of Pb, Cr, Fe, Cu, Zn, and Mn were found in the wild-caught prawn, whereas Ni and Cd were higher in farmed prawn. A higher trace metal contamination was recorded from the cephalothorax part than the abdomen of both sized prawns. However, trace metal concentrations between two sizes of prawns were not statistically significant ( p > 0.05 ). The estimated daily intakes (EDI) values were higher than the recommended and/or tolerable daily intake for Pb and Cr. Moreover, the target hazard quotient (THQ) values were > 1 for Pb, Cd, Cu, and Zn, elucidating non-carcinogenic risks to the consumers. In addition, the target cancer risk (TR) values of Pb and Ni were high and exceeded the acceptable guideline of 10 −6 , explicating the possibility of carcinogenic risks. Therefore, the study concludes that the consumption of the studied prawn species contaminated with elevated levels of toxic metals is associated with higher degree of potential health risks.

Macrobrachium macrobrachion is an African native brackish river prawn with a high commercial value. Currently, there is little information on the post‐larval production of this species. Two experiments were conducted in the laboratory to develop production techniques for this species. The first experiment analyzed the duration of yolk resorption and the second described the larval stages. Yolk resorption was studied in 240 newly hatched larvae for 24 h based on the reduction in yolk area over time. For larval development stages, six breeding tanks containing 100 L with a density of 50 larvae/L were used. Larvae were fed a combination of Artemia nauplii, Brachionusplicatilis, and pelleted food (Larviva ProStart, Biomar Efico). The results have shown that the area of yolk reserves varied significantly in the hours after hatching. At 14 h after hatching, each larva resorbed approximately 85% of its yolk reserve, and at 18 h after hatching, each of them still had approximately 6.1%. Twelve larval stages were identified and described in three critical stages. M. macrobrachion larvae are lecithotrophic and need to start exogenous feeding at 14 h at the earliest and 18 h at the latest after hatching. These results are the first to highlight the potential for mass production of brackish river prawns.

In the Lixiahe region of China, co-culture has been rapidly promoted in flooded paddy fields owing to its ecological and economic benefits. Rice-prawn co-culture can reduce the damage of crab and shrimp to rice growth and paddy field and substantially change the soil microbial community and soil fertility. In this study, we compared changes in the soil microbial community and soil fertility in waterlogged paddies under conventional rice culture (CR), rice-prawn ( Macrobrachium nipponense ) co-culture (RP), and pond culture (PC). The microbial abundance in RP was significantly higher than that in CR. RP soil microbial diversity was significantly higher than PC soil microbial diversity. The dominant bacteria in RP soil were Proteobacteria , Chloroflexi , and Bacteroidetes . Compared with those in CR, total organic matter (TOM) and total nitrogen in RP were relatively stable, available potassium and available phosphorus (AP) decreased, and other indicators increased significantly. Soil fertility significantly benefited from co-culture, with total organic carbon (TOC) increasing. Interactive relationship analysis showed that TOM, TOC, AP, and NH 4 + -N were the main factors affecting the microbial community. Co-occurrence network analyses showed that network modularity increased with co-culture, indicating that a unique soil microbial community formed under co-culture, improving the adaptability and tolerance to co-culture. Thus, RP is a suitable culture method for this commercially important species. The results of this study can inform the practical operation of fertilizer use and sustainable development of rice-prawn aquaculture systems. Key points • Microbial abundance and diversity increased under rice-prawn co-culture. • Co-culture significantly improved soil fertility, with an increase in TOC. • Rice-prawn co-culture is an ecologically suitable culture method for prawns.

The purpose of this study was to investigate the presence of pathogenic bacteria, specifically Escherichia coli and Salmonella and Vibrio species, and their antimicrobial resistance in shrimp aquaculture facilities of Bagerhat (Bangladesh). Sediment samples were collected from both Penaeus monodon and Macrobrachium rosenbergii farms and shrimp samples from the Macrobrachium rosenbergii facility. The abovementioned bacteria were not found, but five Enterobacterales (Proteus penneri, Proteus alimentorum, Morganella morganii, Enterobacter hormaechei subsp. xiangfangensis and Plesiomonas shigelloides) were detected. This is the first documented case of Enterobacter hormaechei subsp. xiangfangensis in a shrimp farm. Nine antibiotics—ampicillin, gentamicin, chloramphenicol, oxytetracycline, nitrofurantoin, levofloxacin, ciprofloxacin, azithromycin, and co-trimoxazole—were selected for antibiotic resistance testing, and the majority (88.9%) had at least one isolate that was resistant. Across sources, 78.0% of isolates were resistant to at least one antimicrobial, and multidrug resistance was also detected in 29.3% of all isolates. Despite the low number of samples analyzed, nine in total, the results of this experiment emphasize that shrimp farms in Bagerhat may have a problem with antimicrobial-resistant bacteria. This could have negative impacts on shrimp quality and consumers’ health.

Recent discussions of healthy and sustainable diets encourage increased consumption of plants and decreased consumption of animal-source foods (ASFs) for both human and environmental health. Seafood is often peripheral in these discussions. This paper examines the relative environmental costs of sourcing key nutrients from different kinds of seafood, other ASFs, and a range of plant-based foods. We linked a nutrient richness index for different foods to life cycle assessments of greenhouse gas (GHG) emissions in the production of these foods to evaluate nutritional benefits relative to this key indicator of environmental impacts. The lowest GHG emissions to meet average nutrient requirement values were found in grains, tubers, roots, seeds, wild-caught small pelagic fish, farmed carp and bivalve shellfish. The highest GHG emissions per nutrient supply are in beef, lamb, wild-caught prawns, farmed crustaceans, and pork. Among ASFs, some fish and shellfish have GHG emissions at least as low as plants and merit inclusion in food systems policymaking for their potential to support a healthy, sustainable diet. However, other aquatic species and production methods deliver nutrition to diets at environmental costs at least as high as land-based meat production. It is important to disaggregate seafood by species and production method in ‘planetary health diet’ advice.

In 1799, Hatchett decalcified shells of crabs, lobsters, prawns and crayfish with mineral acids, observing that they produced a moderate effervescence and in a short time were found to be soft and plastic of a yellowish color and like a cartilage, which retained the original figure. Although this is the first mention of calcified chitin in invertebrates, the discovery of chitin is usually attributed both to Braconnot in 1811 who discovered chitin from fungi, and to Odier in 1823 who obtained a hornlike material after treatment of cockchafer elytra with potassium hydroxide. Chitin was first named fongine by Braconnot and then chitine by Odier. Children revealed the nitrogenous nature of chitin in 1824. The history of chitosan, the main derivative of chitin, dates back to 1859 with the work of Rouget. The name of chitosan was, however, introduced in 1894 by Hoppe-Seyler. In 1876, Ledderhose hydrolyzed arthropod chitin and discovered glykosamin, the first derivative of chitin. This review describes the 220 years of the development of chitin. I have roughly divided the story into five periods: discovery from 1799 to 1894, a period of confusion and controversy from 1894 to 1930, exploration in 1930–1950, a period of doubt from 1950 to 1970, and finally the period of application from 1970. The different periods are illustrated by examples of published studies, in particular from outstanding scholars who have left their mark on the history of this polysaccharide. Although this historic review is not exhaustive, it highlights the work of researchers who have contributed to the development of our knowledge of chitin throughout the 220 years of its history.