Freshwater Prawn Macrobrachium Rosenbergii Research Articles

Insights into the mechanism of color formation of the freshwater prawn (Macrobrachium rosenbergii) revealed by de novo assembly transcriptome analysis

Body color is an important visual indicator of crustacean quality and plays a major role in consumer acceptability, perceived quality, and the market price of crustaceans. The freshwater prawn (Macrobrachium rosenbergii) has two distinct phenotypic variations, characterized by dark blue and light yellow body colors. However, the underlying mechanisms regulating the body color of M. rosenbergii remain unclear. In this study, the composition of shell color parameters and pigment cells of raw and cooked dark blue and light yellow M. rosenbergii was investigated and the mechanisms associated with body color were elucidated by transcriptome analysis. The results showed significant differences in the raw shells of the dark blue and light yellow M. rosenbergii (L: 26.20 ± 0.53 vs. 29.25 ± 0.45; a: −0.88 ± 0.19 vs. 0.35 ± 0.18; b: 1.73 ± 0.20 vs. 3.46 ± 0.37; dE: 70.33 ± 0.53 vs. 67.34 ± 0.45, respectively, p = 0.000) as well as the cooked shells (L: 58.14 ± 0.81 vs. 55.78 ± 0.55; a: 19.30 ± 0.56 vs. 16.42 ± 0.40; b: 23.60 ± 0.66 vs. 20.30 ± 0.40, respectively, p < 0.05). Transcriptome differential gene analysis obtained 39.02 Gb of raw data and 158,026 unigenes. Comprehensive searches of the SwissProt, Nr, KEGG, Pfam, and KOG databases resulted in successful annotations of 23,902 (33 %), 40,436 (25.59 %), 32,015 (20.26 %), 26,139 (16.54 %), and 22,155 (14.02 %) proteins, respectively. By KEGG pathway analysis, numerous differentially expressed genes were related to pigmentation-related pathways (MAPK signaling pathway, Wnt signaling pathway, melanin production, tyrosine metabolism, and cell-cell communication process). Candidate DEGs that may be involved in body color included apolipoprotein D, crustacyanin, cytochrome P450, and tyrosinase, as verified by quantitative real-time PCR. The results of this study provide useful references to further elucidate the molecular mechanisms of color formation of M. rosenbergii and other crustaceans.

Characterization of a novel immune deficiency gene of Macrobrachium rosenbergii reveals antibacterial and antiviral defenses.

We sought to identify and characterize an immune deficiency (IMD) homolog from the giant freshwater prawn (also known as the giant river prawn) Macrobrachium rosenbergii. The IMD is a death-domain-containing protein that plays a crucial role as an adaptor protein in the IMD pathway-one of the most important response mechanisms to viral and bacterial invasion of invertebrates. An IMD homolog gene from M. rosenbergii (MrIMD) was isolated using rapid amplification of complementary DNA ends. The tissue distribution and response to immune challenge of MrIMD were analyzed by real-time reverse transcription polymerase chain reaction to understand the regulatory mechanism of MrIMD messenger RNA (mRNA) expression in M. rosenbergii. The open reading frame of MrIMD comprised 555 nucleotides encoding a protein consisting of 184 amino acids, with a conserved death domain at the C-terminus. The MrIMD protein demonstrated 53-74% similarity with IMDs from other crustaceans; the highest similarity was with the IMD from the oriental river prawn M. nipponense. Gene expression analysis revealed that MrIMD mRNA levels were highest in gill tissues. After Aeromonas hydrophila stimulation, MrIMD was significantly upregulated in the muscle, gills, and intestine, whereas there was no significant difference in the hemocytes and hepatopancreas. In the case of Macrobrachium rosenbergii nodavirus stimulation, MrIMD was dramatically upregulated in the muscle and hepatopancreas, whereas downregulation was observed in the gills. These results suggest that the MrIMD gene may play different roles in response to gram-negative bacteria and viral infection and plays a crucial role in innate immunity as an important key molecule in the defense against bacterial and viral infections.

Coinfection with infectious precocity virus and Decapod iridescent virus 1 in farmed giant freshwater prawn (Macrobrachium rosenbergii)

In the past few years, outbreaks of infections with infectious precocious virus (IPV) and Decapod iridescent virus 1 (DIV1) have significantly hindered the development of the aquaculture industry of giant freshwater prawn (Macrobrachium rosenbergii) and caused severe economic losses in China. To understand the epidemiological information of farmed M. rosenbergii, we collected 79 samples from 23 farming ponds in Jiangsu Province from 2022 to 2023 and detected 8 common pathogens. The results showed that IPV and DIV1 could be detected in collected samples. Infections with IPV or DIV1 and the resulting diseases were confirmed by clinical signs, histopathologic examination, and qPCR. At the same time, we found coinfection with IPV and DIV1 in the same individuals by clinical diagnosis, histopathologic examination, and molecular testing. However, iron prawn syndrome (IPS) or IPS equivale and clinical infection with DIV1 (iDIV1) cases showed mutual exclusion in individuals and ponds. The results revealed significant differences in loads of the two viruses in the same individuals and ponds, with an overall negative correlation. This is the first report of coinfection with IPV and DIV1 in farmed M. rosenbergii.

Nursery rearing freshwater prawn, Macrobrachium rosenbergii, in biofloc system integrated with red seaweed, Gracilaria tenuistipitata, at different stocking densities under zero water exchange

This study was conducted to assess the effects of stocking densities on the water quality, survival and growth of the freshwater prawn Macrobrachium rosenbergii postlarvae (PL) cultured in a biofloc system integrated with red seaweed (Gracilaria tenuistipitata). Postlarvae prawns weighing 0.012±0.001 g were stocked at densities of 1,000, 1,500, 2,000, and 2,500 PL/m3, noted as D1, D1.5, D2, and D2.5, respectively. Each density treatment was replicated three times and randomly assigned to 12 plastic tanks of 150 l at a salinity of 10 ppt. Red seaweed was added at a rate of 1.5 kg/m3, and molasses was used as a carbon source to maintain a C:N ratio of 15:1. No water exchange occurred during the 30-day rearing period. Results indicated that water quality parameters, including TAN and NO2-, biofloc volume, total heterotrophic bacteria, and Vibrio spp. counts, increased at higher prawn densities but remained within the appropriate range for prawn performance. Growth rate in weight and survival of prawns decreased as stocking density increased, with D1 and D1.5 showing comparable and significantly higher results compared to D2 and D2.5. Prawn production increased with rising stocking density, with a significant difference among treatments (p&lt;0.05). Furthermore, prawns in D1 and D1.5 exhibited significantly higher feed efficiency than those in D2 and D2.5. These findings suggest that nursery rearing of prawn PL at a density of 1,500 ind/m3 in a biofloc system integrated with red seaweed offers optimal growth and feed efficiency, while maintaining good water quality and conserving water resources.

The trophic state of the reservoir influences the allometric coefficient and condition factor of Giant Freshwater Prawn (Macrobrachium rosenbergii) cultured in perennial reservoirs of Sri Lanka

Giant Freshwater Prawn (Macrobrachium rosenbergii) is an essential crustacean species in culture-based fisheries of Sri Lanka. Studying the morphometric characteristics and empirical models in fishing and aquaculture is highly beneficial; thus, it is the most accurate way of analyzing growth patterns. The present study aimed to establish the length-weight relationship and compute the relative condition factor for the M. rosenbergii cultured in trophically different perennial reservoirs in Sri Lanka, considering the trophic status of the reservoirs. The allometric coefficient and condition factor of M. rosenbergii concerning the trophic state of the reservoir were empirically ascertained from the samples collected from twenty-five dry-zone perennial reservoirs of Sri Lanka. Carlson's Trophic State Index (TSI) was calculated based on the chlorophyll-a content. The allometric coefficient and relative condition factor were computed using the total length and weight of the M. rosenbergii. The TSI ranging between 44.09±0.47 and 65.15±0.24 differed significantly (p&lt;0.05). Sexual dimorphism in the growth of males over the female M. rosenbergii was ascertained with the aid of allometric coefficient (b value) 3.2306 (positive allometric growth) and 2.9534 (negative allometric growth), respectively. In eutrophic perennial reservoirs, Giant Freshwater Prawns showed the highest allometric coefficient in both sexes. There was a positive correlation between the allometric coefficient and TSI among males, r(23)=0.7210, p&lt;0.001, and combined sexes, r(23)=0.7900, p&lt;0.001, respectively. The results of the present study revealed that the trophic state of the reservoir influences the allometric coefficient and condition factor of M. rosenbergii cultured in perennial reservoirs of Sri Lanka.&#x0D;

Differential responses of hepatopancreas transcriptome between fast and slow growth in giant freshwater prawns (Macrobrachium rosenbergii) fed a plant-based diet

Efficient utilisation of plant-based diets in the giant freshwater prawn, Marcrobrachium rosenbergii, varies according to individual, suggesting that it might be associated with differences in physiological and metabolic responses. Therefore, we aimed to investigate the individual differences in the growth response of shrimp fed to a soybean-based diet (SBM). Two hundred shrimp were fed SBM for 90 days, and specific growth rate (SGR) was determined individually. Fast- and slow-growing shrimp (F-shrimp vs. S-shrimp), with the highest and lowest 5% SGRs, respectively, were sampled to determine haemolymph chemistry and carcass composition. The hepatopancreas of these shrimps were used for transcriptome analysis through RNA sequencing (RNA-Seq). The results showed no significant differences in haemolymph chemistry parameters. In terms of carcass proximate composition, F-shrimp exhibited higher protein composition than did S-shrimp, suggesting that F-shrimp have higher protein anabolism. Using RNA-seq and real-time reverse transcription polymerase chain reaction (qRT-PCR), the expression levels of several genes encoding physiologic and metabolic enzymes were found to be upregulated in F-shrimp compared to in S-shrimp, suggesting that these enzymes/proteins mediated the efficient use of SBM-based diets for growth promotion in shrimp. Various DEGs associated with the immune system were observed, indicating a difference in immune processes between F- and S-shrimp. The expression of several housekeeping genes was found to be upregulated in S-shrimp. Collectively, the upregulated expression of several enzymes associated with physiological and/or metabolic processes and increased protein anabolism may be attributed to the efficient use of SBM for maximal growth in shrimp.

Linking genetic lineages of giant freshwater prawn Macrobrachium rosenbergii to their global populations

Linking genetic lineages of giant freshwater prawn Macrobrachium rosenbergii to their global populations

Quantitative analysis of infectious precocity virus load and stunted growth syndrome via an immunohistochemical assay and reverse transcriptase quantitative real-time PCR in Macrobrachium rosenbergii

The giant freshwater prawn Macrobrachium rosenbergii (M. rosenbergii) is susceptible to a flavivirus known as the infectious precocity virus (IPV). The symptoms of infection, such as sexual precocity and stunted growth, collectively constitute what is referred to as iron prawn syndrome (IPS). IPV manifests as a persistent, long-term infection marked by subtle morphological changes that pose challenges for detection. Prawns suspected of early-stage infection do not necessarily present clear clinical signs. This study investigated IPV diagnostics based on clinical signs, immunohistochemistry (IHC), and reverse transcriptase quantitative real-time PCR (RT-qPCR) in prawns suspected of IPV-infection. We also explored the correlations among the three diagnostic approaches. Some clinical signs are easily observable, such as shorter body length, mature gonads, elongated blue claws, blue tailfins, and darker body coloration; however, they are not absolute signs of infection. Additionally, many infected prawns do not exhibit clear clinical signs during the early stages. We produced anti-IPV serum and then applied it via IHC staining to highlight the location of the virus. Positive signals were observed in the perinuclear cytoplasm of haemocytes in the hepatopancreas, gills, and pereiopods. IPV-positive signals were also detected in support cells within the lamina ganglionaris as well as in neurosecretory cells within the bellonci organ, sinus glands, and the X organ. The detection of IPV-positive signals in prawns without clinical signs demonstrates the value of this diagnostic method. IHC analysis was used to distinguish between IPV-positive and IPV-negative prawns, and also used in conjunction with RT-qPCR to quantify viral loads in these two groups. The IPV viral loads were as follows: IHC-positive prawns (> 103.5 copies/ μg) and IHC-negative prawns (< 103.5 copies/ μg). Note that the highest numbers of viral copies were observed in pleopods, which are easily obtained and do not necessitate sacrificing the animal. In conclusion, the correlation between viral load and IHC pathological diagnosis could be used to identify cases of IPV infection, while providing valuable insights into disease prevention and prognosis.

Growth and survival rate of giant freshwater Prawn Macrobrachium rosenbergii (De Man, 1879) fed with Terminalia catappa seed meal

Growth and survival rate of giant freshwater Prawn Macrobrachium rosenbergii (De Man, 1879) fed with Terminalia catappa seed meal

Microplastic Contamination in the Tissue of Giant Freshwater Prawns Macrobrachium rosenbergii, Thailand

Microplastics are everywhere and may be harmful to the biota environment. This study investigated microfiber contamination in giant freshwater prawn tissues, one of Thailand’s economic species. The prawn samples were taken from the Trang River in southern Thailand in September 2022. Three tissue sections (head, middle, and tail) of 60 prawns were studied and the samples were digested with 10 % potassium hydroxide (KOH) solution. We utilized a stereomicroscope to study the microplastics and Fourier transform infrared spectroscopy (FT-IR) to determine the types of polymer. There were 3.50 ± 0.34 microfibers in the head per 5 g weight, 2.87 ± 0.29 per 5 g weight in the middle, and 3.10 ± 2.28 per 5 g weight in the tail. Fiber appearance is obvious, the predominant color is blue, the most common size is in the range of 101-500 µm, and the polymer type found is cotton rayon polypropylene (PP). The correlation analysis of microfiber content (in the stomach and intestine), carapace length, abdomen length, stomach weight, and body weight in giant freshwater prawns was not correlated with tissue microfiber content (p &gt; 0.01). It was found that the number of microplastics in giant freshwater prawns was not significantly different (p &gt; 0.05) among the 3 sections of prawn tissue (head tissue, middle tissue, and tail tissue). HIGHLIGHTS Digestion of prawns with KOH 10 % Microplastic contamination was discovered in giant freshwater prawn tissues Fiber shape was most found in giant freshwater prawns The polymer type discovered is cotton rayon polypropylene GRAPHICAL ABSTRACT

Toxicidade aguda da amônia total para pós-larvas de Macrobrachium rosenbergii em diferentes níveis de salinidades

Abstract Nitrogen compounds, particularly ammonium, nitrite and nitrate, are a major problem in shrimp production systems. These compounds can accumulate in the aquatic environment and reach harmful or even lethal levels. Thus, monitoring the levels of nitrogenous compounds such as ammonia and studying their effects on the animals are essential. One tool used for this purpose is acute toxicity testing based on the evaluation of LC50 values. Furthermore, tools that can help improve the performance of aquatic organisms in culture are needed. The present study aimed to evaluate the effect of salinity on the toxicity of total ammonia to postlarvae of the freshwater prawn Macrobrachium rosenbergii. For this purpose, acute toxicity testing (LC50-96h) was performed using 540 postlarvae with a mean weight of 0.13 g and a mean total length of 2.47 cm, divided into 54 experimental units of two liters each. A completely randomized design in a 3×6 factorial scheme was used, combining three salinities (0, 5, and 10 g.L-1) and six total ammonia concentrations (0, 8, 16, 32, 64, and 128 mg.L-1), with three replicates per combination. The LC50 values for M. rosenbergii postlarvae at 24, 48, 72, and 96 h and their respective confidence intervals (95%) were estimated using the trimmed Spearman-Karber method. The results showed that salinities of 5 or 10 g.L-1 did not reduce the acute toxicity of total ammonia.

Culture of Fresh Water Prawn Macrobrachium rosenbergii and Its Cost Benefit Analysis Using Low Cost Feed

Fresh water prawn culture has great potential for rural aquaculture, generating considerable employment and income for rural and poor people. Fresh water prawn farming is environmentally sustainable as it is usually practiced in low stocking density. Fresh water prawn culture has attracted more attention in the recent years due to its export potential and increasing demand as good protein. The seeds of Macrobrachium rosenbergii were collected from Thanjavur breeders and immunized seedling were introduced into the culture ponds. The stocking density 1200 numbers/pond. The size of fingerlings from 4 to 8 cm. The feed were given to the prawn which was consisted of fish meal 20%, soya meal 9%, rice brown 45%, coconut oil cake 20%, tapioca starch 5% and mineral premix 1%. Total body weight of 10% feed every day. The water quality of the culture pond during the period of culture within the range of water quality parameters. In culture pond with an average stocking size of 3-5 g (average 4 g), the growth at the end of six months ranged between 30.5 g and 56.5 g, the average weight being 48.5 g. The total weight of the prawns at the time of harvest was 50.325 kg. The prawns were sold in two lots. The ones with the bigger size 38.5 kg were sold at Rs.650/kg, while the while the smaller prawns weighing 11.8 kg were sold at Rs. 500/kg. The bigger prawns yielded Rs. 25025, while the smaller ones yielded Rs.5900. Thus, the total income from prawn culture yielded Rs.30925. The total expenditure incurred for this culture amounted to Rs.12800. Thus the total profit from this culture worked out to Rs.18125. When this profit is calculated on a monthly basis, it works out to Rs.3020.8 This study proves that culturing M. rosenbergii is profitable even in small ponds which can economically benefit the lives of the local people.

Effects of Dietary Oil Palm Carotenes on Colour Intensity and Astaxanthin Content in Giant Freshwater Prawn (Macrobrachium rosenbergii)

Prawns have the metabolic ability to convert dietary carotenoids, such as beta-carotene, into astaxanthin, which increases the colour intensity and boosts immunity, thereby improving prawn growth performance. Currently, prawn feed manufacturers are using expensive synthetic astaxanthin as a feed supplement, which leads to higher feed costs. Oil palm carotene can be used in prawn feed production to replace the commercial synthetic astaxanthin in the market. A study was conducted to evaluate the effects of dietary oil palm carotene on the colour intensity, total carotenoids, and astaxanthin content of giant freshwater prawns (Macrobrachium rosenbergii). Five different treatments that are isonitrogenous and isocaloric were used in this study, including T1 (commercial feed); T2 (control, without oil palm carotene); T3 (3% crude palm oil (CPO) inclusion); T4 (3% palm pressed fibre oil (PPFO) inclusion); and T5 (3% commercial oil palm-mixed carotene inclusion). Prawns were fed to satiation five times daily during the 10-week feeding trial. At the end of the feeding trial, prawn samples were collected for colour intensity, total carotenoids, and astaxanthin content analysis. The T4 and T5 prawn samples showed better colour intensity in terms of lightness in cooked samples as well as yellowness and redness for both raw and cooked samples. Prawns fed with diets consisting of oil palm carotenes (T3, T4 &amp; T5) contained higher total carotenoids content (more than 40 ppm) and astaxanthin content (ranging from 14.65 to 16.96 ppm) than the commercial (T1) and control (T2) groups. These results indicate that supplementation of oil palm carotenes in the giant freshwater prawn can potentially replace expensive commercial synthetic astaxanthin that is practically used by aquaculture feed producers.

Monosex Populations of the Giant Freshwater Prawn Macrobrachium rosenbergii-From a Pre-Molecular Start to the Next Generation Era.

Sexual manipulation in the giant freshwater prawn Macrobrachium rosenbergii has proven successful in generating monosex (both all-male and all-female) populations for aquaculture using a crustacean-specific endocrine gland, the androgenic gland (AG), which serves as a key masculinizing factor by producing and secreting an insulin-like AG hormone (IAG). Here, we provide a summary of the advancements from the discovery of the AG and IAG in decapods through to the development of monosex populations in M. rosenbergii. We discuss the broader sexual development pathway, which is highly divergent across decapods, and provide our future perspective on the utility of novel genetic and genomic tools in promoting refined approaches towards monosex biotechnology. Finally, the future potential benefits of deploying monosex prawn populations for environmental management are discussed.

The Effectiveness of selective breeding on the productivity of giant freshwater prawns (Macrobrachium rosenbergii) population

Selection programs for giant freshwater prawns stocks from various locations have been implemented by several government institutions. Some of the results of selective breeding of giant freshwater prawns have been released by the Indonesian Ministry of Marine Affairs and Fisheries. Several giant prawn strains have been released, including GIMacro, GIMacro II, and Siratu. The development of giant prawn strains after release has not been significantly observed among shrimp farmers. Therefore, it is necessary to evaluate its productivity in order to observe its impact on the development of giant prawn aquaculture. The study was conducted using a meta-analysis method with data sources derived from searching the database on Google.com. The result s of this study indicate that selective breeding of giant prawn can successfully increase the productivity of their farming (P< 0.001). It has also been demonstrated that the effectiveness of family selection significantly accelerates the growth rate of giant prawns. It is anticipated that the findings of this study will help formulate policy solutions for reversing the current drop in giant prawn production.

The Composition and Diversity of Intestinal Microbes at Different Growth Stages of Giant Freshwater Prawns (Macrobrachium rosenbergii)

Intestinal bacterial communities play an important role in the growth and health of aquatic animal hosts and have drawn increasing attention. However, the role of the intestinal microbiota in the growth of freshwater prawns remains unclear. Here, the intestinal microbiota of freshwater prawns (Macrobrachium rosenbergii) at different life stages (one, two, and three months old) were investigated using 16S rRNA sequencing. The results showed that community richness and diversity increased with growth, which might be one of the reasons that the prawns maintained a fast growth rate before sexual maturation. Three core phyla were identified in the one-month-old group, namely, Firmicutes (79.24%), Proteobacteria (17.09%) and Actinobacteriota (2.01%). Five core phyla were identified in the two-month-old group, including Firmicutes (47.84%), Proteobacteria (44.22%), Actinobacteriota (1.83%), Acidobacteriota (1.66%) and Bacteroidota (1.24%), and the core phyla in the three-month-old group were similar, except for Acidobacterota, which was not identified. A total of 12 core genera were identified in all samples, and significant differences were observed in the relative abundance of gut microbiota between the three groups (p &lt; 0.05). Exiguobacterium, Lactococcus and Shewanella were the three most significantly differentially abundant genera between stages. In addition, Candidatus Hepatoplasma was detected only in the two- and three-month-old prawn groups. This study provides information on the differences in the intestinal microbiota in different developmental stages, which contribute to adaptation to salinity in the early developmental stage and digestive ability to meet the growth needs of Macrobrachium rosenbergii.

Effect of Different Levels of Dietary Lipids on Reproductive Performance of Captive Broodstock of &lt;i&gt;Macrobrachium rosenbergii&lt;/i&gt;

The present paper reports the results of a laboratory experiment to study the effect of different levels of dietary lipids on reproductive performance of captive broodstock of giant freshwater prawn Macrobrachium rosenbergii. Three formulated pellet diets were prepared containing 2% (D1), 4% (D2) and 6% (D3) lipid and fed to adult females of M. rosenbergii (Av. body weight - 28 g) at 5% of the biomass per day for 60 days. Prawns fed D3 showed significantly higher (P&lt;0.05) weight gain (221.16±6.48 mg/day) compared to those fed D1 and D2. Similarly, significantly higher (P&lt;0.05) reproductive parameters like fecundity (eggs/ g body weight) (1153.6±174.25), egg clutch weight (g) (4.9±0.25) and gonado-somatic index (6.82±0.27) were also found in prawns fed D3. Reproductive effort (g eggs/ female x100), post–hatch fecundity (nos. of larvae/ g female) and mid gut gland somatic index (%) also showed a similar trend. The present results clearly indicated that dietary lipid level of 6% significantly enhances reproductive performance of captive stock of M. rosenbergii compared to 2% and 4% lipid levels.

The Gonadal Maturity and Gene Expressions of Female Giant Freshwater Prawn (Macrobrachium rosenbergii) after Dietary Administration of Medroxyprogesterone Acetate

Abstract One of the problems in giant prawn cultivation is female giant prawns laying eggs during rearing. They will incubate their eggs for three weeks so that the energy from the expected feed for growth is used for egg development and other reproductive activities. Giving MPA hormone to giant prawns either by injection or oral could inhibit gonadal maturation and increase growth rate. The maturation process of the prawn ovary consists of the activation of some complex cellular mechanisms involving genes that regulate the stages of oocyte development. This study aimed to evaluate the response of gonadal maturity and the expression of the MrvWD-Kazal gene in giant prawns fed with a diet containing MPA hormone. The design used in this study was a completely randomized design with four treatments and five replications. The treatments were feeding a diet added with MPA with a concentration of 0 mg.kg-1 feed as control (K), 50 mg.kg-1 feed (P1), 100 mg.kg-1 feed (P2), and 150 mg.kg-1 feed (P3). MPA hormone at a concentration of 50-150 mg/kg feed could inhibit the gonadal maturation of female prawns. In 100 mg/kg of feed concentration showed the lowest gene expression level, indicating an inhibition of gonadal maturation molecularly. The administration of MPA hormone through the feed is a recommended method of aquaculture because it is more applicable and effective than by injection, even though it has a non-uniform impact on each individual. Highlight Research Administration of MPA hormone through the feed to female giant freshwater prawns can inhibit the level of gonad maturity. Expression of von Willebrand factor D (vWD) – Kazal gene were analyzed in different levels of prawn maturity Gonadosomatic index and gonadal histology confirmed that different levels of administration of MPA hormone through the feed could affect the gonad development. The administration of MPA hormone through the feed is a recommended method for aquaculture because it is more applicable and effective to inhibit early maturation of prawns.

Integrated analysis of a miRNA-mRNA network related to immunity and autophagy in Macrobrachium rosenbergii infected with Aeromonas hydrophila

MicroRNAs (miRNAs) are a group of RNAs that regulate gene expression in the post-transcriptionally. miRNAs can regulate numerous processes, such as the immune response, due to their dynamic expression patterns. The giant freshwater prawn Macrobrachium rosenbergii is a major freshwater aquaculture prawn that is attacked by various bacteria, including Aeromonas hydrophila. For this study, we performed an analysis of the miRNA and mRNA transcriptome analysis of M. rosenbergii which was infected with A. hydrophila. We identified 56 differentially expressed miRNAs (DEMs) and 1542 differentially expressed mRNAs. Furthermore, an integrated analysis of miRNA-mRNA expression led to the identification of 729 differentially predicted target genes (DETGs) of the DEMs. Multiple functional categories related to immunity, apoptosis, and autophagy were found to be enriched in the DETGs. During the infection of M. rosenbergii by A. hydrophila, an elaborate regulatory network involving Toll and immune deficiency (IMD) signaling, mitogen-activated protein kinase (MAPK) signaling, lysosome, and cell apoptosis was formed by a complex interplay of 40 crucial DEMs and 22 DETGs, all associated with the immune and autophagy pathway. The findings suggest that infection with A. hydrophila triggers intricate responses in both miRNA and mRNA, significantly impacting immune and autophagy processes in M. rosenbergii.

Utilisation of probiotics for disease management in giant freshwater prawn (Macrobrachium rosenbergii): Administration methods, antagonistic effects and immune response.

The giant freshwater prawn (Macrobrachium rosenbergii) is a high-yielding prawn variety well-received worldwide due to its ability to adapt to freshwater culture systems. Macrobrachium rosenbergii is an alternative to shrimp typically obtained from marine and brackish aquaculture systems. However, the use of intensive culture systems can lead to disease outbreaks, particularly in larval and post-larval stages, caused by pathogenic agents such as viruses, bacteria, fungi, yeasts and protozoans. White tail disease (viral), white spot syndrome (viral) and bacterial necrosis are examples of economically significant diseases. Given the increasing antibiotic resistance of disease-causing microorganisms, probiotics have emerged as promising alternatives for disease control. Probiotics are live active microbes that are introduced into a target host in an adequate number or dose to promote its health. In the present paper, we first discuss the diseases that occur in M. rosenbergii production, followed by an in-depth discussion on probiotics. We elaborate on the common methods of probiotics administration and explain the beneficial health effects of probiotics as immunity enhancers. Moreover, we discuss the antagonistic effects of probiotics on pathogenic microorganisms. Altogether, this paper provides a comprehensive overview of disease control in M. rosenbergii aquaculture through the use of probiotics, which could enhance the sustainability of prawn culture.