Freshwater Prawn Research Articles

Differential expression of neuropeptide F in the digestive organs of female freshwater prawn, Macrobrachium rosenbergii, during the ovarian cycle

Neuropeptide F is a key hormone that controls feeding in invertebrates, including decapod crustaceans. We investigated the differential expression of Macrobrachium rosenbergii neuropeptide F (MrNPF) in the digestive organs of female prawns, M. rosenbergii, during the ovarian cycle. By using RT-qPCR, the expression of MrNPF mRNA in the esophagus (ESO), cardia (CD), and pylorus (PY) of the foregut (FG) gradually increased from stage II and peaked at stage III. In the midgut (MG), hindgut (HG), and hepatopancreas (HP), MrNPF mRNA increased from stage I, reaching a maximal level at stage II, and declined by about half at stages III and IV (P < 0.05). In the ESO, CD, and PY, strong MrNPF-immunoreactivities were seen in the epithelium, muscle, and lamina propria. Intense MrNPF-ir was found in the MG cells and the muscular layer. In the HG, MrNPF-ir was detected in the epithelium of the villi and gland regions, while MrNPF-ir was also more intense in the F-, R-, and B-cells in the HP. However, we found little colocalization between the MrNPF and PGP9.5/ChAT in digestive tissues, implying that most of the positive cells might not be neurons but could be digestive tract-associated endocrine cells that produce and secrete MrNPF to control digestive organ functions in feeding and utilizing feed. Taken together, our first findings indicated that MrNPF was differentially expressed in digestive organs in correlation with the ovarian cycle, suggesting an important link between MrNPF, the physiology of various digestive organs in feeding, and possibly ovarian maturation in female M. rosenbergii.

Global Status of Giant Prawn, &lt;i&gt;Macrobrachium rosenbergii&lt;/i&gt; Farming with Special Reference to India and Measures for Enhancing Production

Macrobrachium rosenbergii widely known as Giant Prawn (GP) is one of the most important freshwater prawn species widely cultured in several tropical and sub-tropical countries around the world. The global production of GP in 2021 was 3,13,756 t with a value of over $ 2.45 billion. China is the top producer with a production of 1,71,263 t accounting for 54.4% of the global production. Bangladesh, Thailand, Myanmar, and India are the other major producers of GP. India used to be the second largest producer of GP in 2005, however, since then the production showed a declining trend till 2012 with production declining from 42,800 t in 2005 to 3,333 t in 2012. The major reasons for the declining production were slow growth rate, outbreak of diseases and low survival during grow-out, which led to poor production and declining profit for the farmers. However, since 2013 there has been a gradual increase in production till 2020, and in 2021 the production showed a 2.5-fold increase from 2020 production. Considering the huge natural resources available for GP farming in the country and the high value it fetches, demand in domestic and export markets, and its potential to enhance the income of farmers, there is an urgent need to further expand GP farming in India. The present paper provides a brief status update on global GP farming with special reference to India and suggests measures for enhancing the aquaculture production of GP in India.

Integrated analysis of transcriptomic and physiological responses to cold stress in Macrobrachium rosenbergii

The giant freshwater prawn (GFP), Macrobrachium rosenbergii, stands out as a vital species in freshwater shrimp aquaculture. However, its susceptibility to cold conditions has increased the cost of aquaculture and limited the growth of GFP cultivation. To furnish insights at the molecular level to enhance GFP's cold tolerance, transcriptome sequencing and physiological analysis of the hepatopancreas were performed in our study. Initially, we identified 4909 differentially expressed genes (DEGs) between experimental (15 °C, 24 h) and control groups (25 °C, 24 h). These DEGs were significantly enriched in the proteasome, spliceosome, lysosome, peroxisome, and lipid metabolism-related pathways including glycerolipid metabolism, sphingolipid metabolism, linoleic acid metabolism as well as steroid hormone biosynthesis. Histological examination following various stress durations revealed a notable increase in hepatocyte vacuoles after 6 h of cold stress. Hepatocyte structure deterioration occurred in the later phase (48 h), coinciding with a significant increase in cell apoptosis. Subsequent analyses demonstrated an initial increase followed by a decrease in superoxide dismutase (SOD), catalase (CAT), and glutathione (GSH) content, while malonaldehyde (MDA) content rose with stress duration. Furthermore, a significant increase in triglyceride content and no significant change in cholesterol content was observed. RT-qPCR results unveiled significant down-regulated expression of FAS, TAGL, ACOX1, ACS and significant up-regulated expression of GPAT and DEGS. These findings suggest that oxidative stress and impaired lipid metabolism underlie the poor cold tolerance of GFP.

The impact of salinity and temperature stress on survival, behaviour, immune response, and proximate composition of giant freshwater prawn Macrobrachium rosenbergii

The impact of salinity and temperature stress on survival, behaviour, immune response, and proximate composition of giant freshwater prawn Macrobrachium 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.

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.

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;

Population structure and abundance of the amphidromous prawn Macrobrachium tenellum (Smith, 1871) (Decapoda: Caridea: Palaemonidae) in the lower basin of Ameca River, western Mexico, before anthropogenic modifications

Abstract The population of the freshwater prawn Macrobrachium tenellum (Smith, 1871) in four sites in the lower part of the coastal plain of the Ameca River, Mexico is analyzed before drastic anthropogenic modifications of the riverbed occurred. Of the 7,100 individuals of M. tenellum collected between February 2015 and January 2016, 45.7% of which were females (3,250), 4.3% ovigerous females (309), 39.3% males (2,79), and 10.6% undifferentiated (750). Males were significantly larger and heavier than females. In general, the largest individuals were collected at the most distant sites from the coastline (Colomo and San Juan), whereas the smallest ones were captured near the river mouth. The sex ratio (males:females 1:1.3) deviated from the expected 1:1. The length-weight relationship of females, males, and the population in general indicated a negative allometric growth for all three groups. The results of our research may serve as a reference point for future investigations assessing the impact of anthropogenic changes on M. tenellum populations.

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.

Optimal temperature and thermal tolerance of postlarvae of the freshwater prawn Cryphiops (Cryphiops) caementarius acclimated to different temperatures

In this study, the optimum temperature and thermal tolerance of postlarvae of the commercially important freshwater prawn Cryphiops (Cryphiops) caementarius were determined after acclimation to six different rearing temperatures (19 °C, 22 °C, 24 °C, 26 °C, 28 °C, and 30 °C) during a 45 day-culture period. Best growth parameter values were obtained within the temperature range of 24 °C to 28 °C, where the optimum temperature for growth was found to be at 26 °C (weight gain 81.70%; specific growth rate 1.33 %/day) but had not significant effect (p > 0.05) on survival (64%–71%) of postlarvae. Increasing the acclimation temperature significantly (p < 0.05) increased both the critical thermal maximum (CTMax: from 33.82 °C to 38.48 °C) and minimum (CTMin: from 9.27 °C to 14.58 °C). The thermal tolerance interval increased (p < 0.05) from 24.55 °C to 25.48 °C in postlarvae acclimated at 28 °C but decreased (p < 0.05) to 23.90 °C in those acclimated at 30 °C. The acclimation response rate was lower for CTMax and higher for CTMin. The current (12.48 °C) and future (9.48 °C) thermal safety margins were like those reported for other tropical crustaceans. A thermal tolerance polygon over the range of 19–30 °C resulted in a calculated area of 242.25 °C2. The presented results can be used for aquaculture activities and also to help to protect this species against expected climate warming impacts.

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

Effects of astaxanthin in diet on antioxidant capacity and molting-related genes expression of larvae giant freshwater prawn (Macrobrachium rosenbergii)

This experiment was carried out to determine the effects of astaxanthin on reactive oxide species (ROS), antioxidant capacity as well as molting-related genes expression in larvae of giant freshwater prawn, Macrobrachium rosenbergii. A total of 90,000 larvae were assigned to five treatments with six replicates each. Astaxanthin mixed in steamed eggs with graded effective content as 0 (control, A0), 40 (A40), 80 (A80), 160 (A160) and 320 (A320) mg kg−1 were fed to larvae for 14 days. The results showed that ROS of larvae in astaxanthin treatments was significantly lower than the control (P < 0.05). T-AOC, T-SOD and GR activities under astaxanthin treatments generally showed a downward trend and decreased significantly than the control (P < 0.05). No significant difference was observed towards CAT activities among A40 and A80, but the values were markedly greater than A0, A160, A320 (P < 0.05). Larvae in A80 exhibited stronger MDA content than the other (P < 0.05). GSH-Px activity was significantly highest in A320 than the other treatments (P < 0.05). The expression of molt-inhibiting hormone (MIH) in A40 and A80 enhanced markedly than the control (P < 0.05). The elevated expression of Ecdysone receptor (EcR) was recorded only in A160 and A320 (P < 0.05). Chitinase (CHIT) expression among treatments was significantly downregulated than the control except for A40. Heat shock protein (HSP21) and chitooligosaccharidolytic beta-N-acetylglucosaminidase-like expression increased dramatically in A160 and A320 (P < 0.05). For actin 6 gene, higher expression was happened only in A40 compared to control, others presented drop expression in very low level (P < 0.05). This study provides a theoretical basis that 320 mg/kg astaxanthin was excessive level, and might decreased partial antioxidant indexes and influenced molting genes expression of larvae M. rosenbergii.

Development of Semolina Starch/Agar-Based Intelligent Films by Incorporating Butterfly Pea Flower Anthocyanins to Monitor the Freshness of Prawns

The natural plant-derived pH indicator film which monitors food freshness during storage has gained attention among researchers due to consumer awareness of food quality, freshness, and food safety. This study aims to develop a semolina/agar-based film (S/A) incorporated with anthocyanins from butterfly pea flower extract (BPE) as a freshness indicator for tiger prawns and freshwater prawn during 4 days of storage at 4±1 °C. The semolina/agar-based butterfly pea extract (S/A/BPE) films were developed with different concentrations of BPE (3, 6, and 9%) by casting method. Increasing BPE up to 9% in the S/A film increased the thickness and moisture content, lowering the films’ water permeability. The film also had a smoother surface structure with a darker colour. Different pH solutions (pH 2.0-12.0) also changed the colour of films, depending on the BPE concentrations. The application of S/A/BPE films on tiger prawns and freshwater prawns caused colour changes from dark blue at day 0 (fresh stage) to intense green at day 2 (beginning of spoilage) indicating the spoilage of samples. The pH values of both prawns were gradually increased. However, no major changes were observed in the texture profile analysis. These results indicate that S/A/BPE film has the potential to be used as a pH indicator film to detect the freshness of prawn samples.

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

Utilization of vinegar-enriched diets in the growth and survival rate of giant freshwater prawn (Macrobrachium rosenbergii)

Utilization of vinegar-enriched diets in the growth and survival rate of giant freshwater prawn (Macrobrachium rosenbergii)

Identification of genes regulated by 20-Hydroxyecdysone in Macrobrachium nipponense using comparative transcriptomic analysis

BackgroundMacrobrachium nipponense is a freshwater prawn of economic importance in China. Its reproductive molt is crucial for seedling rearing and directly impacts the industry’s economic efficiency. 20-hydroxyecdysone (20E) controls various physiological behaviors in crustaceans, among which is the initiation of molt. Previous studies have shown that 20E plays a vital role in regulating molt and oviposition in M. nipponense. However, research on the molecular mechanisms underlying the reproductive molt and role of 20E in M. nipponense is still limited.ResultsA total of 240.24 Gb of data was obtained from 18 tissue samples by transcriptome sequencing, with > 6 Gb of clean reads per sample. The efficiency of comparison with the reference transcriptome ranged from 87.05 to 92.48%. A total of 2532 differentially expressed genes (DEGs) were identified. Eighty-seven DEGs associated with molt or 20E were screened in the transcriptomes of the different tissues sampled in both the experimental and control groups. The reliability of the RNA sequencing data was confirmed using Quantitative Real-Time PCR. The expression levels of the eight strong candidate genes showed significant variation at the different stages of molt.ConclusionThis study established the first transcriptome library for the different tissues of M. nipponense in response to 20E and demonstrated the dominant role of 20E in the molting process of this species. The discovery of a large number of 20E-regulated strong candidate DEGs further confirms the extensive regulatory role of 20E and provides a foundation for the deeper understanding of its molecular regulatory mechanisms.

Determination of minimum inhibitory concentration for chitosan extracted from freshwater prawn, Macrobrachium dayanum (Henderson, 1893) against Gram negative bacteria

Determination of minimum inhibitory concentration for chitosan extracted from freshwater prawn, Macrobrachium dayanum (Henderson, 1893) against Gram negative bacteria

A report on freshwater prawn, Macrobrachium lamarrei (Crustacea : Decapoda) from river Gomti, Lucknow (U.P.), India

A report on freshwater prawn, Macrobrachium lamarrei (Crustacea : Decapoda) from river Gomti, Lucknow (U.P.), India