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Plants have long been the main focus of the medical industries' attention due to their extensive list of biological and therapeutic properties and ethnobotanical applications. This study investigates the effects of substituting Catharanthus roseus, a medicinal herb favorable in the diet of post larvae (PL) of Macrobrachium rosenbergii, a freshwater prawn. The study assesses the impact on the GC-MS, UV–Vis analyses, and FTIR spectrum through leaf material from C. roseus that was analyzed and found to include a variety of phytochemicals including four of the seven secondary metabolic products discovered in C. roseus leaves showed bioactive principles 2-methylmannoside, squalene, pentatriacontane, and 2,4,4-trimethyl-3-hydroxymethyl-5a-(3-methyl-but-2-enyl)-cyclohexene. Catharanthus roseus is rich in the anticancer compounds vinblastine and vincristine. After that, the compounds undergo molecular in silico assessments docking studies revealed that among these compounds with bioactive properties. After separation, the basal diets of C. roseus crude extract in various ratios 0.5 mg/g, 1 mg/g, 1.5 mg/g, and 2 mg/g for 90 days experimental prides Macrobrachium rosenbergii was fed a diet enriched with C. roseus. At the conclusion of the feeding trial, it was discovered that the C. roseus supplemented feed given prawns had considerably (P < 0.05) greater physiological water parameters such as temperature, pH, salinity, dissolved oxygen, ammonia, and total dissolved solids, have to be within tolerance ranges so as to get the most effective results for M. rosenbergii. The muscle of protein profile such as a white spot disease (WSD) is caused by the white spot syndrome virus (WSSV), which also requires amino acid (AA) and fatty acid (FA); protein VP28 fused was shown to bind to prawn cells in an in vitro binding experiment using Western blot SDS-PAGE gel. Moreover, a respective up- and downregulated crustacean hyperglycemic hormone (MrCHH), myostatin (MrMSTN), peroxidasin (MrPXDN), heat shock protein 70 (MrHSP70), and heat shock protein 90 (MrHSP90) confirmed the impact of C. roseus on prawn development. The prawns that were given a diet containing a 1.5 mg/g concentration of C. roseus feed showed significant enhancements in safe level growth performance. Therefore, the present study proposes that 1.5 mg/g may be used as a dietary supplement safe level for regulating Macrobrachium rosenbergii production more effectively. [ABSTRACT FROM AUTHOR]

The supplementation of cytosine phosphate guanosine-oligodeoxynucleotides (CpG-ODNs) in feeds to enhance the immune responses of crustaceans has been studied. However, the immunomodulatory effects of CpG-ODNs alone on prawn hepatopancreas and midgut remain unclear. Hence, we delivered CpG-ODNs directly into the midgut of Macrobrachium rosenbergii by reverse gavage (RG). In this study, M. rosenbergii was fasted before receiving different doses (0, 2, 4, and 10 μg) of CpG-ODN 2006. Furthermore, the hemolymph, hepatopancreas, and midgut were sampled at 2, 6, 12, and 24 h after RG. The results showed that administration of CpG-ODN 2006 could boost total hemocyte count (THC), transglutaminase (TG), phenoloxidase (PO), lysozyme-like (LYS), and respiratory burst (RB) responses in the hemolymph. In addition, the expression levels of prophenoloxidase (MrProPO), crustin (MrCrs), peroxinectin (MrPxt), and superoxide dismutase (MrSOD) in the hepatopancreas and midgut were also enhanced, in a dose- and time-dependent manner. Overall, our results indicate that administration of 4 μg CpG-ODN 2006 alone by RG elicited the most potent immunological response in the hemolymph, hepatopancreas, and midgut of M. rosenbergii. [ABSTRACT FROM AUTHOR]

The study and diversity of freshwater prawns are of great importance due to growing interest in biodiversity and its relative abundance. The present study was carried out for a selected stream divided into three different habitat types: namely, pond, run, and riffle. The study was focused on the diversity and abundance of prawns. To make it more systematic, a transect was laid upon the stream and it was divided into 30 plots with 100 m intervals. Metapenaeus rosenbergii, Penaeus japonicas, and Metapenaeus insolitus were species recorded in the pond habitat type only. The Penaeus genus was the most prominent in the study area while the genus Metapenaues was the least abundant. The diversity of freshwater prawns was found to be highest in the pond rather than the run and riffle. Documented information for prawn populations in Bhutan is sparse. Therefore, there is a wide research gap regarding prawn diversity in Bhutan. This study will help to establish a baseline data for the prawn distribution in the proposed study area. The present study will serve as a reference guide for future researchers. [ABSTRACT FROM AUTHOR]

Tea tree oil (TTO) is an essential plant oil with diverse antibacterial and antioxidant properties; however, whether the role played by TTO in low fish meal (LF) diets induced the observed effects in the farmed crustaceans remains unclear. Therefore, this study used Macrobrachium rosenbergii as the model crustacean, and an 8-week feeding experiment with NF (normal fish meal), LF (soybean meal replacing 40% fish meal), and LFT (LF with 200 mg/kg TTO) diets was conducted to evaluate the positive effects of TTO under the LF diet. Compared to the NF diet, the LF diet reduced hemolymph antioxidant capacity and non-specific immunity, and induced hepatopancreas apoptosis and damage. However, in comparison with LF, LTF significantly ameliorated morphological impairment in the hepatopancreas, improved hepatopancreas energy metabolism by upregulating the Bcl-2/Bax and Akt/mTOR pathways, and enhanced antioxidant and non-specific immune capacity by activating the NF-κB/NO pathway. In addition, LFT repaired intestinal barrier injury and the imbalance of intestinal microbiota induced by the LF diet. Moreover, the Pearson correlation revealed the variations of the above indicators, which were related to the abundance changes of Klebsiella, Clostridium sensu stricto 12, Thermobifida, Bifidobacterium, and Alistipes, indicating that these microbes might serve as prospective targets for the intestine–hepatopancreas axis to affect hepatopancreas apoptosis, metabolism, and non-specific immunity. In summary, 200 mg/kg TTO supplementation mediated gut microbiota and positively improved energy metabolism and non-specific immunity, thereby alleviating hepatopancreas dysplasia and damage induced by the LF diet in M. rosenbergii. [ABSTRACT FROM AUTHOR]

An acute toxicity study of imidacloprid on the larval health and metamorphosis of the giant freshwater prawn Macrobrachium rosenbergii larvae were carried out during the months of January–August 2021 at the aquatic animal raring and experimenting facility in the Cochin University of Science and Technology, Kerala, India. Imidacloprid is a broad-spectrum neonicotinoid insecticide used against sucking pests infecting agricultural crops as both contact poison and stomach poison. The present study investigated the adverse effects of imidacloprid on the survival rate, feeding behaviour, larval quality and incidence of metamorphosis in Macrobrachium rosenbergii larvae. The 48 h median lethal concentrations (LC50 values) and safe concentration of imidacloprid determined for different larval stages (Zoea I–XI) of M. rosenbergii ranged between 0.000635–0.001388 mg l-1 and 0.000055–0.000191 mg l-1, respectively. Larvae exposed to imidacloprid for 48 h showed decrease in survival rate with increase in concentration of imidacloprid. The results of larval condition index (LCI) that indicates the larval quality showed that imidacloprid reduced the larval health significantly (p<0.05) at high concentrations and is potent to delay the incidence of metamorphosis. The feeding rate of larvae exposed to different concentrations of imidacloprid were found to be significantly (p<0.05) reduced due to paralytic effect of imidacloprid. The present work provides relevant data beneficial for the risk assessment of imidacloprid in M. rosenbergii. [ABSTRACT FROM AUTHOR]

This study examines the effects of the freshwater cyclopoid Thermocyclops decipiens and Artemia nauplii on the growth and survival of Macrobrachium rosenbergii (De Man, 1879) larvae during the rearing phase. M. rosenbergii larvae were divided into three groups and fed exclusively with either Artemia nauplii or T. decipiens, and a mixed diet (50% T. decipiens and 50% Artemia nauplii) in triplicate. The results indicated that M. rosenbergii larvae reached 90% post larvae (PL) on the 23rd day of the mixed diet feeding regime, followed by 88% and 82% PL on the 24th and 26th days when fed with Artemia nauplii and T. decipiens , respectively. The highest length and weight of M. rosenbergii PL were observed in the mixed diet treatment with 14.37±0.51mm and 0.76±0.04mg, respectively. The specific growth rate and percentage weight gain were significantly (p < 0.05) higher in the mixed feeding treatment. However, the survival of larvae was highest (69.89±4.55%) in the Artemia nauplii treatment. The larval stage index (LSI) of M. rosenbergii larvae fed on different feeding regimes was mixed diet > Artemia nauplii > T. decipiens. The biochemical constituents of M. rosenbergii PL showed that protein concentration was higher in the larvae fed with T. decipiens, while carbohydrate and lipid content were also high in mixed feeding regimes. Results indicated that the larval stage index and growth parameters of M. rosenbergii larvae were highest in the mixed diet treatment

In order to determine the safety level of water parameters and nutrients in the natural environment of fish and freshwater prawn in Nyatuh River, Terengganu, Malaysia, it is necessary to conduct an assessment of water quality parameters. Due to its important, a study was conducted to assess the water quality parameter and nutrients contents from Nyatuh River of Setiu Terengganu in relations to the population of freshwater prawn, Macrobrachium rosenbergii caught along the Nyatuh River basin. Total of four expeditions and five stations at different tidal condition for the water quality parameter were assessed during the study. From the results achieved, the overall temperature varied between (26.56°C-29.30°C), dissolved oxygen, DO (3.59 mg/L-6.50 mg/L), pH (4.99-7.01), salinity (0.01ppt-4.22ppt), depth (2.71 m-5.54 m) while for ammonia (0.01 mg/L-0.24 mg/L), nitrite (0.01 mg/L-0.05 mg/L) and phosphate (0.01 mg/L-0.12 mg/L). While the number of prawns caught are 176, 160, 102 and 68 for Expeditions 1, 2, 4 and 3, respectively. Possibly, the heterogeneous number of prawns caught is a result of significant differences in water level depth during high tides and low tides, as well as a fluctuation in the ammonia concentration levels in each of the stations and expeditions. For statistical analysis, the temperature showed no significant difference between the expedition, stations and tidal. That is p = 0.280, p > 0.05 and F = 1.206, respectively. While dissolved oxygen, DO, showed no significant difference as well, that is p = 0.714, p > 0.05 and F = 0.737. However, the level of water depth was significantly different between expedition, station and tidal, that is p = 0.000, p < 0.05 and F = 3.120. Ammonia, on the other hand shows no significant difference between expedition, station and tidal, that is p = 0.476, p > 0.05 and F = 0.973. The same goes for nitrite and phosphate concentration. There was no significant difference between expedition, stations and tidal, that is p = 0.569, p > 0.05 and F = 0.879 and p = 0.247, p > 0.05, F = 1.255, respectively. In Expedition 1, the good water quality parameter and very low ammonia concentration resulted in a larger prawn population as compared to other expeditions. The distribution or mixture of prawns caught is heterogeneous at different stations due to the significant differences in water depth and also to the fluctuation in water quality due to varying ammonia levels. In conclusion, the water quality in Nyatuh River fluctuated across expeditions, stations, and tides, as well as significant differences in water level depths between high and low tides. Due to the rapid growth and importance of industrial and aquaculture operations along the river, extra attention should be devoted to avoid the impact of excessive pollutant in order to protect the ecosystem. [ABSTRACT FROM AUTHOR]

Tea tree oil (TTO) is an essential plant oil with diverse antibacterial and antioxidant properties; however, whether the role played by TTO in low fish meal (LF) diets induced the observed effects in the farmed crustaceans remains unclear. Therefore, this study used Macrobrachium rosenbergii as the model crustacean, and an 8-week feeding experiment with NF (normal fish meal), LF (soybean meal replacing 40% fish meal), and LFT (LF with 200 mg/kg TTO) diets was conducted to evaluate the positive effects of TTO under the LF diet. Compared to the NF diet, the LF diet reduced hemolymph antioxidant capacity and non-specific immunity, and induced hepatopancreas apoptosis and damage. However, in comparison with LF, LTF significantly ameliorated morphological impairment in the hepatopancreas, improved hepatopancreas energy metabolism by upregulating the Bcl-2/Bax and Akt/mTOR pathways, and enhanced antioxidant and non-specific immune capacity by activating the NF-κB/NO pathway. In addition, LFT repaired intestinal barrier injury and the imbalance of intestinal microbiota induced by the LF diet. Moreover, the Pearson correlation revealed the variations of the above indicators, which were related to the abundance changes of Klebsiella, Clostridium sensu stricto 12, Thermobifida, Bifidobacterium, and Alistipes, indicating that these microbes might serve as prospective targets for the intestine–hepatopancreas axis to affect hepatopancreas apoptosis, metabolism, and non-specific immunity. In summary, 200 mg/kg TTO supplementation mediated gut microbiota and positively improved energy metabolism and non-specific immunity, thereby alleviating hepatopancreas dysplasia and damage induced by the LF diet in M. rosenbergii.

This study aimed to investigate the effects of dietary tea tree oil (TTO) on the performance, intestinal antioxidant capacity, and non-specific immunity after ammonia nitrogen stress in Macrobrachium rosenbergii. Six experimental diets were formulated with 0, 25, 50, 100, 200, 400 mg/kg TTO, respectively. A total of 900 prawns (average initial weight, 0.39 ± 0.01 g) were randomly assigned to 6 groups in triplicate in 18 tanks. After an 8-week feeding trial, 20 prawns from each tank were changed with 20 mg/L ammonia stress for 24 h. The results showed that 100 mg/kg TTO significantly increased prawns performance and survival rate compared with the control group. Moreover, 100 and 200 mg/kg TTO significantly improved intestinal antioxidant capabilities by increasing SOD enzyme activities and decreasing MDA levels. In addition, the prawns fed with 100 mg/kg TTO diet showed the highest survival rate under ammonia stress. After ammonia stress, the group of 100 mg/kg TTO significantly improved antioxidant capacity by increasing hemolymph respiratory burst activity, as well as intestinal anti-superoxide anion activity and SOD. Coincidentally, 100 mg/kg TTO significantly upregulated the intestinal relative expression of antioxidant-related genes (peroxiredoxin-5). Further, it was found that 100 mg/kg TTO activated the toll-dorsal pathway in prawns, which performed the similar function as the classic NF-κB pathway by upregulating the TNF-α and IL-1. Finally, 100 mg/kg TTO increased the levels of iNOS activities and NO contents after ammonia stress and enhanced non-specific immunity. The results indicated that 100 mg/kg TTO could significantly improve the M. rosenbergii performance, antioxidant capacity and ammonia stress resistance. We suggested that the mechanisms may be attributed to that TTO enhanced the antioxidant capacity and non-specific immunity of M. rosenbergii via the NF-κB signal pathway. • Tea tree oil has the potential to improve the growth of Macrobrachium rosenbergii. • Tea tree oil can improve the survival rates of M. rosenbergii upon challenging with ammonia stress. • Tea tree oil can enhance the biochemical as well as antioxidant capacities of M. rosenbergii. • Tea tree oil increased the mRNA expression levels of immune- and antioxidant-related genes in the intestines of M. rosenbergii. [ABSTRACT FROM AUTHOR]

Highlight • The sex ratio of giant prawns in the waters of fe- male groceries is 3 times higher than that of males. • The growth characteristic of male and female giant prawns is negative allometry, but the male and female body shapes are fat. • Total mortality, capture mortality, catch rate, male prawns are higher than females. • The male infinitive growth is longer than the female,but the female's growth rate is faster than male. Abstract Giant prawns (Macrobrachium rosenbergii) is a crustacean class that has the larg- est size and its habitat in Sembakung waters included brackish water (estuarine) with a salinity variable of 6.5+0.5 ppt and a temperature variable of 28.5+0.5OC and a variable pH of 6 (acidic). The objective of this research was to analyze the growth and mortality model of giant prawns (M. rosenbergii) that was taken from the catch of fisherman in the estuary, Sembakung sub-district, Nunukan Regency, Indonesia. The study was conducted for 3 months from November 2019 to Janu- ary 2020. The sampling was by using a survey method with purposive judgment sampling based on a catch of 14 fishermen who used the bottom fish pot from Sembakung waters, Nunukan Regency (Indonesia). The data collection included data of sex, total length, and the total weight of giant prawns. While analysis was employed for growth pattern, condition index, Von Bertalanffy growth, and mor- tality. The results obtain the sex ratio of male and female giant prawns 1:3.67. The growth pattern of male and female giant prawns were allometric negative. The growth of the von Bertalanffy model for infinitive growth of male giant prawns were 21.219 cm and female were 18.42 cm, respectively the mortality from giant prawns obtain total male mortality is 2,257, catch mortality is 1.92 and natural mortality is 33.75% with an exploitation rate of 0.85 (85%). The total female mor- tality is 1.528, catch mortality is 120.1% and natural mortality is 32.69% with an exploitation rate of 0.786 (78.6%).

Superoxide dismutases (SODs) are the main antioxidant enzymes involved in alleviating oxidative stress. Although mitochondrial manganese SOD (mMnSOD) has been reported to be correlated with the immune response in crustaceans, its biological properties and role in the immune response remain unclear. Here, we cloned the Macrobrachium rosenbergii mMnSOD (Mr mMnSOD), analyzed its activity and expression pattern under Staphylococcus aureus and Vibrio parahaemolyticus infection, and further explored its possible mechanism during antibacterial immune response. The results showed that both enzyme activity and the expression of Mr mMnSOD were significantly up-regulated by bacterial infection. Mr mMnSOD knockdown made the prawn susceptible to Vibrio infection, which increased the mortality rate and the number of bacteria in haemocytes. The bacterial agglutination assay confirmed that Mr mMnSOD decreases bacterial abundance via agglutination. Overall, this work identified antibacterial function of Mr mMnSOD in the immune response. In addition to contributing to immunological theory, these findings aid disease prevention and control in crustacean aquaculture. • mMnSOD widely existed in all tested tissues in healthy M. rosenbergii. • The bacterial infection significantly up-regulated the expression of Mr mMnSOD. • Mr mMnSOD knockdown made M. rosenbergii significantly sensitive to vibriosis. • Mr mMnSOD exerted immune function via bacterial agglutination. [ABSTRACT FROM AUTHOR]

During the evolution of aquatic animals, co-evolution between host and microbes has been overlooked. Previous studies have shown that microbes were present in the fertilized egg of fish, but compared with fish, little information is available for crustaceans. High-throughput Illumina Miseq DNA sequencing of the V3-V4 domain of the 16S rRNA gene was used to assess the microbial community composition during different stages of embryonic development in Macrobrachium rosenbergii: fertilized egg stage (OM1), cleavage stage (OM2), blastula stage (OM3), gastrula stage (OM4), egg nauplius stage (OM5), egg metanauplius stage (OM6), protozoea stage (OM7) and zoea stage (OM8). Water samples (WMZ) were also assessed. The results showed that Proteobacteria (82.92%), Bacteroidetes (9.27%), and Actinobacteria (4.49%) were the predominant phylum in the M. rosenbergii embryo. At the genus level, the microbial composition was constantly changing during embryonic development. We concluded that OM3 and OM4 might be the critical stage for transformation of the microbial composition in the M. rosenbergii embryo. The main factor responsible for microbial colonization in the embryo was primarily selective pressure exerted by the shrimp, while the microbial community in the water environment had a lower impact. This study describes bacterial communities in different stages of embryonic development in M. rosenbergii, and the effects of the surrounding environment on microbial colonization. These findings provide valuable information for further studies examining the formation of early intestinal flora in crustaceans.

Sequestering of cholesterol (CHO) is a hallmark molecular event that is known to be associated with sperm gaining their fertilizing ability in a broad array of animals. We have shown previously that the level of CHO declines in the Macrobrachium rosenbergii sperm membrane when they are migrating into the vas deferens, prompting us to search for CHO transporters, one of which is Niemann–Pick type 2C (NPC2), within the prawn male reproductive tract. Sequence comparison of MrNPC2 with other NPC2, from crustaceans to mammals, revealed its conserved features in the hydrophobic cavity with 3 amino acids forming a CHO lid that is identical in all species analyzed. Expressions of MrNPC2 transcript and protein were detected in testicular supporting and interstitial cells and along the epithelial cells of the vas deferens. As confirmed by live cell staining, the testicular sperm (Tsp) surface was devoid of MrNPC2 but it first existed on the vas deferens sperm, suggesting its acquisition from the luminal fluid, possibly through trafficking of multi-lamellar vesicles during sperm transit in the vas deferens. We further showed that recombinant MrNPC2 had a high affinity towards CHO in the lipid extracts, either from Tsp or from lipid vesicles in the vas deferens. Together, our results indicated the presence of MrNPC2 in the male reproductive tract, which may play an important role as a CHO modulator between the sperm membrane and vas deferens epithelial communication. [ABSTRACT FROM AUTHOR]

To overcome the lack of immortal shrimp cell lines for shrimp viral research, we constructed and tested DNA infectious clones of Macrobrachium rosenbergii nodavirus (MrNV) and extra small virus (XSV) often found together in freshwater prawn (M. rosenbergii) exhibiting white tail disease (WTD). Full-length cDNAs of MrNV and XSV genomic RNA were individually inserted into the baculovirus pFastBacDUAL shuttle vector. Individual Sf9 (insect cell line) transfection resulted in production of RNA (RT-PCR) and capsid proteins (immunofluorescence) for both viruses. Presence of respective virions was confirmed by density gradient purification followed by RT-PCR and transmission electron microscopy. Infectivity was by tested in immersion-challenge tests with M. rosenbergii post-larvae (PL) using both semi-purified viruses, individually or combined, and confirmed by histological analysis (morphology and immunofluorescence) and quantitative RT-PCR. Mortality accompanied by WTD lesions occurred with MrNV alone or in combination with XSV but not with XSV alone, despite its replication. [ABSTRACT FROM AUTHOR]

The study was conducted to assess the growth and survival of Macrobrachium rosenbergii in earthen culture ponds in order to know about the growth potential of M. rosenbergii in mono as well as polyculture conditions in Jammu. Polyculture experiments of prawn with some selected carps Indian Major Carps (Cirrhinus mrigala and Labeo rohita) and Exotic Carps (Cyprinus carpio) were undertaken in 3 freshwater ponds for duration of 4 months. Under the monoculture conditions, prawns attained an average size of 10.40 ± 0.17 cm weighing 23.84 ± 0.32 g in 4 months and the survival rate was found to be more than 75%. The growth rate of prawns was found to increase steadily during the first half (upto mid-October) after which a decline in the growth rate was evident as the mean temperature reached below 18°C. In the polyculture ponds the prawns attained an average size of 10.10 ± 0.03 cm weighing 18.39 ± 0.89g (without C. carpio) and 8.4 ± 0.36 cm weighing 15.23 ± 0.36 g (with C. carpio) in 4 months and their survival rate was less than 70%. Prawns being benthic feeders utilized the leftover food (of the fishes) that settled at the bottom, therefore, saving the feed cost. It was observed that mean size of the fish attained in the polyculture practice was almost similar to that obtained in the monoculture. The ideal prawn polyculture should be practiced with fast growing compatible carps such as Rohu and grass carp. Bottom feeder carps such as Mrigal (C. mrigala) should be avoided in prawn polyculture practice as they compete with prawns in feeding. [ABSTRACT FROM AUTHOR]

In order to study the effects of Moringa oleifera leaf extract on Macrobrachium rosenbergii under high ammonia exposure, freshwater prawns were randomly divided into five groups: a control group was fed with basal diet, and four treatment groups fed with basal diet supplemented with 0.25%, 0.5% and 1.0% M. oleifera leaf extract and 0.025% Enrofloxacin for 60 days, respectively. Then, freshwater prawns were exposed to high ammonia stress for 72 h and Vibro anguillarum infection. The growth, antioxidant capabilities, related immune genes as well as resistance to infection by V. anguillarum were determined. The results showed that compared with the control group, the weight gain, specific growth rate and protein efficiency rate, haemolymph catalase (CAT), superoxide dismutase (SOD) and inducible nitric oxide synthase (iNOS) increased while feed conversion ratio, haemolymph aspartate aminotransferase, alanine aminotransferase, nitrogen oxide (NO), hepatopancreas heat shock proteins (HSP70), immune deficiency (IMD) expression levels decreased in the group of 0.5% M. oleifera leaf extract before the stress. After ammonia stress, the group of 0.5% M. oleifera leaf extract also could improve the haemolymph SOD, glutathione peroxidase, NO, iNOS, hepatopancreas HSP70 expression levels and reduce haemolymph CAT, hepatopancreas peroxiredoxin 5 and NF kappa B inhibitor alpha expression level compared with the control group. The rate of mortality of the prawns challenged with V. anguillarum was lower in the supplemented groups in comparison with the control group with the lowest being in the group of 0.5% M. oleifera leaf extract. Antioxidant activities as well as biochemical parameters in the enrofloxacin group (0.025%E) were not significantly enhanced both pre and post challenge in comparison with the M. oleifera leaf extract groups, showing the superiority of the natural herb over the synthetic antibiotic. In summary, this study suggested that at an inclusion rate of 0.5%, M. oleifera leaf extract could increase the growth performance, even has positive effects on physiological and immune function and prevents high ammonia stress in the Freshwater prawn, M.rosenbergii. • Moringa oleifera leaf extract has the potential to improve the growth of M. rosenbergii. • Moringa oleifera leaf extract has the potential to improve antioxidant capacities of M. rosenbergii after ammonia stress. • Moringa oleifera leaf extract improved the survival rates of M. rosenbergii after V. anguillarum and ammonia stress. • Moringa oleifera leaf extract up-regulated immune related genes of M. rosenbergii after ammonia stress. [ABSTRACT FROM AUTHOR]

Purpose: The effect of low level cobalt-60 (60Co) gamma radiation on the freshwater prawn Macrobrachium rosenbergii was evaluated by observing their hemocyte counts and biochemical parameters. Materials and methods: Prawns were exposed to 3, 30, 300 and 3000 milligray (mGy) dose levels and their tissues of gills, hepatopancreas and muscle were analyzed. Results: The results showed that the number of hemocytes in the hemolymph and concentrations of protein and carbohydrate were significantly reduced in irradiated groups than compared to the control prawn. Increased aspartate transaminase (AST), alanine transaminase (ALT), lactate dehydrogenase (LDH), alkaline phosphatase (ALP), Acetyl choline esterase (AChE) in the irradiated groups reflects tissue damage. Conclusions: Hence, this study concludes that even low level of ionizing radiation (60Co gamma) can cause acute damages in gills, hepatopancreas and muscles in irradiated groups. 60Co exposures effect the THC and biochemical of prawn M. rosenbergii. Different dose levels such as 3, 30, 300 and 3000 mGy. Biochemical parameters serve as reliable indicators of physical status of organism. Self-regulating mechanisms might be the reason for preventing from the lethality. Suggested that nuclear industries should manage below 3 mGy. [ABSTRACT FROM AUTHOR]

The present investigation was conducted to assess the suitability of three vegetable oils (sunflower oil, coconut oil and castor oil) as an alternative dietary lipid source for cod liver oil to culture Macrobrachium rosenbergii post larvae (PLs). The experimental feeds contained 40% protein with separately incorporated three vegetable oils and cod liver oil. The feeding trial was conducted on M. rosenbergii PL for 60 days. In the final day of the experimental period, the survival rate, weight gain, length gain, specific growth rate and protein efficiency ratio of prawns showed no significance (P > 0.05) between sunflower oil and cod liver oil incorporated feed fed groups. The coconut oil and castor oil showed lower performance when compared with cod liver oil. The present result showed biochemical accumulation of total protein, amino acids, carbohydrate and lipid in experimental groups. Also there is no significant difference in ash and mineral (Na+ and K+) contents. Among the tested diets, the recorded growth rate and biochemical constituents of sunflower oil and cod liver oil incorporated feed fed groups were similar. The present results revealed that the sunflower oil was on par with cod liver oil. Hence, the sunflower oil can be incorporated in feed formulation for M. rosenbergii PL culture. It can be concluded that the coconut oil and castor oil are not ideal vegetable lipid source with these concentrations which produced lower performance in survival, growth and biochemical compositions of M. rosenbergii PL.

Hemocyanin is a copper containing protein and its role in the immune function of phenoloxidase (PO) activity was investigated in the giant freshwater prawn Macrobrachium rosenbergii. Hemocyanin, sedimented by ultracentrifugation from the plasma appeared on polyacrylamide gel electrophoresis (PAGE 7%) on Coomassie Brilliant Blue and bathocuproine sulfonic acid stain as four copper containing proteins of molecular masses 50, 60, 114 and 325 kDa. Accordingly, on diethylaminoethyl-cellulose anion exchange column hemocyanin separated into four proteins designated as MrHc1, MrHc2, MrHc3 and MrHc4 with electrophoretically (PAGE) determined molecular masses of 60, 114, 50 and 325 kDa respectively. The reduction of proteins in sodium dodecyl sulphate (SDS)-PAGE revealed that MrHc1 and 3 were monomeric for 60and 50 kDa respectively, MrHc2 dimeric of 56 and 58 kDa subunits and MrHc4 appeared with three subunits of 74, 76 and 78 kDa. The PO activity was determined in plasma, hemocyanin and the four separated hemocyanin proteins in vitro using L-3,4-dihydroxyphenylalanine (L-DOPA) at pH 7.5, 25 °C and appeared elicited by exogenous activators such as trypsin, SDS, cell wall components of bacteria and polysaccharide laminarin. This study clearly demonstrated hemocyanin as the major copper containing protein in the plasma of M. rosenbergii with potent PO activity. [ABSTRACT FROM AUTHOR]

The present study was conducted to investigate the impact of adding commercial feed additives Agrimos® (combined yeast, Saccharomyces cerevisiae mannan oligosaccharides, and β-glucan) in the diet of Macrobrachium rosenbergii during the juvenile stage on growth performance, feed utilization, and immunological parameters. Four hundred and fifty juveniles of average weight 2.2 ± 0.02 g were divided into five experimental groups with three replicates each. The experiment was conducted for 56 days. Five isocaloric and isonitrogenous diets were formulated to be contain 350 g kg crude protein and 19.4 MJ GE; four diets contain different levels of Agrimos® (1.5, 2, 2.5, and 3 g kg) in addition to control diet without Agrimos®. Final body weight, weight gain, and specific growth rate of Agrimos® fed groups were significantly higher ( p < 0.05) than the control group. Survival rate of the Agrimos® fed groups and control was not significantly different ( p > 0.05). In addition, the feed conversion ratio and protein efficiency ratio in treatments supplemented by Agrimos® were significantly better ( p < 0.05) than those fed the control diet. Concerning the influence of the Agrimos® on proximate composition of carcass, no significant differences ( p > 0.05) were observed among different treatments. Increased immune response was observed in experimental groups with the 2.5 g kg Agrimos® concentration yielding the significantly higher ( p < 0.05) total hemocyte count and phenoloxidase. In conclusion, the additions of Agrimos® in the diet 3 at a concentration of 2.5 g kg improved and enhanced the growth performance and feed utilization of M. rosenbergii juveniles. [ABSTRACT FROM AUTHOR]

In order to determine the safety level of water parameters and nutrients in the natural environment of fish and freshwater prawn in Nyatuh River, Terengganu, Malaysia, it is necessary to conduct an assessment of water quality parameters. Due to its important, a study was conducted to assess the water quality parameter and nutrients contents from Nyatuh River of Setiu Terengganu in relations to the population of freshwater prawn, Macrobrachium rosenbergii caught along the Nyatuh River basin. Total of four expeditions and five stations at different tidal condition for the water quality parameter were assessed during the study. From the results achieved, the overall temperature varied between (26.56°C-29.30°C), dissolved oxygen, DO (3.59 mg/L-6.50 mg/L), pH (4.99-7.01), salinity (0.01ppt-4.22ppt), depth (2.71 m-5.54 m) while for ammonia (0.01 mg/L-0.24 mg/L), nitrite (0.01 mg/L-0.05 mg/L) and phosphate (0.01 mg/L-0.12 mg/L). While the number of prawns caught are 176, 160, 102 and 68 for Expeditions 1, 2, 4 and 3, respectively. Possibly, the heterogeneous number of prawns caught is a result of significant differences in water level depth during high tides and low tides, as well as a fluctuation in the ammonia concentration levels in each of the stations and expeditions. For statistical analysis, the temperature showed no significant difference between the expedition, stations and tidal. That is p = 0.280, p > 0.05 and F = 1.206, respectively. While dissolved oxygen, DO, showed no significant difference as well, that is p = 0.714, p > 0.05 and F = 0.737. However, the level of water depth was significantly different between expedition, station and tidal, that is p = 0.000, p < 0.05 and F = 3.120. Ammonia, on the other hand shows no significant difference between expedition, station and tidal, that is p = 0.476, p > 0.05 and F = 0.973. The same goes for nitrite and phosphate concentration. There was no significant difference between expedition, stations and tidal, that is p = 0.569, p > 0.05 and F = 0.879 and p = 0.247, p > 0.05, F = 1.255, respectively. In Expedition 1, the good water quality parameter and very low ammonia concentration resulted in a larger prawn population as compared to other expeditions. The distribution or mixture of prawns caught is heterogeneous at different stations due to the significant differences in water depth and also to the fluctuation in water quality due to varying ammonia levels. In conclusion, the water quality in Nyatuh River fluctuated across expeditions, stations, and tides, as well as significant differences in water level depths between high and low tides. Due to the rapid growth and importance of industrial and aquaculture operations along the river, extra attention should be devoted to avoid the impact of excessive pollutant in order to protect the ecosystem., (© Penerbit Universiti Sains Malaysia, 2023.)

C-type lectins (CTLs) play important roles in the innate immunity of invertebrates. In this study, a novel CTL with a single carbohydrate recognition domain (CRD) containing an EPN (Glu-Pro-Asn) motif was identified from the giant freshwater prawn Macrobrachium rosenbergii . This CTL was designated as MrCTL . The cDNA of MrCTL is 1788 bp with a 657 bp open reading frame that encodes a protein of 218 amino acids. The cDNA and genome sequences of MrCTL show a polymorphism that leads to MrCTL isoforms. MrCTL was highly expressed in the gills and intestine of normal prawn, and its transcription increased after Vibrio parahaemolyticus or white spot syndrome virus (WSSV) challenge. Recombinant mature MrCTL and its single CRD could agglutinate (Ca 2+ -dependent) and bind both Gram-positive and Gram-negative bacteria. The recombinant proteins could attach to lipopolysaccharide and peptidoglycan in a dose-dependent manner. Recombinant MrCTL could accelerate bacterial clearance. Thus, MrCTL could serve as a pattern recognition receptor involved in the innate immunity of M. rosenbergii . [ABSTRACT FROM AUTHOR]

Sperm maturation taking place in male accessory tracts is a complex series of biomolecular dynamics of both lipids and proteins on sperm plasma membrane. In this study, we compared fatty acid (FA) compositions on a single banded phophatidylcholine (PC) in Macrobrachium rosenbergii sperm collected from testis (Tsp) and vas deferens (Vsp) to give an insight of membrane lipid dynamic during sperm maturation. Saturated (SAT, predominantly C16:0) and monounsaturated fatty acids (MUFA, predominantly C18:1, n 9) were apparently higher in Vsp whereas the polyunsaturated fatty acids (PUFA, mainly C20:5, n 3 and C22:6, n 3) were evidently lower. Higher level of PUFA in the Vsp was also supported by merocyanine staining followed by flow cytometric analysis. Imaging mass spectroscopy (IMS) gave both comparative and quantitative data of the paired FA within an intact PC molecule while it also provided FA distribution within the PC band. The levels of lipids, particularly cholesterol (CHO) and sphingomyelin (SM), as well as PUFA and other FA species in the spermatic vesicles (SV) were found to be opposite to those of Vsp. We thus believe that an alteration of lipid compositions in sperm membrane is partly modulated via SV transport in vas deferens, which is considerable a part of sperm maturation process in M. rosenbergii , similar to that reported for mammalian epididymal sperm maturation. Statement of relevance This work will provide an insight of lipid dynamics on sperm plasma membrane which relates to a part of sperm maturation process. Nutritional management with the known fatty acid compositions of mature sperm would help to improve sperm quality for practical aquaculture. [ABSTRACT FROM AUTHOR]

Macrobrachium rosenbergii, known as the giant freshwater prawn or Malaysian prawn, is the sixth largest aquaculture species in Asia. Knowledge of genetic diversity of M. rosenbergii is important to support management and conservation programmes, which will subsequently help in sustainable production of this economically important species. This study aimed to analyse the genetic diversity and population structure of five M. rosenbergii populations using 11 microsatellite loci. In analysing 240 samples, the number of alleles, observed heterozygosity (HO) and expected heterozygosity (HE) ranged from 3 to 20, from 0.250 to 0.978 and from 0.556 to 0.944 respectively. The five stocks of M. rosenbergii displayed high level of genetic diversity. Both the FST and amova analyses showed that there was significant genetic differentiation among all populations. The UPGMA dendrogram based on Nei's genetic distance matrix revealed that the Narmada and Mahi populations were in one cluster and Mahanadi and Subarnarekha populations in another single major branch, whereas the Kerala population clearly showed a separate cluster. This information on genetic variation will be useful for genetic improvement and conservation of Indian populations of giant freshwater prawn M. rosenbergii. [ABSTRACT FROM AUTHOR]

Se evaluó la eficiencia nutrimental de un producto semi húmedo “Flan de calamar”, como suplemento y/o complemento alimenticio para larvas de langostino Macrobrachium rosenbergii a partir del V estadio de vida. El alimento se formuló con calamar fresco y huevo de gallina (38.8% proteína cruda, y 16.4% lípidos totales) como fuentes proteicas. Se probaron tres dietas experimentales con tres repeticiones en un diseño completamente aleatorio y una densidad de 50 larvas L-1 (2500 larvas/unidad experimental). Los tratamientos fueron: A1 : Nauplios de Artemia sp. recién eclosionados; A2 : 50% de nauplios de Artemia sp. y 50% de flan de calamar; A3 : Únicamente flan de calamar. Las larvas fueron alimentadas dos veces al día (8:00 y 14:00). El estudio se realizó en nueve tinas circulares plásticas (62 L), en un sistema abierto de cultivo y una salinidad de 14 ± 2 g L-1. temperatura 29 ± 0.5 oC y fotoperiodo 12:12 L:O. En el tratamiento A2, se observaron las primeras postlarvas después de 23 d de cultivo, mientras que en A1 y A3 entre los días 24 y 25. Con el tratamiento A2 se obtuvo una producción de postlarvas y supervivencia significativa-mente superior (91.5%) al de A1 y A3, que no presentaron diferencias entre si. Los resultados indican que el “Flan de Calamar” puede usarse como suplemento parcial de nauplios de Artemia sp. durante la producción de postlarvas de M. rosenbergii. La dieta experimental además de ser sencilla de preparar, presenta alta calidad nutrimental y estabilidad en el agua.

Unless better measures are put in place to address the environmental and social impacts emanating from the huge waste generated from sea food processing industries; 'tragedy of the commons' is inevitable. Needless to re-emphasise the enormous contributions of aquaculture as the perfect substitute to capture fisheries which has been proven unsustainable. Be that as it may, the huge amount of bio-waste produced could be transformed into useful products such as chitin and chitosan with far reaching applications. Chitin and chitosan have been consistently processed from many sources following the traditional chemical sequence of Demineralization (DM), Deproteinization (DP), Decolouration (DC) and Deacetylation (DA). In this study, this method was re-ordered, resulting to 4 sequences of chemical processes. HCl, NaOH, ethanol (97%) and NaOH (50%) were used for DM, DP, DC and DA respectively. The results of this study showed that better chitin (23.99 ± 0.61%) and chitosan (15.17 ± 1.69%) yields were obtained from sequence four (SQ4) following the order of DC-DM-DP-DA. In addition, physicochemical properties such as DDA (80.67 ± 2.52%) and solubility (66.43 ± 2.61%) were significantly higher (p ≤ 0.05) in SQ4 thereby making the obtained product suitable for use as coagulant and flocculant in wastewater treatment. Results of FTIR, XRD and SEM of the study proved that the resultant product exhibited the characteristic nature of chitosan with porous and fibril nature. In the analysis of the physical properties of chitosan obtained from bio-waste of Macrobrachium rosenbergii , the high Carr's index (CI) and low bulk as well as tapped densities were an indication that the chitosan produced in this study had poor flowability and compressibility, thereby making it unfit for application in pharmaceutical industries., Competing Interests: The authors declare no competing interest, (© 2023 The Authors.)

Macrobrachium rosenbergii juveniles (0.34 ± 0.01 g) were fed with β-glucan-incorporated diets at levels 0.0, 1.0, 2.0 and 3.0 g kg diet. After 60 days of feeding trial, immune response and resistance to Aeromonas hydrophila were studied. Immune parameters, namely prophenol oxidase, super anion production, total hemolymph protein and total hemocyte count, were found significantly different ( p < 0.05) in 1.0 g kg β-glucan-incorporated diet. The relative percentage survival was observed significantly higher ( p < 0.05) in 1.0 g kg β-glucan inclusion level, after challenged against A. hydrophila. These results indicated that dietary level of β-glucan at 1.0 g kg could enhance immune responses and resistance to A. hydrophila in M. rosenbergii. [ABSTRACT FROM AUTHOR]

The present investigation was conducted to assess the suitability of three vegetable oils (sunflower oil, coconut oil and castor oil) as an alternative dietary lipid source for cod liver oil to culture Macrobrachium rosenbergii post larvae (PLs). The experimental feeds contained 40% protein with separately incorporated three vegetable oils and cod liver oil. The feeding trial was conducted on M. rosenbergii PL for 60 days. In the final day of the experimental period, the survival rate, weight gain, length gain, specific growth rate and protein efficiency ratio of prawns showed no significance ( P > 0.05) between sunflower oil and cod liver oil incorporated feed fed groups. The coconut oil and castor oil showed lower performance when compared with cod liver oil. The present result showed biochemical accumulation of total protein, amino acids, carbohydrate and lipid in experimental groups. Also there is no significant difference in ash and mineral (Na + and K + ) contents. Among the tested diets, the recorded growth rate and biochemical constituents of sunflower oil and cod liver oil incorporated feed fed groups were similar. The present results revealed that the sunflower oil was on par with cod liver oil. Hence, the sunflower oil can be incorporated in feed formulation for M. rosenbergii PL culture. It can be concluded that the coconut oil and castor oil are not ideal vegetable lipid source with these concentrations which produced lower performance in survival, growth and biochemical compositions of M. rosenbergii PL. [ABSTRACT FROM AUTHOR]

This experiment was carried out to investigate the potential probiotics properties of Bacillus subtilis in protecting of juvenile freshwater prawn, Macrobrachium rosenbergii against Aeromonas hydrophila infection. A B. subtilis bacterium isolated from gut of juvenile prawns was added to the prawns feed at 10 cells g feed. There were significant differences ( P < 0.05) between B. subtilis-treated and control groups in growth and survival enhancement of juvenile prawns after 60 days of feeding trial. Sixty days after B. subtilis feeding trial, the prawns were challenged by bath exposure to A. hydrophila (10 cells mL) for 28 days. Four weeks after challenge, there was significant difference in the survival of prawns between B. subtilis-treated groups (88.33 %) and control groups (20.81 %; P < 0.05). In addition, the control groups had an unhealthy external appearance, while the treated groups, appeared healthy and normal. From this, it was concluded that the selected B. subtilis may be a promising probiotics for protection of prawns from A. hydrophila infection. [ABSTRACT FROM AUTHOR]

Expressed sequence tags (EST) provide a valuable and cost effective source of developing simple sequence repeat (SSR) markers. In the present study, genic microsatellite markers were developed for Macrobrachium rosenbergii through mining of EST databases. Twenty-three polymorphic EST-SSR loci were found with number of alleles ranging from 3 to 10, observed and expected heterozygosity per locus ranged from 0.1481 to 0.9565 and from 0.2655 to 0.8741, respectively. Of these SSRs, 7 showed significant homology to known genes by BLASTx (basic local alignment search tool x) search. In cross-species amplification, out of 23 polymorphic loci, there were 21 positive amplifications in M. malcolmsonii, 22 in M. gangeticum and 18 in M. lamarrei. These new EST-SSR markers will be useful for genetic studies and genome mapping of M. rosenbergii and closely related macrobrachium species. [ABSTRACT FROM AUTHOR]

Abstract: This experiment was carried out to evaluate the effects of the probiotic Bacillus subtilis on survival, growth, biochemical constituents and energy utilization in Macrobrachium rosenbergii PL. Experimental diets were the same in all, except for the variation in probiotic levels. The probiotic B. subtilis was used at 0% (diet 1), 1% (diet 2), 2.0% (diet 3), 3.0% (diet 4) and 4.0% (diet 5) inclusion in the experimental diets. These diets were fed to M. rosenbergii PL for a period of 90days. The growth parameters, such as survival, weight gain, specific growth rate, feed conversion efficiency and protein efficiency rate were significantly (P <0.05) higher in 3% B. subtilis incorporated diet fed PL followed by other experimental groups than the control. Similarly the biochemical constituents of the protein, amino acid, carbohydrate, lipid and ash content were significantly (P <0.05) higher in 3% B. subtilis incorporated diet fed PL. The energy utilization parameters, such as feeding rate, absorption rate, conversion rate and metabolic rate were significantly (P <0.05) higher in 3% B. subtilis incorporated diet fed PL. From the results of this experiment, we conclude that B. subtilis can be used as a probiotic in M. rosenbergii culture, to enhance the survival, growth and improved energy utilization performance. [Copyright &y& Elsevier]

Anti-lipopolysaccharide factors (ALFs) are a group of effector molecules that are classified as antimicrobial peptides (AMPs). They are found in limulids and crustaceans and show a broad range of antimicrobial activity. In the current study, an ALF gene from Macrobrachium rosenbergii ( MrALF) was identified. Its full length was 690 bp and it encoded a 124 amino acid protein. A signal peptide and a conserved LPS-binding domain with two conserved cysteine residues that comprise a cluster of positive charged residues within a disulfide loop were predicted in MrALF. The M. rosenbergii ALF clusters with the Macrobrachium olfersii ALF and further clusters with most crustacean ALFs, suggesting that they should originate from one common ancestor. Positive selections should have sharpen the evolution of M. rosenbergii and M. olfersii ALF genes. Reverse transcriptase polymerase chain reaction analysis showed that MrALF was expressed in all detected tissues. In the epidermis, MrALF was obviously upregulated 24 h after the LPS challenge. In the stomach and gills, MrALF was upregulated upon LPS challenge. The results show that MrALF might have important roles in the immune defense against invading bacteria. The positive selections that occur in the ALFs of crustaceans might have resulted from a Red Queen's race with its pathogens. We found evidence of positive selection acting to drive functional divergence during the evolution crustacean ALF genes, especially in the M. rosenbergii ALF gene. The evolutionary changes might correspond to the challenges induced by pathogens that infect crustaceans. [ABSTRACT FROM AUTHOR]

Infectious hypodermal and haematopoietic necrosis virus (IHHNV) has been detected widely in penaeid culture facilities in Asia and the Americas. IHHNV infection on sub-adult and postlarvae of the giant freshwater prawn, Macrobrachium rosenbergii which had caused up to 80% mortalities was first reported in Southeast Taiwan in 2006. In Malaysia, although, there has been no report on IHHNV infections in M. rosenbergii, preliminary work suggests that there is an urgent need to setup a screening protocol for IHHNV for both wild and cultured populations. In this study, polymerase chain reaction based screening was carried out on 30 randomly sampled berried wild M. rosenbergii before and after spawning. All samples did not showed any sign of IHHNV infection. However, the results showed that 20% of the samples were IHHNV positive. Sequence analysis of the amplified band using NCBI-BLAST showed that the putative IHHNV sequence had 98% nucleotide sequence (388 bp) identity with the IHHNV isolate AC-05-005 non-structural protein 1 gene and seven other IHHNV strains in the data bank further affirming the suggestion on the presence of IHHNV in wild freshwater prawn populations in Malaysia. [ABSTRACT FROM AUTHOR]

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Eight hundred and eighty-five strains of bacterial isolates from various samples associated with the natural habitat of Macrobrachium rosenbergii were screened for their probiotic potential. Two putative probionts namely Bacillus NL110 and Vibrio NE17 isolated from the larvae and egg samples, respectively, were selected for experimental studies and were introduced to the juveniles of M. rosenbergii (0.080±0.001 g) through different modes such as through feed, water and both. The probiotic potential of the above bacteria in terms of improvements in water quality, growth, survival, specific growth rate (SGR), feed conversion ratio and immune parameters was evaluated. The treatment groups showed a significant improvement in SGR and weight gain ( P<0.001). Survival among different treatment groups was better than that in the control group. There were also significant improvements in the water quality parameters such as the concentration of nitrate and ammonia in the treatment groups ( P<0.05). Improvements in immune parameters such as the total haemocyte count ( P<0.05), phenoloxidase activity and respiratory burst were also significant ( P<0.001). It is concluded that screening of the natural microflora of cultured fish and shellfish for putative probionts might yield probiotic strains of bacteria that could be utilized for an environment-friendly and organic mode of aquaculture. [ABSTRACT FROM AUTHOR]

Abstract: In order to study the effects of anthraquinone extract from Rheum officinale Bail on Macrobrachium rosenbergii under high temperature stress, freshwater prawns were randomly divided into five groups: a control group was fed with basal diet, and four treatment groups fed with basal diet supplemented with 0.05%, 0.1%, 0.2%, and 0.4% anthraquinone extracts for 10 weeks, respectively. Then, freshwater prawns were exposed to high temperature stress at 35°C for 48h. The growth, changes in haemolymph total protein, aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), lysozyme, nitrogen monoxide (NO) and hepatic catalase (CAT), superoxide dismutase (SOD) and malondialdehyde (MDA) were investigated. The results showed that compared the control group, the specific growth rates, feed conversion efficiency, haemolymph ALP and lysozyme activities, total protein contents, hepatic CAT and SOD activities increased while haemolymph AST, ALT and hepatic MDA contents decreased in treatment groups before the stress, but their levels did not correlate with the doses of anthraquinone extracts. The specific growth rate (SGR), feed conversion efficiency and haemolymph lysozyme activity significantly increased but haemolymph AST activity decreased in 0.1% dose group; whereas haemolymph ALP activity and feed conversion efficiency increased but ALT activity and hepatic MDA contents significantly decreased in 0.2% dose group before the stress compared with the control. After high temperature stress, 0.1–0.2% anthraquinone extract also could improve the haemolymph total proteins, lysozyme and ALP activities, hepatic catalase, and superoxide dismutase, and reduce haemolymph ALT and AST activities, hepatic malondialdehyde contents. The cumulative mortality in the control was about 100% at 48h after high temperature stress while the cumulative mortality in the treatment groups supplemented with 0.1–0.2% anthraquinone extract were about 48–65%. The artificial infection with Vibrio anguillarum also showed the cumulative mortality in the control was about 100% while the cumulative mortality in the treatment groups supplemented with 0.1–0.2% anthraquinone extracts were about 57–80%. The present study suggested that ingestion of a basal diet supplemented with 0.1–0.20% anthraquinone extracts could prevent high temperature stress and promote the growth of prawns. [Copyright &y& Elsevier]

Abstract: A combination of eugenol and menthol was tested for mitigating handling stress of adult Macrobrachium rosenbergii. Prawns were first exposed to four different doses (100, 200, 400 and 800µLL−1) of eugenol and menthol; both individually and in combination. The dose at which induction and recovery time less than 30min was regarded as the critical dose. It was demonstrated that 200µLL−1 dose was sufficient for induction, recovery and significantly (p <0.05) lower oxygen consumption rate. Further, metabolic responses [glucose, lactate dehydrogenase (LDH), malate dehydrogenase (MDH), alanine amino transferase (ALT) of M. rosenbergii were higher when exposed to 30min handling stress alone (T1), over (T2) when exposed to stress in the presence of the anesthetic mixture. Lower levels of glycogen and acetylcholine esterase (AchE)] were observed in T1 over T2, indicating secondary metabolic responses to cope up with the stress due to handling. A control (without handling stress and sampling without anesthetic exposure) was maintained to compare the effect of handling stress. In order to ensure its margin of safety, accumulation and clearance of the anesthetic residues were tested from the muscle of M. rosenbergii, which indicated that eugenol and menthol accumulate in tissues of M. rosenbergii. However, 24h purging protocol cleared the residues completely from the tissues of M. rosenbergii. Overall results indicate that eugenol and menthol based anesthetic formulation is safe and effective for handling of adult M. rosenbergii. [Copyright &y& Elsevier]

An experiment was conducted from December 2003 to April 2004 to observe the over-wintering growth of freshwater prawn, Macrobrachium rosenbergii, with catla, Catla catla and rohu, Labeo rohita in polyculture using formulated diets. The study was conducted in eight experimental ponds, each 80 m2. Three experimental diets containing 30% protein were prepared using fish meal, meat and bone meal, mustard oilcake, rice bran, wheat bran and molasses (binder), and assigned to treatments T1, T2 and T3 respectively. A commercial diet from Saudi-Bangla Fish Feed was assigned to T4 (reference diet). Each treatment had two replicate ponds. Juvenile prawns and catla and rohu fingerlings (initial weight 1.60±0.10, 30.0±1.2 and 25.0±1.1 g respectively) were stocked at a ratio of 2:1:1 (prawn:catla:rohu). A total of 160 prawn and fish (20 000 ha−1) were stocked in each pond. Fish were fed twice daily at 3% body weight (b.w.) for the first 3 months and 5% b.w. for the last 2 months. Prawns in T1 fed diet 1 had significantly higher ( P<0.05) weight gain compared with that of T3. The reference group and T2 had intermediate values not significantly different from either. Weight gains of catla and rohu were significantly higher in T1. The feed conversion ratio values of different diets ranged between 1.89 and 2.13. Survival (%) ranged from 90.0% to 95.0% for catla, 87.5% to 92.5% for rohu and 70.0% to 76.3% for M. rosenbergii, and there were no significant differences ( P>0.05) among different treatments. Total production ranged between 2196 and 2679 kg ha−1, with T1 showing significantly higher production and net profit (taka 56 531.9 ha−1). The results of the study demonstrated that it is possible to culture M. rosenbergii with carp in polyculture during the winter utilizing the late-produced PLs. Further study is needed to determine the optimum stocking density of M. rosenbergii in carp polyculture. [ABSTRACT FROM AUTHOR]

Abstract: An in vivo study was conducted to assess effect of incubation temperature on embryonic development and hatching period of freshwater prawn (Macrobrachium rosenbergii). Brooders spawned on a single day were distributed among four temperature treatments, each with six replicates, and acclimated at a rate of 1°C/day above and below ambient water temperature (30°C) to reach test temperatures (25, 29, 33 and 36°C) and maintained in separate rearing conditions until hatch. Sampling of developing embryos was done at 24-h intervals until mortality/hatching and observed under a light microscope. Major half axis, minor half axis, area and perimeter were measured at 48-h intervals. Embryonic development rates increased with increasing temperatures [y (time from early morula hatch; h)=40.075x (temperature; °C)+348.75; R 2 =0.993). A rapid increase in major half axis, larval length, and faster hatching correlated with higher temperatures. Hence this study revealed that incubation temperature significantly influences the time to and duration of hatching and survival of M. rosenbergii eggs. [Copyright &y& Elsevier]

The objective of this study was to determine the microbiological quality of farmed giant freshwater prawn (Macrobrachium rosenbergii) collected from four freshwater farms located in Kerala (India). Microbiological counts on whole, deheaded, and deheaded and deveined prawn as well as on head and intestine were determined. Average counts (log10 cfu g-¹) on whole prawn were 6.9 (total mesophilic counts (TPC) at 37°C) and 4.1 (psychrotrophic count at 7°C). The results indicated that the aerobic counts were within the acceptable limit. The levels of enterococci and faecal coliforms in farmed M. rosenbergii were high. There was an increase in the numbers of enterococci and Staphylo- coccus aureus after deheading. The major groups of bacteria comprising the flora of M. rosenbergii were Aeromonadaceae, Enterobacteriaceae and Pseudo,nonas. Farmed M. rosenbergii carried pathogenic bacteria such as Enterococcus spp., S. aureus, Aeromonas hydrophila, A. veronii biovar sobria and Clostridium perfringens. The results of the study sug- gest adoption of good farming and post harvest practices to improve the microbiological quality of farmed freshwater prawn. [Article copies available [ABSTRACT FROM AUTHOR]

Egg quality parameters of two Macrobrachium species (M. rosenbergii and M. tenellum) were evaluated testing three brood stock diets. The experimental diets were as follows: a) 100% natural food, b) natural food complemented with a commercial peletized diet plus Artemia biomass boosted with a commercial lipid emulsion, and c) a domestic peletized diet. Despite the differences in protein content of the diets, there were no significant differences (P > 0.05) in the number of spawnings among diets, egg number, egg dry weight and egg volume for M. tenellum. For M. rosenbergii, differences (P < 0.05) were only detected in the number of eggs per spawning, registering the highest amount for the control diet (33,978). Differences between the two species for all the quality parameters were based in the female size variation. Due to the egg eliptic-shape, it is suggested the study of the egg volume as a reliable quality parameter instead of its the diameter. [ABSTRACT FROM AUTHOR]

The freshwater prawn, Macrobrachium rosenbergii, commonly called 'scampi,' is the most important culturable freshwater species of prawn with a fairly high growth rate, wide range of temperature (15-35°C) and salinity tolerance. The nutrients required by this species for growth and associated physiological functions are similar to those required by other crustaceans. Current data suggest that a digestible protein level of above 30% is required for maximum growth and protein efficiency. Ingredients such as mussel meat meal, squid meal, and shrimp meal serve as potential sources of protein in formulated diets. The complete quantitative requirements for all the essential amino acids for this prawn species have not yet been worked out. With respect to non-protein energy supply in the form of carbohydrate, studies indicated that scampi is capable of utilizing various carbohydrate sources efficiently. Dietary carbohydrate in the form of complex polysaccharides appears to be more effective as an energy source. Like other crustaceans, scampi also has limited ability to synthesize sterol from acetate and mevalonic acid. Quantitative estimates of the essential fatty acid require-ments have been made in post-larval scampi. Data on vitamin and mineral requirements are scarce. Recent developments in diet formulation, practical feeding practices and the aquaculture potential in India have been indicated with emphasis on sustainable production. [ABSTRACT FROM PUBLISHER]

An excess of reactive oxygen species (ROS) usually disrupts the balance of the antioxidant system and impairs the homeostasis of cells, resulting in serious oxidative damage. Therefore, a better understanding of how the immune system protects itself against such excessive oxidative stress is crucial. SODs play an indispensable role in antioxidant defense and the innate immune system. Among those, MnSOD is one of the most being. Previous studies using crustaceans have focused much on the gene expression changes underlying pathogenic infections, which generally indicate that MnSOD is involved in the antibacterial immune process of crustaceans. Yet the detailed biological properties of MnSOD and mechanism by which it counters pathogen infection in Macrobrachium rosenbergii remain unclear. Here we first cloned the cytosolic MnSOD from M. rosenbergii (Mr cMnSOD), and then analyzed its distribution in tissues and expression patterns under bacterial infection with Staphylococcus aureus and Vibrio parahaemolyticus. The results revealed Mr cMnSOD widely distributed in the tested tissues, whose expression level was highest in the hepatopancreas, followed by the stomach and intestine. Infection with S. aureus and V. parahaemolyticus significantly up-regulated both total SOD activity and transcription level of Mr cMnSOD. To further investigate the possible mechanism of Mr cMnSOD's participation in that antibacterial immune response, an RNA knockdown assay in vivo was performed. After knocking down Mr cMn SOD , a higher mortality rate and more residual bacteria in haemocytes were recorded than for control group. Furthermore, an in vitro bacterial agglutination assay of Mr cMnSOD demonstrated Mr cMnSOD harbors broad bacterial agglutination to both gram-negative and gram-positive bacteria. Overall, our findings strongly suggest that Mr cMnSOD is only capable of modulating the host's redox state but also exerting an antibacterial function in M. rosenbergii , thus shedding new light on the immune functioning of Mr cMnSOD in crustaceans. Importantly, this work provides a new perspective for disease prevention and control in farmed crustaceans. • cMnSOD widely existed in all tested tissues in healthy M. rosenbergii. • The bacterial infection significantly up-regulated the expression of Mr cMnSOD. • Mr cMnSOD knockdown made M. rosenbergii significantly sensitive to vibriosis. • Mr cMnSOD exerted immune function via bacterial agglutination. [ABSTRACT FROM AUTHOR]

The present study was designed to evaluate the effect of acute level of 60 Co gamma radiation on fecundity of freshwater prawn Macrobrachium rosenbergii . Prawns were exposed to four different dose levels (3, 30, 300 and 3000 mGy) and their reproductive disturbances i.e Gonadosomatic Index (GSI), Egg Clutch somatic Index (ESI), Egg Counts and Egg hatching rates were calculated. The experimental group showed significant reduction in GSI (0.47 ± 0.01) & ESI (1.22 ± 0.08) after exposure to 60 Co gamma radiation. Egg Count (3713 ± 21) and Egg hatching rates (3798 ± 11) were significantly reduced in all irradiated groups. The number of dead larva increased with the increasing level of doses. With the increase in dosage level, the gonad and egg clutch weight were decreased which likely lead to reduced number of eggs. Our results proved that even low level of ionizing radiation ( 60 Co) affects the fecundities of freshwater crustacean M. rosenbergii ., Competing Interests: The authors declare no conflict of interest., (© 2019 The Authors.)