Advertisement
Browse Subject Areas
?

Click through the PLOS taxonomy to find articles in your field.

For more information about PLOS Subject Areas, click here.

  • Loading metrics

Open Access

Peer-reviewed

Research Article

Influence of salinity on growth, nutrient utilization, and gene expression of giant freshwater prawn (Macrobrachium rosenbergii)

  • Farhana Ahamed Shanila ,

    Roles Data curation, Formal analysis, Methodology

    ☯ Contributed equally to this study.

    Affiliation Department of Aquaculture, Faculty of Fisheries, Patuakhali Science and Technology University, Patuakhali, Bangladesh

    ⨯
  • Md. Rajib Sharker ,

    Roles Data curation, Formal analysis, Investigation, Methodology, Writing – original draft

    ☯ Contributed equally to this study.

    Affiliation Department of Fisheries Biology and Genetics, Faculty of Fisheries, Patuakhali Science and Technology University, Patuakhali, Bangladesh

    ⨯
  • Md. Rafiqul Islam,

    Roles Data curation, Formal analysis, Methodology

    Affiliation Department of Aquaculture, Faculty of Fisheries, Patuakhali Science and Technology University, Patuakhali, Bangladesh

    ⨯
  • Niels O. G. Jørgensen,

    Roles Validation, Visualization, Writing – review & editing

    Affiliation Department of Plant and Environmental Sciences, University of Copenhagen, Frederiksberg, Denmark

    ⨯
  • Mohammad Lokman Ali

    Roles Conceptualization, Methodology, Supervision, Writing – original draft

    lokman.fri@gmail.com

    Affiliation Department of Aquaculture, Faculty of Fisheries, Patuakhali Science and Technology University, Patuakhali, Bangladesh

    ⨯

Abstract

Salinity is one of the most influential eco-hydrological factors that affect the molting, growth, and other physico-biochemical responses of crustaceans. A 56-day in vivo experiment was conducted to assess the effects of variable salinities on growth attributes, feed utilization, and gene expression profile of Macrobrachium rosenbergii. Juveniles of M. rosenbergii that were exposed to salinities of 0, 3, 6, 9, and 12 ppt in triplicate, and designated as control, T1, T2, T3, and T4, respectively. Higher weight gain (WG), %WG, specific growth rate (SGR), feed conversion ratio (FCR), and protein efficiency ratio (PER) were recorded at 3 ppt than at other salinities. A salinity of 3 ppt also showed higher values of condition factor (CF), and survival of M. rosenbergii. A polynomial regression analysis indicated that the optimal salinity for WG and SGR of M. rosenbergii were 3.12 and 3.80, respectively. A significant decrease in the molt-inhibiting hormone (MIH) and an increase in the chitinase (CHIT) gene expression were documented at 3 ppt compared to control. The mRNA transcripts of stress response genes were significantly downregulated, and immune-related genes were upregulated at 3 ppt salinity, compared to the other salinities. Although the expression of antioxidant-related genes was upregulated when rearing at 3 ppt salinity, no significant differences were found relative to other salinities. Our findings suggest that M. rosenbergii reared at 3 ppt salinity show promising improvements in growth attributes by modulating the expression profile of physico-biochemical response genes reared at low temperature.

Citation: Shanila FA, Sharker MR, Islam MR, Jørgensen NOG, Ali ML (2026) Influence of salinity on growth, nutrient utilization, and gene expression of giant freshwater prawn (Macrobrachium rosenbergii). PLoS One 21(7): e0353240. https://doi.org/10.1371/journal.pone.0353240

Editor: Gao-Feng Qiu, Shanghai Ocean University, CHINA

Received: March 10, 2026; Accepted: June 19, 2026; Published: July 23, 2026

Copyright: © 2026 Shanila et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Data Availability: All relevant data are within the paper.

Funding: This research received financial support from the Danish International Development Agency (DANIDA) for the project “Climate-Friendly and Climate-Resilient Prawn Farming in Bangladesh (ECOPRAWN)”, Grant No. DFC File No. 21-01-KU. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

Competing interests: The authors have declared that no competing interests exist.

1. Introduction

Salinity is one of the key environmental variables influencing growth, reproduction, survival, and distribution of aquatic invertebrates [1,2]. Although many crustaceans exhibit a wide tolerance to salinity fluctuations, the optimal salinity range for individual species is specific, varying with physiological adaptations and ecological requirements [3–5]. In recent years, climate variability has caused rising sea levels, coastal flooding, and intensified tropical cyclones, leading to salinity-induced water stress in freshwater fisheries in various regions of the world [6]. In freshwater species, salinity fluctuations affect the physiology, reproductive performance, abundance, and distribution [7–9]. Salinity also has a strong influence on embryonic and larval development, growth, and production of aquaculture species [10,11]. In aquaculture, salinization of the water has a major impact on the sustainability of the production by modifying the feed utilization, metabolic activity, immune performance and survival of farmed species [12–14]. Saltwater intrusion during flooding in southern Bangladesh raises salinity levels in shallow prawn farms, causing stress, reduced growth, and high mortality in freshwater prawn M. rosenbergii [15].

Among aquatic crustaceans, several species have been documented to rear in inland saline waters across various parts of the globe [16,17]. Salinity intrusion poses a significant challenge to freshwater aquaculture due to severe physiological stress that might eventually lead to their extinction due to inability to adapt such harsh condition. Thus, it is crucial to determine the optimal salinity level for economically significant prawn species in aqua-farming systems, where salinity can be adjusted to suit the species growth, survival, and overall productivity.

Globally, the giant freshwater prawn (M. rosenbergii) is an economically significant crustacean species owing to its fast growth and tolerance to various environmental stressors, as well as disease resistance, delicate carcass quality, and high market value compared to other shellfish species [18]. M. rosenbergii is rich in proteins, essential amino acids, and polyunsaturated fatty acids, while being low in fat, making this prawn a cherished and nutritious food preference for human consumption [19]. M. rosenbergii production is more economically and environmentally sustainable than other intensively reared crustacean species due to its use of low stocking densities [20].

Molecular tools are essential in aquaculture research, complementing traditional methods and enhancing insights into fish and shellfish responses to culture stress and environmental fluctuations [21–23]. Gene expression assays play a central role in understanding the molecular and physiological responses of aquatic organisms to salinity changes [24]. By analyzing the expression of genes related to growth, oxidative stress, and immunity, researchers can decipher how organisms maintain cellular homeostasis under varying salinity conditions [25].

The influence of salinity on the survival and growth has been reported for many economically significant penaeids [26–28]. Previous investigations demonstrated the effects of salinity gradients on physiological, biochemical and genetic markers in the prawn [4, 29, 30]. Osmoregulation, growth and molting cycles of M. rosenbergii in the Mekong river delta were found to be influenced by different salinity level [31]. Elevated salinity negatively affected the reproduction and growth of female M. Rosenbergii [32], and the highest growth rate was documented at 10 ppt salinity [33].

However, a few studies have investigated the effect of salinity on growth, and survival of M. rosenbergii, and changes in gene expression profiles at different salinities have not yet been studied. To address these issues, the present study was carried out to examine growth performance, feed utilization efficacy, survival, and mRNA expression of genes involved in growth, stress, and immune response at different salinities.

2. Materials and methods

2.1. Collection and acclimatization of experimental species

Juveniles of M. rosenbergii were procured from a commercial hatchery (Patuakhali, Bangladesh) and transported into an oxygenated polythene bag. The experiment was conducted at the facilities of the wet laboratory, Department of Aquaculture, Patuakhali Science and Technology University. Before the commencement of the experimental trial, M. rosenbergii were acclimatized under controlled laboratory condition for two weeks, and fed a commercial diet and live food up to the ad libitum.

2.2. Experimental layout

After the acclimatization period, active and healthy juveniles of M. rosenbergii were randomly allocated into five experimental categories. M. rosenbergii were equally distributed in 15 plastic tanks, and exposed to different salinity levels (0, 3, 6, 9, and 12 ppt) for 56 days (Fig 1). Three biological replications (20 juveniles/replication) for each experimental treatment were applied to conduct this study, and referred to as control, T1, T2, T3, and T4, respectively. Sufficient aeration was maintained using mechanical aerator and fed live food and commercial pelleted (35% crude protein, moisture 11%, lipid 6%, carbohydrate 22%, crude fiber 5%, ash 10%, calcium 2.5%, phosphorus 1.2%) feed twice a day up to the satiation level. Siphoning was done to remove the leftover food and fecal matters daily.

thumbnail
Download:
Fig 1. The experimental layout of salinity-induced changes in growth, feed utilization, and gene expression of M. rosenbergii.

https://doi.org/10.1371/journal.pone.0353240.g001

2.3. Growth performance, feed utilization, and survival

Following the experimental trial, M. rosenbergii were subjected to a one-day starvation period. Subsequently, the total length and final weight of M. rosenbergii were measured by using a slide calipers, and a digital balance, respectively. Growth parameters (weight gain, percentage weight gain, specific growth rate, survival), feed utilization parameters (feed conversion ratio, protein efficiency ratio), biometric indices (hepato-somatic index, meat ratio), and condition factor were calculated by using formula as reported by [34].

2.4. Profiling of gene expression

Expression of the following genes, assumed important to growth, stress and immune response in M. rosenbergii, was studied: CHH (crustacean hyperglycemic hormone), MSTN (myostatin), CHIT3 (Chitinase 3), MIH (molt-inhibiting hormone), HSP 60 (heat shock protein 60), HSP 90 (heat shock protein 90), Cu/Zn SOD (superoxide dismutase), CAT (Catalase); α2-M, (alpha-2-macroglobulin); NF-κB (nuclear factor kappa B) The primers used for gene expression analysis are listed in Table 1. Hepatopancreas tissue samples were selected from each replication for the analysis of gene expression due to its role in metabolism, detoxification, and immunity. qRT-PCR assayfor the different genes were done following the method by [35–38]. Briefly, total RNA was extracted using an RNeasy mini kit (Qiagen, Hilden, Germany), after which Invitrogen’s Superscript® III First-Strand synthesis kit (Carlsbad, CA, USA) was employed for cDNA synthesis following the kit´s manual. The β-actin gene was chosen as an internal control, and three biological replicates were used for the qRT-PCR assays. The relative gene expression was quantified using the 2−ΔΔct method based on the cycle threshold [39].

thumbnail
Download:
Table 1. Forward (F) and reverse (R) primers used for real-time quantitative RT-PCR.

https://doi.org/10.1371/journal.pone.0353240.t001

2.5. Statistical analysis

The data were analyzed using one-way ANOVA in GraphPad Prism 9. Duncan's multiple range tests was used to detect significant differences among different treated groups at a 95% confidence level. All values are presented as mean ± standard deviation, with significance set at P ≤ 0.05. Biometric indices, condition factor, and survival were analyzed and visualized using the open-source R environment (version 4.2.1). The optimal salinity level for WG (g) and SGR (%/day) in M. rosenbergii was estimated using second-order polynomial regression analysis. The identified break–point indicates the optimum salinity level for maximizing growth. All the data in different treatment groups are presented as mean ± SD.

3. Results

3.1. Water quality parameters

The physico-chemical attributes of tank water measured during the experimental period were presented in Table 2. Throughout the trial period, these parameters did not significantly change or affect the different salinity treatments.

thumbnail
Download:
Table 2. Analyzed water quality parameters following a 56-days growth trial of M. rosenbergii under different salinities. All calculated values are expressed as Mean±SD.

https://doi.org/10.1371/journal.pone.0353240.t002

3.2. Growth, and feed utilization attributes

The initial mean body weights of the M. rosenbergii were not significantly different (P > 0.05) at the beginning of the experimental trial. At the end of the 56-day experimental duration, the growth exhibited a significant increase in all examined growth metrices at 3 ppt as compared to the control and other treatments. Highest weight gain (WG), % WG, and specific growth rate (SGR) were recorded in prawns cultured in 3 ppt, followed by 0, 6, 9, and 12 ppt (Table 3). The quadratic regression analysis based on the WG (g) and SGR (%/day) demonstrated that the optimum salinity for the highest growth performance of M. rosenbergii was 3.12 for WG and 3.80 for SGR (Fig 2). The prawns reared at 3 ppt also demonstrated the best feed conversion ratio (FCR) compared to the other treatments. The lowest value of protein efficiency ratio (PER) was obtained in prawns cultured in 12 ppt (Table 3).

thumbnail
Download:
Table 3. Growth attributes for M. rosenbergii reared in different salinities over a 56-day period. All calculated values are expressed as Mean±SD.

https://doi.org/10.1371/journal.pone.0353240.t003

thumbnail
Download:
Fig 2. Second-order polynomial regression analysis of A.

WG (g), (B) SGR (%/day) in M. rosenbergii across different salinities over 56-days.

https://doi.org/10.1371/journal.pone.0353240.g002

3.3. Biological indices, condition factor, and survival

Biological indices, condition factor, and survival of M. rosenbergii under different salinity treatments are presented in Fig 3. The highest values of hepatosomatic index (HSI) and meat ratio were determined in the T1 (3ppt) treatment group. The maximum condition factor (CF) was found in the control group, however not significantly different from the T1 group. The survival was similar between the control, T1, and T2 groups (P > 0.05) but lower for the T3 and T4 groups (P < 0.05)

thumbnail
Download:
Fig 3. Assessment of biometric indices, condition factor, and survival rate of M. rosenbergii subjected to varying salinity regimes.

https://doi.org/10.1371/journal.pone.0353240.g003

3.4. Profiling of gene expression

The expression of genes involved in growth, stress response, antioxidant enzymes, and immunity were studied under different salinity treatments. The quantity of total RNA isolated from the hepatopancreas of the prawns is presented in Supplementary Table 1. In the control treatment, the total RNA level was about 750.2 ± 1.63 ng/µL. The prawns reared in 3ppt salinity exhibited a higher amount of total RNA (910.8 ± 2.13 ng/µL) than did other tested treatments.

3.5. Changes in expression of growth factor gene

The expression levels of MSTN and CHH transcript in M. rosenbergii are shown in Fig 4. The mRNA expression of these genes was influenced by the different salinity treatments. M. rosenbergii exposed to a rearing salinity of 3 ppt exhibited a significantly lower MSTN mRNA transcript level as compared to the control group. However, when the rearing salinity was further increased to 6 ppt, no significant differences in mRNA transcript levels were observed relative to the control. Significantly higher expression was found when rearing at 9 ppt and 12 ppt (Fig 4A). The transcript of CHH was significantly upregulated when rearing at 3 ppt. Although CHH mRNA expression showed a moderate increase at 6 ppt, the change was not statistically significant (Fig 4B). No significant difference in mRNA transcript levels was observed among exposures at 0, 9, and 12.

thumbnail
Download:
Fig 4. Changes in relative mRNA transcript of growth factor-related genes in hepatopancreas (A), MSTN (B), CHH of M. rosenbergii after exposure to different salinities.

https://doi.org/10.1371/journal.pone.0353240.g004

3.6. Changes in expression of molting-related gene

The expressions of molting-related genes (MIH and CHIT) were modulated under different salinity treatments in M. rosenbergii (Fig 5). At 3 ppt salinity, the MIH gene expression was down-regulated markedly, whereas the CHIT was up-regulated, as compared to the control (Fig 5A, 5B). The expression levels of the MIH and CHIT genes were elevated at 9 ppt but showed no significant difference compared to the control. Significantly higher expression of MIH and lower expression of CHIT was found in the 12 ppt salinity treatment group.

thumbnail
Download:
Fig 5. Changes in relative mRNA transcript of molting related gene in hepatopancreas of (A), MIH (B), CHIT of M. rosenbergii after exposure to different salinities.

https://doi.org/10.1371/journal.pone.0353240.g005

3.7. Changes in expression of stress response gene

mRNA transcripts of the stress response gene (HSP 60 and HSP 90) indicate a significant down-regulated expression in M. rosenbergii exposed to 3 ppt, as compared to the control group (Fig 6A, 6B). An increase in rearing salinity to 9 ppt and 12 ppt showed significantly higher HSP 60 mRNA transcript levels relative to the control. Although the expression level of HSP90 moderately increased at 9 ppt and 12 ppt rearing conditions, the differences were not statistically significant from the control group (Fig 6B).

thumbnail
Download:
Fig 6. Changes in relative mRNA transcript of antioxidant-related gene in hepatopancreas (A), HSP 70 (B), HSP 90 of M. rosenbergii after exposure to different salinities.

https://doi.org/10.1371/journal.pone.0353240.g006

3.8. Changes in expression of immune-related gene

The relative expression of immune-related genes (α2 macroglobulin and NF-κB) was significantly up-regulated in M. rosenbergii reared at 3 ppt salinity, as compared to the other groups (Fig 7A, 7B). The expression levels of α-2 macroglobulin and NF-κB genes were highest in prawns exposed to 3 ppt salinity, followed by the control group, 6 ppt, and 9 ppt, with the lowest expression observed in prawns from 12 ppt.

thumbnail
Download:
Fig 7. Changes in relative mRNA transcript of antioxidant-related gene in hepatopancreas (A), HSP 70 (B), HSP 90 of M. rosenbergii after exposure to different salinities.

https://doi.org/10.1371/journal.pone.0353240.g007

3.9. Changes in expression of antioxidant-related gene

Expression of the antioxidant related genes (Cu, Zn-SOD and CAT) showed that the genes involved in oxidative stress were up-regulated at 3 ppt salinity, while no significant differences were recorded for the other treatment groups (Fig 8A, 8B).

thumbnail
Download:
Fig 8. Changes in relative mRNA transcript of antioxidant related gene in hepatopancreas (A), Cu, Zn-SOD (B), CAT of M. rosenbergii after exposure to different salinities.

https://doi.org/10.1371/journal.pone.0353240.g008

4. Discussion

Salinity played a significant role in the rearing and survival rate of the giant freshwater prawn (M. rosenbergii). Among the water quality parameters, optimum salinity was found to be crucial for larval growth, nutrient utilization, and survival of the prawn [40]. Temperature also significantly influenced the growth and survival. Regarding other water quality parameters in the trials, both pH, dissolved oxygen, alkalinity, NH3, and NO2 remained within the optimal range for freshwater prawn culture throughout the experimental trial [33].

In this study, the maximum survival rate and growth performance were documented at a salinity level of 3 ppt, indicating favorable physiological conditions for this species at this salinity. In contrast to this, the lowest survival and growth rates were observed at 12 ppt, suggesting that elevated salinity levels may impose physiological stress, potentially affecting osmoregulation, metabolism and overall health. A previous study suggested that M. rosenbergii can be cultured in salinities up to 10 ppt, but a better production, larger individual size, and higher survival rates were observed at a salinity of 5 ppt [41]. In another study of salinity preferences, [32] observed that M. rosenbergii achieved its highest growth rate at 0 ppt salinity, but as the salinity increased, growth rates progressively declined and growth was inhibited at 18 ppt. A reduced growth at high salinity in prawns appears to be due to a decreased appetite and a reduced food assimilation efficiency [42,43].

At high salinities, studies have shown that hyper-osmoregulation in crustaceans requires energy, which is primarily derived from proteins and or lipids [43–45]. In addition to the physiological stress, the growth of M. rosenbergii can be adversely affected by elevated salinities due to increased energy expenditure, protein sparing, and depletion of lipid reserves. As a consequence, the biomass of M. rosenbergii is reduced relative to rearing in lower salinities [46]. Based on the results of the quadratic regression analysis, the optimal feeding rate should be determined by considering growth parameters, WG (g) and SGR (%/day). Our findings demonstrate that the optimal salinity levels for maximum growth performance and an efficient nutrient utilization are 3.12 ppt for WG and 3.80 ppt for SGR.

Condition factor (CF) is an important tool for evaluating shellfish health, providing insight into the overall well-being of a population by assessing its relative plumpness [47]. Here, we observed the highest CF value for rearing under the 3 ppt, but all CF values obtained in this study indicate that the experimental species were in good condition (Fig 3). The observed findings between WG and SGR, relative to FCR is in agreement with the findings of [48]Shi et al. (2024), who reported that FCR is significantly correlated with growth traits.

The application of molecular tools in recent aquaculture research has provided deeper insights into animal responses to culture-related stress and environmental fluctuations [21,22,49]. In this study, an attempt has been made to determine the mRNA expression of growth factors, stress responses, antioxidant enzymes, and immune-related genes under different salinity treatments.

Myostatin, belonging to the transforming growth factor (TGF)-β super family, suppresses the myoblasts differentiation and proliferation and is inversely associated with the growth traits of fish and shellfish [50]. MSTN negatively controls muscle growth by retarding protein synthesis and simultaneously promoting protein degradation, resulting in a decrease in skeletal muscle mass [51]. In our experiments, the expression of the MSTN gene in M. rosenbergii was down-regulated when reared under a salinity condition of 3 ppt. Thus, the low level of MSTN expression recorded in M. rosenbergii suggests a favorable growth, as it was inversely correlated with growth performance. Similar findings were earlier found for Litopenaeus. vannamei [52] and Fenneropenaeus chinensis [53], and also for M. rosenbergii [54]. Previous studies reported that crustacean hyperglycemic hormone CHH plays a role in multiple biological processes, including growth, molting, reproduction, metabolism, morphogenesis and osmoregulation [55,56]. In this study, CHH expression enhanced the growth performance of M. rosenbergii reared at 3 ppt salinity, suggesting that this salinity level stimulates metabolic activity. [57] reported that the expression pattern of CHH was markedly modulated in L. vannamei exposed to different salinity conditions

Molting is an important process in crustaceans during their entire growth and development. The molting is significantly influenced by molting inhibitory hormone (MIH) [58]. This enzyme plays a pivotal role by inhibiting the molting of crustaceans by lessening the formation of ecdysteroids [59] and other molting related compounds [60]. In our study, MIH gene expression in M. rosenbergii was significantly up-regulated at 12 ppt salinity, compared to the other salinities, indicating physiological stress or altered endocrine regulation, potentially leading to decrease molting activity. It has been reported that MIH inhibits the activity of Y-organs throughout the molting period [61] and that a lowered level of MIH secretion influences the molting in crustacean [62]. [63] have also reported that the mRNA transcript of the MIH gene in L. vannamei is significantly influenced by salinity fluctuations. A significantly lower expression of the CHIT gene at 12 ppt salinity indicating that excessive salinity may inhibit expression, potentially negatively affecting the molting and metamorphosis of M. rosenbergii. According to previous findings, different isoforms of CHIT showed significant up-regulation in the mud crab (Macrophthalmus japonicas) when exposed to different salinities [64]. Thus, chitinase production reflects molting in M. rosenbergii and other crustaceans.

HSPs are the prime stress proteins synthesized by organisms and serves as a biological response marker for stress indication [65]. HSPs play an influential role in both innate and adaptive immune activation and responses [66]. In this study, the expression levels of the HSP60 and HSP90 mRNA transcripts were markedly decreased at a salinity of 3 ppt, suggesting a role in maintaining cellular homeostasis. These findings were in accordance with [67], who reported that the expression of different isoforms of HSPs showed down-regulation in the M. japonicus after exposure of low salinity stress. In Portunus trituberculatus, exposure to low salinity conditions led to the down-regulation of heat shock protein (HSP) gene expression [68].

Antioxidant enzymes play an influential role in mitigating oxidative stress by neutralizing excessive reactive oxygen species (ROS) [69]. It is well-documented that the expression levels of both SOD (superoxide dismutase) and CAT (catalase) are key biomarkers for evaluating the antioxidative defense mechanisms against pathogenic infections in L. vannamei [70]. In this study, salinity exposure at 3 ppt in M. rosenbergii led to the up-regulation of antioxidant enzyme genes, indicating defensive response by scavenging free radicals.

Crustaceans possess a highly responsive innate immune system that relies on multiple immune -related proteins associated with the prophenoloxidase (proPO) system. Among these proteins, α2-macroglobulin plays a critical role in pathogen defense and immune regulation by inhibiting proteases that trigger the proPO activation [71,72]. The present results indicate a significant increase in α2-M mRNA expression at 3 ppt, suggesting its role in modulating the immune response. NF-κB (nuclear factor kappa B) is a highly conserved transcription factor that plays a crucial role in regulating the expression of downstream genes involved in various cellular processes. In M. rosenbergii NF-κB exhibited significantly higher expression levels in the 3ppt salinity group compared to the other groups, suggesting its involvement in stress adaptation and cellular response mechanisms. This was in agreement with the results in previous findings reported by [73]. The upregulation of SOD, CAT, α2-M, and NF-κB at 3 PPT does not indicate a detrimental stress. Rather, it reflects a mild adaptive response, in which low salinity acts as a physiological stimulus. This homeostatic effect enhances antioxidant and immune functions while maintaining optimal growth and survival, indicating a balanced distribution of energy between growth and defense. Furthermore, at higher salinities (9 and 12 ppt), the upregulation of stress-responsive genes and downregulation of immune-related genes may reflect increased osmoregulatory and physiological stress. These changes could be associated with reduced energy allocation to immune function, thereby contributing to growth inhibition and decreased survival rates.

5. Conclusions

Salinity gradient has been inconsistent gradually affecting growth, reproduction, and other physiological traits in fish and invertebrates. The findings of the present investigation recommended that 3 ppt salinity is optimum for substantial growth, feed utilization, and other physico-biochemical profiles in M. rosenbergii. However, exploration of the effects of salinity gradient on enzymatic and non-enzymatic antioxidant assay, and transcriptomic analysis is a warrant for future studies.

Supporting information

S1 Table. Concentration, and purity of RNA isolated from the hepatopancreas of M. rosenbergii (n = 3) under different salinity treatment.

https://doi.org/10.1371/journal.pone.0353240.s001

(DOCX)

References

  1. 1. Velasco J, Gutiérrez-Cánovas C, Botella-Cruz M, Sánchez-Fernández D, Arribas P, Carbonell JA, et al. Effects of salinity changes on aquatic organisms in a multiple stressor context. Philos Trans R Soc Lond B Biol Sci. 2018;374(1764):20180011. pmid:30509913
  2. 2. Kujawa R, Piech P. Influence of Water Salinity on the Growth and Survivability of Asp Larvae Leuciscus aspius (Linnaeus, 1758) under Controlled Conditions. Animals (Basel). 2022;12(17):2299. pmid:36078019
  3. 3. Kumlu M, Eroldogan OT, Saglamtimur B. The effects of salinity and added substrates on growth and survival of Metapenaeus monoceros (Decapoda: Penaeidae) post-larvae. Aquaculture. 2001;196(1–2):177–88.
  4. 4. Ye L, Jiang S, Zhu X, Yang Q, Wen W, Wu K. Effects of salinity on growth and energy budget of juvenile Penaeus monodon. Aquaculture. 2009;290(1–2):140–4.
  5. 5. Romano N, Zeng C. The effects of salinity on the survival, growth and haemolymph osmolality of early juvenile blue swimmer crabs, Portunus pelagicus. Aquaculture. 2006;260(1–4):151–62.
  6. 6. Badjeck M-C, Allison EH, Halls AS, Dulvy NK. Impacts of climate variability and change on fishery-based livelihoods. Marine Policy. 2010;34(3):375–83.
  7. 7. Schlaff AM, Heupel MR, Simpfendorfer CA. Influence of environmental factors on shark and ray movement, behaviour and habitat use: a review. Rev Fish Biol Fisheries. 2014;24(4):1089–103.
  8. 8. Moniruzzaman M, Mukherjee M, Kumar S, Chakraborty SB. Effects of salinity stress on antioxidant status and inflammatory responses in females of a “Near Threatened” economically important fish species Notopterus chitala: a mechanistic approach. Environ Sci Pollut Res Int. 2022;29(49):75031–42. pmid:35650341
  9. 9. Pan YJ, Souissi A, Souissi S, Hwang JS. Effects of salinity on the reproductive performance of Apocyclops royi (Copepoda, Cyclopoida). J Exp Mar Bio Ecol. 2016;475:108–13.
  10. 10. Hossain F, Islam SMM, Ashaf-Ud-Doulah M, Ali MS, Islam MS, Brown C. Influences of salinity on embryonic and larval development of striped catfish Pangasianodon hypophthalmus. Frontiers in Marine Science. 2021;8:781951.
  11. 11. Alam MZ, Carpenter-Boggs L, Mitra S, Haque MM, Halsey J, Rokonuzzaman M. Effect of salinity intrusion on food crops, livestock, and fish species at Kalapara coastal belt in Bangladesh. J Food Qual. 2017;2017:2045157.
  12. 12. Hieu DQ, Hang BTB, Lokesh J, Garigliany M-M, Huong DTT, Yen DT, et al. Salinity significantly affects intestinal microbiota and gene expression in striped catfish juveniles. Appl Microbiol Biotechnol. 2022;106(8):3245–64. pmid:35366085
  13. 13. Morash AJ, Alter K. Effects of environmental and farm stress on abalone physiology: perspectives for abalone aquaculture in the face of global climate change. Rev Aquac. 2016;8:342–68.
  14. 14. Nguyen AL, Dang VH, Bosma RH, Verreth JAJ, Leemans R, De Silva SS. Simulated impacts of climate change on current farming locations of striped catfish (Pangasianodon hypophthalmus; Sauvage) in the Mekong Delta, Vietnam. Ambio. 2014;43(8):1059–68. pmid:24715387
  15. 15. Ashrafuzzaman M, Artemi C, Santos FD, Schmidt L. Current and Future Salinity Intrusion in the South-Western Coastal Region of Bangladesh. Span J Soil Sci. 2022;12.
  16. 16. Saoud IP, Davis DA, Rouse DB. Suitability studies of inland well waters for Litopenaeus vannamei culture. Aquaculture. 2003;217(1–4):373–83.
  17. 17. Shakeeb-Ur-Rahman, Jain AK, Reddy AK, Kumar G, Raju KD. Ionic manipulation of inland saline groundwater for enhancing survival and growth of Penaeus monodon (Fabricius). Aquac Res. 2005;36:1149–56.
  18. 18. New MB. Freshwater prawn farming: global status, recent research and a glance at the future. Aquac Research. 2005;36(3):210–30.
  19. 19. Muralisankar T, Bhavan PS, Radhakrishnan S, Seenivasan C, Manickam N, Shanthi R. Effects of dietary supplementation of fish and vegetable oils on the growth performance and muscle compositions of the freshwater prawn Macrobrachium rosenbergii. The Journal of Basic & Applied Zoology. 2014;67(2):34–9.
  20. 20. Paulraj A, Devi K, Kathiravan, Mohamed MJ, Musthafa MS, Peixoto S, et al. Role of mesophilic fungal biomass and diversity in the pond soil for the productivity of freshwater prawn Macrobrachium rosenbergii. Aquaculture. 2021;545:737250.
  21. 21. Stone DAJ, Gaylord TG, Johansen KA, Overturf K, Sealey WM, Hardy RW. Evaluation of the effects of repeated fecal collection by manual stripping on the plasma cortisol levels, TNF-α gene expression, and digestibility and availability of nutrients from hydrolyzed poultry and egg meal by rainbow trout, Oncorhynchus mykiss (Walbaum). Aquaculture. 2008;275(1–4):250–9.
  22. 22. Panserat S, Kaushik SJ. Regulation of gene expression by nutritional factors in fish. Aquacult Res. 2010;41:751–62.
  23. 23. Petitjean Q, Jean S, Gandar A, Côte J, Laffaille P, Jacquin L. Stress responses in fish: From molecular to evolutionary processes. Sci Total Environ. 2019;684:371–80. pmid:31154210
  24. 24. Hu W, Cao Y, Liu Q, Yuan C, Hu Z. Effect of salinity on the physiological response and transcriptome of spotted seabass (Lateolabrax maculatus). Mar Pollut Bull. 2024;203:116432. pmid:38728954
  25. 25. Ahmed H, Bakry KA, Abdeen A, El bahgy HEK, Abdo M, Imbrea F. The involvement of antioxidant, stress, and immune-related genes in the responsive mechanisms of common carp (Cyprinus carpio) to hypersalinity exposure. Frontiers in Marine Science. 2023;10:1195016.
  26. 26. Huang M, Dong Y, Zhang Y, Chen Q, Xie J, Xu C, et al. Growth and Lipidomic Responses of Juvenile Pacific White Shrimp Litopenaeus vannamei to Low Salinity. Front Physiol. 2019;10:1087. pmid:31507450
  27. 27. Laramore S, Laramore CR, Scarpa J. Effect of Low Salinity on Growth and Survival of Postlarvae and Juvenile Litopenaeus vannamei. J World Aquaculture Soc. 2001;32(4):385–92.
  28. 28. Gao W, Tian L, Huang T, Yao M, Hu W, Xu Q. Effect of salinity on the growth performance, osmolarity and metabolism-related gene expression in white shrimp Litopenaeus vannamei. Aquaculture Reports. 2016;4:125–9.
  29. 29. Rahi MdL, Sabbir W, Salin KR, Aziz D, Hurwood DA. Physiological, biochemical and genetic responses of black tiger shrimp (Penaeus monodon) to differential exposure to white spot syndrome virus and Vibrio parahaemolyticus. Aquaculture. 2022;546:737337.
  30. 30. Rahi ML, Azad KN, Tabassum M, Irin HH, Hossain KS, Aziz D, et al. Effects of Salinity on Physiological, Biochemical and Gene Expression Parameters of Black Tiger Shrimp (Penaeus monodon): Potential for Farming in Low-Salinity Environments. Biology (Basel). 2021;10(12):1220. pmid:34943135
  31. 31. Huong DTT, Wang T, Bayley M, Phuong NT. Osmoregulation, growth and moulting cycles of the giant freshwater prawn (Macrobrachium rosenbergii) at different salinities. Aquac Res. 2010;41:e135–43.
  32. 32. Yen PT, Bart AN. Salinity effects on reproduction of giant freshwater prawn Macrobrachium rosenbergii (de Man). Aquaculture. 2008;280(1–4):124–8.
  33. 33. Chand BK, Trivedi RK, Dubey SK, Rout SK, Beg MM, Das UK. Effect of salinity on survival and growth of giant freshwater prawn Macrobrachium rosenbergii (de Man). Aquaculture Reports. 2015;2:26–33.
  34. 34. Sharker MdR, Azim A, Siddik MAB, Choi SD, Halder P, Haque MdN, et al. Nutritional and functional benefits of Gracilaria tenuistipitata in aquafeed: Impacts on growth, hemato-biochemical profile, and economic efficiency in Nile tilapia culture. Aquaculture Reports. 2025;42:102734.
  35. 35. Sharker MR, Kim SC, Hossen S, Sumi KR, Choi SK, Choi KS. Carbonic Anhydrase in Pacific Abalone Haliotis discus hannai: Characterization, Expression, and Role in Biomineralization. Front Mol Biosci. 2021;8.
  36. 36. Sharker MR, Sukhan ZP, Sumi KR, Choi SK, Choi KS, Kho KH. Molecular characterization of carbonic anhydrase II (CA II) and its potential involvement in regulating shell formation in the Pacific abalone, Haliotis discus hannai. Front Mol Biosci. 2021;8:669235.
  37. 37. Sharker MdR, Hasan KR, Alam MdA, Haque MN, Choi SD, Islam MF, et al. Effects of moringa (Moringa oleifera) leaf powder supplementation on growth performance, haematobiochemical parameters and gene expression profile of stinging catfish, Heteropneustes fossilis. Aquaculture Reports. 2024;39:102388.
  38. 38. Sharker MR, Sumi KR, Afroz M, Haque SA, Islam MF, Rahman MM, et al. Effects of dietary Mango Kernel Meal (MKM) inclusion on growth indices, haemato-biochemical profiles, and growth and immune-regulatory genes of Gibelion catla. Sci Rep. 2025;15(1):23789. pmid:40610546
  39. 39. Livak KJ, Schmittgen TD. Analysis of relative gene expression data using real-time quantitative PCR and the 2(-Delta Delta C(T)) Method. Methods. 2001;25(4):402–8. pmid:11846609
  40. 40. Hosain MdE, Amin SMN, Kamarudin MS, Arshad A, Karim M, Romano N. Effect of salinity on growth, survival, and proximate composition of Macrobrachium rosenbergii post larvae as well as zooplankton composition reared in a maize starch based biofloc system. Aquaculture. 2021;533:736235.
  41. 41. Nair CM, Salin KR. Current status and prospects of farming the giant river prawn Macrobrachium rosenbergii (De Man) and the monsoon river prawn Macrobrachium malcolmsonii (H.M. Edwards) in India. Aquac Res. 2012;43:999–1014.
  42. 42. Lemos D, Phan VN, Alvarez G. Growth, oxygen consumption, ammonia-N excretion, biochemical composition and energy content of Farfantepenaeus paulensis Pérez-Farfante (Crustacea, Decapoda, Penaeidae) early postlarvae in different salinities. J Exp Mar Biol Ecol. 2001;261(1):55–74. pmid:11438105
  43. 43. Minh Sang H, Fotedar R. Growth, survival, haemolymph osmolality and organosomatic indices of the western king prawn (Penaeus latisulcatus Kishinouye, 1896) reared at different salinities. Aquaculture. 2004;234(1–4):601–14.
  44. 44. Silvia G-J, Abel Antonio U-R, Francisco V-O, Georgina H-W. Ammonia efflux rates and free amino acid levels in Litopenaeus vannamei postlarvae during sudden salinity changes. Aquaculture. 2004;233(1–4):573–81.
  45. 45. Setiarto A, Strüssmann CA, Takashima F, Watanabe S, Yokota M. Short-term responses of adult kuruma shrimp Marsupenaeus japonicus (Bate) to environmental salinity: osmotic regulation, oxygen consumption and ammonia excretion. Aquac Res. 2004;35:669–77.
  46. 46. Li X, Xu B, Shen P, Cheng H, Fan Y, Gao Q. Regulation and Response Mechanism of Acute Low-Salinity Stress during Larval Stages in Macrobrachium rosenbergii Based on Multi-Omics Analysis. Int J Mol Sci. 2024;25(12):6809. pmid:38928514
  47. 47. de Carvalho-Souza GF, Medeiros DV, Silva R de A, González-Ortegón E. Width/length–weight relationships and condition factor of seven decapod crustaceans in a Brazilian tropical estuary. Reg Stud Mar Sci. 2023;60:102880.
  48. 48. Shi X, Yuan S, Ma X, Tian X, Zhang M, Zhang Y, et al. Analysis of relationship between growth traits and feed conversion ratio provides insights into aquaculture and breeding of largemouth bass Micropterus salmoides. Aquaculture. 2024;593:741352.
  49. 49. Liu Y, Yao M, Li S, Wei X, Ding L, Han S, et al. Integrated application of multi-omics approach and biochemical assays provides insights into physiological responses to saline-alkaline stress in the gills of crucian carp (Carassius auratus). Sci Total Environ. 2022;822:153622. pmid:35124035
  50. 50. Abdel-Aziem SH, Mahrous KF, Abd El-Hafez MAM, Abdel Mordy M. Genetic variability of myostatin and prolactin genes in popular goat breeds in Egypt. J Genet Eng Biotechnol. 2018;16(1):89–97. pmid:30647710
  51. 51. Segev-Hadar A, Alupo G, Tal K, Nitzan T, Biran J. Identification and Characterization of a Non-muscular Myostatin in the Nile Tilapia. Front Endocrinol (Lausanne). 2020;11:94. pmid:32180761
  52. 52. Qian Z, Mi X, Wang X, He S, Liu Y, Hou F, et al. cDNA cloning and expression analysis of myostatin/GDF11 in shrimp, Litopenaeus vannamei. Comp Biochem Physiol A Mol Integr Physiol. 2013;165(1):30–9. pmid:23402749
  53. 53. Yan Y, Lu X, Kong J, Meng X, Luan S, Dai P, et al. Molecular characterization of myostatin and its inhibitory function on myogenesis and muscle growth in Chinese Shrimp, Fenneropenaeus chinensis. Gene. 2020;758:144986. pmid:32711100
  54. 54. Satgurunathan T, Bhavan PS, Kalpana R, Jayakumar T, Sheu J-R, Manjunath M. Influence of Garlic (Allium sativum) Clove-Based Selenium Nanoparticles on Status of Nutritional, Biochemical, Enzymological, and Gene Expressions in the Freshwater Prawn Macrobrachium rosenbergii (De Man, 1879). Biol Trace Elem Res. 2023;201(4):2036–57. pmid:35665883
  55. 55. Xu Y, Peng G, Sun M, Li J, Yan W, Tang J, et al. Genomic organization of the molt-inhibiting hormone gene in the red swamp crayfish Procambarus clarkii and characterization of single-nucleotide polymorphisms associated with growth. Comp Biochem Physiol B Biochem Mol Biol. 2019;237:110334. pmid:31472239
  56. 56. Qiao H, Jiang F, Xiong Y, Jiang S, Fu H, Li F, et al. Characterization, expression patterns of molt-inhibiting hormone gene of Macrobrachium nipponense and its roles in molting and growth. PLoS One. 2018;13(6):e0198861. pmid:29889902
  57. 57. Camacho-Jiménez L, Díaz F, Sánchez-Castrejón E, Ponce-Rivas E. Effects of the recombinant crustacean hyperglycemic hormones rCHH-B1 and rCHH-B2 on the osmo-ionic regulation of the shrimp Litopenaeus vannamei exposed to acute salinity stress. J Comp Physiol B. 2018;188(4):565–79. pmid:29582134
  58. 58. Chung JS, Webster SG. Moult cycle-related changes in biological activity of moult-inhibiting hormone (MIH) and crustacean hyperglycaemic hormone (CHH) in the crab, Carcinus maenas. From target to transcript. Eur J Biochem. 2003;270(15):3280–8. pmid:12869204
  59. 59. Mykles DL. Ecdysteroid metabolism in crustaceans. J Steroid Biochem Mol Biol. 2011;127(3–5):196–203. pmid:20837145
  60. 60. Hopkins PM. The eyes have it: A brief history of crustacean neuroendocrinology. Gen Comp Endocrinol. 2012;175(3):357–66. pmid:22197211
  61. 61. Nakatsuji T, Sonobe H. Regulation of ecdysteroid secretion from the Y-organ by molt-inhibiting hormone in the American crayfish, Procambarus clarkii. Gen Comp Endocrinol. 2004;135(3):358–64. pmid:14723887
  62. 62. Nakatsuji T, Lee C-Y, Watson RD. Crustacean molt-inhibiting hormone: structure, function, and cellular mode of action. Comp Biochem Physiol A Mol Integr Physiol. 2009;152(2):139–48. pmid:19000932
  63. 63. Zhang D, Guo X, Wang F, Dong S. Effects of periodical salinity fluctuation on the growth, molting, energy homeostasis and molting-related gene expression of Litopenaeus vannamei. J Ocean Univ China. 2016;15(5):911–7.
  64. 64. Nikapitiya C, Kim W-S, Park K, Kim J, Lee M-O, Kwak I-S. Chitinase gene responses and tissue sensitivity in an intertidal mud crab (Macrophthalmus japonicus) following low or high salinity stress. Cell Stress Chaperones. 2015;20(3):517–26. pmid:25697403
  65. 65. Hu C, Yang J, Qi Z, Wu H, Wang B, Zou F, et al. Heat shock proteins: Biological functions, pathological roles, and therapeutic opportunities. MedComm (2020). 2022;3(3):e161. pmid:35928554
  66. 66. Roberts RJ, Agius C, Saliba C, Bossier P, Sung YY. Heat shock proteins (chaperones) in fish and shellfish and their potential role in relation to fish health: a review. J Fish Dis. 2010;33(10):789–801. pmid:20678104
  67. 67. Park K, Kwak I-S. Salinity and bisphenol A alter cellular homeostasis and immune defense by heat shock proteins in the intertidal crab Macrophthalmus japonicus. Estuarine, Coastal and Shelf Science. 2019;229:106381.
  68. 68. Bao XN, Mu CK, Zhang C, Wang YF, Song WW, Li RH, et al. mRNA expression profiles of heat shock proteins of wild and salinity-tolerant swimming crabs, Portunus trituberculatus, subjected to low salinity stress. Genet Mol Res. 2014;13(3):6837–47. pmid:25177963
  69. 69. Guo H, Miao Y-T, Xian J-A, Qian K, Wang A-L. Expression Profile of Antioxidant Enzymes in Hemocytes from Freshwater Prawn Macrobrachium rosenbergii Exposed to an Elevated Level of Copper. Bull Environ Contam Toxicol. 2015;95(4):447–51. pmid:26215459
  70. 70. Campa-Córdova AI, Hernández-Saavedra NY, De Philippis R, Ascencio F. Generation of superoxide anion and SOD activity in haemocytes and muscle of American white shrimp (Litopenaeus vannamei) as a response to beta-glucan and sulphated polysaccharide. Fish Shellfish Immunol. 2002;12(4):353–66. pmid:12049170
  71. 71. Zarantoniello M, Chemello G, Ratti S, Pulido-Rodríguez LF, Daniso E, Freddi L, et al. Growth and Welfare Status of Giant Freshwater Prawn (Macrobrachium rosenbergii) Post-Larvae Reared in Aquaponic Systems and Fed Diets including Enriched Black Soldier Fly (Hermetia illucens) Prepupae Meal. Animals (Basel). 2023;13(4):715. pmid:36830501
  72. 72. Lee SY, Söderhäll K. Early events in crustacean innate immunity. Fish Shellfish Immunol. 2002;12(5):421–37. pmid:12194453
  73. 73. Chui APY, Wong YH, Sun J, Chang TKT, Qiu JW, Qian PY. Effects of heat and hyposalinity on the gene expression in Acropora pruinosa larvae. Frontiers in Marine Science. 2023;10:1096407.
  74. 74. Thanh NM, Barnes AC, Mather PB, Li Y, Lyons RE. Single nucleotide polymorphisms in the actin and crustacean hyperglycemic hormone genes and their correlation with individual growth performance in giant freshwater prawn Macrobrachium rosenbergii. Aquaculture. 2010;301(1–4):7–15.
  75. 75. P. E. S, Bhassu S, Maningas MBB, Othman RY. Myostatin: A Potential Growth‐Regulating Gene in Giant River Prawn, Macrobrachium rosenbergii. J World Aquaculture Soc. 2015;46(6):624–34.
  76. 76. Xu J, Peng X, Li F, Zhang S, Wang T, Dong X, et al. Effects of astaxanthin in diet on antioxidant capacity and molting-related genes expression of larvae giant freshwater prawn (Macrobrachium rosenbergii). Aquaculture Reports. 2024;35:101956.
  77. 77. Gao X, Zhou Y, Zhu X, Tang H, Li X, Jiang Q, et al. Enterobacter cloacae: A probable etiological agent associated with slow growth in the giant freshwater prawn Macrobrachium rosenbergii. Aquaculture. 2021;530:735826.
  78. 78. Tadese DA, Tesfaye G, Tamiru M, Takele L, Geda F. Effect of emodin on growth performance, antioxidant status, intestinal morphology and heat shock protein gene expressions of freshwater prawn (Macrobrachium rosenbergii). J Fish. 2022;10:103205–103205.
  79. 79. Ding Z, Zhang Y, Ye J, Du Z, Kong Y. An evaluation of replacing fish meal with fermented soybean meal in the diet of Macrobrachium nipponense: Growth, nonspecific immunity, and resistance to Aeromonas hydrophila. Fish Shellfish Immunol. 2015;44(1):295–301. pmid:25707598
  80. 80. Dong X, Liu Q, Zhao W, Ou J, Jiang FJ, Guo H, et al. Italian Journal of Animal Science. 2021;20:453–64.
  81. 81. Feng P, He J, Lv M, Huang G, Chen X, Yang Q, et al. Effect of dietary Tenebrio molitor protein on growth performance and immunological parameters in Macrobrachium rosenbergii. Aquaculture. 2019;511:734247.
  82. 82. Zhan F, Zhou S, Shi F, Li Q, Lin L, Qin Z. Transcriptome analysis of Macrobrachium rosenbergii hemocytes in response to Staphylococcus aureus infection. Fish Shellfish Immunol. 2023;139:108927. pmid:37406892