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Aim: To assess the impact of different carbon sources on growth performance of grey mullet, Mugil cephalus fry in biofloc based culture system during nursery rearing phase. Methodology: The experimental trial was carried out for 60 days using three carbon sources, cassava, jaggery and barley in triplicate following a Completely Randomized Design. The carbon nitrogen ratio (C:N) in the systems were maintained at 15:1. Grey mullet fry (0.91g) were stocked @ of 1 fry 10 l-1 and were fed with pelleted feed (35% crude protein) @ 4% of fish body weight thrice daily. Results: Significantly higher (P

Aim: This study aimed to investigate the effectiveness of ethanolic extract of three Himalayan plants Myrica esculenta, Thymus linearis and Butea monosperma on hyphal germination, colonisation and sporulation of two species of Saprolegnia (Saprolegnia parasitica and S. australis) isolated from rainbow trout, Oncorhynchus mykiss. Molecular docking of active ingredients of M. esculenta, Myricetin with effector proteins of S. parasitica was also performed to investigate the target binding sites for drug development. Methodology: Minimum inhibitory concentration (MIC), mycelium growth inhibition, spore germination, and inhibition was performed with the most effective concentrations. Molecular docking was carried out with AutoDock Vina software to investigate target binding sites with S. parasitica. Results: Extracts from Myrica esculenta, Thymus linearis and Butea monosperma showed MIC values of the 25, 100, 50 mg ml-1 against S. parasitica and 25, 50, 25 mg ml-1 against S. australis hyphal growth, respectively. Nevertheless, malachite green as reference control was effective with a MIC value of 2.5 mg l-1. The concentration required to inhibit S. parasitica and S. australis spores were (50) Myrica esculenta, (25) Thymus linearis, (100) Butea monosperma in mg ml-1 and (50) Myrica esculenta, (50) Thymus linearis, (100) Butea monosperma in mg ml-1, respectively. Interpretation: The study concludes that M. esculenta and B. monosperma are effective against Saprolegniasis and could be used as phyto additives.

Global agriculture is facing tremendous challenges due to climate change. The most predominant amongst these challenges are abiotic and biotic stresses caused by increased incidences of temperature extremes, drought, unseasonal flooding, and pathogens. These threats, mostly due to anthropogenic activities, resulted in severe challenges to crop and livestock production leading to substantial economic losses. It is essential to develop environmentally viable and cost-effective green processes to alleviate these stresses in the crops, livestock, and fisheries. The application of nanomaterials in farming practice to minimize nutrient losses, pest management, and enhance stress resistance capacity is of supreme importance. This paper explores innovative methods for synthesizing nanostructured materials using plants, animals, and fisheries wastes and their valorization to mitigate abiotic and biotic stresses and input use efficiency in climate-smart, and stress-resilient agriculture including crop plants, livestock, and fisheries.

Aim: The objective of the study was to assess the effect of supplementation with dietary shatavari, Asparagous racemosus root extract on growth, feed conversion and nutrient utilization in Labeo rajasthanicus. Methodology: Two-hundred-seventy fingerlings of equal size (8.19±0.03g) were stocked in 18 fibre reinforced plastic tanks following complete randomized design. Six iso-nitrogenous (30% crude protein) and iso-caloric (390 kcal digestible energy per 100 g) diets were prepared with graded level of ethanolic shatavari root extract, i.e., 0.00, 0.15, 0.30, 0.45, 0.60, 0.75 g kg-1 and designated as control, T1, T2, T3, T4 and T5 were fed to L. rajasthanicus twice a day for 45 days. The growth performance, feed conversion and nutrient utilisation were considered as response parameters. Results: Significantly (P

The success of any aquaculture endeavour broadly depends on water quality. Water quality determines to a great extent the success or failure of aquaculture operation. Optimum water quality is considered necessary for any aquaculture operation as it influences the productivity of production system. In the present review, the role of major abiotic factors such as water pH and hardness on the biological processes of fish like growth, survival, reproductive performance and embryology has been discussed.

Background: Stunting is a process of suppressing growth from unfavourable conditions. The protein supplementation during stunting gives scope to maintain the nutrient reserves of fish and its quality. Methods: A feeding trial was conducted for eight months to study the effect of three hetero-nitrogenous diets with 25% (control), 30% (T1) and 35% (T2) crude protein (CP) levels on growth and physio-metabolic responses of Chanos chanos fingerlings during stunting. Milk fish fingerlings with a mean body weight of 11.71±0.18 g were stocked in earthen ponds @ 20 no/m2 in each replicate (n=3) was fed @ 2% biomass throughout the experiment. Result: Fish fed with T1 diet showed better specific growth rate (0.64±0.01% d-1), weight gain percentage (362.56±14.95) and protease activity (7.53±0.25 U/mg protein). Whereas, lower activity was observed for the enzyme assay, namely superoxide dismutase (45.41±2.50 U/min/mg protein), aspartate aminotransferase (34.01±1.88 U/min/mg protein) and alanine aminotransferase (39.64±0.64 U/min/mg protein). Hence, it may be concluded that the dietary protein inclusion level of 30% CP showed better growth performance and lower physio-metabolic response in milkfish fingerlings during the stunting.

The present study was conducted for 240 days to evaluate the effects of stocking density based on growth attributes, digestive enzymes, muscular composition, biochemical and physiological responses of Labeo rohita fingerlings in tropical inland open water cages. L. rohita (30.35±1.08 g) were randomly distributed into three treatments, namely low stocking density, LSD (10 m− 3), medium stocking density, MSD (20 m− 3) and high stocking density, HSD (30 m− 3) in triplicates. Fish were fed twice daily with CIFRI CAGEGROW® floating feed (crude protein-28%, crude fat-4%). Fish growth and feed efficiency was higher (P+, Cl− and K+) observed under crowding stress. Based on growth attributes and multiple biomarker responses, L. rohita @ 10 m− 3 found to be optimum density for inland open water cage culture.

The present study was conducted for 240 days to evaluate the effects of stocking density based on growth attributes, digestive enzymes, muscular composition, biochemical and physiological responses of Labeo rohita fingerlings in tropical inland open water cages. L. rohita (30.35 ± 1.08 g) were randomly distributed into three treatments, namely low stocking density, LSD (10 m−3), medium stocking density, MSD (20 m−3) and high stocking density, HSD (30 m−3) in triplicates. Fish were fed twice daily with CIFRI CAGEGROW® floating feed (crude protein-28%, crude fat-4%). Fish growth and feed efficiency were higher (p +, Cl− and K+) was observed under crowding stress. Based on growth attributes and multiple biomarker responses, L. rohita @ 10 m−3 was found to be the optimum density for inland open water cage culture.

An 18-months field trial was performed to explore the effect of duration of stunting on growth, digestive enzymes and carcass quality in Chanos chanos. Milkfish fry (weight of 1.25 ± 0.03 g and length of 5.53 ± 0.03 cm) were stocked in earthen ponds of 0.02 ha, in triplicate, for different duration of stunting, viz., 4 months (Treatment-1; T4), 8 months (Treatment-2; T8) and 12 months (Treatment-3; T12) and a normal seed (Control; C) separately. In the stunting phase, fish were stocked at higher stocking density (0.2 million/ha) and fed de-oiled rice bran at sub-optimal level. Post-stunting or re-feeding phase commenced immediately after completion of respective stunting duration and fish were reared for the rest of the period to complete the total rearing period of 18 months. In post-stunting, fish stocking density was adjusted to (5000 pieces/ha) and fed at an optimum level (3%). At the end of stunting phase, the study found a significant reduction in growth, survival, digestive enzymes activity, except protease in the T4 group, and carcass nutrients composition of stunted fish. However, in the initial phase of post-stunting, T8 group exhibited an elevated specific growth rate (5.00 ± 0.092%/day), body weight gain (80.82 ± 1.28 g), amylase (0.585 ± 0.021 U/mg protein), protease (5.48 ± 0.13 U/mg protein), and lipase activity (7.92 ± 0.32 U/mg protein). All stunted fish groups displayed a compensatory growth response in post-stunting, but a complete growth compensation was observed in T8 group, which resulted in better feed conversion ratio (3.03 ± 0.04) feed efficiency ratio (0.33 ± 0.01), protein efficiency ratio (1.91 ± 0.03), survival (91.38 ± 0.07%) and digestive enzyme activities. Similarly, at the end of post-stunting, carcass analysis revealed a complete restoration of nutrients in stunted fish and significantly higher protein content in T8 group. Further, the study found lower meat and higher bone contents in normally reared fish than the post-stunted fish which revealed the carcass quality improvement in post-stunted fish thus indicates superiority of the stunting process over normal rearing. Overall, the study suggests that stunting of milkfish, for 8 months (T8), positively affects its growth, survival, digestive enzyme activities and carcass quality which in turn, shall help to overcome the contemporary challenges in milkfish culture.

This study investigated the effect of dietary supplemented synthetic, and shrimp shell meal (SSM) derived natural astaxanthin combination on growth, digestive and metabolic enzyme activities, antioxidative status, physio-metabolic responses, and skin colouration of high valued discus (Symphysodon aequifasciatus) advanced juveniles reared in captive condition. Four isonitrogenous (50 % crude protein), isolipidic (9% ether extract), and isocaloric (around 400 kcal digestible energy/100 g) experimental diets viz. Control (only synthetic astaxanthin, without SSM), T1 (15 % SSM + synthetic astaxanthin), T2 (20 % SSM + synthetic astaxanthin), T3 (25 % SSM + synthetic astaxanthin) were prepared and fed to satiation level twice daily for 90 days. Results indicated significantly (P

An experiment of 36 days duration was conducted to study growth performance of goldfish Carassius auratus and basil Ocimum basilicum reared in a media bed aquaponic system. Goldfish fry (3.32 ± 0.45 g and 4.20 ± 0.39 cm) were stocked in rectangular 75 l capacity (water volume of 50 l) plastic tanks at three different stocking densities viz., 500 m-3 (T1), 600 m-3 (T2) and 700 m-3 (T3), respectively and basil plants were planted at a density of 20 m-2, i.e., 10 plants 0.44 m-2 in the rectangular plastic tanks filled with crushed stone media. The goldfish fry were fed with artificial feed (33% protein) at 5% of body weight in equal proportions, two times a day. Control (C) group was set with only basil plants. Growth parameters of goldfish such as length gain (%), weight gain (%) and specific growth rate (% d-1) were significantly higher in T3 (p

A 60-day feeding trial was performed to test the nutritional value and utilization possibility of palm kernel meal (PKM) as a feed ingredient for juvenile Labeo rohita. Five iso-nitrogenous diets were prepared with various inclusions of PKM which replaced sunflower oil cake and de-oiled rice bran namely, control (without PKM), T1 (50 g/kg PKM), T2 (100 g/kg PKM), T3 (150 g/kg PKM) and T4 (200 g/kg PKM). The experiment was conducted in 350 L fibre reinforced plastic tanks in triplicate and each tank stocked with twenty-five juvenile rohu (7.2 ± 0.01 g) were fed twice daily at 5% of body weight with the experimental diet. The growth performance values showed a higher overall linear trend in T2 and it is significantly different from control as well as T1 groups. Final results showed highest average body weight, specific growth rate, protein efficiency ratio, and apparent net protein utilization in a dose-dependent manner (p < 0.05). Significantly higher amylase, protease, and lipase activities were recorded in T2 treatment (p = 0.003, p = 0.001 and p = 0.002, respectively). Additionally, dietary PKM significantly lowered the aspartate amino transferase, alkaline amino transferase and alkaline phosphatase enzyme activities in a dose-dependent manner (p < 0.05). Significantly higher lactate dehydrogenase, malate dehydrogenase, superoxide dismutase and catalase activities in the liver tissues were recorded in T4 (p = 0.004, p = 0.01 and p = 0.02 and p = 0.001, respectively). Based on the polynomial regression analysis, the PKM inclusion at 26.17–100.11 g/kg can be effectively used in the diet of juvenile L. rohita as a non-conventional growth-promoting feed ingredient without any harmful effects on its growth performance and physiological activities.

The golden mahseer (Tor putitora) is an important and high valued sport and food fish of national and international importance. Therefore for promotion of golden mahseer, proper mineral supplementation in early developmental stages is very important. The present study evaluated the effects of dietary zinc on growth, survivaland physiological response of Tor putitora fry. One thousand eight hundred fry (avg.wt 54.35±3.09 mg) were randomly distributed into 6 treatment groups with triplicates each. Six iso-nitrogenous (40±0.02% to 41.44±0.01% crude protein) semi-purified diets were prepared with graded levels of dietary zinc. Zinc sulphate was added as the dietary zinc source to the basal diet. The results indicated that specific growth rate (SGR) was of value 2.52 ±0.23 gm of T. putitora fry which increased with dietary zinc levels up to a concentration of 40 mg Zn Kg-1 in diet. The zinc dependent metabolic enzymes and antioxidant enzymes was also observed to be highest in groups supplemented with 40 mg zinc/kg feed. The overall results of the present study suggest the efficacy of dietary zinc on growth, survival and physiological response of golden mahseer fry in order to garner the possibility of establishing the species to commercial aquaculture.

Lingam, S.S.; Sawant, P.B.; Chadha, N.K.; Pani Prasad, K.; Muralidhar, A.P.; Syamala, K., and Martin Xavier, K.A., 2019. Effect of duration of stunting on physiological recovery of stunted...

Heteropneustes fossilis (Bloch) is an important candidate species for diversification of freshwater aquaculture in India. However, high mortality rate during larval rearing is the most serious bottleneck in commercial production of this species. A proper understanding of the ontogenic development of digestive system provides the basis to understand the nutritional physiology of larvae and develop appropriate feeding strategies. In the present study, the ontogenical development of the digestive tract in H. fossilis larvae was studied from hatching until 30 day post-hatching (dph) at 29 °C. At hatching (2.8 ± 0.2 mm standard length, SL), the digestive tract was undifferentiated and attached dorsally to the yolk sac. At 1 dph (2.9 ± 0.2 mm SL), the mouth opened and oral valves were visible. At 2 dph (3.0 ± 0.3 mm SL), goblet cells were observed in the buccoparyngaeal cavity. At this age, exogenous feeding started and the intestine was differentiated into the anterior and posterior regions, and the rudimentary liver and pancreas were also seen. Small supranuclear vacuoles were observed in the enterocytes of the posterior intestine at 2 dph. Zymogen granules were observed in acinar cells of pancreas by 3 dph, and islets of Langerhans were visible at 4 dph (3.5 ± 0.1 mm SL). At the same age, most of the yolk sac reserves were consumed, whereas they were completely exhausted by 5 dph (3.9 ± 0.5 mm SL). Between 4 and 6 dph, the liver elongated in size and started to accumulate lipids in the hepatocytes. Gastric glands were detected at 4 dph, and the pyloric sphincter was completely differentiated at 9 dph (6.1 ± 0.4 mm SL) as an epithelial fold that separated stomach from the anterior intestine. By 13 dph (8.6 ± 0.2 mm SL), profuse gastric glands were visible inside longitudinal mucosal folds of the stomach. The formation of gastric glands and their development were noticed as the last events in the development of the digestive tract in H. fossilis. This indicated the end of the larval period and the commencement of the juvenile stage. Considering these observations, it is suggested that H. fossilis larvae have a morphologically complete digestive tract by 13 dph. The findings of the study on the development of the digestive system in H. fossilis may help in synchronising the larval stage of development and feeding strategies and would be helpful in improving larval rearing techniques for catfish species. info:eu-repo/semantics/acceptedVersion

Floodplain wetlands (beels) constitute one of the most important fishery resources amenable for culture-based fisheries development in Assam, both in terms of large resource size (100,815 ha) and high fish production potential (1000-1500 kg ha-1 yr-1). Pen aquaculture technology standardised by ICAR-Central Inland Fisheries Research Institute (ICAR-CIFRI), Barrackpore, India for in situ rearing of carp seed for stocking in beels was demonstrated in 21 beels located in 9 districts of Assam in collaboration with the Assam Fisheries Development Corporation Limited (AFDC Ltd.) and Bodoland Territorial Council (BTC) for pilot-scale validation of economic feasibility of the technology. Large pen enclosures (2400-4990 m2) were erected in the beels for the validation; which were grouped into four size groups viz., P1 (2400-2499 m2), P2 (2500-3499 m2), P3 (3500-4499 m2) and P4 (4500-4999 m2 area) to determine the most economic size of pens for the beels of Assam. Cost of bamboo (main construction material) ranged from 30.47 (P4) to 48.74% (P3) of the capital cost. Labour cost for pen construction was found to be the major contributor of capital cost ranging from 33.73 (P3) to 52.22% (P4), followed by the cost of LDPE netting (10.56-13.74%) and coir rope (3.28-5.83%). Major share of recurring cost was spent on fish seed (54.93-61.04%), followed by feed (17.01-22.63%) and towards labour for culture operations (8.48-14.51%). The total cost per crop was the highest in P3 (`87,211/-) followed by that in P4 (`52,606/-) and P2 (`50,933/-), whereas it was the lowest in P1 (`49,511/-). The percentage expenditure of recurring costs per crop to total cost was 72.48-82.25% and a much smaller percentage (17.74-27.51%) of total cost was contributed by the cost on fixed expenditure. The average quantity of fish seed produced in the pens in P1, P2, P3 and P4 groups was 885.94, 875.08, 1,356.73 and 1,104.62 kg, respectively. The P1 group was found to be the most economically viable pen size yielding the highest benefit-cost ratio (3.04), followed by pen sizes P4 (2.78), P2 (2.50) and P3 (2.28). The study showed that pen aquaculture technology using pen sizes in the range of 2400-5000 m2 were economically viable for in situ carp seed rearing in the beels of Assam, with highest profitability in the pen size range of 2400-2499 m2.

A 60-d growth trial was conducted with the black tiger prawn, Penaeus monodon (ca. 0.8 g juveniles) at CIFE Rohtak Centre to evaluate the effects of salinity and Na+/K+ ratio of inland saline water on shrimp growth, survival, and osmoregulation. Three different salinities (5, 10, and 15 ppt) and five different Na+/K+ ratios (25:1, 45:1, 65:1, 85:1, and 27.9:1), for a total of 15 treatments were prepared by ionic manipulation. The medium with Na+/K+ ratio 27.9 was reconstituted seawater and was used as the reference treatment. At the end of the 60-d trial both salinity and Na+/K+ ratio significantly influenced the survival and growth of shrimp in inland saline water (P 0.05) for mediums with Na+/K+ ratio 25, 45, 65, and 27.9 at all salinities. Significantly different (P

is a serious problem occurring in ponds or estuaries where fish culture is practised. A possible solution to this problem is to raise oysters in an integrated culture with fish to improve water clarity and to help remove excess nutrients. In order to determine the effects that cultured oysters have on the environment, an experimental study was performed in the Moothakunnam region of the Vembanad lake in the Ernakulam District during February-November, 2012. The study was performed in four cages (1× 1× 1 m) referred to as treatments T1, T2, T3 and T4. The four treatments used fish ( Etroplus suratensis ) and oysters (Crassostrea madrasensis) in the ratio of 1:0.3, 1:0.5, 1:0.7 and 1:0 respectively. Several parameters were measured and compared between the four treatments, and these included temperature, pH, salinity, dissolved oxygen, biochemical oxygen demand, chemical oxygen demand, total suspended solids, ammonia, nitrite, nitrate and orthophosphate. Results showed that the parameters, DO, BOD, COD, TSS, ammonia and orthophosphate varied with different treatments and months. However, the contents of nitrite and nitrate showed variation only with respect to months. The eutrophication index (E) values calculated for the four treatments were 9.45 ± 4.41, 5.25 ± 3.23, 11.32 ± 6.17 and 11.52 ± 5.45 respectively. The lower E value obtained was for T2 which supports the conclusion that oysters can control eutrophication in an integrated aquaculture system. The optimal co-cultivation proportion of fish to oysters obtained from the present study was 1:0.5.

Two species of marine sponges Stylissa massa and Liosina paradoxa were cultured in cages (in situ) and in land based aquaria (ex situ) over a period of 120 days. Growth and survival were evaluated using four substrates viz., tile, block, coral rock and rope) under both in situ and ex situ conditions. L. paradoxa in cages recorded significant increase (p

Occupational commitment is referred to as the psychological link between an individual and his occupation that is based on an affective reaction to that occupation. Thus a person with higher occupational commitment strongly identifies and has positive feelings towards his occupation. It has been observed that R&D professionals have a very distinctive nature in their career orientations, value systems, and reward preferences. In R&D organizations, due to complexity of tasks, the employee and the employer often do not understand the nature of the job performance and therefore commitment to occupation is seen as an important contributing factor. Hence, this study addresses the following research questions: How does occupational commitment differ with the different types of R&D organizations? How do personal demographic, job satisfaction, and personality variables influence occupational commitment of different types? This study empirically examines the relationship among the personal characteristics of R&D scientists across three types of R&D organizations: A government commercial organization A government defence organization A government academic organization. The objective is to find out the influence of age, occupational tenure, job satisfaction, and occupational commitment on the five factor model of personality. A questionnaire of job satisfaction followed by the neo five factor personality inventory and occupational commitment questionnaires were administered on a sample of 126 R&D professionals. The results of the analysis revealed that: Occupational commitment of scientists does differ in these different R&D organizations. Occupational tenure is much higher for the scientists of the government commercial R&D organization and the government academic R&D organization compared to the scientists of government defence R&D organization. Job-satisfaction is the highest amongst the scientists of the government defence R&D organization followed by the scientists of the government academic R&D organization. Personality scores of the scientists also differ across these three organizations. Occupational tenure and age are not related to personality. Affective commitment is shown to have a positive and significant relationship with conscientiousness for scientists of the government academic R&D organization. Affective commitment is explained by occupational tenure and extraversion while continuance commitment is explained by job satisfaction and agreeableness in the government commercial R&D organizations. Extraversion (factor of personality) emerged as the strongest predictor of affective commitment in the presence of conscientiousness, agreeableness, and neuroticism. For managers of R&D organizations, it is important to note that in the information-enabled world of today, occupational commitment rather than organizational commitment is likely to be the key variable in deciding whether to stay or leave.

Deccan mahseer (Tor khudree) has recently been included in the IUCN list of threatened species due to its declining population. Intervention of nutritional strategies for better growth and survival of early stages for grow out and ranching is essential. The present investigation intended to study the effect of various dietary combinations containing live and inert feed enriched with cod liver oil on growth and survival of Tor khudree first feeding fry, while effects on whole body fatty acid composition of fry were also studied. Cod liver oil as a source of essential fatty acids was used for enriching both live and inert formulated feed. The experimental design consist of four treatments viz. T0 (inert diet without enrichment), T1 (inert diet enriched with cod liver oil), T2 (inert diet enriched with cod liver oil+unenriched Artemia) and T3 (unenriched inert diet+enriched Artemia) fed to four distinct experimental groups for a period of 60 days. At the end of the experiment growth, survival and fatty acid profile of the fry were examined. Fry fed combination of unenriched inert diet and enriched Artemia (T3) had the highest growth and feed efficiency in terms of percentage weight gain (PWG), specific growth rate (SGR), average daily growth (ADG) and feed conversion ratio (FCR). Survival percentage was also significant in T3 compared to other groups. Enrichment of dietary components had a direct effect on the whole body fatty acid profile of mahseer fry with significant (P

Hypoxia is a global phenomenon affecting recruitment as well as the embryonic development of aquatic fauna. The present study depicts hypoxia induced disruption of the intrinsic pathway of programmed cell death (PCD), leading to embryonic malformation in the goldfish, Carrasius auratus. Constant hypoxia induced the early expression of pro-apoptotic/tumor suppressor p53 and concomitant expression of the cell death molecule, caspase-3, leading to high level of DNA damage and cell death in hypoxic embryos, as compared to normoxic ones. As a result, the former showed delayed 4 and 64 celled stages and a delay in appearance of epiboly stage. Expression of p53 efficiently switched off expression of the anti-apoptotic Bcl-2 during the initial 12 hours post fertilization (hpf) and caused embryonic cell death. However, after 12 hours, simultaneous downregulation of p53 and Caspase-3 and exponential increase of Bcl-2, caused uncontrolled cell proliferation and prevented essential programmed cell death (PCD), ultimately resulting in significant (p

The present study was undertaken to evaluate the effect of a probiotic strain, Bacillus circulans (BC) and prebiotics fructooligosaccharide (FOS) supplementation in Labeo rohita fingerlings subjected to sub-lethal nitrite stress. Earlier a sixty days feeding trial was conducted using eight experimental diets viz. T1 (106 cfu/g BC+0%FOS), T2 (108 cfu/g BC+0% FOS), T3 (0BC+1%FOS), T4 (0BC+2%FOS), , T5 (106 cfu/g BC + 1% FOS), T6 (106 cfu/g BC+2% FOS), T7 (108 cfu/g BC+1%FOS), T8 (108 cfu/g BC+2%FOS) & control (0BC+0%FOS) assigned to triplicate groups. After the initial experiment, fishes were subjected to sub-lethal nitrite (1/5 96 h LC50 = 2.08 mg/L) for another 30 days. At the end of the experiment growth and feed utilization parameters viz. weight gain, specific growth rate (SGR), feed conversion ratio (FCR) & survival percentage were calculated. Haemato-immunological parameters viz. total leukocyte count (TLC), total erythrocyte count (TEC), hemoglobin (Hb), hematocrit (Hct) values, lysozyme and respiratory burst activity were assayed after exposure to stress. Growth and feed utilization was significantly (p < 0.05) better in probiotic fed groups at all level of supplementation whereas prebiotics supplementation at 2% level had negative impact. Percentage survival was also better in the supplemented groups with highest survival observed in T4 group. Similarly, post challenge haemato-immunological parameters were better in supplemented group compared to control and higher levels were observed in combination groups (T4 and T5). From the present investigation, it can be concluded that probiotic B. circulans and prebiotics FOS supplementation improves immune status and thereby conferring better protection of L. rohita under sub-lethal nitrite stress.