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This paper describes a filleting machine designed for the popular Asian freshwater species rohu (Labeo rohita). The machine comprises three key units: conveying, filleting, and water spraying and collection. The filleting unit has two parallel disc blades for precise cutting, with adjustable spacing to accommodate a variety of fish backbone thicknesses. The conveying unit employs belt drives and spring-adjusted entry for smooth transport, while the water management unit sprays and cleans the filleting blades, ensuring efficient fish movement. The machine performed efficiently when set to its optimal settings and showed significant improvements compared to manual filleting while maintaining product quality. [ABSTRACT FROM AUTHOR]

Bisphenol F (BPF) is an emerging contaminant extensively used in the pharmaceutical, chemical, and food industries, exerting deleterious effects on human and wildlife health. Therefore, the current study was conducted to assess the toxicity induced by BPF in rohu Labeo rohita using multiple biomarkers such as oxidative stress, activity of antioxidant enzymes, biochemical parameters, histology, and genotoxicity. Fish were separated into four groups (T1–T4). Group T1 served as a control (0 μg/L), while Groups T2, T3, and T4 were exposed to BPF concentrations of 600 μg/L, 1200 μg/L, and 1800 μg/L, respectively, for 21 days. Results showed a significant (p < 0.05) increase in oxidative biomarkers (thiobarbituric acid reactive substance [TBARS] and reactive oxygen species [ROS]), while the concentration of antioxidant biomarkers (peroxidase [POD], superoxide dismutase [SOD], reduced glutathione [GSH], and catalase) was significantly (p < 0.05) decreased with the rising concentration of BPF in the liver, gills, and kidney of fish. Significant reduction (p < 0.05) in biochemical parameters was measured from collected whole blood, including red blood cells (RBCs), hemoglobin (HGB), mean corpuscular HGB (MCH), MC volume (MCV), hematocrit (HCT), MC HGB concentration (MCHC), platelets, low‐density lipoprotein (LDL), cholesterol, high‐density lipoprotein (HDL), total proteins, very LDL (VLDL), albumin and globulin, while white blood cells (WBCs), neutrophils, triglycerides, aspartate aminotransferase (AST), blood glucose, and alanine transaminase (ALT) levels were increased significantly (p < 0.05). Comet assay showed the DNA damage potential of BPF in erythrocytes. Histological examination showed that exposure to BPF causes several degenerative effects in the soft tissues (gills, liver, and kidney) of treated fish. It is concluded that BPF induces deleterious effects via disruptions in histological, genotoxic, and biochemical alterations in several organs of exposed fish. [ABSTRACT FROM AUTHOR]

Rohu fish (Labeo rohita) fillets were coated with 2.5% to 25% soy protein isolate (SPI) to evaluate their ability to reduce fat uptake. The coating pickup of fish fillets increased with increasing coating concentration. Fillets coated with 15% SPI showed the highest coating pickup value of 18.29% and reduced fat uptake by 57.78%. As revealed by lowered carbonyl and sulfhydryl contents, SPI coating protected proteins from oxidation during deep-frying. Increasing coating concentration decreased the hardness, chewiness, and cutting force of coated fish fillets. Therefore, the aforesaid coatings could be recommended for making low-fat fried fish fillets with 15% SPI. [ABSTRACT FROM AUTHOR]

In the 20th centuary, the economically important carp species Labeo rohita, Tor tor, & Labeo calbasu and the catfishes Rita rita & Bagarius bagarius contributed substantially to the total fish catch from the Ganga River system in India. Samples were recorded between December 2003 and June 2004 from fish landing centers in the Ken, Paisuni, and Tons rivers for L. rohita, T. tor and L. calbasu. Rita rita and B. bagarius were sampled between September 2001 and September 2003 in the Ganga River system. The data were used to evaluate the growth and age structures of fish populations. Age classes varied 0+-5+ for L. rohita in the Ken & Paisuni rivers and 0+-8+ in the Tons River. For T. tor, the age classes varied 1+-6+ in the Ken & Paisuni rivers and 1+-8+ in the Tons. Age classes of L. calbasu varied 1+-6+ in the Ken River, 1+-5+ in the Paisuni River, and 1+-7+ in the Tons. In the Ganga River, age classes of R. rita & B. bagarius varied 0+-7+ and 0+-6+, respectively. The L. rohita, age pyramid showed a tendency for bell shape in Ken River, base tends to be broader through bell shape in Paisuni River, and bell-shaped age pyramid was slightly distorted in Tons River. In case of T. tor, tendency for bell shape in Ken River and bell-shaped age pyramid in Paisun River & Tons River were obtained. In case of L. calbasu, heavy bottom shaped age pyramid was recorded in Ken and Paisuni rivers, while base tends to be broader in the Tons River. Bell shaped age pyramid was recorded for B. bagarius in the Ganga River while heavy bottom shape for R. rita in the Ganga River. Overall, T. tor is facing heavy fishing pressure and also targeted fish species by fishermen from the Ganga River system. [ABSTRACT FROM AUTHOR]

The bioaccumulation of trace elements and heavy metals in aquatic organisms is a critical environmental concern due to its potential impact on ecosystem health and human safety. This study investigated the level of trace elements and heavy metals bioaccumulation in Labeo rohita and Mystus seenghala from the River Jhelum in the district Khushab, Punjab, Pakistan. The concentration of calcium, magnesium, iron, nickel, copper, arsenic, cadmium, zinc, chromium, manganese, cobalt, and lead in the gills, liver, and muscle tissues of these fish was measured using inductively coupled plasma-mass spectrometry. Then, the extent of contamination and its possible health risks were assayed. Our findings indicate significant variations in the elemental and metal concentrations among different organs and between species, reflecting their diverse feeding habits and habitats. The health risk assessment based on the estimated daily intake, estimated weekly intake, maximum permissible intake, target hazard quotient, hazard index or total target hazard quotient, health risk index, and target cancer risk revealed potential risks to human consumers of these fish. This study emphasizes the need for continuous monitoring, as new data and insights are crucial for understanding and mitigating these risks. Strict regulatory measures are also necessary to safeguard public health and preserve the ecosystem of Jhelum River. [ABSTRACT FROM AUTHOR]

ABSTRACT The present study was carried out to isolate, identify, and characterize bacterial probiotic strain from the gut of Ctenopharyngodon idella (Grass carp) and then to study its effect on growth, digestive enzymes and immunity of Labeo rohita fingerlings. A total of 6 gram‐positive bacteria belonging to the genus Lactobacillus spp. (3), Bacillus spp. (2) and Staphylococcus spp. (1), were identified biochemically. Based on the biochemical results, the isolate GCLP4 was selected for molecular confirmation and BLAST analysis showed maximum homology with Lactobacillus plantarum (100% ident). Fish were fed for 60 days with diet containing 0 (T0), 105 (T1), 107 (T2), 109 (T3) cfu/g diet of L. plantarum GCLP4 and 105 (T4) of commercial probiotics. Results shows that supplementation of GCLP4 had significantly (p < 0.05) improve weight gain (%), specific growth rate (SGR) and feed conversion ratio (FCR) of L. rohita with better values in T3 group. The immunological parameters (white blood cell, red blood cell, haemoglobin, total protein, albumin and globulin were significantly higher (p < 0.05) with 107 and 109 Lactobacillus GCLP4 cfu/g diet. The digestive enzyme activities (protease, amylase and lipase) were significantly (p < 0.05) higher, particularly, with 109 Lactobacillus GCLP4 cfu/g of diet. All the groups supplemented with GCLP4 including the commercial probiotics have lower (p < 0.05) activities of serum transaminase enzymes along with lower (p < 0.005) level of glucose as compared to the control group. The results of the study collectively suggest that dietary L. plantarum GCLP4 at 109 cfu/g is an effective probiotic obtained from grass carp having potency to promote growth, digestive enzymes and immune‐biochemical indices of L. rohita fingerlings in present culture condition. [ABSTRACT FROM AUTHOR]

This study examined the concentrations of seven heavy metals (Pb, Cu, Zn, Cr, Cd, Ni, and Mn) in the muscle tissue of six commonly consumed fish species (Cyprinus carpio, Labeo rohita, Wallagu attu, Hypophthalmicthys molitrix, Channa punctuate, and Puntius sophore) from the River Indus in the Mianwali district Pakistan. Samples were collected during both pre-monsoon and post-monsoon seasons to assess the potential human health risks associated with these heavy metals. The levels of metals were measured using atomic absorption spectroscopic analysis. The results showed varying concentrations of heavy metals in the fish samples (mg/kg), ranging from 10.17-2.06 for Pb, 41.83-12.54 for Cu, 417.04-41.93 for Zn, 2.06-0.46 for Cr, 0.86-0.08 for Cd, 4.33-1.43 for Ni, and 50.16-8.74 for Mn. Notably, metal concentrations were generally higher during the pre-monsoon season, with Pb consistently exceeding standard limits in the muscle tissue of all fish species. ANOVA analysis revealed significant variations in heavy metal concentrations among different fish species. While the current consumption rate poses no significant health risks, ongoing monitoring of heavy metal concentrations in fish and their environmental sources is crucial to ensure consumer safety and sustainable aquatic ecosystems. [ABSTRACT FROM AUTHOR]

Present study aimed to evaluate the dietary impact of commercial zinc oxide (ZnO) nanoparticles (NPs) on the growth performance of commercially important fish fingerlings. A 90-days feeding trial was carried out to evaluate the impact of dietary supplementation of commercial ZnO-NPs on the growth performance and survival rate of commercially important fish of carp family-rohu (Labeo rohita) fingerlings (2.23±0.38g in average weight and 5.74±0.28 cm in average length). ZnONPs (Sigma-India) supplemented feed was prepared at a concentration (10, 100, 200 mg/kg) and experimental fish fingerlings were exposed for 90 days. Mid-term, fish fingerlings were randomly sampled every 30 days from both the dietary exposed and unexposed groups to assess growth parameters, including weight gain (WG), weight gain percentage (WG%), specific growth rate (SGR), and feed conversion ratio (FCR). After 90 days of feeding, the results indicated that the ZnO inclusion diet at a concentration of 100 mg/kg significantly improved growth performance, with a weight gain of 5.50±0.51g, weight gain percentage of 143.6±53.22%, and FCR of 1.41±0.32, compared to other treatment and control groups. [ABSTRACT FROM AUTHOR]

The aquatic environment, independent of their host, is more favorable to pathogenic bacteria than the terrestrial environment. Consequently, pathogenic bacteria can reach very high densities around aquatic animals and can cause high mortality. The conventional approach, such as antibiotics, has minimal effectiveness. Additionally, due to the emergence of (multiple) resistance, their use is under intense scientific and public scrutiny. Hence, there is a need for the development of alternative control techniques, with an emphasis on prevention, which is likely to be more cost-effective. In this study, a potential bacterial strain Cytobacillus firmus was isolated from polluted river sediment and characterized using a comprehensive range of techniques including biochemical, 16S rRNA sequencing and antibiogram assay. The pathogenicity of the bacteria was tested in vivo on Labeo rohita fingerlings found as non-pathogenic. Further, the bacteria were found to synthesize silver nanoparticles (AgNPs) using AgNO3 as a substrate. The obtained AgNPs were characterized by various methods, including UV-vis spectroscopy, FTIR (Fourier-transform infrared spectroscopy), and Transmission Emission Microscopy (TEM). The study found that the AgNPs were 20 nm in size on average. The antimicrobial activity of synthesized AgNPs was examined against the model freshwater pathogenic bacteria, Edwardsiella tarda and both the MIC (Minimum Inhibitory Concentration) and MBC (Minimum Bactericidal Concentration) were 0.156 µM, while biofilm inhibition activity was also observed at 0.156 µM. The AgNPs showed no haemolytic activity at 0.313 µM. Our findings suggest that C. firmus mediated bacteriogenic AgNPs modulate the activity of common pathogenic bacteria E. tarda. The thoroughness of our research process gives us confidence in the potential of applying AgNPs in aquaculture as a considerable strategy to control the E. tarda infection. [ABSTRACT FROM AUTHOR]

Fish substitution in fish products is an important issue in fish markets, as it is a widespread practice. An authentication protocol for Rohu, Thaila and Tilapia was developed by multiplex PCR. Three species-specific and one degenerate common forward primer were designed using the Cytb gene of the mitochondrial genome. These primers for Labeo rohita, Labeo catla and Oreochromis niloticus showed the fragment size of 235 bp, 186 bp and 506 bp on the agarose gel, respectively. The primers for L. rohita and L. catla were sensitive to 0.1 ng of DNA template, while for O. niloticus this value was 1 ng of DNA template. A total of 230 commercial samples (160 fried and 70 processed fish products) were screened, where 60% mislabeling in fried and 30% mislabeling in processed fish were found. This multiplex PCR protocol could give useful insights for food inspection and enforcement of regulatory food control. [ABSTRACT FROM AUTHOR]

There is a considerable interest in supplementing fish diets with bio-functional substances such as polyunsaturated fatty acids (PUFAs), and research is being conducted to evaluate their effects on fish physiology, particularly on breeding performances. The objective of this study was to find out how squid-derived lipids (PUFAs) influence the Rohu carp, Labeo rohita, in terms of reproduction, and embryonic and larval growth. The experimental fish were provided with formulated diet for a duration of 90 days, containing 1 % squid-extracted lipids as a primary source of polyunsaturated fatty acids (PUFAs). To determine the accuracy of the formulation, a proximate analysis of the feed ingredients and the formulated feeds were conducted. The results demonstrated remarkable reproductive outcomes during the spawning trial. Observations in fish treated with PUFAs revealed a significant improvement (p < 0.001) in sperm quality and viability, despite spawning occurring late in the breeding season. In addition, the fertilization rate (92.27 ± 1.74), hatching rate (89.33 ± 1.76), and survival rate (85.83 ± 1.74) of the offspring exhibited a statistically significant increase (p < 0.05) when subjected to PUFAs treatment in L. rohita. Consequently, the treated fish exhibited enhanced early embryonic and larval development in comparison to the control group. Hence, the current study demonstrates that the inclusion of PUFAs in the diet of Rohu carp leads to improved maturation, breeding, and developmental outcomes, specifically in terms of embryonic development and organogenesis. [ABSTRACT FROM AUTHOR]

Background: Fishes being major sources of protein are susceptible to post-harvest losses. Appropriate processing and preservation makes food healthier, safer, tastier, and more shelf-stable. Therefore, an attempt was made to evaluate the effectiveness of different processing and preservation technologies on keeping quality of Labeo rohita (rohu fish), a widely found ray-finned species in South Asia that is important for aquaculture. Methods: Raw fish fillets were subjected to different processing and preservation technologies including freezing, sun drying, mechanical drying, salting, microwave processing, and marinating to determine their effects on keeping quality. Consequently, sensorial attributes, proximate composition, mineral (calcium (Ca), iron (Fe), and zinc (Zn)) contents and microbiological analyses were carried out. Obtained data were analyzed statistically and compared using one-way analysis of variance (ANOVA) followed by Fisher's LSD test at 5% level of significance. Results: The moisture, protein, fat, ash, and carbohydrate contents were 13.01-77.29, 8.62- 52.57, 0.86-18.69, 1.34-12.72, and 1.13-27.22%, respectively in different processing and preservation technologies. Drying manifested to be the efficient method in terms of preserving proteins and fats while retention of sensory attributes was obtained in freezing. The contents of Ca, Fe, and Zn were 120.05-227.97, 0.54-1.14, and 0.72-2.04 mg/100 g, respectively. In addition, maximum retention of Zn, Fe, and Ca contents were observed in freezing, sun drying, and marinating, respectively. Furthermore, total bacterial count was in the range of 0- 2.6×104 Colony Forming Unit (CFU)/g and no coliforms were detected in any of the raw and processed fish fillets. Results of microbiological study revealed that microwave processing is highly efficient to reduce microbial loads in processed fish. Conclusion: Combination of different processing and preservation technologies might be useful to the efficient management of fishery resources. Therefore, further research into these combinations is essential to ensure that the nutritional value of fish is preserved. [ABSTRACT FROM AUTHOR]

The present study was undertaken to evaluate cypermethrin (CYP)-induced oxidative stress [reactive oxygen species (ROS) and lipid peroxidation (LPO) in gills, muscles, brain, and liver tissues] and DNA damage/genotoxicity (peripheral blood erythrocytes) in a freshwater teleost rohu (Labeo rohita) and the protective role of vitamin C. The LC50 of CYP against rohu was found to be 4.5 µg/L in a semi-static culture system through probit analysis. Fingerlings of rohu were distributed into four groups (Group 1st served as a control, fed 35% protein basal diet and was not exposed to CYP; Group 2nd was fed a basal diet and exposed to CYP; Group 3rd and Group 4th were fed diets supplemented with vitamin C at the rate of 100 and 200 mg/kg diet, respectively, and exposed to CYP). Fingerlings were reared on a basal and vitamin C-supplemented diet for 28 days prior to exposure to CYP. The results indicate a time-dependent significant increase in ROS and LPO (indicated by time course increase in TBARS level) as well as DNA damage in terms of number of comets, % DNA in tail, tail moment, tail length, and olive tail moment after exposure to LC50 of CYP. However, statistically comparable results in both Groups 1st and 4th indicate the protective role of vitamin C. The results reveal the effectiveness of vitamin C as a feed additive for countering pesticides toxicity in Labeo rohita. The current study indicates CYP as a potential genotoxicant for fish and classifies SCGE as a reliable and sensitive tool for assessing DNA damage. [ABSTRACT FROM AUTHOR]

A 60 days study was conducted to evaluate the physiological response of indigenous species Labeo rohita (LR) and indigenous predator Chitala chitala (CC) in presence of an invasive species Piaractus brachypomus (PB). Two treatment groups as LR + PB (T1) and LR + PB + CC (T2) with individual control groups as T0LR, T0PB and T0CC were designed in triplicates. Fingerlings of LR, PB and CC were randomly distributed into 15 circular tanks with a stocking ratio of 1:1 and 1:1:0.3 in T1 and T2 group, respectively and 10 nos. each of LR, PB and CC in respective control groups. At first 15 min of the experiment, cortisol level was found significantly (P < 0.05) higher in all three experimental fishes in T1 and T2 groups. With the experimental duration, the level of stress hormone (cortisol), oxidative stress enzymes (superoxide dismutase, catalase, and glutathione peroxidase), tissue metabolic enzymes (lactate dehydrogenase and malate dehydrogenase), serum metabolic enzymes (transaminase enzymes) and blood glucose level were significantly (P < 0.05) increased in T1 and T2 groups for LR and CC whereas, no variation (P > 0.05) were observed for PB in both T1 and T2 groups. The total antioxidant capacity (TAC), liver glycogen, total protein, albumin and globulin were found to be significantly (P < 0.05) decreased in LR in the presence of PB and CC. The present study provides a preliminary insight into the biological interaction between native and invasive species and their physiological responses in the presence of native predator with higher trophic index. Thus, the results of the study suggest the superior traits of invasive P. brachypomus try to dominate the other two native species by negatively influencing the native fauna even with a higher trophic index (C. chitala). [ABSTRACT FROM AUTHOR]

Among xenobiotics, metals gained attention because of their toxicity and harmful effects on aquatic ecosystems, fish and human health. Present research work focused on the toxicological effects of hexavalent chromium on the DNA of three major carps viz. Cirrhina mrigala, Labeo rohita and Catla catla by using the comet assay. All three fish species were exposed to four sub-lethal concentrations (2/3rd, 1/3rd, 1/4th and 1/5th of LC50) of chromium for six exposure durations (14, 28, 42, 56, 70 and 84 days). All three fish species exhibited significantly variable exposure dose and time dependent DNA damage in terms of damaged nuclei, GDI and CTL in their erythrocytes. Among the fish species, C. mrigala showed maximum DNA damage with the highest damaged nuclei (44.28±25.97%), GDI (1.52±0.84) and CTL (126.91±75.71 µm), whereas significantly lower DNA damage was observed in C. catla. At various exposure durations, DNA damage was observed to be significantly higher at 56 days of exposure which then reduced afterward, however, at various exposure concentrations of chromium, maximum DNA damage was observed at 2/3rd of LC50 of metal followed by 1/3rd, 1/4th and 1/5th of acute toxicity of chromium for all three fish species under study. [ABSTRACT FROM AUTHOR]

Over the past two decades, there has been a growing alarm about the role of unintended hybridization in shaping the current biodiversity. Major carps (Labeo rohita, Catla catla, and Cirrhina mrigala) are commercially important freshwater fish for aquaculture and are also found exclusively in the riverine ecosystems of Punjab, Pakistan. One of the main concerns is the genetic integrity of major carps. In this study, we employed both nuclear and mitochondrial DNA markers to determine the potential hybridization and patterns of genetic variation in major carps. Association tests of both nuclear and mtDNA markers provide evidence of recent hybridization, and patterns of genetic variations were also found consistent with observed pattern of admixture in major carps. In all hybridization events, L. rohita is detected to hybridize with C. catla and C. mrigala, whereas C. catla and C. mrigala are established to hybridize with L. rohita. Overall, two levels of hybridization; F1 hybrids reported in hatchery-reared stocks and few backcrosses individuals in wild populations suggest that anthropogenic or demographic dynamics accelerate inter-generic gene flow. Moreover, the disparity in amplified mtDNA COI subunit shows strong directional bias towards Labeo–Catla first-generation hybrids (100%) containing L. rohita maternal lineage while Labeo-Cirrhina hybrids (75%) exhibit C. mrigala maternal lineage. The results of this study endorse that culture-based fish farming and restocking activities of major carps in riverine ecosystems demand regular genetic monitoring of these species. The current genetic evidence and proclamation of practical information should encourage management and conservation efforts to strictly limit the genetic integrity of these species. [ABSTRACT FROM AUTHOR]

Paraprobiotics, non-viable versions of probiotic microorganisms, offer a promising prophylactic strategy in aquaculture, addressing concerns about the safety and functionality of probiotics while harnessing similar health benefits for fish and shellfish. This study determined the dietary effects of paraprobiotic preparation from Bacillus amyloliquefaciens COFCAU_P1 to support the immune system and control Aeromonas hydrophila infection in Labeo rohita fingerlings. Paraprobiotic was prepared by heat and formalin inactivation of the probiotic B. amyloliquefaciens and subsequently analyzed by scanning electron microscopy. The cellular immunological responses viz. superoxide anion, myeloperoxidase activity, nitric oxide production, and leucocyte proliferation of rohu head-kidney (HK) leucocytes increased significantly with different doses (106, 107, and 108 cells ml−1) of both heat and formalin-inactivated preparations in vitro. Both preparations significantly enhanced the in vitro immune gene (IL-1β and IFN-γ) expression, indicating their immunostimulatory response at the molecular level. As the formalin-inactivated preparation showed a better immune response, it was selected for the subsequent in vivo experiment. Dietary administration of formalin-inactivated B. amyloliquefaciens at different doses (106, 107, and 108 cells g−1 feed) showed significantly higher responses in innate immune (respiratory burst, myeloperoxidase, and anti-protease activity) and biochemical parameters (total protein, albumin, globulin alkaline phosphatase activity, and glucose content). Resistance against experimental A. hydrophila infection was increased significantly after 30 days of feeding of the formalin-inactivated B. amyloliquefaciens. At the paraprobiotic dose of 1 × 108 cells g−1 feed, the maximum immune response and survivability against A. hydrophila infection were observed. It can be inferred from the results that formalin-inactivated B. amyloliquefaciens paraprobiotic can be used as a promising immunostimulant in aquaculture. The potency of B. amyloliquefaciens paraprobiotic to enhance immunity and survivability of rohu against experimental A. hydrophila infection is worth mentioning. [ABSTRACT FROM AUTHOR]

The present study assessed the possible interaction of saponins with the phenolic antinutritional factor tannin and the animal-origin diet component, cholesterol, in the context of plant-based aquafeed formulation with the addition of cholesterol. An in vitro analysis evaluated the ability of saponin to neutralize cholesterol and tannin. The results revealed that the neutralizing capacity of cholesterol and tannin at 0.5% saponin concentration was 49.84% and 40.32%, respectively. In the second experiment, a feeding trial was conducted for 45 days in Labeo rohita fingerlings. Twelve fish each (average weight 5.28 ± 0.34 g) were randomly distributed into six treatment groups in triplicates. Six iso-nitrogenous (30% CP) and isolipidic (6%) purified diets were prepared: control (C), saponin (CS; C + 0.5% saponin), cholesterol (CC; C + 1% cholesterol), tannin (CT; C + 1.25% tannin), saponin and cholesterol (SC; C + 0.5% saponin and 1% cholesterol), and saponin and tannin (ST; C + 0.5% saponin and 1.25% tannin). The group fed 0.5% saponin and 1% cholesterol showed the maximum weight gain (%), specific growth rate, and protein efficiency ratio with the lowest FCR value, which was similar (P > 0.05) to the control. The addition of tannin (1.25%) to the saponin (0.5%) containing diet (ST group) partially restored growth performance. The HSI value significantly increased due to the feeding of saponin but decreased in the SC and ST groups compared to the saponin-fed (CS) group. The blood parameters like hemoglobin content, RBC, and leucocyte counts were higher (P < 0.05) in the SC and ST groups compared to the CS group, although significantly (P < 0.05) lower than that of the control (C) group. Serum total protein, albumin, and globulin values in the CS group decreased but improved in the SC and ST groups. Serum transaminase enzymes (SGPT, SGOT), total bilirubin, and creatinine were increased in the saponin-fed CS group but reduced in the SC and ST groups. In conclusion, saponins had an unambiguous interaction with tannin and cholesterol in both in-vitro and in-vivo conditions. Further, adding (1%) cholesterol into saponin (0.5%) containing aqua-feeds can negate the effect of saponin. [ABSTRACT FROM AUTHOR]

Chitosan preparation is a sequential method that involves demineralization and deproteinization followed by deacetylation. In the present study, the effect of different process parameters such as concentration of acid, concentration of alkali, ratio between solid and solvent, reaction time, and temperature for optimization of demineralization and deacetylation processes in chitosan synthesis from Labeo rohita scale was studied. The effects of the above process parameters on chitosan yield (in terms of dry weight and % of moist weight of mass) were carried out using Box–Behnken design (BBD) of response surface methodology (RSM). The optimum condition for demineralization was observed at the ratio of solid to solvent (w/v) of 80 and incubation time of 10 min. Similarly, the optimum condition for deacetylation was revealed at alkali concentration of 15% and incubation time of 20 min. The obtained chitosan is characterized by UV–Visible spectroscopy, FT-IR analysis, SEM, and X-ray diffraction. [ABSTRACT FROM AUTHOR]

The present investigation examined the potential of a previously identified probiotic derived from the intestinal tract of Labeo rohita to modulate the immune system and confer disease resistance when included in a basic diet. The viability of B. subtilis in the feed was assessed at both 4 °C and 28 ± 2 °C, revealing no notable changes. A total of 180 L. rohita fingerlings (19.27 ± 1.96 g) were randomly distributed in four groups (one control and three probiotic-treated groups in triplicate) and fed with the basal (the control) and B. subtilis–supplemented diets (at a concentration of 107, 108, and 109 CFU g−1) over a period of 20 days. Immunological responses, biochemical parameters, and immune-relevant gene expression (interleukin 1β (IL-1β), interferon 1γ (IFN-1γ)) relevant to immunity were analyzed on the 0, 10th, and 20th day post-feeding. In a separate but similar setup, probiotic-fed fish were intraperitoneally challenged with Aeromonas hydrophila (ATCC 7966), and their post-challenge survivability was calculated. After the 20-day feeding period, a significant (P < 0.05) improvement in immune-biochemical response and immune gene expression was evident. Serum glucose and sodium levels exhibited a significant (P < 0.05) decrease. The inclusion of B. subtilis in the diets led to a substantial (P < 0.05) increase in the survival of A. hydrophila–challenged L. rohita, thereby highlighting the potential of B. subtilis COFCAU_BSP3 as a beneficial probiotic for aquaculture. [ABSTRACT FROM AUTHOR]

This study investigated the production performance, household fish consumption, and commercial feasibility of prawn–carp–mola mixed gher farming system. Three treatments with different species compositions were compared: prawn + rohu, prawn + mola, and prawn + rohu + mola, each having different stocking densities. The results indicated that the integration of mola improved the utilization of feed protein by prawns. However, mola inclusion did not significantly affect the growth of prawn and rohu or the production system's cost. Mola inclusion led to a significant increase in the gross production, household consumption, and sale of mola, prawn, and rohu. It also increased gross returns, income above variable cost, and net returns to land, family labor, and management. In addition, the inclusion of mola significantly increased household consumption by increasing the intake of nutrient‐rich mola and overall fish consumption. This improvement in food consumption contributed to ensuring the nutritional requirements and food security of impoverished rural farmers, especially women and children. Consequently, the integration of small fish mola in prawn–carp gher farming systems is recommended as a beneficial practice for wider adoption, effectively addressing household nutrition security at the rural level and improving the livelihoods of farmers. [ABSTRACT FROM AUTHOR]

Silver nanoparticles (AgNPs) have garnered significant global attention from researchers due to their unique physicochemical properties and wide-ranging applications in industry and medicine. However, their release into aquatic ecosystems has raised concerns regarding potential ecotoxicological consequences. The present study investigated the effects of polyvinyl pyrrolidone-coated silver nanoparticles on Labeo rohita fingerlings, focusing on behavioural reactions, genotoxic effects, histological changes and bioaccumulation. L. rohita fingerlings were exposed to polyvinyl pyrrolidone-coated silver nanoparticles with sizes ranging from 18 to 29 nm for 7 days at concentrations of 100, 200, 400 and 800 ug/l. The nanoparticle zeta potential was found to be extremely negative, measuring − 55.5 mV for 18 nm and − 31.4 mV for 29 nm. Behavioural abnormalities, including respiratory distress, reduced responsiveness and erratic swimming, were observed in exposed groups compared to controls, with severity increasing with higher nanoparticle concentrations. Genotoxicity assessment revealed significantly higher DNA damage in kidney cells compared to gill cells. Histological examination of gill tissues showed clogging in primary and secondary lamellae, along with distorted anatomy, necrosis and vacuolar atrophy in peripheral tubules of the kidneys. The kidneys exhibited greater nanoparticle accumulation than the gills with prolonged exposure. Moreover, 18 nm AgNPs induced more pronounced DNA damage and histological alterations in the kidney and gill tissues compared to 29 nm nanoparticles. This study elucidates the critical role of monitoring AgNPs in aquatic systems, providing essential data on their behaviour and environmental impacts. The findings highlight the need for improved detection techniques and effective management of AgNP contamination. Future research should focus on developing more sensitive analytical methods, understanding long-term ecological effects and exploring innovative remediation strategies. [ABSTRACT FROM AUTHOR]

Introduction: STAT1a is an essential signal transduction protein involved in the interferon pathway, playing a vital role in IFN-alpha/beta and gamma signaling. Limited information is available about the STAT protein in fish, particularly in Indian major carps (IMC). This study aimed to identify and characterize the STAT1a protein in Labeo rohita (LrSTAT1a). Methods: The full-length CDS of LrSTAT1a transcript was identified and sequenced. Phylogenetic analyses were performed based on the nucleotide sequences. The in-vivo immune stimulant poly I: C was used to treat various tissues, and the expression of LrSTAT1a was determined using quantitative realtime polymerase chain reaction (qRT-PCR). A 3D model of the STAT1a protein was generated using close structure homologs available in the database and checked using molecular dynamics (MD) simulations. Results: The full-length CDS of Labeo rohita STAT1a (LrSTAT1a) transcript consisted of 3238 bp that encoded a polypeptide of 721 amino acids sequence was identified. Phylogenetic analyses were performed based on the nucleotide sequences. Based on our findings, other vertebrates share a high degree of conservation with STAT1a. Additionally, we report that the in vivo immune stimulant poly I: C treatment of various tissues resulted in the expression of LrSTAT1a as determined by quantitative real-time polymerase chain reaction (qRT-PCR). In the current investigation, treatment with poly I: C dramatically increased the expression of LrSTAT1a in nearly every organ and tissue, with the brain, muscle, kidney, and intestine showing the highest levels of expression compared to the control. We made a 3D model of the STAT1a protein by using close structure homologs that were already available in the database. The model was then checked using molecular dynamics (MD) simulations. Consistent with previous research, the MD study highlighted the significance of the STAT1a protein, which is responsible for Src homology 2 (SH2) recognition. An important H-bonding that successfully retains SH2 inside the STAT1a binding cavity was determined to be formed by the conserved residues SER107, GLN530, SER583, LYS584, MET103, and ALA106. Discussion: This study provides molecular insights into the STAT1a protein in Rohu (Labeo rohita) and highlights the potential role of STAT1a in the innate immune response in fish. The high degree of conservation of STAT1a among other vertebrates suggests its crucial role in the immune response. The in-vivo immune stimulation results indicate that STAT1a is involved in the immune response in various tissues, with the brain, muscle, kidney, and intestine being the most responsive. The 3D model and MD study provide further evidence of the significance of STAT1a in the immune response, specifically in SH2 recognition. Further research is necessary to understand the specific mechanisms involved in the IFN pathway and the role of STAT1a in the immune response of IMC. [ABSTRACT FROM AUTHOR]

Lindane is a broad-spectrum insecticide widely used on fruits, vegetables, crops, livestock and on animal premises to control the insects and pests. The extensive use of pesticides and their residues in the soil and water typically join the food chain and thus accumulate in the body tissues of human and animals causing severe health effects. The study was designed to determine the toxicity effects of sub-lethal concentrations of lindane on hemato-biochemical profile and histo-pathological changes in Rohu (Labeo rohita). A significant increase in the absolute (p<0.05) and relative (p<0.05) weights was observed along with severe histo-pathological alterations in liver, kidneys, gills, heart and brain at 30μg/L and 45μg/L concentration of lindane. A significant (p<0.05) decrease in RBCs count, PCV and Hb concentration while a significant (p<0.05) increased leukocytes were observed by 30μg/L and 45μg/L concentrations of lindane at 45 and 60 days of the experiment. Serum total protein and albumin were significantly (p<0.05) decreased while hepatic and renal enzymes were significantly (p<0.05) increased due to 30μg/L and 45μg/L concentrations of lindane at days-45 and 60 of experiment compared to control group. The observations of thin blood smear indicated significantly increased number of erythrocytes having nuclear abnormalities in the fish exposed at 30μg/L and 45μg/L concentrations of lindane. ROS and TBARS were found to be significantly increased while CAT, SOD, POD and GSH were significantly decreased with an increase in the concentration and exposure time of lindane. The results showed that lindane causes oxidative stress and severe hematological, serum biochemical and histo-pathological alterations in the fish even at sub-lethal concentrations. [ABSTRACT FROM AUTHOR]

Aquaculture is one of the major economic activities in India, providing livelihoods and nutritional security to millions of people. In recent times, fish diseases have come to the limelight resulting in significant economic losses. We aimed to identify pathogenicity and virulence profiling of thirty-six pathogenic bacterial strains isolated from diseased Labeo rohita in the district of Hooghly, West Bengal, India. The bacterial strains were characterized through a comprehensive approach involving the examination of morphological features, biochemical properties, amplification, and sequencing of the 16S rRNA, species-specific genes, and virulence genes. Considering the prevalence frequency, virulence potential, and statistical significance Aeromonas hydrophila and Pseudomonas aeruginosa were selected for a survival assay followed by the examination of histopathological features to elucidate their effects. The identified bacterial isolates were arranged based on their predominance frequency, i.e., Aeromonas hydrophila (25%), Aeromonas veronii (22%), Pseudomonas aeruginosa (22%), Enterococcus faecalis (14%), Klebsiella pneumoniae (6%), Staphylococcus aureus (6%) and Escherichia coli (5%). Sixteen virulence-associated genes related to pathogenicity were amplified across the thirty-six isolates; aer, alt, lip and hlyA for A. hydrophila; exoS, lasB, toxA, oprL and phzM for P. aeruginosa; entB, fimH and uge in K. pneumoniae; aer in A. veronii; hlyA in E. coli; hlb in S. aureus and gelE for E. faecalis. The log-probit analysis revealed that A. hydrophila was notably more pathogenic than P. aeruginosa, as indicated by its lower lethal dose of 1.5x104 CFU/mL. Additionally, histological examination revealed notable pathological changes, including tissue degeneration, inflammatory cell infiltration and vacuolation observed in the liver, kidney, gill and intestine of the challenged fish. We highlighted several potent aquatic microbial pathogens in order to manage and prevent such aquacultural maladies. [ABSTRACT FROM AUTHOR]

The primary aim of this study was to examine the impact of xylooligosaccharide (XOS) in rice protein concentrate (RPC) based diets on the growth performance, body composition, digestive enzymes, intestinal morphology and blood biochemistry of Labeo rohita fingerlings. Four different XOS levels (0%, 0.5%, 1% and 2%) were used at each RPC (75% and 100%) level. Twenty‐five fish per tank with an average initial weight of 25 ± 0.05 g were randomly assigned (Randomised complete block design) to each of the 8 groups in triplicate aquaria (36 × 16 × 12″) and then fed with respective diets @ 3% body weight for 90 days. The results showed significant improvements in growth performance, such as increased weight gain %, specific growth rate, and protein efficiency ratio and improved feed conversion ratio in 1% XOS supplemented diet at 75% RPC. A significant decrease in serum alkaline phosphatase activity (ALP) and plasma melanodialdehyde (MDA) were observed at 1% XOS level in 75% RPC based diets, respectively. Meanwhile, the lowest total cholesterol and highest lysozyme activity were observed in 1% XOS supplemented diet at 75% RPC levels. Moreover, the serum (alanine aminotransferase and aspartate transaminase) and plasma (superoxide dismutase, triglyceride, high density and low density lipoprotein) activities showed nonsignificant effects among the treatments. Furthermore, the digestive enzymes (protease & lipase) and intestinal morphology were significantly influenced at 1% XOS in the 75% RPC‐based diet. Polynomial regression analysis showed that 1.25% XOS is the optimum requirement for the growth of rohu fingerlings when fed at 75% RPC based diets. Overall, it was concluded that the 75% RPC diet was efficiently replaced by fishmeal along with 1% XOS addition in L. rohita fingerlings without any negative effect on growth performance and intestinal health. [ABSTRACT FROM AUTHOR]

Biochar, an organic carbonaceous matter, is a unique feed additive that is now being used in aquaculture industry to formulate a cost‐effective and eco‐friendly diet. This experiment (in door) was conducted over course of 90 days to determine the most effective form of biochar, produced from various sources, for supplementation in Moringa oleifera seed meal‐based diet. These sources were: farmyard manure biochar, parthenium biochar (PB), vegetable waste biochar, poultry waste biochar (PWB) and corncob waste biochar, added at 2 g/kg concentration to determine the effect of supplementation on the growth indices, nutrient absorption, carcass composition, haematology and mineral status of Labeo rohita (rohu) fingerlings. The research design consisted of six test diets with three replications (6 × 3) of each. Total of 270 fingerlings (6.30 ± 0.020 g) were fed at 5% body weight and 15 of them were kept in separate steel tanks. The results indicated that PWB was most effective in improving weight gain (285.58 ± 4.54%) and feed conversion ratio (1.060 ± 0.040) compared to control diet and other test diets. The same type of biochar (PWB) produced the best results for nutrient digestibility, that is, crude protein, crude fat and gross energy and carcass composition. In terms of haematology and mineral status, PWB showed the best results. In conclusion, it was found that PWB significantly enhanced (p < 0.05) L. rohita fingerling's growth, carcass composition, nutrient digestibility, haematological parameters (red blood cells, white blood cells, platelets and haemoglobin) and mineral composition (Ca, Na, P, Mg, Fe, Mn, Zn, K and Cu) whereas PB negatively affected all parameters. It is anticipated that the potential use of biochar will increase in aquaculture industry, as research on its incorporation in fish feeds is still limited. [ABSTRACT FROM AUTHOR]

Carbofuran pesticide is used to control insects in agriculture and acts as a contaminant that pollutes aquatic ecosystems, exerting harmful effects on fish health. The present study was conducted to evaluate the ameliorative effects of moringa leaf powder after fish being exposed to carbofuran on hematobiochemical and histological changes, oxidative and antioxidative mechanisms in the soft tissues of rohu Labeo rohita. Fish were divided into three groups (A, B, and C). Group A treated as control while groups B and C were exposed to two sublethal doses (0.32 and 0.84 mg/L) of carbofuran for 28 days. At day 28, ten fish were removed from the high dose group and transferred to carbofuran-free freshwater (group D) for recovery responses. Results revealed that concentrations of hemoglobin (HGB), red blood cells (RBCs), high-density lipoprotein (HDL), low-density lipoprotein (LDL), albumin, globulin, total proteins, triiodothyronine (T3), thyroxin (T4) and blood urea nitrogen (BUN) significantly decreased. White blood cells (WBCs), triglycerides, cholesterol, very low-density lipoprotein (VLDL), alanine aminotransferase (ALT), aspartate aminotransferase (AST), blood glucose, thyroid stimulating hormone (TSH), urea, and creatinine levels were elevated significantly in carbofuran exposed fish. Results showed a significant rise in oxidative stress content (TBARS and ROS), and a decline in the activities of antioxidant enzymes such as superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and glutathione (GSH) in the brain, kidney, liver, and gills of exposed fish. Histological alterations showed deleterious effects on different organs in carbofuran-exposed fish. After the recovery period, all parameters were recovered to some extent. The results of this study indicated that carbofuran is harmful to fish even at low doses. Therefore, extreme care should be taken to prevent the drainage of carbofuran into water bodies. [ABSTRACT FROM AUTHOR]

Background: Our investigation focused into Labeo rohita, commonly known as Rui, a freshwater aquatic species in Bangladesh. Despite their nutritional significance, these fish faced a pressing challenge: parasite infections threaten the economic stability of the aquaculture sector. Objectives: The present study aimed to investigate the parasite and histological changes in major organs of L. rohita, collected from Khulna region – Dumuria, Paikgacha and Rupsha. Methods: About 180 (30/month) specimens were collected between the month of March and August 2023 to observe the parasitic status in L. rohita. Results: Through microscopic examination, a total of 323 parasites were uncovered, spanning categories including Cestode, Nematode, Acanthocephala, Trematode and Digenia, predominantly residing in the intestines of L. rohita. The highest prevalence rate (70%) was recorded in both March and May 2023, with peak mean intensity observed in July (3.73). Notably, the highest mean abundance (2.37) exhibited in July and index of infestation (45.34) in June. Histological analysis confirmed parasitic infestations in the gastrointestinal region, with displaying histological changes within major organs such as the liver, kidney, gills, spleen and testicles due to parasitic infection. Conclusion: This study concluded that the indentified six categories of parasite and the affect of parasitic infestation in major organs of L. rohita within the study period. Urgent efforts to implement effective strategies for controlling the parasite infections in aquaculture to ensure the sustainable production of this invaluable fish species. [ABSTRACT FROM AUTHOR]

The study examined the impact of a diet enriched with nanosilver (AgNPs) on the specific immunity, tissue biopsy, and growth effectiveness of Labeo rohita infected with A. carviae. The fish were divided into four groups with replications, and three diets were prepared with AgNPs (0, 10, 15, and 20 µg AgNPs kg-1 diet) added. The fish in the 15µg kg-1 group showed improved growth rates and a 70% survival rate after being challenged with A. carviae. Antioxidant indices, as well as the non-specific immune response, provided notable variations in the inclusion values of AgNPs in the liver and gill. The supplementation of 15µgkg-1 AgNPs most effectively improved tissue damage caused by A. caviae exposure in immunoprotective organs. T3 had higher liver TNF-α transcription than other treatments, while T4 had the highest values for IL-10. The amount of IL-10 in kidneys, gills, and muscles was also higher in T3, T2 and T3 respectively. The research suggests that AgNPs can positively influence fish growth and manage A. caviae infections by boosting antioxidant status and immunity while causing minimal harm to the immunoprotective organs. [ABSTRACT FROM AUTHOR]

This study investigates the reproductive seasonality variation in Indian Major Carps (IMC), specifically Rohu (Labeo rohita) and Catla (Labeo catla). Utilizing field observations and analysis of gonadosomatic index (GSI), distinct reproductive patterns were observed among these species. The findings highlight that, in the absence of scientific interventions such as photoperiod manipulation and feeding management, a significant portion of Rohu and Catla fish reach maturity and breed after and before monsoon period (December and March). Understanding these reproductive variations is crucial for the identification of genetically distinct stocks suitable for line development that can reproduce during the winter seasons. This knowledge contributes to the strategic management of year-round seed availability. By elucidating the natural reproductive cycles of these economically important species, researchers can optimize breeding programs to align with environmental conditions, potentially identifying genetically different stock for line development, which can breed during winter seasons. [ABSTRACT FROM AUTHOR]

A 60-day feeding trial was conducted to determine the effect of papaya leaf meal (Carica papaya) on growth performance and haematology of Labeo rohita fingerlings. Fingerlings were distributed in five different experimental groups with replicates. Each replicate contains 15 fishes with a mean average initial weight of 11.34±0.20g-11.61±0.04g and fed daily twice for 60 days. Five practical iso-nitrogenous diets (~ 30% Protein) were manufactured with graded levels of papaya leaf meal (PLM) with partial replacement of rice bran i.e. T1 (0% PLM), T2 (10% PLM), T3 (15% PLM), T4 (20% PLM) and T5 (25% PLM). A Significant difference (P< 0.05) was observed in growth and nutrient utilization parameters such as weight gain %, specific growth rate (SGR), feed conversion ratio (FCR), protein efficiency ratio (PER). The highest growth was observed in the group fed with diet T4, whereas the lowest was found in diet T1. The haematological studies revealed that the blood parameters such as RBC count, Hb, PCV and MCV were found highest count in the T4 group. The overall results indicated that the fish fed with 20% papaya leaf meal (T4 group) showed the best performance in terms of growth and haematological parameters in this study. Hence, it can be concluded that papaya leaf meal can be included up to 20% in the diet of Labeo rohita (Rohu) fingerlings for optimum production without any deleterious effect. [ABSTRACT FROM AUTHOR]

This study addresses the economic challenges faced by traditional and small fish farmers due to the limited availability and rising costs of conventional fish feed protein sources. The focus is on exploring the potential of non-conventional plant protein sources to reduce the overall cost of fish feed. Specifically, Cassia tora leaf meal is investigated as an alternative protein source for the growth, feed utilization, and survival of Labeo rohita fingerlings. Labeo rohita fingerlings were subjected to experimental diets with varying concentrations of Cassia tora leaf meal, while a control group received only the basal diet as a protein source. The study evaluated key parameters such as FCR, SGR, PER and weight gain. Results indicated that the effect of Cassia tora on the growth and survivability of Labeo rohita is concentration-dependent. While higher inclusion levels led to fluctuations in FCR and PER. The study indicates that incorporating Cassia tora leaf meal, with partial replacement of fish meal, holds promise for enhancing growth, size and weight gain in Rohu fish. [ABSTRACT FROM AUTHOR]

Despite Bangladesh being the world's fifth-largest aquaculture producer, ensuring quality fish supply and food safety is a major challenge. Illegal practices and the presence of harmful microorganisms consistently compromise the integrity of food items throughout the value chain. To address this, a study was conducted in Bangladesh aimed to estimate consumer willingness to pay (WTP) for safer Tilapia, Pangasius, and Rohu fish using an experimental auction method. Results revealed that consumers' average willingness to pay was 29%, 10%, and 21% more for safer Tilapia, Pangasius, and Rohu, respectively, compared to less safe options despite being unaware of specific safety attributes or production practices. After getting information about the aquaculture practices used in fish production, bacterial pathogens, antibiotic levels, and heavy metal content, participants expressed their willingness to pay a higher premium of 52% for safer Tilapia, 39% for safer Pangasius, and 34% for safer Rohu fish. This dynamic illustrates that when consumers possess comprehensive product safety information, their willingness to pay becomes more rational and sensitive to minimize health risks. This WTP is more for safer fish, underscoring the critical role of safety certificates and labeling in meeting the needs of an increasingly health-conscious population. [ABSTRACT FROM AUTHOR]

Market instability, increased competition, escalating price and reduced availability of conventional ingredients warrants the researchers to rely on alternative feed ingredients. This approach may help in producing aqua feeds in a sustainable and cost-effective way to accomplish the global food and nutritional securities. Mahua oil cake (Bassia latifolia) is an underutilized nonconventional ingredient that holds promise for incorporation into aqua feed following nutrient enhancement by solid-state fermentation. A five-month pond feeding trial was carried out to investigate the effects of Sachharomyces cerevisiae and Bacillus subtilis fermented mahua oil cake (MOC) on the production performance, nutrient utilization, digestive capacity, and innate immunological responses of Labeo rohita fingerlings. For this, two isonitrogenous feed were formulated and prepared incorporating fermented MOC at different levels i.e. 0 and 40 percentage replacing soybean meal and other feed ingredients and fed to rohu fingerlings of two treatment groups in pond culture for 5 months duration. Improved growth performance, feed conversion ratio, feed intake, protein efficiency ratio and digestive capacity were observed in fish fed diets with 40 percent of fermented MOC compared to control. Innate immune responses parameters (respiratory burst activity, myeloperoxidase, lysozyme and hemaglutination activities) were significantly higher (P < 0.05) in fishes fed with fermented MOC. Therefore, we conclude incorporation of solid state fermented mahua oil cake up to 40% level in diet of L. rohita fingerlings in pond culture without any adverse effects on growth, nutrient utilization and innate immune response. [ABSTRACT FROM AUTHOR]

Dactylogyrus labei is a dactylogyrid monogenean parasite originally described by Musselius and Gusev (1976) from Labeo rohita (Hamilton, 1822) (Teleostei: Cyprinidae) in two alternative forms: a typical from Lucknow, north India and an atypical from Kalyani, east India. Fresh specimens of D. labei were collected from Mizoram in northeast India, and examined morphologically using high-resolution digital image processing and analysis. The recovered monogeneans most closely resembled the atypical form of D. labei, with only minor differences, indicating conspecificity. The atypical form of D. labei is distinguished from other species of the genus by the following combination of characters: the dorsal bar wing-shaped, with a fine membrane on the anterior margin and a fenestration in the middle; the ventral bar casing nail-shaped with two small antero-lateral processes (3-rayed); the male copulatory tube loosely S-shaped, slender, with an inflated initial part; the accessory piece proximally tubular, distally a complex of multi-layered sheath guiding the copulatory tube, and the vagina tubular, with one small loop and vaginal pore surrounded with a flap-like structure. This study expands the geographical distribution of D. labei while improving its morphological descriptions. [ABSTRACT FROM AUTHOR]

Background: An experimental study was conducted to examine growth performance and economic feasibility of Cyprinus carpio (Linnaeus, 1758) and Labeo rohita (Hamilton, 1822) vis-à-vis their improved strains viz. Amur carp and Jayanti rohu, in synchronously integrated rice-fish system at high altitude terraced paddy-fields (HATPF). Methods: The experimental fields were stocked with carp fingerlings (6.95±0.67 g) at a density of 0.6 no. m-2 having common carp (T1), rohu (T2), Amur carp (T3) and Jayanti rohu (T4) under monoculture system, common carp+rohu (T5) and Amur carp+Jayanti rohu (T6) under polyculture. The study period was 120 days (July to November, 2022). Result: The study recorded average weight gain of 55.72±5.58 g and 57.08±4.05 g in monoculture and polyculture systems, respectively. Amur carp performed significantly better (p<0.05) than other species/strains. Survival rate ranges from 72% to 85% with Amur carp and common carp recorded higher survival than rohu and its strain. Through integration, about 243.2 to 350 kg ha-1 of fish can be produced without supplementary feed and earn about Rs. 60,800 to Rs. 87,500 ha-1 in a single crop. Amur carp and common carp were found more suitable for rearing in integrated rice-fish culture system at HATPF. [ABSTRACT FROM AUTHOR]

A study was conducted in rohu fish, Labeo rohita (Hamilton, 1822) to assess the potential of silkworm pupae, housefly maggot, and earthworm meals as a replacement for soybean meal. In this context, four isonitrogenous and isolipidic diets were prepared, viz., control -- SM (30% soybean meal inclusion level), SPM (30% silkworm pupae meal inclusion), HMM (30% housefly maggot meal inclusion level) and EWM (30% earthworm meal inclusion level). The rohu fingerlings (initial average body weight: 5.07 ± 0.01 g) were fed twice daily with the respective experimental diets to reach satiation levels. Specific growth rate (SGR), final body weight (FBW), per cent weight gain (WG), protein efficiency ratio (PER) and feed conversion ratio (FCR) were significantly affected among the experimental groups. SPM and HMM groups had significantly higher FBW, SGR, WG and PER values than the control - SM and EM groups. However, there was no significant difference between the control and EWM groups, and between SPM and HMM groups. FCR values showed a significant reverse trend in respect to WG. Incorporation of SPM and HMM in rohu diets gave greater growth performance and feed utilisation efficiency than SM and EWM-based diets. [ABSTRACT FROM AUTHOR]

Due to their high content of micronutrients, small indigenous species (SISs) of fish play a vital role in the diets of people. Dhela (Osteobrama cotio) is one of the most important micronutrient‐rich SISs and was once abundant but is currently disappearing from inland waters. This study investigated the culture suitability of dhela with carp species in polycultures in a pond aquaculture system. The stocking density of the carp species was the same in all the treatments, with Labeo catla, Labeo rohita and Cirrhinus cirrhosus at 10,800/ha. Dhela were cultivated at a density of 10,000/ha in treatment 2 (Dhela‐10K) and 15,000/ha in treatment 3 (Dhela‐15K), and no dhela were cultivated in treatment 1 (Dhela‐0). After 7 months of culture, there were no significant differences in total production among the treatments, with yields of 3393.27 ± 120.70, 3534.52 ± 57.03 and 3687.34 ± 244.41 kg/ha in Dhela‐0, Dhela‐10K and Dhela‐15K, respectively. Notably, a significantly greater (p < 0.05) net profit and benefit‒cost ratio were found in Dhela‐10K and Dhela‐15K than in Dhela‐0, but no significant difference was found between Dhela‐10K and Dhela‐15K. The inclusion of dhela in pond polycultures with carp species demonstrates the potential benefits of diversifying aquaculture systems. Farmers could consider incorporating SISs into their existing aquaculture practices to increase overall production and improve economic returns. [ABSTRACT FROM AUTHOR]

Objective: The present research was conducted to evaluate the negative effects of nicotine powder on the blood physiology, and biochemical and histological alterations of Labeo rohita. Materials and Methods: Fish were divided into four groups (1-4). Fish groups 2, 3, and 4 were exposed to different concentrations of nicotine, such as 0.75, 1.25, and 1.75 mg/l, while group 1 acted as a control. To find out the long-term impact of nicotine on body physiology, we conducted a 42-day experiment. After the completion of the experiment, hematology, biochemical assays, and histology were done. Results: Results revealed a considerable increase in HGB, red blood cells, WBCs, hematocrit, mean corpuscular volume, red cell distribution width -SD, procalcitonin, neutrophils, lymphocytes, monocytes, triglycerides, total cholesterol, low-density lipoprotein, very low-density lipoprotein, alanine transaminase, aspartate aminotransferase, globulin, thyroid stimulating hormone, BUN, creatinine, and blood glucose levels, whereas mean corpuscular hemoglobin concentration, mean corpuscular hemoglobin, RDW, platelet, high-density lipoprotein, albumin, total proteins, and T3 levels were significantly (p = 0.05) decreased in exposed fish as compared to control group fish. Histological alterations showed that exposure to smokeless nicotine causes deleterious and degenerative effects in the liver, kidney, and gills of exposed fish. Conclusion: Nicotine administration in fish results in adverse effects on different biochemical and hematological parameters and causes histological alterations in some vital organs of exposed fish. [ABSTRACT FROM AUTHOR]

A 60-day feeding trial was conducted to evaluate the effect of papaya (Carica papaya) leaf meal on the physio-metabolic enzyme response of Labeo rohita fingerlings. Fingerlings were distributed in five different experimental groups with replicates. Each replicate contains 15 fishes with a mean average initial weight of 11.34 ± 0.20 g-11.61 ± 0.04 g and is fed daily twice for 60 days. Five practical iso-nitrogenous fish diets (~30% protein) were prepared with different levels of papaya leaf meal (PLM) with partial replacement of rice bran, that is T1 (0% PLM), T2 (10% PLM), T3 (15% PLM), T4 (20% PLM) and T5 (25% PLM). The digestive enzymes, such as amylase and protease varied significantly. Amylase activity was significantly higher in the T3 group, while protease activity was highest in the T4 group. The activities of metabolic enzymes, such as alanine aminotransferase, aspartate aminotransferase, lactate dehydrogenase and malate dehydrogenases were lowest in the T4 and T5 groups. The oxidative stress enzymes were also recorded for their minimum values in the T5 group. The overall results indicate that the fish fed with 20% PLM (T4 group) showed the best performance in terms of growth and physio-metabolic enzyme parameters, although some of the parameters indicated a better value at 25% inclusion. Hence, it can be concluded that PLM can be included up to 20% in the diet of L. rohita (Rohu) fingerlings for optimum production without any deleterious effect on enzyme activity, which is mostly required for fish growth and production. [ABSTRACT FROM AUTHOR]

ABSTRACT In the aquaculture sector, one of the challenges includes disease outbreaks such as bacterial infections, particularly from Aeromonas hydrophila (Ah), impacting both wild and farmed fish. In this study, we conducted a proteomic analysis of the intestinal tissue in Labeo rohita following Ah infection to elucidate the protein alterations and its implications for immune response. Our findings indicate significant dysregulation in extracellular matrix (ECM)-associated proteins during Ah infection, with increased abundance of elastin and collagen alpha-3(VI). Pathway and enrichment analysis of differentially expressed proteins highlights the involvement of ECM-related pathways, including focal adhesions, integrin cell surface interactions, and actin cytoskeleton organization. Focal adhesions, crucial for connecting intracellular actin bundles to the ECM, play a pivotal role in immune response during infections. Increased abundance of integrin alpha 1, integrin beta 1, and tetraspanin suggests their involvement in the host’s response to Ah infection. Proteins associated with actin cytoskeleton reorganization, such as myosin, tropomyosin, and phosphoglucomutase, exhibit increased abundance, influencing changes in cell behavior. Additionally, upregulated proteins like LTBP1 and fibrillin-2 contribute to TGF-β signaling and focal adhesion, indicating their potential role in immune regulation. The study also identifies elevated levels of laminin, galectin 3, and tenascin-C, which interact with integrins and other ECM components, potentially influencing immune cell migration and function. These proteins, along with decorin and lumican, may act as immunomodulators, coordinating pro- and anti-inflammatory responses. ECM fragments released during pathogen invasion could serve as “danger signals,” initiating pathogen clearance and tissue repair through Toll-like receptor signaling.IMPORTANCEThe study underscores the critical role of the extracellular matrix (ECM) and its associated proteins in the immune response of aquatic organisms during bacterial infections like Aeromonas hydrophila. Understanding the intricate interplay between ECM alterations and immune response pathways provides crucial insights for developing effective disease control strategies in aquaculture. By identifying key proteins and pathways involved in host defense mechanisms, this research lays the groundwork for targeted interventions to mitigate the impact of bacterial infections on fish health and aquaculture production.

The objective of the current study was to assess the impact of dietary phytase supplementation on Labeo rohita fingerlings and to examine the effects on growth, nutrient digestibility and chemical characteristics of diets containing rice protein concentrate (RPC) as a major protein source. Six experimental diets were made, i.e., a positive control (fishmeal-based diet with no phytase), FM0; a negative control (RPC-based diet with no phytase), RPC0; and four supplemental phytase levels (250, 500, 1000, and 2000 FTU/kg). Fingerlings with an average weight of 9.42 ± 0.02 grams (mean ± SD) were randomly distributed into six experimental groups of three replicates, each containing 25 fish per tank (75 liters of water), provided with experimental diets at a rate equivalent to 5% of their body weight for 90 days, and uneaten feed was collected after 2 hours to determine feed consumption. The feces were collected before feeding to estimate digestibility. Phytase in combination with the RPC-based diet significantly (p < 0.05) enhanced phytate phosphorus in vitro hydrolysis; growth performance; nutrient (crude protein, crude fat, moisture and gross energy) and mineral (P, Ca, Mg, Na, K, Zn, Mn and Cu) digestibility; digestive enzyme (protease, lipase and amylase) activity; and mineral deposition up to 1000 FTU/kg phytase. However, the hepatosomatic and viscerosomatic indices and carcass composition were not influenced (p > 0.05) by phytase supplementation. Increasing phytase supplementation in the RPC-based diets led to a significant (p < 0.05) decrease in the serum biochemical parameters (alkaline phosphatase activity, aspartate aminotransferase, alanine aminotransferase), which resulted in improved liver health. In conclusion, phytase-supplemented RPC-based diets improved the growth, mineral/nutrient digestibility, digestive enzymes, serum biochemistry, and mineral deposition of L. rohita fingerlings up to 1000 FTU/kg. Broken line regression analysis revealed that the optimum phytase concentration in the RPC-based diet for L. rohita was 874.19 FTU/kg. [ABSTRACT FROM AUTHOR]

A 171-day long experimental trial was undertaken to study intricate physiological response of rohu (Labeo rohita) under stress caused by high stocking density in In-pond raceways system (IPRS). Fingerlings of rohu (initial body weight: 250 ± 1.20 g) were cultured at three different stocking densities; low density (LD) (2.27 kg/m3), medium density (MD) (3.79 kg/m3) and high density (HD) (5.30 kg/m3) in raceways of IPRS production system. Each treatment was in triplicate. Fish growth exhibited a decline in HD treatment statistically as its average weight gain/fish/day was 4.21 g as compared to MD (4.82 g) and LD (4.74 g). Nutritional profile of rohu indicated by the content of crude protein, fatty acids, and profile of amino acids was up to the set dietary benchmarks. Survival rate of fish in all the treatment groups was greater than 99%. The elevated cortisol levels observed in the HD treatment in contrast to the other treatments suggested the presence of stress. The levels of superoxide dismutase, catalase and glutathione peroxidase were also higher in HD as compared to other treatments. However, there were no difference in the level of MDA between the three treatments. Activity of amylase, protease was significantly different in treatment whereas the difference in lipase activity was found to be insignificant. It can be concluded that medium stocking density i.e. 3.79 kg/m3 outperformed the high density (5.30 kg/m3) in different aspects of this study. Nevertheless, additional research is imperative to ascertain whether any intermediate stocking density between medium (3.79 kg/m3) and high (5.30 kg/m3) such as 4 kg/m3, 4.5 kg/m3, or 5 kg/m3, could potentially serve as suitable options for rohu. It is also suggested that brood stock of rohu should be genetically improved to obtain stress resilient fingerlings which will perform better at high stocking density at large scale production level. [ABSTRACT FROM AUTHOR]

The present study explores the use of periphyton to ameliorate toxic properties of arsenic (As) to Labeo rohita and also assesses the human food safety aspects. Fish were introduced to arsenite [As(III)] contaminated water (0.3 and 3 mg/L) along with periphyton. Biochemical, physiological and immunological parameters, including gene expression, were assessed after 30 days of exposure. Periphyton incorporation significantly improved (p < 0.05) the adverse effects of As on respiration, NH3 excretion and brain AChE activity by reducing oxidative stress and As bioaccumulation. The presence of periphyton in As(III) exposed fish (3 mg/L) increased the immune response (Immunoglobulin M and Complement C3) in the serum and the regulation of the respective immune genes in the anterior kidney was found to be similar to the control. A speciation study using LC-ICP-MS confirmed the high accumulation of As by periphyton (5.0–31.9 μg/g) as arsenate [As (V)], resulting in a lower amount of As in fish muscle. The calculated human health risk indices, Target Hazard Quotient (THQ) and Target Cancer risk (TCR) indicate that fish grown in periphyton-treated water may lower the human health risks associated with As. The study signifies the importance of periphyton-based aquaculture systems in As contaminated regions for safe fish production with enhanced yield. [ABSTRACT FROM AUTHOR]

Parabens are being used as preservatives due to their antifungal and antimicrobial effects. They are emerging as aquatic pollutants due to their excessive use in many products. The purpose of this study was to determine the toxic effect of ethyl paraben (C9H10O3) on the hematobiochemical, histological, oxidative, and anti-oxidant enzymatic and non-enzymatic activity; the study also evaluates the potential of ethyl paraben to cause genotoxicity in Rohu Labeo rohita. A number of 15 fish with an average weight of 35.45±1.34g were placed in each group and exposed to ethyl paraben for 21 days. Three different concentrations of ethyl paraben, i.e., T1 (2000μg/L), T2 (4000 μg/L), andT3 (6000 μg/L) on which fish were exposed as compared to the control T0 (0.00 μg/L). Blood was used for hematobiochemical and comet assay. Gills, kidneys, and liver were removed for histological alterations. The results showed a significant rise in all hemato-biochemical parameters such as RBCs, WBCs, PLT count, blood sugar, albumin, globulin, and cholesterol. An increase in aspartate aminotransferase (AST) and alanine transaminase (ALT) levels directed the hepatocytic damage. Histological alterations in the liver, gills and kidneys of fish were found. Ethylparaben induces oxidative stress by suppressing antioxidant enzyme activity such as SOD, GSH, CAT and POD. Based on the comet assay, DNA damage was also observed in blood cells, resulting in genotoxicity. Findings from the present study indicate that ethyl paraben induces hemato-biochemical alterations, tissue damage, oxidative stress, and genotoxicity. [ABSTRACT FROM AUTHOR]

Reliance on fish meal can be reduced by incorporating plant-based ingredients, making aquaculture more economical, sustainable and environmental friendly. In this study, the efficacy of plant protein ingredients (PPI) such as mustard oil cake (MOC), soybean meal (SBM) and rice bran (RB) as Partial substitute of fishmeal (FM) was investigated for a commercially important fish, Labeo rohita in cages for 90 days. Three experimental diets, labeled as Diet 1, Diet 2, and Diet 3, were formulated to be isonitrogenous (with protein content ranging from 32.20 to 32.29%) and iso-caloric (with gross energy ranging from 4.12 to 4.17 kcal/g). These diets contained different proportions of PPI (45, 68, and 79%) and FM (46, 23, and 11%, respectively). Square-shaped cages with a volume of 1m3 (1 m × 1 m × 1 m) were stocked with 40 fish/m3 each with an average initial weight of 52.97 g in triplicates. Fish were hand-fed to apparent satiation twice daily for 7 days a week at a feeding rate of 5% in the initial month and 3% for the rest of the culture period. 50% of the caged fish was sampled monthly to monitor growth performance and at the termination of the experiment, all the fish was harvested to measure production economics performance. The results indicated improved growth performance and higher feed utilization at Diet 2, yielding significantly (p < 0.05) higher fish production compared to Diet 3, while these parameters were insignificant with Diet 1. By replacing FM with PPI, the total feed cost compared to Diet 1 was reduced to 20.62 and 32.76% for Diet 2 and Diet 3, respectively. The replacement of 50% FM in Diet 2 also yielded a 15.61% higher total economic net return than the Diet 1 group. However, a higher inclusion rate of PPI in Diet 3 potentially reduced fish growth, with a consequent decline of 41.61% total economic net return compared to the Diet 1 group. In conclusion, the replacement of 50% FM in Diet 2 compared to Diet 1 returned a higher benefit-cost ratio (1.72) among the feeding groups. Therefore, this FM replacement experiment suggested a 50% FM replaced diet as an unconventional, cost-effective, and readily available novel protein source without compromising the inherent nutritional quality of fish and feed in the cage culture of L. rohita. The results could be widely applicable to the fastgrowing approach of cage culture technology across Asia and beyond. [ABSTRACT FROM AUTHOR]

The major carp Rohu (Labeo rohita) is a prime freshwater aquaculture species across the Indian subcontinent that faces various production‐related issues associated with water quality parameters. The present study examined the effects of three different doses of NH3 (T1 = 1 mg/L, T2 = 2 mg/L and T3 = 3 mg/L) on cellular (gill ultrastructure), physiological (growth and oxygen consumption rate), biochemical (blood cell counts, blood cortisol and glucose levels) and genetic (expression of five genes involved in growth, immunity and metabolism) traits of Rohu. The experimental ammonia dose significantly affected the tested biological parameters (p < 0.05), causing moderate‐to‐severe gill tissue damage. In general, compared with those in the control group, 16%–25% slower growth, 12%–30% lower survival and 15%–56% higher O2 consumption were observed for the treatment groups. Blood glucose and cortisol levels increased with increasing ammonia levels, but blood cell counts decreased. The five selected candidate genes showed a differential expression pattern in response to the ammonia dose, with higher expression in the control group and lower expression in the treatment groups. The results indicate that different concentrations of ammonia impose stress on different orders of magnitude in the experimental fishes. Therefore, it can be inferred that the presence of ammonia in aquatic/farming environments can adversely affect production performance; the severity of damage during production depends on the concentration of ammonia. Therefore, maintaining no or minimum ammonia levels in farming environments is urgently needed for sustainable aquaculture production of Rohu. [ABSTRACT FROM AUTHOR]