Antiparasitic efficacy and safety evaluation of green-synthesized silver nanoparticles as sustainable nanotherapeutics against Argulus siamensis in Labeo rohita.

Propylparaben, a frequently used preservative in cosmetics, medicines, and food items, has gained attention due to its extensive prevalence and possible ecological consequences. This research has been conducted to assess the impacts of propylparaben on hematobiochemical parameters, histopathology, oxidative stress, antioxidant enzyme activity, genotoxicity and apoptosis regulatory gene expression in Labeo rohita. Fish were exposed to three concentrations (3mg/L, 6mg/L, and 10mg/L) of propyl paraben for 21 days. Results revealed significant alterations in hematobiochemical parameters. Alterations were observed in the soft tissues of fish, for example, the liver, kidneys, and gills. The gills exhibit lamellar lifting damaged epithelial tissues, deformities in bone cells, and oedema. The liver displayed elongated tubules, sinusoidal spaces, and melano-macrophages, while the kidney displayed sinusoidal spaces, necrosis, and pyknotic nuclei. Propyl paraben causes oxidative stress by inhibiting the activity of enzymes that function as antioxidants, including superoxide dismutase (SOD), glutathione reductase (GR), catalase (CAT) and Peroxidase (POD). Comet assay reported DNA damage in red blood cells (RBCs) of fish. Gene expression study indicated decreased expression of the anti-apoptotic gene Bcl-2 and increased expression of the pro-apoptotic gene Bax, indicating that apoptosis in tissues causes cell death. These results indicated that propyl paraben is potentially genotoxic, causes tissue damage, alters biochemical parameters, induces oxidative stress and regulate apoptosis gene expression.

Biofloc technology (BFT) has emerged as a sustainable and nutrient-efficient approach to aquaculture, providing a practical response to resource limitations in Bangladesh's fisheries sector. This study examines the present condition, key challenges, and prospects of biofloc fish farming in Rajbari Sadar Upazila, Rajbari. Primary data were gathered from six selected farms using structured questionnaires and focus group discussions. The results show that the farms cultured a variety of fish species, including Labeo rohita, Catla catla, Cirrhinus mrigala, and Hypophthalmichthys molitrix. The overall stocking density recorded across the farms was 3,150 fish per acre. Demographic findings reveal that 95.83% of the farmers were male, while the largest proportion (33.33%) belonged to the 31–40 age group. In economic terms, production costs ranged from 253,200 to 358,150 BDT, with feed and fish fry accounting for the highest expenditures. Despite the considerable input costs, biofloc farming proved to be profitable, with the highest net profit reaching 129,975 BDT. Nevertheless, the sector continues to face significant constraints, including frequent disease outbreaks mainly fungal (40%) and bacterial (34%) along with high production costs and insufficient technical knowledge among farmers. While biofloc farming shows high potential, its future success in Rajbari depends on improved technical training, access to quality resources, and enhanced financial support.

The Pearl River Estuary (PRE) is highly vulnerable to alien species invasion due to intense anthropogenic activities in southern China. However, the invasion risk of alien aquatic vertebrates in the PRE remains unclear. In this study, 12 environmental DNA (eDNA) samples were collected from the PRE to reveal the composition and distribution of alien aquatic vertebrates using a vertebrate-universal primer set, and to assess their invasion risks using the Aquatic Species Invasiveness Screening Kit (AS-ISK). We identified a total of nine alien aquatic vertebrate species, including one amphibian (Aquarana catesbeiana) and eight fish species (Coptodon zillii, Oreochromis niloticus, Gambusia affinis, Cirrhinus mrigala, Labeo rohita, Pterygoplichthys pardalis, Ictalurus punctatus, and Neosalanx taihuensis). Notably, six of the nine alien species were detected at eight or more sampling sites, indicating their wide distribution in the PRE. Moreover, all nine alien species were classified as high risk based on AS-ISK, suggesting potential damage to local ecosystems and the aquaculture industry. Our study can help inform policy decisions for the prevention and control of alien aquatic vertebrates in the PRE.

Fish is an important food source containing high quality proteins, vitamins and minerals. The spoilage of fish meat causes a huge economic loss at local and commercial level that can be minimized with efficient preservation. The demand of natural organic preservatives is increasing in recent years due to the hazardous effects of synthetic preservatives. Among the natural preservatives, essential oils in combination with chitosan have been proved a good edible meat preservative candidate. Consequently, we carried out our work to evaluate the preservative effect of garlic oil and chitosan, both solo and in combination, on refrigerated Rohu (Labeo rohita) meat by following two-factor factorial completely random design (CRD) experimental design. Garlic oil (0 & 1%) and chitosan (0 & 1%) in 2 × 2 interaction was applied on refrigerated fillets of Rohu meat. The methodology involved weekly evaluation of proximate composition, analyses of protein and fats degradation, and investigation of sensory and microbial attributes over a three-weeks preservation period. Results indicated that application of 1% garlic oil in combination with 1% chitosan improved preservation and shelf life of Rohu meat, sufficiently safe for human consumption, up to 14 days without exceeding safety limits of all parameters studied. Therefore, it is suggested that the combination of garlic oil and chitosan may be used as an alternate preservative in refrigerated conditions for Rohu fillets preservation and shelf life extension.

Biochemical Study of Freshwater Fish Labeo rohita Infected with Helminthes Parasites from Nashik District, Maharashtra

Myxozoans have been classified into 62 genera having more than 2600 species all over the world. Among these genus Thelohanellus Kudo, 1933 is the second largest genus after Myxobolus. During the survey of myxozoan parasites in fresh water fishes, the species Thelohanellus bifurcata Basu and Haldar, (1999) under genus Thelohanellus Kudo, 1933 was found to infect the gills of Indian major carp, Labeo rohita Hamilton, 1822 collected from Ranaghat fish markets (Latitude: 23.1793º N, Longitude: 88.5758º E), West Benagl, India. A total number of 67 fish were collected during the period of January, 2025 to October, 2025 and among them 6 fishes were found to be infected with the parasite. The rate of infection was 8.95%. The plasmodia were visible with naked eye and were large and elongated in shape. The present paper deals with the morphological re-description and molecular characterization of the parasite. The phylogenetic analysis was also done using the 18s rRNA gene sequences which justifies its taxonomic position and resolves the ambiguities regarding the species identification. This study also presents the molecular analysis of Thelohanellus bifurcata Basu and Haldar, (1999) for the second time from Indian sub-continent and for the first time from West Bengal.

Freshwater ecosystems are important in sustaining biodiversity and livelihoods, especially in semi-arid areas like Marathwada. Godavari River, the surrounding ponds, and reservoirs of Chhatrapati Sambhajinagar create a great habitat for fish species. The research purpose of the current study is to determine the taxonomic diversity, species composition, and distribution of freshwater fishes in these water bodies. The research design was to perform field sampling and secondary data analysis to record fish species and taxonomically classify them. The findings showed a diverse ichthyofaunal biomass comprising families like Cyprinidae, Bagridae, and Channidae. The fisheries of the area are mainly Labeo rohita, Catla catla, Cirrhinus mrigala, and catfish. According to previous research in the Godavari basin, there were almost 60 fish species, meaning that the area is very biodiverse. Nevertheless, the research also determines the major risks associated with anthropogenic processes that include pollution, the construction of dams, and overfishing, which negatively affect the fish diversity and distribution. Finally, the paper provides an emphasis on the environmental significance of freshwater ecological systems and the necessity of immediate conservation and sustainable management practices. The conservation of the fish diversity is important to provide ecological balance, improve the fisheries productivity, and secure long-term food security in the region.

Synthetic detergents including Linear alkylbenzene sulfonates (LAS) and Branched alkylbenzene sulfonates (BAS) are commonly used in household and industrial cleaning products, yet their chronic toxicological effects on freshwater fish species remain inadequately explored. The current study investigates the sub-lethal effects of these synthetic detergents on hemato-biochemical profile of freshwater fish Labeo rohita. The 96-h LC50 values of LAS and BAS for the selected fish were calculated as 6.45mg/L and 8.31mg/L, respectively, using the probit analysis method. A total of 180 fish specimens were randomly subjected to a triplicate experimental setup, with 60 fish allocated to each replicate, marked as G0, G1, G2 ang G3 where G0 served as control while the remaining three groups were treated with LAS (3.22mg/L), BAS (4.15mg/L) and their binary mixture (LAS, 1.61mg/L + BAS, 2.7mg/L) respectively, for a period of 30days. Post exposure analysis revealed a significant reduction (p < 0.05) in the RBCs, hemoglobin, and hematocrit value with increase in WBCs and platelets count in detergents exposed fish, compared to control. Among endocrine hormones T3, T4 and insulin levels decreased significantly (p < 0.05), while TSH and Cortisol were increased in the detergents exposed fish. Blood levels of NO, IgM, and RB were significantly decreased (p < 0.05) in all detergent treated fish, whereas lysozyme activity was significantly increased only in the LAS and mixture detergent treated fish. Antioxidant biomarkers, including CAT, SOD, and GSH, were significantly decreased (p < 0.05), whereas MDA levels showed a marked increase in detergents exposed fish. Histopathological analysis identified substantial alterations in gill tissues across all the detergents exposed groups. Furthermore, genotoxic analysis demonstrated a significant (p < 0.05) increase in micronuclei (MNs) and erythrocytic nuclear abnormalities (ENAs), confirming the genotoxic potential of the tested detergents. These findings suggest that chronic exposure to commonly used detergents can disrupt multiple physiological systems in L. rohita, highlighting the potential ecological risks of detergent pollution in freshwater ecosystems.

Nano-encapsulated fermented feed enhances growth, physiology, and immune responses in Labeo rohita larvae: A sustainable alternative to live feed for early rearing

Epigenotoxicity of Bisphenol A altered global and ten-eleven translocation-dependent DNA methylation in a non-model fish.

Phytochemical Analysis and Efficacy Determination of Sargassum cristaefolium Extract Against Aeromonas hydrophila Infection in Labeo rohita Through In Vivo and In Vitro.

Nonspecific cytotoxic cell receptor protein type I (NCCRP1), as an important type of receptor protein, plays a key role in the immune process of teleost, which triggers cytotoxic reactions by recognizing and binding to multiple target cells. In this study, the NCCRP1 gene sequence of Megalobrama amblycephala was cloned by PCR technology. Its length was 726 bp and the open reading frame (ORF) was 702 bp, which encoded 233 amino acids, with a relative molecular weight of 26.87 kD. Through homologous sequence retrieval in NCBI, the amino acid sequence of Megalobrama amblycephala NCCRP1 was compared with other fish NCCRP1, and the similarity was as follows: Labeo rohita (87.12%), Carassius auratus (85.84%), Danio rerio (83.26%) and Cyprinus carpio (82.05%). The genetic phylogenetic tree was constructed using the adjacency method. The NCCRP1 gene of Megalobrama amblycephala was clustered into one branch with that of Cyprinidae fish. Megalobrama amblycephala NCCRP1 had the closest genetic relationship with that of Ctenopharyngodon idellus . The NCCRP1 expression in different tissues was detected by qPCR. It was found that the expression level of the NCCRP1 gene was highest in the head kidney, followed by the spleen, liver and posterior kidney. After infection with Aeromonas hydrophila , the expression level of NCCRP1 gene in head kidney, spleen, gill and intestine first increased and then decreased during 21 days. The NCCRP1 expression was reached the peak at 5d in head kidney, spleen and gill, and reached its maximum at 7 d in intestine after infection, which indicated that the NCCRP1 expression could be significantly induced after infection with Aeromonas hydrophila . The maximum relative expression of NCCRP1 gene in head kidney and spleen were 19.84 folds and 7.82 folds, respectively, which were significantly higher than those in intestine (5.32 folds) and gill (6.35 folds). It indicated that Megalobrama amblycephala NCCRP1 might play an important role in the systemic immune tissues of the head kidney and spleen in the process of resisting Aeromonas hydrophila infection.

Fish is an indispensable source of food security. Indian Major carps (IMC) are contributing a major share in the fish farming industry and food markets. Evaluation of the impact of dominant fish species on cultivable fish species in open water ecosystems has been a necessary concern. Artificial stockings are necessary to increase the productivity and abundance of cultivable fish species in aquaculture. The present study was conducted from 2017 to 2021 for five years to assess the survival percentages of IMCs in Srirangapur Balancing Reservoir located in Wanaparthy district of Telangana State in India. The results indicated less than 5% of seed survival against a huge seed stocking of three species of IMC VIZ., Catla catla (Katla), Labeo rohita (Rohu) and Cirrhinus mrigala (Mrigala), suggesting that the survival percentage of these cultivable fish species was seriously affected in this reservoir by Tilapia (Oreochromis niloticus) which was dominating with 3-fold abundance than that of the stocked cultivable fish during the five-year study period.

Dried fish is a widely consumed food product and is highly susceptible to fungal contamination during drying, storage, and marketing. The present study investigated the seasonal diversity and distribution of fungi associated with dried Labeo rohita marketed in Jammu, Union Territory of Jammu and Kashmir, India, over a one-year period (January–December). A total of 28 fungal species belonging to 12 genera were isolated and identified. Aspergillus, Penicillium, Fusarium, Cladosporium, Mucor, and Rhizopus were the dominant genera. Several species, including Aspergillus flavus, A. fumigatus, A. niger, A. terreus, Penicillium chrysogenum, P. expansum, and Fusarium moniliforme, were detected throughout the year, indicating strong ecological adaptability. Pronounced seasonal variation in fungal diversity and abundance was observed, with the highest fungal load during summer and monsoon months and a marked decline during winter. Many of the dominant fungi are known producers of mycotoxins such as aflatoxins, ochratoxin A, fumonisins, and trichothecenes, indicating a potential food safety risk. These findings emphasize the influence of climatic conditions on fungal contamination and highlight the need for improved drying, storage, and routine monitoring to ensure the safety and quality of dried L. rohita.

Labeo rohita, also known as rohu, is an important type of fish found in India. It has become a major part of the fish population in the Gandhi Sagar Reservoir (GSR) because it was intentionally introduced as part of a planned stocking program. This man-made lake is located in Madhya Pradesh, on the Chambal River. Originally, the lake had only native fish species, but now rohu and Catla catla make up a large part of the fish caught there.Growth and Development: L. rohita in the reservoir grows steadily and consistently because the water environment is good and there is not too much competition for food and space. In ideal farming conditions, this fish can grow to 500–1,000 grams in one year. In natural river systems, the fastest growth happens in the first year, such as 34.6 cm in one study, and then slows down as the fish gets older. The species usually starts breeding in its second year. The relationship between the length and weight of L. rohita in similar environments often shows that weight increases a little slower than the cube of its length, called negative allometric growth. However, some studies in other areas have found that the growth is proportional, called isometric growth. Lifespan: Studies on L. Rohita in river systems have found that some fish can live up to 11 years. One study recorded a fish of this age. The maximum age generally recorded is close to 10 years. Gandhisagar Dam is located at 22°04′N and 75°22′E, on the border between Madhya Pradesh and Rajasthan. The reservoir spans an area of 660 km². When the dam is full, the water level is 399.9 meters, with an average area of 402 km². The maximum length of the reservoir is 67.8 km, and the maximum width is 26.1 km. Construction of the dam started in 1954 and was completed in 1960. Over 228 villages were either completely or partially submerged due to the flooding caused by the dam. Full submergence happens when the water level reaches around 50 meters, but due to low rainfall in the last three years, the dam's capacity utilization has dropped by more than 40%. During the study period in December to January 2001–2002, the water level was 381.9 meters, which reduced the area of submergence by about 250 km². Many large islands became visible again in the reservoir, and the state government allocated large areas on both banks for farming. Conservation Methods: Managing L. rohita in the Gandhi Sagar Reservoir involves several strategies to make sure the fish population stays healthy and the fishery is sustainable. Stocking Support: Keeping up with stocking young fish and fingerlings is an important management activity, especially as the reservoir environment may affect natural reproduction. RegulatoryMeasures: Laws are important for managing the fishery. These include setting closed season when fishing is not allowed, creating protected areas, and controlling fishing nets to keep them from catching baby fish. Habitat Management: The physical features of the reservoir, such as shallow areas, pools, and gorges, offer necessary feeding and sheltering spots for the fish. Cooperative Management: Working with and organizing local fishermen into cooperatives helps manage fishing Because of improvements in multiple spawning of carps, there is a growing need for high-quality larval diets. Larval fish lack the right enzymes or enough digestive enzymes to process feed efficiently. This means that breaking down feed ingredients into simpler nutrients using bacterial enzymes may help these young fish. Five experimental diets (D1–D5), each with the same calorie and protein content, were made with 32% fish meal, 34% mustard oil cake, 30% rice bran, and 2% cod liver oil. These diets were fermented in a lab using Bacillus circulans bacteria (at a rate of 108 cells per gram) at 37°C for 1 to 5 days. The bacteria used came from the intestines of young rohu fish (Labeo rohita). A non-fermented diet (RD) was also tested. Rohu eggs (average weight 0.35 mg) were given these diets freely for 21 days, feeding them every half hour from 9 a.m. to 4 p.m. Results fermenting the diets increased the amount of protein and free amino acids, while reducing crude fiber. Diets fermented for 4 and 5 days (D4 and D5) led to the best growth and survival (98% and 98.33%) of rohu eggs compared to other diets. A strong positive link was found between the RNA:DNA ratio and specific growth rate across 18 dietary groups (6 groups tested in triplicate).

Tissue-Specific Arsenic Bioaccumulation in Labeo Rohita and Catla Catla Across Contaminated Districts of West Bengal, India.

Cinnamon has emerged as a promising herbal supplement, revealing its potential in alleviating the harmful impacts of aquatic pollutants on various fish species. This study was conducted to investigate the protective potential of cinnamon (Cinnamomum zeylanicum) powder (CzP) in reducing waterborne-induced lead (Pb) toxicity in Labeo rohita. The research trial included six groups: a control group, a Pb-exposed group without CzP supplementation, and four Pb-exposed groups with CzP supplementation at dietary inclusion levels of 5, 10, 15, and 20g/kg in triplicates. Fish were fed at 5% of body weight for 60days. Upon completion of the experimental phase, several parameters were examined including growth performance, proximate body composition, intestinal enzyme activity, Pb accumulation in tissues, and hematological indices. The results demonstrated that waterborne Pb exposure negatively impacted all evaluated parameters. However, incorporating CzP into the diet notably improved physiological traits. The group supplemented with 10g/kg CzP exhibited significant improvements in growth, proximate composition, digestive enzyme activity, reduction in Pb accumulation, and blood profile of fish. In conclusion, our research demonstrates that dietary inclusion of CzP (especially at the level of 10g/kg) can significantly counteract Pb toxicity and enhance growth performance and health status of L. rohita.

The motive of the investigation was to assess the effect on nutritional value of Labeo rohita fish after 96 hours exposure to acute concentrations of spinetoram insecticide, i.e., 2 ml and 4.5 ml. The nutritional parameters study showed moisture, carbohydrate, energy, crude protein, crude fibre, crude fat and total minerals levels declined significantly from day 1 to day 4. This research shows a major depletion in the nutritional value of fish, which combined with the fact that fishes are exposed to spinetoram under natural conditions.

Understanding how large river networks shape genetic variation is critical for conserving freshwater biodiversity in the regions under ecological and socio-economic pressures. In South Asia, the rohu carp Labeo rohita is one of the most popular freshwater fish. Yet, the diversity of its population structure across rivers of different countries remains poorly understood. Here, we integrate mitochondrial cytb sequences of L. rohita originating from Bangladeshi rivers with those from Indian rivers to assess genetic diversity, spatial structure, and divergence across eight rivers. Analyses of 308 individuals revealed two divergent genetic clusters: one comprising eastern rivers (Ganga, Padma, Jamuna, Halda) and the other including western and northern rivers (Satluj, Rapti, Mahanadi, Brahmaputra). Despite its location in India, the Ganga population clustered with Bangladeshi rivers, consistent with historical hydrological connectivity, while the Satluj population showed the highest genetic divergence, likely reflecting long-term isolation in the Indus basin. The Ganga population also exhibited notably low haplotype and nucleotide diversity, suggesting genetic erosion due to decades of unregulated hatchery stocking. Bayesian clustering, AMOVA, and pairwise FST analyses confirmed strong spatial structuring (FST = 0.203, p < 0.001), and isolation-by-distance patterns indicated a relationship between distance and gene flow. A median-joining haplotype network revealed a star-like topology, suggestive of recent demographic expansion. Phylogenetic reconstruction supported recognition of eastern and western lineages as distinct management units. These findings highlight the need for basin-specific broodstock management, genetic monitoring, and international conservation strategies to sustain genetic diversity in this economically important freshwater species.