•Cr(VI) causes behavioural, histological, immunological changes in fresh water fishes.•Cr(VI) induces formation of micronuclei, binucleated cell and DNA breakage in fish RBC.•It also induces ...endocrine disruption in fish altering action of T3, T4, TSH and cortisol etc.•Chronic exposure of Cr(VI) results in hyperglycemia and hyperlactamia in fishes.•Enzymological activity has been found to be altered due to chronic exposure of Cr(VI).
Chromium is considered as one of the most common ubiquitous pollutants in the aquatic environment, but the pure metallic form is absent naturally. There are three oxidation states in case of Chromium viz., Cr (II), Cr (III), Cr (VI). Among which Cr (II) is most unstable. Cr (III) and Cr (VI) are the stable oxidation state of Chromium in the environment. Being one of the commonly used metals Chromium and its particulates enter the aquatic medium through effluents discharged from different industries like textiles, tanneries, electroplating workshops, ore mining, dyeing, printing-photographic and medical industries. Among these, hexavalent chromium is considered as the most toxic form because it readily passes cellular membranes and then reduced to trivalent form. This trivalent chromium combines with several macromolecules including genetic material inside the cytosol, and is ultimately exposes the toxic and mutagenic alterations due of chromium toxicity. Chromium is taken up either through gastrointestinal tract or respiratory tract. The amount varies depending upon the medium and the form of chromium. In this review, an attempt has been made to accumulate the mammoth available data regarding impact of chromium on fresh water fishes into a systematic representation. The main objective of the review is to provide a future guideline for the scientific community and public officials involved in health risk assessment and management ensuring a better environmental condition for human health.
The present study is aimed to investigate the effect of biofloc intake on Genetically Improved Farmed Tilapia (GIFT), developed within the system and its influence as feed supplementation on water ...quality, growth performance, immunological parameters, antioxidant status, immune gene expression, and its resistance to Aeromonas hydrophila infection. GIFT Tilapia juveniles of 5.1 g (±0.05) were stocked at a density of 15/m3 in lined ponds of 300 m2 in triplicates for 180 days. The experimental groups consisted of T1-biofloc developed within the culture systems (insitu), T2-biofloc supplementation in fish feed (exsitu) and C- Control without biofloc. Distillery Spent wash was used as a carbon source to maintain the C/N ratio of 10:1 for floc development in T1. Free CO2, pH, BOD, dissolved oxygen, alkalinity, Calcium and Magnesium ions, Nitrate, Nitrite and ammonia were found to be significantly different between the treatments and control throughout the experiment. The immunological (Serum protein, Respiratory burst test (RBT) and Myeloperoxidase) and antioxidant indicators (Glucose, Superoxide dismutase (SOD) and catalase) were found to be significantly higher in T1 at the end of the trial. Increased weight gain, specific growth rate, survival and decreased feed conversion ratio was found in T1 when compared with the other experimental groups. Real time quantitative PCR analysis revealed that there was no folded expression of the immunological genes such as Metallothionein gene, cathepsin L, Toll like receptor 7, Interleukin 1 β and Tumour necrosis factor α in liver and intestine for both control and treatment. However, the upregulated expression of targeted genes except tumour necrosis factor α was found in head kidney of T1. At the end of the study, GIFT Tilapia when infected with Aeromonas hydrophila showed an improved immune response in T1 and T2 with lesser signs of infection than Control. The findings of the present study affirmed the importance of biofloc technology in triggering the immunomodulatory response of GIFT Tilapia with its upregulated immune gene expression and its role as an antimicrobial agent against Aeromonas hydrophila. This study suggests the adoption of in-situ (T1) based biofloc method to obtain better performance of GIFT Tilapia culture.
•Biofloc Supplementation in the diet and its intake from the culture system was compared for the first time in GIFT Tilapia.•Insitu reared animals showed upregulated Immune gene expression with respect to disease resistance against A. hydrophila.•Biofloc developed in insitu method showed improved growth and immune performance in GIFT Tilapia compared to exsitu culture.
This study aims to evaluate the influence of different carbohydrate sources on water quality, growth performance and immunomodulation in pacific white shrimp and to find an alternate for molasses in ...biofloc system. The experiment consists of 8 biofloc treatments with different carbon sources, C1 (maida flour), C2 (wheat flour), C3 (gram flour), C4 (millet flour), C5 (rice flour), C6 (corn flour), C7 (molasses), C8 (multigrain flour) and un-supplemented control C0 was conducted in 200 L tank system for 120 days. Shrimp juveniles of average weight 1 g were stocked at the rate of 300 nos/m3. Shrimp reared in C8, C7 and C4 treatments had similar growth, survival rate, and disease resistance and were significantly higher (P < 0.05) than other treatments including control. Immune parameters like total hemocyte count (THC) and prophenoloxidase (ProPO) activity showed significantly higher (P < 0.05) levels in biofloc treatment groups. The genes targeting the proPO cascade (PX, BGBP) and antioxidant defense systems (SOD, MnSOD, CAT) revealed significant upregulation in the transcript levels indicating an enhancement in the immune-regulatory functions in the BFT groups. The results suggest that millets and multigrain flour can effectively replace molasses as the carbohydrate source for biofloc system and the biofloc system offers higher growth, survival, and immunomodulation than control.
•Appropriate carbohydrate source is requiredinbiofloc based farming (BFT) to improve growth performance and water quality.•Carbohydrate sources influence heterotrophic bacteria and help providing immunity and protective response under BFT system.•Multigrain and millet flour like molasses can generate and maintain heterotrophs to improve shrimp performance and immunity.•CHO specific multi-fold upregulation in genes targeting proPO and antioxidant defense indicates immune regulatory function.
The JK Paper industry located at Rayagada discharges biologically untreated effluent more than the permissible limit prescribed by Pollution Control Board, Odisha in to the environment. The industry ...is seriously polluting the surrounding aquatic and terrestrial environment. No detailed intensive study was carried out by previous workers on this industry earlier. The present study aims at finding out the impact of effluent on the flora at the contaminated site. The chemically treated effluent (TE) contained significant amount of mercury and cadmium. The TE has high BOD, COD, dissolved solids and suspended solids when compared to normal river water at the site of discharge. The TE deteriorated the natural water bodies changing the physico-chemical properties of natural river water. After meeting the river water the TE was diluted after 1 km distance from the meeting point of the river. Crop plants collected from the contaminated site showed higher level of residual Hg and Cd and significant depletion in pigment was observed. Plants collected from both the sides of the treated effluent canal showed significant amount residue mercury and cadmium in the plant leaves. The plants exposed to the TE, showed variation in chlorophyll and Phaeophytin pigment content when compared to their respective control values in all terrestrial plants collected from the contaminated site. In some plant leaves little increment in the pigment level was noted but the values were not significant. The changes observed in the plant pigment might be due to heavy metal accumulation. The presence of residual Hg and Cd in crop plants and plant leaves grazed by grazing animals after absorption, accumulation and enrichment may lead to a possible biological magnification, warrants attention. Proper biological treatment, treatment of effluent by modern methods and removal of heavy metals from the effluent before discharge by the industry is suggested.
•Biological treatment of the effluent was not carried out by the industry & chemicals present in the effluent were significantly high..•The water quality of the river water deteriorated due to the discharge of effluent of the paper mill.•Plants collected from the contaminated site showed significant accumulation of cadmium and mercury in leaf tissues•Significant depletion in pigment content of exposed plant leaves was noticed.•Depletion in plant pigment was due to accumulation of cadmium and mercury in plant tissues absorbed from the effluent.
Abstract
The beneficial effects of two probiotic bacterial strains
Marinilactibacillus piezotolerans
and
Novosphingobium
sp. during the culture of Indian white shrimp,
Penaeus indicus,
under biofloc ...and clear water system were evaluated. The experimental variation were CW1 (
M. piezotolerans
in clear water), BFT1 (biofloc +
M. piezotolerans
), CW2 (
Novosphingobium
sp. in clear water), BFT2 (biofloc +
Novosphingobium
sp.) and control (without bacterial strains and biofloc). Growth and survival considerably increased in probiotic bio-augmented treatments. Probiotic incorporation significantly improved water quality, especially ammonia reduction. Microbiota analysis from gut samples taken from different treatments revealed varied microbial population structure among clear water culture, biofloc culture and control.
Proteobacteria
and
Firmicutes
were the top phyla observed in the treatments which were significantly higher in bio-augmented systems than the control.
Vibrio
genera were predominantly observed in control and clear water system compared to that of biofloc systems. Immune genes were significantly altered in response to probiotic gut microbial supplementation than the control. Higher gene expression profile of important immune genes was observed in the biofloc reared shrimps. Expression of digestive enzyme related genes such as trypsin, chymotrypsin, cathepsin L, cathepsin B and alpha amylase were also upregulated significantly in probiotic supplementation especially in the biofloc treatments. Proteomic analysis of hepatopancreas of shrimps from different treatments was carried out by using 2D gel electrophoresis and MALDI-TOF analysis. The proteins were mostly related to growth and stress tolerance. Eukaryotic initiation factor 4E binding protein was expressed in all the groups and it was high in biofloc treated animals followed by animals treated solely with probiotics compared to those of control groups. The results concludes that biofloc already proved as an effective culture method for healthy shrimp production and supplementation of probiotic bacterial strains registered additional benefit for growth, survival, microbial, immunological status of
P, indicus
culture.
Biofloc technology (BFT) is a novel modern aquaculture farming technique used to reduce toxic nitrogen concentration, act as in situ food source and eradicate pollutants using carbon and therefore to ...control C:N ratio in an aquaculture system. In this study, effect of different C:N ratios of a biofloc based system on water quality such as the level of Total ammonia nitrogen (TAN) nitrite-nitrogen (NO2−–N) and nitrate nitrogen (NO3−–N) were explored. Further, the growth and immunity status of shrimp L. vannamei under the influence of different C:N ratios were evaluated. Two of the C:N ratios (15 and 20) could significantly (P < 0.05) reduce TAN, NO2-N and NO3-N levels (0.456 ± 0.01, 0.145 ± 0.09, and 0.102 ± 0.02 ppm) compared to control (1.45 ± 0.1, 0.749 ± 0.14 and 0.675 ± 0.16 ppm). Large variations in the frequency distribution of operational taxonomic units (OTUs) for the bacterial community in water with different C:N ration (BFT) and control were observed. Vibrios often considered as opportunistic pathogens, where the most dominant bacterial flora of water in control (79%) and C:N5 (37%) group. In C:N10, Thauera (62%) was most represented genus. Similarly, Attheyaceae (56%), followed by Peridiniaceae (30%) were the most dominant groups in C:N15 treatment. The diversity of bacterial flora was more spread in C:N20 treatments with Psychrobacter (26%), Proteobacteria (25%) and Peridiniaceae (20%) as the major groups. The trend of Vibrio dominance decreased with the increase in C:N ratios and thus confirming the dominance of heterotrophic bacteria in high C:N ratio groups. Upon challenge with pathogens, shrimps from C:N10, C:N15 and C:N20 groups showed significantly higher survival (P < 0.05) compared to the C:N5 and control group. Similarly, better growth rate was also observed in BFT tanks compared to control both during the culture and at harvest. Comparatively higher expression of four immune-related genes (ras-related nuclear gene (RAN), serine proteinase gene (SP), prophenoloxidase activating enzyme (PPAE), and crustin were observed in different C:N ratio ponds than control and these were in increasing trend with the C:N ratio. Gene expression analysis showed that the transcripts of those immune genes were significantly increased among all C:N treatments than that of control. Overall, these findings demonstrated that with optimum C:N ratio, BFT can be used to optimize the bacterial community composition for both optimal water quality and optimal shrimp health. This study thus indicates the possibility of obtaining better performance of L. vannamei culture with proper adjustment of C:N ratio in a biofloc based system.
•Optimization of C:N ratio under biofloc based culture system to improve the growth performances and water quality parameters.•The heterotrophic microbial dominance was higher and vibrio load was lower with increase of C:N ratio levels.•Through metagenomics approach, differentiated microbial biomass and communities were recorded in various C:N ratio levels.•mRNA expression of immune genes like Crustin, RAN, SP, PPAE, were highly upregulated in various CN groups than control.
Shrimp farming is a technology-driven and risk-intensive food production system. Shrimp farms are remotely located and farmers need customized farm advisories, which the conventional extension ...systems are not able to provide. To provide technology advisories to the stakeholders, an android mobile application, CIBA ShrimpApp, was developed in 2018, based on the information and format requirements of the shrimp farmers using Java language as front end and the data bases were created as back end through Structured Query Language (MySQL). The app contains eight modules, viz. better management practices of shrimp farming, quantification of inputs, on-farm disease diagnosis, on-farm risk assessment, Frequently Asked Questions (FAQs) in shrimp farming, regulations, advisories and updates and posting queries which were integrated as a mobile application. The app has more than 27,500 cumulative downloads and has a rating of 4.5 out of 5.0. The application was found to have improved the knowledge level of end users to the tune of 20–37%. The Google firebase application data showed that 98.4% of users of CIBA ShrimpApp were free from errors and crashes. An evaluation study conducted among sample regular users indicated that the app aided in farm decision-making and its design functionality and extension service function were perceived to be efficient. Considering the all-pervading mobile phone connectivity and affordability, smart phone-based mobile applications and data analytics can play a significant role in shrimp farm advisory services and its sustainability.
•NiB assists in densification of 90W-6Ni-4Co heavy alloys.•In fully NiB-exchanged 90W-6Ni-4Co, W-rich ‘third’ phase was observed.•NiB-containing heavy alloys restrict shape distortion compared to ...90W-6Ni-4Co.•Addition of NiB in W-Ni-Co heavy alloy improves its mechanical behaviour.•Thermal expansion coefficient of the alloys decreases with NiB substitution.
Display omitted
In this work, the effect of NiB on densification, phase, microstructure, distortion and mechanical properties of conventionally sintered ternary 90W-6Ni-4Co heavy alloy has been investigated without altering (Ni+NiB)/Co ratio. No intermetallic phase was detected in the heavy alloys upon addition of NiB. Instead, the partial and complete exchange of Ni with NiB in 90W-6Ni-4Co has elicited relatively better densification (>99% theoretical), higher bulk hardness (HV3 ~ 389–396 VHN), higher hardness of matrix (~352 HV0.025) when the alloys were sintered at 1500 °C. In addition to W grains and matrix, the completely NiB-substituted heavy alloy (90W-6NiB-4Co) sintered at 1500 °C exhibits the occurrence of W-rich third phase which contains ~75 wt% of W. Although the samples prevented slumping at 1475 °C, elephant foot formation was found inevitable in the base composition (90W-6Ni-4Co) when sintering was carried out at 1500 °C. However, the decreased distortion parameter (from 24.8 to 8.5) with optimal NiB addition affirms the enhanced shape retention capability of 90W-3Ni-3NiB-4Co and 90W-6NiB-4Co heavy alloys. Room temperature compression test of WHAs sintered at 1475 °C was performed at a fixed strain rate of 0.1 s-1. No crack formation was observed in NiB containing samples up to 40% deformation. Moreover, the systematic addition of 3–6 wt% NiB resulted in lower coefficient of thermal expansion of NiB-containing heavy alloys in the temperature range of 400–600 °C.
PDF
