Search results for: fish pathogen

Authors: Kayode O. Afolabi, Benson C. Iweriebor, Anthony I. Okoh, Larry C. Obi

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Porcine circovirus type 2 (PCV2) is the major etiological viral agent of porcine multisystemic wasting syndrome (PWMS) and other porcine circovirus-associated diseases (PCVAD) of great economic importance in pig industry globally. In an effort to determine the status of swine herds in the Province as regarding the ‘small but powerful’ viral pathogen; a total of 375 blood, faecal and nasal swab samples were obtained from seven pig farms (commercial and communal) in Amathole, O.R. Tambo and Chris-Hani District Municipalities of Eastern Cape Province between the year 2015 and 2016. Three hundred and thirty nine (339) samples out of the total sample were subjected to molecular screening using PCV2 specific primers by conventional polymerase chain reaction (PCR). Selected sequences were further analyzed and confirmed through genome sequencing and phylogenetic analyses. The data obtained revealed that 15.93% of the screened samples (54/339) from the swine herds of the studied areas were positive for PCV2; while the severity of occurrence of the viral pathogen as observed at farm level ranges from approximately 5.6% to 60% in the studied farms. The Majority, precisely 15 out of 17 (88%) analyzed sequences were found clustering with other PCV2b reference strains in the phylogenetic analysis. More interestingly, two other sequences obtained were also found clustering within PCV2d genogroup, which is presently another fast-spreading genotype with observable higher virulence in global swine herds. This finding confirmed the presence of this all-important viral pathogen in pigs of the region; which could result in a serious outbreak of PCVAD and huge economic loss at the instances of triggering factors if no appropriate measures are taken to curb its spread effectively.

Keywords: pigs, polymerase chain reaction, porcine circovirus type 2, South Africa

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Authors: Uftah Ali M. Shushni, Viola Stuppec, Ulrike Lindequist

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Because of the evolving resistance of microorganisms to existing antibiotics, there is an increasing need for new antibiotics not only in human but also in veterinary medicine. As part of our ongoing work on the secondary metabolites produced by marine fungi, the organic extract of the culture filtrate of an Ascomycetous fungus, which was found on driftwood collected from the coast of the Greifswalder Bodden, Baltic Sea, Germany displayed antimicrobial activity against some fish and human pathogenic bacteria. Bioactivity-guided column chromatographic separation led to the isolation of 6-Deoxybostrycoidin. The structure was determined from the interpretation of spectroscopic data (UV, MS, and NMR). 6-Deoxybostrycoidin exhibited in vitro activity against Bacillus subtilis, Staphylococcus aureus and Flexibacter maritimus with minimal inhibitory concentrations of 25, 12.5 and 12.5 μg/ml respectively.

Keywords: marine fungi, fish pathogenic bacteria, microorganism, medicine

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Authors: Muhammad Naeem, Syed M. Moeen-ud-Din Raheel, Muhammad Arshad, Muhammad Naeem Qaisar, Muhammad Khalid, Muhammad Zubair Ahmed, Muhammad Ashraf

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Iron, Copper, Cadmium, Zinc, Manganese, Chromium levels were estimated to study the risk of trace elements on human consumption. The area of collection was Dera Ghazi Khan, Pakistan and was evaluated by means of flame atomic absorption spectrophotometer. The standards find in favor of the six heavy metals were in accordance with the threshold edge concentrations on behalf of fish meat obligatory by European and other international normative. Regressions were achieved for both size (length and weight) and condition factor with concentrations of metal present in the fish body.

Keywords: Oreochromis mossambica, toxic analysis, body size, condition factor

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Authors: V. Stejskal, K. Lundova, R. Sebesta, T. Vanina, S. Roje

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Pure strain of Arctic char (AC) Salvelinus alpinus and hybrid (HB) Salvelinus alpinus vs. Salvelinus fontinalis Mitchill belong to fish, which with great potential for culture in recirculating aquaculture systems (RAS). Aquaculture of these fish currently use flow-through systems (FTS), especially in Nordic countries such as Iceland (biggest producer), Norway, Sweden, and Canada. Four different water saturation regimes included normoxia (NOR), permanent hyperoxia (HYP), intermittent hyperoxia (HYP ± ) and regimes where one day of normoxia was followed by one day of hyperoxia (HYP1/1) were tested during 63 days of experiment in both species in two parallel experiments. Fish were reared in two identical RAS system consisted of 24 plastic round tanks (300 L each), drum filter, biological filter with moving beads and submerged biofilter. The temperature was maintained using flow-through cooler during at level of 13.6 ± 0.8 °C. Different water saturation regimes were achieved by mixing of pure oxygen (O₂) with water in three (one for each hyperoxic regime) mixing tower equipped with flowmeter for regulation of gas inflow. The water in groups HYP, HYP1/1 and HYP± was enriched with oxygen up to saturation of 120-130%. In HYP group was this level kept during whole day. In HYP ± group was hyperoxia kept for daylight phase (08:00-20:00) only and during night time was applied normoxia in this group. The oxygen saturation of 80-90% in NOR group was created using intensive aeration in header tank. The fish were fed with commercial feed to slight excess at 2 h intervals within the light phase of the day. Water quality parameters like pH, temperature and level of oxygen was monitoring three times (7 am, 10 am and 6 pm) per day using handy multimeter. Ammonium, nitrite and nitrate were measured in two day interval using spectrophotometry. Initial body weight (BW) was 40.9 ± 8.7 g and 70.6 ± 14.8 in AC and HB group, respectively. Final survival of AC ranged from 96.3 ± 4.6 (HYP) to 100 ± 0.0% in all other groups without significant differences among these groups. Similarly very high survival was reached in trial with HB with levels from 99.2 ± 1.3 (HYP, HYP1/1 and NOR) to 100 ± 0.0% (HYP ± ). HB fish showed best growth performance in NOR group reached final body weight (BW) 180.4 ± 2.3 g. Fish growth under different hyperoxic regimes was significantly reduced and final BW was 164.4 ± 7.6, 162.1 ± 12.2 and 151.7 ± 6.8 g in groups HY1/1, HYP ± and HYP, respectively. AC showed different preference for hyperoxic regimes as there were no significant difference in BW among NOR, HY1/1 and HYP± group with final values of 72.3 ± 11.3, 68.3 ± 8.4 and 77.1 ± 6.1g. Significantly reduced growth (BW 61.8 ± 6.8 g) was observed in HYP group. It is evident from present study that there are differences between pure bred Arctic char and hybrid in relation to hyperoxic regimes. The study was supported by projects 'CENAKVA' (No. CZ.1.05/2.1.00/01.0024), 'CENAKVA II' (No. LO1205 under the NPU I program), NAZV (QJ1510077) and GAJU (No. 060/2016/Z).

Keywords: recirculating aquaculture systems, Salmonidae, hyperoxia, abiotic factors

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Authors: Wen-Ting Wang, Wei-An Tsai, Rong-Hong Hsieh

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Long term taking high fat diet can lead to over production of energy, result in accumulation of body fat, dyslipidemia and increased lipid metabolism in the body. Over metabolism of lipid results in excessive reactive oxygen species and oxidative stress, may also cause mitochondrial dysfunction and cell death. Krill oil, fish oil and linseed oil are good sources of n-3 polyunsaturated fatty acids (PUFA). The present study investigated the effect of high fat diet and various oil rich of n-3 fatty acids on mitochondrial function and cell membrane composition. Six-weeks old male Spraque-Dawley rats were randomly divided into 8 groups including: control group, high fat diet group, low dosage and high dosage krill oil group, low dosage and high dosage fish oil group, and low dosage and high dosage linseed oil group. After 12 weeks of experimental period, the low dosage krill oil, fish oil group and linseed oil group with different dosage prevented mitochondrial dysfunction caused by high fat diet. The supplementation of different oils increased plasma, erythrocyte and mitochondrial n-3/n-6 ratio and further increased the proportion of PUFA in erythrocyte and mitochondrial membrane. It also decreased serum triglyceride (TG) and low density lipoprotein cholesterol (LDL-C) concentration. However, there was no significant change in serum total cholesterol (TC), high density lipoprotein cholesterol (HDL-C), biomarker of liver function, glucose, insulin, homeostasis model assessment-insulin resistance (HOMA-IR) and plasma malonadialdehyde (MDA) concentration when compared with high fat diet group. The supplementation of different sources of n-3 PUFA can maintain mitochondrial function and modulate cell membrane fatty acid composition in high fat diet conditions, and there is a positive relationship between mitochondrial function and mitochondrial membrane composition.

Keywords: fish oil, linseed oil, mitochondria, n-3 PUFA

Procedia PDF Downloads 390

Authors: Sahar Fahmy Mehanna

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Wild fisheries and aquaculture offer excellent opportunities to decrease hunger and improve nutrition, relieve poverty, create economic growth and guarantee healthier use of natural resources. Employment in fisheries and aquaculture has grown continuously quicker than in the agriculture sector, providing up to 55 million jobs worldwide. Fisheries and aquaculture supplied Egypt with 2.1 million tons of fish in 2021, mostly used as food for people. Fish production in Egypt has grown dramatically in the last three decades, where fish production increased from about 346 thousand tons in 1990 to up to 2.1 million tons in 2021. In contrast to natural resources, which increased by only 30% in the period from 1990 to 2021, aquaculture production increased by 2502% during the same period. The majority of wild fisheries production in Egypt arises from coastal areas, where pollution is one of the main challenges severely affected both the productivity and quality of fish stocks. Our marine resources are at the risk of irreversible loss to habitats, ecological functions, and biodiversity because of overfishing, pollution, destructive fishing methods, climatic changes, unsustainable coastal area development and the competing demands from different industrial uses and human activities. Illegal, Unreported and Unregulated (IUU) Fishing continues to be a big challenge to achieve sustainable fisheries. Furthermore, poor governance, management and practices are a further challenge. Reducing overfishing, stimulating responsible and sustainable fisheries management, applying aquaculture new and friendly practices and conserving the marine environment health are among the government’s best opportunities to provide highly nutritious food to the increasing population in Egypt. The present presentation will discuss the fishery regulations in the Egyptian marine fisheries that taken to maintain, protect and promote the different Egyptian marine environments and to what extent these regulations were effective.

Keywords: egypt, marine fisheries, fishery regulations, fisheries management, Marine ecosystem conservation

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Authors: Evanka Madan, Madhu Puri, Dan Zilberstein, Rohini Muthuswami, Rentala Madhubala

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The extensive interaction between the host and pathogen metabolic networks decidedly shapes the outcome of infection. Utilization of arginine by the host and pathogen is critical for determining the outcome of pathogenic infection. Infections with L. donovani, an intracellular parasite, will lead to an extensive competition of arginine between the host and the parasite donovani infection. One of the major amino acid (AA) sensing signaling pathways in mammalian cells are the mammalian target of rapamycin complex I (mTORC1) pathway. mTORC1, as a sensor of nutrient, controls numerous metabolic pathways. Arginine is critical for mTORC1 activation. SLC38A9 is the arginine sensor for the mTORC1, being activated during arginine sufficiency. L. donovani transport arginine via a high-affinity transporter (LdAAP3) that is rapidly up-regulated by arginine deficiency response (ADR) in intracellular amastigotes. This study, to author’s best knowledge, investigates the interaction between two arginine sensing systems that act in the same compartment, the lysosome. One is important for macrophage defense, and the other is essential for pathogen virulence. We hypothesize that the latter modulates lysosome arginine to prevent host defense response. The work presented here identifies an upstream regulatory role of LdAAP3 in regulating the expression of SLC38A9-mTORC1 pathway, and consequently, their function in L. donovani infected THP-1 cells cultured in 0.1 mM and 1.5 mM arginine. It was found that in physiological levels of arginine (0.1 mM), infecting THP-1 with Leishmania leads to increased levels of SLC38A9 and mTORC1 via an increase in the expression of RagA. However, the reversal was observed with LdAAP3 mutants, reflecting the positive regulatory role of LdAAP3 on the host SLC38A9. At the molecular level, upon infection, mTORC1 and RagA were found to be activated at the surface of phagolysosomes which was found to form a complex with phagolysosomal localized SLC38A9. To reveal the relevance of SLC38A9 under physiological levels of arginine, endogenous SLC38A9 was depleted and a substantial reduction in the expression of host mTORC1, its downstream active substrate, p-P70S6K1 and parasite LdAAP3, was observed, thereby showing that silencing SLC38A9 suppresses ADR. In brief, to author’s best knowledge, these results reveal an upstream regulatory role of LdAAP3 in manipulating SLC38A9 arginine sensing in host macrophages. Our study indicates that intra-macrophage survival of L. donovani depends on the availability and transport of extracellular arginine. An understanding of the sensing pathway of both parasite and host will open a new perspective on the molecular mechanism of host-parasite interaction and consequently, as a treatment for Leishmaniasis.

Keywords: arginine sensing, LdAAP3, L. donovani, mTORC1, SLC38A9, THP-1

Procedia PDF Downloads 98

Authors: Feny Mentang, Roike Iwan Montolalu, Henny Adeleida Dien, Kristhina P. Rahael, Tomy Moga, Ayub Meko, Siegfried Berhimpon

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Smoked fish is one of the famous fish products in North Sulawesi, Indonesia. Research in producing smoked fish using smoke liquid, and the use of that product as main taste for a new “natural condiment” have been done, including a series of researches to find materials for sachet. Research aims are to determine the effectiveness of smoked edible sachets, in preventing oxidation of natural condiment, stored in ambient temperature. Two kinds of natural condiment flavors were used, i.e. smoked Skipjack flavor, and Sea Food flavor. Three variables of edible sachets were used for the natural condiments, i.e. non-sachet, edible sachet without smoke liquid, and edible sachet with smoke liquid. The natural condiments were then stored in ambient temperature, for 0, 10, 20, and 30 days. To determine the effectiveness of edible sachets in preventing oxidation, analysis of TBA, water content, and pH were conducted. The results shown that natural condiment with smoked seafood taste had TBA values higher than that of smoked Skipjack. Edible sachet gave a highly significant effect (P > 0.01) on TBA. Natural condiment in smoked edible sachet has a lower TBA than natural condiment non-sachet, and with sachet without smoke liquid. The longer storing time, the higher TBA, especially for non-sachet and with sachet without smoke liquid. There were no significant effect (P > 0.05) of edible sachet on water content and pH.

Keywords: edible sachet, smoke liquid, natural condiment, oxidation

Procedia PDF Downloads 489

Authors: M. Kharroubi, Y. Rady, F. Bellali, S. Himmi

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The global objective of this study is to upgrade the sardine oil processed in Morocco by using enzymatic solutions. The specific objective of this part of study is to optimize the various parameters involved in enzymatic deacidification of fish oil processed in Morocco: pressure, ratio of oil/novozymes 435, ratio of oil/glycerol, temperature. The best deacidification yields were obtained with: -A temperature of 70 °C; -A ratio -Oil/Glycerol: 2% (% P); -A ratio -Oil/Novozyme 435: 1% (% P); -A pressure: 15 to 25 mbar. On the other hand, the study of the effect of initial oil acidity showed that whatever the acidity of the oil studied (very acidic, or low acidic), the final yields are high. Acidity does not reduce the reaction efficiency. From an industrial point of view, this represents a competitive advantage to consider. This eco-friend enzymatic solution may allows Moroccan fish oil producers to achieve acid number values that meet the standard.

Keywords: sardine oil, enzymatic esterfication, desacidification, acid number

Procedia PDF Downloads 356

Authors: Karen L. Middlemiss, Denham G. Cook, Peter Jaksons, Alistair Jerrett, William Davison

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Lateralisation of cognitive function is a common phenomenon found throughout the animal kingdom. Strong biases in functional behaviours have evolved from asymmetrical brain hemispheres which differ in structure and/or cognitive function. In fish, lateralisation is involved in visually mediated behaviours such as schooling, predator avoidance, and foraging, and is considered to have a direct impact on species fitness. Currently, there is very little literature on the role of lateralisation in fish schools. The yellow-eyed mullet (Aldrichetta forsteri), is an estuarine and coastal species found commonly throughout temperate regions of Australia and New Zealand. This study sought to quantify visually mediated behaviours in yellow-eyed mullet to identify the significance of lateralisation, and the factors which influence functional behaviours in schooling fish. Our approach to study design was to conduct a series of tank based experiments investigating; a) individual and population level lateralisation, b) schooling behaviour, and d) optic lobe anatomy. Yellow-eyed mullet showed individual variation in direction and strength of lateralisation in juveniles, and trait specific spatial positioning within the school was evidenced in strongly lateralised fish. In combination with observed differences in schooling behaviour, the possibility of ontogenetic plasticity in both behavioural lateralisation and optic lobe morphology in adults is suggested. These findings highlight the need for research into the genetic and environmental factors (epigenetics) which drive functional behaviours such as schooling, feeding and aggression. Improved knowledge on collective behaviour could have significant benefits to captive rearing programmes through improved culture techniques and will add to the limited body of knowledge on the complex ecophysiological interactions present in our inshore fisheries.

Keywords: cerebral asymmetry, fisheries, schooling, visual bias

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Authors: Adeyemi, Samuel Olusegun

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The paper reports on the result of experimental gill net assessment of the fishery of Gbedikere Lake in Kogi State between October 2006 and September 2008. Three stations A-C were sampled. Twelve species from ten families were represented in the experimental gill-net catches. These composed of families Protopteridae, Mormyridae, Clariidae, Mochokidae, Cichlidae, Cyprinidae, Malapteruridae, Osteoglossidae, Gymnarchidae, and Citharinidae. The Cichlids dominated the catches. This is made up of Oreochromis niloticus (17.90%), and Tilapia zilli (13.01%). These combined to make up 30.91% of the total number of fish caught. Also, the Cichlids formed 30.91% of the total catch by weight followed Heterotis niloticus (15.56%), Clarias gariepinus (13.16%), Gmynarchus niloticus (8.78%), Heterobranchus bidorsalis (7.14%), Synodontis nigrita (6.69%), Mormyrus rume (5.68%), Citharinus citharus (3.91%), Labeo senegalensis (2.93%), and Protopterus annectens (2.74%), respectively.

Keywords: experimental gill net, species diversity, abundance, distribution, Oxbow Lake and yield

Procedia PDF Downloads 476

Authors: M. A. Peribanez, G. Illan, I. De Blas, A. Muniesa, I. Ruiz-Zarzuela

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Intensive aquaculture is commonly associated with increased incidence of parasites. However, in Spain, the recent intensification of cyprinid production has not led to knowledge of the parasites that develop in the aquaculture facilities, the factors that affect their development and spread and the transmission between wild and cultivated fish species. The present study focuses on the knowledge of environmental factors, as well as host dependent factors, and their possible influence as risk factors in the incidence and intensity of parasitic infections. This work was conducted in the Duero River Basin, NW Spain. A total of 114 tenches (Tinca tinca) were caught in a fish farm and 667 specimens belonging to six species of cyprinid, not tench, in five rivers. An exhaustive search and microscopic identification of protozoa on skin and gills were carried out. Physical, chemical, and biological parameters of water samples from the capture points were determined. Only two ectoprotozoa were identified, Ichthyophthirius multifiliis and Tripartiella sp. In I. multifiliis, a high intensity of infection (more than 40 parasites on the body surface and more than 80 on gills) was determined in farmed tench (14%) and in Iberian barbel (Luciobarbus bocagei) (91%) and Duero nase (Pseudochondrostoma duriense) (71%) of middle stretches of rivers. The prevalence was similar between farmed tenches and cyprinids of middle courses. Tripartiella sp. was only found in barbels (prevalence in middle stretches, 0.7%) and in farmed tenches (63%), this species resulting in a high risk factor (odds ratio, OR= 1143) in the presence of the ciliate. There were no differences between the two species relative to the intensity of parasitization. Some of the physical, chemical and microbiological water quality parameters appear to be risk factors in the presence of I. multifiliis, with maximum OR of 8. Nevertheless, in Tripartiella sp., the risk is multiplied by 720 when the pH value exceeds 8.4, if we consider the total of the data, and it is increased more than 500 times if we only consider the values recorded in the fish farm (529 by nitrates > 3 mg/l; 530 by total coliforms > 100 CFU/100 ml). However, the high prevalence and risk of infection by I. multifiliis and Tripartiella sp. in fish farms should be related to environmental factors that dependent upon sampling point rather than in direct influence of the physical-chemical and biological parameters of the water. The high pH value recorded in the fish farm (9.62 ± 0.76) is the only parameter that we consider may have a substantial direct influence. Chronic exposure to alkaline pH levels can be a chronic stress generator, predisposing to parasitization by Tripartiella sp. In conclusion, often minor changes in ecosystem conditions, both natural and man-made, can modify the host-parasite relationship, resulting in an increase in the prevalence and intensity of parasitic infections in populations of cyprinids, sometimes causing disease outbreaks.

Keywords: cyprinids, fish, parasites, protozoa, risk factors

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Authors: Belinda Vega, Claudio Alvarez, Héctor Flores, Marcia Oliva, Katherine Alveal, Teresa Toro, María José Tapia, Fanny Guzmán

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With the increase in global temperatures and the decrease of oxygen (O2) concentration in the oceans, fish cultures are exposed to frequent fluctuations in dissolved O2 (DO) concentration that can cause chronic stress in the animals, altering the normal functioning of their immune system and making them vulnerable to infections, consequently increasing morbidity and mortality in the farms with economic losses. The mucosal organs (skin -and mucus-, gills, gut, and nasal mucosa) are the first line of defense of the fish against pathogens. Therefore, the objective of this study is to evaluate the effect of hypoxia on the antimicrobial activity of epidermal mucus from corvina drum (Cilus Gilberti), a native marine species with the potential for the diversification of aquaculture in Chile. To achieve this, the epidermal mucus of juveniles (~220g) kept under normoxia (7 mg/L DO) and hypoxia (2 mg/L DO) environmental conditions was collected after 6 weeks, as well as after 6 days of intraperitoneal inoculation with lipopolysaccharide from Vibrio anguillarum to induce an immune response in the fish. Total protein extracts of the mucus were used for bactericidal activity and lysozyme and peroxidase activity assays. Although the mucus from both experimental groups showed inhibitory effects on the bacterial growth of Vibrio anguillarum and Vibrio ordalli, this effect was more long-lasting in the normoxia group. We also observed a notable reduction in the presence of lysozyme in the mucus from fish exposed to hypoxia, with no differences in peroxidase content. Future proteomic studies of corvina mucus associated with the environmental conditions studied in this work will allow the isolation and identification of peptides with antimicrobial activity, those responsible for the results obtained. This will help establish strategies aimed at minimizing the impacts of hypoxia on the defense responses of corvina drum against potential pathogens. Funding: FONDECYT 3200440 and FONDECYT 1210056

Keywords: Cilus gilberti, mucus, antimicrobial activity, HYPOXIA

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Authors: Tiantian Ma

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The district of Doumen, Zhuhai has a sophisticated seabass value chain. However, unlike typical Global Value Chain (GVC) industries, the seabass value chain in Doumen is highly domestic both in terms of production and consumption. Still, since the highly-industrialized and capital-intensive industry involves many off-farm segments in both upstream and downstream, this paper will be utilizing the method of value chain analysis. To be specific, the paper will concentrate on two research goals: 1) the value chain mapping of the seabass industry, such as identifying actors in the hatchery, fish feed, fishponds, processing, logistics, and distribution, 2) the SWOT analysis of the seabass industry in Doumen, including incompetence of the waste disposal, the strategy of marketing, and the supportive role of the government, etc. In general, the seabass industry in Doumen is a sophisticated but not yet comprehensive value chain. It has achieved a lot in industrializing aqua-food products and fostering development, but there are still improvements that could be carried out, such as upholding environmental sustainability and promoting the brand better.

Keywords: agricultural value chain, fish farming, regional development, SWOT analysis, value chain mapping

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Authors: Adriana Martínez-Arias, John Josephraj Selvaraj, Luis Octavio González-Salcedo

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In the Colombian Pacific, Dorado fish (Coryphaena hippurus L.) fisheries is of great commercial interest. However, its habitat and fisheries may be affected by climatic change especially by the actual increase in sea surface temperature. Hence, it is of interest to study the dynamics of these species fishing zones. In this study, we developed Artificial Neural Networks (ANN) models to predict Catch per Unit Effort (CPUE) as an indicator of species abundance. The model was based on four oceanographic variables (Chlorophyll a, Sea Surface Temperature, Sea Level Anomaly and Bathymetry) derived from satellite data. CPUE datasets for model training and cross-validation were obtained from logbooks of commercial fishing vessel. Sea surface Temperature for Colombian Pacific were projected under Representative Concentration Pathway (RCP) scenarios 4.5 and 8.5 using Coupled Model Intercomparison Project Phase 5 (CMIP5) and CPUE maps were created. Our results indicated that an increase in sea surface temperature reduces the potential fishing zones of this species in the Colombian Pacific. We conclude that ANN is a reliable tool for simulation of climate change effects on the potential fishing zones. This research opens a future agenda for other species that have been affected by climate change.

Keywords: climatic change, artificial neural networks, dorado fish, CPUE

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Authors: Fateme Afkhami, Mohsen Ehsanpour, Maryam Ehsanpour, Majid Afkhami

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This study was conducted to determine the effects of polycyclic aromatic hydrocarbons (PAHs) on thyroidal hormones of Liza klunzingeri and to monitor marine pollution from northern part of Hormuz strait (Persian Gulf). Results showed the highest total PAHs levels (268.56 µg/kg) were in the fish samples and the lowest are obtained from water samples (3.12 µg/kg). Also, highest of PAHs levels in fish, sediment and water were found in St3. There was a positive correlation between T3 and T4, with PAHs results. T4 had a significant positive correlation (P<0.05).

Keywords: PAHs, thyroidal hormones, Liza klunzingeri, Hormuz Strait, Persian Gulf

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Authors: M. K. Sheikh, Y. M. Laghari., P. K. Lashari., N. T. Narejo

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The Indus River is one of the longest important rivers of the world in Asia that flows southward through Pakistan, merges into the Arabian Sea near the port city of Karachi in Sindh Province, and forms the Indus Delta. Fish are an important resource for humans worldwide, especially as food. In fish, healthy nutriments are present which are not found in any other meat source because it have a huge quantity of omega- 3 fatty acids, which are very essential for the human body. Ichthyologic surveys were conducted to explore the diversity of freshwater fishes, distribution, abundance and current status of the fishes at different spatial scale of the downstream, Indus River. Total eight stations were selected namely Railo Miyan (RM), Karokho (Kk), Khanpur (Kp), Mullakatiyar (Mk), Wasi Malook Shah (WMS), Branch Morie (BM), Sujawal (Sj) and Jangseer (JS). The study was carried in the period of January 2016 to December 2019 to identify River and biodiversity threats and to suggest recommendations for conservation. The data were analysed by different population diversity index. Altogether, 124 species were recorded belonging to 12 Orders and 43 Families from the downstream of Indus River. Among 124 species, 29% belong to high commercial value and 35% were trash fishes. 31% of fishes were identified as marine/estuarine origin (migratory) and 05% were exotic fish species. Perciformes is the most predominated order, contributing to 41% of families. Among 43 families, the family Cyprinidae was the richest family from all localities of downstream, represented by 24% of fish species demonstrating a significant dominance in the number of species. A significant difference was observed for species abundance in between all sites, the maximum abundance species were found at first location RM having 115 species and minimum observed at the last station JS 56 genera. In the recorded Ichthyofauna, seven groups were found according to the International Union for Conservation of Nature status (IUCN), where a high species ratio was collected, in Least Concern (LC) having 94 species, 11 were found as not evaluated (NE), whereas 8 was identified as near threatened (NT), 1 was recorded as critically endangered (CR), 11 were collected as data deficient (DD), and while 8 was observed as vulnerable (VU) and 3 endangered (EN) species. Different diversity index has been used extensively in environmental studies to estimate the species richness and abundance of ecosystems outputs of their wellness; a positive environment (biodiversity rich) with species at RM had an environmental wellness and biodiversity levels of 4.566% while a negative control environment (biodiversity poor) on last station JS had an environmental wellness and biodiversity levels of 3.931%. The status of fish biodiversity and river has been found under serious threat. Due to the lower diversity of fishes, it became not only venerable for fish but also risky for fishermen. Necessary steps are recommended to protect the biodiversity by conducting further conservative research in this area.

Keywords: ichthyofaunal biodiversity, threatened species, diversity index, Indus River downstream

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Authors: Dilek Zorlu Kaya, Sena Çenesiz, Utku Duran

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Infectious pancreatic necrosis virus is a disease of great concern in aquaculture, causing mortality of 80 - 90% of the stocks in salmonid production. We aimed to investigate the efficacy of quercetin on oxidant and antioxidant parameters of infectious pancreatic necrosis virus, which is important for fish farming and economy in vitro. Quercetin experimental model was used in the cell culture of Oncorhynchus mykiss infected with infectious pancreatic necrosis virus. Malondialdehyde, ceruloplasmin, total oxidant capacity, total antioxidant levels, and glutathione-peroxidase were measured in the samples. As a result of the study, it was observed that quercetin can minimize the damage caused by scavenging free radicals in cells infected with infectious pancreatic necrosis virus. Thus, we think that an important development can be achieved for fish farming and the economy.

Keywords: IPNV, oncorhynchus mykiss, TAS, TOS, quercetin

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Authors: John K. Mensah, Mary A. Sword Sayer, Ryan L. Nadel, George Matusick, Zhaofei Fan, Lori G. Eckhardt

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Leptographium terebrantis is an opportunistic root pathogen commonly associated with loblolly pine (Pinus taeda L.) stands that are undergoing a loss of vigor in the southeastern US. In order to understand the relationship between L. terebrantis inoculum density and host physiology, an artificial inoculation study was conducted in a five-year-old naturally regenerated loblolly pine stand over a 24 week period in a completely randomized design. L. terebrantis caused sapwood occlusions that increased in severity as inoculum density increased. The occlusions significantly reduced water transport through the stem but did not interfere with fascicle-level stomatal conductance or induce moisture stress in the saplings. The resilience of stomatal conductance among pathogen-infested saplings is attributed to the growth and hydraulic function of new sapwood that developed after artificial inoculation. Results demonstrate that faster-growing families of loblolly pine may be capable of tolerating the vascular root disease when the formation of new sapwood is supported by sustained crown health.

Keywords: hydraulic conductance, inoculum density, Leptographium terebrantis, Pinus taeda, sapwood occlusion

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Authors: Salina Saddick, Mohamed Afifi, Osama Abuznadah

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This study was carried out to determine the median lethal concentrations (LC50) of Zinc nanoparticles (ZnNPs) on Oreochromis niloticus and Tilapia zillii. The biochemical and molecular potential effects of ZnNPs (500 and 2000 μg L−1) on the antioxidant system in the brain tissue of O. niloticus and T. zillii were investigated. Four hundred fish were used for acute and sub-acute studies. ZnNP LC50 concentrations were investigated in O. niloticus and T. zillii. The effect of 500 and 2000 μg L−1 ZnNPs on brain antioxidants of O. niloticus and T. zillii was investigated. The result indicated that 69 h LC50 was 5.5 ± 0.6 and 5.6 ± 0.4 for O. nilotica and T. zillii, respectively. Fish exposed to 500 μg L−1 ZnNPs showed a significant increase in reduced glutathione (GSH), total glutathione (tGSH) levels, superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR), glutathione peroxidase (GPx) and glutathione-S-transferase (GST) activity and gene expression. On the contrary, malondialdehyde (MDA) levels significantly decreased. Meanwhile, fish exposed to 2000 μg L−1 ZnNPs showed a significant decrease of GSH, tGSH levels, SOD, CAT, GR, GPx and GST activity and gene expression. On the contrary, MDA levels significantly increased. It was concluded that, the 96 h LC50 of ZnNPs was 5.5 ± 0.6 and 5.6 ± 0.4 for O. nilotica and T. zillii, respectively. ZnNPs in exposure concentrations of 2000 μg/L induced a deleterious effect on the brain antioxidant system of O. nilotica and T. zillii. In contrast, ZnNPs in exposure concentrations of 500 μg L−1 produced an inductive effect on the brain antioxidant system of O. nilotica and T. zillii.

Keywords: ZnNPs, LC50, antioxidants, O. nilotica

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Authors: Yee-Seul So, Guiseppe Ianiri, Alex Idnurm, Yong-Sun Bahn

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Tor1 is a serine/threonine protein kinase that is widely conserved across eukaryotic species. Tor1 was first identified in Saccharomyces cerevisiae as a target of rapamycin (TOR). The TOR pathway has been implicated in regulating cellular responses to nutrients, proliferation, translation, transcription, autophagy, and ribosome biogenesis. Here we identified two homologues of S. cerevisiae Tor proteins, CNAG_06642 (Tor1) and CNAG_05220 (Tlk1, TOR-like kinase 1), in Cryptococcus neoformans causing a life-threatening fungal meningoencephalitis. Both Tor1 and Tlk1 have rapamycin-binding (RB) domains but Tlk1 has truncated RB form. To study the TOR-signaling pathway in the fungal pathogen, we attempt to construct the tor1Δ and tlk1Δ mutants and phenotypically analyze them. Although we failed to construct the tor1Δ mutant, we successfully construct the tlk1Δ mutant. The tlk1Δ mutant does not exhibit any discernable phenotypes, suggesting that Tlk1 is dispensable in C. neoformans. The essentiality of TOR1 is independently confirmed by constructing the TOR1 promoter replacement strain by using a copper transporter 4 (CTR4) promoter and the TOR1/tor1 heterozygous mutant in diploid C. neoformans strain background followed by sporulation analysis. To further analyze the function of Tor1, we construct TOR1 overexpression mutant using a constitutively active histone H3 in C. neoformans. We find that the Tor1 overexpression mutant is resistant to rapamycin but the tlk1Δ mutant does not exhibit any altered resistance to rapamycin, further confirming that Tor1, but not Tlk1, is critical for TOR signaling. Furthermore, we found that Tor1 is involved in response to diverse stresses, including genotoxic stress, oxidative stress, thermo-stress, antifungal drug treatment, and production of melanin. To identify any TOR-related transcription factors, we screened C. neoformans transcription factor library that we constructed in our previous study and identified several potential downstream factors of Tor1, including Atf1, Crg1 and Bzp3. In conclusion, the current study provides insight into the role of the TOR signaling pathway in human fungal pathogens as well as C. neoformans.

Keywords: fungal pathogen, serine/threonine kinase, target of rapamycin, transcription factor

Procedia PDF Downloads 195

Authors: Hacer Yeldan, Erhan Akamca, Sedat Gündogdu

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Length-Weight and Length-length relationship were estimated of 14 species Sparidae (Boops boops, Diplodus annularis, Diplodus cervinus, Dipladus puntazzo, Diplodus sargus, Diplodus vulgaris, Lithognathus mormyrus, Oblada melanura, Pagellus acarne, Pagellus erythrinus, Pagrus auriga, Pagrus caeruleostictus, Sarpa salpa, Sparus aurata) sampled from in the Northeastern Mediterranean Sea coast of Turkey, Iskenderun Bay. Samples were collected from July 2014 to June 2015, using bottom trawl and trammel net into three different depth; 0-10 m, 10-20 m, 20-50m. Length-length relationships were determined size measurements: standard length (SL) and fork length (FL) to total length (TL) for fish species. The relationships between TL, FL and TL, SL were all linear. The values of the exponent b of the length-weight relationships ranged between 2.685 and 3.473. The type of growth for fish species was algometric growth.

Keywords: Sparidae, Iskenderun bay, length-length, length-weight relationships

Procedia PDF Downloads 260

Authors: Pankaj Dinesh Baviskar

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This study examines the impact of curcumin-loaded nano-spheres in the form of emulsions on fish eye cataracts. Curcumin nanoemulsions were prepared by using phenethyl isothiocyanate. Nanoemulsions were synthesized by ultrasound-assisted method at 150 Watt. A zeta potential measurement for curcumin-loaded nanoemulsions was found to be -30.7eV, -13.4eV, and -9.55eV, and particle size was found to be 149.3 nm, 245.3 and nm 403.5 nm using particle size analyzer respectively for different conditions. The surface morphology of nano-spheres was examined by FE-SEM analysis. The zeta potential measured indicates its stability for corresponding nano-spheres. The anti-cataract application was studied by using isolated fish eye lenses. The cataract was induced using high glucose concentrated solution. The biochemical parameters in the form of reduced glutathione were measured to interpret the anti-cataract ability of curcumin-loaded nanoemulsions.

Keywords: curcumin, nano, cataract, nanoemulsion

Procedia PDF Downloads 87

Authors: Thangavelu Muthukumar, Thotapalli Parvathaleswara Sastry

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Collagen is the most abundantly available connective tissue protein, which is being used as a biomaterial for various biomedical applications. Presently, fish wastes are disposed improperly which is causing serious environmental pollution resulting in offensive odour. Fish scales are promising source of Type I collagen. Medicinal plants have been used since time immemorial for treatment of various ailments of skin and dermatological disorders especially cuts, wounds, and burns. Developing biomaterials from the natural sources which are having wound healing properties within the search of a common man is the need of hour, particularly in developing and third world countries. With these objectives in view we have developed a wound dressing material containing fish scale collagen (FSC) incorporated with Macrotyloma uniflorum plant extract (PE). The wound dressing composite was characterized for its physiochemical properties using conventional methods. SEM image revealed that the composite has fibrous and porous surface which helps in transportation of oxygen as well as absorbing wound fluids. The biomaterial has shown 95% biocompatibility with required mechanical strength and has exhibited antimicrobial properties. This biomaterial has been used as a wound dressing material in experimental wounds of rats. The healing pattern was evaluated by macroscopic observations, panimetric studies, biochemical, histopathological observations. The results showed faster healing pattern in the wounds treated with CSPE compared to the other composites used in this study and untreated control. These experiments clearly suggest that CSPE can be used as wound/burn dressing materials.

Keywords: collagen, wound dressing, Macrotyloma uniflorum, burn dressing

Procedia PDF Downloads 380

Authors: M. Thuanthong, W. Youravong, N. Sirinupong

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Nile tilapia (Oreochromis niloticus) is one of fish species cultured in Thailand with a high production volume. A lot of skin is generated during fish processing. In addition, there are many research reported that fish skin contains abundant of collagen. Thus, the use of Nile tilapia skin as collagen source can increase the benefit of industrial waste. In this study, Acid soluble collagen (ASC) was extracted at 5, 15 or 25 ˚C with 0.5 M acetic acid then the acid was removed out and collagen was concentrated by ultrafiltration-diafiltration (UFDF). The triple helix collagen from UFDF process was used as substrate to produce collagen peptides by alcalase hydrolysis in an enzymatic membrane reactor (EMR) coupling with 1 kDa molecular weight cut off (MWCO) polysulfone hollow fiber membrane. The results showed that ASC extracted at high temperature (25 ˚C) with 0.5 M acetic acid for 5 h still preserved triple helix structure. In the UFDF process, the acid removal was higher than 90 % without any effect on ASC properties, particularly triple helix structure as indicated by circular dichroism spectrum. Moreover, Collagen from UFDF was used to produce collagen peptides by EMR. In EMR, collagen was pre-hydrolyzed by alcalase for 60 min before introduced to membrane separation. The EMR operation was operated for 10 h and provided a good of protein conversion stability. The results suggested that there is a successfulness of UF in application for acid removal to produce ASC with desirable preservation of its quality. In addition, the EMR was proven to be an effective process to produce low molecular weight peptides with ACE-inhibitory activity properties.

Keywords: acid soluble collagen, ultrafiltration-diafiltration, enzymatic membrane reactor, ace-inhibitory activity

Procedia PDF Downloads 444

Authors: Mohamed Mahdi Alshahni, Takashi Tamura, Koichi Makimura

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Objective: The objective of this study is to evaluate roles of ABC-type efflux transporters in the resistance of Candida auris against common antifungal agents. Material and Methods: A wild-type C. auris strain and its antifungal resistant derivative strain that is generated through induction by antifungal agents were used in this study. The strains were cultured onto media containing beauvericin alone or in combination with azole agents. Moreover, expression levels of four ABC-type transporter’s homologs in those strains were analyzed by real time PCR with or without antifungal stress by fluconazole or voriconazole. Results: Addition of beauvericin helped to partially restore the susceptibility of the resistant strain against fluconazole, suggesting participation of ABC-type transporters in the resistance mechanism. Real time PCR results showed that mRNA levels of three out of the four analyzed transporters in the resistant strain were more than 2-fold higher than their counterparts in the wild-type strain under negative control and antifungal agent-containing conditions. Conclusion: C. auris is an emerging multidrug-resistant pathogen causing human mortality worldwide. Providing effective treatment has been hampered by the resistance to antifungal drugs, demanding understanding the resistance mechanism in order to devise new therapeutic strategies. Our data suggest a partial contribution of ABC-type transporters to the resistance of this pathogen.

Keywords: resistance, C. auris, transporters, antifungi

Procedia PDF Downloads 135

Authors: Syed Makhdoom Hussain, Muhammad Afzal, Farhat Jabeen, Arshad Javid, Tasneem Hameed

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A feeding trial was conducted with Cirrhinus mrigala fingerlings to study the effects of microbial phytase with graded levels (0, 500, 1000, 1500, and 2000 FTUkg-1) by sunflower meal based diet on growth performance and nutrient digestibility. The chromic oxide was added as an indigestible marker in the diets. Three replicate groups of 15 fish (Average wt 5.98 g fish-1) were fed once a day and feces were collected twice daily. The results of present study showed improved growth and feed performance of Cirrhinus mrigala fingerlings in response to phytase supplementation. Maximum growth performance was obtained by the fish fed on test diet-III having 1000 FTU kg-1 phytase level. Similarly, nutrient digestibility was also significantly increased (p<0.05) by phytase supplementation. Digestibility coefficients for sunflower meal based diet increased 15.76%, 17.70%, and 12.70% for crude protein, crude fat and apparent gross energy as compared to the reference diet, respectively at 1000 FTU kg-1 level. Again, maximum response of nutrient digestibility was recorded at the phytase level of 1000 FTU kg-1 diet. It was concluded that the phytase supplementation to sunflower meal based diet at 1000 FTU kg-1 level is optimum to release adequate chelated nutrients for maximum growth performance of C. mrigala fingerlings. Our results also suggested that phytase supplementation to sunflower meal based diet can help in the development of sustainable aquaculture by reducing the feed cost and nutrient discharge through feces in the aquatic ecosystem.

Keywords: sunflower meal, Cirrhinus mrigala, growth, nutrient digestibility, phytase

Procedia PDF Downloads 279

Authors: U.K. Sarkar, G. Karnatak, P. Mishal, Lianthuamluaia, S. Kumari, S.K. Das, B.K. Das

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Inland open water fisheries provide food, income, livelihood and nutritional security to millions of fishers across the globe. However, the open water ecosystem and fisheries are threatened due to climate change and anthropogenic pressures, which are more visible in the recent six decades, making the resources vulnerable. Understanding the interaction between meteorological parameters and inland fisheries is imperative to develop mitigation and adaptation strategies. As per IPCC 5th assessment report, the earth is warming at a faster rate in recent decades. Global mean surface temperature (GMST) for the decade 2006–2015 (0.87°C) was 6 times higher than the average over the 1850–1900 period. The direct and indirect impacts of climatic parameters on the ecology of fisheries ecosystem have a great bearing on fisheries due to alterations in fish physiology. The impact of meteorological factors on ecosystem health and fish food organisms brings about changes in fish diversity, assemblage, reproduction and natural recruitment. India’s average temperature has risen by around 0.7°C during 1901–2018. The studies show that the mean air temperature in the Ganga basin has increased in the range of 0.20 - 0.47 °C and annual rainfall decreased in the range of 257-580 mm during the last three decades. The studies clearly indicate visible impacts of climatic and environmental factors on inland open water fisheries. Besides, a significant reduction in-depth and area (37.20–57.68% reduction), diversity of natural indigenous fish fauna (ranging from 22.85 to 54%) in wetlands and progression of trophic state from mesotrophic to eutrophic were recorded. In this communication, different applications of biometeorology in inland fisheries management with special reference to the assessment of ecosystem and species vulnerability to climatic variability and change have been discussed. Further, the paper discusses the impact of climate anomaly and extreme climatic events on inland fisheries and emphasizes novel modeling approaches for understanding the impact of climatic and environmental factors on reproductive phenology for identification of climate-sensitive/resilient fish species for the adoption of climate-smart fisheries in the future. Adaptation and mitigation strategies to enhance fish production and the role of culture-based fisheries and enclosure culture in converting sequestered carbon into blue carbon have also been discussed. In general, the type and direction of influence of meteorological parameters on fish biology in open water fisheries ecosystems are not adequately understood. The optimum range of meteorological parameters for sustaining inland open water fisheries is yet to be established. Therefore, the application of biometeorology in inland fisheries offers ample scope for understanding the dynamics in changing climate, which would help to develop a database on such least, addressed research frontier area. This would further help to project fisheries scenarios in changing climate regimes and develop adaptation and mitigation strategies to cope up with adverse meteorological factors to sustain fisheries and to conserve aquatic ecosystem and biodiversity.

Keywords: biometeorology, inland fisheries, aquatic ecosystem, modeling, India

Procedia PDF Downloads 172

Authors: Zoran Herceg, Višnja Stulić, Tomislava Vukušić, Anet Režek Jambrak

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High voltage electrical discharge is a new technology used for inactivation of pathogen microorganisms. Pathogen yeasts can cause diseases in humans if they are ingested. Nowadays new technologies have become the focus of researching all over the world. Rhodotorula is known as yeast that can cause diseases in humans. The aim of this study was to examine whether the high voltage electrical discharge treatment generated in gas phase has an influence on yeast reduction and recovery of Rhodotorula spp 74 in pure culture. Rhodotorula spp. 74 was treated in 200 mL of model solution. Treatment time (5 and 10 min), frequency (60 and 90 Hz) and injected gas (air or argon 99,99%) were changed. Titanium high voltage needle was used as high voltage electrode (positive polarity) through which air or argon was injected at the gas flow of 0.6 L/min. Experimental design and statistical analyses were obtained by Statgraphics Centurion software (StatPoint Technologies, Inc., VA, USA). The best inactivation rate 1.7 log10 reduction was observed after the 10 min of treatment, frequency of 90 Hz and injected air. Also with a longer treatment time inactivation rate was higher. After the 24 h recovery of treated samples was observed. Therefore the further optimization of method is needed to understand the mechanism of yeasts inactivation and cells recovery after the treatment. Acknowledgements: The authors would like to acknowledge the support by Croatian Science Foundation and research project ‘Application of electrical discharge plasma for preservation of liquid foods’.

Keywords: rhodotorula spp. 74, electrical discharge plasma, inactivation, stress response

Procedia PDF Downloads 212

Authors: Nitin Pipralia, Amit Kmar Sinha, Gudrun de Boeck

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Atmospheric carbon dioxide (CO2) concentrations have been increasing since the beginning of the industrial revolution due to combustion of fossils fuel and many anthropogenic means. As the number of scenarios assembled by the International Panel on Climate Change (IPCC) predict a rise of pCO2 from today’s 380 μatm to approximately 900 μatm until the year 2100 and a further rise of up to 1900 μatm by the year 2300. A rise in pCO2 results in more dissolution in ocean surface water which lead to cange in water pH, This phenomena of decrease in ocean pH due to increase on pCO2 is ocean acidification is considered a potential threat to the marine ecosystems and expected to affect fish as well as calcerious organisms. The situation may get worste when the stress of salinity adds on, due to migratory movement of fishes, where fish moves to different salinity region for various specific activities likes spawning and other. Therefore, to understand the interactive impact of these whole range of two important environmental abiotic stresses (viz. pCO2 ranging from 380 μatm, 900 μatm and 1900 μatm, along with salinity gradients of 32ppt, 10 ppt and 2.5ppt) on the ecophysiologal performance of fish, we investigated various biological adaptive response in European sea bass (Dicentrarchus labrax), a model estuarine teleost. Overall, we hypothesize that effect of ocean acidification would be exacerbate with shift in ambient salinity. Oxygen consumption, ammonia metabolism, iono-osmoregulation, energy budget, ion-regulatory enzymes, hormones and pH amendments in plasma were assayed as the potential indices of compensatory responses.

Keywords: ocean acidification, sea bass, pH climate change, salinity

Procedia PDF Downloads 204