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991.
Pankaj Kumar 《Journal Of Aquatic Food Product Technology》2013,22(2):134-146
Incidence of Edwardsiella tarda in Asian stinging catfish, Heteropneustes fossilis (Bloch), and its sensitivity to antibiotics and sanitizers was studied. Five out of 10 representative lots of H. fossilis were positive for E. tarda. The minimum bactericidal concentration (MBC) of sanitizers (hydrogen peroxide, glutaraldehyde, benzalkonium chloride, sodium hypochlorite, and iodophor) on planktonic E. tarda varied with strains, suspending media (distilled water, physiological saline, pond water, and tryptic soy broth), and combination of factors. The time taken by the sanitizers to achieve 5-log reductions varied greatly between 1 min and 180 min at X and 2X MBCs of sanitizers. Benzalkonium chloride, glutaraldehyde, and sodium hypochlorite were effective in reducing the planktonic E. tarda at concentrations ranging from 3.13 ppm for glutaraldehyde to 25 ppm for sodium hypochlorite. Edwardsiella tarda strains were highly sensitive to ciprofloxacin and exhibited varying degrees of resistance to other antibiotics. 相似文献
992.
Feed rate is one of the important variables considered for the improvement in production of prawns. The effects of four feeding rates on growth, water quality and the nutrient budget of Penaeus latisulcatus were investigated for 98 days. The specific growth rate (SGR) at 3.0% feed rate was significantly higher than at all higher feed rates, and there was no significant difference in SGR between 4.5%, 6% and 7.5%. Total ammonia nitrogen concentrations in all treatments remained low in the safe range for prawn culture. Dissolved inorganic nitrogen and nitrate nitrogen were significantly higher (P < 0.05) in prawn tanks received feed rates of 6.0% and 7.5%. Total phosphorus and the soluble reactive phosphorus linearly increased with the progression of the trial and feeding rates. Nutrient conversion rates were significantly higher (P < 0.05) in prawns receiving the feeding rate of 3.0% than feeding rates of 6.0% and 7.5%. The lowest food conversion ratio was recorded at feeding rates of 3% and 4.5%. Nutrient budget showed that 6.01–15.99% nitrogen and 4.53–9.29% phosphorus of the nutrient inputs were retained in the prawn biomass. The results indicated that the growth and nutrient conversion rate may not increase with the increase above 3.0% of biomass per day. 相似文献
993.
Basanta Kumar Das Jyotirmayee Pradhan Swagatika Sahu Nilima Priyadarshini Marhual Bibudhendra Kumar Mishra Ambekar E Eknath 《Aquaculture Research》2013,44(6):918-927
The aim of this study was to evaluate dietary dosages of Microcystis on the immune response and disease resistance against infections due to the opportunistic pathogen Aeromonas hydrophila in Labeo rohita fingerlings. Labeo rohita fingerlings were fed diet containing 0 (Control), 0.5, 1.0 and 5 g Microcystis powder kg?1 dry diet for 90 days. Three replicate groups of fish averaging 20 ± 2 g were fed for 3 months daily. At 30 days interval, samples were assayed for different biochemical [serum total protein, albumin, globulin, albumin:globulin (A:G) ratio] and immunological (superoxide anion production, lysozyme and serum bactericidal activity) parameters. The results demonstrate that fish fed Microcystis showed increased levels of lysozyme, serum bactericidal activity, serum protein and albumin (P ≤ 0.05) as compared with the control group. After 90 days, fish were challenged with A. hydrophila and mortality (%) was recorded up to day 10 postchallenge. The group fed 1.0 g Microcystis kg?1 dry diet showed the highest percentage survival (72%). These results indicate that Microcystis aeruginosa stimulates the immunity and makes L. rohita more resistant to infection by A. hydrophila when fed in dried form in feed. 相似文献
994.
Anjil Kumar Srivastava Parul Singh Ashok Kumar Singh 《Pesticide biochemistry and physiology》2008,91(3):186-190
In this study, the genotoxic effects of insecticides in different phases of cell cycle were investigated in the mitotic cells of barley (Hordeum vulgare L.). The seeds of H. vulgare L. Var. Karan 4 were treated with different concentrations (0.05%, 0.1% and 0.5%) of insecticides alphamethrin (AM) and monocrotophos (MP) for 6 h after synchronization of cells in G1, S and G2 phase of cell cycle with the help of various presoaking durations (7 h, 17 h and 27 h.). Positive and negative control was run parallel in the form of ethyl methane sulphonate (EMS) and distilled water, respectively. The data indicate that higher dose of alphamethrin and monocrotophos produce toxicity, chromosomal aberrations and mitotic aberrations in Hordeum vulgare L. The present study indicates the genotoxic potential of the insecticides AM and MP and it also showed that S-phase of cell cycle was more sensitive compared to the G1 and G2 phases. 相似文献
995.
The innate immune system of fish is considered first line of defense against a broad spectrum of pathogens. Being a component of innate immunity and lying at the interface between fish and the aqueous environment, skin mucus plays a frontier role in protecting fish from infections. In the present study, skin mucus of Cirrhinus mrigala, Labeo rohita, Catla catla, Rita rita and Channa punctata, inhabiting different ecological niches, was analyzed to characterize potential innate immune factors such as lysozyme, proteases, phosphatases, esterase and sialic acid. The enzyme activities were high in bottom dweller species, C. punctata and C. mrigala, and low in clean water inhabiting species, L. rohita and C. catla. An inverse relationship was observed between the level of enzyme activity and the sialic acid content in these fish species. In R. rita, however, the levels of all factors were found to be low. Zymographic analysis with labeled Micrococcus lysodeikticus revealed three isoforms of lysozyme in C. punctata and two in each species, C. mrigala, L. rohita and C. catla. In R. rita, lysozyme could not be detected. Gelatin zymography revealed that serine and metalloproteases were the major mucus proteases in all fish species investigated. In addition, trypsin-like protease and Ca(++)-specific serine proteases were observed in skin mucus. Increased knowledge of these parameters could be useful in understanding the role of skin mucus in the innate immune system of fish species inhabiting different ecological niches. 相似文献
996.
Kumar N Jadhao SB Jha AK Kumar K Chandan NK Akhtar MS Aklakur M Kumar S Rana RS 《Fish physiology and biochemistry》2012,38(5):1343-1353
A 2-month preliminary study was conducted to delineate the effect of dietary methyl donors (choline, betaine, and lecithin) on the growth performance and metabolic status of Labeo rohita fingerlings subjected to endosulfan alone and in combination with elevated temperature. Four iso-caloric and iso-nitrogenous diets viz. basal diet, betaine-supplemented diet, choline-supplemented diet and lecithin-supplemented diet were prepared and fed to the different experimental groups throughout the experimental period as per the design. Two hundred and seventy fingerlings (average weight 7.95?±?0.04?g) were randomly distributed in six treatment groups each having three replicates. The experimental groups were as follows: fish subjected to normal water (without endosulfan) and fed with control diet (control group T(0)), fish subjected to endosulfan-treated water and fed with control diet (T(1)), fish subjected to concurrent exposure of endosulfan and elevated temperature and fed with control diet (T(2)), fish subjected to endosulfan and elevated temperature and fed with choline-supplemented diet (T(3)), fish subjected to endosulfan and temperature and fed with betaine-supplemented feed (T(4)), and fish subjected to endosulfan and temperature and fed with lecithin-supplemented feed (T(5)). The result shows that in both the groups, that is, endosulfan exposed and concurrent exposure to endosulfan and elevated temperature group of L. rohita the growth performance like percentage weight gain, feed conversion ratio and specific growth rates were significantly different (P?0.01) when fed with supplemented diet compared with control fed group. The liver LDH and MDH activity were significantly lower in lecithin, betaine, and choline fed groups. The muscle AST as well as G6PDH, AST, and ALT did not vary but liver ALT, gill and liver ATPase, intestine ALP, muscle and liver glycogen varied significantly with dietary supplementation. The liver and gill glutathione-S-transferase (GST) activities were significantly lower in methyl donors-supplemented groups and brain AChE activity showed lower inhibition in supplemented groups in both endosulfan alone and concurrently exposed endosulfan and temperature groups. The result obtained in this study concludes that inclusion of methyl donors, particularly lecithin and betaine in feed as nutritional supplements have potential to improve growth and stress mitigating effect in L. rohita fingerlings. 相似文献
997.
Dabas A Nagpure NS Kumar R Kushwaha B Kumar P Lakra WS 《Fish physiology and biochemistry》2012,38(2):469-482
The effects of different concentrations of cadmium chloride on the extent of lipid peroxidation (LPO) and alterations in the
antioxidant enzyme activities were studied in liver, kidney and gill tissues of freshwater murrel, Channa punctatus. The fish specimens were exposed to 6.7, 13.4 and 20.1 mg l−1 sublethal concentrations of cadmium chloride and the oxidative stress was assessed after 24, 48, 72 and 96 h post-exposure.
The biomarkers selected for the study were thiobarbituric acid reactive substances for assessing the extent of lipid peroxidation
and antioxidant defense system such as reduced glutathione (GSH), glutathione reductase (GR), glutathione peroxidase (GPX), glutathione-S-transferase (GST), catalase (CAT) and superoxide dismutase (SOD) activities. In general, the cadmium exposure
elevated the LPO in subject tissues of treated group and modulated the activities of GPx, GST, SOD, CAT, GR and level of GSH
after given exposure as compared to the control. All enzymes activities, except CAT (in kidney and gills), and amount of LPO
elevated significantly (P < 0.05) in treated group with respect to control in all tissues, while significant difference was not observed between the
exposed concentrations and within exposure duration. The results indicated that increase in LPO level and the fluctuation
in antioxidant defense system in fish could be due to cadmium-induced increase in the production of reactive oxygen species
(ROS). The potential role of these parameters as biomarkers of heavy metal pollution in aquatic system is discussed. 相似文献
998.
N. Sunil N. Sivaraj K. Anitha Babu Abraham Vinod Kumar E. Sudhir M. Vanaja K. S. Varaprasad 《Genetic Resources and Crop Evolution》2009,56(1):115-119
Jatropha curcas L., an important biodiesel plant, has been studied for its distribution and diversity in south east coastal zone of India
using DIVA-GIS. The Grid maps were generated on the distribution pattern, plant height, number of primary branches, collar
length, number of fruits per cluster and oil content. Flowering in the collected accessions were grouped in to very early
(35%), early (29%), medium duration (10%), late (20%), and very late (6%) types. Analysis for richness using rarefaction method
of DIVA-GIS showed that Ranga Reddy district of Andhra Pradesh is the potential area for germplasm with high oil content.
The present study revealed that diverse germplasm accessions of J. curcas are distributed all over the south east coastal zone and enabled us to find out gaps in collection and diversity richness
from SEC zone of India for conservation. 相似文献
999.
水分胁迫下外源ABA对甘蔗叶绿素荧光特性的影响(英文) 总被引:2,自引:0,他引:2
以抗旱甘蔗品种ROC 22与不抗旱品种ROC 16为材料,研究水分胁迫条件下外源ABA对2个甘蔗品种叶片叶绿素含量及叶绿素荧光特性的影响。结果表明,水分胁迫下,ROC 16的叶绿素降解程度高于ROC 22,而外源ABA能够缓解这种降解作用;随着水分胁迫的加剧,两个甘蔗品种叶片的基础荧光(Fo)显著升高,PSⅡ原初光能转化效率(Fv/Fm)和PSⅡ的潜在活性(Fv/Fo)显著下降,光适应下PSⅡ最大光化学效率(Fv’/Fm’)、PSⅡ实际光化学效率(ΦPS2)、光化学猝灭系数(qP)显著下降,表明水分胁迫使甘蔗叶片PSⅡ反应中心受到伤害,施加外源ABA能部分减轻这种伤害,以对ROC 22作用尤为显著。 相似文献