Sudden fish deaths occurred during summer peaks in India and expected to be more in future. This study was conducted to explain the biochemical responses of Labeo rohita under extreme thermal condition (treated: 37–38°C against controlled: 28–30°C). Exposure of 14 days resulted in 30% of fish mortality. Glucose concentration was maintained in serum for both treated and controlled groups. However, triglycerides, protein, globulin, calcium, cholesterol and haemoglobin were declined and enzymes (glutamate‐pyruvate transaminase, GPT and glutamate‐oxalate transaminase, GOT) were elevated in serum in the treated group. Indicators of overall metabolism (biomolecules: glucose, triglycerides, protein, cholesterol; enzymes: GPT, GOT; and RNA: DNA) were diminished in liver, whereas these were less affected in muscle. Higher GPT, GOT and lower albumin in serum confirmed disturbance in hepatic panel. Simultaneously compromised growth (lower SGR, DNA content in liver) was observed in treated fish due to impaired metabolism. Extreme thermal stress induced by such catastrophic warmer water exposure caused liver problems and anaemia which ultimately caused fish death.

Dietary preference and feeding ecology of Nematalosa nasus (Bloch 1795) in Chilika lagoon, India, was investigated through analysis of prey items in the guts and that in the habitat. Of the 230 taxa identified from the habitat in plankton samples from the lagoon, thirty five taxa were recorded from the guts of the fish. Index of Relative Importance showed 80% of the food comprised of microplankton groups viz. Foraminifera (35.79%), Chlorophyceae (20.52%), Bacillariophyaceae (12.30%), Cyanophyaceae (6.53%), other plant matter (3.65%) and Euglenophyaceae (0.76%). The fish is a generalized feeder on microplankton, with specialization on foraminiferans and Chlorophyaceae in Chilika Lagoon. Diet composition varied significantly with seasons. Prey type selectivity showed, preference to Gyrosigma sp. (α i -0.98, e i -0.85), Synedra sp. (α i -0.47, e i -0.71), Tabellaria sp. (α i -0.58, e i -0.47) and Ulothrix sp. (α i -0.06, e i -0.34) during monsoon and post-monsoonseason. Ammoniabeccarii (α i -0.77 e i -0.98), Campylodiscus sp. (α i -0.04, e i -0.17) and Microspora sp. (α i -0.18, e i -0.76), were selected during pre-monsoon period, which is also the peak breeding period of the fish.

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We describe the synthesis of acid functionalized graphene (GE) which is grafted to chitosan (CH) by first reacting the oxidized GE with thionyl chloride to form acyl-chlorinated GE. This product is subsequently dispersed in chitosan and covalently grafted to form GE-chitosan. GE-chitosan is further grafted onto polymetanitroaniline (PMNA) by free radical polymerization conditions to yield GE-CH-PMNA. We have characterized the structure of synthesized GE-CH-PMNA composites by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), scanning electron microscopy, and conductivity measurements. XRD data suggest the strongly crystalline character of the prepared specimen. Our measurement shows that the dielectric constants of these nanocomposites are remarkably enhanced due to interfacial polarization effect. This study demonstrates that functionalized graphene sheets are ideal nanofillers for the development of new polymer composites with high dielectric constant values.

Acrylicacid was grafted onto chitosan by using the ceric ammonium nitrate as the initiator. The effect of initiator concentration, monomer concentration, time & temperature on % G and % GE were studied. The grafted samples were characterized using FTIR, TGA, SEM and XRD methods. From the FTIR data it was ascertained that grafting has occurred considerably. The morphology of the grafted polymer was observed from the SEM picture. The thermal analysis indicated the different stages of degradation of the grafted copolymer. Evidence of grafting was obtained from comparison of SEM, XRD, and FTIR of the grafted and nongrafted chitosan as well as solubility characteristics of the products. The antibacterial and antifungal activities of the grafted polymer have also been investigated.