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A comprehensive icthyoparasotological survey among estuarine and freshwater fishes of West Bengal, India revealed Trichodinella sunderbanensis sp. nov. and Trichodina acuta Lom, 1961 from an estuarine fish Mystus gulio (Hamilton, 1822) from the Vidyadhari river; Trichodina nandusi sp. nov. from a freshwater fish, Nandus nandus (Hamilton-Buchanan); Chilodonella hexasticha (Kiernik, 1909) Kahl, 1931 from freshwater fishes Labeo rohita (Hamilton, 1822); and Cyprinus carpio Linnaeus, 1758 from the Rupnarayan river. Taxonomic description of all the species based on wet silver nitrate impregnation method along with additional comments based on scanning electron microscopic descriptions of T. nandusi sp. nov. are also provided in this paper. Prevalence rate, morphometric parameters and comparisons with closely related species are also discussed.

The present study has been carried out to find out the prevalence of ectoparasites of carp fingerlings during different months of the year

We have synthesised a novel nanocomposite film by incorporating copper and cobalt nanoparticles, prepared by the method of trituration, in the poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) films by simple solution-casting technique. Fourier transform infrared spectroscopy (FTIR) study of these nanocomposite films detected presence of α-and β-phases. Scanning electron micrographs showed spherulitic crystal structure of PVDF-HFP in the nanocomposite film and study of dielectric properties over broadband frequency of these doped nanocomposite film showed that these films have higher dielectric permittivity and significantly lower dissipation factor (tanδ) at room temperature compared to the pure PVDF-HFP. The incorporation of metallic nanoparticles in the polymer matrix activates the transition of phase between α and β and provides the nanocomposites higher mobile charge carriers which participate in the interfacial polarisation. The room temperature dielectric constant of the pure PVDF-HFP at 20 Hz frequency increases with increase in concentration of the metal nanoparticles and reaches a maximum almost four times the value of the pure one. At higher concentrations, the effect reduces, perhaps due to agglomeration of the nanoparticles. The metal nanoparticles, obtained by the method of trituration, are inexpensive, easy to fabricate and environment friendly. Thus, their incorporation in polymer matrix to get enhanced electrical properties will have a significant contribution to the present day research.