The emergence of diseases and mortalities in aquaculture and development of antibiotics resistance in aquatic microbes, has renewed a great interest towards alternative methods of prevention and control of diseases. Nanoparticles have enormous potential in controlling human and animal pathogens and have scope of application in aquaculture. The present investigation was carried out to find out suitable nanoparticles having antimicrobial effect against aquatic microbes. Different commercial as well as laboratory synthesized metal and metal oxide nanoparticles were screened for their antimicrobial activities against a wide range of bacterial and fungal agents including certain freshwater cyanobacteria. Among different nanoparticles, synthesized copper oxide (CuO), zinc oxide (ZnO), silver (Ag) and silver doped titanium dioxide (Ag-TiO2) showed broad spectrum antibacterial activity. On the contrary, nanoparticles like Zn and ZnO showed antifungal activity against fungi like Penicillium and Mucor species. Since CuO, ZnO and Ag nanoparticles showed higher antimicrobial activity, they may be explored for aquaculture use.

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Enterovirus 71 (EV71) is an infectious virus affecting all age groups of people around the world. It is one of the major aetiologic agents for HFMD (hand, foot and mouth disease) identified globally. It has led to many outbreaks and epidemics in Asian countries. Infection caused by this virus that can lead to serious psychological problems, heart diseases and respiratory issues in children younger than 10 years of age. Many studies are being carried out on the pathogenesis of the virus, but little is known. The host immune response and other molecular responses against the virus are also not clearly determined. This review deals with the interaction between the host and the EV71 virus. We discuss how the virus makes use of its proteins to affect the host's immunity and how the viral proteins help their replication. Additionally, we describe other useful resources that enable the virus to evade the host's immune responses. The knowledge of the viral structure and its interactions with host cells has led to the discovery of various drug targets for the treatment of the virus. Additionally, this review focusses on the antiviral drugs and vaccines developed by targeting various viral surface molecules during their infectious period. Furthermore, it is asserted that the improvement of prevailing vaccines will be the simplest method to manage EV71 infection swiftly. Therefore, we summarise numerous vaccines candidate for the EV71, such as the use of an inactivated complete virus, recombinant VP1 protein, artificial peptides, VLPs (viral-like particles) and live attenuated vaccines for combating the viral outbreaks promptly.

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Suckermouth armoured catfish (Pterygoplichthys spp.) which is popularly called "Devil fish" in Andhra Pradesh, was recorded in 93.33% of fish ponds out of 600 ha surveyed in Krishna and West Godavari districts including mesohaline ponds wherein salinity ranges from 2 to 20‰. Pterygoplichthys spp. have ranged from 150 to 600 kg/ha that accounts to 2.01-7.50% of total biomass of fish harvested in aquaculture ponds leading to escalation of feed conversion ratio by 25.76%. Consequently, carp production has diminished by 18.88% to 22.92% leading to economic losses to fish farmers up to 13.40%. Food chain disruption by this alien fish is not only confined to benthic algae and periphyton but also foraging on supplementary feeds leaving primary fishes deprived from availing feed. Abundance of Pterygoplichthys spp populations in culture ponds as also in canals was high in monsoon season when compared to winter. Invasion and abundance of Pterygoplichthys spp in various river systems in Andhra Pradesh has become major concern for fishers causing extensive damage to nets and gears as also retarded catch per unit effort resulting in minimization of their income by 30%. Efforts to extract fish hydrolysate from Pterygoplichthys spp were futile due to intense bony skeleton and poor recovery rate which projected utilization of this fish for allied activities to minimum. Abundance of Pterygoplichthys spp is increasing in confined and open water bodies due to their tolerance and ability to grow and breed in variety of aquatic habitats including polluted environments as also lack of effective predators thus poses a high risk and threat to native freshwater species in any ecosystem in which they get established.

Clarias magur, popularly known as magur, is one of the economically important catfish species having high aquaculture potential in India due to its efficient food conversion, taste, and nutritional benefits. Due to habitat degradation, over exploitation, lack of resources, indiscriminate use of agricultural pesticides and introduction of competitor exotic species, the wild populations are dwindling day by day. According to IUCN, it is listed as endangered species. In the present study, the population genetic structure of 206 magur samples collected from seven different geographical regions was examined using partial mitochondrial D-loop (control region) sequence variation. In total of 17 haplotypes were observed with high number of private alleles, number of haplotypes ranged from 2 to 6 and maximum number of haplotypes was observed in UP population. Haplotype diversity and nucleotide diversity ranged from 0.06897 to 0.76322 and 0.00019 to 0.00208, respectively. Pairwise FST values ranged from 0.01383 to 0.62069 and highest genetic differentiation was observed between AP and AS population. Low genetic diversity and significant population genetic differentiation was observed in the present study. The information generated in the present investigation would facilitate formulating appropriate strategy for management, conservation, and genetic improvement program of this commercially important aquaculture species.