Most of world’s fish and seafood are produced by aquaculture, which is one of the biggest contributors to the world’s food security. The substantial increase in prices of conventional feed ingredients and the over-exploitation of natural resources are some of the biggest constraints to aquaculture production. To overcome this stress, different approaches and techniques are used, among which the use of non-conventional feed ingredients in the aquaculture sector is the most recent approach. Different non-conventional feed ingredients such as plant-based products, algae (both micro and macroalgae), single-cell protein (bacteria and yeast), and insect meal are currently used in aquaculture for sustainable food production. Amongst all these novel ingredients, insects have greater potential to replace fishmeal. The existence of about 1.3 billion tons of food and agriculture waste from the food chain supply poses a serious environmental threat. Insects are tiny creatures that can thrive on organic waste and thus can convert the waste to wealth by the bioconversion and nutritional upcycling of organic waste. Insects have the potential to recover nutrients from waste aquaculture products, and many fish species feed on insects naturally. Therefore, employing insects in the aquaculture sector to replace fishmeal is an eco-friendly approach. The present review briefly highlights emerging non-conventional feed ingredients, with special attention given to insects. The current review also focuses on the nutritional value of insects, factors affecting the nutritional value of insects, potential insects that can be employed in the aquaculture sector, the physiological response of fish when fed with insect meal, techno-functional properties of insect meal, and emerging approaches for addressing possible downsides of employing insect meal in fish diets. Finally, it suggests avenues for further research into these inventive fishmeal replacements.

Silver nanoparticles (AgNPs) are commonly used in numerous consumer products, including textiles, cosmetics, and health care items. The widespread usage of AgNPs results in their unavoidable discharge into the ecosystem, which pollutes the aquatic, groundwater, sediments, and marine environments. These nanoparticles (NPs) activate the production of free radicals reactive species in aquatic organisms that interrupt the functions of DNA, cause mitochondrial dysfunction, and increase lipid peroxidation, which terminates the development and reproduction both in vivo and in vitro. The life present in the aquatic ecosystem is becoming threatened due to the release and exploitation of AgNPs. Managing the aquatic ecosystem from the AgNP effects in the near future is highly recommended. In this review, we discussed the background of AgNPs, their discharge, and uptake by aquatic organisms, the mechanism of toxicity, different pathways of cytotoxicity, and bioaccumulation, particularly in aquatic organisms. We have also discussed the antimicrobial activities of AgNPs along with acute and chronic toxicity in aquatic groups of organisms.

The introduction of heavy metals by industries in the aquatic ecosystem is a threatening alarm for living organisms. Bioremediation is an eco-friendly and inexpensive technique as an alternative to chemical methods for wastewater treatment. Wastewater samples were collected from ponds receiving effluents from the Kot Lakhpat Industrial zone, Lahore (Pakistan). Heavy metal-resistant ciliate, Paramecium multimicronucleatum was isolated and characterized with the help of 18SrRNA biomarker. The ciliate showed optimum growth at 25 °C ± 1 °C and pH 7. Growth patterns of P. multimicronucleatum were observed with and without metal stress in wheat grain medium. The minimum inhibitory concentration of cadmium, copper, zinc, and lead was 60, 70, 110, and 160 μg ml⁻¹, respectively. The maximum uptake by Paramecia for Cd, Cu, and Zn was recorded as 90%, 82%, and 93% respectively after 96 h of exposure in each case. While 90% of lead ions were absorbed by Paramecium cells after 48 h of exposure. The order of uptake ability by Paramecium sp. was Zn²⁺ > Cd²⁺ > Cu²⁺ > Pb²⁺. This preliminary study of exploring bioremediation ability of this ciliate would be helpful for investigating it further using advanced molecular techniques.

The peachfruit fly,Bactrocera zonata(Saunders) is a polyphagous pest in nature, belonging to order,Dipteraand their respective family isTephritidae. It mostly feeds on different crops, vegetables and fruits. Different traditional chemical insecticides have been used to control this notorious pest. Excessive consumption of pesticides has become a major threat to the fresh fruits trade since many importing countries refused to accept the shipments due to public health and environmental concerns. There is a growing trend to control these pests using the most effective biological control methods and other preventive measures have been adopted for reducing their attacks. Fungal agents have been used as biological agents to manage the attack of different insects pest through biological means. The present study was conducted to assess the virulence of three entomopathogenic fungi,Metarhizium anisopliae,Beauveria bassianaandVerticillium lecanii,againstBactrocera zonatastages under different laboratory conditions. The results showed thatB. bassianaandM. anisopliaewere more effective in pathogenicity and potentially kill at all stages ofB. zonataas compared toV. lecanii. The highest mortality rate for the third larval instar and the pupal stage were recorded after exposure to the 1 × 10¹⁰conidia/ml concentrations,B. bassiana,with 68.67% and 89.67%, respectively. AdultB. zonataflies were the most susceptible to all entomopathogenic fungi. However,M. anisopliaewas more virulent againstB. zonataadult flies thanB. bassianaandV. lecaniiat 1 × 10¹⁰conidial concentration. Therefore, the entomopathogenic fungiB. bassianaandM. anisopliaecan be used as an cost effective bio-insecticide in the integrated pest management programs to controlB. zonata. This study will be helpful to overcome this pest through biological control means.

Azo dyes in textile industry effluent are one of the major toxic contaminants causing a severe threat to life. Bioremediation is the most cost-effective and environmentally beneficial innovative biotechnologically technique used to mitigate dyes’ toxic effects in aquatic environments. The purpose of the present study was to determine the azo dyes degradation potential of a ciliate, Paramecium caudatum, isolated from industrial wastewater. Under optimum conditions, P. caudatum was found to possess a 90.86% decolorizing ability of RR2 (reactive red), 83.06% of RB5 (reactive blue) and 85.43% of LY (Levafix reactive yellow) dyes. The P. caudatum showed maximum growth at 25 °C and pH 7.5 in the presence of azo dyes at a concentration of 20 ppm (0.02 mg/mL). After being exposed to RR2, RB5, and LY azo dyes, the level of GSH in P. caudatum increased for the control i.e., 54, 43, and 23%, respectively. Sequentially, the GSSG level decreased by 26% after treatment with the LY azo dye, while exposure to RR2 and RB5 enhanced the value by more than twofold and by 0.86%. The results for the decolorization and biodegradation of azo dyes indicated that P. caudatum is a potential candidate for the treatment of textile industry effluents.