Lycopene reduces the impacts of aquatic environmental pollutants and physical stressors in fish Mahmoud A.O. Dawood 1 , Mohsen Abdel-Tawwab 2 and Hany M.R. Abdel-Latif 3 1 Department of Animal Production, Faculty of Agriculture, Kafrelsheikh University, Kafrelsheikh, Egypt 2 Department of Fish Biology and Ecology, Central Laboratory for Aquaculture Research, Agriculture Research Center, Abbassa, Egypt 3 Department of Poultry and Fish Diseases, Faculty of Veterinary Medicine, Alexandria University, Edfina, Egypt Correspondence Mahmoud A.O. Dawood, Department of Animal Production, Faculty of Agriculture, Kafrelsheikh University, 33516 Kafrelsheikh, Egypt. Email: mahmouddawood55@gmail.com Received 9 February 2020; accepted 10 May 2020. Abstract Aquatic organisms are susceptible throughout their lives to chemical and physical stressors, which negatively affect their health. Various aquatic pollutants derived from industrial effluents, overuse of some agricultural pesticides, herbicides and insecticides may cause devastating toxicological aspects of aquatic organisms and deteriorate their health and growth. They also led to oxidative stress to fish due to the stimulation of the production of reactive oxygen species. Therefore, the need for using natural antioxidants to be used as feed additives is of great importance to counteract the hazardous oxidative stress responses. The use of phytochemicals, which characterized by substantial antioxidative effects, has been raised. Lycopene is the principal carotenoid pigment found in tomatoes and their products, vegeta- bles and red fruits. Numerous studies have recommended the use of lycopene as a powerful antioxidant to attenuate the oxidative stress responses in several fish spe- cies exposed to various toxicants or any other stress conditions. Lycopene main- tains the health condition of fish by enhancing the immune and antioxidative responses. This review article aimed to elucidate the current information about the potential use of dietary lycopene for several fish species and its capability to attenuate the oxidative stress and haemato-immunological alterations resulted from aquatic environmental pollutants and other physical stressors. Additionally, the review discusses some aspects regarding the lycopene mode of action to assess the profits that would be of importance in the aquaculture industry. Key words: aquatic toxicity, environmental stressors, fish, lycopene, oxidative stress, phytochemicals. Introduction A wide range of pollutants such as pesticides and herbicides may extensively reach the aquatic ecosystems either directly or indirectly, causing life-threatening and dangerous envi- ronmental concerns to the living aquatic organisms (Joseph & Raj, 2011). They can reach the rearing water through the drainage water, which left from the agriculture sector (Fior- ino et al., 2018; Stara et al., 2020). The drainage water con- tains non-biodegradable pollutants, pesticides and herbicides that can be adsorbed by sediment particles and/ or bioaccumulated inside the tissues of the aquatic organ- isms (Torre et al., 2013; El Megid et al., 2020). It may, in turn, negatively affect the human beings who consume the intoxicated fish resulting in dangerous health risks (Dural et al., 2007; Abdel-Latif et al., 2020a). These toxicants induce immunosuppression and oxidative stress on aquatic animals (Abdel-Tawwab et al., 2017a; Abdel-Tawwab et al., 2017b). A wide range of functional feed additives is successfully included in aquafeed to enhance the feed efficiency, immune response, antioxidative status and disease resis- tance (Dawood et al., 2018; El Basuini et al., 2020; Abdel- Latif et al., 2020b). Carotenoids, including lycopene, are a group of fat-soluble pigments found in vegetables, toma- toes, fruits and their byproducts (Visioli et al., 2003; Tapiero et al., 2004). Various studies have considered their potentiality in counteracting the oxidative stress and improve fish growth performance (Rashidian et al., 2020). Lycopene described as a naturally occurring carotenoid that shows efficient antioxidants activity (Amarowicz, 2011; © 2020 John Wiley & Sons Australia, Ltd 1 Reviews in Aquaculture, 1–16 doi: 10.1111/raq.12455