An overview of the ongoing insights in selenium research and its role in fish nutrition and fish health

Abstract

In the present review, the ongoing researches about selenium research in fish nutrition have been comprehensively discussed. Selenium research is getting popularity in fish nutrition as it is required for the normal growth and proper physiological and biochemical functions in fish. Its deficiency or surplus amounts create severe problems in fish. It is available as inorganic form, organic form, and nano form. In fish, most of the previous research is about the selenium requirements for fish by using only one selenium source mainly the inorganic one. Selenium shows maximum biological activity and bioavailability when it is supplied in proper form. However, to differentiate the more bioavailable and less toxic form of selenium, sufficient information is needed about the comparative bioavailability of different selenium forms in different fish species. In fish, important data about the new forms of selenoproteins is still scarce. Therefore, it is necessary to focus on the determination and elucidation of the new selenoproteins in fish through the utilization of recent approaches of molecular biology and proteomics. The adaptation of these new approaches will replace the old fashioned methodologies regarding the selenium research in fish nutrition. Moreover, the use of molecular biology and proteomics-based new approaches in combination with selenium research will help in optimizing the area of fish nutrition and will improve the feed intake, growth performance, and more importantly the flesh quality which has a promising importance in the consumer market.

Optimum selenium levels in diets high in plant‐based feedstuffs for gilthead sea bream (Sparus aurata) fingerlings

“…The essentiality of Se supplementation in fish has been discussed in several reviews (Antony Jesu Prabhu et al, 2016; Khan et al, 2017;Lall, 2002;NRC, 2011;Watanabe et al, 1997). In the present trial, an increase in dietary Se contents up to 1.00 mg Se/kg re- (Wang & Lovell, 1997).…”

“…The essentiality of Se supplementation in fish has been discussed in several reviews (Antony Jesu Prabhu et al, ; Khan et al, ; Lall, ; NRC, ; Watanabe et al, ). In the present trial, an increase in dietary Se contents up to 1.00 mg Se/kg resulted in a significant growth increase in terms of standard length and body weight, in agreement with a proportional increase in other growth parameters such as SGR.…”

“…The glutathione peroxidase ( gpx ) is among the most important selenoprotein family, as it forms part of one of two enzymatic systems present in vertebrates able to metabolise hydrogen peroxide to water (Di Giulio & Meyer, ; Holley, Bakthavatchalu, Velez‐Roman, & St. Clair, ). The gpx homologues have been studied in gilthead sea bream (Malandrakis et al, ), and its activity and expression of glutathione peroxidase 1a ( gpx1a ) gene have been used to evaluate Se requirements in fish species (Antony Jesu Prabhu et al, ; Khan et al, ). The other enzymatic systems able to dispose of hydrogen peroxide are catalases.…”

“…Se in toxic levels associates to sulphur containing amino acids due to its similar properties, thus altering the functional enzyme. Furthermore, under stressful conditions, Se requirements are increased, whereas under normal conditions these levels would be considered toxic (Khan, Zuberi, Fernandes, Ullah, & Sarwar, 2017). Se toxicity curses with reduced growth and feed efficiency, increased oxidative stress mortality, increased skeletal anomalies, oedema, decreased egg viability, altered immunological functions, necrosis of renal tubules and renal calcinosis, while deficiencies can produce reduced growth, mortality, lethargy, diminished appetite, muscle dystrophy, reduced vitamin E levels and low haematocrit (Bell, Cowey, Adron, & Pirie, 1987;Berntssen et al, 2018;Betancor et al, 2012;Choi et al, 2015;Gatlin & Wilson, 1984;Lin & Shiau, 2005;Pacitti et al, 2015;Saleh et al, 2014;Schultz & Hermanutz, 1990;Tashjian, Teh, Sogomonyan, & Hung, 2006;Watanabe et al, 1997;Zee, Patterson, Gagnon, & Hecker, 2016).…”

“…Selenium requirements vary not only among different species, but also according to developmental stage, sources of supplementation and environmental factors that may cause stress (Khan et al, 2017). The main criteria to evaluate requirements for Se in fish are growth, feed efficiency, tissue retention, antioxidant activity/expression markers and immune response/haematology (Antony Jesu Prabhu, Schrama, & Kaushik, 2016;Khan et al, 2017).…”