Iranian Scientific Fisheries Journal

fa مقاله علمی – پژوهشی:‌ مقایسه اثرات منابع سلنیوم آلی و معدنی بر عملکرد رشد، ترکیب لاشه و مقاومت به استرس شوری، قطع هوادهی و افزایش ناگهانی تراکم جمعیت در کپور معمولی (Cyprinus carpio Linnaeus, 1758) Comparison of the effects of organic and inorganic selenium resources on growth performance, carcass composition, and resistance to salinity stress, aeration interruption, and sudden increase in population density in common carp (Cyprinus carpio Linnaeus, 1758) تغذيه تغذيه كاربردي Applicable سلنیوم (Se) به عنوان یک ریزمغذی حیاتی، در فرآیندهای متابولیک، سیستم ایمنی و تولیدمثل ماهیان مؤثر است. این مطالعه به‌ منظور ارزیابی تأثیر منابع و سطوح مختلف سلنیوم بر رشد و مقاومت به استرس در ماهی کپور معمولی انجام شد. اثرات شش تیمار غذایی شامل: 1- حاوی 3/0 میلی‌‌گرم سلنیوم اویلاسلنیوم در هر کیلوگرم غذا، 2- حاوی 1 میلی‌‌گرم سلنیوم اویلاسلنیوم در هر کیلوگرم غذا، 3- حاوی 3/0 میلی‌‌گرم سلنیوم سل‌‌استار در هر کیلوگرم غذا، 4- حاوی 3/0 میلی‌‌گرم سلنیوم سلنیت سدیم در هر کیلوگرم غذا، 5- حاوی 1 میلی‌‌گرم سلنیوم سلنیت سدیم در هر کیلوگرم غذا و 6- شاهد فاقد مکمل سلنیومی بر گونه کپور معمولی (Cyprinus carpio) مورد ارزیابی قرار گرفت. آزمایش در قالب یک طرح کاملاً تصادفی با ۲ تکرار برای هر تیمار و به مدت ۵۲ روز در مخازن ۲۵۰ لیتری با تراکم ۳۱ عدد ماهی در هر مخزن (میانگین وزن اولیه: 33/0±62/1 گرم) انجام شد. تفاوت معنی‌داری در وزن نهایی، طول استاندارد و ضریب چاقی بین تیمارها مشاهده نشد (05/0<p). سلنیوم اثر معنی‌‌داری بر نرخ زنده‌‌مانی طی دوره پرورش، درصد ماده خشک، پروتئین خام و خاکستر لاشه نداشت (05/0<p). تغذیه با اویلاسلنیوم یا سلنیت سدیم به میزان 3/0 میلی‌‌گرم در هر کیلوگرم غذا سبب کاهش معنی‌‌دار درصد چربی خام لاشه گردید (05/0>p). پس از استرس شوری و قطع هوادهی، تفاوت معنی‌داری در مدت زنده‌مانی مشاهده نشد (05/0<p). بعد از استرس شوری همراه با هوادهی، تیمار سلنیت سدیم به طور معنی‌‌داری مدت زنده ماندن را افزایش داد (05/0>p). استفاده از اویلاسلنیوم بهبودی نسبی در زنده‌مانی ایجاد کرد، اما در مقایسه با شاهد اثر معنی‌داری نداشت (05/0<p) درحالی‌که استفاده از سلنیوم سل‌‌استار موجب کاهش معنی‌‌دار مدت زنده ماندن گردید (05/0>p). در مجموع، بهترین نتیجه با مصرف سلنیت سدیم در سطح بهینه 3/0 میلی‌‌گرم سلنیوم در هر کیلوگرم جیره به‌‌دست آمد. Introduction Aquaculture makes a significant contribution to food production for the world population, plays a decisive role in international trade, and offers potential solutions to food security challenges (Mihaly-Karnai et al., 2025). Due to overfishing and in order to restore the stocks of common carp (Cyprinus carpio), responsible institutions are taking steps to artificially propagate this fish and release it into the wild. Unfortunately, in recent years, due to various reasons including reduced rainfall and excessive water withdrawal for agricultural purposes, it is not far-fetched that when releasing juvenile fish into the wild, they may encounter salinity stress (Roohi et al., 2017). Frequent power outages and subsequent aeration interruptions in recent years have caused oxygen deficiency stress, especially in intensive farming. With the continuous increase in the intensity of fish population density in advanced aquaculture, unfavorable conditions such as overpopulation stress, oxygen deficiency and poor nutrition have been created in the aquaculture process, and these will easily lead to oxidative stress. The damage of oxidative stress is very prominent in production and therefore it is necessary to solve the problem of stress in aquaculture animals (Li et al., 2023). Selenium (Se) improves the body's antioxidant capacity, prevents oxidative stress, enhances immunity and improves body health (Jingyuan et al., 2020; Wischhusen et al., 2020). Many studies have been conducted on the effects of selenium on various fish species, but few studies have been reported on common carp, Cyprinus carpio, (Mustafa and Omar, 2024) although common carp is one of the most important farmed fish species in the world (Adineh et al., 2018). Availa-Se is a zinc-L-selenomethionine complex and is used as a food additive to provide organic selenium in animal feed. Selstar is a type of organic selenium chelated with a mixture of amino acids for adding to the feed of various animals. Today, some researchers believe that the use of selenite in industry is questionable due to the high toxicity of inorganic selenium, its pro-oxidant quality and its bioavailability (Moustafa et al., 2024). The aim of the present study was to determine the effect of sodium selenite on the common carp species in comparison with the two commercial organic selenium compounds mentioned above. For this purpose, growth performance, carcass composition and resistance to salinity stress and oxygen deficiency in common carp were investigated. Methodology The effects of six dietary treatment containing 0.3 mg Se from Availa-Se (Treatment 1), 1 mg Se from Availa-Se (Treatment 2), 0.3 mg Se from Selstar (Treatment 3), 0.3 mg Se from sodium selenite (Treatment 4), 1 mg Se from sodium selenite (Treatment 5) per kg of diet, and a control diet without Se supplementation (Treatment 6) were investigated in common carp for 52 days. Each dietary treatment was studied in 2 tanks (replicates) and each tank contained 31 fish with an initial weight of 1.62±0.33 g (mean ± SD) in a completely randomized design. Fish were fed three times a day ad-libitum. Temperature and dissolved oxygen were measured once a day and salinity and pH were recorded once a week in all tanks. The study of the response to salinity stress has been validated by various researchers to investigate the physiological status and health of fish (Jelkic et al., 2014; Roohi et al., 2017; Talebian Nik and Alamdari, 2020). In the present study, in addition to studying growth performance and carcass composition (AOAC, 2000), for the first time, a combination of salinity stress, oxygen deficiency, and a sudden increase in population density was used to investigate the level of fish resistance. Two tests were used to measure the resistance of fish to death: a) salinity stress with cessation of aeration and b) salinity stress with aeration. In the first test, 10 fish from each tank were suddenly transferred to a container containing 2 liters of water with a salinity of 18 g/L and without aeration. In the second test, 10 fish from each tank were suddenly placed to a container containing 14 liters of water with a salinity of 18 g/L and with aeration. Dead fish were removed and the number of deaths per minute was recorded for until 5 hours. Results The average values of temperature, dissolved oxygen, salinity and pH were 24.6-25.5 °C, 7.4-7.6 mg/L, 2.0-2.1 g/L and 7.6-7.9, respectively. As shown in Table 5, no significant differences were observed in terms of fish weight, standard length, and condition factor between different dietary treatments (p>0.05). Table 6 shows that Se supplements had no significant effect on the survival rate during the rearing period (p>0.05). The dry matter, crude protein and ash contents of carcass did not affect (p>0.05). Feeding with 0.3 mg Availa-Se or sodium selenite per kg diet significantly reduced the crude fat content in the carcass (p<0.05). Based on Table 7, no significant differences were observed in terms of survival time after exposure to salinity stress without aeration (higher-intensity stress) (p>0.05). After salinity stress with aeration (lower-intensity stress), the use of sodium selenite significantly increased survival time (p<0.05) and although the use of Availa-Se improved this index, it had no significant effect compared to the control (p>0.05), while the use of Selstar significantly reduced survival time (p<0.05). <div aria-label="Page Break" class="cke_pagebreak" contenteditable="false" data-cke-display-name="pagebreak" data-cke-pagebreak="1" style="page-break-after:always" title="Page Break"></div>Discussion and conclusion The insignificant difference in the survival rate of the fish indicated that the living conditions were suitable for them (Hassan and Mohammad, 2023). There are conflicting reports on the effect of selenium supplementation on the growth and carcass analysis in different fish. It depends on many factors such as water quality, feed and genetic factors (Sumana et al., 2023). Selenium is absorbed more effectively in the presence of certain nutrient compounds and they affect the bioavailability of selenium (Mustafa and Omar, 2024). Selenium affects lipid, sugar and amino acid metabolism in aquatic animals (Li et al., 2023). In the present study, increasing the amount of selenium in the diet did not affect growth parameters and some biochemical carcass indices. Accordingly, higher doses of Se may be required to observe effects on growth parameters (Durigon et al., 2019) and carcass analysis. However, according to new standards, the amount of selenium supplementation in animal feed is limited (Sumana et al., 2023). Studies have shown that varying selenium doses and stress conditions even within the same fish species, affect the severity of stress responses (Mechlaoui et al., 2019). The present study showed that although fish fed a diet without selenium supplementation had good growth and a high survival rate during the rearing period compared to other fish, the amount of selenium in the control diet was not sufficient to protect the fish against stressful conditions. The level of resistance to salinity stress in common carp was higher when sodium selenite than organic selenium with the brand name Availa-Se or Selstar were consumed. In general, the use of Selstar organic selenium is not recommended and 0.3 mg/Kg selenium from sodium selenite is optimal dose in common carp diet. Conflict of interest The authors declare that they have no conflict of interest. Acknowledgement This research was conducted with the financial support of Darya Shilan Dez Company. استرس, اویلاسلنیوم, سل‌‌استار, سلنیت سدیم, ماهی Availa-Se, Fish, Selstar, Sodium selenite, Stress 73 84 http://isfj.ir/browse.php?a_code=A-10-2263-8&slc_lang=fa&sid=1 Hojjatollah Alamdari حجت اله علمداری alamdari671@yahoo.com 100319475328460041577 100319475328460041577 Yes Behbahan Khatam Alanbia University of Technology گروه شیلات، دانشکده منابع طبیعی، دانشگاه صنعتی خاتم‌‌الانبیاء‌‌ (ص) بهبهان، بهبهان، ایران Narges Bahreinipour نرگس بحرینی پور narges.bahrainipour@gmail.com 100319475328460041578 100319475328460041578 No Behbahan Khatam Alanbia University of Technology گروه شیلات، دانشکده منابع طبیعی، دانشگاه صنعتی خاتم‌‌الانبیاء‌‌ (ص) بهبهان، بهبهان، ایران