نوع مقاله : مقاله پژوهشی
نویسندگان
1 انستیتو تحقیقات بین‌المللی ماهیان خاویاری، موسسه تحقیقات علوم شیلاتی کشور، سازمان تحقیقات، آموزش و ترویج کشاورزی (AREEO)، رشت، گیلان
2 شرکت دانش بنیان زیست پالایشگر خزر
چکیده
کلیدواژه‌ها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Introduction: Polychaeta, or bristle worms, are a class of marine Annelid worms with segmented bodies. Each segment has paired fleshy appendages called parapodia, equipped with bristles known as chaetae made of chitin. Over 10,000 species are described, and polychaetes play vital ecological roles as predators and prey in their ecosystems. Polychaeta, Hediste diversicolor is one of the important live foods in fish and crustacean nutrition such as sturgeon and shrimp. This study aimed to investigate the effect of different levels of selenium nanoparticles (Se-NPs) and iron nanoparticles (Fe-NPs) on the growth and survival of H. diversicolor.
Materials and methods: 48000 Hediste worms (with an average wet weight of 37 mg) were distributed in 12 tanks (50-L volume) as a completely randomized design with four treatments and three replications (4000 worms per m2). Treatments included control (without adding nanoparticles), T1 = 50 mg/kg Fe-NPs + 0.5 mg/kg Se-NPs, T2 = 100 mg/kg Fe-NPs + 1 mg/kg Se-NPs and T3 = Fe-NPs 200 mg/kg + 2 mg/kg Se-NPs. Before starting the experiment, Hediste worms were adapted to the tank conditions for one week, and then they were fed diets containing selenium and iron nanoparticles for 12 weeks.
Results and discussion: The results indicated that increasing the amounts of selenium nanoparticles (Se-NPs) and iron nanoparticles (Fe-NPs) in the diet significantly enhanced the biomass and survival rate of Hediste worms. Specifically, as the concentrations of selenium and iron in the treatments increased, the length of L3 (the combined length of the first three segments: prostomium, peristomium, and first chaetiger) decreased significantly. T2 and T3 exhibited shorter L3 lengths compared to the control group. The highest survival rates were observed in T2 (65.5%) and T3 (66.6%), while the greatest biomass was recorded in T3 (1514.8 g/m²). Notably, Hediste worms in the control group consumed significantly more food and displayed the highest food conversion ratio (FCR). In contrast, the lowest FCR values of 0.57 and 0.54 were recorded in T2 and T3, respectively, indicating a positive effect of these nanoparticles on improving FCR.
Conclusion: The combined application of Se-NPs at a concentration of 2 mg/kg with 200 mg/kg Fe-NPs demonstrated a superior effect on the growth and survival rate of Hediste diversicolor compared to both the control diet and other treatments.
Conflicts of interest: Authors have no conflict of interest to declare for the publication of the present work.
Acknowledgments: This research was conducted as a study opportunity for members of the faculty of the Agricultural Research, Education, and Extension Organization in Society and Industry. We would like to thank the Zist Palayeshgar Khazar Company (ZPK) and the International Sturgeon Research Institute.
کلیدواژه‌ها [English]
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