Deadline for manuscript submissions: 30 June 2026.
This study aimed to determine the acute dietary toxicity and Maximum Allowable Concentration (MAC) of selenium (Se-NPs) and iron (Fe-NPs) nanoparticles for the ragworm (Hediste diversicolor). This worm is a critical live feed source in sturgeon aquaculture, directly influencing the health and growth of larvae and juveniles. However, the safe dietary levels of these nanoparticles for the ragworm itself, and consequently the risk of trophic transfer to sturgeon, remain unknown. Determining safe dietary levels of nanoparticles in this organism is therefore essential for ensuring the safety of the entire sturgeon feed chain. Worms were exposed to six concentrations (0, 100 μg/kg, 1, 10, 100 mg/kg, and 1 g/kg diet) of each nanoparticle for 96 h in three replicates. Throughout the experiment, aeration was provided, and worm behavior was monitored. Cumulative mortality was recorded at 24, 48, 72, and 96-h intervals. Data were recorded in Microsoft Office Excel 2019, and statistical analysis was performed using SPSS software (Version 26). Data were analyzed by Probit analysis with a 95% confidence level. The LC10, LC50, and LC90 values for Se-NPs were calculated to be 291.2, 989.8, and 1690 mg/kg, respectively. For Fe-NPs, these values were 924.3, 3300, and 5700 mg/kg, respectively. Using a standard Safety Factor (SF) of 10, the calculated MAC are 98.98 mg/kg for Se-NPs and 330.0 mg/kg for Fe-NPs. This study establishes critical toxicity thresholds for Se-NPs and Fe-NPs in ragworm. The findings provide essential data for developing safe feeding protocols in sturgeon aquaculture, helping to prevent potential nanoparticle toxicity transfer through contaminated live feed and ensuring sustainable sturgeon production.
To restore the stocks of sturgeon fish species in a depressed state, it is necessary to form broodstocks in hatchery farms. The technology of forming stocks in industrial conditions is far from perfect due to the low quality of breeders. The aim of this work was to identify the frequency of occurrence of anomalies and diseases of sturgeon internal organs using the method of ultrasound scanning and histological study. Two-dimensional black-and-white image, Doppler, elastography, and panoramic scan were used. Regular sonographic studies of abdominal organs, carried out in 2018–2025 at 20 fish farms, revealed a number of common pathologies and diseases in generative tissue: cystosis and polycystosis, fatty degeneration, underdevelopment and torsion of testes, neoplasm, hermaphroditism, sludge in the gallbladder, ascites, and others. The maximal number of individuals with disorders in the development of internal organs reached 67.9%, an average is 24.8%. Two stages of cystic degeneration of the ovaries were characterized by ultrasonic scanning. A significant increase in the number of females over 9 years old, with replacement of generative tissue with connective tissue (13.6%), was noted. The nature of ‘ink spots’ on the skin of Siberian sturgeon natural populations was studied. Malignant skin neoplasms were detected, and treatment routes were outlined.
