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Percorrer por autor "Lebria, Arash"

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  • Evaluation of superworm (Zophobas morio) larvae meal as a fish meal substitute in juvenile stellate sturgeon (Acipenser stellatus) diets
    Publication . Lebria, Arash; Langroudi, Hadi Ershad; Pajand, Zabih Ollah; Sajjadi, Mirmasoud; Abdollahpour, Hamed
    This study aimed to evaluate the effects of dietary inclusion of superworm (Zophobas morio) larvae meal (SWM) on growth performance, hematological parameters, blood biochemical parameters, proteolytic enzyme activity, and body composition in juvenile stellate sturgeon (Acipenser stellatus). A total of 120 juvenile fish (initial body weight: 28.08 ± 0.13 g) were randomly assigned to four dietary treatments in triplicate groups. Experimental diets were formulated to replace 0% (control), 10% (SWM10), 20% (SWM20), and 30% (SWM30) of fish meal with SWM, maintaining isonitrogenous (45.27% protein) and isoenergetic (19.50 MJ/kg) profiles. Fish were hand-fed to apparent satiation three times daily over an 8-week period. Growth performance data indicated that up to 10% SWM inclusion did not significantly affect final weight, weight gain, or condition factor compared to the control (p > 0.05). However, 20% and 30% inclusion levels resulted in significantly reduced growth performance (p < 0.05). Hematological analysis showed that WBC counts were significantly higher in all SWM-fed groups (16.2–19.3 ×10 ³/mm³) compared to the control (13.9 ×10 ³/mm³), with neutrophil percentages also elevated (16.3–17.2% vs. 13.7% in the control) (p < 0.05). No significant differences were observed in RBC count, hemoglobin, hematocrit, MCV, MCH, or MCHC (p > 0.05). Biochemical results showed that triglyceride levels were significantly elevated in the SWM30 group (p < 0.05), while cholesterol levels were significantly lower compared to the control (p < 0.05). Serum glucose level remained unaffected across treatments (p > 0.05). Proteolytic enzyme analysis indicated a significant reduction in trypsin activity in fish fed the SWM30 diet (p < 0.05). Whole-body composition analysis revealed that increasing SWM inclusion significantly decreased carcass protein, moisture, and ash contents, while lipid content increased, with the highest fat level observed in the SWM30 group (p < 0.05). Overall, the findings suggest that superworm larvae meals can be included in the diet of juvenile stellate sturgeon at levels up to 10% fishmeal replacement without adverse effects on growth, hematological parameters, blood biochemistry, or proteolytic enzyme activity.
    2026-07Artigo científico Acesso aberto Ver mais
  • Size-dependent salinity tolerance in juvenile stellate sturgeon (Acipenser stellatus): physiological and histopathological responses
    Publication . Pajand, Zabih Ollah; Hosseinnia, Esmaeil; Jafari Pastaki, Naghmeh; Hallajian, Ali; Yousefi, Ayoub; Lebria, Arash; Ashori, Alireza; Abdollahpour, Hamed
    We investigated the physiological, endocrine, and histological responses of juvenile stellate sturgeon (Acipenser stellatus) to salinity challenge across four weight classes (0.89 ± 0.21, 2.01 ± 0.32, 4.84 ± 0.39, and 9.07 ± 1.47 g; mean ± S.E.) and four salinity levels (0, 4, 8, and 12 ppt) over acute to chronic exposure (3–624 h). A total of 4800 juveniles were used across four sequential experiments, with 100 ± 5 fish per tank (12 tanks per experiment). A replicated factorial design (three tanks per treatment) enabled robust assessment of ionoregulation, stress response, and tissue integrity. Plasma osmolality increased from approximately 230 to 266 mOsm kg− 1 during early exposure, followed by progressive convergence toward a narrower physiological range (≈251–284 mOsm kg− 1 ) at 624 h, indicating partial osmotic compensation. This adjustment was driven primarily by sodium, which exhibited the strongest salinity- and size-dependent response, confirming its central role in extracellular osmotic regulation. In contrast, potassium displayed pronounced size-dependent dysregulation, with markedly elevated concentrations in fish 3 g maintained values within or near the physiological range. Cortisol dynamics revealed a clear ontogenetic shift in stress responsiveness. Smaller juveniles (3 g) demonstrated more efficient recovery, with the 5–10 g group achieving ~92% recovery by 96 h, compared to only ~45% in the smallest size class. These endocrine patterns were consistent with ionoregulatory performance and further support a size-dependent transition in physiological resilience. Histopathological analysis corroborated systemic findings. Histopathological analysis using a semi-quantitative scoring system (0–4) revealed significant size- and salinity-dependent tissue alterations. Gill tissues showed lamellar fusion, epithelial lifting, hyperplasia, necrosis, and hemorrhage, with more severe lesions in smaller juveniles at intermediate to high salinities. Kidney tissues exhibited glomerular expansion, tubular degeneration and obstruction, congestion, hemorrhage, and hemosiderin deposition, with lesion severity generally decreasing with increasing body size. These histological patterns were consistent with physiological and endocrine responses and reflected greater structural resilience in larger juveniles under salinity stress. Collectively, these integrated responses identify an empirical transition zone at approximately 3 g under the tested conditions, below which juveniles exhibit limited capacity to maintain physiological homeostasis under salinity challenge. Above this threshold, fish display more effective physiological regulation, resulting in better ion balance, lower stress, and improved tissue integrity. Together, these findings provide mechanistic evidence for size-based acclimation protocols, gradual salinity transitions, and optimized release strategies to enhance survival and performance in aquaculture and stock enhancement programs.
    2026-10Artigo científico Acesso aberto Ver mais