Mahmoud Mohseni

This study investigated how partially replacing fishmeal (FM) with silkworm pupae (SWPs) ( Bombyx mori ) and yellow mealworm (MW) larvae ( Tenebrio molitor ) affects the growth, health, and metabolism of Siberian sturgeon ( Acipenser baeri ). Four experimental diets were tested: a control with 60% FM and no insect meal, 45% FM with 15% MW, 45% FM with 15% SWPs, and a combined diet containing 45% FM plus both insect proteins: 7.5% MW, as well as 7.5% SWPs (SMW). Fish were reared under controlled conditions, including water temperature 18 ± 1°C, dissolved oxygen 8.5–9.3 mg L ⁻¹ , pH 7.6, and a fixed feeding regime. Sturgeon fed MW and SMW diets showed significantly improved growth, higher final weight, better specific growth rate (SGR), and more efficient protein utilization, along with a lower feed conversion ratio (FCR) compared to the control. Sturgeon fed MW and SMW diets showed significantly improved growth, higher final weight, better SGR, and more efficient protein utilization, along with a lower FCR compared to the control. Digestive enzyme activities (amylase [AMS], protease, lipase [LP]) and key serum metabolites—including protein, albumin, cholesterol, triglycerides, and glucose—were elevated in insect‐fed groups. Immune and antioxidant defenses, such as lysozyme, immunoglobulin M (IgM), glutathione peroxidase (GPX), and superoxide dismutase (SOD), were enhanced, particularly in the SMW and MW treatments, while oxidative stress markers (malondialdehyde [MDA]) were favorably modulated. Gene expression analysis revealed upregulation of growth‐related (growth hormone [GH], IGF1), protein metabolism (target of rapamycin [TOR]), lipid metabolism (Apolipoprotein [ApoE]), and immune genes (interleukin‐1 [IL‐1]), with the strongest response in the combined SMW diet. Overall, partially replacing FM with insect meals, especially the MW and SWP combination, effectively supports growth, metabolism, immune function, and antioxidant capacity in Siberian sturgeon. These findings highlight the promise of insect‐based proteins as a sustainable and effective alternative in Siberian sturgeon aquaculture.

Six different feeding regimes (FR) were tested from 7 to 38 days post hatching (dph). Five thousand four hundred larvae (7 dph, 0.048 g) were randomly stocked in 18 fiberglass tanks contained 100 L fresh water (300 larvae per each tank). In larvae fed with FR-B, includes Artemia nauplii (AN) + Artemia biomass (AB) + microdiet (MD), the body weight (BW) at the end of trail (38 dph) similar the FR-D (AN + CHL + AB + MD), and E (AN + CHL + AB), was at high level. Survival rate was higher in larvae fed FR-A includes AN + chironomid larvae (CHL) + MD, but had a lower BW ( ). Moderate BW and survival rate were detected in larvae fed FR-C (AN + DP + MD). Larvae fed only MD (FR-F), had the lowest survival and the highest BW ( ). Different FR had a significant effect on crude protein (CP), crude fat (CF), ash, and dry weight ( ). The larvae fed FR-C and D had the highest CP ( ). The highest CF and ash in larvae were detected in FR-F and C, respectively ( ). Larvae from FR-A and B had higher levels of n−3 long chain polyunsaturated fatty acids in comparison with others FR ( ). The use of AB and CHL can increased the weight and survival rate of larvae, respectively. At the end of trail, the activity of pepsin, trypsin, lipase and α-amylase enzyme levels were lower in FR-B and F than others FR. Totally, by using a combination of AN + CHL + AB + MD had better results than others and ordered to H. huso larvae feeding. Using MD alone, can cause lesser development of the digestive system and little attractiveness, therefore it can cause starvation, and the empty digestive tract of larvae.

Thiamine is a crucial nutrient in larval stage of fish, and thus, the present study aimed at evaluating the effects of dietary thiamine supplementation on survival, growth performance, and biochemical parameters of beluga, Huso huso, larvae. The fish larvae (50 ± 4.5 mg) were fed diets containing 0 (control), 5, 10, and 20 mg/kg thiamine for 26 days from 18 days after hatching to 44 days after hatching. Thiamine significantly increased the larvae survival, growth rate, digestive enzymes activity, and whole body protein and ash but decreased the whole body lipid and moisture ). Also, alanine amino transferase (ALT) and alkaline phosphatase (ALP) were decreased significantly in thiamine-treated groups ( ). The highest survival and whole body ash were observed in 20 mg/kg thiamine treatment; the highest whole body protein and lipase activity were observed in 10 mg/kg thiamine treatment. The highest growth rate, amylase, and lowest whole body lipid, alanine amino transferase (ALT), and alkaline phosphatase (ALP) were observed in 10 and 20 mg/kg thiamine treatments. All thiamine-treated fish exhibited similar pepsin and chymotrypsin activities, all above the control fish. There were no significant effects of dietary thiamine supplementation on trypsin, whole body lysozyme, alternative complement (ACH50), lactate dehydrogenase (LDH) activities, and IgM levels. According to the results, 10–20 mg/kg dietary thiamine supplementation can increase the performance of beluga larvae by improving the health of liver and the activity of digestive system.

The present study was to evaluate the effect of soybean lecithin on some immunological parameters (Lysozyme, ACH50 and Total antibody), hematological and serological parameters, and liver antioxidant enzymes activity of Salmo trutta caspius. For this purpose, 90 fish (350g ± 10) were randomly divided into three treatments with three respective ...