Summary The effect of starvation and subsequent re‐feeding to satiation on compensatory growth performance, insulin and blood serum values were investigated in juvenile Persian sturgeon (Acipencer persicus) with an average weight 108.04 ± 0.28 g (mean ± SEM) and in the same rearing condition over an 8‐week period. Sturgeons were allocated to one of five feeding treatments: controls (C, continuous feeding), W1 (1 week starvation), W2 (2 weeks starvation), W3 (3 weeks starvation) and W4 (4 weeks starvation), followed by a single 4 weeks of re‐feeding to satiation. Changes in growth performance and blood serum indices were examined at the end of weeks 4 and 8. Body weight, specific growth rate (SGR), condition factor (CF) and weight gain were determined to have significantly decreased during starvation. Fish starved for 1 week reached the same weight as the control fish after re‐feeding for 4 weeks, indicating that complete compensatory growth occurred. Although the specific growth rate in W2, W3 and W4 fish was greater than that in the control fish after re‐feeding, W2, W3 and W4 fish did not reach the same body weight as control fish at the end of re‐feeding period, and showed partial compensation only. Blood plasma, glucose and insulin concentrations did not change significantly during starvation and re‐feeding (P > 0.05). This suggests that sturgeon are able to maintain glycaemia during starvation, probably due to their non‐carbohydrate dietary source. Plasma total lipid and triglyceride levels increased in starvation treatments, whereas the increases were significant only in W3 treatment (P < 0.05). After a 4‐week re‐feeding period, their levels decreased in comparison to the starvation periods. Increases in plasma total lipid and triglyceride levels appear to be due to their roles as preferred nutrients for mobilization in Persian sturgeon and the magnitude and duration of compensatory growth depended on the length of food deprivation.

A 44‐day rearing trial was conducted to examine the enrichment of Artemia urmiana nauplii with vitamin E and highly unsaturated fatty acid (HUFA) and its effects on the growth performance, survival and stress resistance of great sturgeon, Huso huso, larvae. Cod liver oil (EPA 18% and DHA 12%) and α‐tocopherol acetate were used as lipid and vitamin E sources. Beluga larvae at the first exogenous feeding with 69±5.9 mg body weight were randomly distributed into four treatments and three tanks were assigned to each diet. The test treatments were as follows: larvae fed with HUFA+20% and HUFA+50% (w/w) vitamin E‐enriched Artemia nauplii (E1 and E2 groups, respectively), HUFA without vitamin E (HUFA group) and non‐enriched Artemia (control group). All treatments fed non‐enriched Artemia for the initial 5 days after first feeding and then fed enriched Artemia for 7 days. After the period of enrichment, larvae were fed with daphnia from the 13th to the 40th day. At day 40, submersion in salt water (6 ppt for 4 days and 12 ppt for 2 days) and warm water (33 °C for 2 days) was performed to evaluate larvae resistance to salinity and temperature stress. Final weight, daily growth rate, specific growth rate and weight gain were higher in beluga fed with enriched Artemia. The highest growth rates were observed in E1, whereas survival was not significantly different between groups. Use of vitamin E and HUFA significantly increased fish resistance to a salinity of 12 ppt and the lowest stress resistance was observed in the control group. Stress tolerance was not significantly different at 6 ppt and 33 °C between groups. There was no comparable difference in the haematocrit index under stress conditions. These results indicated that the enrichment of Artemia with essential fatty acids and vitamin E can affect some growth and stress tolerance factors in great sturgeon, Huso huso, larvae.

Yeganeh S., Shabanpour B., Hosseini H., Imanpour M.R., Shabani A. (2012) Chemical composition and fatty acid profile of fillets from farmed and wild common carp were assessed in the course of four seasons. Ten wild and ten0 farmed fish were collected in the middle month of each season (except summer due to unavailability of wild fish) during the year. Lipid and protein contents of the samples decreased from summer to spring (protein: 17.6 ± 0.3-15.9 ± 1.6; 18.2 ± 0.1-17.9 ± 1.4%, in the farmed and wild carp samples, lipid (5.1 ± 0.2-1.5 ± 0.5; 3.8 ± 0.6-2.8 ± 0.9%, respectively; p > 0.05), moisture content of both samples increased in this period (76.7 ± 1.4-81.4 ± 0.4, 75.5 ± 0.6-78.5 ± 0.2 in the farmed and wild carp, respectively). Protein content of wild carp fillet was higher (17.7 ± 0.8% protein vs. and 16.2 ± 1.2%) and moisture content was lower than those of the farmed counterparts (77.65 ± 0.6 vs. and 79.3 ± 0.1, p < 0.05). In all seasons, MUFA were higher than SFA and also the PUFA. In the wild carp fillet, PUFA was higher than SFA in winter and spring but in the farmed carp it was higher in all seasons except the spring. Palmitic, oleic, and DHA were the major SFA, MUFA, and PUFA in the wild carp fillet, respectively. In the farmed carp fillet, the major SFA and MUFA were similar to those in the wild one but linoleic acid was the major PUFA in all seasons. ω-3/ω-6 PUFA ratios in the wild carp fillet were higher than in the farmed counterparts.

No abstract

This study aimed to assess the efficacy of BioPlus 2B, a probiotic containing Bacillus licheniformis and B. subtilis and Ferroin solution on growth performance, body composition and haematological parameters in kutum, Rutilus frisii kutum, fry. The fish were fed dry pellets containing various ratios of probiotics and Ferroin for 60 days after absorption of the yolk sac. At the end of the trial, growth indices (final weight, weight gain, specific growth rate, daily growth rate, food conversion ratio and condition factor), body composition (crude protein, crude lipid, ash and moisture) and haematological parameters [haematocrit (Hct), haemoglobin (Hb), red blood cells (RBC), white blood cells (WBC), neutrophils (NEUTR), lymphocytes (LYM), mean cell volume (MCV), mean cell haemoglobin (MCH) and mean cell haemoglobin concentration (MCHC)] were assessed. Regarding body composition, total protein levels were higher, and ash, moisture and lipid levels were lower in fish receiving the probiotic and Ferroin treatments compared with the control group (P < 0.05). Fish receiving diets supplemented with probiotics and Ferroin solution showed significantly better growth than those fed the basal diet (control). RBC, Hct, Hb, MCV, MCH and LYM were all highest in fish fed probiotic (1.6 × 10(9) CFU/g dry pellet) + Ferroin solution (7 mg/kg dry pellet) + dry pellets. These results indicate that the combination of probiotic and Ferroin solution represents an effective dietary supplement for improving carcass quality, growth performance and haematological parameters in kutum fry.