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.

The spermatozoa of oviparous fish, such as feral carp (Cyprinus carpio), are immotile in the presence of semen plasma or isotonic solutions, and to obtain good motility, they must be diluted with suitable medium. The objective of this study was to identify the best activating solution for feral carp sperm. Sperm motilities were compared in the new activating solution (a): (50 mM NaCl, 30 mM KCl, 30 mM Tris, pH = 8.5) and activating solution (b): (50 mM NaCl, 40 mM KCl, 30 mM Tris, pH = 8.5) based on effect of pH with everyone of Na ? and K ? ions versus four other activating solutions Billard's saline solution, Poupard's saline solution, distilled water and hatchery water that is routinely used for extending carp semen. Our results showed that maximum total motility period and percentage of motile sperm were seen in selected saline solution (a). The present study describes an activating solution that prolongs feral carp sperm motility.

The anaethetic effects of 2-phenoxyethanol (2-PE) on possible primary (cortisol level) and secondary (hematological indices and glucose level) stress responses were studied in Persian sturgeon (Acipenser persicus). Fish were first exposed to 0.1, 0.3, 0.5, 0.7, 0.9 and 1.1 ml L À1 2-PE, and the time to induction (deep anaethesia) and recovery were measured. At a concentration of 0.1 ml L À1 , 2-PE failed to induce deep anaethesia in fish, whereas at concentrations of 0.7, 0.9 and 1.1 ml L À1 all fish were anaethetized within 3 min of exposure. For assessing possible stress effects caused by effective concentrations of 2-PE, the hematological indices, serum cortisol and glucose were determined in the deeply anaethetized fish as stress indicators. The 2-PE exposure resulted in significant increases in red blood cell (RBC) values at 0.3 and 0.5 ml L À1 ; parallel increases in hemoglobin values were also observed at these concentrations (P < 0.01). Moreover, a lower concentration of 2-PE (0.3 ml L À1 ) caused a significant increase in hematocrit values (P < 0.05). Among the hematological indices, mean corpuscular volume (MCV) values decreased at 0.5 ml L À1 when compared with the control and other groups (P < 0.05). Serum cortisol level was elevated at 0.3, 0.5 and 0.7 concentrations of 2-PE (P < 0.01). The glucose level followed a trend similar to that observed for cortisol. The outcome of these experiments shows that 2-PE at a concentration of 0.9 ml L À1 is a suitable anaesthetic for Persian sturgeon. This study demonstrates that rapid induction of deep anaethesia with a relatively high concentration of 2-PE (0.9 and 1.1 ml L À1 ) was associated with the lowest effects on signs of physiological stress in Persian sturgeon.U.S.

This study was carried out to examine the effect of Artemia urmiana nauplii enriched with HUFA, and vitamins C and E on stress tolerance, hematocrit, and biochemical parameters of great sturgeon, Huso huso juveniles. Cod liver oil (EPA 18% and DHA 12%), ascorbyl-6-palmitate and alpha-tocopherol acetate were used as lipid, and vitamin C and E sources, respectively. Beluga juveniles at the stage of first feeding (69.7 +/- 5.9 mg body weight) were randomly divided into five treatments and three tanks were assigned to each diet. All fish groups were fed non-enriched Artemia for the initial 5 days and then fed enriched Artemia for 7 days. Juveniles were fed with Artemia enriched with HUFA + 20% vitamin C (C group); HUFA + 20% vitamin E-enriched Artemia nauplii (E group); HUFA + 20% vitamin C + 20% vitamin E (C and E group); HUFA without vitamins (HUFA) and non-enriched Artemia (control). After the period of enrichment, Juveniles were fed with Daphnia sp. from the 13th to the 40th day. At day 40, the fish were transferred directly from fresh water (0.5 ppt) to brackish water (6 ppt for 4 days and 12 ppt for 2 days) and warm water (from 27 to 33 degrees C) to evaluate juvenile resistance to salinity and thermal shocks. Moreover, all treatments were separately exposed to freshwater in tanks with the same capacity as used for osmotic and thermal tests (as fresh water control). The addition of vitamins C, E, and C + E to HUFA significantly increased fish resistance to 12 ppt salinity and temperature stress tests, whereas survival was not significantly different among challenges at 6 ppt. There was no significant difference in the hematocrit index under stress conditions. Enrichment had significant influence on plasma Na(+) level in the C group on the 4th day at 6 ppt. Na(+) and Ca(2+) concentrations in C, E, and C and E groups on the 1st day at 12 ppt, and Ca(2+) level in E group on the 2nd day at 12 ppt were lower than the other groups. The glucose level in the C and C and E groups was lower than the other treatments on the 1st day at 12 ppt and the 2nd day at 33 degrees C. Regardless of Artemia enrichment, plasma ions (Na(+), K(+), Ca(2+), and Mg(2+)) and glucose concentrations in fish exposed to salinity stress tests were higher than fish in fresh water. Glucose concentration in plasma also increased after 2 days at 33 degrees C. Although most of our results were not significantly different, the use of vitamins C, E, and HUFA in Artemia enrichment can improve Juveniles tolerance under stress conditions, and regardless of enrichment, these data show that beluga juveniles are partly sensitive to high salinity and temperature.