ALBERT

Description: Based on an agreement between Jahad Nasr Hamzeh Company as "the employer" and the Iranian Fisheries Research Organization as "the executor", a project entitled “culture of Huso huso up to 10 kg" was conducted. A total of 600 Huso huso with the average weight of 5000 g were distributed in four 50 m2 circular concrete tanks (4 diameters) with the density of 25 kg/m2 . The experimental system was equipped with aeration. Dissolved oxygen concentration was maintained at 6-7 mg/l. Fish were fed experimental diets composed of 43% protein, 22 % lipids, 16.2% carbohydrates and 22 MJ/kg energy for 12 months. At the end of the first rearing phase (365 d), fish with the mean specific growth rate (SGR) and feed conversion ratios (FCR) of 0.27 and 2.91, respectively reached a weight of 9.06 kg. The highest growth parameters and the best FCR were recorded in spring and autumn. The mean body weight increase (BWI %), specific growth rate (SGR) and feed conversion ratio (FCR) in these seasons were estimated at (0.48, 0.36 % per day), (27.4, 20.13 % during the rearing period) and 1.85 and 1.74, respectively. Results obtained from this project revealed that Huso huso is a prospective candidate for intensive culture in concrete tanks and these results can be developed in many parts of the country.

Description: Iranian Fisheries Science Research Institute

Description: Published

Description: Four experiments were conducted to study of production meat in reared beluga (Huso huso) with different diets. In the first experiment, A 19-week feeding trial was conducted to evaluate dehulled soybean meal (DHSM) as a fish meal (FM) replacer in juvenile beluga, of initial body weight 8.25 ± 0.08 g (mean ± SD) in triplicate groups, fed six isoenergetic (20.1 mJ kg-1) and isoproteic (45% crude protein) diets, resulting in 5%, 10%, 15%, 20% and 25% of fish meal protein being replaced by soybean protein. Growth performance was reduced significantly with the increasing of DHSM in the diets in the present study. In the next stage, triplicate groups of 315 fish averaging 300.25 ± 10.28 g (mean ± SD) were fed one of seven experimental diets for 14 weeks. Weight gain (WG), specific growth rate (SGR), feed effeciency (FE), protein efficiency of retio (PER) of fish fed 5%, 10% and 15% of soybean protein diets were significantly higher than those of fish fed 20%, 25% and 30% diets. Whole body protein, lipid, moisture content were unaffected among different treatments (P 〉 0.05). In the second experiment, A 2 × 4 factorial design was used to evaluate the dietary lysine and to determine the optimum dietary L-carnitine in sub-yearling beluga, reared in the indoor system. Twelve experimental diets were formulated and prepared to contain four lysine levels (0.75, 1.5, 2.25 and 4% diet) and two L-carnitine levels (300 and 600 mg/kg diet) at each lysine level. Fish averaging 23 ± 0.5 (mean±SD) were fed one of the experimental diets for 10 weeks. At the end of the experimental period, there were significant lysine and Lcarnitine effects (P 〈0.05) on growth performance and feed conversation ratio (FCR). These results may indicate that, weight gain (WG), FCR and protein efficiency ratio (PER) in fish fed diet containing 3% lysine and 600 mg L-carnitine/kg diet were significantly higher than those of fish fed control diet (P 〈 0.05). There were no significan dietary lysine and L-carnitine effects on glucose, cholesterol and haemoglobin (Hb) concentration, of fish fed different levels of lysine with 300 mg L-carnitine/kg diet, however, Hb concentration in fish fed diet containing 2.25% lysine and 600 mg L-carnitine/kg diet were significantly higher than those of fish fed control diet (P 〈 0.05). These results may indicate that the optimum lysine and the L-carnitine levels could be 2.25-3% and 600 mg L-carnitine, respectively in begga (8-300 4g), based on growth performance, feed utilization and hematological parameters. In the thired experiment, a study was conducted to evaluate the effects of dietary betafine and metionine interaction on the growth, feed efficiency, carcass composition and hematological index in juvenile beluga. Thirteen diets were formulated to contain four dietary metionine levels (0.5, 1, 1.5 and 2%), betafine (0.5, 1, 1.5 and 2%) with equal ratio of metionine and betafine (0.5: 0.5, 1: 1, 1.5: 1.5 and 2: 2% diet) were fed to juvenile beluga (23± 0.5 g) in triplicate groups for 12 weeks in a indoor system. The results showed that no significant (P〉 0.05) differences were found in growth performance and feed utilization among the dietary betafine and metionine concentrations in beluga. Hb concentration of fish fed control, 1 and 1.5% metionine were significantly higher than those of fish fed the other diets. FCR of fish was significantly improved by dietary metionine and betafine. FCR was lower (P 〈 0.05) in fish fed equal ratio of metionine and betafine (2: 2) diets than those in fish fed control diet. Based on above results, it is recommended that the diet for juvenile beluga, Huso huso (8-300g), should contain equal ratio of metionine and betafine (1.5: 1.5) diet, corresponding to 5.95 g/100 g of dietary protein for optimum growth, efficient feed utilization and whole-body protein content. A 17-week feeding trial was carried out to evaluate the effects of dietary L-carnitine level in beluga, Huso huso. A total of fish averaging 1247 ± 15.6 g (mean ± SD) were randomly distributed into 18 fibreglass tanks, and each tank holding 10 fish was then randomly assigned to one of three replicates of six diets with 50, 150, 350, 650, 950 and 1250 mg L-carnitine kg-1 diet. At the end of 17 weeks of feeding trial, average weight gain (WG), feed efficiency (FE), protein efficiency ratio (PER) and condition factor (CF) of fish fed 350 mg kg-1 diet were significantly (P 〈 0.05) higher than those of fish fed 50, 150, 950 and 1250 mg kg-1 diets. WG, FE, PER and CF of beluga fed 650 mg kg-1 diet were also significantly higher than those of fish fed 50, 950 and 1250 mg kg-1 diets. Whole body and muscle protein were significantly improved by the elevation of dietary L-carnitine level up to 350 mg kg-1. Liver superoxide dismutase and glutathione peroxidase activities of fish fed 350 and 650 mg kg _1 diets were significantly higher than those of fish fed 50, 950 and 1250 mg kg-1 diets. The dietary Lcarnitine level of 350–650 mg kg-1 diet could improve growth performance, feed utilization, protein-sparing effects of lipid, antioxidant defence system and reproductive success. Polynomial regression of WG suggested that the optimum dietary L-carnitine level was 480 mg kg-1 diet. Therefore, these results may indicate that the optimum dietary L-carnitine could be higher than 350 but 〈650 mg kg-1 diet in beluga reared in intensive culture conditions.

Description: Iranian Fisheries Science Research Institute

Description: Published

Description: This study was carried out on 16 Sturgeon spawner(6 ship and 10 persian sturgeon) which were operated in shahid Dr. beheshti Rearing and Propagation Complex during 2001, 2002 and 2003. surgery performed on 16 spawners (6 ship sturgeon and 10 persian sturgeon). operation fulfilled in 3 ways: 1- without anesthesia 2- anesthesia by injection of Chanazin 2%(4 to 10 mg for per kilogram of fish body weight) 3- anesthesia by replacing fish in clove powder solution. In the surgery operation without anesthesia, the fish maintained by three persons and the eggs removed. In the case of applying anesthesia, 2% Chanazin, with commercial name Rompun(20 mg/ml), 4- 10 mg for per kilogram of body weight injected, but the rate of clove Powder application was 150 200 mg/l.surgery carried out by Kosarva method(making slight cut on Ventral area stitching). The cut length was 6-8 cm. The cut site stitched by Kapron unabsorbable thread and single knot with 6 to 7 mm distance.The mean weight of female spawners of ship(Acipenser nudiventris) was 35.3 ± 8.3 kg(n=6) which 3.9 ± 0.89 kg caviar, removed on average(11% of total body weight). The mean weight of female spawners in Persian sturgeon(Acipenser persicus) was 23.6 ± 3.2 kg(n=10) that the mean rate of caviar removed was 2.7 ± 0.62 kg(11.4% of total body weight). Investigation on reared spawner of ship(Acipenser nudiventris, n=16) and Persian sturgeon (Acipenser persicus,n=60) without surgical operation showed that the average body weight of spawners was 43.7 ± 8.8 kg and 28.9 ± 6.4 kg and the mean rate of caviar removal was6.4 ± 1.7 kg (15.7% of total body weight) and 4.4 ± 1.3 kg (15.4% of total body weight) respectively. During 2001, surgical operation performed on 8 spawners(5 ship and 3 persian sturgeon) which one Persian sturgeon and 2 ship after one day, one ship after 3 days and two ship after 32 days and 105 days and 2 persian sturgeon after 91 and 136 days were died. During 2002, totally five Persian sturgeon were operated which all of them died after 46,116,130,132 and 157 days. During 2003, 3 spawners(2 persian sturgeon and one ship) were operated which two Persian sturgeon died after 23 and 59 days and one ship spawnerdied after 72 days. This mortality can be due to not feeding of formulated food and even live food by the wild spawners after surgery. Also, other factors can be mentioned, such as existence of otter in the ponds with spawners are kept, breaking of swim bladder during egg sampling in catch stations & hatcheries small area for maintaining spawners after surgery and not tolerating of surgical operation by some spawners. It should be mentioned that surgery point has been fully improved in the spawners that survived more than 40 days after surgery. The results of the study indicated that removal of caviar from wild spawners is possible, but maintaining them in freshwater to remove caviar again, can be problematic. So, the surgery for caviar removal & removing of caviar for second time in following years should be carried out only on reared spawners.

Description: Iranian Fisheries Science Research Institute

Description: Published

Description: The osmoregulatory system was studied in wild adult and reared juvenile Persian sturgeon, Acipenser persicus. The mean osmolarity in blood serum of specimens from the Caspian Sea, estuary, the Kouraneski pools and the rearing tanks were 305.3±14.3, 308.7±25.8, 265.0±19.1 and 259.3±8.8 mosmol/L, respectively; the mean concentrations of Na+ were 151.2±6.3, 152.2±8.4, 142.5±5.9 and 131.4±4.1 meq/L whereas mean concentrations of K+ were 2.7±0.9, 3.6±0.9, 3.1±0.5 and 2.6±0.5meq/L, respectively. The concentrations for Mg++ ion in fish of the same four origins were 1.5±0.2; 1.5±0.3, 0.8±0.2 and 0.7±0.2 meq/L, and those of Ca++ were 2.31±0.51, 2.61±0.51, 1.85±0.58 and 1.46±0.43, respectively. The Pearson's correlation coefficient and regression equation indicated that Mg++(r =0.38) and Na+ (r=0.41) were effective ions for determination of blood serum osmotic pressure in A. persicus in brackish water and freshwater. This study also showed that blood serum osmotic pressure was independent of sex.

Description: Published

Description: High mortality of beluga prelarvae (Huso huso) occurs in hatcheries and this appears to be linked to various abnormalities. Hence, this study was conducted to compare the body shape of alive and dead beluga prelarvae (5DPH) and to find the patterns of deformities among losses using geometric morphometric method. This method was applied to extract shape data as landmark’s Cartesian coordinates. Specimens were photographed using digital camera and the landmarks put on two-dimensional images using tpsDig2. Landmark data after GPA (Generalized Procrustes Analysis) analyzed using PCA and DFA. Results showed significant differences between alive and dead prelarvae shapes. In addition, various pattern of deformities found in the operculum, yolk sac and caudal peduncle parts. Future studies are suggested on larvae and juvenile stage.

Description: Published

Description: The Persian Sturgeon, Acipenser persicus is the most important sturgeon species in the southern part of the Caspian Sea and it provides 51% of Iran's caviar production. We were used five different age groups of the larvae (7, 17, 22, 28 and 33 days after yolk absorption) in 3 replicates. The larvae were all transferred at the same time to 27 liter aquarium holding 15 liter of water at different salinities (0.5, 7 and 9 ppt) and were provided with continuous aeration. Analysis of data showed that during early stages of life, age is an important factor for development of osmoregulatory organs. However, in later stages, weight and length play a vital role in this regard. The present study reveals that during post hatch and active feeding, in favorable environmental and rearing condition A. persicus fingerlings could be released into rivers and estuaries in Guilan province at an age of 33-35 days after yolk sac absorption and when they attain weight of 1.8-2.4g and length of 6.2-7.5cm.

Description: Published

Description: Levels of two main steroid hormones in gonads, 17-B Stradiol (E2) and testosterone (T) were compared in males and females of Persian sturgeon at the start of autumnal migration to spawning rivers. Hormone levels were also studied for likely relationship with different stages of sexual maturity. The results showed that levels of T and E2 in females at the stage four of sexual maturity is significantly higher than the individuals with immature gonads (ovary in stages 2 and 3). We measured 11.81±2.86Ong/ml and 7±1.15ng/ml of T and E2 in mature females compared to 0.2±0.09ng/ml and 0.736±0.161ng/ml of T and E2 in immature females. Levels of the two hormones in males at different stages of sexual maturity showed that only testosterone was significantly different in mature and immature sturgeons (0.50±0.144 ng/ml and al 4.3 I 25±3.121ng/ml in mature and immature males, respectively) (P=0.04). In males and females with higher sexual maturity, differences between the two hormones were significant (T and E2 levels in females and males were 11.81±2.860ng/ml, 7±1.15ng/ml and 0.50±0.144ng/ml, 0.7023±0/212ng/ml, respectively). However, in immature fish of both sexes, only males showed significantly higher T levels (14.312513.121ng/ml in comparison with 0.2±0.09ng/ml). Disregarding the sexual maturity stages, we found significantly different levels of E2 in both sexes (4.779±1.827ng/ml in females and 0.709±0.121ng/ml in males) (P=0.00). Statistical analyses indicated no correlation between fish age and levels of steroid hormones of the fish (at 90% confidence level).

Description: Published

Description: Reciprocal crosses betvveen Beluga and Persian Sturgeon in four treatments and three replications were conducted and reproduction metrics including number of eggs per gram, percentage of fertilization, and survival rate were assessed. Also, we measured 32 morphomeiric and meristic attributes of brood stocks, hybrids and controls. To compare the growth rate of hybrids and controls, fingerlings were grown for 18 months in 2000 liter fiberglass tanks and fed by pellets. During rearing period, 17 samples were taken in 15-30 days interval and total weight and length of the specimens were measured. Average weight and length, standard deviation, analysis of variance, Duncan test and Heterosis were calculated. We found a significant difference (13〈0.003) between numbers of eggs of Beluga (controls) in comparison with hybrid (6Beluga x Persian sturgeon) and between Persian sturgeon's eggs with hybrids (Y Beluga x dPersian sturgeon). However, no significant differences were found (1)?0.001) between controls and treatments in terms of fertilization rate (in stage 4 and 35), number and mortality rate of larvae during active feeding and final stages. Hybrid and control fingerlings showed different growth performances. After an 18 months rearing period, the highest growth was found in Beluga (975±10 grams), with hybrid of female i al Beluga and male Persian sturgeon coming next (840±143 grams), hybrid of male Beluga with female Persian sturgeon being the third (681.152$1 grams). The slowest growth rate was seen in control Persian sturgeon with an average growth of 535.15±131 grams. Daily growth rate of hybrids produced from crossing of female Beluga with male Persian sturgeon was higher than control Beluga during second and third rearing period each taking six months. We observed significant differences (p〈0.05) in 31 morphometric and meristic parameters from a total of 32 attributes. The percentage of heterosis was variable, being -73.76 in early growth period and 0.79 at the final rearing stage with an average heterosis of -32.69. The hybrid produced from female Beluga and male Persian Sturgeon showed a very good o growth performance. However, with the inadequacy of female Beluga in the Caspian Sea and the priority of restocking Beluga, it is suggested that the hybrid production be conducted using male • Beluga and female Persian Sturgeon.

Description: Published

Description: A 17-week feeding trial was carried out to evaluate the effects of dietary L-carnitine level in beluga, Huso huso. A total of fish averaging 1247 ± 15.6 g (mean ± SD) were randomly distributed into 21 fibreglass tanks, and each tank holding 10 fish was then randomly assigned to one of three replicates of seven diets with 50, 150, 350, 650, 950 and 1250 mg L-carnitine kg-1 diet or control diet (Biomar). At the end of 17 weeks of feeding trial, average weight gain (WG), feed efficiency (FE), protein efficiency ratio (PER) and condition factor (CF) of fish fed 350 mg kg-1 diet were significantly (P 〈 0.05) higher than those of fish fed 50, 150, 950 and 1250 mg kg-1 diets. WG, FE, PER and CF of beluga fed 650 mg kg-1 diet or control diet (Biomar) were also significantly higher than those of fish fed 50, 950 and 1250 mg kg-1 diets. Whole body and muscle protein were significantly improved by the elevation of dietary L-carnitine level up to 350 mg kg-1. Liver superoxide dismutase and glutathione peroxidase activities of fish fed 350 and 650 mg kg-1 diets were significantly higher than those of fish fed other diets. The dietary L-carnitine level of 350mg kg-1 diet could improve growth performance, feed utilization, protein-sparing effects of lipid, immune response, antioxidant defence system and reproductive success.

Description: Published

Description: Histological studies are of the most adequate way to determine the physiological condition of fish organs. The present research was carried out in order to conduct a qualitative evaluation of the growth and development of the reproductive system of three sturgeon species (Acipenser persicus, Acipenser gueldenstaedti, and Huso huso). In this evaluation two histological approaches, gonadectomy and biopsy, were employed. The studied sturgeons consisted of 58 one, two and six years old reared juveniles. Some 60% of the one-year-old Huso huso were of unknown sex, 20% were previtellogic females and 20% of the males were in the early stage of spermatogenesis. On the other hand 50% of the one-year-old Acipenser persicus were also of unknown sex, 30% premature females and 20% premature males. Some 30% of two-year-old Huso huso were of unknown sex, 40% premature females and 10% of the females were in stage I of sexual maturity and 10% were premature males. Among the six-year-old specimens, 60% of the Acipenser persicus were females in stage II of sexual maturity, 20% were males between stage II and III of sexual maturity and 20% were of unknown sex, while in the same age group 50% ofAcipenser gueldenstaedti were males in stage II of sexual maturity and 50% were females in stage II(semi lipid) of sexual maturity. The results of the study indicated that 28.75% were females were in stage II of the sexual maturity, 14.28% were female in stage II (lipid) of sexual maturity, 14.28% females in stage I of sexual maturity, 28.75% males between stage II and III of sexual maturity and 14.28% were males in stage IV of sexual maturity. The conducted study on the juvenile sturgeon confirmed that the growth process of the gonads occurred as it would have happened under natural circumstances. Occurrence of six-year-old Huso huso in stage IV of sexual maturity indicated that the rearing conditions in the fiberglass tanks and earthen ponds have been favorable and on the other hand no extra surplus energy has been used.

Description: Published