Erfan Shahkar

Effects of Salinity Changes on Hematological Responses in Juvenile Ship Sturgeon Acipenser nudiventris

A 10-day trial was conducted to evaluate the salinity tolerance and hematological responses of juvenile ship sturgeon Acipenser nudiventris under different salinity levels. A total of 240 fish averaging 6.2 ± 0.13 g (mean ± SD) were randomly distributed into 12 tanks in groups of 20, and each tank was then randomly assigned to one of three replicates of four different salinities at 0, 4, 8 and 12‰. At the end of 10 days of experimental period, plasma protein value of fish exposed to 0‰ and 4‰ salinities was signifi cantly higher than those of fish exposed to 8‰ and 12‰ salinities ( P < 0.05). Significantly higher values for plasma cortisol and glucose were obtained in fish exposed to 12‰ salinity compared to the fish exposed to 0‰ and 4‰ salinities ( P < 0.05). Plasma potassium and sodium values increased significantly by increment of salinity levels ( P < 0.05). Therefore, these results indicated that in natural environments, juvenile ship sturgeon, A. nudiventris in migratory populations could be able to migrate and adjust successfully into brackish water with a salinity of up to 8‰ without any short-term hematological stress responses.

Evaluation of dietary soybean meal as fish meal replacer for juvenile whiteleg shrimp, Litopenaeus vannamei reared in biofloc system

Different levels of dietary soybean meal (SBM) as a fish meal (FM) replacer, with and without amino acid supplementation, for whiteleg shrimp, Litopenaeus vannamei reared in the biofloc system was examined in eight weeks of feeding trial. Eight experimental diets consisted of a basal diet with 0% FM replacement by SBM provided in clear sea water without biofloc system (S0SW), four diets replacing FM at 0% (S0), 33% (S33), 67% (S67) and 100% (S100) by SBM, and three diets replacing FM at 33% (S33A), 67% (S67A) and 100% (S100A) by SBM supplemented with amino acids (methionine and lysine) in the seawater biofloc system. Results of water quality analyses showed significantly lower total suspended solids and nitrate for S0SW group than all other treatments. Diets S0 and S33A resulted in higher weight gain and specific growth rate among all groups, with no significant differences with S33 group. In addition, whole-body protein and amino acid compositions of shrimp fed S0SW were lower than most biofloc groups. Haemolymph parameters showed significant differences in total protein, cholesterol and triglyceride between groups S0 and S0SW. Also, superoxide dismutase activity showed a decreasing trend with increasing replacement level. In conclusion, based on these results, SBM could replace up to 33% of FM with or without amino acid supplementation in juvenile whiteleg shrimp diets reared in the biofloc system.

Effects of dietary Macsumsuk® supplementation on growth performance, haematological parameters, disease resistance and body composition of juvenile Nile tilapia, Oreochromis niloticus L.

An eight-week feeding trial was conducted to evaluate the effects of dietary Macsumsuk® supplementation on growth performance, haematological parameters, disease resistance and body composition of juvenile Nile tilapia, Oreochromis niloticus. A total of 375 fish averaging 1.0 ± 0.05 g (mean ± SD) were randomly distributed into 15 tanks in groups of 25, and each tank was then randomly assigned to one of three replicates of five diets containing 0(M0), 0.3(M0.3), 0.6(M0.6), 1.2(M1.2) and 2.4(M2.4)% dietary Macsumsuk®. At the end of eight weeks of feeding trial, average weight gain (WG), specific growth rate (SGR), feed efficiency (FE) and protein efficiency ratio (PER) of fish fed M1.2 diet were significantly higher than those fed M0 diet (P < 0.05). Significantly higher values for haematological parameters, such as red blood cell (RBC), haemoglobin (Hb) and haematocrit (HCT), were obtained in fish fed M0.6 diet compared to the fish offered M2.4 diet. Although an analysis of variance (ANOVA) test suggested that the optimum level of dietary Macsumsuk® in juvenile Nile tilapia, O. niloticus, could be 1.2%, broken-line analysis of WG indicated a level of 0.803% when Macsumsuk® is used as the dietary feed additive.

EFFECTS OF VITAMIN E DEFICIENCY ON DIETARY VITAMIN C REQUIREMENT IN SIBERIAN STURGEON (Acipenser baerii)

هديکچ سرزب ی سرا رَظٌه ِب زضاح ی با ی ييهاتیٍ لباقته تازثا C ٍ E اّ صخاض ،ِیذغت ییاراك ،ذضر دزکلوع زب ی ًَخ ی ، ب ي ضَ ي و ي ا یی ، شًآ ی ن اّ ی ذبك ی ّاوسات ِچب یٌویا نتسيس ٍ ی س ي زب ی ( Acipenser baeri ) ضرٍزپ ی ، لیرَتكاف حزط بلاق رد 5 × 2 حازط ی ٍ دزگ ازجا ی ذ زّ ییاذغ ُزيج ُد . ی ک س اب ِ ييهاتیٍ حطس ٍد یَتحه رازکت E ٍ 200 تاتسا مزگ یليه DL لَفزكَت ( TA ) زّ ی ک حطس جٌپ اب 0 ، 100 ، 200،000 ٍ 000 ذيسا مزگَليك زّ رد مزگ یليه L ( کيبرَکسآ AA لکض ِب ُزيج رد ) L ليبرَکسآ 2 تافسفٌَه ( AMP ) .ذًذض ِلَهزف زيج ُ ¬ یاّ كزت ي ب ی ٍ ذقاف ٍُزگ ٍد رد ی هات ي ي E ٍ فلتخه حَطس اب ی هات ي ي C :لهاض E0C0 ، E0 C100 ، E0 C200 ، E0 C400 ٍ E0 C800 ٍاح ٍُزگ ٍ ی 200 ه ي ل ی ييهاتیٍ مزگ E مزگَليك زّ رد ج ي ُز ٍ فلتخه حَطس اب ی هات ي ي C :لهاض E200 C0 ، E200 C100 ، E200 C200 ، E200 C400 ، E200 C800 یحازط داذعت .ذًذض 200 ّاه ِچب دذع ی طسَته ىسٍ اب 66 / 1 ± 0 / 22 مزگ رَطب یٍاسه اّ ذحاٍ رد ی اهسآ ی ط ی سَت ی ع تذه ِب ٍ 12 ج اب ِتفّ ي ُز اّ ی ذغت قَف ی ِ اپ رد .ذًذض ی ىا ُذض بسك ىسٍ ،شرٍزپ ُرٍد ( WG ) ّاه ي ىا ذغت ی ِ ج اب ُذض ي ُز اّ ی E0 C400 ٍ E0 C800 ٌعه رَطب ی راد ی سً ّاه ِب تب ي ىا ذغت ی ِ ُذض E0C0 ٍ E0 C100 دَب زتلااب ( p< 0.05 ) اراك ،ذضر ذًٍر . یی اذغ اّ صخاض ٍ ی ًَخ ی ، ب ي ضَ ي و ي ا یی شًآ ٍ ی ن اّ ی ذبك ی ّاه ِچب ي ىا ذغت ی ِ ٍاح ُذض ی 200 ه ي ل ی ييهاتیٍ مزگ E سا کی زّ رد ييهاتیٍ حَطس C ٌعه فلاتخا ىٍذب ی ٍّزگ ىٍرد راد ی ( p>0.05 ٌعه رَطب ،) ی راد ی ٍ ذقاف ٍُزگ ِب تبسً ی هات ي ي E دَبْب ی ذٌتفا ا. ی ي وّا ُذٌّد ىاطً زها ي ت ب ي زتط ٍ ی هات ي ي E ج ي ُز ٍ ِب تبسً ی هات ي ي C ه ی ه ِچ زگا .ذضاب ي ىاش ٍ ی هات ي ي C ّ ي چ ثات ي ز لٍ ،تضاذً ُذض ِیذغت ىايّاه یگذًاهساب ذصرد زب یراد یٌعه ی ًِاطً ¬ یاّ دَبوك ىآ سا ليبق زيخات ذضر ٍ یب ا ییاْتض رد ىايّاه ِیذغت ُذض یتح د ر ٍ فلتخه حَطس ی هات ي ي E دزگ ُذّاطه ی ذ اتً ِب ِجَت اب . ی ج ييهاتیٍ دَبوك ترَص رد زضاح ِعلاطه

Effects of Photoperiod Manipulation on Growth Performance and Hematological Responses of Juvenile Caspian Roach Rutilus rutilus caspicus

A 8-week trial was conducted to evaluate the effects of photoperiod manipulation on the growth performance and hematological parameters of juvenile Caspian roach, Rutilus rutilus caspicus (average weight 1.46 ± 0.12 g mean±SD) reared under five photoperiods (24 h Light, 24L; 18 h Light & 6 h Dark, 18L:6D; 12 h Light & 12 h Dark, 12L:12D; 6 h Light & 18 h Dark, 6L:18D; 24 h Dark, 24D) with constant light intensity 1,500 lx on the water surface. Triplicate of 20 fish were allocated into each of 15 fiberglass tanks of 50 L capacity and they were fed three times per day with the commercial feed (SFK, Co., Sari Iran) contains 50.0% protein and 10.5% lipid. At the end of experimental period, final body weight, weight gain and specific growth rates of fish exposed to 24L were significantly higher than those of fish exposed to 12L:12D, 6L:18D and 24D (P < 0.05). Red blood cell and hemoglobin of fish exposed to 24L were significantly higher than those of fish exposed to 24D. No significant difference observed in hematocrit, white blood cell and plasma glucose among the different treatments groups. Therefore, these results demonstrated that the growth performance of juvenile Caspian roach can be significantly stimulated by using 24L and 18L:6D photoperiods without any measurable significant stress response such as plasma glucose concentration.