نشریه پژوهش های ماهی شناسی کاربردی
سال هشتم شماره 1 (بهار 1399)

Population parameters of Common silver-biddy (Gerres oyena) were studied in Hara Biospher Reserve from September 2016 to August 2017. All fishes were sampled by boat trawl, beach seine and trapping barriers. Growth parameters were determined using the monthly length–frequency data. The Mean total length was calculated 8.5±1/35 cm for Common silver-biddy. The value of L∞ and K were calculated 18 cm and 1.5 yr-1 respectively. The rate of natural mortality (M) were estimated 2.68 yr-1. The length-weight relationship were determined as W= 0.0088 L 3.21 and W= 0.00887L 3.21 for Common silver-biddy. Results showed these fishes were juvenile and emphasized on supporting roles of creeks for Gerridae as nursery ground.

In this study, hepatosomatic, gonadosomatic and condition of Alosa species were studied. A sampling were done from 5 stations (Rossdar, Clachay , Chaboksar, Chamkhala and Kiyoshahr) was arried out on the eastern coast of Gilan in 2016. A total of 693 sampling fish were collected. Samples were transferred to the laboratory in 10% formalin formaldehyde. Three species of Alosa namely Alosa.braschnikowi, A.caspia and A.Kessleri were identified, which were 354 samples (51.08%), 78 samples (25.3% 11%) and 261 individuals respectivetly (37.67%) were calculated.Fish were divide into 7 age classes (1 up to 7 years old), the highest percentage of A.braschnikowi population at age 3 (39.83%), A.caspia at age 4 (37.18%), and A.Kessleri species at age 4 (23 .40%). The highest mean (± standard error) in weight and length was observed in the A.braschnikowi species, which was 32.75 ± 05.027 grams and 38.39 ± 27.27 mm respectively. The lowest mean (± standard error) in weight and length was observed in A.caspia, which was 83.52 ± 53.13 and 11.32 ± 66.27 mm, respectively.In the three studied species of A.braschnikowi, A.caspia and A.Kessleri, the status index, gonadosomatic and hepatosomatic index (0.18 0.01, 0.12 ± 0.01 and 0.12, 0.01), (9.0 ± 0.04) 0.0 ± 0.06 and 0.77 ± 0/0) and (1.12 ± 0.0, 1.08 ± 0.04 and 1.2 ± 0.0), has no significant differences (p> 0.05). The sex ratio of the A.braschnikowi and A.Kessleri was 1: 1 (male: female), but in the A.caspia it was 1.33: 1.

This study conducted to study some biological traits of Carassius gibelio in Golestan dam and Voshmgir dam  from February to September 2015. During the study, 247 specimens from Golestan dam and 208 specimens from Voshmgir dam were sampled using small beach seine. The sex ratio of fish caught from Golestan dam to 1:10/23 and  the sex ratio of fish caught from the dam Voshmgir1: 10/56. The highest average gonadosomatic index (GSI) in Golestan dam for female to male June and May, respectively, were observed for females and males respectively 12/20 and 3/28 in the dam area Voshmgir for both female and male was observed on June 11/15 and 2/93 respectively for females and males respectively. The maximum total length and weight of Golestan dam area for females and males respectively 196/00 mm, 141/35 gr and 156/00 mm, 52/42 gr and in the dam area Voshmgir for females respectively 240/00 mm, 280/60 gr and for males was 00/179 mm, 81/75 gr. Minimum, maximum and mean absolute fecundity in Golestan dam with 327/71 respectively, 83134/09 and 13272/67 and in the dam area Voshmgir 4857/82, 430416/00 and 65270/02 and minimum, maximum and average were Relative fecundity (eggs per kg body weight) respectively in Golestan dam with 147/93, 5432/02 and 1002/48 and in the dam area Voshmgir respectively, with 100/94,  10722/34 and 1283/99 respectively. The mean diameter of 0/64 mm eggs in Golestan dam and from 0/11 to 1/39 and 0/62 mm and 0/13 to 1/11 Voshmgir dam area was variable.

The aim of present study was to compare levels of genetic polymorphism between offspring of  wild , farmed and mix of them of Roach (Rurilus rutilus caspicus) using five microsatellite loci  (CA1, CA7, CypG27, Lid1, Rru4). Genetic diversity was investigated by studying samples collected from three population, 90 fish, thirty specimen form each population. All samples fixed in ethanol 96% until DNA extraction. The average number of alleles in wild, farmed and mixed brood stock offspring were 10.4 and 10.4 and 9 alleles, respectively. A twenty nine total alleles were observed in all three populations. The numbers of effective alleles of wild, farmed and mixed offspring were 6.78, 7.58 and 6.80 alleles in each population, respectively. The Allele frequency among wild, farmed and mixed population were 7, 8 and 8, respectively.  All frequency decline in wild fish due to inbreeding and genetic drift. The mean of observed heterozygosis (Ho) values were 0.85, 0.77 and 0.85 in wild, farmed and mixed offspring respectively. Also effective heterozygosis (He) were 0.828, 0.859 and 0.849 in wild, farmed and mixed offspring respectively. Approximately, all of loci showed deviation from Hardy-Weinberg equilibrium. The genetic distance among of wild, farmed and mixed offspring populations were 0.459, 0.298 and 0.684, respectively. The results of Molecular Variance Analysis revealed that genetic diversity within individual was 90 percent, while among them was 3 percent. The Fst value was 0.032 that indicates the low genetic differentiation between the three populations which could be explained by the low number of alleles in three populations. Furthermore, the Natural Migration (Nm) between two stations was obtained 7.394. UPGMA cluster analysis based on genetic distance showed that the breeding population and combined in a separate branch of the branches are wild population.

There were numerous reports that lymphatic structure organs differences in histomorphological structurs during cold and warm seasons. 10 healthy Persian sturgeon with same size respectively was taken from pools in both winter and summer, with water temperature of 7/30 and 27/90 ° C from Beheshti sturgeon cultivation and breeding centre of the international sturgeon research institute of doctor Dadman of Rasht. After biometric, 0.5 centimeter samples of anterior, middle and posterior of intestine were removed and placed in formalin fixative solution. Then, the samples were prepared using standard methods and conventional tissue sections, 4-6 microns thick slices were prepared and stained by H&E. Results showed the number of lymphocyte in intestinal epithelial tissue in both cold and warm season, showed a significant difference and their density of it was more in the cold season compared to warm season (p<0.05).This shows the immune system influence of temperature changes especially in cold seasons.

In recent years, anthropogenic and natural activities have caused high levels of metal contamination into the aquatic ecosystem. These pollutants can accumulate in the food chain. The present study examined the amount of metals such as lead ,Nickel, Zink, Copper and Iron in the muscle tissue of Silago Sihama because of their importance in three regions of the Hormozgan province.Sampling was done in three station (Qeshm, Khamir Port and Pol Port) and two seasons, winter and summer. After bioassay, the samples of Silago Sihama were prepared through Chemical digestion method and the amount of metals was measured using atomic absorption device. The results obtained for the concentration of metals (Pb, Ni, Zn, Cu and Fe) in muscle of short fish showed that, there were significant differences between stations (Qeshm, Khamir Port and Pol Port), and also between winter and summer seasons (p<0.05). In both cases in the winter and summer, lead ,Nickel, Zink, Copper and Iron concentrations in Qeshm were significantly higher than Khamir Port and pol Port. Comparison of the metal concentrations in fish muscle tissue shorts with standard values showed that the concentrations of lead, Nickel, Zink, Copper and Iron were lower than FAO, WHO and EPA standards. Food risk assessment of case study specie indicates that the consumption of Silago Sihama with the current consumption rate causes no danger to consumers from the viewpoint of lead, Nickel, Zink, Copper and Iron.

In this study, the effects of replacing fish meal with soybean meal on growth performance, feed efficiency, body composition, fatty acid profile and gut lactic acid bacteria of beluga sturgeon, Huso huso. Nine diets were formulated (40% crude protein) in which soybean meal was replaced by fish meal at 0 (control), 40 and 80% supplemented and with three multi-enzyme level 0, 1 or 2 g/kg of Kemin multi-enzyme. Fish were fed on experimental diets for 12 weeks at 1% body weight. Addition of soybean meal decreased growth performance and the effect was more pronounced when with increasing levels of soybean meal (P<0.05) and minimum final weight occurred at 80% of fish meal replaced by soybean meal. Body fatty acid composition was affected by dietary treatments. Fish fed the control diet; diets with enzyme supplementation (without the addition of soybean meal) as well as diets 4 and 5 (40% soybean meal; 0 or 1 g/kg enzyme) had the highest n-3 and eicosapentaenoic acid. In contrast, soybean meal at an inclusion level over 40% negatively influenced n-3 fatty acid. The lowest content of eicosapentaenoic acid and docosahexaenoic acid and n-3 fatty acid was observed in fish fed diets with 80% soybean meal without the inclusion of enzyme (treatment 7). Addition of soybean meal at both 40 and 80% replacement level regardless of enzyme supplementation increased the number of gut Lactococcus lactis, Lactobacillus carvatus, Pediococcus pentaseceous, Lactobacillus plantarum, total aerobic counts and total anaerobic counts. The highest number of bacterial counts occurred in diet containing 80% soybean meal with 2 g/kg enzyme (treatment 9) (P<0.05). The results of this study indicated that soybean meal with enzyme supplementation at 2 g/kg can substitute 40% for fish meal in commercial diets of great sturgeon.

Starvation periods of fish in during the developmental stages on growth indices and blood factors can be affected. The effects of compensatory growth on growth indices and physiological responses (glucose, total protein and cholesterol), study for 8 week investigated in Juveniles of common carp (Cyprinus carpio). The fish were divided in 4 experimental groups with initial weight (13/88±0/88 gr) in triplicate that included: 0 (T1) 2 days (T2), 4 days (T3) and a week (T4) starvation and refeeding periods each with 3 replicates were suffered. At the end of testing blood samples for biochemical analysis of each of the treatments used and metabolites were measured by spectrophotometry methode. Results showed growth indices including the final weight, growth rate, specific growth rate and body weight gain in the control and treatment 2 days a week of starvation were significantly different (p<0.05) but between treatments 1 day starvation and control there was no significant difference (p>0.05). The condition factor and feed conversion ratio in all treatments no significant difference (p>0.05). glucose levels between treatment starvation and control groups showed significant differences (p<0.05) but the total protein and cholesterol were not significantly different between control and starved treatments (p>0.05). The results suggest that commomcarp has the physiologic adjustment ability to short-term starvation and re-feeding period.

this experiment was carried out to investigate the effects of supplementing two macroalgae Sargassum cristaefolium and Gracilaria pygmaea extracts in feed on some growth indices, hematology and blood constituents of juvenile rainbow trout (Onchorhynchus mykiss). Rainbow trout were randomly divided into four groups: a control group was fed with basal diet, and three treated groups fed with basal diet supplemented with 500 (mg/kg) S.cristaefolium (SA), 500 (mg/kg) G.pygmaea (GL) and 250 (mg/kg) S.cristaefolium + 250 (mg/kg) G.pygmaea (SA+GL) for 8 weeks. The fish were fed 4 times by hand to apparent visual satiation and water was changed every day. Results showed that growth factor such as final fish weight, specific growth rate (SGR), weight gain (WG) and condition factor (CF) were not significantly different among treated groups (P > 0.05). Hepatosomatic index (HSI) was significantly higher in fish fed control or SA diets (P < 0.05). Among the blood parameters, hemoglobin levels in fish fed diet containing gracilaria was significantly higher than the control group (P < 0.05). Among the biochemical composition of blood, group fed the control diet had higher triglycerides level compared to the groups fed diets containing sargassum or a mix of sargassum and gracilaria (P < 0.05). These results indicated that dietary supplementation of sargassum and gracilaria extracts in rainbow trout feed had not significant impacts on growth performance and blood parameters of this fish.

This study was conducted to compare the morphometric and meristic characters and biological parameters including length-weight relationship parameters and condition factor comparison of Urmia bleak (Alburnus atropatenae</em>) from Mahabad-Chaie, Ghale-Chaie and Gedar-Chaie rivers of Lake Urmia basin.  A total of 20 morphometric and 7 meristic traits were measured. Morphometric data was standardized to eliminate the effects of allometric growth. One-way ANOVA analysis were used for comparison of traits. The results of morphometric data showed a significant differences in all traits except fork length, ventral- pectoral and ventral- anal distance, pre and post dorsal length, head length and eye diameter. PCA, CVA and Cluster analysis were performed with these traits. CVA showed that Gedar-Chaie population distinguished from other populations, confirming by Cluster analysis. Also, studied population in terms of meristic traits showed a significance differences in branched rays of dorsal and anal fins lower gill rakers. Also, length-weight (LWRs) parameters and condition factor were estimated. Based on the results, the b</em> values was 3.26 and 2.75 also condition factor were calculated 1.02 and 1.18 for the Mahabad-Chaie and Ghale-Chaie populations, respectively. Higher condition factor reflects the relatively favorable condition of their habitat in the studied rivers.