نشریه پژوهش های ماهی شناسی کاربردی
سال پنجم شماره 2 (تابستان 1396)

So far, the Caspian black-striped pipefish (S. caspius) is the only recorded species of the Syngnathidae in Caspian Sea. In this research, 50 specimens of pipefish were collected from brackish water of Gorgan Bay, and the basic information related to 21 morphometric and 6 meristic characteristics and population dynamic parameters including L-infinity, t-zero , instant growth rate, and condition factor were estimated. Results show the existence of two distinct populations with significant differences in some morphological parameters, especially in eye diameter, snout length, anal and pectoral fins height and mouth height in pipefish inhabiting southeast Caspian Sea. However, there was no significant difference between the two populations in meristic characteristics. Aging using opercula revealed 5 age groups (0+4). The maximum total length was observed 144 cm (3 years) and 149 cm (4 years) in male and female genus, respectively. Von Bertalanffy model was Lt=177.94 (1-e0.3(t.56)) and Lt=153.69 (1-e0.3(t.07)) for Caspian population and semi-Black Sea population, respectively. Growth pattern was reported as negative allometric model in two populations. Separation of the studied populations in Gorgan Bay were proved via investigating some biometric parameters of Caspian pipefish using multivariate statistical methods of PCA and DFA. Final identification of species or subspecies needs genetic studies.
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This study was conducted to investigate reproductive biology of white cheek shark (C. dussumieri) in Hormozgan waters, Persian Gulf. Sampling was done during six months from December 2013 to May 2014. 605 gonad samples including 289 female sharks and 316 male sharks caught by large head hairtail mid-water trawls and gillnets were analyzed. Results indicated that females were mature at body length range of 60-68 cm and their maturity size was 64.17 cm. Also, males had mature gonads at body length range of 61-68 cm and their maturity size was 63.14 cm. The number of observed embryos in uterus was 1-3 and their average length was 26.7±1.05 cm. The average number of embryos per birth was calculated as 2.31±0.067. Clasper length and total body length showed a sigmoid-shape function. Clasper length sharply increased from the size of 63 to76 cm and then decreased when the shark reached the upper-limit size (76 cm). All the sharks larger than 61 cm had a hard clasper and those smaller than 61 cm showed a smooth clasper. GSI analysis indicated no significant difference among various seasons for both males and females. According to the observations, no distinct seasonal breeding pattern was detected for this shark species. Results from the present study can be used as basis for the future comprehensive study.

To study Tigertooth croaker (O. ruber) diets, monthly sampling was done from March 2015 to February 2016, using commercial fisheries in the Khoozestan coasts. Totally, 307 fish were examined. The average of gastro-somatic index, condition factor, intensity of fullness and the vacuity index were calculated as 0.1±0.01, 0.99±0.04, 167.89±54.83 and 50.1, respectively. Also, frequency of occurrence index for fish and shrimp as the preys were calculated as 82.1% and 19.8%, respectively. The Relative importance index of fish and shrimp were calculated as 9.53 % and 8.62%, respectively. The intestinal contents of Tigertooth croaker (O. ruber) contained fish belonging to mugilidae and shrimp of Penaeidea family. The results of present study in Khuzestan coasts showed that this species has the optimum condition factor of fullness in spite of weak index of nutrition. It can be suggested that Tigertooth croaker (O. ruber) is a tolerant species, adapted to the environmental condition in that despite receiving low amount of food, it would gain the enough energy to manage its growth and physiologic process. It is concluded in this study that the main food of Tigertooth croaker (O. ruber) was fish and the secondary food was shrimp.

The main objective of this study was to evaluate some health indices in rainbow trout (O. mykiss) broodstock via enhancing their food quality by adding two sources of astaxanthin (synthetic and algae) in feed.. 7 groups consisting of 6 treatments of two different astaxanthin levels and sources and a control (without astaxanthin) were considered. So, algal astaxanthin (Haematococcus pluvialis) in the three levels of 2.67, 3.55 and 8 gr/kg food (T1,T2, T3) and synthetic source in three levels of 40, 80 and 120mg/kg food in diet (T4, T5, T6) were examined on trout broods (3-4 years) for 120 days before the spawning season. Significant difference was observed among the treatments in terms of health-related blood factors. The broods which were fed with algal astaxanthin had lower blood sugar. Changes in albumin revealed that with the increase in astaxanthin the albumin level was increased first and then decreased. While the change in serum globulin treatments containing synthetic astaxanthin was not regular, it was so in algal astaxanthin. Overall, the results asserted that the application of astaxanthin improves health indices of rainbow trout broodstock. It also concluded that algal astaxanthin (Haematococcus pluvialis) for the reason that it contains supplementary nutritious, is extraordinary preferable than synthetic astaxanthin to improve health indices of rainbow trout broodstock.

This study aimed to investigate some of serum electrolytes and white blood cells of wild stellate sturgeon (A. stellatus) which have been caught off the coast of Mazandaran by trawl methods during 5 maritime patrol from 2009 to 2010. Initially, 2 ml blood samples of 30 wild juvenile stellate sturgeon were extracted for spread of differential blood count, and serum electrolyte to test factors such as calcium, magnesium, cholesterol, albumin and total protein were separated. To conduct statistical evaluation and comparison, fishes were divided into two weight groups of 10 – 30 gr and 31 – 50 gr. Result of differential count showed that the most and the least abundance of leukocytes were belonged to lymphocyte and monocyte in both two groups, respectively. Serum electrolytes results showed that mean levels of cholesterol, calcium, magnesium, albumin and total protein in A. stellatus at group 1 were 28.1 ± 10.6 mg/dl; 24.7 ± 1.6 mg/dl; 26.7 ± 1.8 mEq/l; 1.4 ± 0.3 g/dl and 2.2 ± 0.3 g/dl, respectively. At group 2, these parameters levels were 71.14 ± 2.4 mg/dL, 20.6 ± 0.8 mg/dL, 17.4 ± 3.4 mEq/L, 1.6 ± 0.2 g/dl and 2.3 ± 0.2 g/dl, respectively. No significant difference was observed between the white cells counts of the two groups. There was a significant difference between cholesterol, calcium, and magnesium levels in each two groups, but results showed no significant difference in total protein and albumin between the two groups. Overall, based on the results of this study it can be concluded that in natural environments, due to the weight of fish, there is little difference between the measured blood indexes.

Today, nanotechnology is developing quickly and may have significant effects on industry, society and the environment. Therefore, in the present study, changes in muscle and liver enzymes of Common Carp (C. carpio) in the face of iron and zinc oxide nanoparticles were studied. For this purpose, first 420 common carp (with an average initial weight 45±3.2 g) was prepared. Then the fish were disinfected and adapted with laboratory conditions for a week and. Samples were randomly divided in to 7 groups. The first group was set as control and others received 10, 50 and 100 micrograms of iron and zinc nanoparticles per gram of food for 60 days. Histological studies showed that iron and zinc nanoparticles caused repair and growth of muscle tissues in treated groups fed with nanoparticles in comparisonwith the control group. More specifically, with progress in time and an increase in concentration, Iron nanoparticles in comparison with zinc oxide nanoparticles can cause more rapid deterioration in texture. In addition, the findings showed that serum levels of liver enzymes in fish fed with nanoparticles is changed compared to that in the control group in that the ALT and AST enzymes were significantly increased compared to the control group. It can be concluded from aforementioned results that iron and zinc nanoparticles are useful in recovery and muscle repair but also causes changes in liver enzyme levels which requires further investigation in this field.

The aim of this study was to assess the effects of triploidy and tetraploidy induction on survival, growth performance and response to transport stress in rainbow trout (O. mykiss) fry (with a weight range of 2-2.5g). To this purpose, 8 female (1600±246 g) and 6 male (1393±186 g) rainbow trout broodstock with the mean age of 4 years were used. Ten min. after insemination, the eggs were subjected to heat-shock for 10 min. submerged in a 28 °C water bath to induce triploidy. Tetraploidy was also induced by a thermal shock at 65 hour-degrees after fertilization in a 28 °C water bath for 10 min. Based on measuring area and volume of red blood cells, the overall triploidization and tetraploidization success level was 87.1±1% and 68.21±2%, respectively. Survival rate from fertilization to eyed stage in triploids (86.31 ± 1.21%) was significantly lower than that in diploids (92.12± 1.59%). Survival rate from eyed stage to hatching in triploids (94.04 ± 1.33%) was also significantly lesser than that in diploids (98.10 ± 0.45%). Survival rates of tetraploids in the three stages were significantly lower than those of the other experimental groups. After transportation stress, cortisol concentration in triploid fish (67.33 ± 4.48 ng/ml) was higher than that in other groups. The results showed that both triploidy and tetraploidy induction can lead to decreased survival rate. Moreover, the survival rate and physiological response of tetraploid fish to transportation stress is different from triploids but almost similar to diploids.

This study was conducted to assess the effect of dietary including aqueous extracts of red onion skin, red beetroot and red cabbage on ornamental parrot fish skin coloring for an eight-week experiment. The study was conducted on 144 fish of initial weight of approximately 2.7 ± 0.1 gr that were established in a CRD experimental design using three treatments with the natural extracts added to fish dietary and a control group with no extract added to dietary , and conducted. The skin colorations of the groups were measured with Color Meter set TES 135 (L*a*b and XYZ parameters) and the carotenoid concentration measurement method. The Results showed that the most effective enhancement of skins pigmentation (parameter *a) of fish was due to red beetroot extract. In addition, the most carotenoid pigments accumulation on the fish skin, operculum and fins was observed with dietary including beetroot extract, and done so on the fish flesh with dietary including red onion extract diets. Concerning the fish feature coloration, the beetroot, onion skin and red cabbage extracts in diets presented the significant variations of colorimetric values (L*a*b) and carotenoids concentration throughout the feeding in comparison with the control.

This study was conducted to compare some digestive enzymes activity in juvenile Sobeity Seabream (S. hasta) under the effects of different dietary protein and lipid levels. 6 dietaries including 3 levels of protein(35, 40 and 45%) and 2 levels of lipid (7 and 14%) were determine in treatments 1 to 6. The fish with mean initial weight of 36.55±0.28 g were randomly stocked in triplicates (10 fish/tank) in eighteen 300 l tanks filled with filtered sea water at 27 ppt. The experimental fish were fed to apparent satiation thrice daily for 56 days. After the treatment period, digestive enzyme activity including total protease, alkaline phosphatase and alphaamylase was calculated. Results reveled that activity of alkaline phosphatase and totalprotease were significantly affected bydietary protein levels whereas alphaamylase activity was not affected significantly by dietary protein. No significant differences in the activity of the alkaline phosphatase and alphaamylase activity were observed at different lipid levels whereas total protease showed a significant increase at 14% lipid. A direct relationship was observed between the increase in alkaline phosphatase activity and the little decreasing trend in alphaamylase enzyme activity on the one hand and the increase in dietary lipid levels on the other hand. The interactionof dietary protein and dietary lipid significantly affected total protease activity. Results showed that efficient use of protein, digestive enzyme activity development, growth improvement and food production cost effectiveness are possible through making a balance between 40% of protein and 14% of lipid in dietary of S. hasta. In addition, determining the ratio of alphaamylaseenzyme activity to proteasecan show fish adaptability to nutrition conditions.

This study was conducted on 270 individuals of rainbow trout kept in the research farm of Aquatic Animal Health research Center, Veterinary Hospital in Karaj, Mardabad from January 2012 until the end of March 2013. The fish have been chosen from three sources, provinces of Chahar Mahal Bakhtiari, Markazi and Mazandaran. In this study, the highest and lowest infection prevalence was related to Ichthyophthiriusmultifiliis and Chilodonella sp., respectively.Chi-square analysis was used for statistical analysis. A total of 166 samples out of 270 samples (61.5%) showed the infection by ectoparasites including: Ichthyophthiriusmultifiliis with 99 pieces (36.7%), Trichodina sp. with 18 pieces (6.7%), Chilodonella sp. with 7 piece (2.6%), Gyrodactylus sp. with 20 pieces (7.4%) and Lernaea sp. with 22 piece (8.1%).