Regarding to measure some hematological factors of Caspian Salmon (Salmo trutta caspius), 55 immature and 21 mature individuals were studied. The main results were:                                                                                immature                                mature- Hemoglobin value (gr/dl)                                  7.20                                        9.87- Hematocrit (%)                                                   34.1                                        39.2- Mean No. of red blood cells (per mm3)          934300                                   1306200- Mean No. of white blood cells (per mm3)       8380                                       6219- Mean No. of platelets (per mm3)                     21180                                      13159As the results showed the number of white blood cells and platelets in immature individuals were more than mature specimen.The obtained results of blood indices were as follow:                                                                                immature                                matur- Mean MCV (FL)                                                385.4                                       302.9- Mean MCH (Pg)                                                82.0                                         75.5- Mean MCHC (%)                                               21.6                                         25.6- Lymphoc)'te (%)                                                96.1                                         69.9- Neutrophil (%)                                                   3.4                                           29.4- Monocyte (%)                                                    0.52                                         1.14Notice: Eusinophil and basophil cells weren't observed.

Salmo trutta caspius is a commercial migratory fish species in the Caspian Sea. Over fishing and deterioration of natural spawning grounds of the species are two major causes depressing stocks of the fish in the Sea. Thus, artificial breeding and release of Salmon juveniles into the Caspian Sea is now considered an urgent need towards the rehabilitation of the stocks of the fish.This study was conducted in early 2004 to determine the ideal weight for the release of Salmon fry in order to increase fishery return coefficients in the species. For this research, we used facilities of the Marine Fisheries Breeding and Research Center in Ghazian, along the coastal areas of the Bandar Anzali. Salmon juveniles used in this study belonged to the same generation. Fishes belonging to different weight classes (5, 10, 15 and 20g) were selected in a random design and stocked in two groups of sea water at 7% salinity and freshwater. Osmosis was studied using blood samples collected at 0, 3, 6, 12, 24, 72, 168 and 240 hours. Heparin tubes were used for sampling blood which was centrifuged to separate blood plasma. Osmotic pressure was determined using osmometer.Statistical analysis of the results on variations in osmotic pressure showed that after 10 days of stocking fish in seawater (7%), fishes in all weight classes were capable of osmoregulation. Also fishes in weight classes 10, 15 and 20g were capable of osmoregulation in the Caspian Sea water.

One of the most important and influential stress causing problem and secondary diseases in fish is transport stress. The aim of this study was to evaluate the physiological effects of acute stress of fish transportation on some biochemicals in Salmo trutta caspius. A total of 100 fish were transported in plastic bags for 6 h and then released in 300-l tanks. Blood samples were taken after 6, 12, 24 and 48 h after a 6-h transportation (n=15). Based on the results, blood glucose increased compared to the basal value (p<0. 05) after 6 h but the value was decreased at 12 and 24 h compared to that of 6 h. Cortisol value was increased significantly (p<0. 05) in all sampling times. Unexpectedly, protein content was significantly increased (p<0. 05) at 24h. On the other hands, other parameters uch as Na+, Cl-, K+, did not show a significant variation after transportation (p>0. 05).

The optimum dose of ultraviolet (UV) irradiation to produce gynogenetic Caspian Salmon, Salmo trutta caspius, with emphasis on the "Hertwig effect" and photoreactivation (PR) were investigated. The sperm of Caspian Salmon was irradiated with UV at 2010 ± 200 mw.cm-2 in different times including 0, 1, 3, 5, 8, 10, 15, 20, 25, 35 and 45 min and was allowed to fertilize normal ova; the fertilization, eyed and hatching rates were calculated to assess the performance. Using the irradiated sperm decreased the fertilization, eyed as well as hatching rates and the so-called "Hertwig effect" was observed, with the time-dependent decrease in the hatching rates at 0+ to 3 min irradiation, but better hatching rates were observed at more prolonged irradiation times. The best hatching rate was achieved at 25 min of UV irradiation; after that the survival rates rapidly declined to near zero. For PR studies, the semen was irradiated with UV (5, 30 and 120s) and untreated semen (0s) was used as control. Irradiated semen and/or fertilized eggs by treated semen were exposed to visible light (60 W) at a distance of 30 cm for 10 min; the eyed and hatching rates were measured. UV irradiation as low dose as 5s, significantly decreased the hatching rate (P <0.05). Semen and/or eggs illumination with visible light could not improve the survival rates (P >0.05). So, based on the results of this study, it was impossible to detect any PR mechanism in Caspian Salmon.

Caspian trout is valuable, Commercial, anadromous and endemic fish species in the Caspian Sea so that, researchers attention have been focused on this species. At the moment, only pay attention to stocks rehabilitation that fisheries organization releases more than 300,000 fingerlings to the rivers ends to the Caspian Sea. Importance of this study consist (1) introducing a new species to the aquaculture system and (2) provide breeders in this research. we used from 2 treatments that consist with density of 10 kg/m3 and 20 kg/m3 with 3 replication. Results showed, Mean weight gain in treatments with 10 and 20 kg/m3 reached to 1953.9 and 1734% that there were significant differences (ρ<0.05) in comparison with initial weight (10.1 gr). Special growth rate in 1 and 2 treatments were calculated 1.37 and 1.32% in day respectively that there were significant differences. Initial and end condition factor (CF) were 1.07 and 1.12 respectively. Fishes survival rate in 1 and 2 treatments determined 92 and 88 % respectively. Results showed, culture of Caspian trout is suitable with density 10 kg/m3, so that weight gain, SGR and Daily growth mean are better than treatment 2 (15-20 kg/m3).

Hematological and biochemical serum analyses were carried out in 131 fish specimens in three age and size groups including smolt, juvenile and breeder. Of these groups, smolt fish were 40 specimens in the average total length range 195.45±12.426mm and had an average weight of 84±15.5g, juvenile fish were 25 individuals and their average total length and weight were 267±20.877mm and 217.20±22.013g, respectively. The 41 breeder fish had an average total length of 578.24±68.487mm and an average weight of 1994.2±775.379g. Another 25 breeder fish were also sampled in the spawning season for blood biochemical analyses had an average total length range of 617±59.9 mm and weighed on average 2227.5±647.5 g each. Red blood cell counts were 866600 per mm3 and 1259400 per mm3 in smolt and breeder fish respectively. The average hematocrit was 48.39% in smolt and 44.29% in breeder fish. The average hemoglobin was 8.85g1d1in smolt and 10.91g/dl in breeder fish. White blood cell count was 8781.58 per mm3 in smolt and 5217.65 per mm3 in breeder fish. Other measurements were as follows: Lymphocyte 90.57% in smolt and 73.22% in breeders, Neutrophil 5.12% in smo1t and 16.92% in breeders, Monocyte 1.27% in smo1t and 4.24% in breeders, and clotting time was 282.34 seconds in smolt and 291.47 seconds in breeder fish. We also measured MCV, MCH and MCHC in smolt and breeder fish along with biochemical parameters. The glucose level was 2.97mmol/l in juvenile and 1.99mmoVl in breeder fish. The cholesterol level was 4.26mmol/I in juvenile and 7.06mmol.l in breeders. The triglyceride amount was 2.35mmol/l in juvenile and 2.47mmol/1 in breeder specimens and the calcium level was 2.44 in juvenile and 2.61 mmol/l in breeder fish.

The effect of specific nutrients on Salmo trutta caspius intestinal variation are practically unknown. The purpose of this work was to study the effects of different levels (0, 0.25 and 0.5%) of dietary nucleotide that added in control meal, on several segment of intestinal structure of Caspian Salmon juvenile with average 12.26±0.001 g weight (average length 11.1±0.002). This trial was achieved in fiber glass 300 liter fresh water tank with 35 fish in each one. Fish cultured in 8 weeks and experiment has done on fish with average 26 g weight.6 fish from each treatment captured, sacrificed and immediately gastro intestinal tract fixed by immersion into Bouin solution for histology. Then histological sections of 4 mm obtained, stained with Hematoxiline-Fushin and investigated. Results indicate that in duodenum nucleotide has a significantly (P<0.05) effects on villi length, thickness of muscle and sub mucosa. This treatment have been showed maximum of villi length and tickness of muscle. Similar results have been showed in ileum and jejunum. In this segments nucleotide have a significantly (P<0.05) effects on maturation and growth of villi length, muscle and submucosa.

We investigated the survival ratio and the growth rate of offspring of Salmo trutta caspius produced from three groups of brood fish in Shahid Bahonar Rearing and Breeding Center in Klardashtin 2005. The three groups of brood fish belonged the early, mid, and late-migration period. The sampling was done randomly, and in each group 15 female and 5 male fish were included. After spawning and hatching, 22500 eggs were used in each group (3 treatments, repeated 9 times). The results showed no significant difference in the survival ratio of the egg and larva in the three groups of the brood fish in each stage of evolution up to two months after the start of active feeding (P>0.05). However, after the start of active feeding there was a significant difference (P<0.05) in the growth ratio of offspring produced in the groups aged one and two months. The growth ratio of the same age offspring in the first group was higher than those in the third group (P<0.05); but there was no significant difference between the first and the second group, or between the second and the third group (P> 0.05). Based on the results, we suggest that the brood fish from the early migration period are more suitable for producing offspring and their offspring pass through the smoltification stage more rapidly. However, in terms of genetic diversity, it would be appropriate to use brood fish from all migration periods.

The influence of starvation and refeeding on the structure of liver was studied in the juveniles of Salmotrutta caspius. 480 juveniles were stocked into 12 outdoor concrete tanks (40 fish per tank), with four levels of feeding: full-fed for 6 weeks, 3 weeks starved, full-starved for 6 weeks and 3 weeks starved and 3 weeks fed. The liver was then removed from five individuals taken from each tank (5fish/tank, 3tank/treatment) fixed for 24 h in Bouins fixative. The samples were dehydrated through a graded series of ethanol solution up to 100% and xylene, embeded in paraffin, sectioned using microtome at 41lm thickness, stained using haematoxylin and eozin and examined using a Nikon light microscope. The results showed that the starvation influenced significantly the liver structure of the both starved groups as hepatocytes atrophy and reduction of their size (P<0.05). Cytoplasm was deteriorated and sinus enlargement was observed in the liver of starved fish. In addition, 3-week refeeding could be effective on liver regeneration leading to hepatocytes hypertrophy and increase of their size to the same size of the control group. In conclusion, food deprivation and consumption of energy resources caused tissue damage in the liver structure of Salmo trutta, but refeeding and fulfillment of energy resources may recover tissue damage.