Salinity adaptation and sea water tolerance are vital, challenging phenomena in the life history of anadromous species such as kuttum fish. Evaluation on feed deprivation in gill chloride cell development of kuttum fish is the aim of this study. Kuttum juveniles that weighed an average weight of 0.5 grams were divided into two groups. One group (control) was fed ad libitum during the experiment. Fish in the other group were feed deprived. Both groups were exposed to the salinity challenge for 7 days. Gill sampling was performed on the second, third, fourth, and seventh days after salinity challenge initiation. Consequently, we evaluated Na+ K+ ATPase activity, gill chloride cell numbers and size. Results showed a significant decrease in gill Na+ K+ ATPase activity, chloride cell diameter, perimeter and area due tofasting. Based on the obtained results we concluded that feed deprivation might have a disruptive effect on chloride cell development during seawater adaptation.

The present study investigated the effects of different dietary nettle (Urtica dioica) levels on biochemical, hematological and immunological parameters in beluga (Huso huso). Fish were divided into 4 groups before being fed for 8 weeks with 0%, 3%, 6% and 12% of nettle. The blood samples were collected on week 4 and 8. The use of nettle did not significantly change the mean cell volume, mean cell haemoglobin, lymphocytes, eosinophils, albumin, glucose, alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase and lysozyme activity on week 4 and 8. After 4 weeks, the total red blood cell (RBC) and hematocrit (Ht) showed a significant increase in 12% nettle group compared to the 3% nettle and control groups but haemoglobin (Hb) had a significant change in 12% nettle compared to the control. At the same time was not found a significant change in the mean cell haemoglobin concentration (MCHC), total white blood cell (WBC), neutrophils, respiratory burst activity (RB), total immunoglobulin (Ig) and total protein (TP), triglyceride (Tri) and cholesterol (Chol). After 8 weeks, the fish treated with nettle exhibited significantly increase in neutrophil and Hb levels compared to the control and between treatment groups, 12% nettle group shown the highest Hb while RBC and Hct values significantly rose in fish fed by 12% compared to the control. Supplementing 6% and 12% nettle increased the WBC and MCHC compared to the other groups. The group fed 12% showed a highly significant difference in RB, TP and Ig after 8 weeks. However, Tri and Chol were significantly decreased in the juvenile beluga fed by the 6% and 12% nettle diet compared to the other groups. The results suggest that by using this herb there will be an improvement in hemato-biochemical parameters and immune function of juvenile beluga.

The sensitivity of the neotropical freshwater fish Cyprinus carpio to copper was evaluated at low and high water pH. Juvenile fish were acclimated at 27±2°C and exposed to copper sulphate in water with pH 5.0 and 9.0. No copper was added to controls groups in water pH 5.0, 9.0 and 7.5. The obtained results in copper-exposed group with alkaline water showed a decrease in RBC, Hct and Hb than those kept in copper-exposed group in acidic water. WBC showed an increase in copper- exposed group in acidic water than those kept in control pH 7.5. Lymphocite in copper-exposed fish in water pH 9.0 and 5.0 showed a decrease in relation to those kept in control pH 7.5. Glucose in control pH 9.0 group, decrease compared to control pH 7.5. Total Protein in control pH 9.0 and in copper-exposed fish in acidic water and alkaline water decreased compared to control pH 7.5. It was concluded that Cyprinus carpio is affected by the change of water pH and heavy metal in alkaline water which in turn affect the hematological and some biochemical parameters of fish.

The salinity tolerance, hematological and hydromineral regulation capabilities of juvenile Russian sturgeon (Acipenser gueldenstaedtii) were investigated in different ages and sizes in freshwater (FW: <0.5 parts per thousand), estuary water (EW: 9.5 parts per thousand) and Caspian Sea water (C(S)W: 12.5 parts per thousand). The fish were directly transferred from FW to EW and C(S)W. The possible repercussions of ion-osmoregulatory processes on some classical indicators were examined at the end of 168 hours fish salinity tolerance. The mortality was not more than 35% in EW and C(S)W in both groups. The survival percent and salinity tolerance were increased with increment of age and size of fish. The functional mechanism of osmotic and ionic homeostasis were similar in all groups (p>0.05) but differed in experimental media (p<0.05). Significant differences were observed between the levels of plasma ion concentrations in different media (p<0.01). Plasma Na(+), K(+) and Ca(+2) concentrations were higher than those of FW media, but lower than in C(S)W media (p<0.05). Plasma Mg(+2) concentrations were lower than those of FW and C(S)W media, but near to EW media (p<0.05). The hematocrit mean cell volume decreased but mean cell hemoglobin concentration, osmolarity and levels of plasma cortisol were increased from FW media to C(S)W media (p<0.05). The hemoglobin concentration (Hb), the amount of hemoglobin per erythrocyte, red and white blood cells count did not change (p>0.05). However, the results showed that the above parameters in fish fingerlings did not return to initial values in the new environment and then physiological changes happened.

ies composition, cell abundance and biomass of phytoplankton in the southern part of the Caspian Sea were investigated. This survey were fulfilled in 6 transects and 26 stations. A total of 260 samples were collected during winter to autumn in 2005. Totally, 163 species of phytoplankton were identified, including phyla Bacillariophyta (71 species), Chlorophyta (31 species), Cyanophyta (27 species), Pyrrophyta (21 species), and Euglenophyta (13 species). The overall total average of cell abundance and biomass of phytoplankton were 56.30± 30.97 ×10 6 cells/m 3 and 221.70±75.87 mg/m 3 , respectively. Bacillariophyta accounted for 47% in cell abundance and Pyrrophyta consisted of 53% of the phytoplankton biomass. Maximum phytoplankton population was recorded in winter due to Bacillariophyta and the maximum biomass was recorded in spring due to Pyrrophyta. The maximum density of Bacillariophyta was in winter and autumn while maximum biomass was observed in spring due to larger size of Bacillariophyta such as Rhizosolenia calcar avis and Nitzschia sigmoidea followed by Pyrrophyta (Exuviaella cordata) with high cell abundance throughout the year.

2 Abstract: Three ranges of salinity (fresh water (FW: 0.05). The Hct, MCV, MCHC, cortisol, osmolarity and ion concentration values did not return to initial values (p<0.05), showed that osmoregulatory processes caused major physiological changes in this species.