Iraqi Journal of Aquaculture

This study aims to explain the effect of salt stress on Grass carp Ctenopharyngodon idella. It includes two parts, the first to determine the LC50 during abrupt increase in salinity to 5,10 and 15g/L.While the other part concerned with the physiological effects of the gradual increase in salinity to 5 and 10 g/L on osmoregulation, by measuring ions concentration ( Na+, K+ ) in the blood plasma and muscles ,water contents in the muscles , numbers and percentage of chloride cells in the gills epithelia, beside studying the expenditure of osmoregulation by measuring the rate of oxygen consumption, the levels of glucose and total protein in blood plasma. The results showed that the Grass carp has a narrow salt tolerance with LC50 7.5g/L. Osmoregulation study showed an increase in the concentrations of ions( Na+ and K+) in the blood plasma and muscles with increasing salinity to 5 and 10 g/L and the water levels in the muscle increase with increasing salinity. These changes are parallel with the increasing percentage and numbers of chloride cells in the gills. The oxygen consumption rate was increased with increasing salinity to 5 and 10 g/L .There was a decrease in the total protein and increase in the glucose levels with increasing salinity to 5 and 10g/L which reflect an increase energy consumption for osmoregulation. It was concluded, that the Grass carp does not have resistance to high salt concentration over 10 g/L, and the acclimation occurred in salt concentrations between 5 and 10 g/L with a new state of homeostasis and high consumption of energy for osmoregulation.

This study was carried out during the seasons of 2008_2009 to study effect of irrigation with fish culture effluent on quality and Lycopersicum esculentum (under green house) yield of tomato. The experiment consisted of four treatments: Irrigation with freshwater. (control), irrigation with fish culture effluent, irrigation alternately with fish culture effluent twice and freshwater once, irrigation alternately with fish culture effluent once and freshwater once. The experiment was done according to the completely randomized block design with four replicates. Soil and water samples were collected and analyzed. Results of the study showed: The irrigation in waste water fish ponds adds positive effect on quality and yield of Tomato under green house. This effect of water was on the irrigation with fishculture effluent increase the yield 17.82 Kg/m2 firstly followed by the treatment of irrigation alternately with fish culture effluent twice and freshwater once by yielding 15.47 Kg/m2. After that it was on irrigation alternately with fish culture effluent once and freshwater once by yielding 12.42 Kg/m2 comparing with-irrigation of freshwater. Which give lower yield 8.88 Kg/m2.

The isolation and identification of an alkaloidic compound similar to Calothrixin-A for were done here first time from the green algae (Chlorophyta) Cladophora crispata, isolated from Garmat-Ali river in Basrah in Iraq, purified and cultivated in Chu-10 medium. The growth rate was K=1.3 and the generation time G=0.23. The identification of the compound was made depending on its chemical and physical properties by using thin layer chromatoghraphy (TLC) and column chromatoghraphy. A single compound was isolated and tested by University and IR spectra. The melting point and solubility of the purified compound were determined using organic and inorganic solvents. The minimal inhibitory concentration (MIC) value was 5.5 μg /cm3 against G-positive bacteria Staphylococcus aurrus (ATCC25922) and 6 μg/cm3 against G-negetive bacteria Escherichia coli (ATCC25923). The toxicity of the alkaloidic compound was examined against human red blood cells and no toxic effect was detected.

Morphometric of examination of gonads of Liza carinata were performed for one year (October 1995 – September 1996) to study the maturation development. Monthly variation in gonado – somatic index (GSI) were noticed, that started with low values during October and November. Significant increase in (GSI) was recorded during the period December - April with the peak in February (3.59 in males & 9.33 in females) followed by a significant decline during May – September. Variations in hepato – somatic index (HSI) were related to feeding activity rather than gonadal maturation. Peaks of HIS & GSI were recorded at similar time period. On the contrary, the somatic condition factor (SCF) was closely related to gonadal maturation stages. Lower values (SCF) were recorded during winter months which showed higher values in GSI.