Iraqi Journal of Aquaculture

This study was conducted to determine the effect of direct transportation of the common carp (Cyprinus carpio) fingerlings to salt solution of 4, 6, 8 and 12 g / L concentrations from a control solution of 2.2 g / L on growth and nutrition. The high mortality 100 % occurs during the first 24 hours at 8 and 12 g / L solution respectively. No fish mortality occurred at the treatment of 4 and 6 g / L during the same period. Statistical analysis of final weight, weight increase, daily growth rate, specific growth rate and relative growth rate showed no significant differences (P>0.05) between treatment 4 g / L and the control, but the treatment of 6 g / L exhibited significant different (P<0.05) with the control. The values of food intake for the body weight reached 3.59, 3.01 and 2.39 % for the treatments control, 4 g / L and 6 g / L respectively, with significant difference (P<0.05).

Gattan (Barbus xanthopterus Heckel) was artificially propagated in marine science center fish hatchery- University of Basrah, During Spring 2009. The brooders were collected from Al-Huwaizah Marsh (which were bring in to the hatchery directly) and Al-Therthar reservoir (which were reared in earthen ponds). The efforts to collect brooders from AlKut dam were failed, because of water shortage. The brooders ranged between 1500-6500 gr in weight and II-V year age. The gonads of AlHuwaizah marsh brooders were in good maturity stage, The GSI was ranged between 3.66-11.03%, and in ripe maturity stage, while the brooder's gonads of Al-Therthar reservoir were in developing stage, with GSI ranged between 1.1-1.3 %, and this result was agreed with the previous studies. "Aquacalm" substance was used for sedation; it was found that the best concentration for the sedation of Gattan was 1 ppm. The best treatment for the induced spawning of Gattan was the Carp pituitary gland extract (CPG), with a dosage of 6 mg/ kg, in two injections, each with 3 mg/kg, with 12 h interval. Two fishes from AlTherthar reservoir were responding to this treatment, with weight of 1750 and 1500g. 350 g of good quality eggs was obtained from the first fish. All the males give small quantity of milt the milt was added to the eggs without water for mixing. Then the eggs were covered with water for. Fertilization rate was 88%. The fertilized eggs washed with water only, from brooders rearing tank for 20min. Then incubated in Zoug jars with a rate off 70 g / jar, incubation temperature ranged between 22- 24°C. The hatching completed after 72 h, with 80 % hatching rate. The larvae start feeding after three days; it reached weight of 5.3 ± 0.80 during the first ten days. The larvae were reared in floating cages. The daily growth was 1.94 mg during the 21 days of rearing. During this period it reached a weight of 48 mg and 23 mm in length.

Effect of different levels of poultry offal concentrate (POC) and soybean meal (SM) on the growth rates of common carp larvae Cyprinus carpio had been studied, 360 larvae were distributed in 9 plastic 10 liter containers divided to three treatments with three replicates for each one, 40 larvae were put in every replicate (10 larvae \ L), the larvae were fed three diets for 35 days, the diets percentage were (25:75), (50:50) and (75:25) from (POC) and (SM) respectively. The body weight, specific growth rate, relative growth rate, feed conversion rate and survival rate were measured, it has been found that the best survival rate, relative growth rate, specific growth rate and feed conversion rate was in the 2nd treatment, it was 82 %, (77.9 ±1.22) %, (1.65 ±0.021) % and 3.0±0.1 respectively, there was a significant differences (P<0.05) between the different feeding treatments.

Samples of Rotifera genus Brachionus were collected from Al-Barka and Al-Nagara region in AlHammar Marsh, South of Iraq. Remarks on the taxonomy were notes on 6 species of the genus and a monthly density of each species were recorded during the study period from Feb-2006 to Jan-2007.The highest value of total density was 2.78 ind /l recorded in May -2006, whereas the lowest value was 0.01 ind /l and reported in March-2006.