ISSN: 1812-237X

Volume 13, Issue 2

Volume 13, Issue 2, Autumn 2016, Page 87-189

Water and Ionic Balance in Blue Tilapia Oreochromis aureus (Steindacher 1864)

Rafaa Abdul kareem Faris

Iraqi Journal of Aquaculture, Volume 13, Issue 2, Pages 87-108

This study was conducted to study the response of Blue Tilapia Oreochromis aureus to increasing salinity. Abrupt and gradual transfer to higher salinity was done to determine salinity tolerance and survival rates and was found that this fish tolerate the abrupt increasing in salinity between 1.5 – 20 g/l with Lc50 (20.44 g/l). Salinity tolerance increased with gradual increase in salinity as survival rate increased to 90% in salinity 30 g/l. Muscle and gut were used to investigate their role in water and ionic balance and was found that the water content in the muscle decrease with increasing salinity while it increase in the gut. The ionic content (Na+ and K+) increased in both muscle and gut with increasing salinity. This study showed the ability of this fish to change its osmoregulatory ability from hyperosmotic in fresh water to hyposmotic in salt water.

Impact of feeding levels on growth performance and food conversion of Acanthopagrus arabicus cultivated in concrete tanks at Basrah province

Abdul-Karim T. Yesser

Iraqi Journal of Aquaculture, Volume 13, Issue 2, Pages 109-124

This study was conducted to determine the effect of various feeding levels (3%, 5% and 7% body weight/ day) on final weight, weight gain, specific and daily growth rates as well as food conversion rate of Arabian yellowfin seabream Acanthopagrus arabicus. The experiment were executed in three concrete tanks (1m3) and extended 60 days. Results reveal significant differences (P>0.05) of final weight, weight gain, specific and daily growth rates at different feeding levels. Final weight attain 61.9, 63.25 and 61.65gm in feeding levels 3, 5, 7% body weight, respectively. The best food conversion rate showed that feed conversion rate value (4.677) was encountered at the feeding level 3% body weight followed by feeding ratio 5% (7.654) where as the lower food conversion rate (11.018) was found at the feeding level 7% body weight, Statistical analysis proved significant differences (P<0.05) in food conversion rates among selected feeding levels.

تأثير بعـض منظـمات النمو في استحثـاث الكالـس وتـضاعف نبات العـنطــــــران Alternanthera sessilis خارج الجسم الحي

Haleemah J. Al-Aradi

Iraqi Journal of Aquaculture, Volume 13, Issue 2, Pages 151-164

Propagation of Alternanthera Sessiels in vitro by callus induction through the culture of adventitious bud on MS medium supplemented with 2.4-D and NAA in 1.5mg/L, primary callus where transferred on MS medium supplemented with 0.5mg/L Benzyl Adenine (BA) and 0.5mg/L Kinetin (Kin) for induction Adventitious shoot, somatic embryos appeared when primary callus transferred to free hormones MS medium, Effects of cytokinins in direct organogenesis with various concentration was also examined, the fourth treatment 1mg /L Kin+1mg/L BA give significant Increase , and scored the highest mean of shoot number 12 shoot. Also fourth treatment caused significant increase and gave highest mean of shoot length 5.33cm, while no significant different was appeared between the fourth treatment and 1mg/L Kin in the number of vegetative bud. Fourth treatment also scored significant increased in the number of flower and give 5.33 flower/node, Direct and indirect regenerated shoot were transferred to half strength MS medium supplemented with 0.5 mg /L NAA+ 0.5 mg/L IBA for root induction, plantlet were transferred to water field after successful acclimatization.

Studies of Some Physical Properties of the extracted gelatin from Cynoglossus bilineatus skin

Ameer A. Mohammed

Iraqi Journal of Aquaculture, Volume 13, Issue 2, Pages 165-178

The study included extracting of gelatin from the fish`s skin Cynoglossus bilineatus using acid and alkaline pretreatment the chemical analysis of the experiment fishes skin shows that the extracted gelatin was 11.7% for yield, 85.7% for protein, 0.84% for fat , 0.65% for ash and 12.81% moisture. The physical properties of extracted gelatin such as melting point was 25.3 °C, setting points 21.8°C and 112 Sc. While the relatively viscosity was 2.5 cP, the result shows that the extracted gelatin have an ability to gelation in all concentrations, the emulsifying property increased with increasing of the concentration of the sample, the extracted gelatin have a good sensory properties with a pale Yellow color and less fish smell acceptable.

Distribution and Composition of Benthic-Invertebrate Community at Fish Floating Cages in Tigris River Before Al- Kut Barrier/ Wasit Province, Iraq

Aseel G. Radhiy

Iraqi Journal of Aquaculture, Volume 13, Issue 2, Pages 179-189

Seasonal study was done for the distribution and composition of benthic invertebrate community in three selected sites (S1, S2 and S3) near a fish floating cages in Tigris river before Al-Kut Barrier south Baghdad, during the period from January to December 2014. Some of water quality parameters were measured as following: temperature ranged from 14°C in winter to 32 °C in summer, dissolved oxygen from 5.2 in summer and 9.8 mg/l in winter, pH values from 7.5 to 7.8, salinity from 0.5 in winter to 0.73 mlg/l in summer and water turbidity from 250 in spring to 900 NTU in autumn. The river bottom of study area was clay loan, silt clay, clay loan and clay for sites S1, S2 and S3 respectively. A total of 19 benthic fauna species were identified. Of these 8, 6, 3, and 2 species belonged to Arthropod, Oligochaet, Mollusca and Nematode respectively. There were significant differences shown at S2 (inside cages) for the organic matter 4.7%, and for organic carbon 2.74%, 19 species, the abundance was 813.4 ind/ m2 and benthic biodiversity was 2.86, compared with S1 and S3. Also, S2 was shown the dominance for Arthropod: Insect (46.6%), followed by Oligochate, Mollusca and Nematode (32.9%, 16.5% and 4%) respectively of the total benthic invertebrate density. The results shown increment in benthic invertebrate density and biodiversity inside cages (site S2) compared with the other two sites before and after cages respectively.