Volume 7, Issue 2, Autumn 2012, Page 102-188
Accumulation, release, and depuration of crude oil-in water emulsions by the bivalve Corbicula fluminalis Müller (Molluscs: Bivalia:Eulamellibranchiata: Corbiculidae) from Shatt Al-Arab river,Basrah, Iraq
Volume 7, Issue 2, Pages 102-118
The bivalve C. fluminalis was exposed to a single doses of sublethal concentrations (20,
60, and 120 ppm) of Basrah regular crude oil-in water emulsions for a month period, under the laboratory conditions. The pattern of accumulation and release of petroleum hydrocarbons, the depuration time (biological half-life, TB50), and the mechanisms of transport of petroleum hydrocarbons into the bivalve were determined. The bivalve accumulated the highest amount of petroleum hydrocarbons during the first week of exposure to crude oil emulsions. The accumulated petroleum hydrocarbons decreased each week as the petroleum hydrocarbons content of the exposure water decreased. The capillary gas chromatography analysis revealed that the dominant petroleum hydrocarbons accumulated by the bivalve after the four weeks of exposure to crude oil emulsions were naphthalene, phenanthrene, C12, C13, and C14. The depletion of petroleum hydrocarbons from the exposure water, and the accumulation and release of petroleum hydrocarbons by the C. fluminalis involved formation a complex of mucus and crude oil by the bivalve. The depuration period was began when the bivalve was transferred to a clean river water for two weeks subsequent to the month exposure to crude oil emulsions. The accumulated petroleum hydrocarbons were rapidly, although incompletely released. At the end of the depuration period, the capillary gas chromatography analysis showed that the petroleum hydrocarbons retain in the bivalve was naphthalene. The biological half-life (TB50) for depuration of the bivalve calculated were 55 days, 14.5 days, and 18 days for 20 ppm, 60 ppm, and 120 ppm respectively.
Volume 7, Issue 2, Pages 119-125
The process of hybridization was carried out between female of Barbus xanthopterus X male of Barbus sharpeyi by artificial reproduction in Marine Science Center hatchery. Environmental factors (Temperature, salinity, dissolved oxygen, and pH) of the hatchery water were measured. The environmental factors within the optimum limits for the process of artificial breeding of these two species. The fertilized eggs were hatched and the larvae were reared inside the hatchery for six days. Later the hybrid larvae transferred to floating cages in the earthen pond, the initial larval weight was
5.2 mg. The rearing of hybrid larvae continued for 20 days and the average of final length was 20 mm
and average of final weight was 41mg.
Volume 7, Issue 2, Pages 126-136
Trace elements (cobalt, iron, nickel, manganese, copper and cadmium) were studied at three organs (muscles, liver and gills) of the body of fish, silver carp (Hypophthalmichthys molitrix) during the period from autumn 2009 to summer 2010. The concentrations of these elements were measured using Flame Atomic Absorption Spectrophotometry. Results showed that the trace elements (cobalt, iron, nickel, manganese, copper and cadmium) in muscles were ranged from ((ND (spring) to 5.54 (summer) ; 40.68 (winter) to 72.10 (summer) ; 55.23 (autumn) to 69.23 (summer) ; 3.12 (winter) to
5.72 (spring) ; ND (winter) to 14.34 (summer) ; 1.16 (autumn) to 2.89 (spring)) µ g/g dry weight, respectively. While in liver were ranged from ((5.22 (spring) to 16.71 (summer) ; 55.80 (winter) to
98.90 (autumn) ; 70.45 (winter) to 89.18 (autumn) ; 6.01 (summer) to 10.99 (spring) ; 20.10 (autumn) to 30.22 (summer) ; 6.50 (autumn) to 12.69 (summer)) µ g/g dry weight, respectively. Also, in gills were ranged from ((11.13 (spring) to 19.36 (summer) ; 50.50 (winter) to 83.91 (summer) ; 58.28 (summer) to 78.91 (winter) ; 7.00 (summer) to 13.62 (autumn) ; 11.30 (autumn) to 23.61 (summer) ;
8.51 (summer) to 10.22 (winter)) µ g/g dry weight, respectively. Generally, the concentrations of these elements in liver were higher than in muscles and gills. The trace elements concentration had been distributed during the seasons as follow: summer > spring > autumn > winter.
Volume 7, Issue 2, Pages 137-149
After extensively drained of Mesopotamian wetlands, southern Iraq in 1990s Ceratophyllum demersum L. reappeared as response to re-flooding. This investigation was conducted to study distribution of Ceratophyllum demersum in Al-Mashb marsh, Hor Al-Hammar, and the physical-chemical properties of its habitat, Water depth (WD), light penetration (LP), water temperature (WT), water salinity (Sal.), pH, dissolved oxygen (DO), calcium (Ca+2), magnesium (Mg+2), nitrite, nitrate, and phosphate were seasonally determined during 2008. Its vegetation cover percentage was 85 % with its peak in summer, while the lowest value was
35 % in winter. CANOCO ordination program (CCA) was used to analyze the data. Statistically, Positive relationships for WT, pH, Ca+2, Mg+2, nitrite, nitrate, and phosphate with the vegetation cover percentage were observed. However, negative relationships for Sal, WD, LP, and DO with the vegetation cover percentage were observed. Myriophyllum spicatum L. and Hydrilla verticillata (L.f.) Royle were recorded as associated species with C. demersum community in this study.
Volume 7, Issue 2, Pages 162-168
Phenol is one of the organic pollutants in various industrial wastewaters especially petrochemical and oil refining. Biological treatment is one of the considerable choices for removing of phenol from these wastewaters. Identification of effective microbial species is considered as one of the important priorities for bacteria producting biomass in order to achieve desirable kinetic of biological reactions. Basic purpose of this research is identification of phenol-degrading Pseudomonas putida by polymerase chain reaction (PCR) that has high speed and specificity . Amplification gene coding the N fragment in Pseudomonas putida-derived methyl phenol operon (DmpN gene) was used for specific identification of phenol-degrading Pseudomonas putida,According to the results of this study
7 of 10 isolated bacteria Pseudomonas putida showed a 199 bp PCR product by DmpN
Rotifers community structure and abundance along Shatt Al-Arab River from Garmmat Ali to Al- Fao, Southern Iraq
Volume 7, Issue 2, Pages 150-161
The Rotifers community along Shatt Al-Arab River was investigated during four seasons of 2006. 49 species belonging to 27 genera recorded. The genus Brachiouns the highest number of species (7) following by Monostyla and Trichocerca 4 each constituted and Keratella (3) species..
In general Brachionus calyciflorus and Keraktella valga were most frequent and dominant species. Within the five investigated sites, Al- Karoon station was characterized by highest rotifers density(369 ind./l) and Abu Al-Khaseeb station showed the less density ( 230 ind. / l ). However, summer was the period of highest densities. Diversity Indices for the five studied stations were calculated, the value ranged between 1.43 – 1.61 for Shannon – Weaver
index, 6.29 – 8.47 for richness index, and between 0.51 – 0.55 for uniformity index
Volume 7, Issue 2, Pages 169-188
Palynological features of the pollen grains of Dicots wetland plants of the Southern Marshlands of Iraq were studied. Forty nine species belong to twenty five families were investigated .The results showed that there were significant difference and high diversity in shape, size, ornamentation and apertures of the pollen grains of most genera and species studied. Most families and genera have their own characteristic pollen types. On the basis of ornamentation and apertural types, nineteen distinct pollen types were recognized. Pantoporate pollen grains were showed in several families such as Chenopodiaceae and Amaranthaceae. Most species contain three colpi as in Bacopa monniera, while Myriophyllum spicatum contains 4-5 clopi, but many species contained colp and pore as in most of Dicots species as in Compositae. Ornamentations were varied from psilate in the Utricularia australis to echinate in some species of Compositae.