Mesopotamian Journal of Marine Science

The early development of common carp (Cyprinus carpio L., 1758) was studied from fertilizing until juvenile stage. The series developmental staging was done using morphological characteristics. Results identified eight main periods of embryogenesis: zygote, morula, blastula, gastrula, neurella, segmentation, pharyngula and hatching period. Results also identified and described nine larval development stages: hatching larva stage, rudimentary - pectoral fin and gill arch stage, melanoid-eye with gas bladder emergence stage, one chamber gas bladder with yolk absorption stage, two chamber gas bladder stage, pelvic fin bud with dorsal fin formation stage, anal-caudal and pelvic fin formation stage, squamation stage and juvenile stage. Hatching occurred at 38h after egg fertilization. The fertilized egg was spherical, yellowish, transparent and 2.5 mm in diameter. The transition from larva to juvenile occurred in 30 days.

This study was carried out during the period from Winter 2010 to Winter 2011 to evaluate the concentrations of heavy metals (Fe, Co, Ni, Cu and Pb) in tissues of commercially valuable coastal fishes (Talang Queenfish, Scomberoides commersonianus) from Iraqi coastal areas around the Faw Peninsula which receives petrochemical wastes. Thus, it is important to identify the extent of concentrations of heavy metals in fish and consider potential impacts on the food chain and risks to human health. Fe had the highest level of accumulation in the four tissues examined (gill, muscle, liver and gonad) of S. commersonianus whilst Pb had the lowest (p < 0.05). The order of the heavy metal concentrations in the gills, muscles, liver and gonad tissues of S. commersonianus across all the stations was Fe (198.27 μg/g) > Co (21.07 μg/g) > Cu (7.89 μg/g) > Ni (5.43 μg/g) > Pb (1.85 μg/g). This study suggests that additional measures must be taken to monitor waste and ambient water quality, and to prevent contamination of fish for human consumption.

In the present study, abundance and distribution of fauna in the sub surface sediments of the eight stations, Abo Flos, Ras Al-Besha, Khor Al-Umaya, Khor Shitana, Umm Qaser, Khor Al-Zubair, Kutaiban and Al-Faw were investigated. The stations selected for the present study were located at the southern region of Mesopotamia plain in Iraq. A reconnaissance survey in the study area showed the distribution of many marine species in the coastal areas (Khor Shitana, Umm Qaser, Khor Al-Zubair and Al-Faw). They were affected by the marine water areas with few effects of tidal flat and current waves. The affinities of the studied species are coming from the Indian Ocean towards the Red sea and the Arabian Gulf. The salinity and texture of sediment are the main factors that control the ecology and distribution of recent fauna. The soil texture for eight stations are sandy silt, clayey silt, silt, sandy silt and mud respectively.

The present study was conducted from December 2013 to November 2014 to investigate the reproductive features of Himri Carasobarbus luteus in the Northern reaches of Shatt Al-Arab river in Southern Iraq. The samples were collected using seine, gill, cast nets as well as electrofishing. A total of 351 specimens from himri were caught but only mature individuals were chosen to estimate the absolute and relative fecundity and egg diameters. The results of the present research revealed that the highest GSI values were recorded in male and female (4.63 and 11.99) during the April month. Absolute fecundity was increased with length, weight and gonads weight, and it was ranged as 2098 eggs for 131 mm total length and 35 g weight to 14147 eggs for 209 mm total length and 131 g weight. Relationship between length, weight and reproductive parameters were highly significant. A highest relative condition factor of females (1.24) was calculated in March 2014.

High-resolution Side Scan Sonar data, under-water observation (video and photograph) and bottom samples (rocks and sediments) were integrated to map the seafloor of the Palinurus shoal which is one of the submerged shoal site in the Iraqi territorial marine, Northwest region of the Arabian Gulf. The Side Scan Sonar field survey was carried out along with eight parallel profile extending in SE-NW direction, at a length of 2.8 km for each line. Four backscatter patterns were mapped within the study area. The pattern reflects various seafloor lithology. The average depth of sea bottom was determined at 7 - 10 m. Coral Reefs were mainly found at two parts of the shoal site in the formed assemblages and sporadic in central and northern parts of the site respectively. These coral take different shapes, sizes and colors. Also, they are live in some places and dead in others.

In the present study, the physical and chemical properties of some coastal lagoons which include water temperature, salinity pH, dissolved oxygen, phosphate, nitrate, nitrite and ammonia were evaluated to study their environmental status. The water temperature was high in summer and it reached about 28.07 °C at Kalige Um-Alshawsh inlet and then it was drop to 14.39 °C at the Gulf of Bomba. Salinity was found to be high (41.95 ppt) in Autumn at the Gulf of Bomba and less salinity value (38.20 ppt) was recorded in Summer at Marsa El-Katayta. The highest concentration of dissolved oxygen was recorded as 9.59 ppm in Winter at Um Alshawsh inlet and a lower concentration recorded was 5.69 ppm in Summer and was measured at the same station. Highest pH value (8.62) was recorded in Summer at Um Alshawsh inlet while the lower value was observed as 7.84 in Winter at the Gulf of Bomba. Higher value of phosphate was recorded as 2.152 µg-at.P-PO43-.l-1 in Summer at the Gulf of Bomba and a lower concentration of phosphate was recorded as 0.369 µg-at.P-PO43-.l-1. Higher value of nitrate was observed as 4.795 µg-at.N-NO3-.l-1 in Summer at Marsa El-Katayta and the lower value was recorded as 0.577 µg-at.N-NO3-.l-1 in winter at port Bordia, while the higher value for nitrite was recorded as 0.741 µg-at.N-NO2-.l-1in Summer at Um El-Shows inlet and the lower value was observed as 0.242 µg-at.N-NO2-.l-1at the same station. Higher ammonia value (1.044 µg-at.N.l-1) was noticed in the Autumn season at the Gulf of Bomba where non detectable level had been noticed in Summer season at Marsa El-Katayta. The results of the present research exhibited the basic addition to understand these environmental conditions for future activities such as the possibility to exploit, develop and to predict the environmental variables.

The present study describes the fish assemblages in Khor Al-Zubair lagoon which was located in North West region of Arabian Gulf. The present research was carried out from August 2012 to July 2013 by using various nets. Two environmental factors viz., temperature and salinity were measured during the study period. The total number of individuals collected was 2964. The highest number (513) was recorded in August month and the lowest number (31) was observed in January. Thirty eight species belonging to 28 families of Osteichthyes and two species of Chondrichthyes (Aetobatus narinari and Chiloseyllium grisum) were collected in the region, Mastacemblus mastacembelus and Tilapia zillii were recorded for the first time. The highest number of species (19) was recorded in September while the lowest (8) was noticed in the February month. Three species viz., Thryssa whiteheadi, Liza klunzingeri and L. subviridis formed 43.65 % of the total fish catch. The overall value of diversity index (H), Eveness (D) and Richness (J) were 2.5, 3.4 and 0.8 respectively.

In the present study, the morph-histological characterization of the brain development in common carp was studied in Basrah, Southern Iraq, by examining the several samples of eggs and larvae of Common carp Cyprinus carpio. The temperature of the water in incubators was 25 -27 ˚C and the incubation of eggs were carried out for 38 hour. Morphologically, neural stage was emerged after eight hours of incubation with continuation of epiboly processes Brain was progressively differentiated into three main parts namely forebrain, midbrain and hindbrain. Forebrain was differentiated into telencephalon and diencephalon. Optic primordial was appeared after 12 hours of fertilization in a form of evagination from both sides of the forebrain and slightly oval elongated and then characterized optic vesicle, then the lens was appeared. Hindbrain was clearly differentiated and neuromerse was marked after 22 hours of fertilization. Histologically, the brain at the age of 24 hours was composed of a mass of undifferentiated neuroectoderm, whilst at the age of 28 hours appeared more differentiated with clarity a cerebral hemisphere on both sides of the forebrain and it was a mass of undifferentiated neuron cells. Gradually, the brain parts were completed with a differentiation of several layers until the age of 20 days after hatching.