Iraqi Journal of Aquaculture

In the study we cultured the shrimp P. vannamei (initial
weight 0.0004 g) under laboratory conditions in marine science
center and using three types of food. These were life food
(Artemia nauplii), artificial died and mixed food (Artemia
nauplii and artificial died). The highest average weight were
achieved when feeding on the mixed feed (1.210 g), while, lower
values achieved when fed on artificial diets 0.220 g. There are
significant differences (P<0.05) between these three food types.
A similar results were obtained for growth in terms of length,
the highest average length of larvae after six weeks was
achieved when fed on the mixed food (36.58 mm), comparing
with these larvae fed on Artemia and artificial feed were 31.11
and 18.72 mm respectively, and there are difference
significantly too (P < 0.05) between the three food types.
The highest average weight increment was recorded during
the sixth week with mixed food it was 0.55 g, compared with
0.23g and 0.12 g for Artemia and artificial diets respectively.
The higher survival rates after sixth week were calculated for
the three treatments, the high survival in larvae fed on Artemia
it was 90.58 %, while, these fed on mixed food and artificial diet
it was 85.62% and 73.24 % respectively.

Concentrations of cadmium, cobalt, cupper, iron,
manganese and nickel were determined in four organs
(liver, gills, ovaries and muscles) of Acanthopagrus latus,
which collected from Iraqi marine waters during the
period between November 2010 and October 2011. Heavy
metals have been determined by means of Atomic
Absorption Spectrophotometry. The fish average weight
was 61.2 g and the average length was 144 mm. Nickel
showed the highest values in liver, gills and muscles
during spring (201.19, 190.00 and 148.00 µg/gm dry
weight), respectively. While cobalt showed the lower
value (1.12 µg/gm dry weights) in the liver and cadmium
showed its lower value (1.23 µg/gm dry weights) in the
gills during winter. Muscles showed constant levels of
heavy metals, it showed the lower values (not detected)
during winter. Ovaries showed high levels for all heavy
metals during spring, but its value still instable during the
other seasons. This study showed that the concentration
of heavy metals distributed in the organs was as follows:
liver > gills > muscles > ovaries, while the heavy metals
concentration had been distributed during the seasons as
follow: winter > spring > autumn > summer.

This study was performed on the Gymnura altavela
(Linnaeus, 1758), during the period between July 2011- June
2012, in the Syrian coast. A total of 58 examined samples (26
males and 32 females) showed that the size which female
start maturation at 701 mm of disk width (DW), while the
males start maturation at 682 mm. Females were always
larger than males, the largest female and male were 1342
mm, 893 mm (DW), and the total weigh were (20170 g, 5071
g) respectively. G. altavela is a non-placental ovoviviparous
species. The female has two ovaries, the left one is active, and
the right one is atrophic. Female gestate the embryos in two
uteri. Gestation could continue 9-12 months. Ovulation
occurs at end of summer and at beginning of autumn,
parturition occurs at end of spring and beginning of summer.
One reproductive cycle occurs per year. Average of disk
width and weight of fully-developed fetuses were 290 mm
and 246 g. respectively. Fecundity ranges one to four
newborns per litter, embryos and fetuses are symmetrically
distributed in two uteruses, with increasing to left one, the
ratio was 1:1.2, average of uterine fecundity was (3), average
of ovarian fecundity was (6.3).

The study included 144 fishes in Lake of 16 Tishreen Dam for
detecting the infection with parasitic Protozoans, and determine
the distribution rate. Fishes were collected randomly once a
month, during the period from 22/12/2011 until 22/12/2012.
Collected fishes samples were belonged to the following species:
Cyprinus carpio L., Varicorhinus damascinus, Garra rufa,
Tilapia zillii, and Liza abu. T. zillii was the most prevalent in the
lake of 16 Tishreen Dam.
The study has shown presence of three species of parasitic
Protozoans on the Skin, Fins and Gills continuously. Trichodina
sp. was the most distributed one with a rate of (34.03%) then
Ichthyophthirius multifiliis (15.97 %) then Chilodonella cyprini
( 2.78 %). The infection rate of T. zillii with parasitic Protozoans
was the highest 54.46 %, Trichodina sp. was 42.57 % ( in
Summer 62.26 %), and C. cyprini 3.96 %,( in Summer 7.55 %)
whereby the infection rate with I. multifiliis was 19.80 %( in
Autumn 33.33 %).

This study reviewed the validity of using the scales of
Hilsa Shad (Tenualosa ilisha) and other migratory
species as a tool to estimate age, growth, maturity
schedule and migration. Hilsa Shad scales were used long
ago, and proved in several studies. Most of these studies
showed that scales could give valuable information,
which could be used as benchmarks in the study of
fisheries and plans for future successful management
policies. Bt it needs Patience and precision for the
extraction of these information, because of difficulties in
reading these scales. The work need to study the
sufficient number of scales and practice, to be easily. As a
result, this study will open doors that were closed for
decades to set new migration study tools for Hilsa Shad
in Iraq.

The present study appear the concentration, source and origin of petroleum
hydrocarbons in sediment core of two station of Hor Al- Azim at Hor Al –
Huwaiza ,total hydrocarbon measurement by spectroflurometer were in these
sediment cores. Higher concentration (20.5 µg/g) dry weight at depthe (0-5) cm
in Azim (I) while lower conceatrations (1.5) µg/g dry weight at depth (100-105)
cm, in Al-Azim (II) higher conceantration was (17.52) µg/g at (0-5) cm depth
and lower concentration (1.73) µg/g at depth (80 -85) cm .The higher percentage
for total organic carbon (TOC%) appear in Al-Azim (I) (3.52)% at depth (0-5) cm
while lower percentage were (0.15)% at depth (90-95) cm . In Al-Azim (II)
higher percentage were (4.2)% at depth (0-5) while lower percentage (0.72)% at
depth (80-85) cm and we well do to analysis grain size at the sediment were
mainly muddy silt with low sand in addition to ports sheel from mollusca shell
and disintegrate vegetation for both of the tow core.