The ceiling of the midbrain has a couple of optic lobes which are prominent and used as an optic center that reflex what it receives from eye retina fibers. The histology of optic tectum has been studied in Iraqi water snake natrix tesselata tesselata . It was found that the number of optic tectum were seven main strata organized from the outside to the inside as follows : the stratum zonula (SZ), the stratum opticum (SO), the stratum fibrosum et griseum superficialis (SFGS), the stratum griseum central (SGC), the stratum album central (SAC), the stratum griseum periventricular (SGP), and the stratum album periventricular (SAP). the three last strata consider deep layers on the optic tectum It was noticed that the thinnest strata was the fi

  A histological study was conducted to examine the structure of optic tectum in Hemidactylus flaviviridis. The results showed that the optic tectum consists of fourteen strata organized in three zones. The deep zone which extends from the first stratum (around optic ventricle) to the fifth stratum. The medium zone comprises the sixth & seventh strata, which represent the center of optic tectum. The superficial zone which extends from the eighth stratum to the fourteenth stratum and forms the retino recipient region.         The strata of deep zone are called the Stratum Griseum et Periventricular ( SGAP ) , the sixth stratum  is  called the Stratum Album Central ( SAC ) and&nbsp

The morphological description of inner ear in Barbus luteus have been investigated.
The results of the present study revealed that the fish under investigation has a pair of
inner ears which are embedded in two otic capsules of the skull. The inner ear contains two
main structures, the first is the Osseous Labyrinth (OL), and the second is the Membranous
Labyrinth (ML).
Both of (OL) and (ML) consist of three semicircular canal (SCC). These are anterior,
posterior and horizontal semicircular canals (ASCC, PSCC and HSCC).
The (OL) contains three chambers while the (ML) contains saccular structures which
are called otoliths organs represented by utriculus (U), sacculus (S) and lagena (L). Each of
the saccu

    Two local fish Himri Carasobarbus luteus (Heckel, 1843)  and Hishni Liza abu (Heckel, 1843) were stained with Alizarin Red and featured some anatomical qualities which cleared the difference of the muscular and skeletal fabric for each fish. Since clear Histologic differences appeared in these two species, it was intended from this study the possibility of adopting a diagnosis between local fish species by staining bones and tissues.

The female Shabout were collected as samples from Dijla river in Baghdad. The oocyte developmental stages were divided in to nine stages, based on nucleus structure , cellular inclusions and ovarian follicle structure ,they are:-( Oogonia stage , Early Perinucleolar Stage , Advanced Perinucleolar Stage , Cortical Alveoli Stage , Primary Yolk Stage , Secondary Yolk Stage , Tertiary Yolk Stage , Migratory Nucleus Stage , Hydration Stage(

This paper describes the first occurrence of the monogenetic trematode Silurodiscoides
mediacanthus (Achmerow, 1952) in Iraq from gills of the cyprinid fish Barbus luteus from
Diyala river, Diyala province, Iraq. The description and measurements of this parasite were
given. In addition, key for the identification of the three species of Silurodiscoides, so far
recorded from freshwater fishes of Iraq, is included.

The morphological description and histological structure of the

olfactory     organ     of    Parasilurus     triostegus     (Heckel)     have    been

investigated. The olfactory organ situated on the dorsal surface of the

head infront of the eye.

It  is  represented   by  elongated  olfactory  sac,  in  which  the

olfactory Lamellae arranged as Rosette- like pattern .

The olfactory sac connected with the olfactory bulb by short olfactory nerve. The olfactory bulb which situated near the olfactory sac connected wi

  The study includes histological structure of  digestive tract of  Liza abu , Anatomical results found that the digestive tract occupied the largest part of  abdominal cavity ,  the mean gut length was (45.5) cm and relative gut length was (2.9) .  esophagus was a muscular tube length (1.5) cm , esophagus wall containing longitudinal  straight unbranched folds numbering (9) . Histological study  results found that the esophagus composed of four tunica : mucosa , submucosa , muscularis and serosa . The results found that the mucosa consists of three layers : epithelium , lamina propria and muscularis mucosa . The epithelial layer was stratified squamous epithelium thickness (139.1) µ containing

  The study current included histological structure of stomach of Liza abu , anatomical results found that stomach represent the expander non-convoluted part of gastrointestinal tract it is located between the end of the esophagus and the beginning of the intestine , the average length of stomach was (1.5) cm , composed of two parts : cardiac stomach which is represent the anterior part and be thin- walled , the other part was pyloric stomach or gizzard and the walls were thick . The internal surface of cardiac and pyloric stomach contain longitudinal folds numbering (7), folds branching to finger shape structures extend inside the lumen . Histological study showed that stomach wall composed of three main histological layers : mucos