الفهرس 
Arabic summary
gross anatomyOnly 14 pages are availabe for public view
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Abstract
Some aspects of the biology and the morphology of Bagrus bayad were studied.
1. The feeding habits of the young and mature specimens were studied by examining the stomach contents and identifying of the different items of food.
2. The variation of the feeding habits of the young and mature adults during the different seasons was determined.
3. The intensity of feeding of the whole sample was recorded during the different seasons.
4. The digestibility of the different food items was observed by the rectal contents.
5. It is concluded that Bagrus bayad is a carnivorous fish. It feeds mainly on the immature stages of water and aerial insects during the young stages but depends mainly on fish diet the adult stage.
6. The intensity of feeding increases during spring and summer and decreases during winter.
7. The morphology and the histology of the digestive system were studied.
8. The mucosae of the mouth pharynx and oesophagus are characterized by the presence of giant cells which resemble the club cells of the skin of siluroids.
9. The breeding and spawning were determined by the examination of the gonads throughout the year .It was found that the breeding season begins during May and ends by January. Spawning takes place during the period from August to January.
10.The fecundity was estimated by Stone’s method through the examination of 73 ripe females ,it was found to vary in the range between 10697 and 154200 ova.
11. Generally the fecundity was found to be directly proportional to the length and weight of the specimen.
12. The average diameter of the ova varied between 0.62 to 1.03 mm.
13. The histology of the testis and the ovary was studied in the resting and the ripe specimens.