Samples of Alburnus mossulensis were collected from the south part of Euphrates River, Chybaish, Iraq from November 2013 to October 2014 using electro fishing. The spawning period started in February according to GSI values and histological examination for gonads during spawning season. The results of histological examinations revealed that this species has a short spawning season and female ovaries contained different maturing stages of ova, and the maturation started from the post part of gonads according to the space noticed at the middle part of the ovary. Histological examination proved that testes also contain different maturation stages. Blood vessel penetrate lobules with few spermatocytes at the posterior part of the testes whereas the anterior part less mature with disappearing of spermatocytes.

Length-weight relationships of Brachirus Orientalis, in coastal areas of Faw, south of Iraq was carried out on January to December 2019. Total length were ranged from 15.3 to 42 cm for 193 collected specimens, weight ranging from 59.60 to 1123.65g. According to the length-weight correlations the b value was 3.021. This demonstrated that positive allometric growth for both sexes. Calculated values of condition factor were 1.02and 1.12 for male, female respectively that showed healthy condition of fish.Key words: Brachirus Orientalis, Length-weight relationships, condition factor, Iraq marine water.