Some Biological Aspects of Al - Shabbot Arabibarbus grypus (Heckel, 1843) in Al-Diwanyia River, Middle of Iraq

Abstract

      Some biological characteristics of shabbot, Arabibarbus grypus (Heckel, 1843) in the Al-Diwaniya River, middle of Iraq were studied from October 2016 to September 2017. Water temperature ranged from 10.2oC in March to 32.8oC in August. A total of 853 fish were caught by seine, gill and cast nets and electro-fishing. A. grypus constituted about 6.27% of the total fish catch. The length-weight relationship was W=0.021*L2.7548 revealing an allometric growth. The mean relative condition factor was 0.91. Five age groups wore recorded and their mean total lengths were 20.2, 32.0, 39.0, 43.9 and 48.4 cm, respectively. The growth model of the species was  Lt= 58 [1-e -0.39 (t-0.313)]. The growth performance index (Φ) of A. grypus was computed as 3.11. The study declares that the species is a omnivore, feeding mainly on aquatic plants, insects, algae and detritus. The overall sex ratio (female: male) was 1.47:1. The highest values of gonado- somatic index (GSI) were 4.20 for female and 1.78 for males in April. The fecundity of the species ranged from 75600 to 124200 eggs.