Distribution of red belly tilapia Coptodon zillii (Gervais, 1848) larvae in Shatt Al-Arab River and East Hammar marsh, Iraq


The larvae of Coptodon zillii were surveyed in Shatt Al-Arab River and East Hammar marsh from January 2015 to December 2015. A total of 127 C. zillii larvae were collected from three stations. The highest number of C. zillii larvae was 78 recorded at station 1 in East Hammar marsh (Mansoury), comprised 61.41% of the total fish larvae collected, and the lowest number (23) was from station 3 in Shatt Al-Arab River near Abu Al-Khaseeb, comprised 18.11% of the total fish larvae collected. C. zillii larvae were found in the study regions from April to October. The peak of abundance was 22.8 larvae/10m² during July at station 1. The lower abundance of larvae was 0.7 larvae/10m² in June at station 2 at the confluence of the Garmat Ali River with Shatt Al-Arab River. Water temperatures in the three sampling stations were similar and ranged from 12°C in December to 32 °C in July. Salinity in station 1 ranged from 1.2‰ in August to 2‰ in June while in station 2 it ranged from 1.03‰ in October to 2.8‰ in July and in the station 3 ranged from 2.7‰ in April to 6.1‰ in December during the study period. Positive correlation was shown between water temperature and salinity in all stations with the number and abundance of C. zillii larvae. The results indicated that the Shatt Al-Arab River and East Hammar marsh are spawning grounds for this species.