Comparative study of fish larval communities in north and south part of Shatt al-Arab River

Abstract EN

Ichthyoplankton sampling was conducted at two stations in north and south part of Shatt Al-Arab River, during January to December 2012.

A total of 2709 fish larvae were collected using conical plankton net (mesh size 300μm).

Five families (Mugilidae, Cyprinodontidae and Cyprinidae, Cichlidae, and Clupidae) of fish larvae were identified at Station1, while station 2 eight families (Gobiidae, Engraulidae, Sciaenidae, Soleidae, Clupeidae, Polynemidae, Bothidae and Cynoglossidae) of fish larvae were identified.

The highest abundance of fish larvae occurred in May (145.17 larvae/10m²) at station 1, but station 2 in March(67.46 larvae/10m²).Water temperature showed a significant positive correlations with the number of fishes larvae families (r =0.664, r= o.830, p < 0.05 respectively) and with the total abundance of fish larvae at stations 1and 2 (r = 0.315, r= 0.470, p < 0.05 respectively).

The salinity showed negative correlations with number of fishes larvae families and with abundance at station 1(r = -0.165, r = -0.700,p < 0.05 respectively), station 2 showed a significant positive correlations(r = 0.894,0.520, r= p < 0.05 respectively).

Ecological indices were as follows: The highest value of diversity was in May (0.32) at station 1, while stations 2 in September (0.82), recorded highest evenness (0.42) in September at station 1, but (0.53) in October at station 2, and a peak of richness was apparent at station 1 during June (0.76), station 2 the highest value was (0.99) recorded in April.

It seems that the lower reaches of Shatt Al-Arab River more diversity comparative with upper reaches of Shatt Al-Arab River, and plays a role as a spawning, feeding and nursery ground for fish larvae of freshwater and estuary species.