DIVERSITY AND ABUNDANCE OF ICHTHYOPLANKTONS IN GOUATER AREA (COSTAL WATERS OF SISTAN & BALUCHISTAN PROVINCE)

Ichthyoplanktons were identified and their abundance was determined in Gouater Creek & Bay, north-west of Oman Sea. Sampling was carried out from October 2005 to September 2006 and specimens were collected from six stations using single ring plankton net with 333m mesh size. Stations including: close to coastal waters (1,2,4), into creek (5 and 6) and close to Bahookalat creek out flowing waters (station 3). Measurement of the environmental factors showed that an average depth 4m, transparency was 75cm, salinity 37.08 g/l, pH 8.19, water temperature 27.3oC for the study area. Totally, 585 specimens of diverse fish larval stages were collected in 20 sampling efforts with mean abundant of 11.682 numbers/10m2. A total of 11 fish families were identified in the samples in which the dominant families larvae were Gobiidae, Clupeidae and Engraulidae with mean abundant of 6.875, 2.465 and 0.733 numbers/10m2 respectively and the total abundance specimens of fish larvae were 86%. The most of the mean abundant fish larvae were observed in winter (27.712 numbers/10m2) and the least were recorded in autumn (3.724 numbers /10m2).
The larval stage of the specimens was mostly Preflexion (87%) that shows the area is a nursery ground for the species. No correlation was found between abundance and temperature and salinity. Comparison of abundance showed a significant difference between stations 1, 3 and 5 with stations 2, 4 and 6 and also, winter by other seasons. The difference in diversity from pre monsoon and post monsoon periods was significant (P>0.05).