فراواني و تنوع لارو ماهيان در آبهاي ايراني خليج گواتر

Abundance & diversity of Ichthyoplankton in the Gwatar bay of Iranian water

Abundance and diversity of the fish larva was carried out seasonally at 5 sampling sites during 2005 (post monsoon) - 2006 (pre monsoon) in Gwatar bay of Sistan and Baluchestan provience. The samples were collected by Bongo with 335m mesh size, The vertical sampling was from bottom to surface, environmental factors such as temperature, salinity, pH and glassiness was measure. In the study, 386 specimens were collected at 3 stages preflexion, postflexion and flexion belonging to 11 families of these 9 specimens of the preflexion stages was not identified. Gobiidae (72%) , Clupeidae (10%), Engraulididae (7%) were the most dominant families respetively, and these were formed 89% of the total abundance of fish larva. Gobiidae showed significant different (P<0.01) with other families. majority of the identified larval samples were found to be typical neritic and tidal zone faunas inhabiting soft and muddy sea bed. Fish larvae were present during all seasons in the sampling area. The high abundance of the ichthyoplankton was in winther and low abundance was in atum. comparison of the site sampling, station 3 and station 5 showed the maximum abundance of the fish larvae. On the basis of Shannon diversity index, maximum diversity was in station 1 (3.02) and minimum in station 3 (1.28). Absolute abundance of fish larvae showed significant difference in different seasons (P<0.05) but species diversity showed no significant different (P>0.05). Diversity and abundance showed also no significant difference between different sites (P>0.05), this could be due to homogeneity of biological conditions in the area, as maximum abundance of some families depend on their habitat conditions.