the influence of environmental parameters on the abundance of monkey goby, neogobius pallasi (berg, 1916), in kaboodval and shirabad streams, golestan province, iran

The aim of this study was to determine the influence of environmental parameters onthe abundance of monkey goby neogobius pallasi. a total of 526 and 163 individuals ofmonkey goby specimens were caught by electroshocker in the kaboodval and shirabad streams, respectively. the ranges of total length of the specimens in kaboodval and shirabad streams were respectively 22-137.55 mm and 32.64-137.97 mm. all the specimens of both streams belonged to the 5th age group (0^+-4^+). the morphological, hydrological, biological and physicochemical parameters were investigated in both streams. the results showed that the hydrological parameters and vegetation coverage in the kaboodval stream and also, water velocity and depth in the shirabad stream had significant relationship with the monkey goby abundances (p<0.05). there was no significant difference between physicochemical parameters and monkey goby abundances in both streams. moreover, the positive effect of elevation and negative influence of distance to road were observed but they were not significant.