عنوان مقاله [English]
In order to investigate the effect of environmental parameters such as water temperature, depth and width of rivers on biodiversity of macrobentose in Dalaki and Helle river (Boushehr Province), this research was developed. The research period was 14 months and it studied in seven sites. Maximum of biodiversity was observed in warm months and upstream sites. Biodiversity in downstream sites was much lower than upstream sites due to pollution rate entered from near cites to the river. The highest relative frequency of species (% 42) in site 1 belonged to Ephemeroptera order, but they were not observed in site 7. This frequency (% 34.8) belonged to Diptera order in site 7. The bottom structure was rocky in upstream and with a small steep to the river stuary to the smooth and sandy-lomy texture. The bottom structure had direct effect on biodiversity and species density.