It is reported on results of a trawls survey in 2011 to assess the amount of biomass and Catch Per Unit of Area (CPUA) and also to determine the distribution pattern of two main families of demersal fishes as one the most important and commercial fish species in the northwest of Persian Gulf. Samples were collected at a total 65 trawl stations selected a stratified random procedure. The catch rates of CPUA and biomass of two target fishes were estimated to be approximately 186.5 kg/nm2, 2476.8 tons for Haemulidae family and 130.8 kg/nm2 and 1737.6 tons for Sphyraenidae family, respectively. The highest value of CPUA of Haemulids was recorded in the east of the study area (stratum D, approximately 1097.4 kg/nm2) and the highest biomass was found in strata C & D. On the other hand, the highest CPUA and biomass were recorded in stratum C. It was concluded that strata C and D (namely from Dayer to Genaveh) contain the best fishing area from point of higher density and distribution of Haemulids and Sphyraenids in the covering area, and from point of depth distribution, they are found in depths less than 20 m and more than 30 m, respectively.
