فهرست مطالب ashkan azhdari

In this study, the relationship between water physicochemical parameters (sampling of water and soil) and Babylon snail biomass was done by sampling from four fishing grounds of this species in the north of the Oman Sea including Pasabandar, Breis, Pozm, and Konarak from September 2021 to September 2022 by circular cages. The average values of different physicochemical parameters (pH, salinity, turbidity, TOM, dissolved oxygen, and sand and silt) and different nutrients (nitrate, phosphate, ammonia, and nitrite) in the before and after seasons (monsoon) did not show a significant difference (p>0.05) through one-way variance analysis (between several periods) comparison of averages. Temperature and silt parameters from different seasons (before and after monsoon) had significant differences (p<0.05). Multi-layer artificial neural network was used for the correlation among the snail biomass, physicochemical parameters, and water nutrients and it showed that Temperatures and Nitrite were the most impact parameters on (snail biomass). From September to November, the highest catch rate was observed and it was the main season of Babylon snail fishing in Sistan and Baluchistan region due to the decrease in the water temperature and increase in the nitrite content. This study can be considered for fishing sustainability, basic management in exploitation, and a better understanding of the biological and demographic characteristics of this snail species.

Babylonia spirata is one of the important commercial oyster species in the world. The ecological basis of the habitats of this mollusk in the coastal waters and in the areas of the continental plateau is a significant help to fishermen and operators. Therefore, to identify the ecological characteristics of the Babylon Sea snail habitat in the northern waters of the Oman Sea, water sampling was done to determine temperature, pH, salinity, dissolved oxygen, nutrients, turbidity, and sediment, the total organic matter and the type of substrate, Babylon species to determine CPUE was done monthly from September 2021 to May 2022. The results showed that the average water temperature during the study period was 27.79°C in Konarak, 26.99 in Pezam, and 28.5 in Pasabandar and Bris. The average salinity in Kanarak, Pozem, Bris, and Pasbandar stations were 39.33, 26.99, 39.25, and 39.25 g/L, turbidity 5.48, 2.5, 7.25 and 7.25 FTU, acidity 8.25, 8.22, 8.18 and 8.18, DO 6.6, 7.06, 6.97 and 6.97 mg/l, nitrate 1.35, 1.16, 1.11 and 1.11 mg/l, nitrite 0.04, 0.02, 0.055 and 0.055 mg/l, ammonia 0.05, 0.19, 0.01 and 0.01 mg/liter,  phosphate 0.37, 0.23, 0.25 and 0.25mg/liter, and the organic matter 0.64, 0.52, 1.67 and 1.67%, respectively. The results revealed that nutrients play an important role in the density of Babylon in this region. With the increase of nutrients, the density of Babylon increases with a sharp peak and reached the maximum in October and November, and after that, with the decrease of food, the density decreases. Based on multiple linear regression analysis, the nitrite was highly related to the amount of catch per unit effort of the Babylon Sea snail.