نوع مقاله : مقاله پژوهشی
عنوان مقاله English
نویسندگان English
This study was conducted from June to October 2023 at shrimp farming sites in Gomishan, located in Golestan Province, with the aim of investigating the relationship between shrimp growth and biological and abiotic factors in culture ponds. A total of three farms were selected from Line 2, and from each farm, three ponds were used for sampling shrimp, zooplankton, phytoplankton, benthos, and water quality parameters. Zooplankton species identified included: Foraminifera, Copepoda, Naupli Copepod, various free-living nematodes, polychaete larvae, juvenile larvae of Streblospio gynobranchiata, Gammarus, larvae of Ephydra sp., and Rotifera. Benthic organisms identified included: Nereis, Gammaridae, Chironomidae, Cerastoderma, Ecrobia, Theodonus, Dreissena caspia, Ephydra, and Streblospio gynobranchiata. Water quality parameters recorded during the study were as follows: ammonia concentrations ranged from 0.02 to 0.11 mg/L; nitrate levels varied between 0.07 and 0.68 mg/L; pH fluctuated between 8.1 and 8.73; total dissolved solids (TDS) ranged from 18.63 to 29.45 mg/L; water transparency ranged from 41 to 160 cm; salinity values ranged from 18.8 to 31.2 g/L; dissolved oxygen levels varied between 6.2 and 8.66 mg/L; and water temperature ranged from 22.41 to 29.81°C. The highest specific growth rate (SGR) was recorded as 12.67% per day in Farm 4 on the 25th day of cultivation, while the lowest SGR was 3.7±0.02% per day in Farm 7 on the 72nd day of cultivation. Correlation analysis between SGR and physical-chemical parameters indicated a significant positive linear correlation with dissolved oxygen at the 1% significance level (r= 0.886), and a significant negative linear correlation with salinity at the 5% significance level (r= -0.319). Overall, this study demonstrates that water physicochemical conditions, particularly dissolved oxygen and salinity, play a crucial role in shrimp growth performance. Additionally, a decrease in feed conversion ratio (FCR) suggests that shrimp maybe partially fulfilling their nutritional needs through naturally occurring live food in the ponds. However, for improved production and productivity, optimal environmental management and the application of modern aquaculture technologies are essential. Farm managers should pay increased attention to feeding amounts, precise monitoring of feeding methods, and frequency. In the later stages of the culture period, water exchange and salinity reduction can be critical measures for enhancing shrimp performance.
کلیدواژهها English
