Abstrait

Behavioral Responses of Rainbow Trout (Oncorhynchus mykiss) in the Face of Some Environmental Factors (Temperature and Dissolved Ammonia)

Hassan R*, Yalsuyi AM and Vajargah MF

The aim of this study was assessed behavioral responses of rainbow trout (Oncorhynchus mykiss) exposed to some of the environmental factors (temperature and dissolved ammonia). For this purpose, 16 fish in a group control, treating ammonia (treatment 1) and temperature (treatment 2) with four replications was placed in tanks cylindrical volume of 5 l (height 10 cm, diameter section 29 cm) that each tank has a water inlet and outlet, respectively. For all treatments tested to two periods of time (Went and Back) 42 min and a 10-min period (Fixed) were divided. Pattern of fish swimming movements simultaneously from the digital camera (Canon, SX230 Hs, 5.0-70 mm) was recorded. Swimming pattern includes six characteristic average swimming speed, total distance traveled, acceleration level (leap), percentage movements, mean shift displacement and the average distance from the center. Went step includes increasing temperature values of 17°C to 32°C for temperature treatment and ammonia increasing from 0.05 mg/L to 10 mg/L for treatment of ammonia. In contrast, the back step includes reducing values listed to initial amount was. Between swimming patterns of treatment compared with control there was a significant difference (p<0.05). Between swimming patterns of treatment there was significant difference in comparison with each other (p˂0.05). The results of this study suggest that behavioral responses that can be used as early signs of environmental changes.