Inhaltszusammenfassung

We studied the physiological and behavioral responses of the Ponto-Caspian amphipod Dikerogammarus villosus during exposure to four total ammonia concentrations (NH3 + NH4+; Tot(Amm)): 0.003 (control), 0.06, 1.6, and 7.0 mmol L-1 (0.042, 0.84, 22.4, and 98.0 mg L-1) for a period of up to 12 h at 21 degrees C During the transition period from the control to treatment concentration as well as during the first hour of exposure to 0.06 and 1.6 mmol L-1, gammarids increased their locomotor activit...We studied the physiological and behavioral responses of the Ponto-Caspian amphipod Dikerogammarus villosus during exposure to four total ammonia concentrations (NH3 + NH4+; Tot(Amm)): 0.003 (control), 0.06, 1.6, and 7.0 mmol L-1 (0.042, 0.84, 22.4, and 98.0 mg L-1) for a period of up to 12 h at 21 degrees C During the transition period from the control to treatment concentration as well as during the first hour of exposure to 0.06 and 1.6 mmol L-1, gammarids increased their locomotor activity, which was manifested in significantly higher routine metabolic rates compared to control conditions. At control conditions, the resting metabolic rate amounted to 0.98 ± 0.26 mW g(-1) and significantly increased by 19 and 37% at 0.06 and 1.6 mmol L-1, respectively. The highest examined [Tot(Amm)] caused a rapid and significant increase in resting metabolic rate by 37% within the first 4 h of exposure before gammarids died. The exposure to elevated [Tot(Amm)] also resulted in a significant decreased RNA:DNA ratio and significantly higher glycogen concentrations compared to the control. We conclude that even a short exposure to Tot(Amm) of 0.06 mmol L-1, which may occur in natural habitats, disturbs the physiology and behavior of D. villosus and leads to increased metabolic costs of the maintenance and reduced protein synthesis. (C) 2015 Elsevier Inc All rights reserved. » weiterlesen» einklappen

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