Effect of chronic ammonia exposure on growth of European seabass (Dicentrarchus labrax) juveniles

Abstract

Chronic effects of ammonia were studied in juvenile seabass, Dicentrarchus labrax (mean WEIGHT=11 g), exposed for 63 days to eight stable ammonia concentrations, ranging from 0.24 to 0.90 mg l−1 unionised ammonia nitrogen (UIA-N), respectively, from 6.1 to 22.3 mg l−1 total ammonia nitrogen (TA-N). Temperature (21.8 °C), pH (8.0), salinity (37.0 ppt), and oxygen concentration (over 80% saturation at the outlet) were maintained constant. Fish were fed using a self-feeder device, and they were starved during the last 8 days. Mortality of 28.9 and 42.6% occurred within the first 8 days at the two highest UIA-N concentrations, respectively, 0.90 and 0.88 mg l−1. From days 0 to 55, a 1.8fold increase in weight gain was observed under the 0.90-mg l−1 UIA-N condition, compared to a 3.4fold increase in the control. Weight gains were negatively correlated to ambient ammonia concentrations. Weight loss, or a transient period of growth stagnation, was observed from the onset of ammonia exposure to day 13 in seabass exposed to concentrations above 0.43 mg l−1 UIA-N. After day 13, weight gains were observed in all groups, indicating that the fish were able to adapt to increased ambient ammonia concentrations over time. By the end of the experiment, plasma ammonia levels were positively related to ambient ammonia concentrations, and oxygen consumption recorded in fasting fish was significantly dependent on ammonia concentrations. In seabass juveniles, the 0.26mg l−1 UIA-N concentration, under an average pH of 8.0, can be considered as a safe long-term limit conditions in seawater.

Tolerance to temperature, pH, ammonia and nitrite in cardinal tetra, Paracheirodon axelrodi, an amazonian ornamental fish

“…The results obtained in this study are within the toxicity range suggested by Abdalla & MacNabb (1998), in which the lethal concentration of unionized ammonia for fish varies between 0.32 e 3.1 mg/L. Several authors have described the lethal levels (LC 50 ) of total and unionized ammonia for different fish species (Lemarié et al, 2004), such as Ictalurus puntactus, 45 mg/L NH 3 + NH 4 + and 1.6 mg/L NH 3 (Colt & Tchobanoglous, 1976), Oncorhynchus mykiss, 22 mg/L NH 3 + NH 4 + and 0.3-0.6 mg/L NH 3 (Haywood, 1983), Odontesthes argentinensis, 0.76-0.96 mg/L NH 3 (Ostrensky & Brugger,1992;Sampaio & Minillo, 2000), and Cichlasoma facetum, 2.95 mg/L NH 3 (Piedras et al, 2006). The data obtained indicate that the cardinal tetra may be considered as to be tolerant to ammonia, which certainly facilitates its survival, especially during transport from Barcelos to Manaus, when the total ammonia can reach high concentrations (< 12 mg/L) (Waichman et al, 2001).…”

Lethal concentration (CL50) of un-ionized ammonia for pejerrey larvae in acute exposure

“…According to ElShafai et al (2004), 0.26 mg L -1 NH 3 -N do not kill but negatively affect the proteic efficiency of tilapia Oreochromis niloticus juveniles. Similar results are registered by Lamarié et al (2004), who consider 0.26 mg L -1 NH 3 -N the maximum acceptable concentration to maintain weight gain performance of European seabass Dicentrarchus labrax juveniles. Bergmann (1994) emphasizes that NH 3 -N toxicity results from its interaction with other water quality parameters, such as pH, ionized ammonia and microbial activity in the sediment, and shows diurnal variation according to intensity of photosynthesis and respiration processes occurring in the environment.…”

“…Increasing ammonia concentration in blood and other tissues (e.g. brain, liver, and muscle) negatively affects cerebral synaptic connections (Lamarié et al, 2004).…”

Tolerance of piava juveniles to different ammonia concentrations

“…Seabass, seabream, and turbot juveniles that were exposed to 6.43, 4.87, and 5.70 mg L -1 NH 3 , respectively, for 96 h also exhibited increased plasma concentrations of NH 3 (RUYET et al, 1995). Seabass that were exposed to different NH 3 concentrations (0.71, 0.88 and 0.90 mg L -1 ) for 63 days showed a positive relationship between plasma ammonia and NH 3 concentrations (LEMARIÉ et al, 2004). The high NH 3 concentrations may have also affected ammonia levels of other tissues (Fig.…”