Abstract

In the mollusks bivalves, although the capacity of excretion of ammonia is high from a 60 to the 90%, they have been proposed like biofliters in systems of cultivation. The bivalves were collected in the beach Nazareth of the Zulia state. The experimental design consisted of three densities of bivalves: low density (2 ind/L), average (4 ind/L) and highly (6 ind/L), with a control without organism, placed in plastic trays of 10 L of water, originating from the Limon River estuarine System, with salinity of 1 UPS and with levels of ammonia 0 mg/L. A trial by species was carried out, with three replicas respectively. They were measured the composed nitrogenous (Ammonia, nitrite and nitrate) to the following hours: 0, 6, 12, 24, 36, 48, 60, 72, 84 and 96. The results show that to the extent that enlarges the density of bivalves is increased the ammonia and at the same time its oxidation to Nitrite and nitrate. According to the variations of the concentrations of Ammonia for P. solida and G. demissa in the low density was: 0.25 mg/L and <0,25 mg/L, the average density 0.5 mg/L and 0.25 mg/L, and the high density 1 mg/L and 0.50 mg/L respectively. Comparing the two species studied, the mussel G. demissa obtained a smaller excretion of ammonia, and this indicates that the low density of 2 ind/L could be the most recommendable one for the use as biofliters in the aquaculture.

PDF Preview