INFLUENCE OF STOCKING DENSITY ON SOME WATER QUALITY PARAMETERS AND GROWTH TRAITS IN ANGEL FISH (Pterophyllum skalare)

F. Çağiltay, A. Atanasoff, G. Nikolov

Abstract
    The trial was conducted in aquaria tanks with Angel fish (Pterophyllum skalare) for period of 60 days, to examine the effect of three stocking density on hydro chemical parameters and growth performances. The fish were stocked in three densities 40 (SD1), 80 (SD2) and 100 fish (SD3) per tank in tree replication. They were fed with a food containing 45% protein and food ratio of 3% of its body weight per day. Water quality parameters (T, pH, DО, NO3 and BOD) were recorded on a daily basis. Stock densities had a significant impact on dissolved oxygen (DO), biological oxygen demand (BOD). Changes in pH and nitrates concentrations were insignificant (P>0.05). During the study period, measured values of the hydro chemical parameters were within the effluent limits for ornamental fish. Finally, the body weight was insignificantly affected by water quality and stocking density.

Key words: Angel fish, Pterophyllum skalare, ornamental fish, stocking density, growth parameters, water parameters