Pengaruh penurunan salinitas air terhadap laju pertumbuhan dan kelangsungan hidup udang windu (Penaeus monodon Fabricius)=The Effect of Decreasing in Water Salinity on the Growth and Survival Rate of the Tiger Prawn (Pen

ABSTRACT The main purpose of this study was to determine the effect of decreasing in water salinity on the growth and survival rate of the tiger prawn (Penaeus monodon Fabricius). The growth and survival rate were very much influenced by the quality of environtmental factors and the prawn\u27s ability to adapt on water salinity changes. The experiment was conducted by using glass aquaria, complete with aeration. The water salinity was decreased every three weeks, at a 5 ppt concentration interval. The water salinity in the four control aquaria remained constant during the experiment. Observation on the rale of weight growth, length of prawn and water quality were conducted each week Randomized Completed Design of 5 treatment and 4 replication were used in this experiment. The results of the experiment shown that the decreasing in water salinity affected the absolute weight growth and daily weight growth rate and significantly differed between treatments. But there was no significant difference in the total growth rale and carapac length_ The growth rate the standard length was significantly different between treatments. The effect of decreasing in water salinity to water quality showed that unionized ammonium concentration (NH3), ion nitrit (NO2), free carbon dioxide (CO2), dissolved oxygen and water temperature were not significantly different between all the treatments. Key words: salinity - Penaeus monadon Fabricius - water sanilit