Acclimation and culture of Penaeus monodon at low salinities in closed water system
- Bangkok : Asian Institute of Technology, 1995
- 70 leaves + 1 online resource
- Thesis ; no. AE-95-33 .
- Asian Institute of Technology. Thesis ; no. AE-95-33 .
A Thesis Submitted in Partial Fulfilment of the Requirement for the Degree of Master of Science, School of Environment, Resources, and Development
Thesis (M.Sc.) - Asian Institute of Technology, 1995
Three short experiments were conducted to determine the survival of Penaeus monodon postlarvae (PL20 ) in abrupt change to salinities from seawater ( 35 ppt) to freshwater and through 5 ppt and 1 ppt stepwise dilution over a period of 4-7 hours. The abrupt change of salinity resulted in 100 % mortality, while 100 3 survival was recorded at 1 ppt when the animals were allowed to stay relatively longer period of acclimation with minimum ranges of salinity changes. Following the survival test, shrimps were reared at different 2 salinities (0 , 1 , 2, 3, 4 and 20 ppt) for 75 days at a density of 40 shrimps/m in closed system. Results obtained from the rearing trials showed that growth and survival were not significantly different among the treatments. Near est mean weight was obtained from all the test salinities ranging from 6 . 06 ±. 38 g at 20 ppt and 6.62 ± .27 g at 4 ppt. The overall survival was low ( 30-40 %} registering the highest at 0 ppt and the lowest at 3 ppt. The apparent FCR values varied from 2. 5 to 2 . 9 among the treatments. Temperature ( 0 c), dissolved oxygen (mg/l), and pH played no significant difference within the treatments but total NH3 -N (mg/l) and TSS (mg/l) concentrations were significantly higher in treatment 1 ( 20 ppt) than the rest of the treatments