Areechon, N.
Abstract:
A vitamin C derivative, ascorbyl dipotassium 2-sulfate dihydrate, was applied directly in the sea water used to raise black tiger shrimp (Penaeus monodon Fabricius) from nauplius to postlarval stage at concentrations of 0, 50, 100 and 150 mg/l. The efficacy of the treatment was tested by monitoring the performances of the postlarval against some commonly experienced environmental factors. The LC50 at 24 hours after exposure to ammonia and methyl parathion were 53.5, 59.0, 57.0, and 63.0 ppm and 2.70, 3.40, 3.65, and 3.15 ppb for larvae raised with 0, 50, 100 and 150 ppm of ascorbyl 2- sulfate dihydrate respectively. Sudden change of salinity from 30 ppt to 5 ppt and 0 ppt revealed the benefits of using ascorbyl dipotassium 2-sulfate directly in the rearing water of hatchery. This is especially significant immediately after transfer. This trend was also found in the stress test using varying concentrations of dissolved oxygen. It was concluded that asocrbyl 2-sulfate applied directly in the sea water (used to raised the black tiger shrimp larvae) could act as an anti-stress factor against toxic substance and some unfavourable conditions by enhancing the tolerant level against ammonia and methyl parathion. Furthermore, shrimp raised with ascorbyl dipotassium 2-sulfate in the water survived longer in drastic salinity change and low dissolved oxygen level.
(Department of Aquaculture, Faculty of Fisheries, Kasetsart University, Jatujakr, Bangkok 10900)
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