Dietary potassium requirement of juvenile grass shrimp Penaeus monodon
Fisheries Science, 67(4): 592-595
Abstract:
A feeding trial was conducted to estimate the minimal
dietary potassium (K) requirement for juvenile grass shrimp Penaeus
monodon. Purified diets with seven levels (0, 0.3, 0.6, 0.9, 1.2, 1.5,
2.0 g/100 g) of supplemental potassium were fed to P. monodon (mean
initial weight 0.75 ± 0.01 g) for 8 weeks. Each diet was fed to three
replicate groups of shrimp. The rearing water contained 360 mg/L potassium.
Weight gain and protein efficiency ratio (PER) of shrimp improved as dietary
potassium supplementation level increased up to 1.5 g K/100 g diet and
thereafter declined significantly (P < 0.05). Feed efficiency (FE)
of shrimp also showed a similar trend. However, whole body K concentration
of the shrimp kept an increasing trend up to 2.0 g K/100 g diet. Analysis of
the weight gain (percent) and PER of the shrimp by polynomial regression
indicate that the minimal dietary potassium requirement in growing P.
monodon is approximately 1.2 g/100 g.
(Department of Food Science, National Taiwan Ocean
University, Keelung, Taiwan 202, Tel: 886-2-2462-2192 ext 5106. Fax: 886-2-2462-1684. Email: syshiau@mail.ntou.edu.tw)