The resistance to ammonia
stress of Penaeus monodon Fabricius juvenile fed diets supplemented
with astaxanthin
C.-H. Pan, Y.-H. Chien, B. Hunter-2003
Journal of Experimental Marine Biology and Ecology, 297(1): 107-118
Abstract:
This study was aimed at determining if the increase
of body astaxanthin content through dietary supplementation in tiger prawn Penaeus
monodon juvenile could enhance its antioxidant defense capability and
resistance to ammonia stress. Haemolymph total antioxidant status (TAS) and
superoxide dismutase (SOD) were chosen as parameters of shrimp antioxidant
capacity. Resistance to chemical stress was evaluated by shrimp survival
rate, and haemolymph aspartate aminotransferase (AST) and alanine
aminotransferase (ALT). P. monodon 5-day postlarvae were fed diets
supplemented with 0 and 71.5 mg kg-1 astaxanthin for 8 weeks.
Shrimps were then subjected to 72-h exposure of ammonia at 0.02, 0.2, 2 and
20 mg l-1. The survival rates of the astaxanthin-fed (AX) shrimp
were higher than those of the control shrimp under all levels of ammonia
except 20 mg l-1, showing that the shrimp's resistance to ammonia
stress had been improved by dietary astaxanthin. AX shrimp had higher TAS
than control shrimp at ammonia levels higher than 0.02 mg l-1 and
lower SOD at all ammonia levels suggested that antioxidation capability had
been greatly enhanced. AST in AX shrimp was lower than that in control
shrimp under all levels of ammonia stress. ALT in AX shrimp was either lower
than or equal to that in control shrimp under various levels of ammonia.
Both AST and ALT reflected that shrimp hepatopancreatic function had been
improved by dietary astaxanthin. Astaxanthin can become essential for P.
monodon when the animal is under ammonia stress.
(Department of Aquaculture, National Kaohsiung
Institute of Marine Science and Technology, Kaohsiung 811, Taiwan, ROC,
e-mail of Y.-H. Chien: yhchien@mail.ntou.edu.tw)