Effects of transport media and duration on the mortality and physiological responses in silver carp Hypophthalmichthys molitrix fingerlings

Abstract

This study evaluated the effects of three transport media i.e., well water
(WW), pond water (PW) and mixture of the two (WPW; 1 : 1) and durations (1, 3,
6 and 9 hrs) on the mortality and physiological responses in silver carp,
Hypophthalmichthys molitrix fingerlings in a transport simulation at 400 g/l
loading density. While the total mortality was lower than 9% until 6 hrs of
transport, it was very high (49 - 60%) at 9 hrs across all three treatment media.
The highest level of cortisol was measured in the fingerlings simulated using
WPW while the lowest level was detected in the fingerlings sampled form WW.
The level of cortisol observed in the fingerlings simulated using PW was not
different from other two media. Between durations, the levels of cortisol
observed were significantly different. The highest chloride level was measured
in the fingerlings simulated using WW while the lowest level was observed in
the fingerlings sampled from WPW. PW did not result in different chloride level
from those of WW and WPW. Among duration treatments, while 9 hrs resulted
in the lowest level of chloride, the highest level was detected at 1 hr. The results
suggest that WW, PW and WPW can be used as medium in transporting well
conditioned silver carp fingerlings for 6 hrs with little mortality and less stress
effects.