Transportation of live carp fry in sealed polythene bags

Abstract

The transportation of live fish fry in sealed polythene bags with water and oxygen is a common practice, particularly in Southeast Asia. The effect of using unconditioned fish versus conditioned fish and pond water versus bore-hole water on survival during transportation was studied. The fish used were silver carp ( Hypophthalmichthys molitrix) fry of 0.25 g average body weight, that had been reared in fertilised earth ponds. There was a 6% mortality when fish were transferred from ponds to clean water for conditioning. Subsequent transportation in bore-hole water for a 3-h period resulted in 1.75% mortality. Mortality among unconditioned fish transported in bore-hole water for the same period was 6.45%. Transportation of unconditioned fish in pond water resulted in 15% mortality. The trials demonstrated that prior conditioning fish and the type of water used for packing are important in determining survivial. Moreover, the effects of conditioning may be to remove the weaker fish rather than raise the tolerance of all the fish to transportation. Observations are noted on other problems associated with packing and transporting fish fry in oxygenated polythene bags and on the difficulties of interpreting the effects of water quality on fish survival during transportation.