effect of iodine
disinfection on the bacterial flora and hatching rate of grouper,
epinephelus coioides eggs at the cleavage and eyed stages
E.A. Tendencia-2001
Bull. Eur. Ass. Fish Pathol., 21(4): 160-163
Abstract:
In this study, the effect of iodine disinfection on
the bacterial flora and hatching rate of grouper egg at two different stages
of development were investigated. The eggs (at cleavage and eyed stages)
were soaked for 10 min in sterile seawater (control) and at different free
iodine concentrations – 2.5, 5, 10 and 20 ppm. Total bacterial and
presumptive Vibrio count, as well as the hatching rate of the treated eggs
were determined. Results showed that Vibrios are eliminated by iodine
disinfection (2.5-20 ppm) but not by rinsing with sterile seawater. The
total bacterial load and hatching rate of eggs decreased as the iodine
concentration increased. Iodine concentrations of 15 and 20 ppm were
effective in significantly reducing the total bacterial load of grouper egg
at both the cleavage and eyed stages. However, at these concentrations the
hatching rates were also significantly lower. Results also showed that
grouper, Epinephelus coioides, eggs tolerate stress better at the eyed stage
than at the cleavage stage.
(Southeast Asian Fisheries Development Center,
Tigbauan, Iloilo 5021, Philippines)