Journal name |
ABBASSA INTERNATIONAL JOURNAL FOR AQUACULTURE |
Publication year |
2009 |
Auther |
Abd El-Galil, M. A. A., ESSA, M. A. A. and KORNI, F. M. M. |
The recent trials for lernaeosis control were directed to the using of
natural substances which are more safe and effective than
organophosphate pesticides. Both crude colophony and its steamed
oil fraction were tested for lernaeosis control in C. carpio fingerlings.
The median lethal concentrations (LC50) of crude colophony (crude
resin) and its steamed oil fraction were tested. It was 46.7ppm for
the crude colophony while up to 100 ppm of steamed oil caused no
deaths among C. carpio fingerlings. Direct and indirect bath exposure
to 5 ppm of steamed oil fraction for 24 hrs, completely eliminated the
lernaea from the infected C. carpio fingerlings post 96 hrs from bath
exposure. On the other hand, the direct bath exposure to 5 ppm of
crude colophony for 24hrs completely eliminated the lernaea from the
infected fish post 120hrs from bath treatment.