Cause: Piscinoodinium sp. (Synonim: Oodinium sp.)
Bio - Ecology phatogen:
• Represents ekto round-shaped parasites
• parasitic phase is shaped like a pear, diselaputi membrane and appendix as a tool resembling rizoid penempel in fish. The length of this face depends on water temperature, the temperature of 25 degrees Celsius for ± 6 days to reach adulthood.
• a severe infection can kill up to 100% in a few days.
• The organ is the target of infection include skin, fins and gills.
• As an adult, parasite escape from the host, turned into tomont and splitting into gymnospore. Gymnospore is the infective stage that swim like a spiral to find the host, if the
tempo of 15-24 hours did not find the host, the stadia will be dead.
Clinical Symptoms:
• Fish looks nervous, fluffy gill cover, folded fins, and rapid thin. The population of parasites in the skin resulting in golden color, rusty or brownish white (dirty) so often called "velvet disease".
• Fish often make sudden movements, fast and no
balanced "flashing" and will be obvious at the time of the morning
or evening.
. Rubbed his body on hard objects around him, and pale body color.
Diagnosis:
• Visual observation of the parasites on the skin, fins and gills of fish
• Microscopic observation to see the morphology of the parasite through the production segment of the organ preparations skin / mucus, fins and / or gills.
Control:
• Maintain the temperature for always> 29 degrees Celsius
• The transfer of parasite-infected fish populations to parasite-free water 2-3 times at intervals of 2-3 days.
• Treatment and / or eradication of parasites, among other things can be done through the immersion test:
✓ salt water (1 -10 PROMIL, depending on species and size of fish) for several hours, transferred to water that is free of parasites and repeated every 2-3 days.
✓ solution of hydrogen peroxide (H2O2) at a dose of 150 ppm for 30 minutes, transferred to water that is free of parasites and repeated every 2 days.
✓ solution of copper sulphate (CuSO4) at doses of 0.5 to 1.0 ppm for 5-7 days with strong aeration, and water must be replaced every day.
✓ 25-50 ppm formalin solution for 12-24 hours, made repeated every 2 days. Methylene blue at a dose of 2-6 ppm for 3-5 days.
✓ Acriflavin solution at a dose of 0.6 ppm for 24 hours, and repeated every two days.
sumber : Kementerian Kelautan dan Perikanan, Dirjen. Perikanan Budidaya,2010
