Poster
INTRODUCTION
Cryptocaryon irritans (Brown, 1951), is a parasitic holotrichous ciliate of marine fishes recognized as etiological agent of the "white spot disease".
During our initial experiences the following treatments have been undertaken: copper sulphate preceded by formalin dip; hypersalinity with quinine and chloroquine (Spotte, 1992; Huff & Burns, 1981) and hyposalinity. Considering the initial speculative promising results obtained, we then concentrated on bath treatment with chloroquine.
MATERIALS AND METHODS
Several chloroquine diphosphate salt (SIGMA Chemical Co.) treatments were carried out on individuals of more than 60 fish species of different ages, sexes, medical history and geographical origin, divided into three categories (carriers, infested, heavily infested) based on visual observations.
The protocol consisted of:
Two days of chloroquine bath at 15 mg/l (concentration to be checked with spectrophotometric method and adjusted on the second day); after initial observation the dose was adjusted by increasing the chloroquine to 20 ppm. The drug was dissolved in untreated natural sea water in dark curatorial tanks without substrate, external filtration with silica or carbonate sand and/or trickle filter.
Elimination of the darkening condition and 30% water change on the third day.
Monitor water parameters (ph, NO2, total ammonia, salinity).
Sequence repeated for four weeks with change of tank after the second week.
Our "experimental" animals were in reality future exhibit animals which couldn't be sacrificed; therefore the effectiveness of the treatment has been analysed on the base of survival rates, disappearance and negative recrudescence of the disease, random autopsies and smears. Husbandry considerations were also made in order to evaluate the practicality and possible side effects of this protocol in an aquarium set-up.
We are now investigating the possibility of an oral administration as proposed for Amyloodinium ocellatum. The initial trials are already providing us with rewarding results (i.e., complete recovery of a heavily infested Arothron meleagris treated by mouth at a dose of 50mg/kg once a week for four weeks with no side effects).