Mitigation of lethal effects of Karlodinium veneficum and K. armiger on Sparus aurata: changes in haematocrit and plasma osmolality.
Between January and April 2000, several experiments were performed during a Karlodinium spp. proliferation in Alfacs Bay (Ebro delta, NW Mediterranean) to determine the effects of these dinoflagellates on sea bream Sparus aurata cultivated in the area. Moribund fish showed an increase in plasma osmolality together with a decrease in the haematocrit percentage compared to control fish. The efficacy of copper sulphate, hydrogen peroxide, potassium permanganate and formalin against Karlodinium spp. was also tested. None of these treatments had mitigation effects when applied in the presence of fish; on the contrary, lethal effects appeared at lower Karlodinium spp. densities compared to fish control groups. When a lytic agent, such as copper sulphate, was used as a water pre-treatment, in the absence of fish, Karlodinium spp. toxicity was significantly reduced. Protocols for water pre-treatments were studied as a potential tool for combating Karlodinium spp. in fish farms.
Fernández-Tejedor
Margarita
M
IRTA, PO Box 200, 43540 Sant Caries de la Ràpita, Spain. margarita.fernandez@irta.es
Soubrier-Pedreño
M Angeles
MA
Furones
M Dolores
MD
D000818:Animals; D017756:Aquaculture; D019327:Copper Sulfate / Q000633:toxicity; D004141:Dinoflagellida / Q000187:drug effects* / Q000502:physiology; D004202:Disinfectants / Q000633:toxicity; D005393:Fish Diseases / Q000401:mortality / Q000469:parasitology* / Q000503:physiopathology / Q000517:prevention & control*; D005557:Formaldehyde / Q000633:toxicity; D006400:Hematocrit / Q000662:veterinary*; D006861:Hydrogen Peroxide / Q000633:toxicity; D009994:Osmolar Concentration; D011196:Potassium Permanganate / Q000633:toxicity; D011528:Protozoan Infections / Q000401:mortality / Q000503:physiopathology / Q000517:prevention & control; D011529:Protozoan Infections, Animal; D021541:Sea Bream / Q000469:parasitology*
D004202:Disinfectants; D011196:Potassium Permanganate; D005557:Formaldehyde; D006861:Hydrogen Peroxide; D019327:Copper Sulfate