02123naa a2200289 a 450000100080000000500110000800800410001902200140006002400430007410000220011724501700013926000090030952012240031865000160154265000190155865000180157765000090159565000140160465000100161865000130162865300310164170000240167270000300169670000220172670000190174877300660176721492852023-04-16       2023    bl uuuu     u00u1 u    #d  a0140-77757 ahttps://doi.org/10.1111/jfd.137252DOI1 aARAÚJO, P. A. de  aEfficacy of chlorine, sodium chloride and trichlorfon baths against monogenean Dawestrema cycloancistrium parasite of pirarucu Arapaima gigas.h[electronic resource]  c2023  aThis study investigated the efficacy of sodium chloride (SC) and trichlorfon (T) against Dawestrema cycloancistrium and its physiological effects on Arapaima gigas. The efficacy of chlorine (C) as a prophylactic disinfectant was also evaluated. In vitro test with 15 treatments were: SC 4, 8, 10, 12, 14 g/L, T0.1, 0.4, 0.8, 1.6, 3.2 mg/L, and C500, 1000, 3000, 6000 mg/L. Scanning electron microscopy was performed to evaluate parasite damage. The in vivo test was as follows: control, 4 h short baths, once a day, for four consecutive days (SC12 g/L, T5 mg/L); 24 h long baths, for 2 days in 24 h intervals (SC10 g/L, T5 mg/L). In vitro exposure to SC12 and 14 g/L caused 100% mortality of monogeneans at 45 and 60 min, while at T3.2 and 1.6 mg/L 100% of monogeneans died at 30 and 60 min, respectively. In vitro exposure to C resulted in complete mortality after 2?5 min exposure. The SC and T LD50?96 h were 9.9 g/L and 9.73 mg/L, respectively. All in vivo treatments presented efficacy above or close to 90%, with low survival in the long baths. C, starting at 500 mg/L for 5 min, can be used as a disinfectant. Short baths with SC12 g/L and T5 mg/L are recommended for D. cycloancistrium infestations in Arapaima.  aAquaculture  aArapaima gigas  aEctoparasites  aFish  aParasites  aPeixe  aPirarucu  aDawestrema cycloancistrium1 aMACIEL-HONDA, P. O.1 aCOSTA-FERNANDES, T. de O.1 aSANTOS, G. G. dos1 aMARTINS, M. L.  tJournal of Fish Diseasesgv. 46, n. 2, p. 113-126, Feb. 2023.