01795naa a2200193 a 450000100080000000500110000800800410001910000180006024501040007826000090018252010640019165300110125565300250126665300150129165300130130670000150131970000160133477302510135010361402005-05-25       2000    bl uuuu     u00u1 u    #d1 aOSTRENSKY, A.  aEfeitos da salinidade na toxicidade da amonia para juvenis de Litopenaeus schmitti burkenroad 1936.  c2000  aL. schmitti juveniles (4.45   1.8 g) were tested, in acute semi static bioassay system, for determination of ammonia toxicity, in three salinities, 28, 22 and 15 ppt. Ammonia LC50 (lethal average concentrations) calculated in 24, 48, 72 e 96 h were, respectively, 74.61, 55.08, 36.39 and 35.74 mg/l de TA-N (total ammonia nitrogen), in 28 ppt salinity; 101.57, 79.32, 49.36 and 42.76 mg/l TA-N, in 22 ppt salinity and 105.92, 70.24, 45.86 and 41.35 mg/l AT-N in 15 ppt salinity. NH3-N (gaseous ammonia nitrogen), that is the chemical toxic form of ammonia for fishes and shrimps, LC50 were 4.19, 3.09, 2.04 and 2,01 mg/l NH3-N, in 28 ppt salinity in 24, 48,72 and 96 h, respectively; 5.40, 4.22, 2.63 and 2.27 mg/l NH3-N in 22 ppt salinity and 5.48, 3.63, 2.37 and 2.14 mg/l NH3-N, in 15 ppt salinity. There were not significant differences (P&gt0,05) in ammonia toxicity in relation to salinity in terms of total ammonia or in relation to gaseous ammonia. The safe levels of ammonia estimated to L. schmitti juveniles were 3.57 mg/l TA-N and 0,20 mg/l NH3-N.  aAmonia  aLitopenaeus schmitti  aSalinidade  aToxidade1 aBELZ, C.E.1 aPESTANA, D.  tIn: SIMPOSIO BRASILEIRO DE AQUICULTURA, 11. ENCONTRO SULBRASILEIRO DE AQUICULTURA, 4. ENCONTRO CATARINENSE DE AQUICULTURA, 5. FESTIVAL NACIONAL DA OSTRA E DA CULTURA ACORIANA, 2, 2000, Florianopolis,SC. Anais... Florianopolis: BMLP, 2000. CD-ROM.