title: Dynamics of some limnological characteristics in pacu (Piaractus mesopotamicus) culture tanks as function of handling.
abstract: In order to study the water quality in fish tanks, a 166-day (January to July 1992) experiment was realized using the indigenous species "p acu" (Piaractus mesopotamicus). Two different protein levels were tested in the diet (16% and 34% crude protein) and three stocking densities (0.25, 0.50 and 0.77 fish/m2). From the results, it was observed that the interactions between stocking density and experiment length affected the characteristics bicarbonate and alkalinity, as well as the interaction between stocking density and protein levels affected concentrations of free and total CO2, conductivity and pH (P < 0.05). The water temperature in tanks changed significantly during the period of study (P < 0.05),decreasing gradually from summer to winter. There was no significant difference in water residence time in the tanks (P < 0.05) during the experiment. The other limnological characteristics were not affected by treatments during study period.
authors.affiliation: UNESP/Centro de Aqüicultura, Rodovia Carlos Tonnani km 5, CEP 14870-000, Jaboticabal, SP, Brazil.
authors.forename: H L
authors.initials: HL
authors.lastname: Sipaúba-Tavares
authors.forename: M A
authors.initials: MA
authors.lastname: de Moraes
authors.forename: F M
authors.initials: FM
authors.lastname: Braga
mesh_terms: D000821:Animal Feed; D000818:Animals; D002245:Carbon Dioxide / Q000032:analysis; D060126:Characidae / Q000502:physiology*; D004044:Dietary Proteins / Q000008:administration & dosage / Q000032:analysis; D004553:Electric Conductivity; D005068:Eutrophication / Q000502:physiology; D005243:Feces; D005398:Fisheries / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D009391:Nephelometry and Turbidimetry / Q000379:methods; D009573:Nitrites / Q000032:analysis; D010100:Oxygen / Q000032:analysis; D011156:Population Density; D013696:Temperature; D014872:Water Movements; D014873:Water Pollutants / Q000032:analysis*; D060753:Water Quality
chemical_list: D004044:Dietary Proteins; D009573:Nitrites; D014873:Water Pollutants; D002245:Carbon Dioxide; D010100:Oxygen