Single or paired increase of total alkalinity and hardness of water for cultivation of Nile tilapia juveniles, Oreochromis niloticus

Abstract

ABSTRACT. The present work aimed at evaluating the effects of single or paired increase of water's total alkalinity (TA) and total hardness (TH) on the performance of Nile tilapia juveniles' growth and culture water quality. Twenty five 25-L outdoor polyethylene aquaria were used to hold experimental fish (0.82 ± 0.06 g; 10 fish per aquarium) for 6 weeks. There were two conditions of TA (low or high) and of TH (moderate or high) in the culture water, obtained by the application of different salts (CaCO 3 , Na 2 CO 3 and CaSO 4 ) upon a previously acidified water, all at the same rate. Water quality and growth performance variables were observed in each replicate. The acidification of the supply water with HCl has resulted in significantly lower final body weight (p < 0.05). Except for the Na 2 CO 3 , growth performance of tilapia has improved significantly after CaCO 3 liming or CaSO 4 application (p < 0.05) and no significant difference was detected between these last two fish groups (p > 0.05). It was concluded that beyond a minimum level of TA (≥ 20 mg L CaCO 3 ), it is also important that fish culture waters have a TH/TA ratio higher than 1.Keywords: calcium carbonate, calcium sulfate, fish culture, liming, sodium carbonate.Aumento isolado ou combinado da alcalinidade e dureza da água de cultivo de juvenis de tilápia do Nilo, Oreochromis niloticus RESUMO. O presente trabalho teve como objetivo avaliar os efeitos do aumento isolado ou combinado da alcalinidade total (AT) e da dureza total (DT) da água no desempenho produtivo de juvenis de tilápia do Nilo e na qualidade da água de cultivo. Vinte e cinco aquários de polietileno de 25 litros foram utilizados, cada um contendo dez juvenis de tilápia (0,82 ± 0,06 g), que foram cultivados durante o período de seis semanas. Havia duas condições de AT (baixa ou alta) e duas de DT (moderada ou alta) que foram obtidas a partir da aplicação de diferentes sais (CaCO 3 , Na 2 CO 3 and CaSO 4 ) em água previamente acidificada com HCl, todos na mesma taxa. Após seis semanas, os peixes mantidos em água acidificada apresentaram peso corporal significativamente menor que o observado no grupo controle (p < 0,05). Exceto pelo Na 2 CO 3 , o desempenho produtivo da tilápia melhorou significativamente após a aplicação de CaCO 3 ou CaSO 4 na água (p < 0,05), não havendo diferença significativa entre esses dois últimos grupos (p > 0,05). Concluiuse que além de níveis mínimos de AT (≥ 20 mg L CaCO 3 ), é também importante que a água de cultivo de peixes apresente relação DT/AT maior que um.Palavras-chave: carbonato de cálcio, sulfato de cálcio, piscicultura, calagem, carbonato de sódio.

Growth, water quality and oxidative stress of Nile tilapiaOreochromis niloticus(L.) in biofloc technology system at different pH

“…The Nile tilapia is tolerant to a wide range of pH (El‐Sherif & El‐Feky, ; Lim & Webster, ), but our results demonstrate growth reduction for pH 8.3. Cavalcante, Silva, Pinheiro, Akao, and Sá () demonstrated improvement in Nile tilapia growth when hardness:alkalinity ratio was maintained equal or superior to 1.0, which in the present study was achieved at pH 7.5 and 6.5.…”

“…Each value represents mean ± SD; superscript letters represent statistical difference (Tukey, p < 0.05; n = 6). Antioxidant capacity against peroxyl radicals (ACAP, a) and lipid peroxidation (LPO, b) in gills and liver of Nile tilapia Oreochromis niloticus raised at pH 8.3, 7.5 and 6.5 (mean ± SD; ANOVA p < 0.05; n = 6)The Nile tilapia is tolerant to a wide range of pH(El-Sherif & El-Feky, 2009;Lim & Webster, 2006), but our results demonstrate growth reduction for pH 8.3 Cavalcante, Silva, Pinheiro, Akao, and Sá (2012). demonstrated improvement in Nile tilapia growth when hardness:alkalinity ratio was maintained equal or superior to 1.0, which in the present study was achieved at pH 7.5 and 6.5. stability of parameters such as temperature, oxygen, pH and low concentration of TAN and NO 2 − .…”

Freshwater parameters in the state of Rio Grande do Sul, southern Brazil, and their influence on fish distribution and aquaculture

“…However, growth of male sex reversed juvenile O. niloticus was higher at 146 mg L -1 CaCO 3 (increased with CaCO 3 ) than at 82 mg L -1 CaCO 3 (Cavalcante et al, 2009), indicating that water hardness must be increased to raise this species in this state. As observed with R. quelen, the increase in water hardness also improved survival and physiologic condition of exotic species, such as O. mykiss (McDonald et al, 1980), C. carpio (Chezhian et al, 2011) and O. niloticus (Cavalcante et al, 2012), exposed to acidic water.…”

“…However, minimum values indicated that water from a few cities must be alkalinized before using in aquaculture to avoid mortality (Table 1) and/or reduced growth of the native species silver catfish (Rhamdia quelen) (Copatti et al, 2005;2011;Baldisserotto, 2011) and Argentinian silverside (Odontesthes bonariensis) (Gómez et al, 2007), or exotic species common carp (Cyprinus carpio) (Heydarnejad, 2012) and Nile tilapia (Oreochromis niloticus) (El-Sherif & El-Feky, 2009;Cavalcante et al, 2012). Maximum pH values (9.3) were outside the safe range for aquaculture only in the City of Rio Grande (Table 1), but since these are mean monthly values and not absolute maximum values it is likely that alkaline pH values may eventually occur in some cities from the western and eastern regions of this state.…”

“…Larvae of P. lineatus and O. niloticus had better growth at an alkalinity of 30 mg CaCO 3 mg L -1 compared to 15-20 and 55-60 mg CaCO 3 mg L -1 (Rojas et al, 2001;Rojas & Rocha, 2004;Paes et al, 2011), but these studies used hydrated lime (CaCO 3 .2H 2 O) to increase alkalinity, which also changed water hardness. The increase in alkalinity from 22 to 80 mg CaCO 3 mg L -1 with the addition of Na 2 CO 3 (without changing water hardness) did not affect any growth parameter of male sex reversed juveniles of O. niloticus (Cavalcante et al, 2010) nor improved growth of those raised in acidic water (Cavalcante et al, 2012), demonstrating that for this species water hardness is more important. Therefore, apparently, alkalinity is not a parameter that will affect the aquaculture of native or exotic fishes in Rio Grande do Sul.…”