11 research outputs found
Growth of silver catfish ( Rhamdia quelen ) exposed to acidic pH at different humic acid levels
Mesembrinellinae (Diptera: Calliphoridae) to edge effects in the Tinguá Biological Reserve, Rio de Janeiro, Brazil
Method of capture and population structure of Aegla georginae Santos and Jara, 2013 (Decapoda: Anomura: Aeglidae) in a tributary of the Ibicuí River in southern Brazil
Dietary protein levels in piaractus brachypomus submitted to extremely acidic or alkaline ph
The objective this study was to evaluate the effects
of dietary protein levels in pirapitinga, Piaractus brachypomus,
submited to extremely acidic or alkaline pH. Juveniles were fed for 20
days with three diets with different crude protein (CP) levels (25.3, 32.4
and 40.0%) and then separated in fi ve groups (n=10, three replicates
each) which were kept in 60 L aquaria and exposed to pH 3.0, 3.5,
7.0, 10, or 10.5. Fish were removed from aquaria when they showed
loss of swimming balance, and then blood was collected and plasma
separated for measurement of Na+, Cl- and K+ levels. The increase
of dietary protein levels (up to 40.0% CP) provided some protection
for pirapitinga at pH 3.5 or 10.0 because the time to lose equilibrium
increased after acute exposure, but was not effective for compensating
ion loss at very acidic (Na+ and Cl-) and alkaline (Cl-) pH.O objetivo deste estudo foi avaliar o efeito dos níveis
de proteína na dieta de pirapitinga, Piaractus brachypomus,
submetidas a pH extremamente ácido ou alcalino. Os juvenis foram
alimentados durante 20 dias com três dietas com diferentes níveis
de proteína bruta (PB) (25,3; 32,4 e 40,0%) e, em seguida, foram
separados em cinco grupos (n=10, três repetições cada), os quais
foram colocados em aquários de 60L e expostos aos pH 3,0; 3,5;
7,0; 10 ou 10,5. Os peixes foram removidos dos aquários quando
apresentaram perda de equilíbrio natatório, o sangue foi então
coletado e o plasma separado para determinação dos níveis de
Na+, Cl- e K+. O aumento dos níveis de proteína na dieta (até 40%
PB) forneceu alguma proteção para pirapitingas em pH 3,5 ou
10,0, porque o tempo para perder o equilíbrio natatório aumentou
após a exposição aguda, mas não foi efetivo para compensar a
perda de íons em pH muito ácido (Na+ e Cl-) ou alcalino (Cl-)
Larvas de linhagens de tilápia do Nilo submetidas à frequências alimentares sob baixa temperatura
Probiotic actions of Bacillus cereus var. toyoi and Saccharomyces boulardii in silver catfish (Rhamdia quelen) larvae culture
The objective of this study was to evaluate the use of Bacillus cereus var. toyoi and Saccharomyces boulardii as probiotics to improve Rhamdia quelen culture. Six hundred larvaes (0.16±0.07 g) were divided in three replicate tanks (25-L recirculation, 20 ºC, photoperiod of 12 h light/12 h darkness) per treatment and were randomly assigned to the following treatments: Bacillus cereus var. toyoi; Saccharomyces boulardii; B. toyoi and S. boulardii; and control (without probiotic addition) for a period of 30 days. The fish were fed five times daily (56% crude protein - Supra alevino inicial®) and the probiotics were applied in water once a day. The doses of probiotics were <img src="/img/revistas/rbz/v41n3/aproximadamente.jpg">5 × 10(8) and <img src="/img/revistas/rbz/v41n3/aproximadamente.jpg">2 × 10(9) CFU (colony forming unit)/mL for B. cereus var. toyoi and S. boulardii, respectively. Both probiotics have an inhibitory effect in vitro against Vibrio carchariae and are able to grow in media prepared with fishery water; however, no effect was observed on growth parameters when they were administered to Rhamdia quelen larvae