Emerson Carlos Soares

Cultivo de tambaqui em canais de abastecimento sob diferentes densidades de peixes

Modern fish farming is based upon best-practice breeding technology, environmental quality and productivity benefit. In this experiment we analyzed fish density effects on water quality, and afterwards on breeding efficiency of Tambaqui (Colossoma macropomum). Juveniles with an average weight of 13,6 ± 4,1 g were reared in 40 m long irrigation channels, which were divided in 15 sections of 1 m3 in each case. Three fish densities (60, 90 and 120 individuals per m3) were tested, with five replications. Water quality parameters were as follows: water temperature 28,0-31,7 °C, dissolved oxygen 5,9-7,4 mg L-1, pH 6,8-7,5, ammonium concentration 0,1-0,3 mg L-1, alkalinity 24,0-34,0 mg L-1 (CaCO3), hardness 24,0-37,0 mg L-1 (CaCO3, MgCO3), conductivity 0,07-106 µS cm-1 and total dissolved solids 18,37-53,00 mg L-1. The increase in fish weight was 35,76, 32,95 and 36,25 g for fish density of 60, 90, and 120 individuals per m3, respectively. No difference among fish density was observed. In conclusion, there is the possibility of integrating the fish farming with other cultures, maximizing the use of water resources.

Protease exógena em dietas para juvenis de tucunaré-paca (Cichla sp.)

This experiment analyzed the enzymatic activity of the exogenous protease in the fish digestive tract and, afterwards, it was also evaluated the growth performance of tucunare paca (Cichla sp.) juvenile by the addition of four exogenous protease levels to a control diet with 40% CP. To evaluate the best enzyme inclusion level, four pelleted diets were elaborated with the following exogenous protease levels (0.00, 0.05, 0.10 and 0.15%), in a completely randomized design in a 4 × 4 factorial arrangement. The best results of average weight gain, feed conversion ratio, and weight specific growth rate were showed by the animals fed with diet containing 0.10% of exogenous protease. The exogenous protease enzyme added to the diet affected the body characteristics of tucunare paca juvenile.

Eficiência do aguapé sobre variáveis limnológicas em canais de abastecimento utilizados no cultivo de tambaqui

The use of biofilter of aquatics plants can be an alternative for the treatment and minimization of effluents generated in fish farming. The objective of this work was to evaluate the effect of water hyacinth (Eichhornia crassipes) in the improvement of the limnological variables of water of supply channels used for fish farming. The experiment was conducted in supply channels over a period of 60-days at sampling intervals of fifteen days. The channels were sectioned with screens. A density of 120 fish m-3was used. The sections were divided into stages, alternating with presence or absence of water hyacinth. It was not observed significant differences in the level of ammonia (p >0.05), alkalinity and hardness of the effluent in both treatment systems. However it was observed that water hyacinth was efficient in the removal of nutrients such as, phosphorus (first weeks of cultivation). The use of water hyacinth can be recommended in fish farming systems.

EFFECT OF THE ENVIRONMENTAL COLOR ON THE SOCIAL BEHAVIOR OF MALES OF BETTA SPLENDENS

O presente trabalho teve como finalidade a avaliacao do comportamento social de Betta splendens submetidos a ambientes com diferentes cores. A pesquisa teve duracao de 60 dias de experimentacao, onde foram utilizados 18 Bettas splendens, machos, distribuidos individualmente em 18 aquarios experimentais de 1,5 L de capacidade efetiva, sendo utilizados seis tratamentos, que foram as cores do ambiente (aquario), constando de: T1 – cor branca, T2 – cor verde, T3 – cor azul, T4 – cor vermelho, T5 – cor amarela e T6 – cor preta com tres repeticoes cada, e um animal para cada unidade experimental, dispostos num delineamento inteiramente casualizado em parcelas subdivididas. Em todos os tratamentos, nos dias de alimentacao, foi ofertada racao duas vezes ao dia (manha e tarde) em horarios pre-determinados, ate a aparente saciedade dos animais. A racao utilizada foi comercial especifica para a especie, com os mesmos padroes nutricionais em todos os tratamentos. Os parâmetros avaliados foram a Distribuicao na lâmina d’agua; Atividade locomotora; Confronto agonistico; Confronto agonistico com ameaca; Posicao da nadadeira dorsal e Abertura dos operculos. A coleta de dados foi realizada semanalmente de acordo com um padrao pre-estabelecido de comportamento. Os resultados obtidos foram submetidos a ANAVA e teste de Tukey a 5% de probabilidade. A cor do ambiente em aquarios experimentais influencia o comportamento social dos Bettas, sendo as cores branco e azul mais recomendadas a manutencao da especie, por amenizarem as interacoes agonisticas e o estresse.

Exigência de proteína bruta para juvenis de curimatã-pacu

The aim of this study was to determinate crude protein (CP) requirement to curimatã-pacu juveniles (Prochilodus argenteus). The experiment was conducted during 60 days in a completely randomized design, with four treatments (24.0, 28.0, 32.0 and 36.0% CP of diet) and five replications, where a hundred juvenile fishes (initial weight de 0.33 ± 0.01g), were distributed in twenty tanks (130L each). Each tank with five juveniles was considered an experimental unit, with water recirculation. Performance, heterogeneous growth, morphometric and physiological parameters, and economic viability of the rations according to the CP levels were evaluated. For the regression analysis, a linear increase in performance, heterogeneous growth and morphometric and physiological parameters with increased of the protein in rations were observed. When compared by the Tukey test (P>0.05), the best results were obtained with 36% CP. There was lower fish growth heterogeneity as the levels of CP in the diet increased. Thus, taking into consideration the economic viability it is recommended to use feed containing 36% of crude protein to curimatã-pacu juveniles.

Crescimento heterogêneo de tilápia do Nilo alimentados com resíduo de biscoito na dieta

O objetivo deste trabalho foi avaliar o efeito de quatro niveis da adicao de residuo de biscoito (0, 7.0, 14.0 e 21.0%) na dieta de juvenis de tilapia do Nilo sobre o crescimento heterogeneo, com peso inicial medio de 3,0±0,5g em um delineamento experimental inteiramente casualisado (DIC) com quatro tratamentos e cinco repeticoes, foram utilizados 100 animais peso medio inicial de 3,0±0,5g distribuidos em 20 aquarios experimentais de 130L cada onde permaneceram por 60 dias, foram alimentados tres vezes ao dia ate a aparente saciedade. Os peixes alimentados com 14% de residuo de biscoito apresentaram melhor crescimento homogeneo.

Restrição alimentar no desempenho de machos do peixe beta (Betta splendens)

The aim of this study was to evaluate the effects of alimentary restriction on Betta splendens performance. For the experiment, 24 males were used, with initial average weight of 0.55 ±0.06 grams, distributed in 24 experimental aquaria with 1.5 liters of water without aeration in a completely randomized design, with four treatments and six repetitions. The treatments were: T1 – daily fed animals (control), T2 - fed for six days and one day of restriction (6A/1R), T3 - fed for five days and two days of restriction (5A/2R) and T4 - fed for four days with three days of restriction (4A/3R). The fishes were fed twice a day at 08:00am and 4:00pm. The variables studied were: final weight (FW), weight gain (WG), alimentary conversion (FC), average feed consumption (CMR), total length (CTOTAL), standard length (CPADRAO) profile index (IPERFIL), condition factor (CF) and height. The results were submitted to variance analysis (ANOVA), and the means were compared by Tukey´s test at 5% of probability. No significant differences were observed for the following variables: water quality, survival, alimentary conversion and profile index. The best growth performance was observed when the feeding management of 6A/1R was applied.