RESUMO. A dinâmica de fornecimento de peixes para a população mundial passa por um momento de redução da pesca extrativista e aumento na produção aquícola, à qual no Brasil é favorecida pela grande disponibilidade de recursos hídricos, a variedade de espécies, clima favorável e pelo aumento na demanda por essa fonte de proteínas. Apesar disso, o consumo de peixes pela população brasileira é ainda pequeno, atingindo em média, cerca de 9 kg/habitante/ano, abaixo do recomendado pela FAO (12 kg/habitante/ano). O objetivo do presente trabalho foi avaliar o panorama atual do consumo de peixes pela população, destacando os motivos por trás de tal consumo, como preferências alimentares e questões socioeconômicas. Os resultados apontam preferência por carnes bovinas (48,5%) e de aves (25,2%) antes da escolha por peixes (19,2%), sendo que a população consome peixes em frequências discrepantes em diferentes regiões, mas em geral em baixa frequência, independentemente da origem do pescado e do poder aquisitivo da mesma. Os resultados também apontam que os setores econômicos e de comercialização da pesca e da aquicultura devem divulgar as informações desse mercado de maneira mais eficiente, assim como estimular a formulação de novos produtos comercializados, visando o aumento do consumo de peixes pela população.
The banded cichlid (Herus severus) is an Amazonian species with potential as ornamental fish, however basic handlings as quantity and feeding frequency as well as stocking density in larviculture are still unknown in order to allow the rational production of this species in captivity. Then the objective was to evaluate the amount of food, feeding frequency and stocking density during the larviculture of Herus severus. Therefore, two experiments were conducted: the first assessed the food concentration (100, 150, 200, 250 and 300 Artemia larvae-1) and feed rate (2 or 4 meals day-1), and the second experiment evaluated different stocking densities (1, 5, 10, 15, 20 larvae L-1) with four replications each. Feeding of 250 nauplii larva day-1 distributed in four daily meals promoted the highest weight, length, specific growth rate, weight gain and survival. In the second experiment, reduction in growth was observed with increased in density due to lower concentrations of dissolved oxygen and elevated total ammonia from 5 larvae L-1. Thus, to promote the rational cultivation of the Banded cichlid larvae in captivity, the species should be reared at 5 larvae L-1 fed with 250nauplii distributed along 4 daily meals.
This study evaluated the growth and survival of Betta splendens larvae exposed to different salt concentrations (NaCl 0, 2, 4, 6 and 8 g L-1) and stocking densities (1, 5, 10 and 15 larvae L-1) during 20 days. A completely randomized design in a 5x4 factorial scheme with three replications was used, and the fish reared in static system. At the end of the experiment were evaluated the final weight, total length, group uniformity, specific growth rate and survival. Total larvae mortality was observed in treatments with 4, 6 and 8 g L-1, demonstrating the susceptibility of this specie for these concentrations. However, the salinized water with 2 g L-1 promotes longer larvae when fish were maintained in densities of 10 and 15 larvae L-1. Further, there were no interactions between the addition of salt and stocking density for the other parameters. However, beneficial effects of salinized water (2 g L-1) were observed as better growth performance and survival of larvae. Regarding the stocking density, apart from addition of salt, the larvae present best development at density of 5 larvae L-1. Therefore, the use of salinized water (2 g L-1) and stocking density of 5 larvae L-1 is recommended for the Betta splendens larviculture.
O objetivo do trabalho foi avaliar a eficácia de sementes de abóbora e mamão desidratadas e moídas, no controle de helmintos parasitos de Astyanax cf. zonatus. Sessenta peixes foram distribuídos em doze recipientes, um peixe/litro. O experimento constituiu de quatro tratamentos e três repetições: TJ = peixes deixados em jejum; TRC = peixes alimentados com ração comercial; TSA = peixes alimentados ad libitum com abóbora, e TSM = peixes alimentados ad libitum com mamão. Após sete dias de alimentação, todos os peixes foram pesados, e o sangue foi retirado para extensão sanguínea. A eficácia foi determinada, verificando a presença de parasitos nas brânquias, no estômago e no intestino. Os peixes do TJ e TSM apresentaram perda de peso (39% e 25%, respectivamente). O TSA apresentou melhor eficácia no controle de nematóides do intestino e do estômago (95,26% e 92,48%). No controle de monogenéticos TSM promoveu 72% de eficácia. Na hematologia observou-se aumento de monócitos nos peixes do TSM e os valores de eosinofilos diminuíram nos tratamentos TSA, TSM e TRC. Assim pode-se concluir que a alimentação com abóbora pode ser utilizado como um controle alternativo eficaz de nematóides intestinais do lambari.
Summary The objective of this study was to evaluate the effects of different live foods, (Artemia sp. and Moina minuta), and different stocking densities on the larval rearing success of the leaf fish, Monocirrhus polyacanthus. A completely randomized factorial design (3 × 3; three replicates) was used. Two subsequent experiments were performed for each live food, using three food densities (100, 200 and 300 prey per larva) and three stocking densities (10, 15 and 20 larvae L−1). Fish were fed twice a day. Water quality parameters pH (4.08–4.02), dissolved oxygen (3.7–3.6 mg L−1), temperature (27.9–27.8°C), conductivity (147.2–127.4 μs cm−1) and total ammonia (0.78–0.38 μg L−1) were determined. Weight gain, specific growth rate (SGR), body mass, relative condition factor and survival were evaluated. The water quality was influenced by the live food and stocking densities. Fish fed M. minuta showed better weight gain, specific growth ratio (SGR), biomass gain, relative condition factor and survival than in the other treatment. Artemia sp. showed no improved influence on the larvae performance subjected to different treatments. The beneficial role in growth and survival of leaf fish larva when fed with M. minuta is discussed.
RESUMOO objetivo deste trabalho foi avaliar a eficácia da formalina e sulfato de cobre no controle de monogenéticos em juvenis de Hemigrammus sp e seu efeito na contagem diferencial de leucócitos. Utilizou-se um delineamento inteiramente casualizado com 5 tratamentos e 3 repetições. Todos os tratamentos tiveram duração de três dias e corresponderam a: T1, controle; T2 e T3 banho por imersão de uma hora em formalina, em duas concentrações uma de 0,25 ml e outra 0,1 ml formalina L ). Após o período experimental observou-se que em T2 ocorreu 100% de mortalidade. O T3 e T5 proporcionaram eficácia de 100%, porém os peixes apresentaram intoxicação e mortalidades de 66 e 80%, respectivamente. T4 apresentou eficácia de 77,7% e diminuição dos índices parasitológicos: número total de parasitos de 11,3±9, intensidade média de infecção de 3,2±2 e prevalência de 47,1%. Quanto aos leucócitos observou-se que no T3, T4 e T5 ocorreram diferenças na proporção de linfócitos, monócitos e neutrófilos em relação ao controle. O CuSO 4 e a formalina reduzem a carga parasitária, mas apresentaram-se tóxicos nas maiores concentrações. PALAVRAS-CHAVE: CuSO 4 , formol, monogênias, tratamento Evaluation of formalin and copper sulfate on monogenetic parasite (Urocleidoides sp.) of Hemigrammus sp. (Osteichthyes: Characidae) juveniles ABSTRACTThe objective of this study was to evaluate the effectiveness of formalin and copper sulphate to control monogeneans in juvenile Hemigrammus sp and its effect on leukocyte count. We used a completely randomized design with five treatments and three replications. All treatments lasted for three days and consisted of: T1, control; T2 and T3 immersion bath for one hour in formalin, an of two concentrations of 0.25 ml formalin and the other 0.1 ml L ). After the experimental period was observed that T2, 100% mortality. The T3 and T5 provided 100% efficiency, however, fish presented mortalities and intoxication of the 66 and 80% respectively. T4 showed an efficacy of 77.7% and decrease in parasitological indices: total number of parasites of11, 3 ± 9, mean infection intensity of 3.2 ± 2 and a prevalence of 47.1%. As the leukocytes was observed that at T3, T4 and T5 occurred differences in the proportion of lymphocytes, monocytes and neutrophils as compared to control. The CuSO 4 and formalin reduce the parasite load, but presented to be toxic at higher concentrations.
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