In this study, the effect of initial heterogeneity of weight and density on heterogeneous growth (HetG) evaluated by the coefficient of the variation of weight in the young Nile tilapia Oreochromis niloticus of the territorial species was tested. Fish were maintained in a glass aquarium (8 and 2 L of water) with two levels of initial heterogeneity of weight: low and high, under two density conditions: low and high, thus constituting four conditions (six replications for each). Initially, the weights of the animals were taken after 8, 16, 22 and 30 days (end of experiment). The results, evaluated by the non-parametric test of Kruskal-Wallis, demonstrated that in the groups where the animals were stored under high initial HetG, there was a reduction of the same and that in the groups where the animals were stored under high density, there was exacerbation or maintained high values of HetG. High density in association with high initial heterogeneity caused more exacerbation of HetG in such a way that the density appeared to be a determining factor for exacerbation or the maintenance of high values of HetG, whereas the initial heterogeneity of the weight could be a secondary factor.Keywords: fish, behavior, density, heterogeneous growth. RESUMO Crescimento heterogêneo em juvenis de Tilápia-do-nilo Oreochromis niloticus:efeito da heterogeneidade inicial de peso e da densidade Neste trabalho, testou-se o efeito da heterogeneidade inicial de peso e da densidade sobre o crescimento heterogêneo (CHet, avaliado pelo coeficiente de variação do peso) em juvenis de tilápia-do-Nilo Oreochromis niloticus, espécie territorial. Os peixes foram mantidos em aquários de vidro (8 e 2 L d'água) com dois níveis de heterogeneidade inicial de peso: baixo e alto, sob duas densidades: baixa e alta, configurandose quatro condições (6 réplicas cada uma). Os pesos dos animais foram tomados no início, aos 8, 16, 22 e 30 dias (final do experimento). Os resultados, avaliados pelo teste não paramétrico de Kruskal-Wallis, demonstraram que nos grupos em que os animais foram estocados com alto CHet inicial houve redução e que nos grupos em que os animais foram estocados em alta densidade houve exacerbação ou manutenção dos altos valores de CHet. A alta densidade quando associada à alta heterogeneidade inicial provocou maior exacerbação do CHet de forma que a densidade parece ser um fator determinante da exacerbação ou da manutenção de altos valores de CHet, enquanto a heterogeneidade inicial de peso pode ser um fator secundário.Palavras-chave: peixe, comportamento, densidade, crescimento heterogêneo.
To evaluate the possible toxicity of the aqueous extract of Echinodorus grandiflorus in pregnant rats, animals were distributed in groups treated with 250, 500 and 1,000 mg/kg/day, by gavage, and a control group received saline solution. The treatment was carried out for 15 consecutive days, remaining during mating and until the 14(th) day of gestation. On the 15(th )day, pregnant animals were euthanized by exsanguination under anesthesia. A blood sample was destined to the hematological and biochemical analysis. The ovaries, liver, kidneys, spleen, and adrenal glands were removed and weighed. Liver, kidneys and spleen were processed for histopathological analysis. The number mated, cohabitated and pregnant rats were counted as well as the corpora lutea, implants, resorptions, and live and dead fetuses. Fetus body weight and placenta were measured. Treatment with 1,000 mg of extract caused anemia, leukocytosis, and an increase in AST and in cholesterol. The liver of animals treated with the two higher doses exhibited discrete inflammatory reaction, located mainly at the stroma which supports the portal space; in the kidneys of animals of T-500 and T-1000 groups there was an expressive decrease in the capsular space, and focal areas of vasodilatation and congestion, as well as a discrete hyalinization, and in the spleen of T-1000 group the red pulp presented excessive pigmentation suggestive of hemosiderin. There were no alterations in reproductive parameters, in fetus external morphology or in placenta weight. In conclusion, the extract causes maternal toxicity, though it does not alter the reproductive performance.
O Jardim Botânico da Universidade Federal de Juiz de Fora (JB-UFJF) é considerado o maior fragmento de mata atlântica urbano do mundo, e porta uma área de 845.000 m². Levando em consideração que fatores abióticos influenciam a entomofauna local e que este ambiente é voltado para ações em educação ambiental, foram demarcados três transectos no interior da mata e realizadas 12 coletas mensais em 2016. Um total de 5.459 insetos foram amostrados, subdivididos em oito ordens e 84 famílias com predominância Acidental, calculada pelo Índice de Dajoz. A presença de insetos na área de estudo pode estar relacionada com a complexidade ambiental, a qual é importante para a existência da maior diversidade, em decorrência das condições mais favoráveis como abrigo, local para forrageamento e reprodução influenciadas principalmente pela temperatura e pela umidade relativa do ar do JB-UFJF.
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