RESUMEN
Abstract The aim of this study was to evaluate the effect of different colors in development and survival of catfish Lophiosilurus alexandri larvae, as well as over the visual ability of the handler. Larvae were placed in 5 L-aquariums at a density of 7 larvae L-1 , and aquariums had different colors, and were: green and blue (light colors); brown and black (dark colors). The final development; survival, total and standard length, weight and biomass of the larvae were similar in all colored aquaria. The highest mortality occurred during the first days after hatching, declining over the period, when it is observed the larval development, indicating that care should be necessary in the first few days. During cleaning handling, the accidental catch of larvae was higher in black aquariums. In the first days of life, due to the fragility of the larvae, it is possible to verify that between the second and third day occur the greatest mortalities. The number of accidentally captured larvae was lower than the mortality, suggesting that the high mortality in early larval life is not influenced by the handler management. The catfish L. alexandri larvae should be cultivated in aquariums that allow a good contrast between the larvae and the background, to avoid accidental capture of larvae by the handler. It is suggested to avoid the use of dark and black aquariums.
Resumo O objetivo deste experimento foi avaliar o efeito de diferentes cores de aquários no desempenho e sobrevivência das larvas do bagre Lophiosilurus alexandri , bem como sobre a capacidade visual do tratador. As larvas foram colocadas em estocadas em 5 L-aquários na densidade de 7 larvas L-1, e aquários apresentaram cores diferentes e foram distribuídos a seguir: verde e azul (cores claras); marrom e preto (cores escuras). O desempenho final; a sobrevivência, comprimento total e padrão, peso e biomassa das larvas foram semelhantes entre os aquários coloridos. A maior mortalidade ocorreu durante os primeiros dias após a incubação, em declínio ao longo do período, quando se observa o desenvolvimento larval, indicando que os cuidados devem ser redobrados nos primeiros dias. Durante o manejo de limpeza, a captura acidental de larvas foi maior nos aquários pretos. Nos primeiros dias de vida, devido à fragilidade das larvas, é possível verificar que entre o segundo e o terceiro dia ocorrem as maiores mortalidades. O número de larvas capturadas acidentalmente foi menor do que a mortalidade, sugerindo que a alta mortalidade na vida larval não é influenciada pelo manejo do manipulador. As larvas de bagre L. alexandri devem ser cultivadas em aquários que permitem um bom contraste entre as larvas e o fundo, para evitar a captura acidental de larvas pelo manipulador. Sugere-se que evite o uso de aquários escuros e pretos.
Asunto(s)
Animales , Bagres/fisiología , Color , Animales de Zoológico/fisiología , Bagres/crecimiento & desarrollo , Longevidad , Animales de Zoológico/crecimiento & desarrolloRESUMEN
Abstract The aim of this study was to evaluate the effect of different colors in development and survival of catfish Lophiosilurus alexandri larvae, as well as over the visual ability of the handler. Larvae were placed in 5 L-aquariums at a density of 7 larvae L-1 , and aquariums had different colors, and were: green and blue (light colors); brown and black (dark colors). The final development; survival, total and standard length, weight and biomass of the larvae were similar in all colored aquaria. The highest mortality occurred during the first days after hatching, declining over the period, when it is observed the larval development, indicating that care should be necessary in the first few days. During cleaning handling, the accidental catch of larvae was higher in black aquariums. In the first days of life, due to the fragility of the larvae, it is possible to verify that between the second and third day occur the greatest mortalities. The number of accidentally captured larvae was lower than the mortality, suggesting that the high mortality in early larval life is not influenced by the handler management. The catfish L. alexandri larvae should be cultivated in aquariums that allow a good contrast between the larvae and the background, to avoid accidental capture of larvae by the handler. It is suggested to avoid the use of dark and black aquariums.
Resumo O objetivo deste experimento foi avaliar o efeito de diferentes cores de aquários no desempenho e sobrevivência das larvas do bagre Lophiosilurus alexandri , bem como sobre a capacidade visual do tratador. As larvas foram colocadas em estocadas em 5 L-aquários na densidade de 7 larvas L-1, e aquários apresentaram cores diferentes e foram distribuídos a seguir: verde e azul (cores claras); marrom e preto (cores escuras). O desempenho final; a sobrevivência, comprimento total e padrão, peso e biomassa das larvas foram semelhantes entre os aquários coloridos. A maior mortalidade ocorreu durante os primeiros dias após a incubação, em declínio ao longo do período, quando se observa o desenvolvimento larval, indicando que os cuidados devem ser redobrados nos primeiros dias. Durante o manejo de limpeza, a captura acidental de larvas foi maior nos aquários pretos. Nos primeiros dias de vida, devido à fragilidade das larvas, é possível verificar que entre o segundo e o terceiro dia ocorrem as maiores mortalidades. O número de larvas capturadas acidentalmente foi menor do que a mortalidade, sugerindo que a alta mortalidade na vida larval não é influenciada pelo manejo do manipulador. As larvas de bagre L. alexandri devem ser cultivadas em aquários que permitem um bom contraste entre as larvas e o fundo, para evitar a captura acidental de larvas pelo manipulador. Sugere-se que evite o uso de aquários escuros e pretos.
RESUMEN
objective: To study the properties of keepers treated with different methods. Methods: Eighteen Z 3 magnetic attachments were divided into three groups at random. Cobalt chromium alloy was used for root cap. The keepers in the first group were cast to the caps, those in the second group were welded to the caps by Nd:YAG laser welding apparatus. Keepers in the third group were untreated. Universal testing machine was adopted to measure the breakaway retention of the attachments. The roughness of keeper surfaces was measured by roughness tester. Results: No statistical difference was observed as to the breakaway retention between magnetic attachments and laser welded coping keeper or between those and cast coping keepers. But retention of the keepers in the two groups was slightly lower than that of untreated keepers. Defects of pits were found on the surfaces of the cast coping keepers. The surface smoothness of the cast coping keepers was inferior to that of the laser welded coping keepers. Conclusion: Laser welded keepers and cast coping keepers can meet clinical demands for the use of magnetic attachments.