Volpato G L, Duarte C R A, Luchiari A C
Centro de Pesquisa em Bem-Estar Animal-RECAW, Laboratório de Fisiologia e Comportamento Animal, Departamento de Fisiologia, Instituto de Biociências, Universidade Estadual Paulista, Botucatu, SP, Brazil.
Braz J Med Biol Res. 2004 Apr;37(4):479-83. doi: 10.1590/s0100-879x2004000400004. Epub 2004 Mar 23.
We investigated the effects of environmental color on the reproductive behavior of Nile tilapia, Oreochromis niloticus. Two environmental colors were tested by covering the aquarium (60 x 60 x 40 cm) with white (12 groups) or blue (13 groups) cellophane and observing reproductive behavior in groups of 2 males (10.27 +/- 0.45 cm) and 3 females (10.78 +/- 0.45 cm) each. After assignment to the respective environmental color (similar luminosity = 100 to 120 Lux), the animals were observed until reproduction (identified by eggs in the female's mouth) or up to 10 days after the first nest building. Photoperiod was from 6:00 h to 18:00 h every day. Food was offered in excess once a day and water quality was similar among aquaria. Daily observations were made at 8:00, 11:00, 14:00 and 17:00 h regarding: a) latency to the first nest, b) number of nests, c) gravel weight removed (the male excavates the nest in the bottom of the aquarium), d) nest area, and e) mouthbrooding incubation (indication of reproduction). The proportion of reproducing fish was significantly higher (6 of 13) in the group exposed to the blue color compared the group exposed to the white color (1 of 12; Goodman's test of proportions). Moreover, males under blue light removed significantly larger masses of gravel (blue = 310.70 +/- 343.50 g > white = 130.38 +/- 102.70 g; P = 0.01) and constructed wider nests (blue = 207.93 +/- 207.80 cm(2) > white = 97.68 +/- 70.64 cm(2); P = 0.03) than the control (white). The other parameters did not differ significantly between light conditions. We concluded that reproduction in the presence of blue light was more frequent and intense than in the presence of white light.
我们研究了环境颜色对尼罗罗非鱼（Oreochromis niloticus）繁殖行为的影响。通过用白色（12组）或蓝色（13组）玻璃纸覆盖水族箱（60×60×40厘米）来测试两种环境颜色，并观察每组2条雄性（体长10.27±0.45厘米）和3条雌性（体长10.78±0.45厘米）的繁殖行为。在分配到各自的环境颜色（相似光照度=100至120勒克斯）后，观察这些动物直至繁殖（以雌鱼口中有卵来确定）或直至首次筑巢后10天。光周期为每天6:00至18:00。每天提供一次过量食物，各水族箱水质相似。每天在8:00、11:00、14:00和17:00进行观察，内容包括：a）首次筑巢的潜伏期，b）筑巢数量，c）移除的砾石重量（雄性在水族箱底部挖掘巢穴），d）巢穴面积，以及e）口孵育（繁殖的迹象）。与暴露于白色的组（12组中的1组；古德曼比例检验）相比，暴露于蓝色的组中繁殖鱼的比例显著更高（13组中的6组）。此外，蓝光下的雄性移除的砾石质量显著更大（蓝色=310.70±343.50克＞白色=130.38±102.70克；P=0.01），并且建造的巢穴比对照组（白色）更宽（蓝色=207.93±207.80平方厘米＞白色=97.68±70.64平方厘米；P=0.03）。其他参数在不同光照条件下没有显著差异。我们得出结论，蓝光环境下的繁殖比白光环境下更频繁、更强烈。
