Environmental color affects Nile tilapia reproduction
Braz. j. med. biol. res
;
37(4): 479-483, Apr. 2004. tab, graf
Artículo
en Inglés
| LILACS
| ID: lil-357104
ABSTRACT
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 600 h to 1800 h every day. Food was offered in excess once a day and water quality was similar among aquaria. Daily observations were made at 800, 1100, 1400 and 1700 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 cm² > white = 97.68 ± 70.64 cm²; 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.
Texto completo:
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Índice:
LILACS (Américas)
Asunto principal:
Reproducción
/
Color
/
Cíclidos
/
Ambiente
Límite:
Animales
Idioma:
Inglés
Revista:
Braz. j. med. biol. res
Asunto de la revista:
Biologia
/
Medicina
Año:
2004
Tipo del documento:
Artículo
/
Congreso y conferencia
/
Documento de proyecto
País de afiliación:
Brasil
Institución/País de afiliación:
Universidade Estadual Paulista/BR
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