Data/hora: 08/06/2024 12:43:22

Provedor de dados: | 5
País: | France
Título: | L'élevage larvaire intensif du loup Dicentrarchus labrax. Influence de la lumière, de la densité en proies et de la température sur l'aluminium, sur le transit digestif et sur les performances zootechniques
Autores: | Ronzani Cerqueira, Vinicius.
Data: | 1986
Ano: | 1986
Palavras-chave: | Food; Prey; Light; Zootechnical; Digestive transit; Temperature; Dicentrarchus labrax; Intensive rearing; Sea bass.
Resumo: | Several sea bass-rearing experiments were performed from hatching trough metamorphosis. The rearing units employed were 500 1 polyester tanks, where flow rate and temperature of seawater, light and suitable food (rotifer and artemia) were controlled. Stock density ranged between 50 and 100 larvae per liter.  Individuals held in tanks with internal black walls developed faster and had a greater survival rate than those in white tanks. This suggests that a better contrast between preys and background assists the larvae to see food organisms more clearly.  The sea bass larvae search for food is based only in vision and not trought mechanoreceptors or chemoreceptors. It was very difficult to evaluate the light intensity (50-5000 lux) influence on feeding, growth and survival. The larvae that were reared under 9 h photoperiod had a greater survival than those kept under continuous light and the opposite happened in relation to growth. Until 30 days after hatching, sea bass presented a regular feeding rhythm in spite of different photoperidods .  Higher food densities increased gastric evacuation rates and decreased food assimilation to 35 day old larvae. Eventhough, no significant increment was observed on feeding intensity.  The larval growth were positively correlated with the three water temperatures tested (15, 20 and 25°C). The same effect was observed on gastric evacuation and food consumption. Normal swim bladder development had a positive correlation with shorter photoperiods and with continuous darkness.
Tipo: | Text
Idioma: | Francês
Identificador: | http://archimer.ifremer.fr/doc/1986/these-1676.pdf
Editor: | Aix-Marseille 2
Relação: | http://archimer.ifremer.fr/doc/00000/1676/
Formato: | application/pdf