Produção de Dendrocephalus brasiliensis Pesta, 1921 alimentado com Chlorella vulgaris em sistema experimental de cultivo

Abstract

This study aimed to investigate the feeding behavior and productivity of Dendrocephalus brasiliensis in algal different densities and experimental cultivation conditions. The experimental design was completely randomized with two treatments (Chlorella vulgaris: 270,000 and 2,700,000 cel mL-1), each replicated four times. The experiments were performed in a two-liter aquaria, with 10 animals per liter, and divided into two stages: (I) filtration and ingestion rates on three ages and photoperiod, with 12 hours of time per period under controlled conditions; and (II) checking during 15 days of culture, and the growth time of sexual maturation in semi-controlled environment. For all ages, filtration rates were higher in the diet with lower algae concentrations (3.93, 8.23 and 11.49 mL ind-1 h-1), however, consumption was greater at the higher concentration of food (3,958,000, 9,635,000 and 13,292,000 cel ind-1 h-1). Regarding to photoperiod, the filtration has been increased (13.95 mL ind-1 h-1) and ingestion (14,343,000 cel ind-1 h-1) in the dark. The greatest length (13.1 mm) and the beginning of the adult stage were found in the diet with the greatest algae concentration. According to the results, C. vulgaris concentration 2,700,000 cel mL-1 was the best food condition for D. brasiliensis and should, preferably, be provided at the beginning of the evening.