Ingestão de náuplios de artêmia por larvas de Macrobrachium rosenbergii submetidas a diferentes espectros de luz

Abstract

The success of crustacean cultivation depends, among other factors, on the control of abiotic parameters. Larviculture is characterized by a complex phase that requires adequate conditions for its cultivation. The larvae cultivation environment must be maintained with balanced parameters that allow swimming and feeding activity. Macrobrachium rosenbergii larvae have positive phototaxis and light is a factor that determines the development of these larvae, due to the luminosity it is directly related to the identification and capture of food. Under ideal conditions, light can favor increased food consumption. The relationship between the light spectra and the shrimp life cycle has been considered as a variable that can affect their cultivation. Thus, the aim of this study was to evaluate the ingestion of artemia nauplii by M. rosenbergii larvae submitted to the aspects of blue, red and natural light. The experiment was carried out at the Shrimp Laboratory of the Federal University of Recôncavo da Bahia (UFRB). The design was completely randomized in a 10x3 factorial scheme (stage x light spectrum) with ten repetitions each, carried out in 60 mL pots lined in black, containing 40 mL of water in salinity 12. These were placed inside polyethylene boxes. Larval stages were identified before each analysis. The density for the analysis was one larva / pot, fed with 5 artemia nauplii / mL, totaling 200 nauplii per pot. After 24 hours, the larvae were removed and the remaining nauplii counted. The amount consumed was determined by the difference between the final number and the initial number of nauplii in the pot. This process was carried out for all larval stages (II to XI) on different days. The results of this study demonstrate that the light spectra play an important role and capture and consumption of artemia nauplii. Among the treatments analyzed there was a significant difference between the natural light treatment and the red light spectrum, however there was no difference between natural light with the blue light spectrum and between the red and blue spectra. Thus, our results suggest that natural light and the blue spectrum provide greater intake of artemia nauplii by M. rosenbergii larvae.