Behavioral responses of freshwater prawn according to feeding management in mixed and monosex populations

Abstract

The effects of two feeding management methods (substrate spreading and feeding tray) were tested for Macrobrachium rosenbergii, evaluating their influence on behavior in mixed (Mi), monosex all-male (Mm) and monosex all-female (Mf) populations. Twelve experimental conditions, totaling 192 animals, with four repetitions each, were performed. Experimental units comprised eight 250 L aquariums (50 x 50 x 100 cm) with soft sand substrate. Behavioral data were collected by focal instantaneous sampling method. Substrate spreading triggered the most extensive behavioral level in all populations under analysis, featuring exploring, auto-grooming, crawling, inactivity, burrowing, agonism, swimming and feed ingestion, and revealed that the animals expressed better their behavior when feed was spread. Exceptionally, burrowing in Mm and agonism in Mf had similar level rates for the two feeding managements. Mf had the highest agonistic level when compared to that in Mm and Mi. Data in current analysis indicate that the spread feeding strategy favors animal welfare in all types of population compositions, except in Mf culture, with high agonistic levels in both forms of feeding management