Increased Production of Tank-Reared Macrobrachium rosenbergii THROUGH USE OF ARTIFICIAL SUBSTRATES1

The giant Malaysian prawn, Macrobrachium rosenbergii (de Man), is aggressive and cannibalistic when reared at high densities. In two experiments use of artificial substrates was tested as a means of increasing production. In experiment I, after 4 weeks average prawn mortality was 4 times greater in tanks (95 liters) not containing substrates than in tanks fitted with five-tiered horizontal substrate units. In experiment II the effects of substrates and substrate configuration on prawn production were examined in larger tanks (2.2 kl). Prawns reared in tanks containing either the horizontal or vertical substrates grew faster and had a higher survival than those reared in tanks not containing the substrates. In addition, feed utilization was less efficient and cannibalism became apparent at a much smaller size among prawns reared in tanks without substrates. Biomass production and survival were slightly greater among prawns reared in tanks containing a horizontal substrate configuration than among prawns in the vertical configuration.