Growth Performance of Minute Duckweed (Lemna perpusilla) In An Integrated Common Carp (Cyprinus carpio) Closed Recirculation Aquaculture
Tjandra Chrismadha, Fachmijani Sulawesty, Awalina, Yayah Mardiati, Endang Mulyana and Mey Ristanti Widoretno 2014

Tjandra Chrismadha, Fachmijani Sulawesty, Awalina, Yayah Mardiati, Endang Mulyana and Mey Ristanti Widoretno. 2014. Growth Sustainability of aquaculture in Indonesia has been challenged by expensive feed and limited water. One effort to solve those problems integratively is by application of aquatic plant which can be function both as natural or substitution feed as well as water quality fitoremediation agent. A trial has been carried out to utilize minute duckweed (Lemna perpusilla) for water fitoremediator in a closed resirculation aquaculture of common carp (Cyprinus carpio), while the biomass produced was stocked back in for partially substitution of commercial feed. The trial ponds consisted of 4 concrete ponds and 8 tarpaulin ponds arranged to obtain a serial water flow by means of a submersible pump of 6000 L/hour capacity. Juvenile of the fish was placed in the concrete ponds 100 fishes each, and let to grow based on commercial pellet and mixed fresh lemna biomass for 23 weeks. At the same time, the duckweed was reared in the tarpaulin ponds in a controlled density at 700 g/pond by means of regular harvest 3 times a week. This article reports the growth and productivity performance of the duckweed in the trial system calc ulated according to the data of the observed regular biomass harvested. While nutrition values of the duckweed biomass was obtained from regular sampling every 4 weeks. During the 21 weeks trial period, the duckweed was able to grow continually utilized the common carp aquaculture waste as the nutrient source, in which the specific growth rate values ranged of 12 25% per day. In the mean time, the duckweed productivity was accounted of 0.028 0.053 kg/m2/day (equivalent to 6.14 11.61 ton dry matter/Ha/year), while the protein content was 11 32% of the dry weight. This result indicates the potential of ducweed for alternative feed in aquaculture, even though some funther research still being needed to find out the optimal condition for better growth and biomass quality of the duckweed