Kajian Kontribusi Pakan Alami dan Buatan Serta Variasi Musim Pada Performansi Pertumbuhan Juvenil Udang Penaeus monodon yang Dipelihara Dalam Tambak Air Payau

Abstract

Two pond experiments were carried out to evaluate nutrition contribution of natural and formulated feeds on growth performance of juvenile black tiger shrimp, Penaeus monodon in seasonal variations. Forty unfed shrimp and fed shrimp groups (initial mean individual weight 0,90 ± 0,08 g) were used in the study. The juveniles were individually placed in the transportable compartments of each pen (10 animals/m2/pen) installed within a 1500 m2 fertilized earthen pond and reared for 60 days in Experiment 1 (season with greater rainfall) and another 60 days in Experiment 2 (season with lower rainfall). A range of water salinity in Experiment 1 and 2 were 6– 7 ppt and 17–19 ppt, respectively. The shrimp growth performances were regularly observed every 15 days during the study and at the end of study, survival rates of shrimp were determined. Results showed that there were a significant difference (P<0.01) in growth performance (weight gain) between the unfed-shrimp (5,1–6,9 g) and fedshrimp groups (12,5–14,1 g). Seasonal variations in rainfall did not seem to influence growth and survival performance of the shrimps. It was found that the presence of natural food in the pond was important to boost shrimp production and approximately 36% and 54% of growth of shrimp in Experiments 1 and 2, respectively, were supplied by natural food. A synergism of the nutrition of natural food and formulated diets utilized by shrimp cultured under pond conditions was a proof of complementary and balance of both feed nutrition to produce the shrimp faster growths. Although this study was performed using a pond pen model on a small scale, the results obtained have provided useful information on the significant potential of natural food in a commercial semi-intensive shrimp farming regardless seasonal variations in rainfall.