INDIAN WHITE SHRIMP (FENERROPENAEUS INDICUS) CULTURE TWO TIMES A YEAR IN GWATAR SHRIMP FARM, IRAN

During the decade 1991-2001, culture of Indian White Shrimp grew rapidly in Iran due to high profitability, but afterwards suffered a decreasing trend with many farms still being idle after construction. The trend occurred mainly due to (1) increase in production costs with simultaneous decrease in international shrimp market price, (2) Agro-climatic conditions that favored only one crop a year, which is not profitable, and (3) fear about spread of disease as already experienced in the case of white spot disease in Khouzestan and Bushehr provinces. Based on these facts, we aimed in our study to increase production of the shrimp per year, to reduce days of culture (DOC) in second crop through nursery system, to control food conversion ratio (FCR), and to manage shrimp production in Gwatar shrimp farming complex. Six farms were selected, and in three we applied two crops a year production system using nursery for the second crop. In other three farms one crop was harvested. Shrimps in two-crop farms were kept 52 days of the second crop in nursery and then transferred to grow out ponds. All farms harvested before DOC 128. Mean productions per hectare in the first and second crop were 1794 and 1691kg, respectively. The FCR dropped from 1.6 in the first to 1.27 in the second crop. Total production per hectare per year reached 3485kg in two-crop farms. Shrimps in one-crop farms were harvested mainly at DOC 145. The mean production per ha/year and FCR of one-crop farms reached 2089kg and 1.65 respectively. We harvested around 47114kg of shrimps in each two-crop farm which was 17 tons more than one-crop farms. The results of this study showed that production of shrimps in two crops a year system could be continued with pre-designed schedules. We presented a time table for two crops a year culture system.