Study on feeding habits of Mekong giant catfish in Mae peum Reservoir, Thailand

Abstract

In order to recapture Mekong giant catfish, we developed an automatic fish recapture system (AFR system). The AFR system causes the free-ranging fish to float at the scheduled time. We have conducted experiments on Mekong giant catfish in the Mae peum reservoir, Thailand. We used 7 cultivated young catfish, whose total length ranged from 76.5 cm to 86.5 cm. After we attached the AFR system to the catfish, we released them into the reservoir in August (one catfish), October (three catfish) and December (three catfish) of 2004. The AFR systems were scheduled to cause the catfish to float after four to eight days. The recovery percentage of both the catfish and the AFR systems was 43 %. The recovery percentage of only the AFR systems was 29 %. The percentage of loss of all the catfish and the AFR systems was 29 %. We also examined the stomach contents of the catfish with a microscope and found some zooplankton and phytoplankton. The total number of the zooplankton in the stomach contents in October was 1288 individuals and the most, and those in August and December were 33 and 34 individuals respectively and least.