Mekong giant catfish tracking project 2003 in the Mekong River

Abstract

Mekong giant catfish Pangasianodon gigas is one of the largest freshwater fish in the world. The fish is endemic to the Mekong basin and becomes high-degree endangered species listed in the IUCN Red List. Nevertheless little is known of the behavior. Ten Mekong giant catfish (TL : 76.5 to 88.5 cm, BW : 3.5 to 5.8 kg) were implanted with coded ultrasonic transmitters (Coded V16, Vemco Ltd.). Five monitoring receivers (VR1, Vemco Ltd.) were installed at Kong Chiam, Nakhon Phanom, Sri Chianmai, Sang Khong, and Chiang Khong along the Mekong River. The fish were released at Nakhon Phanom on 11 May, 2003. Three fish were recaptured by fishermen using set nets. One of the fish was recaptured at 100 km upward from the release point one week after release. This shows high performance of upward swimming of Mekong giant catfish in the Mekong River. Since 24 May, 2003, all fish are missing, unfortunately. Currently, the receivers are still waiting for the fish's coming.