ANALYSIS OF MEKONG GIANT CATFISH BEHAVIOR USING A DATA LOGGER

Abstract

Temperature and depth data logger was attached to Mekong giant catfish to observe their swimming behavior in a rearing pond. Four artificial seed reared in the Karasin Freshwater Research Station, Thailand were used to obtain the body temperature and fish position on water depth. The fish were anesthetized and implanted with a data logger (DST milli, Star-oddi Co., Iceland) into the body cave on 2 May 2002. One data logger was retrieved and body temperature and depth data were obtained for about one month. The fish moved to relatively deeper layer after sunrise and stayed there in the morning. In the afternoon the fish became active gradually and began to move vertically. After sunset the fish got more active and moved vertically from the surface to the bottom of the pond until the next sunrise. At sunrise the fish stopped the vertical movement. It seems that Mekong giant catfish have a nocturnal characteristic and get most active at twilight.