Abstract
Tracking experiments of silver carp Hypophthalmichthys molltrfx and bighead Aristickthys nobitis were carried out in Lake Donghu, Wuhan, China.
The swimming behaviors of the fishes were analyzed by means of telemetric method; The signal from an acoustic transmitter (ginger) carried by the fish was received by sonobuoys which were moored at three points on the surface of the water and was linked to a base station on a ship by radio. The position of the fish was determined in succession by the differences of the travelling times of sonic pulses from the fish to the buoys.
The results are summarized as follows;
1) Both fishes were slow in movement and showed the same swimming behaviors: Usually they swam at the speed of less than 30cm/s and stayed in the experimental area through the surveyed periods.
2) Relation between swimming time T (%) and swimming speed υ (cm/s) was represented'as T=1816υ-1.54.
3) Maximum Ievel of economic speed of the fishes was estimated to lie below 200cm/s.
