| Title |
Effect of Water Velocity on Foraging Behavior of Planktivore on Zooplankton in Aquatic Ecosystems |
| Authors |
박배경 ( Bae Kyung Park ) ; 박석순 ( Seok Soon Park ) |
| Keywords |
Aquatic ecosystem; Flowing water environment; Focal velocity; Pseudorasbora parva; Saltatory searching |
| Abstract |
Foraging behaviour of false dace, Pseudorasbora parva, was investigated in water flowing at various velocities with the existence of a cavity for rest. The pursuit comprised three succeeding processes such as, approaching, chasing and attacking. Angles between the fish body and the water flow direction and swimming speeds increased in the latter stages of approaching, chasing and attacking. All pursuit angles, swimming speeds and distances increased with flow velocity and peaked at the flow velocity of 7 ㎝/sec. At higher velocities, however, the fish avoided the use of much energy against the large drag force. The probability of capture and the feeding rate steadily decreased with increasing flow velocity. Under the fast flow, the fish adjusted their swimming speed to get the optimum velocity relative to the flowing water for the energetic budget. Fish spent more time in the cavity as flow velocity increased to avoid the energy expenditure necessitated by the high velocity. |