Hydrodynamic Disturbance and Zooplankton Swimming Behavior

Laurent Seuront ； Hidekatsu Yamazaki ； Sami Souissi

《Zoological Studies》 43卷2期 (2004/04) Pp. 376-387

並列摘要

Using a novel experimental setup that generates a realistic range of turbulence intensities, we investigated (i) the ability of zooplankton organisms to swim against a gradient of turbulence, and (ii) the qualitative and quantitative nature of their swimming behavior after shortterm exposure to different intensities of turbulence. We used the cladoceran, Daphnia pulicaria, and the calanoid copepod, Temora longicornis, as model animals. First, both species increased their escape reactions with increasing turbulence intensity. However, this effect was significantly lower in T. longicornis. Second, swimming speed generated to reach the light source exceeded the turbulent velocities by up to 4-fold in D. pulicaria and 14-fold in T. longicornis. The swimming patterns of T. longicornis indicated a strong adaptation of this species to highly turbulent environments. Fractal analysis showed that the complexity of the swimming paths of D. pulicaria increased with the intensity of turbulence, and that this species exhibited a hysteretic cycle of 3 to 5 min for recovery from the prior swimming behavior. The implications on our findings on zooplankton trophodynamics, including predation vulnerability, encounter rates, and sensorial arguments, are discussed.

並列關鍵字

Zooplankton ； Behavior ； Turbulence ； Fractals ； Intermittency