Swimming in formation in krill (Euphausiacea), a hypothesis: dynamics of the flow field, properties of antennular sensor systems and a sensory-motor link
The act of swimming in formation by species such as Euphausia superba , Antarctic krill, is assumed to be regulated by a sensitivity to the characteristic and spatially elaborate flow field produced by this species of shrimp. We used a related species, Meganyctiphanes , North Atlantic krill, to visu...
Published in: | Journal of Plankton Research |
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Main Authors: | , |
Format: | Text |
Language: | English |
Published: |
Oxford University Press
2004
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Subjects: | |
Online Access: | http://plankt.oxfordjournals.org/cgi/content/short/26/11/1315 https://doi.org/10.1093/plankt/fbh122 |
Summary: | The act of swimming in formation by species such as Euphausia superba , Antarctic krill, is assumed to be regulated by a sensitivity to the characteristic and spatially elaborate flow field produced by this species of shrimp. We used a related species, Meganyctiphanes , North Atlantic krill, to visualize the flow field produced by tethered shrimps in an aquarium. In this situation, the propulsion jet flow some centimeters behind the shrimp is surrounded by a vortex ring of recoiling water motion from which, if the vortex is also produced by unrestrained swimming shrimp, a following shrimp hypothetically can draw forces of lift and propulsion to decrease energy expense in long-distance migration. Two antennular sensitivities to water vibration in frequency ranges 5–40 and 40–150 Hz were calibrated, and the activity of connected interneurons was traced into the abdominal pleopod-carrying segments. Water oscillation of 3–10 Hz frequency, applied to the antennules, was shown to entrain a closely synchronous pleopod beat in the stimulated specimens. |
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