Neil, TR orcid.org/0000-0001-7536-3373 and Askew, GN orcid.org/0000-0003-1010-4439 (2018) Jet-paddling jellies: swimming performance in the Rhizostomeae jellyfish Catostylus mosaicus (Quoy and Gaimard, 1824). The Journal of Experimental Biology, 221 (24). jeb191148. ISSN 0022-0949
Abstract
Jellyfish are a successful and diverse class of animals that swim via jet propulsion, with swimming performance and propulsive efficiency being related to the animal's feeding ecology and body morphology. The Rhizostomeae jellyfish lack tentacles but possess four oral lobes and eight trailing arms at the centre of their bell, giving them a body morphology quite unlike that of other free-swimming medusae. The implications of this body morphology on the mechanisms by which thrust is produced are unknown. Here we determined the wake structure and propulsive efficiency in the blue-blubber jellyfish Catostylus mosaicus; order Rhizostomeae). The animal is propelled during both bell contraction and bell relaxation by different thrust generating mechanisms. During bell contraction, a jet of fluid is expelled from the subumbrellar cavity, which results from the interaction between the counter-rotating stopping (from the preceding contraction cycle) and starting vortices, creating a vortex superstructure and propulsion. This species is also able to utilize passive energy recapture, that increases the animal's swimming velocity towards the end of the bell expansion phase when the bell diameter is constant. The thrust produced during this phase is the result of the flexible bell margin manoeuvring the stopping vortex into the subumbrellar cavity during bell relaxation, enhancing its circulation, and creating a region of high pressure on the inner surface of the bell and, consequently, thrust. These mechanisms of thrust generation result in C. mosaicus having a relatively high propulsive efficiency compared to other swimmers, indicating that economical locomotion could be a contributing factor in the ecological success of these medusan swimmers.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2018. Published by The Company of Biologists Ltd. This is an author produced version of a paper published in Journal of Experimental Biology. Uploaded in accordance with the publisher's self-archiving policy. |
Keywords: | medusa, fluid dynamics, wake structure, vorticity, Cnidaria, Scyphozoa |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Biological Sciences (Leeds) > School of Biomedical Sciences (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 04 Dec 2018 14:45 |
Last Modified: | 17 Dec 2024 11:39 |
Status: | Published |
Publisher: | Company of Biologists |
Identification Number: | 10.1242/jeb.191148 |
Related URLs: | |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:139522 |