Swimming Kinematics of Cyprids of the Barnacle Balanus glandula
| Autor: | Richard B. Emlet, Eleanor I. Lamont |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
0106 biological sciences
0301 basic medicine Plant Science Kinematics Balanus glandula 01 natural sciences Copepoda 03 medical and health sciences Barnacle Animals Paddle Swimming Appendage biology 010604 marine biology & hydrobiology Thoracica Seta Anatomy biology.organism_classification Crustacean Biomechanical Phenomena 030104 developmental biology Drag Larva Animal Science and Zoology human activities |
| Zdroj: | Integrative and Comparative Biology. 61:1567-1578 |
| ISSN: | 1557-7023 1540-7063 |
| Popis: | Synopsis Larvae of barnacles typically pass through naupliar and cyprid planktonic stages before settlement and metamorphosis. As the final larval stage, cyprids swim much faster than nauplii and in turbulent fluid environments with high shears as they seek habitat. Cyprids swim with six pairs of reciprocating thoracic appendages and use two anterior antennules during settlement. Our understanding of how thoracic appendages generate movement is limited due to short stroke intervals (∼5 ms) that impede observations of the shape and trajectory of appendages. Here, we used high-speed videography to observe both free-swimming and tethered cyprids of the intertidal acorn barnacle Balanus glandula to produce a comprehensive description of thoracic appendage swimming kinematics. Cyprids used a drag-based method of swimming: their six pairs of thoracic appendages moved through metachronal power strokes and synchronous recovery strokes similar to the thoracopod motions in calanoid copepods during escape swimming. During the power stroke, plumose setae on each appendage pair spread laterally into a high surface area and high drag paddle composed of a meshwork of fused setules. This interconnected setal array collapsed into a low surface area and low drag shape during the recovery stroke. These effective swimming appendages allowed cyprids to move upward at an average speed of 1.4 cm/s (∼25 body lengths/s) with an average beat frequency of 16 beats/s, and reach an instantaneous velocity of up to 6 cm/s. Beat frequency of the thoracic appendages was significantly associated with speed, with higher beat frequencies indicating faster swimming speed. At their average speed, cyprids moved at the intermediate Reynolds number of ∼10, in which both viscous and inertial forces affected movement. Cyprids could alter swimming direction by sweeping the posterior-most appendage pair to one side and beating the remaining thoracic appendages synchronously through the power stroke with greater motion on the outside of their turn. These results greatly enhance our understanding both of cyprid motility and how small planktonic organisms can use swimming appendages with fused setule arrays to reach high swimming speeds and affect directional changes. |
| Databáze: | OpenAIRE |
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