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Cited by 60Cephalopods and Marine BiologySoft Robotics and ApplicationsMarine Invertebrate Physiology and Ecology

Octopus Arms Exhibit Exceptional Flexibility

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Kennedy, E. B. Lane, Buresch, Kendra C., Boinapally, Preethi, Hanlon, Roger T.·2020·Scientific Reports
DOI 10.1038/s41598-020-77873-7PMC PMC7704652
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Abstract

The octopus arm is often referred to as one of the most flexible limbs in nature, yet this assumption requires detailed inspection given that this has not been measured comprehensively for all portions of each arm. We investigated the diversity of arm deformations in Octopus bimaculoides with a frame-by-frame observational analysis of laboratory video footage in which animals were challenged with different tasks. Diverse movements in these hydrostatic arms are produced by some combination of four basic deformations: bending (orally, aborally; inward, outward), torsion (clockwise, counter-clockwise), elongation, and shortening. More than 16,500 arm deformations were observed in 120 min of video. Results showed that all eight arms were capable of all four types of deformation along their lengths and in all directions. Arms function primarily to bring the sucker-lined oral surface in contact with target surfaces. Bending was the most common deformation observed, although the proximal third of the arms performed relatively less bending and more shortening and elongation as compared with other arm regions. These findings demonstrate the exceptional flexibility of the octopus arm and provide a basis for investigating motor control of the entire arm, which may aid the future development of soft robotics.

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  • The interplay of the three muscle groups and the lack of inherently rigid structure equips the arm with its remarkable flexibility.

    “The interplay of the three muscle groups and the lack of inherently rigid structure equips the arm with its remarkable flexibility (Kier and Smith, 1985; Kier and Stella, 2007; Kennedy et al., 2020).”

    From Lessons for Robotics From the Control Architecture of the Octopus (2022) · cites this paper as Kennedy et al., 2020

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Research works printed but not linked: 2

  1. [18]Jereb, P., Roper, C. F. E., Norman, M. D. & Finn, J. K. Cephalopods of the world: An annotated and illustrated catalogue of cephalopod species known to date. Volume 3: Octopods and vampire squids. in FAO Species Cat. Fish. Purp. No. 4, Vol. 3, 1–370 (2016).
  2. [26]Boyle, P. R. Neural control of cephalopod behavior. in The Mollusca, Vol. 9. Neurobiology and Behavior (ed. Willows, A. O. D.) 1–99 10.1016/B978-0-12-751409-3.50006-11 (Elsevier, 1986). · DOI

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Authors
Kennedy, E. B. L., Buresch, K. C., Boinapally, P., & Hanlon, R. T.
Affiliations
  • Marine Biological Laboratory (US)
  • Northeastern University (US)
Corresponding author
  • Kennedy, E. B. Lane
  • Hanlon, Roger T.
ORCID
Venue
Scientific Reports
Publisher
Springer Science and Business Media LLC
Published
2020-11-30
Volume
10
Issue
1
Pages
20872-20872
ISSN
2045-2322 (ISSN-L)
DOI
10.1038/s41598-020-77873-7
PMC
PMC7704652
OpenAlex
W3108006976
Cited by
60
References
45
Citations by year
2026: 9 · 2025: 12 · 2024: 9 · 2023: 18 · 2022: 7 · 2021: 5
FWCI
5.62
Type
journal article
Language
en
Open access
Licence
Locations
  • Scientific Reports (publishedVersion, cc-by)
  • PubMed Central (publishedVersion, cc-by)
  • PubMed (publishedVersion)
  • Open Access Server of the Woods Hole Scientific Community (Woods Hole Scientific Community) (submittedVersion, cc-by)
Funders
Office of Naval Research (N00014-19-1-2445)
Topics
  • Life Sciences › Agricultural and Biological Sciences › Ecology, Evolution, Behavior and Systematics › Cephalopods and Marine Biology
  • Physical Sciences › Engineering › Biomedical Engineering › Soft Robotics and Applications
  • Physical Sciences › Earth and Planetary Sciences › Paleontology › Marine Invertebrate Physiology and Ecology
Keywords
octopus arm, Octopus bimaculoides, bending, torsion, elongation, shortening, suckers, soft robotics, motor control, cephalopod locomotion
MeSH terms
Animals, Computer Simulation, Extremities, Models, Biological, Movement, Robotics, Octopodiformes

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