Parts is Parts ...


Staff member
Moderator (Staff)
Sep 4, 2006
Cape Coral, FL
A collection of articles describing cephalopod body parts and functions

The Structure and Adhesive Mechanism of Octopus Suckers 2002 WILLIAM M. KIER*,2 AND ANDREW M. SMITH†
*Department of Biology, CB# 3280 Coker Hall, University of North Carolina, Chapel Hill, North Carolina 27599-3280 †Department of Biology, CNS Room 155, Ithaca College, Ithaca, New York 14850

One mucktopus found:
This one looks like a great read! The W-shaped pupil in cuttlefish (Sepia officinalis): functions for improving horizontal vision Lydia M. Mäthger, Roger T. Hanlon, Jonas Håkansson, Dan-Eric Nilsson - March 2013

Additional Body Part threads/photos
Cephalopod Beaks in 3D

Giant Blue ring hectocotylus (photo)

Ligula (photo)

How to identify a squid from its tentacle

The Journal of Experimental Biology search cephalopod
Awesome thread, my reference manager will visit this often. I will post the links to the following when I have more time but for now here are titles I recommend, primarily for octo arm and suckers:

Barber, V. C. (2010). The sense organs of Nautilus. Nautilus, 223-230.

Budelmann, B., Schipp, R. & Boletzky, S.v. (1997). Cephalopoda. Microscopic Anatomy of Invertebrates, 6(A), 119-414.

Calisti, M., Giorelli, M., Levy, G., Mazzolai, B., Hochner, B., Laschi, C., et al. (2011). An octopus-bioinspired solution to movement and manipulation for soft robots. Bioinspiration & Biomimetics, 6, 036-042.

Cianchetti, M., Arienti, A., Follador, M., Mazzolai, B., Dario, P., & Laschi, C. (2010). Design concept and validation of a robotic arm inspired by the octopus. Materials Science and Engineering: C, 31(6), 1230-1239.

Cyran, N., Klinger, L., Scott, R., Griffiths, C., Schwaha, T., Zheden, V., et al. (2010). Characterization of the Adhesive Systems in Cephalopods. Biological Adhesive Systems, 53-86.

Girod, P. (1884). Recherches sur la peau des céphalopodes. La ventouse. Arch. Zool. Exp. Gen, 2, 379-401.

Grasso, F. W. (2008). Octopus sucker-arm coordination in grasping and manipulation. American Malacological Bulletin, 24(1), 13-23.

Graziadei, P. (1962). Receptors in the suckers of Octopus. Nature, 195, 57-59.

Graziadei, P. (1964). Electron microscopy of some primary receptors in the sucker of Octopus vulgaris. Cell and Tissue Research, 64(4), 510-522.

Graziadei, P. (1965). Muscle receptors in cephalopods. Proceedings of the Royal Society of London. Series B. Biological Sciences, 161(984), 392.

Graziadei, P., & Gagne, H. (1976). Sensory innervation in the rim of the octopus sucker. Journal of Morphology, 150(3), 639-679.

Gutfreund, Y. (2000). The intricacies of flexible arms. Science Spectra(19), 28-37. can't find this anywhere anymore

Gutfreund, Y., Flash, T., Fiorito, G., & Hochner, B. (1998). Patterns of arm muscle activation involved in octopus reaching movements. The Journal of neuroscience, 18(15), 5976-5987.

Gutfreund, Y., Flash, T., Yarom, Y., Fiorito, G., Segev, I., & Hochner, B. (1996). Organization of octopus arm movements: a model system for studying the control of flexible arms. The Journal of neuroscience, 16(22), 7297-7307.

Gutnick, T., Byrne, R. A., Hochner, B., & Kuba, M. (2011). Octopus vulgaris Uses Visual Information to Determine the Location of Its Arm. Current Biology, 21(6), 460-462.

Kier, W., & Thompson, J. (2003). Muscle arrangement, function and specialization in recent coleoids. Berliner Paläobiologische Abhandlungen, 3, 141-162.

Kier, W. M. (1982). The functional morphology of the musculature of squid (Loliginidae) arms and tentacles. Journal of Morphology, 172(2), 179-192.

Kier, W. M., & Smith, A. M. (1990). The morphology and mechanics of octopus suckers. The Biological Bulletin, 178(2), 126.

Kier, W. M., & Smith, K. K. (1985). Tongues, tentacles and trunks: the biomechanics of movement in muscular hydrostats. Zoological Journal of the Linnean Society, 83(4), 307-324.

Kier, W. M., & Stella, M. P. (2007). The arrangement and function of octopus arm musculature and connective tissue. Journal of Morphology, 268(10), 831-843.

Laschi, C., Mazzolai, B., Mattoli, V., Cianchetti, M., & Dario, P. (2009). Design of a biomimetic robotic octopus arm. Bioinspiration & Biomimetics, 4, 015006.

Mather, J. A. (1998). How do octopuses use their arms? Journal of Comparative Psychology, 112(3), 306.

Matzner, H., Gutfreund, Y., & Hochner, B. (2000). Neuromuscular system of the flexible arm of the octopus: physiological characterization. Journal of Neurophysiology, 83(3), 1315-1328.

McMahan, W., & Walker, I. D. (2009). Octopus-inspired grasp-synergies for continuum manipulators.

Niven, J. E. (2011). Invertebrate Neurobiology: Visual Direction of Arm Movements in an Octopus. Current Biology, 21(6), R217-R218.

Nixon, M., & Dilly, P. (1977). Sucker surfaces and prey capture. Paper presented at the Symp. Zool. Soc. , London.

Packard, A. (1988). Visual tactics and evolutionary strategies. Cephalopods Present and Past, 89–103.

Rowell, C. (1963). Excitatory and inhibitory pathways in the arm of Octopus. Journal of experimental biology, 40(2), 257-270.

Rowell, C. (1966). Activity of interneurones in the arm of Octopus in response to tactile stimulation. Journal of experimental biology, 44(3), 589-605.

Smith, A. (1996). Cephalopod sucker design and the physical limits to negative pressure. Journal of experimental biology, 199(4), 949-958.

Smith, A. M. (1991). Negative pressure generated by octopus suckers: a study of the tensile strength of water in nature. Journal of experimental biology, 157(1), 257-271.

Sumbre, G., Gutfreund, Y., Fiorito, G., Flash, T., & Hochner, B. (2001). Control of octopus arm extension by a peripheral motor program. Science, 293(5536), 1845-1848.

Walker, I. D., Dawson, D. M., Flash, T., Grasso, F., Hanlon, R., Hochner, B., et al. (2005). Continuum robot arms inspired by cephalopods. Paper presented at the Proceedings of the 2005 SPIE Conference on Unmanned Ground Vehicle Technology IV, Orlando, Florida, USA.

Wells, M. (1963). Taste by touch: some experiments with Octopus. Journal of experimental biology, 40(1), 187-193.

Wells, M. J. (1978). Octopus. Physiology and Behaviour of an Advanced Invertebrate. Chapman and Hall, London.

Woolley, B., & Stanley, K. (2011). Evolving a single scalable controller for an octopus arm with a variable number of segments. Parallel Problem Solving from Nature–PPSN XI, 270-279.


Young, J. (1963). The number and sizes of nerve cells in Octopus. Paper presented at the Proceedings of the Zoological Society of London, London, England.

Young, J. Z., & Boycott, B. B. (1971). The anatomy of the nervous system of Octopus vulgaris: Clarendon Press Oxford.

Zelman, I., Galun, M., Akselrod-Ballin, A., Yekutieli, Y., Hochner, B., & Flash, T. (2009). Nearly automatic motion capture system for tracking octopus arm movements in 3D space. Journal of neuroscience methods, 182(1), 97-109.
Dorsal Mantle White Spots

A question I have asked many time but have never gotten an answer to is,

"What are the two white oval spots about mid-way along the length of the mantle?"

After an ID comment I started to research the spots because I had seen them on an obviously different animal and found that they are present on most species. I have seen them on several I've kept and found them on virtually 90% of the photos in Norman's Cephalopods A World Guide (sometimes you have to REALLY look but you will see them on most octos with multiple photos). I finally cornered Muctopus on the question and got an answer (sort of :biggrin2:)

Ahhh the 'Dorsal Mantle White Spots'...Lots of octopuses have them. They're leucophore-rich fields on the skin that to not move. Various authors (I think Packard, Sanders, Hochberg, and Hanlon) have mentioned the DMWS and/or frontal white spots on the arm crown may distract a predator, though they do draw attention to an important part of the body (the bit holding all the guts). It's possible these fields also display polarized signals that we can't see.
Wouldn't it be better to have a separate, gene-focused thread?

This paper (free) talks about genetic differences between certain octopus species, particularly with respect to the one they're describing, O. insularis. It was very similar in appearance to the larger O. vulgaris, but turns out to be much further away in mitochondrial genes than expected:

The paper describes both the dorsal mantle white spots and arm crown spots in that species as distinct structures in common with O. vulgaris, but does not give much in the way of details.

The pupillary response of cephalopods 2004 R. H. Douglas1,R. Williamson, H.-J. Wagner

This paper provides the first detailed description of the time courses of light-evoked pupillary constriction for two species of cephalopods, Sepia officinalis (a cuttlefish) and Eledone cirrhosa (an octopus). The responses are much faster than hitherto reported, full contraction in Sepia taking less than 1 s, indicating it is among the most rapid pupillary responses in the animal kingdom. We also describe the dependence of the degree of pupil constriction on the level of ambient illumination and show considerable variability between animals. Furthermore, both Sepia and Eledone lack a consensual light-evoked pupil response. Pupil dilation following darkness in Sepia is shown to be very variable, often occurring within a second but at other times taking considerably longer. This may be the result of extensive light-independent variations in pupil diameter in low levels of illumination

A Unique Advantage for Giant Eyes in Giant Squid 2012 Duke University (Full pdf linked)
Dan-Eric Nilsson, Eric J. Warrant,So¨nke Johnsen, Roger Hanlon, Nadav Shashar

Giant and colossal deep-sea squid (Architeuthis and Mesonychoteuthis) have the largest eyes in the animal kingdom [1, 2], but there is no explanation for why they would need eyes that are nearly three times the diameter of those of any other extant animal. Here we develop a theory for visual detection in pelagic habitats, which predicts that such giant eyes are unlikely to evolve for detecting mates or prey at long distance but are instead uniquely suited for detecting very
large predators, such as sperm whales. We also provide photographic documentation of an eyeball of about 27 cm with a 9 cm pupil in a giant squid, and we predict that, below
600 m depth, it would allow detection of sperm whales at distances exceeding 120 m. With this long range of vision, giant squid get an early warning of approaching sperm whales. Because the sonar range of sperm whales exceeds 120 m [3–5], we hypothesize that a well-prepared and powerful evasive response to hunting sperm whales may have driven the evolution of huge dimensions in both eyes and bodies of giant and colossal squid. Our theory also provides
insights into the vision of Mesozoic ichthyosaurs with unusually large eyes.
Last edited:
ARMS - reflexes

Preliminary in vitro functional evidence for reflex responses to noxious stimuli in the arms of Octopus vulgaris
Theresa Hague,Michaela Florini,Paul L.R. Andrews September 2013
Full text available.

The arms of Octopus vulgaris perform a number of functions (e.g. prey capture, exploration) putting them at risk of damage. Nociceptive reflexes provide one defence and as there is a paucity of evidence for such reflexes in cephalopods we have investigated this in isolated arms. The arms were removed immediately post mortem from O. vulgaris, suspended vertically or mounted horizontally and the responses to a pinch of the distal arm and application of acetic acid (0.1%–5.0%) or tap water to the tip recorded (video). Isolated arms rapidly (~ 1 s) withdrew in response to a pinch, tap water and acetic acid (threshold 1%) applied to the tip region. A “quasi-joint” formed in the proximal arm during the withdrawal response in horizontally mounted preparations. No response was evoked by sea water or gentle compression. Withdrawal responses were abolished by axial nerve cord section proximal to the site of stimulation.
The results demonstrate that the arms are capable of reflex withdrawal to a “noxious” stimulus without reference to the brain. Neurophysiological studies in a more technically refined preparation are required to define the temporal characteristics of the reflex and to characterise the putative nociceptors (or other receptor types) and to determine if information from them reaches the brain.
Beak identification of four dominant octopus species in the East China Sea based on traditional measurements and geometric morphometrics
Zhou Fang, Jiangtao Fan, Xinjun Chen, Yangyang Chen
Octopus is the most abundant genus in the family Octopodidae and accounts for more than half of the total cephalopod landing in neritic fisheries. A taxonomic problem still exists due to synonymous scientific names and limited genetic information. The cephalopod beak is a stable structure that allows an effective solution to the problem of the species and stock identification. Beak shape variation has been more widely considered than beak measurements in recent years. In this study, with the beak as the experimental material, we combined geometric morphometrics (GM) with machine learning methods and compared the discrimination results obtained by traditional and GM methods in four Chinese neritic octopus species (Amphioctopus fangsiao, Amphioctopus ovulum, Octopus minorand Octopus sinensis). According to our analyses, Octopus sinensis has the larger beak size [both upper beak (UB) and lower beak (LB)] than other species. The results of ANOVA showed that all beak measurements differed significantly among the four species. Significant differences in both UB and LB shapes among four species were identified in MANOVA analysis based on the GM method. The results of GM-based discriminant analysis were better than those of traditional measurements, and machine learning methods also showed the higher correct classification rates than linear discriminant analysis. GM is a useful method to reconstruct the shape cephalopod beak and can also effectively distinguish different species. We should improve classification accuracy with machine learning methods for determining species structure in the future.

Shop Amazon

Shop Amazon
Shop Amazon; support TONMO!
Shop Amazon
We are a participant in the Amazon Services LLC Associates Program, an affiliate program designed to provide a means for us to earn fees by linking to Amazon and affiliated sites.