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The morphology and adhesion mechanism of Octopus vulgaris suckers.

Tramacere F, Beccai L, Kuba M, Gozzi A, Bifone A, Mazzolai B - PLoS ONE (2013)

Bottom Line: We use three different techniques (MRI, ultrasonography, and histology) and a 3D reconstruction approach to contribute knowledge on both morphology and functionality of the sucker structure in O. vulgaris.The results of our investigation are two-fold.In particular, in O. vulgaris the acetabular chamber, that is a hollow spherical cavity in other octopuses, shows an ellipsoidal cavity which roof has an important protuberance with surface roughness.

View Article: PubMed Central - PubMed

Affiliation: Center for Micro-BioRobotics, Istituto Italiano di Tecnologia, Pontedera, Italy. francesca.tramacere@iit.it

ABSTRACT
The octopus sucker represents a fascinating natural system performing adhesion on different terrains and substrates. Octopuses use suckers to anchor the body to the substrate or to grasp, investigate and manipulate objects, just to mention a few of their functions. Our study focuses on the morphology and adhesion mechanism of suckers in Octopus vulgaris. We use three different techniques (MRI, ultrasonography, and histology) and a 3D reconstruction approach to contribute knowledge on both morphology and functionality of the sucker structure in O. vulgaris. The results of our investigation are two-fold. First, we observe some morphological differences with respect to the octopus species previously studied (i.e., Octopus joubini, Octopus maya, Octopus bimaculoides/bimaculatus and Eledone cirrosa). In particular, in O. vulgaris the acetabular chamber, that is a hollow spherical cavity in other octopuses, shows an ellipsoidal cavity which roof has an important protuberance with surface roughness. Second, based on our findings, we propose a hypothesis on the sucker adhesion mechanism in O. vulgaris. We hypothesize that the process of continuous adhesion is achieved by sealing the orifice between acetabulum and infundibulum portions via the acetabular protuberance. We suggest this to take place while the infundibular part achieves a completely flat shape; and, by sustaining adhesion through preservation of sucker configuration. In vivo ultrasonographic recordings support our proposed adhesion model by showing the sucker in action. Such an underlying physical mechanism offers innovative potential cues for developing bioinspired artificial adhesion systems. Furthermore, we think that it could possibly represent a useful approach in order to investigate any potential difference in the ecology and in the performance of adhesion by different species.

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Octopus vulgaris sucker during adhesion process.A) Ultrasonography of middle transverse section of sucker attached to the ultrasonographic probe. B) Schematic of A: a, acetabulum; in, infundibulum; w, water; p, ultrasonographic probe. The acetabular protuberance is in contact with the upper part of the side walls of the orifice. The scale bar equals 1 cm.
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pone-0065074-g006: Octopus vulgaris sucker during adhesion process.A) Ultrasonography of middle transverse section of sucker attached to the ultrasonographic probe. B) Schematic of A: a, acetabulum; in, infundibulum; w, water; p, ultrasonographic probe. The acetabular protuberance is in contact with the upper part of the side walls of the orifice. The scale bar equals 1 cm.

Mentions: We observed that when suckers come in contact with the substrate the infundibular part changes its shape, from a conical shape to a completely flat shape, whereas the acetabular part remains almost unchanged. It is worth noting that during the adhesion configuration, the acetabular roof protuberance is in contact with the upper part of the side walls of the orifice (Figure 6 and Video S2). This way, the orifice closure forms two water compartments in the sucker corresponding to: the torus of water that is created in the acetabular cavity around the protuberance itself; and, the volume of water created between the lower part of the acetabular protuberance and the adhesion substrate.


The morphology and adhesion mechanism of Octopus vulgaris suckers.

Tramacere F, Beccai L, Kuba M, Gozzi A, Bifone A, Mazzolai B - PLoS ONE (2013)

Octopus vulgaris sucker during adhesion process.A) Ultrasonography of middle transverse section of sucker attached to the ultrasonographic probe. B) Schematic of A: a, acetabulum; in, infundibulum; w, water; p, ultrasonographic probe. The acetabular protuberance is in contact with the upper part of the side walls of the orifice. The scale bar equals 1 cm.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3672162&req=5

pone-0065074-g006: Octopus vulgaris sucker during adhesion process.A) Ultrasonography of middle transverse section of sucker attached to the ultrasonographic probe. B) Schematic of A: a, acetabulum; in, infundibulum; w, water; p, ultrasonographic probe. The acetabular protuberance is in contact with the upper part of the side walls of the orifice. The scale bar equals 1 cm.
Mentions: We observed that when suckers come in contact with the substrate the infundibular part changes its shape, from a conical shape to a completely flat shape, whereas the acetabular part remains almost unchanged. It is worth noting that during the adhesion configuration, the acetabular roof protuberance is in contact with the upper part of the side walls of the orifice (Figure 6 and Video S2). This way, the orifice closure forms two water compartments in the sucker corresponding to: the torus of water that is created in the acetabular cavity around the protuberance itself; and, the volume of water created between the lower part of the acetabular protuberance and the adhesion substrate.

Bottom Line: We use three different techniques (MRI, ultrasonography, and histology) and a 3D reconstruction approach to contribute knowledge on both morphology and functionality of the sucker structure in O. vulgaris.The results of our investigation are two-fold.In particular, in O. vulgaris the acetabular chamber, that is a hollow spherical cavity in other octopuses, shows an ellipsoidal cavity which roof has an important protuberance with surface roughness.

View Article: PubMed Central - PubMed

Affiliation: Center for Micro-BioRobotics, Istituto Italiano di Tecnologia, Pontedera, Italy. francesca.tramacere@iit.it

ABSTRACT
The octopus sucker represents a fascinating natural system performing adhesion on different terrains and substrates. Octopuses use suckers to anchor the body to the substrate or to grasp, investigate and manipulate objects, just to mention a few of their functions. Our study focuses on the morphology and adhesion mechanism of suckers in Octopus vulgaris. We use three different techniques (MRI, ultrasonography, and histology) and a 3D reconstruction approach to contribute knowledge on both morphology and functionality of the sucker structure in O. vulgaris. The results of our investigation are two-fold. First, we observe some morphological differences with respect to the octopus species previously studied (i.e., Octopus joubini, Octopus maya, Octopus bimaculoides/bimaculatus and Eledone cirrosa). In particular, in O. vulgaris the acetabular chamber, that is a hollow spherical cavity in other octopuses, shows an ellipsoidal cavity which roof has an important protuberance with surface roughness. Second, based on our findings, we propose a hypothesis on the sucker adhesion mechanism in O. vulgaris. We hypothesize that the process of continuous adhesion is achieved by sealing the orifice between acetabulum and infundibulum portions via the acetabular protuberance. We suggest this to take place while the infundibular part achieves a completely flat shape; and, by sustaining adhesion through preservation of sucker configuration. In vivo ultrasonographic recordings support our proposed adhesion model by showing the sucker in action. Such an underlying physical mechanism offers innovative potential cues for developing bioinspired artificial adhesion systems. Furthermore, we think that it could possibly represent a useful approach in order to investigate any potential difference in the ecology and in the performance of adhesion by different species.

Show MeSH
Related in: MedlinePlus