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Preuss A, Büscher TH, Herzog I, Wohlsein P, Lehnert K, Gorb SN. Attachment performance of the ectoparasitic seal louse Echinophthirius horridus. Commun Biol 2024; 7:36. [PMID: 38182875 PMCID: PMC10770372 DOI: 10.1038/s42003-023-05722-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Accepted: 12/18/2023] [Indexed: 01/07/2024] Open
Abstract
Marine mammals host a great variety of parasites, which usually co-evolved in evolutionary arms races. However, little is known about the biology of marine mammal insect parasites, and even less about physical aspects of their life in such a challenging environment. One of 13 insect species that manage to endure long diving periods in the open sea is the seal louse, Echinophthirius horridus, parasitising true seals. Its survival depends on its specialised adaptations for enduring extreme conditions such as hypoxia, temperature changes, hydrostatic pressure, and strong drag forces during host dives. To maintain a grip on the seal fur, the louse's leg morphology is equipped with modified snap hook claws and soft pad-like structures that enhance friction. Through techniques including CLSM, SEM, and histological staining, we have examined the attachment system's detailed structure. Remarkably, the seal louse achieves exceptional attachment forces on seal fur, with safety factors (force per body weight) reaching 4500 in average measurements and up to 18000 in peak values, indicating superior attachment performance compared to other insect attachment systems. These findings underscore the louse's remarkable adaptations for life in a challenging marine environment, shedding light on the relationship between structure and function in extreme ecological niches.
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Affiliation(s)
- Anika Preuss
- Department of Functional Morphology and Biomechanics, Zoological Institute, Kiel University, Kiel, Germany.
| | - Thies H Büscher
- Department of Functional Morphology and Biomechanics, Zoological Institute, Kiel University, Kiel, Germany
| | - Insa Herzog
- Institute for Terrestrial and Aquatic Wildlife Research, University of Veterinary Medicine Hannover, Büsum, Germany
| | - Peter Wohlsein
- Department of Pathology, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Kristina Lehnert
- Institute for Terrestrial and Aquatic Wildlife Research, University of Veterinary Medicine Hannover, Büsum, Germany
| | - Stanislav N Gorb
- Department of Functional Morphology and Biomechanics, Zoological Institute, Kiel University, Kiel, Germany
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Ditsche P, Hoffmann F, Kaehlert S, Kesel A, Gorb S. Hydrofoil-like legs help stream mayfly larvae to stay on the ground. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2023; 209:325-336. [PMID: 36841919 PMCID: PMC10006037 DOI: 10.1007/s00359-023-01620-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Revised: 02/08/2023] [Accepted: 02/09/2023] [Indexed: 02/27/2023]
Abstract
Adaptations to flow have already been in the focus of early stream research, but till today morphological adaptations of stream insects are hardly understood. While most previous stream research focused on drag, the effects of lift on ground-living stream insects have been often overlooked. Stream mayfly larvae Ecdyonurus sp. graze on algae on top of the stones and therefore inhabit current exposed places in streams. They have a dorso-ventrally flattened body shape, which is known to reduce drag. However, this body shape enhances lift too, increasing the danger for the animal of getting detached from the substrate. Using microscopic techniques, 3D-printing, and drag and lift measurements in a wind tunnel, our experiments show that the widened femora of Ecdyonurus sp. can generate negative lift, contributing to counterbalance the (positive) lift of the overall body shape. The larvae can actively regulate the amount of lift by adjusting the femur's tilt or optimizing the distance to the ground. This shows that morphological adaptations of benthic stream insects can be very elaborate and can reach far beyond adaptations of the overall body shape. In the presented case, Ecdyonurus sp. takes advantage of the flow to overcome the flow's challenges.
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Affiliation(s)
- Petra Ditsche
- Department of Functional Morphology and Biomechanics, Zoological Institute, University of Kiel, 24098, Kiel, Germany
- Biomimetics-Innovation-Centre, City University of Applied Sciences, 28199, Bremen, Germany
- Friday Harbor Laboratories, University of Washington, Friday Harbor, WA, 98250, USA
- ClingTech Bionics UG, 53757, Sankt Augustin, Germany
| | - Florian Hoffmann
- Biomimetics-Innovation-Centre, City University of Applied Sciences, 28199, Bremen, Germany
| | - Sarah Kaehlert
- Department of Functional Morphology and Biomechanics, Zoological Institute, University of Kiel, 24098, Kiel, Germany
| | - Antonia Kesel
- Biomimetics-Innovation-Centre, City University of Applied Sciences, 28199, Bremen, Germany
| | - Stanislav Gorb
- Department of Functional Morphology and Biomechanics, Zoological Institute, University of Kiel, 24098, Kiel, Germany.
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Büscher TH, Gorb SN. Convergent Evolution of Adhesive Properties in Leaf Insect Eggs and Plant Seeds: Cross-Kingdom Bioinspiration. Biomimetics (Basel) 2022; 7:biomimetics7040173. [PMID: 36412700 PMCID: PMC9680409 DOI: 10.3390/biomimetics7040173] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2022] [Revised: 10/18/2022] [Accepted: 10/20/2022] [Indexed: 12/14/2022] Open
Abstract
Plants and animals are often used as a source for inspiration in biomimetic engineering. However, stronger engagement of biologists is often required in the field of biomimetics. The actual strength of using biological systems as a source of inspiration for human problem solving does not lie in a perfect copy of a single system but in the extraction of core principles from similarly functioning systems that have convergently solved the same problem in their evolution. Adhesive systems are an example of such convergent traits that independently evolved in different organisms. We herein compare two analogous adhesive systems, one from plants seeds and one from insect eggs, to test their properties and functional principles for differences and similarities in order to evaluate the input that can be potentially used for biomimetics. Although strikingly similar, the eggs of the leaf insect Phyllium philippinicum and the seeds of the ivy gourd Coccinia grandis make use of different surface structures for the generation of adhesion. Both employ a water-soluble glue that is spread on the surface via reinforcing fibrous surface structures, but the morphology of these structures is different. In addition to microscopic analysis of the two adhesive systems, we mechanically measured the actual adhesion generated by both systems to quantitatively compare their functional differences on various standardized substrates. We found that seeds can generate much stronger adhesion in some cases but overall provided less reliable adherence in comparison to eggs. Furthermore, eggs performed better regarding repetitive attachment. The similarities of these systems, and their differences resulting from their different purposes and different structural/chemical features, can be informative for engineers working on technical adhesive systems.
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Bergmann JB, Moatsou D, Steiner U, Wilts BD. Bio-inspired materials to control and minimise insect attachment. BIOINSPIRATION & BIOMIMETICS 2022; 17:051001. [PMID: 36099911 DOI: 10.1088/1748-3190/ac91b9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Accepted: 09/13/2022] [Indexed: 06/15/2023]
Abstract
More than three quarters of all animal species on Earth are insects, successfully inhabiting most ecosystems on the planet. Due to their opulence, insects provide the backbone of many biological processes, but also inflict adverse impacts on agricultural and stored products, buildings and human health. To countermeasure insect pests, the interactions of these animals with their surroundings have to be fully understood. This review focuses on the various forms of insect attachment, natural surfaces that have evolved to counter insect adhesion, and particularly features recently developed synthetic bio-inspired solutions. These bio-inspired solutions often enhance the variety of applicable mechanisms observed in nature and open paths for improved technological solutions that are needed in a changing global society.
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Affiliation(s)
- Johannes B Bergmann
- Adolphe Merkle Institute, University of Fribourg, Chemin des Verdiers 4, 1700 Fribourg, Switzerland
| | - Dafni Moatsou
- Institute of Organic Chemistry, Karlsruhe Institute for Technology, Fritz-Haber-Weg 6, 76131 Karlsruhe, Germany
| | - Ullrich Steiner
- Adolphe Merkle Institute, University of Fribourg, Chemin des Verdiers 4, 1700 Fribourg, Switzerland
| | - Bodo D Wilts
- Adolphe Merkle Institute, University of Fribourg, Chemin des Verdiers 4, 1700 Fribourg, Switzerland
- Chemistry and Physics of Materials, University of Salzburg, Jakob-Haringer-Str. 2a, 5020 Salzburg, Austria
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Wang Y, Hensel R, Arzt E. Attachment of bioinspired microfibrils in fluids: transition from a hydrodynamic to hydrostatic mechanism. J R Soc Interface 2022; 19:20220050. [PMID: 35382580 PMCID: PMC8984370 DOI: 10.1098/rsif.2022.0050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Reversible and switchable adhesion of elastomeric microstructures has attracted significant interest in the development of grippers for object manipulation. Their applications, however, have often been limited to dry conditions and adhesion of such deformable microfibrils in the fluid environment is less understood. In the present study, we performed adhesion tests in silicone oil using single cylindrical microfibrils of a flat-punch shape with a radius of 80 µm. Stiff fibrils were created using three-dimensional printing of an elastomeric resin with an elastic modulus of 500 MPa, and soft fibrils, with a modulus of 3.3 MPa, were moulded in polyurethane. Our results suggest that adhesion is dominated by hydrodynamic forces, which can be maximized by stiff materials and high retraction velocities, in line with theoretical predictions. The maximum pull-off stress of stiff cylindrical fibrils is 0.6 MPa, limited by cavitation and viscous fingering, occurring at retraction velocities greater than 2 µm s-1. Next, we add a mushroom cap to the microfibrils, which, in the case of the softer material, deforms upon retraction and leads to a transition to a hydrostatic suction regime with higher pull-off stresses ranging from 0.7 to 0.9 MPa. The effects of elastic modulus, fibril size and viscosity for underwater applications are illustrated in a mechanism map to provide guidance for design optimization.
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Affiliation(s)
- Yue Wang
- INM - Leibniz Institute for New Materials, Campus D2 2, 66123 Saarbrücken, Germany
| | - René Hensel
- INM - Leibniz Institute for New Materials, Campus D2 2, 66123 Saarbrücken, Germany
| | - Eduard Arzt
- INM - Leibniz Institute for New Materials, Campus D2 2, 66123 Saarbrücken, Germany.,Department of Materials Science and Engineering, Saarland University, Campus D2 2, 66123 Saarbrücken, Germany
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