The ectoparasitic seal louse, Echinophthirius horridus, relies on a sealed tracheal system and spiracle closing apparatus for underwater respiration
Abstract Marine mammals host a diverse array of parasites engaged in a continuous evolutionary arms race. However, our understanding of the biology of parasitic insects associated with marine mammals, particularly their adaptations to challenging marine environments, remains limited. The seal louse,...
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Nature Portfolio
2025-06-01
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| Series: | Communications Biology |
| Online Access: | https://doi.org/10.1038/s42003-025-08285-4 |
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| author | Anika Preuss Thomas Schwaha Alexander Kovalev David Ebmer Insa Herzog Kristina Lehnert Corvin Grass Freya Sandberg Elias Hamann Marcus Zuber Thomas van de Kamp Stanislav N. Gorb |
| author_facet | Anika Preuss Thomas Schwaha Alexander Kovalev David Ebmer Insa Herzog Kristina Lehnert Corvin Grass Freya Sandberg Elias Hamann Marcus Zuber Thomas van de Kamp Stanislav N. Gorb |
| author_sort | Anika Preuss |
| collection | DOAJ |
| description | Abstract Marine mammals host a diverse array of parasites engaged in a continuous evolutionary arms race. However, our understanding of the biology of parasitic insects associated with marine mammals, particularly their adaptations to challenging marine environments, remains limited. The seal louse, Echinophthirius horridus, which infests true seals, is one of thirteen insect species capable of enduring prolonged dives in open seas. This ectoparasite has evolved several adaptations to withstand extreme conditions, such as low oxygen levels (hypoxia), temperature fluctuations, hydrostatic pressure, and strong drag forces during dives. To prevent drowning during their host’s 20–35 min dives, seal lice have developed specialized respiratory mechanisms that allow them to survive in oxygen-poor waters and at depths up to 600 m. Advanced imaging techniques, including CLSM, SEM, synchrotron X-ray microtomography, and histological sectioning and 3D-reconstruction, have revealed a specialized spiracle closing apparatus for storing oxygen in their tracheal system. Furthermore, our buoyancy experiments showed that the lice consume oxygen under water and, with morphological data, provide what is to our knowledge the first direct evidence against plastron presence. These findings enhance our understanding of the physical adaptations of lice and their survival in extreme ecological conditions, contributing to broader ecological and evolutionary theories. |
| format | Article |
| id | doaj-art-55ce93bba8c042f2a1ca121af5dfcbe2 |
| institution | DOAJ |
| issn | 2399-3642 |
| language | English |
| publishDate | 2025-06-01 |
| publisher | Nature Portfolio |
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| spelling | doaj-art-55ce93bba8c042f2a1ca121af5dfcbe22025-08-20T03:10:35ZengNature PortfolioCommunications Biology2399-36422025-06-018111310.1038/s42003-025-08285-4The ectoparasitic seal louse, Echinophthirius horridus, relies on a sealed tracheal system and spiracle closing apparatus for underwater respirationAnika Preuss0Thomas Schwaha1Alexander Kovalev2David Ebmer3Insa Herzog4Kristina Lehnert5Corvin Grass6Freya Sandberg7Elias Hamann8Marcus Zuber9Thomas van de Kamp10Stanislav N. Gorb11Department of Functional Morphology and Biomechanics, Zoological Institute, Kiel UniversityDepartment of Evolutionary Biology, University of ViennaDepartment of Functional Morphology and Biomechanics, Zoological Institute, Kiel UniversityVienna ZooInstitute for Terrestrial and Aquatic Wildlife Research, University of Veterinary Medicine HannoverInstitute for Terrestrial and Aquatic Wildlife Research, University of Veterinary Medicine HannoverDepartment of Functional Morphology and Biomechanics, Zoological Institute, Kiel UniversityDepartment of Functional Morphology and Biomechanics, Zoological Institute, Kiel UniversityKarlsruhe Institute of Technology, Institute for Photon Science and Synchrotron RadiationKarlsruhe Institute of Technology, Institute for Photon Science and Synchrotron RadiationKarlsruhe Institute of Technology, Institute for Photon Science and Synchrotron RadiationDepartment of Functional Morphology and Biomechanics, Zoological Institute, Kiel UniversityAbstract Marine mammals host a diverse array of parasites engaged in a continuous evolutionary arms race. However, our understanding of the biology of parasitic insects associated with marine mammals, particularly their adaptations to challenging marine environments, remains limited. The seal louse, Echinophthirius horridus, which infests true seals, is one of thirteen insect species capable of enduring prolonged dives in open seas. This ectoparasite has evolved several adaptations to withstand extreme conditions, such as low oxygen levels (hypoxia), temperature fluctuations, hydrostatic pressure, and strong drag forces during dives. To prevent drowning during their host’s 20–35 min dives, seal lice have developed specialized respiratory mechanisms that allow them to survive in oxygen-poor waters and at depths up to 600 m. Advanced imaging techniques, including CLSM, SEM, synchrotron X-ray microtomography, and histological sectioning and 3D-reconstruction, have revealed a specialized spiracle closing apparatus for storing oxygen in their tracheal system. Furthermore, our buoyancy experiments showed that the lice consume oxygen under water and, with morphological data, provide what is to our knowledge the first direct evidence against plastron presence. These findings enhance our understanding of the physical adaptations of lice and their survival in extreme ecological conditions, contributing to broader ecological and evolutionary theories.https://doi.org/10.1038/s42003-025-08285-4 |
| spellingShingle | Anika Preuss Thomas Schwaha Alexander Kovalev David Ebmer Insa Herzog Kristina Lehnert Corvin Grass Freya Sandberg Elias Hamann Marcus Zuber Thomas van de Kamp Stanislav N. Gorb The ectoparasitic seal louse, Echinophthirius horridus, relies on a sealed tracheal system and spiracle closing apparatus for underwater respiration Communications Biology |
| title | The ectoparasitic seal louse, Echinophthirius horridus, relies on a sealed tracheal system and spiracle closing apparatus for underwater respiration |
| title_full | The ectoparasitic seal louse, Echinophthirius horridus, relies on a sealed tracheal system and spiracle closing apparatus for underwater respiration |
| title_fullStr | The ectoparasitic seal louse, Echinophthirius horridus, relies on a sealed tracheal system and spiracle closing apparatus for underwater respiration |
| title_full_unstemmed | The ectoparasitic seal louse, Echinophthirius horridus, relies on a sealed tracheal system and spiracle closing apparatus for underwater respiration |
| title_short | The ectoparasitic seal louse, Echinophthirius horridus, relies on a sealed tracheal system and spiracle closing apparatus for underwater respiration |
| title_sort | ectoparasitic seal louse echinophthirius horridus relies on a sealed tracheal system and spiracle closing apparatus for underwater respiration |
| url | https://doi.org/10.1038/s42003-025-08285-4 |
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