Dead urchin walking: resilience of an arctic Strongylocentrotus to severe skeletal damage

Abstract The ability of bottom-dwelling marine fauna to repair injured body parts is critical to the survival of individuals from disturbances that inflict wounds. The phylum Echinodermata, in particular, exposes a pronounced ability to regenerate skeletal damages. Regeneration of lost body parts of...

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Bibliographic Details
Published in:Polar Biology
Main Authors: Wisshak, Max, Neumann, Christian
Other Authors: Deutsche Forschungsgemeinschaft
Format: Article in Journal/Newspaper
Language:English
Published: Springer Science and Business Media LLC 2020
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Online Access:http://dx.doi.org/10.1007/s00300-020-02634-1
http://link.springer.com/content/pdf/10.1007/s00300-020-02634-1.pdf
http://link.springer.com/article/10.1007/s00300-020-02634-1/fulltext.html
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Summary:Abstract The ability of bottom-dwelling marine fauna to repair injured body parts is critical to the survival of individuals from disturbances that inflict wounds. The phylum Echinodermata, in particular, exposes a pronounced ability to regenerate skeletal damages. Regeneration of lost body parts of stellate echinoderms (crinoids, asteroids and ophiuroids) is a well-documented phenomenon, whereas sea urchins (echinoids) have received much less attention. Here we report, for the first time, a field observation on an adult sea urchin of the genus Strongylocentrotus in its natural habitat, exposing severe skeletal damage but remarkable survivorship. The sea urchin was revealed by analysing a time series of seafloor images taken during a lander deployment in a rhodolith bed in the polar waters of northern Spitsbergen, Svalbard. Despite the loss of half the aboral region of the test, including existential organs, the sea urchin continued to move across the seafloor for more than 43 h, thereby escaping another predation attack by a large crab. The observed behaviour is grounded in the peculiarity of the sea urchins’ nervous system where locomotion is controlled by a decentralised ectoneural system in the epithelium, large parts of which had remained intact after the traumatic event. Our field observation thus documents initial post-traumatic survival of severe lesions, which is a basic prerequisite for beginning repair processes.