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.

中文翻译：

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死海胆行走：北极Strongylocentrotus对严重骨骼损伤的恢复能力

底栖海洋动物修复受伤身体部位的能力对于个体免受造成创伤的干扰的生存至关重要。棘皮动物门尤其具有显着的再生骨骼损伤的能力。星状棘皮动物（海百合、小行星和鸦片类动物）丢失的身体部位的再生是一个有据可查的现象，而海胆（海胆类）受到的关注要少得多。在这里，我们首次报告了在其自然栖息地中对 Strongylocentrotus 属的成年海胆进行的实地观察，暴露了严重的骨骼损伤但存活率很高。通过分析在斯瓦尔巴群岛斯匹次卑尔根岛北部极地水域的红石床中部署着陆器期间拍摄的海底图像的时间序列，发现了海胆。尽管测试中失去了一半的离岸区域，包括存在器官，海胆继续在海底移动超过 43 小时，从而逃脱了另一只大螃蟹的捕食攻击。观察到的行为基于海胆神经系统的特殊性，其中运动是由上皮中分散的外神经系统控制的，其中大部分在创伤事件后保持完整。因此，我们的现场观察记录了严重病变的初始创伤后存活，这是开始修复过程的基本先决条件。观察到的行为基于海胆神经系统的特殊性，其中运动是由上皮中分散的外神经系统控制的，其中大部分在创伤事件后保持完整。因此，我们的现场观察记录了严重病变的初始创伤后存活，这是开始修复过程的基本先决条件。观察到的行为基于海胆神经系统的特殊性，其中运动是由上皮中分散的外神经系统控制的，其中大部分在创伤事件后保持完整。因此，我们的现场观察记录了严重病变的初始创伤后存活，这是开始修复过程的基本先决条件。