The presence of non-indigenous species outside their home range attracts growing attention by the scientific community, as well as policy makers and common citizens. However, dispersal pathways of most non-indigenous species remain poorly understood. The association between non-indigenous and indigenous species may facilitate dispersal in non-native habitats. Identifying such associations is therefore paramount, but few studies have addressed this issue to date. The present work reports the association between the non-indigenous spider crab Pyromaia tuberculata, morphologically and molecularly identified, with the autochthonous scyphomedusa Catostylus tagi in European waters. This is the first time this widespread invasive brachyuran crab is described associated with jellyfish. In the laboratory, P. tuberculata was observed feeding on the gonadal tissues of its cnidarian host, although this behaviour needs to be confirmed in the wild. The association between P. tuberculata and C. tagi raises awareness on how the dispersal potential of this non-indigenous species may be significantly enhanced. As recommended by the Marine Strategy Framework Directive, it is important to include P. tuberculata in the European monitoring programmes of non-indigenous species. Future studies should continue to investigate the prevalence of this specific association, as well as other associations between jellyfish and non-indigenous fauna, as an early warning initiative. Researchers may benefit from ongoing citizen science projects to gather data on this overlooked pathway for dispersal of non-indigenous species.

非本地物种在其家园范围之外的存在引起了科学界以及政策制定者和普通公民的日益关注。但是，大多数非本土物种的传播途径仍然知之甚少。非土著物种与土著物种之间的联系可以促进在非本地生境中的扩散。因此，识别此类关联至关重要，但是迄今为止，很少有研究解决此问题。本工作报告形态和分子学上确定的非本地蜘蛛蟹Pyromaia tuberculata与本地夜蛾Cyostylus tagi之间的关联在欧洲水域。这是首次将这种广泛侵入性的短臂蟹与水母联系起来。在实验室中，观察到结核分枝杆菌以其刺胞宿主的性腺组织为食，尽管这种行为需要在野外确认。P. tuberculata和C. tagi之间的联系提高了人们对如何显着增强这种非本土物种的扩散潜力的认识。根据《海洋战略框架指令》的建议，重要的是要包括结核杆菌在欧洲非本土物种监测计划中。作为早期预警计划，未来的研究应继续调查这种特定关联以及水母与非本地动物之间的其他关联的患病率。研究人员可能会从正在进行的公民科学项目中受益，以收集有关这一非土著物种传播途径的数据。