Sea turtles migrate thousands of miles annually between foraging and breeding areas, carrying dozens of epibiont species with them on their journeys. Most sea turtle epibiont studies have focused on large-sized organisms, those visible to the naked eye. Here, we report previously undocumented levels of epibiont abundance and biodiversity for loggerhead sea turtles (Caretta caretta), by focusing on the microscopic meiofauna. During the peak of the 2018 loggerhead nesting season at St. George Island, Florida, USA, we sampled all epibionts from 24 carapaces. From the subsamples, we identified 38,874 meiofauna individuals belonging to 20 higher taxa. This means 810,753 individuals were recovered in our survey, with an average of 33,781 individuals per carapace. Of 6992 identified nematodes, 111 different genera were observed. To our knowledge, such levels of sea turtle epibiont abundance and diversity have never been recorded. Loggerhead carapaces are without doubt hotspots of meiofaunal and nematode diversity, especially compared to other non-sedimentary substrates. The posterior carapace sections harbored higher diversity and evenness compared to the anterior and middle sections, suggesting increased colonization and potentially facilitation favoring posterior carapace epibiosis, or increased disturbance on the anterior and middle carapace sections. Our findings also shed new light on the meiofauna paradox: “How do small, benthic meiofauna organisms become cosmopolitan over large geographic ranges?” Considering high loggerhead epibiont colonization, the large distances loggerheads migrate for reproduction and feeding, and the evolutionary age and sheer numbers of sea turtles worldwide, potentially large-scale exchange and dispersal for meiofauna through phoresis is implied. We distinguished different groups of loggerhead carapaces based on divergent epibiont communities, suggesting distinct epibiont colonization processes. These epibiont observations hold potential for investigating loggerhead movements and, hence, their conservation.

中文翻译：

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Log海龟上的Meiofauna生活-挑战Meiofauna悖论的结构多样的丰度和生物多样性热点

海龟每年在觅食和繁殖区域之间迁移数千英里，并在旅途中携带数十种表观生物物种。大多数海龟外生体研究都集中在肉眼可见的大型生物上。在这里，我们报告了先前未记录的黑头海龟（Caretta caretta）的表观生物量和生物多样性水平），着重于显微介壳动物。在美国佛罗里达州圣乔治岛的2018年黑logger筑巢季节的高峰期，我们对24个甲壳动物的所有表皮动物进行了采样。从子样本中，我们确定了38,874个隶属于20个较高类群的鱼类。这意味着在我们的调查中，有810,753个人被恢复，每个甲壳平均有33,781个人。在6992个已鉴定的线虫中，观察到111个不同属。据我们所知，从未记录到这样水平的海龟外生体丰度和多样性。ger头甲壳虫无疑是铁皮和线虫多样性的热点，特别是与其他非沉积底物相比。与前部和中部相比，后甲部分具有更高的多样性和均匀性，提示定植增加和可能的便利化有利于后甲壳的流行，或者对前甲壳和中甲壳的干扰增加。我们的研究结果也揭示了meiofauna悖论的新发现：“小型底栖的meiofauna生物如何在较大的地理范围内成为世界性的？” 考虑到高额epi的外生菌定植，长距离migrate的迁移是为了繁殖和觅食，世界范围内海龟的进化年龄和绝对数量，暗示了通过电泳法可能对大型动物进行大规模交换和扩散。我们基于不同的表生生物群落区分了不同的头甲壳动物群，表明了不同的表生生物定殖过程。这些表观动物的观察具有调查顶头运动的潜力，因此，