Data from: The specific and exclusive microbiome of the deep-sea bone-eating snail, Rubyspira osteovora

Rubyspira osteovora is an unusual deep-sea snail from Monterey Canyon, CA. This group has only been found on decomposing whales and is thought to use bone as a novel source of nutrition. This study characterized the gut microbiome of R. osteovora, compared to the surrounding environment, as well as to other deep-sea snails with more typical diets. Analysis of 16S rRNA gene sequences revealed that R. osteovora digestive tissues hosted a much lower bacterial diversity (average Shannon index of 1.9; n = 12), compared to environmental samples (average Shannon index of 4.4; n = 2) and were dominated by two bacterial genera: Mycoplasma and Psychromonas (comprising up to 56% and 42% average total recovered sequences, respectively). These two bacteria, along with Psychrilyobacter sp. (∼16% average recovered sequences), accounted for between 43–92% of the total recovered sequences in individual snail digestive systems, with other OTUs present at much lower proportions. The relative abundance of these three groups remained similar over six years of sampling (collection date was not shown to be a significant predictor of community structure), suggesting a long-term association. Further, these bacterial genera were either not present (Mycoplasma and Psychromonas), or at very low abundance (< 0.04% for Psychrilyobacter), in environmental samples and other deep-sea gastropods, supporting the uniqueness of the R. osteovora gut microbiome.

Rubyspira osteovora 是一种产自美国加利福尼亚州蒙特利峡谷的特殊深海螺类。该类群仅在腐烂鲸类遗体上被发现，被认为以鲸骨作为新型营养来源。本研究对R. osteovora的肠道微生物组进行了表征，并将其与周边环境以及食性更具典型性的其他深海螺类进行了对比。对16S rRNA基因序列的分析结果显示，与环境样本（平均香农指数（Shannon index）为4.4，样本量n=2）相比，R. osteovora消化组织内的细菌多样性显著更低（平均香农指数（Shannon index）为1.9，样本量n=12），且主要由两个菌属主导：支原体属（Mycoplasma）和嗜冷杆菌属（Psychromonas），二者分别占总回收序列的平均比例高达56%和42%。这两种细菌，再加上Psychrilyobacter sp.（平均占总回收序列约16%），在单只螺类的消化系统总回收序列中占比可达43%至92%，其余操作分类单元（OTU）的占比则极低。这三类菌群的相对丰度在为期6年的采样中保持稳定，采样日期未被证实为群落结构的显著预测因子，表明该螺类与其肠道菌群之间存在长期的共生关联。进一步研究发现，这些菌属在环境样本以及其他深海腹足类中要么完全不存在（支原体属和嗜冷杆菌属），要么丰度极低（Psychrilyobacter sp. 丰度<0.04%），这佐证了R. osteovora肠道微生物组的独特性。