Diversity patterns of free-living marine nematodes in tropical seagrass beds are understudied. Here, we describe the species richness and assemblage composition of nematodes in 13 seagrass sites covering the whole Cuban archipelago. Nematodes were collected from Thalassia testudinum seagrass beds and identified to species level. We provide a checklist of nematode species from seagrass beds. The species richness of nematode assemblages is high, with 215 species, 138 genus, 35 families, seven orders and two classes. That γ-diversity is higher than other studies and points to seagrass beds as diversity hotspots of free-living marine nematodes. Local species richness in seagrass bed sites is about 57 ± 17 species and broadly similar across the sites, despite the environmental heterogeneity. The geographical distance plays a weak, but significant, role on the decay of similarity likely affected by limited dispersal of nematodes. The pairwise similarity values, related to poor-coloniser nematodes, were twice more affected by the distance than those related to good-colonisers, possibly due to differential success of transport and settlement.

中文翻译：

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古巴群岛（加勒比海）海草床上自由活动线虫组合的多样性模式

对热带海草床中自由生存的海洋线虫的多样性模式进行了研究。在这里，我们描述了覆盖整个古巴群岛的13个海草场所中的线虫的物种丰富度和组合组成。线虫是从地中海藻的海藻床中收集并鉴定到物种水平的。我们提供了来自海草床的线虫种类的清单。线虫组合的物种丰富度很高，有215种，138个属，35个科，7目和2类。γ多样性高于其他研究，并指出海草床是自由活动海洋线虫的多样性热点。尽管环境异质性，海草床位的当地物种丰富度约为57±17种，并且在整个位点大致相似。地理距离起着微弱但重要的作用，线虫的有限散布可能影响相似性衰减的作用。与定殖能力较弱的线虫有关的成对相似度值受距离的影响要比对优良定殖线虫的成对相似度大两倍，这可能是由于运输和定居的成功不同所致。