Patterns of diversity in microscopic animals: are they comparable to those in protists or in larger animals?

Aim General patterns of biodiversity, such as latitudinal gradients and species-area relationships, are found consistently in a wide range of organisms, but recent results for protist diversity suggest that organisms shorter than 2 mm do not display such patterns. We tested this prediction in bdelloid rotifers, pluricellular metazoans smaller than 2 mm, but with size and ecology comparable to protists.