Ecological differentiation in cryptic rotifer species: what we can learn from the Brachionus plicatilis complex

In recent decades, the use of molecular techniques in rotifers has revealed the existence of many cryptic species. Although strong competition is expected among cryptic species, these species are often sympatric. Here, we present a review of sympatric cryptic rotifer species, focusing on those cases in which niche differentiation has been investigated. There are at least 42 cryptic rotifer species complexes, and species coexistence is commonly...