Eight new Lepadellidae (Rotifera, Monogononta) from the Congo bring to level endemism in Africa's rotifers

While patterns in diversity and biogeography of macroscopic organisms may be fairly well-documented, this is much less the case for microscopic organisms, for which mechanisms working at entirely different scales may be relevant. Data deficiency remains a major obstacle to the study of these mechanisms, and this situation is exacerbated in regions for which accessibility is not self-evident. We here report on the Lepadellidae rotifers in zooplankton samples collected during the Boyekoli ebale Congo 2010 expedition and a subsequent visit to Yangambi, DR Congo in June 2012. The material contained eight hitherto unknown species amongst 33 Lepadellidae taxa. This remarkable result illustrates a previously unknown and largely endemic microfauna of the Congo Basin and refutes the African anomaly hypothesis on the purported poverty of the Central African rotifer fauna. We describe the new species, viz. Colurella asymmetrica n. sp., Lepadella hanneloreae n. sp., L. jingruae n. sp., L. weijiai n. sp., L.wilungulai n. sp., L. yangambi n. sp., Squatinella curviseta n. sp. and S. longipila n. sp., and comment on the diversity and biogeographical relationships of this fauna. Two of the new species appear to have a South American congener as their closest relative, potentially constituting two more examples of rare African-South American vicariant species-pairs in Rotifera.