Discovering unknown Madagascar biodiversity: integrative taxonomy of raft spiders (Pisauridae: ).

Madagascar is a global biodiversity hotspot, but its biodiversity continues to be underestimated and understudied. Of raft spiders, genus Latreille, 1804, literature only reports two species on Madagascar. Our single expedition to humid forests of eastern and northern Madagascar, however, yielded a series of exemplars representing both sexes of five morphospecies. To avoid only using morphological diagnostics, we devised and tested an integrative taxonomic model for based on the unified species concept. The model first determines morphospecies within a morphometrics framework, then tests their validity species delimitation using COI. It then incorporates habitat preferences, geological barriers, and dispersal related traits to form hypotheses about gene flow limitations. Our results reveal four new species that we describe from both sexes as , , , and The range of Silva & Griswold, 2013, now also known from both sexes, is expanded to eastern Madagascar. By increasing the known raft spider diversity from one valid species to five, our results merely scratch the surface of the true species diversity on Madagascar. Our integrative taxonomic model provides the framework for future revisions of raft spiders anywhere.