Multispecies multicolor: resolving the century-old taxonomic trouble of Geoplana multicolor (Platyhelminthes: Geoplanidae)

Abstract

ABSTRACT Geoplana multicolor Graff, 1899 was described based on the external characters of a single specimen collected in São Paulo, southeastern Brazil. Posteriorly, its anatomy was described based on specimens considered conspecific collected in several nearby localities, despite differences in the color pattern. The internal anatomy of the holotype was unknown until now, making identifying G. multicolor problematic, a worrying situation considering its current status as the type species of Paraba. To perform a taxonomic revision, we analyzed the anatomy of the holotype of G. multicolor deposited at the Zoologisches Museum Hamburg and concluded that its morphology matches the current definition of Geoplana. Thus, we propose the revalidation of Geoplana multicolor Graff, 1899 stat. rev. Since the type-species of Paraba returned to Geoplana and Paraba becomes a junior synonym of Geoplana, we propose a new genus, Paraparaba gen. nov., for species previously in Paraba. Considering that the basis for the identification of G. multicolor has been the description of the anatomy of specimens sampled and studied by Marcus (1951), which correspond to a different species now included into Paraparaba, we propose a new nominal species for Geoplana multicolor sensu Marcus, Paraparaba impositrix gen. nov., sp. nov. We suggest a thorough revision of further material studied by subsequent authors, sampled in different Brazilian regions and Argentina, using Marcus’ description as the basis for identification.

Keywords

• Geoplaninae
• land flatworms
• morphology
• taxonomy
• Paraba