On the mysterious Seychellois endemic spider genus Cenemus (Araneae, Pholcidae)

Abstract

The Pholcidae subfamily Smeringopinae has been revised extensively over the last decade, and most of its currently eight genera can now be placed with some confidence in the phylogeny of the family. A notable exception has been the endemic Seychellois genus Cenemus Saaristo, 2001. Morphologically, the genus is mainly characterized by plesiomorphies, which resulted in weakly supported and unstable positions in previous cladistic analyses. Molecular data have not previously been available. Here we revise the morphology of the type species Cenemus culiculus (Simon, 1898), including first SEM photos, and present the first molecular data for the genus. Morphology and molecules continue to give conflicting results regarding the sister taxon of Cenemus, but our analyses strongly support a position of the genus within the northern group of Smeringopinae (Northern Africa and the Mediterranean to India) rather than in the southern group (Subsahara Africa). This supports the idea that Cenemus is an ancient taxon, dating back to the breakup of Gondwana, between the separation of the Mascarene platform from Madagascar (~85 mya) and its separation from India (~60 mya). In addition, we present first molecular data for the recently established Smeringopinae genus Maghreba Huber, 2022, which is consistently resolved as sister to Crossopriza Simon, 1893; we present molecular evidence for the polyphyly of Holocnemus Simon, 1873, supporting previous morphological evidence; and we present an annotated list of the Pholcidae of the Seychelles, most of which are supposedly recent human introductions.