Castaways: the Leeward Antilles endemic spider genus Papiamenta (Araneae: Pholcidae)
Abstract
Ninetinae are a group of small to tiny short-legged spiders largely restricted to arid habitats. Among daddy-long-legs spiders (Pholcidae) they are by far the least diverse subfamily, but this may partly be a result of inadequate collecting, poor representation in collections, or scientific neglect. Here we build on a large recent collection of the ninetine genus Papiamenta Huber, 2000 from the Leeward Antilles, and use cytochrome oxidase 1 (CO1) sequences, extensive scanning electron microscopy data, transmission electron microscopy data, and karyotyping to analyze this geographically isolated and poorly known island genus. CO1 sequences support the split between the two morphologically distinct species on Curaçao, but genetic distances between them are surprisingly low (7.4–9.8%; mean 8.6%). The type species P. levii (Gertsch, 1982) may include more than one species, but CO1 and morphology suggest conflicting clade limits. A third species, P. bonay Huber sp. nov., is newly described from Bonaire. Our data on sperm ultrastructure and karyology are puzzling as they suggest different phylogenetic affinities of Papiamenta to other genera. Males transfer sperm as individual sperm (cleistosperm), which agrees with its putative closest relatives as suggested by molecular data, the North American genera Pholcophora and Tolteca. The sex chromosome system (X1X2X3Y) of P. levii, however, is the same as in the South American Ninetinae genera Gertschiola and Nerudia but very different from its putative closest relatives.