A new monotypic, gift-giving spider genus from the Neotropical Pacific region: Dobarakuku gen. nov. (Araneae, Pisauridae)

The nursery web spider Tinus ursus Carico, 1976 was originally described based on female specimens from Costa Rica. In this study, we describe for the first time the male of the species, providing the first records from Colombia, and documenting its sexual behavior, including courtship and nuptial gift production. The previously unknown male palp revealed a unique combination of characters that prompted us to reassess the phylogenetic placement of T. ursus using morphological, behavioral and molecular evidence.

Our analyses demonstrate that T. ursus does not belong to Tinus F. O. Pickard-Cambridge, 1901, but instead forms a distinct lineage sister to the clade comprising Tinus and Thaumasia Perty, 1833. In light of these results, we transfer the species to a new monotypic genus, Dobarakuku gen. nov., designating Dobarakuku ursus (Carico, 1976) comb. nov. as the type species. In addition, we recognize Thaumasiinae Petrunkevitch, 1928 as comprising four genera: Architis Simon, 1898a, Dobarakuku gen. nov., Thaumasia, and Tinus.

The proximal tegular projection may constitute a potential morphological synapomorphy of Thaumasiinae, secondarily lost in Architis. Dobarakuku gen. nov. differs from all other Neotropical Pisauridae genera by a unique combination of characters, including a narrow distal tegular projection, vestigial median apophysis, laminar hyaline conductor, stout embolus, and a pair of oval atria in the epigynum. The courtship behavior of D. ursus comb. nov. resembles that of other Pisauridae species, and the production of nuptial gifts makes it the sixth species in the family known to exhibit this behavior.