Scotospilus longus, Zhang, Zhi-Sheng, Li, Shuqiang & Pham, Dinh-Sac, 2013

Zhang, Zhi-Sheng, Li, Shuqiang & Pham, Dinh-Sac, 2013, First description of comb-tailed spiders (Araneae: Hahniidae) from Vietnam, Zootaxa 3613 (4), pp. 343-356 : 354-355

Discussion on Scotospilus and S. longus sp. nov.

The determination of Scotospilus longus sp. nov. is not easy. The diversity of Hahniidae is far from clear, especially in Southeast Asia. Biogeographically, spiders of Vietnam should be related with those from Oriental and Australian area. Our comparison with Asian Hahniidae spiders shows the new species has a strongly extended RTA proximally (excluded by Hahnia and Alistra ) and no stridulatory files near the petiolus (rejected by Antistea and Neoantistea ). The further comparison with Australian comb-tailed spiders shows that male palp of the new species is similar to that of Scotospilus nelsonensis (Forster, 1970) and S. plenus (Forster, 1970) from New Zealand. Male of these 3 species share a small tuberculate patellar apophysis with a tip, a strongly extended tibial apophysis approaching or exceeding the base of patella and a retrolaterally originated embolus extending almost a circle. But female of the new species is different from the others, which has a single copulatory opening centrally, the wide copulatory ducts and the absence of subspermathecae (second spermathecae or receptacula). A thorough check of papers for all Hahniids throughout the world was also done, but no closer species found than those from New Zealand.

Epigyne of Hahniidae was thought more important for the species’ identification than male palp (Brignoli 1986), but in our mind, male palp should be of great concern for the species’ generic decision. We prefer to put this new species into Scotospilus , rather than propose a new genus for the single species. There are a lot of epigynes or vulvae of Hahniidae not given or not shown very well in the literatures due to its quite small size. The exhaustive research on this group is badly needed.

The genus Scotospilus was erected by Simon (1886) for only the female of the generotype, S. bicolor Simon, 1886 from Tasmania island of Australia, which male was supplied by Hickman (1948). Lehtinen (1967) transfer the second species from Hahnia , S. maindroni (Simon, 1906) , which was described only on female from India with only a small epigynal figure given by Lehtinen. Brignoli (1986) synonymized Tuana Forster, 1970 with Scotospilus based on “the similarity” of generotype and four Tuana species originally described by Foster, 1970, which were combined as: S. divisus (female), S. nelsonensis (male, female), S. plenus (male, female) and S. westlandicus (female). And Brignoli (1986) also transferred two other Tasmanian species originally placed in Hahnia and Neoaviola by Hickman (1948) in here: S. ampullarius (male, female) and S. wellingtoni (male, female). But as our opinion, judged from the descriptions and figures of Simon (1886; 1906), Hickman (1948), Lehtinen (1967) and Forster (1970), although all of them have posteriorly located tracheal spiracle, the RTA of generotype is closer to S. ampullarius than others in having the anteriorly pointing RTA and the curved copulatory ducts. Four New Zealand’s species, S. divisus , S. nelsonensis , S. plenus and S. westlandicus and the Tasmanian one, S. ampullarius seems to form a firm group in having the strongly curved RTA proximally, the relatively short copulatory ducts and the posteriorly located spermathecae with narrower distance than the diameter of it. There is no evidence to prove S. maindroni have close relationship with all other Scotospilus species. Here the new species, S. longus sp. nov. is somewhat similar to S. plenus etc. for the similar RTA and the narrow distance of spermathecae.