Two species previously known from East Kazakhstan, Acantholycosa katunensis Marusik, Azarkina & Koponen, 2004, known from the holotype male, and A. kurchumensis Marusik, Azarkina & Koponen, 2004, syn. n. known from females, are synonymized, and priority is given to A. katunensis. Acantholycosa katunensis is reported for the first time in the Russian Altai. Both sexes of this species are illustrated, and a distribution map is provided.

Aranei , wolf spider, South Siberia, Russia, new record, new synonymy

Acantholycosa Dahl, 1908 is one of the best studied among species-rich Pardosinae genera in the Holarctic due to a revision (Marusik et al. 2004), a regional review (Marusik and Omelko 2011) and several species surveys (Kronestedt and Marusik 2002; Fomichev and Marusik 2011; Marusik and Logunov 2011). Nevertheless, its taxonomy has remained improperly studied. Over one third of Acantholycosa species are known from only a single sex (two from females and eight from males). All these species are either endemic to the Altai-Sayan Mountain region (nine species) or the Sikhote-Alin’ Mountain Range (one species). Such a high number of species known only from one sex may be because of the habitat preference of Acantholycosa species. With one exception (A. lignaria (Clerck, 1757)), all species inhabit stony screes in mountains, and this habitat is difficult to reach and study. So far, 29 species are known in the genus (World Spider Catalog 2015), most of which (20) occur in the Altai-Sayan Mountain region (Marusik et al. 2004).

While studying material from the Russian Altai, the first author found two species from nearby localities, A. katunensis Marusik, Azarkina & Koponen, 2004 and A. kurchumensis Marusik, Azarkina & Koponen, 2004, both previously known from East Kazakhstan. The former species, assigned to the azyuzini-group, was known from the holotype male from Rakhmanovskiye Klyuchi Village, and the latter species, assigned to the dudkorum-species group, was known from three females from two localities, the Kurchum River and Rakhmanovskiye Klyuchi. Marusik et al. (2004) suggested that these two species found in a single locality (Rakhmanovskiye Klyuchi) could be conspecific. The occurrence of these two species A. katunensis and A. kurchumensis in another locality led us to the conclusion that they are conspecific, and the tentative placement of these species into different species groups by Marusik et al. (2004) was incorrect. Additional arguments in support of the conspecificity of two species are the same spination of tibia I (5-6 proventral and 4-5 retroventral spines) and also that these species in South-Western Altai are the only known species by opposite sexes. The goal of this paper is to synonymize the two species, provide an illustrated redescription of both sexes and new data about species distribution.

Specimens were photographed with a Canon EOS 7D camera attached to an Olympus SZX16 stereomicroscope at the Zoological Museum, University of Turku, Finland. Digital images were montaged using “CombineZP” image stacking software. Epigynes were cleared in a KOH/water solution until soft tissues were dissolved. Photographs were taken in dishes with paraffin on the bottom to hold the specimens in position. Background maps are from Microsoft Encarta Premium 2009. All material examined is deposited in the Institute for Systematic and Ecology of Animals, Novosibirsk (ISEA).

Synonymizing these two names reduced the number of species known in the genus to 27. Although the number of Acantholycosa species in the Altai-Sayan Mountain Region decreased from 20 to 19, this region still has the highest species diversity and endemism (59%) in the entire range of the genus. The record of A. katunensis from the Russian Altai increased the number of Acantholycosa species found in Russia from 21 to 22. Judging from the high level of endemism in the Altai-Sayan Mountain Region, the limited distribution of species in that area, habitat preferences (stony screes) and the number of unexplored mountain ranges in the West and East Sayan Mountains (cf. Marusik et al. 2004: map 1) and the lack of material from adjacent Xinjiang (China) and Mongolia, many new species are expected.

We are grateful to R.V. Yakovlev (Barnaul, Russia), S.Yu. Sinev (Saint Petersburg, Russia) and A.V. Pershin (Biysk, Russia) for their help organizing the field trip to the Altai in which the material treated in this paper was collected. We also thank G.N. Azarkina (ISEA) for providing access to the comparative material from the ISEA. English of the earlier draft was kindly checked by Sarah Crews (CAS, USA).