Trachysphaera corcyraea ( Verhoeff, 1900 )

Antić, Dragan, Šević, Mirko, Macek, Oliver & Akkari, Nesrine, 2021, Review of Trachysphaera Heller, 1858 (Diplopoda: Glomerida: Glomeridae) in Serbia, with taxonomic notes on the genus, Zootaxa 5047 (3), pp. 273-299 : 276-279

1. Trachysphaera corcyraea ( Verhoeff, 1900)

Figs 2 , 3A, B, D , 12A .

Gervaisia costata corcyraea Verhoeff, 1900: 185 , 186, fig. 4.

Gervaisia corcyraea — Verhoeff (1906: 791, 800, 809, 810, 816, 821; 1908: 529); Attems (1929: 469; 1943: 78, 79, 88, fig. 24).

Gervaisia corcyrea (sic!)— Tabacaru (1958: 160; 1960: 319).

Trachysphaera corcyraea — Strasser (1974: 222); Tabacaru (1988: 54); Kime & Enghoff (2011: 35, 125).

Gervaisia rotunda (sic!) (= recte rotundata )— Attems (1943: 85, figs 17–19), misidentification.

Trachysphaera attemsi Golovatch, 1976: 41 (nomen novum pro rotundata sensu Attems (1943)) , syn. n.

Material examined. Serbia ( IZB): 2 ♂♂, 2 ♀♀, Samar Cave, village Kopajkošara , near Niš, 18.06.2001, S. Ognjenović leg. ; 11 ♂♂, 9 ♀♀, 2 juveniles, same locality, but 19– 20.10.2005, S. Ognjenović leg. ; 2 ♂♂, 3 ♀♀, same locality, but 26.06.2012, D.Antić leg. ; 1 ♂, no-name cave in the valley of Radovanska River, village Jablanica , near Boljevac, 04.08.2008, D. Antić leg. ; 1 ♂, Izviđačka Cave, Suvaja Canyon, village Strmosten , near Despotovac, 24.05.2014, S. Ćurčić leg. ; 2 ♂♂, 1 ♀, 1 juvenile, Cerjanska Cave, village Cerje , near Niš, 29.10.2017, D. Antić & C. Oláh leg. Greece ( NHMW): Corfu : 6 ex. ( NHMW MY1848 ), G. Paganetti leg. ; 4 ex. ( NHMW MY1849 ), C. Attems leg. ; 29 ex. ( NHMW MY1850 ), 28.04.1900, C. Attems leg. ; Epirus: 100 ex. determined as “ Gervaisia rotunda ” (NHMW MY1851) , Mount Xerovouni, Nisista locality, village Rodavgi , 07.06.1933, M. Beier leg.

Remarks. Verhoeff (1900: 185) originally described his corcyraea as a subspecies of Gervaisia costata ( Waga, 1857 a) . Based on the presence of a medial hump on the anal shield ( Figs 2A–G , 3A, B ), Verhoeff (1900) immediately compared corcyraea to Trachysphaera gibbula ( Latzel, 1884) , a species with a striking hump on the anal shield ( Fig. 3C ). He also recognized the similarity in telopod structure in both species characterized by a concave lateral margin on the telopod tibia ( Figs 2J, K , 3D, E ). In fact, the telopods of both species are not just similar, but al- most identical. Besides the aforementioned concave lateral margin on the tibia, this telopoditomere is characterized by the presence of a small posterior nodule (the same structure present in numerous other Trachysphaera species ). Further, the tarsus appears to be very short in both species, the syncoxite is with a low, rounded, medial lobe bearing short setae, and with well-developed and acuminate syncoxital horns curved at mid-length and with their apices pointing laterad, with setae more pronounced at the mesal margin and directed proximad. The syncoxital horns seem to be more robust with longer mesal setae in T. gibbula . In addition to this small difference in the structure of the syncoxital horns, T. corcyraea and T. gibbula clearly differ by the size of the medial hump on the anal shield. This structure is more pronounced in T. gibbula and very obvious in both sexes, albeit less strongly developed in females [see Golovatch (2010: 4, figs 8–12)]. On the other hand, the medial hump is less strongly developed in T. corcyraea , being obvious only in males from dorsal, ventral and lateral views ( Figs 2A, C, E–G , 3B ), while in females it is almost absent and hardly if at all visible ( Fig. 3A ). This is especially true for Serbian populations, and not only for females ( Fig. 2B, D ), but sometimes also for males. The medial hump is hardly visible or absent in juveniles ( Fig. 3A ).

Since its original description, and up to the present study, T. corcyraea has been studied only by Attems (1943: 88, fig. 24), who examined topotype material from Corfu Island in Greece. In the same paper, he also treated Tra- chysphaera material from Mount Xerovouni, Nisista locality, near the village of Rodavgi, Epirus, Greece, some 100 air-km away from Corfu. Interestingly, despite the great similarity in the telopod structure and the geographic proximity between T. corcyraea and T. gibbula, Attems (1943: 85 , figs 17–19) identified the material from Epirus as at that time the Caucasian endemic T. rotundata Lignau, 1911 (= T. costata ). Given the great distance between the Epirotian and Caucasian populations of rotundata, Strasser (1974: 222) questioned Attems’ identification. Realizing a significant difference in telopod structure between Lignau’s and Attems’ rotundata, Golovatch (1976: 41) proposed a new name for the population from Epirus, T. attemsi Golovatch, 1976 . Only a few years later, bearing in mind that T. rotundata was widespread throughout the Caucasus, and based on the discovery of this species in northern Iran, did Golovatch (1981: 423–425) suggest that very possibly Attems had had T. rotundata from Epirus, and synonymized his T. attemsi with T. rotundata . Recently, T. rotundata has been synonymized with T. costata by Golovatch (2008: 100–103), thus T. attemsi from Epirus automatically became a synonym of T. costata .

Despite the clear similarity in the structures of the telopods, as well as geographical proximity, it is obvious that none of the previous authors, including Attems (1943) himself, noticed a link between the population from Epirus and T. corcyraea . After the examination of the topotypic material of T. corcyraea from Corfu, as well as Attems’ material from Epirus, our assumption that the population from Epirus belongs to T. corcyraea is confirmed here. With this in mind, T. attemsi syn. n. has been transferred to the list of synonyms of T. corcyraea . Here, probably belongs the material of “ T. rotundata (= costata ) from? Epirus ”, examined by Golovatch (1990). Attems (1943: 85, fig. 19) drew his T. rotundata with a telopod syncoxite bearing two lobes, but we assume this must have been an error caused by a different angle of observation.

The newly discovered Serbian populations of T. corcyraea , found only in a few caves in the Carpatho-Balkan Arc, quite far from the Greek populations, may suggest that this species either could have been completely overlooked in the geographic area separating these territories or the fact that cave populations in Serbia are relicts of a formerly more widespread species. Additionally, as the medial hump on the anal shield is less strongly developed in the Serbian populations than in the Greek ones, the possibility that Serbian populations may represent another species closely related to T. corcyraea and T. gibbula cannot be totally excluded. Another hypothesis is that these are just representatives of one species, T. gibbula by priority, with a poorly developed medial hump in the southern populations.

The species is new to the Serbian fauna.

Type locality. Corfu , Greece .

General occurrence. Corfu and Mount Xerovouni in Greece, and eastern Serbia.

Occurrence in Serbia. Known only from a few caves in eastern Serbia ( Fig. 12A ).

Figures

FIGURE 2. Trachysphaera corcyraea (Verhoeff, 1900) from Serbia (IZB). A, G, H–K. ♂♂ from Samar Cave. B–F. Specimens from Cerjanska Cave. A. Habitus, dorsal view. B. ♀, habitus, dorsal view. C. ♂, habitus, lateral view. D. ♀, habitus, lateral view. E. ♂, habitus, ventral view. F. ♂, posterior part of body, dorsal view. G. Posterior part of body, dorsal view. H. Leg-pair 17, anterior view. I. Leg-pair 18, anterior view. J, K. Telopods, anterior and posterior views, respectively. Arrows showing medial hump on anal shield. Scale bars: 1 mm (A–G) and 0.3 mm (H–K).

FIGURE 3. Trachysphaera corcyraea (Verhoeff, 1900) (A, B, D) and T. gibbula (Latzel, 1884) (C, E). A. Topotype specimens from Corfu, Greece (NHMW MY1848). B. ♂ from Xerovouni Mt., Epirus, Greece (ex. rotundata sensu Attems (1943) and at- temsi sensu Golovatch (1976)), habitus, lateral and dorsal views (NHMW MY1851). C. ♂ from Leechwald, Austria, habitus, lateral, dorsal and subventral views (NHMW MY1732). D. ♂ from Xerovouni Mt., Epirus, Greece (ex. rotundata sensu Attems (1943) and attemsi sensu Golovatch (1976)), telopods, anterior view (NHMW MY1851). E. ♂ from Leechwald, Austria, telopods, posterior view (NHMW MY1732). Arrows showing medial hump on anal shield. Scale bars: 1 mm (A–C) and 0.2 mm (D, E).

FIGURE 12. Distribution of the genus Trachysphaera Heller, 1858 in Serbia. A. Identified specimens. B. Unidentified specimens.