Trachysphaera similicostata ( Radu & Ceuca, 1951 )

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 : 292-294

6. Trachysphaera similicostata ( Radu & Ceuca, 1951)

Figs 1H, I , 11 , 12A .

Gervaisia similicostata Radu & Ceuca, 1951: 149–152 , figs 7–13.

Gervaisia similicostata — Strasser (1962: 469).

Gervaisia costata var. similicostata — Strasser (1966: 328).

Trachysphaera similicostata — Ceuca (1975: 87), misidentification; Tabacaru (1988: 59).

Material examined. Serbia ( IZB) : 1 ♂, 3 ♀♀, Suvodolska Cave, Suvodol Monastery, village Selačka , Stara Plani- na Mt. , near Zaječar, 11.2007, A. Zatezalo leg. ; 2 ♀♀, 1 juvenile, no name cave I (smaller), village Temska, Stara Planina Mt. , near Pirot, 10.07.2012, M. Šćiban leg. ; 3 juveniles, same locality, but 21.07.2012, M. Šćiban leg. ; 2 ♀♀, same locality, but 07.07.2020, D. Antić, D. Stojanović leg. ; 7 ex., same locality, but 03.06.2021., D. Antić, M. Šević, D. Stojanović leg. ; 5 ♂♂, 7 ♀♀, no name cave II (bigger), village Temska , near Pirot, 07.07.2020, D. Antić, D. Stojanović leg. ; 12 ♂♂, 8 ♀♀, 3 juveniles, no-name cave, Bela River, village Bela, Stara Planina Mt. , near Pirot, 10.2013, D. Antić leg. ; 6 ♂♂, 1 ♀, 4 juveniles, Velika (= Držinska) Cave , village Držina , near Pirot, 17.07.2012, D. Antić leg. ; 1 ♀, 1 juvenile, same locality, but 05.2016, D. Antić leg. ; 64 ex. (♂♂, ♀♀, juveniles), Fagus forest, near Ponor, Dojkinci village, Stara Planina Mt. , 04.06.2021, D. Antić, M. Šević, D. Stojanović leg.

Remarks. Since its original description from a cave in the Apuseni Mountains in Romania by Radu & Ceuca (1951: 149–152, figs 7–13), this species was examined only a few times. First by Strasser (1962, 1966) who studied a few specimens from Bulgarian caves. Strasser (1966) considered this taxon as a variety of T. costata , expressing his doubts about the validity of this species. Later, Ceuca (1975) recorded T. similicostata from one cave in Turkey, pointing to some differences in the structure of the syncoxital horns between the Turkish and Romanian populations. Tabacaru (1988) concluded that this species needed revision, including the Bulgarian populations. Based on Strasser’s (1966) opinion that T. similicostata was just a variety of T. costata and that the material from Turkey examined by Ceuca (1975) was from the same type locality as T. pigmentifer ( Verhoeff, 1941) (= T. costata ), Golovatch (1990: 344) synonymized T. similicostata under T. rotundata (= T. costata ). Thus, automatically T. similicostata joined the synonymy list of T. costata .

After the examination of a large number of males from a few caves and one epigeic locality in eastern Serbia, we are of the opinion that those belong to T. similicostata , and here we revalidate and revive this taxon from the list of the synonyms of T. costata . The telopods of T. similicostata are more similar, almost identical, to those of three presumed troglobionts described from Romania, viz., T. jonescui ( Brölemann, 1914) , T. orghidani ( Tabacaru, 1958) and T. racovitzai ( Tabacaru, 1960) . All four species are characterized by long and blunt syncoxital horns, while those are acuminate in T. costata (including synonyms). All male specimens examined from Serbia show no variation in the structure of these horns. Further, they show the same configuration of the syncoxital medial lobe, which is high and rounded, covered with setae. A similar lobe can be seen in all three previously mentioned troglobionts. Radu & Ceuca (1951: 151, figs 7–11) depicted several different types of syncoxital lobes in their similicostata . We have not observed such variations, but here we would like to point out that through rotating the syncoxite we have obtained almost the same shapes of syncoxital lobe as noted by Radu & Ceuca (1951) ( Fig. 11G–L ), even in the same male ( Fig. 11J–L ).

One of the main differences between T. similicostata , on the one hand, and T. jonescui , T. orghidani and T. ra- covitzai, on the other hand, lies in the absence of pigmented ommatidia in the latter three species. The samples of T. similicostata from Serbia show variable pigmentation of their ommatidia. The examined specimens featured either well-developed black spots or reduced pigment spots, while one specimen had completely unpigmented ommatidia. Sometimes even the left and the right side of the head differs in this respect in the same specimen. Thus, the presence or absence of pigmented ommatidia seems not to be a very good taxonomic character. Antennomere 6 in those cavedwelling congeners seems to be somewhat elongated. However, we realized this character to be highly variable also in T. similicostata , even within the same population. In any case, it is obvious that T. similicostata is devoid of a high tergal ridge 10, unlike those seen at least in T. orghidani and T. jonescui .

After all, Strasser (1962) could actually have had T. similicostata from Stara Planina in Bulgaria. Our new records of this species from Serbia fit nicely to its presently known distribution in the Carpatho-Balkan Arc. On the other hand, Ceuca (1975) probably misidentified the specimens from Turkey, which could be T. pigmentifer (= T. costata ), for he himself already stated that they differed in the shape of the synxocital horns, the structures we find showing no variability.

The species is new to the Serbian fauna.

Type locality. Cetățile Ponorului , Apuseni Mountains, Transylvania in Romania .

General occurrence. Carpatho-Balkan System in Romania, Serbia and Bulgaria.

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

Trachysphaera sp. (“ costata ” habitus)

Material examined. Serbia ( IZB) : 1 ♀, Resavska Cave, village Jelovac , near Despotovac, 26.10.2020, S. Ćurčić, N. Vesović leg. ; 1 ♀, 1 juvenile, Lukovska Cave, village Lukovo, Čestobrodica , bear Boljevac, 05.03.2016, D. Antić leg. ; 4 ♀♀, Sesalačka Cave, village Sesalac , near Sokobanja, 18.05.2012, D. Antić, S. Makarov, B. Ilić leg. ; 2 ♀♀, Manastirska Cave, village Minićevo , near Zaječar, 04. VI.2016, D. Antić leg. ; 10 ♀♀, 2 juveniles, village Rsovci, Stara Planina Mt. , near Pirot; 02.10.2002 ; 2 ♀♀, Vodena Cave, left side of the Panjica River, village Brekovo , near Arilje, 17.08.2000 ; 3 ♀♀, Visoka , Arilje, 17.08.2000 ; 1 ♀, village Ljubiš, Zlatibor Mt. , 31.07.2007 ; 1 ♀, Golijska reka, Golija Mt. , near Ivanjica, 24.05.2018, D. Antić, S. Makarov, H. Enghoff leg.

Remarks. These females resemble T. costata and show low, poorly developed posterior ridges on the tergites. Considering that these females were found both in the Carpathian-Balkan and in the Dinaric region in Serbia ( Fig. 12B ), as well as that three species living in Serbia whose females have a similar habitus, viz., T. costata , T. corcyraea and T. similicostata , we leave these samples without closer identification.

Trachysphaera sp. (“ schmidtii ” habitus)

Material examined. Serbia ( IZB): 1 ♀, Radovanska Cave, village Jablanica , near Boljevac, 03.06.2016 ; 1 ♀, vil- lage of Sastavci , near Ivanjica; 08.1998 ; 1 ♀, village Gleđica, Golija Mt. , near Ivanjica, 24.05.2018, D. Antić, S . Makarov, H. Enghoff leg.

Remarks. These females resemble T. schmidtii and show high posterior ridges on the tergites. Considering that three species similar in habitus occur in Serbia, viz., T. cristangula , T. lobotarsus and T. schmidtii , and in the absence of males, we leave these samples without closer identification ( Fig. 12B ).

Figures

FIGURE 1. Trachysphaera species in situ, Serbia (IZB). A–C. T. cristangula (Attems, 1943) from Mucina voda, near Ivanjica (A, B—♂, C—♀). D, E. T. lobotarsus (Attems, 1943) from Medvednik Mt. (D—♂, E—♂ and ♀). F, G. T. schmidtii Heller, 1858 (F—specimens from Avala Mt., G—♀ from Stražilovo, Fruška gora Mt.). H, I. T. similicostata (Radu & Ceuca, 1951) from Stara Planina Mt. (H—specimen from near Ponor, Dojkinci village, I—specimens from no-name cave I, Temska village). All pictures by Dragan Antić, except for G by Dragiša Savić.

FIGURE 11. Trachysphaera similicostata (Radu & Ceuca, 1951), ♂♂ from Serbia (IZB). A–D, H. From no-name cave, village Bela, Pirot. E, G. From Suvodolska Cave. F, I. From Držinska Cave. J–L. From no-name cave II, village Temska, Pirot. A, B. Habitus, dorsal and lateral views, respectively. C. Leg-pair 17, anterior view. D–F. Right leg 18, anterior views. G, H. Telopods, anterior views. I. Syncoxite, anterior view. J–L. Syncoxite, anterodistal, semi-anterior and anteroproximal views, respectively. Scale bars: 1 mm (A, B) and 0.2 mm (C–L).

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