Research Article |
Corresponding author: Dragan Antić ( dragan.antic@bio.bg.ac.rs ) Academic editor: Levan Mumladze
© 2024 Dragan Antić, Tamara Aleksić, Jelena Milovanović, Mert Elverici.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Antić D, Aleksić T, Milovanović J, Elverici M (2024) Rediscovery of Euxinopetalum dobatorum Hoffman, 1973 (Diplopoda, Callipodida, Schizopetalidae) in Turkey. Caucasiana 3: 223-234. https://doi.org/10.3897/caucasiana.3.e137308
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A remarkable dwarf schizopetalid, Euxinopetalum dobatorum Hoffman, 1973, is rediscovered in the Heracles Cave (type locality) in Turkey. This poorly known species is recorded after more than 50 years and is illustrated here with photographs, photomicrographs, and scanning electron micrographs, including descriptive notes and remarks. The small body size and the reduced number of body segments in Callipodida are briefly discussed, while the question about the type locality is clarified.
Anatolia, biospeleology, Black Sea, cave, Euxinopetalinae, millipedes
The millipede fauna of Turkey is still poorly known, although it has been studied by various authors over the last century. So far, just about 140 species are known from the region (
One of the very interesting taxa from Turkey is undoubtedly a tiny schizopetalid Euxinopetalum dobatorum Hoffman, 1973. The small size, reduced number of body segments, undivided hypoproct, characteristics of gonopods, and the presence of the rudimentary leg pair 2 in females make this species very particular within the family Schizopetalidae. For this reason,
Euxinopetalum dobatorum
is only known from the original description, based on a male and a female from two caves in the Zonguldak Province (
Specimens preserved in 70% ethanol were examined with a Nikon SMZ745T, a Nikon SMZ1270, and a Zeiss Stemi 2000-C binocular stereo microscopes (IZB). Pictures of the habitual structures were taken using a Nikon DS-Fi2 camera with a Nikon DS-L3 camera controller attached to a Nikon SMZ1270 binocular stereo microscope (IZB). The gonopods were dissected and mounted in glycerin for temporary microscope preparations and observed with a Carl Zeiss Axioscope 40 microscope (IZB). Pictures of the gonopods were taken with a Canon PowerShot A80 digital camera connected to a Carl Zeiss Axioscope 40 microscope (IZB). For some images, focal stacking was completed with Zerene Stacker Professional v1.04. Drawings of the gonopods were obtained using tracing paper placed on a computer monitor displaying the pictures of those structures made in a previously described way. Pictures of live animals by M.E. were taken with a Nikon D7000 camera with a Nikon AF-S VR Micro Nikkor 105mm f/2.8G IF ED lens. For scanning electron microscopy (SEM), samples were dehydrated in an ascending alcohol series (80%, 90%, 96% EtOH for 10–15 min each), then acetone and air dried. The samples were mounted on aluminum stubs equipped with sticky aluminum tape, coated with platinum (Leica EM SCD500), and studied with a JEOL JSM 6610-LV scanning electron microscope at an accelerating voltage of 15 kV (NHMW). After the SEM examination, all parts were placed back in ethanol. The final images were processed and assembled with Adobe Photoshop CS.
c – coxa;
cp – coxal process;
dl – digitiform rounded lobe;
l – lamella;
mp – medial process;
s – solenomere;
t – telopodite;
tp – trifurcated mesal process;
ABBM – Biodiversity Science Museum, Atatürk University, Erzurum, Turkey;
IZB – Institute of Zoology, University of Belgrade – Faculty of Biology, Belgrade, Serbia;
NHMW – Naturhistorisches Museum Wien, Vienna, Austria.
Order Callipodida Pocock, 1894
Family Schizopetalidae Verhoeff, 1909
Euxinopetalum dobatorum Hoffman, 1973, by original designation.
Differs from all other genera of the family Schizopetalidae by the presence of the rudimentary leg pair 2 in the females (vs leg pair 2 normal in other genera). It also differs from all other Schizopetalidae genera, with the exception of the genus Himatiopetalum Verhoeff, 1900, by the presence of an undivided hypoproct (vs hypoproct divided into three subsclerites in other genera).
In addition, this is one of the smallest callipodids, with a length of 13–15 mm in males and 15.5–23 mm in females, and with the lowest known number of segments recorded in the order, 36 and 38 in adults. Gonopods relatively simple, without sternal remnants; telopodites attached to coxa posteriorly, main stem columnar, simple and straight, distally with several processes; coxal process simple and sigmoid.
Euxinopetalum dobatorum
Hoffman, 1973: 86, figs 1–4;
TURKEY • 3 males, 1 female; Zonguldak Province, Ereğli District, Herakles Cave (= “Höhle 2 bei Ereğli”, = “Cave Nr. 2, Indere, 2 km northwest of Ereğli”), part of Cehennem Ağzı Caves; N41.291725, E31.411989; 35 m a.s.l.; 18 Aug. 2020; leg. M. Elverici; ABBM (1 male, 1 female), IZB (1 male), NHMW MY10517 (1 male).
As for the genus.
Living animals brownish-grey (Fig.
Gonopods (Figs
This is apparently a troglophilic taxon. So far, it is known from two caves in the Zonguldak Province on the western Black Sea coast in Turkey. The original description contains no additional data for the two given localities. The type locality, Heracles Cave (see also discussion), is part of three closely located tourist caves or caverns with archeological significance, referred to as “Hell’s Mouth Caves” in direct translation from Turkish (= Cehennemağzı Mağaraları). These caves are linked to Greek mythology, in particular with the story of Hercules (Heracles) and his descent into the Underworld. According to mythology, this is where Hercules entered Hades to capture Cerberus, the three-headed guard dog of the Underworld, as part of his Twelfth Labour (
The main gallery of this tourist cave is severely transformed and illuminated. The new specimens were discovered in a fossil, narrow lateral passage that falls under the complete provision of the dark zone (Fig.
The examination of recently collected specimens, consisting of three males and one female, generally agrees with the description of
To avoid confusion, the telopodite is attached to the posterior side of the coxa.
Euxinopetalum dobatorum Hoffman, 1973 habitus. A: male (ABBM), habitus, lateral view; B: female (ABBM), telson, ventral view; C: male (ABBM), anterior part of body, lateral view; D: male (IZB), anterior part of body, dorsal view; E: male (IZB), head, anterior view; F: male (NHMW MY10517), midbody segments, dorsolateral view; G: female (ABBM), anterior part of body, anterior and ventral view; H: female (ABBM), body segments 22–25, dorsal view. White arrows indicate ozopores. Scale bars = 1 mm (A), 0.5 mm (B–H).
Euxinopetalum dobatorum Hoffman, 1973 male (IZB), gonopods. A: anterior view; B: distal part of right telopodite, anterior view; C: posterodistal view; D: distal part of left telopodite, posterodistal view; E: distal part of right telopodite, anterodistal view; F: distal part of left telopodite, anterior view; G: right telopodite and distal part of right coxal process, mesal view; H: lateral view. Abbreviations = c-coxa; cp-coxal process; dl-digitiform rounded lobe; l-lamella; mp-medial process; s-solenomere; t-telopodite; tp-trifurcated mesal process. Scale bars = 0.1 (A, C), 0.05 mm (B, D, E–H).
Most species of the order Callipodida are characterized by a medium-sized to large body. The largest representatives of this group come from the family Schizopetalidae, where some species from the genera Eurygyrus C.L. Koch, 1847, and Apfelbeckia Verhoeff, 1896 can grow 10 cm or more (
The distribution of E. dobatorum is, as we know, restricted to the western Black Sea coast of Turkey and the Zonguldak Province. In the original description
As
DA is grateful to Nesrine Akkari for her hospitality and great time during his visit to NHMW in July 2024 and to Wencke Wegner for the help during the SEM imaging. Gökhan Eren Çankaya and Ertuğrul Kulaksızoğlu contributed to the field study at the planning and caving stages within the body of Kaşif Consulting, Reporting, Organization Company. The cave plan was originally drawn by Barış Kaymaz, prior to being edited for this paper by ME. Bülent Erdem provided invaluable comments for determining the identities of caves in the literature records. We would like to thank the reviewers Nesrine Akkari and Pavel Stoev for their suggestions and corrections that improved the manuscript, and the editor Levan Mumladze for taking care of this manuscript.
The authors have declared that no competing interests exist.
No ethical statement was reported.
This study was partly supported by the Ministry of Science, Technological Development and Innovation of the Republic of Serbia (451-03-65/2024-03/200178). DA's visit to the NHMW in July 2024 was financed by himself. The General Directorate of Conservation of Natural Assets, Ministry of Environment, Urbanisation and Climate Change of the Republic of Turkey supported the field study.
DA initiated this study, took SEM photographs, made figure plates and wrote the first draft of the paper and together with TA and JM made photomicrographs, drawings and descriptive notes. ME collected the specimens, took in situ photographs and provided the collection site information. TA, JM and ME revised the final version of the manuscript.
Dragan Antić https://orcid.org/0000-0002-1231-4213
Tamara Aleksić https://orcid.org/0009-0009-7585-0900
Jelena Milovanović https://orcid.org/0000-0002-8096-6870
Mert Elverici https://orcid.org/0000-0003-3233-9968
All of the data that support the findings of this study are available in the main text or Supplementary Information.