Print
Diversity and distribution of the millipedes (Diplopoda) of Georgia, Caucasus
expand article infoMzia S. Kokhia, Sergei I. Golovatch§
‡ Ilia State University, Tbilisi, Georgia
§ Institute for Problems of Ecology and Evolution, Russian Academy of Sciences, Moscow, Russia
Open Access

Abstract

The diplopod fauna of Georgia, Transcaucasia, is very rich given the country’s relatively small territory; it presently comprises 103 species from 44 genera, 12 families, and 7 orders. Most of the Diplopoda known from Georgia (86 species, or 83%) demonstrate Caucasian distribution patterns, 36 and 46 species, as well as 8 and 9 genera being endemic or subendemic to the country, respectively. A single Holarctic family, Anthroleucosomatidae (order Chordeumatida), contains 44 Caucasian species and 20 genera, of which 27 species and 14 genera are endemic or subendemic to Georgia. Likewise, all species from the orders Polyzoniida, Siphonocryptida, Glomerida and Chordeumatida, as well as most species of Julida and Polydesmida are native, also endemic or subendemic to the Caucasus, but the genera and families they represent are widely distributed at least across the Euro-Mediterranean Realm. Most of the presumed troglobionts in the Caucasus appear to be confined to western Georgia’s karst caves (14 species, 5 genera). Within Georgia, the fauna of the western part (= Colchis) is particularly rich and diverse, while that of the central and eastern parts of the country grows increasingly depauperate inland following the gradual climatic aridisation from west (Black Sea coast) to east (Armenia and Azerbaijan). The vertical distribution of the Diplopoda in Georgia, as well as the Caucasus generally, shows the bulk of the fauna restricted to forested lowland to mountain biomes or their remnants. Only very few Chordeumatida and Julus species seem to occur solely in the subalpine to alpine environments and thus may provisionally be considered as high-montane elements. Ongoing and future research on the millipedes of the Caucasus, especially in cave and montane environments, will undoubtedly allow for many more novelties and details of the diversity and distribution of Georgia’s Diplopoda to be revealed or refined.

Keywords

checklist, Colchis, endemism, fauna, Myriapoda

Introduction

Georgia is one of the main countries in the Caucasus, lying between western Asia and Eastern Europe. It is bounded in the west by the Black Sea, in the north by Russia, in the south by Turkey, and in the southeast and east by Armenia and Azerbaijan (Fig. 1). The area is mainly montane to high montane, situated between 41° and 44°N, and 40° and 47°E. The Greater Caucasus Mountain Range, or Caucasus Major, forms the northern border of Georgia, while the southern border is bounded by the Lesser Caucasus Mountains, or Caucasus Minor. The Caucasus Major is much higher in elevation (more than 5000 m a.s.l.) than the plateau-like Caucasus Minor, both being connected by the submeridional Surami (= Likhi) Mountain Range which divides Georgia into the western and central + eastern parts. Both parts are quite varied in climate and biota. Western Georgia’s landscape ranges from lowland marsh-forests, swamps, and temperate rainforests within the Colchis Plain to eternal snows and glaciers, while the eastern part of the country even contains a small segment of semi-arid plains. Forests cover around 40% of Georgia’s territory, while the alpine/subalpine zone accounts for approximately 10% of the land. The climate of Georgia is extremely diverse, considering the nation’s small size, but is largely mild to warm. There are two main climatic zones, roughly corresponding to the eastern and western parts of the country. The Greater Caucasus Mountain Range plays an important role in moderating Georgia’s climate and protects the nation from the penetration of colder air masses from the north. The Lesser Caucasus Mountains partially protect the region from the influence of dry and hot air masses from the south (Bondyrev et al. 2015).

Figure 1. 

Geographic division of Georgia.

The millipede fauna of Georgia has recently been reviewed and shown to comprise 95 species from 42 genera, 12 families, and 7 orders (Kokhia and Golovatch 2018). A few relevant faunistic papers have, or will have, appeared since (Golovatch 2018, Golovatch and Turbanov 2017, Antić et al. 2018, Evsyukov et al. 2018, 2020, Vagalinski and Lazányi 2018, Short et al. 2020), allowing for the previous checklist to be rectified and updated, as well as the previous reference list to be considerably shortened. The present checklist contains 103 species from 44 genera, 12 families, and 7 orders (Table 1). Data on the elevations at which the species occur, both within and beyond Georgia, are also added, representing the basic information for our analysis of millipede vertical distributions.

Material and methods

Only described species and published records are considered in our paper, while dubious taxa and those not identified to the species level have been omitted both from the checklist and reference list. Only one important exception has been made: Calyptophyllum sp. as the only record of this genus in the Caucasus (Table 1).

Three zigzag transects chosen to grossly reflect the north-to-south lie of the macro relief of Georgia, extending from the Caucasus Major in the north to the Caucasus Minor in the south (Figs 25), have been drawn, one each for the western, central and eastern parts of the country (Fig. 1). The transect across western Georgia connects Pitsunda – Arabika Plateau – Khaishi – Bagdati – Batumi (427 km long), that in central Georgia connects Roki Tunnel – Tskhinvali – Tbilisi – Tsalka Reservoir – Ninotsminda – Javakheti National Park (275 km), and the eastern Georgia one connects Omalo – Tianeti – Akhmeta – Shilda – Kvareli – Lagodekhi – Tamariani (186 km) (Fig. 2). Both at the bottom of the maps and on the maps themselves, each transect is accompanied by the respective altitudes given for each of the turn localities and thus provides a clear generalized picture of the macro relief (Figs 35). These three transects thus cover all major variations in millipede vertical distribution across entire Georgia. This novel approach to a graphic presentation of faunistic results allows us to combine the horizontal and vertical distributions of millipedes in the easiest and most vivid way on the same map. Mapping largely concerns endemic or subendemic species and concerns only the territory of Georgia.

Most of the colour maps were generated using Google Earth Pro version 7.3.2.5495 and Adobe Photoshop CS6. The final images were processed with Adobe Photoshop CS6.

Results

The diplopod fauna of the Caucasus region, including Georgia, is basically Euro-Mediterranean in its composition (Table 1). This also concerns the relatively few widespread, likely introduced species from the orders Polyxenida, Julida and Polydesmida that occur in the Caucasus. Even among the few unquestioned introductions, only Oxidus gracilis (C.L. Koch, 1847) is an Oriental or East Asian alien element.

A revised checklist of the Diplopoda of Georgia, with data on species distributions, both within and beyond the country, their statuses, and the main relevant literature sources. Designations: i – introduced; G – entire Georgia; W – western Georgia; C – central Georgia; E – eastern Georgia; R – Russian Caucasus; T – Turkey; Ar – Armenia; Az – Azerbaijan; Cr – Crimean Peninsula; (+) – present; e – endemic to Georgia; se – subendemic to Georgia; t – presumed troglobiont; sc – subcosmopolitan; EuM – Euro-Mediterranean; M – Mediterranean; EM – eastern Mediterranean; EE – eastern European; Ca – Caucasian.

Fauna G R T Ar Az Cr Elevations (m a.s.l.) and status Distribution pattern Main relevant references
Class Diplopoda
Order Polyxenida
Family Polyxenidae
Genus Polyxenus Latreille, 1803
1. Polyxenus lagurus (Linnaeus, 1758) W + + 20–1700, i sc Issaev 1911, Short et al. 2020
2. Polyxenus lankaranensis Short, Vahtera, Wesener & Golovatch, 2020 E + + 100–800 Ca Short et al. 2020
Genus Propolyxenus Silvestri, 1948 W
3. Propolyxenus argentifer (Verhoeff, 1921) G + + + + + 20–1700 EM Short et al. 2020
Family Lophoproctidae
Genus Lophoproctus Pocock, 1894
4. Lophoproctus coecus Pocock, 1894 G + 20–900 EM Short 2015, Short et al. 2020
Order Polyzoniida
Family Hirudisomatidae
Genus Hirudisoma Fanzago, 1881
5. Hirudisoma roseum (Victor, 1839) G + + + 20–1100, se EM Golovatch et al. 2015
Order Siphonocryptida
Family Siphonocryptidae
Hirudicryptus Enghoff & Golovatch, 1985
6. Hirudicryptus abchasicus Golovatch, Evsyukov & Reip, 2015 W + 600–1500, se Ca Golovatch et al. 2015, Zuev 2017
Order Glomerida
Family Glomeridae
Genus Hyleoglomeris Verhoeff, 1910
7. Hyleoglomeris awchasica (Brandt, 1840) W + 20–2100, se Ca Golovatch 1975, 1976a, 1989b
8. H. specialis Golovatch, 1989 E + 500–1400, se Ca Golovatch 1989b
Genus Trachysphaera Heller, 1858
9. Trachyspaera costata (Waga, 1857) G + + + + + 20–2000 EuM Golovatch 1990, 2008
10. T. fragilis Golovatch, 1976 G + 80–460, t, e Ca Golovatch 1976c,1990, Golovatch and Turbanov 2017
11. T. minuta Golovatch, 1976 G + + + 20–1700, se Ca Golovatch 1976c, 1990
12. T. orientalis Golovatch, 1976 W 800–1100, t, e Ca Golovatch 1976c, 1990
13. T. radiosa (Lignau, 1911) W + 20–1800, se Ca Golovatch 1976a, 1990
14. T. solida Golovatch, 1976 W, C 20–2020, se Ca Golovatch 1976c, 1976c, 1990, 1993
Family Glomeridellidae
Genus Typhloglomeris Verhoeff, 1898
15. Typhloglomeris lohmanderi (Golovatch, 1989) C, E + + 600–1450, se Ca Golovatch 1989a, 2003
16. Typhloglomeris palatovi Golovatch & Turbanov, 2018 W 650, t, e Ca Golovatch and Turbanov 2017
Order Chordeumatida
Family Anthroleucosomatidae
Genus Acanthophorella Antić & Makarov, 2016
17. Acanthophorella barjadzei Antić & Makarov, 2016 W 1120–1200, t, e Ca Antić and Makarov 2016
Genus Adshardicus Golovatch, 1981
18. Adshardicus strasseri Golovatch, 1981 W + 20–530, se Ca Enghoff 2006, Antić and Makarov 2016
Genus Alpinella Antić & Makarov, 2016
19. Alpinella waltheri Antić & Makarov, 2016 E 2860, e Ca Antić and Makarov 2016
Genus Brachychaetosoma Antić & Makarov, 2016
20. Brachychaetosoma turbanovi Antić & Makarov, 2016 W 300, t, e Ca Antić and Makarov 2016
Genus Caucaseuma Strasser, 1970
21. Caucaseuma kelasuri Antić & Makarov, 2016 W 190, e Ca Antić and Makarov 2016
22. C. variabile Antić & Makarov, 2016 C + 100–2500, se Ca Antić and Makarov 2016
Genus Cryptacanthophorella Antić & Makarov, 2016
23. Cryptacanthophorella manubriata Antić & Makarov, 2016 W, C 800–1700, e Ca Antić and Makarov 2016
Genus Dentatosoma Antić & Makarov, 2016
24. Dentatosoma denticulatum Antić & Makarov, 2016 W 400–900, e Ca Antić and Makarov 2016
25. D. magnum Antić & Makarov, 2016 W + 20–2200, se Ca Antić and Makarov 2016
26. D. zeraboseli Antić & Makarov, 2016 W 20–1700, e Ca Antić and Makarov 2016
Genus Georgiosoma Antić & Makarov, 2016
27. Georgiosoma bicornutum Antić & Makarov, 2016 W 2000, t, e Ca Antić and Makarov 2016
Genus Herculina Antić & Makarov, 2016
28. Herculina oligosagittae Antić & Makarov, 2016 W 1500–1700, e Ca Antić and Makarov 2016
29. H. polysagittae Antić & Makarov, 2016 C 1750, e Ca Antić and Makarov 2016
Genus Heterocaucaseuma Antić & Makarov, 2016
30. Heterocaucaseuma deprofundum Antić & Makarov, 2018 W 2000–2100, t, e Ca Antić et al. 2018
31. H. longicorne Antić & Makarov, 2016 W 100–350, t, e Ca Antić and Makarov 2016, Antić et al. 2018
32. H. mauriesi (Golovatch & Makarov, 2011) W 215, t, e Ca Golovatch and Makarov 2011, Antić and Makarov 2016, Antić et al. 2018
Genus Metamastigophorophyllon Ceuca, 1976
33. Metamastigophorophyllon giljarovi (Lang, 1959) W + 20–1850, se Ca Antić and Makarov 2016
34. M. hamatum Antić & Makarov, 2016 W + 150–2200, se Ca Antić and Makarov 2016
35. M. lamellohirsutum Antić & Makarov, 2016 W 700–800, e Ca Antić and Makarov 2016
36. M. torsivum Antić & Makarov, 2016 G + 800–1700, se Ca Antić and Makarov 2016
Genus Paranotosoma Antić & Makarov, 2016
37. Paranotosoma attemsi Antić & Makarov, 2016 W 1500–1800, e Ca Antić and Makarov 2016
38. P. cordatum Antić & Makarov, 2016 W 20–800, e Ca Antić and Makarov 2016
39. P. subrotundatum Antić & Makarov, 2016 W, C + 350–850, se Ca Antić and Makarov 2016
Genus Pseudoflagellophorella Antić & Makarov, 2016
40. Pseudoflagellophorella eskovi Antić & Makarov, 2016 C, E + + 100–2080, se Ca Antić and Makarov 2016
41. P. mirabilis Antić & Makarov, 2016 W 20–130, e Ca Antić and Makarov 2016
42. P. papilioformis Antić & Makarov, 2016 E + 850–2100, se Ca Antić and Makarov 2016
Genus Ratcheuma Golovatch, 1985
43. Ratcheuma excorne Golovatch, 1985 W 1180, t, e Ca Golovatch 1984/85, Antić and Makarov 2016
Order Julida
Family Blaniulidae
Genus Cibiniulus Verhoeff, 1927
44. Cibiniulus phlepsii (Verhoeff, 1897) W + 20–130 EuM Enghoff 1984, 2006
Genus Nopoiulus Menge, 1851
45. Nopoiulus brevipilosus Enghoff, 1984 W 130, t, e Ca Enghoff 1984, Golovatch and Enghoff 1990
46. N. densepilosus Enghoff, 1984 W + + 1500–1700 Ca Enghoff 1984, Golovatch and Enghoff 1990
47. N. golovatchi Enghoff, 1984 W + 20–130, se Ca Enghoff 1984, 1990
48. N. kochii (Gervais, 1847) G + + + + 10–2200, i? sc Enghoff 1984, Golovatch and Enghoff 1990
Family Nemasomatidae
Genus Nemasoma C.L. Koch, 1847
49. Nemasoma caucasicum (Lohmander, 1932) G + + + + 20–2000, se Ca Kobakhidze 1965, Enghoff 1985
Family Julidae
Genus Archileucogeorgia Lohmander, 1936
50. Archileucogeorgia abchasica Lohmander, 1936 W 130, t, e Ca Lohmander 1936
51. A. satunini Lohmander, 1936 W 130, e Ca Lohmander 1936
Genus Brachyiulus Berlese, 1884
52. Brachyiulus lusitanus Verhoeff, 1898` C + 100, i M Lohmander 1936
Genus Byzantorhopalum Verhoeff, 1930
53. Byzantorhopalum rossicum (Timotheew, 1897) W? + + + 30–1500 EE Lohmander 1936, Vagalinski and Lazányi 2018
Genus Catamicrophyllum Verhoeff, 1900
54. Catamicrophyllum caucasicum (Attems, 1901) G + + + 700–2000, se Ca Lohmander 1936, Enghoff 1995
Genus Calyptophyllum Brolemann, 1922
55. Calyptophyllum sp. W 100? ? Lohmander 1936, Enghoff 1995
Genus Chaetoleptophyllum Verhoeff, 1898
56. Chaetoleptophyllum flexum Golovatch, 1979 G + 15–2200, se Ca Golovatch 1979, Evsyukov et al. (2020)
Genus Cylindroiulus Verhoeff, 1894
57. Cylindroiulus bellus (Lignau, 1903) W? + + 100 EM Lignau 1903, Read 1992, Chumachenko 2016
58. C. crassiphylacum Read, 1992 W, C + 600–1700, se Ca Read 1992
59. C. kacheticus Lohmander, 1936 E + 500–1250, se Ca Lohmander 1936, Read 1992
60. C. olgainna Read, 1992 W 300–1100, e Ca Read 1992
61. C. parvus Lohmander, 1928 C, E + 500–2100, se Ca Lohmander 1936, Read 1992
62. C. placidus (Lignau, 1903) W, C + 20–2200, se Ca Lignau 1903, Read 1992
63. C. pterophylacum Read, 1992 W, C + 20–1600, se Ca Read 1992, Zuev 2014
64. C. quadrus Read, 1992 W, C 700–1000, e Ca Read 1992
65. C. ruber (Lignau, 1903) W + 100–2000, se Ca Lignau 1903, 1915, Read 1992
66. C. schestoperovi Lohmander, 1936 W + 400–1800, se Ca Lohmander 1936, Read 1992
67. C. truncorum (Silvestri, 1896) W + + 130, i sc Read 1992
Genus Grusiniulus Lohmander, 1936
68. Grusiniulus redikorzevi Lohmander, 1936 C 800–900, e Ca Lohmander 1936, Vagalinski and Lazányi 2018
Genus Julus Linnaeus, 1758
69. Julus colchicus Lohmander, 1936 G + + 20–2850, se Ca Lohmander 1936, Enghoff 2006, Evsyukov et al. 2018
70. J. kubanus Lohmander, 1936 W, E + 300–2100, se Ca Lohmander 1936, Kobakhidze 1965, Evsyukov et al. 2018
71. J. lignaui Verhoeff, 1910 W + 1500–2800, se Ca Evsyukov et al. 2018
72. J. lindholmi Lohmander, 1936 W + 450–2200, se Ca Lohmander 1936, Evsyukov et al. 2018
Genus Kubaniulus Lohmander, 1936
73. Kubaniulus gracilis Lohmander, 1936 W + 20–700, se Ca Lohmander 1936, Evsyukov et al. 2020
Genus Leptoiulus Verhoeff, 1894
74. Leptoiulus hastatus Lohmander, 1932 C + 800–1530, se Ca Lohmander 1936, Enghoff 2006, Evsyukov et al. 2020
75. L. tanymorphus (Attems, 1901) C, E + + + 80–1800, se Ca Lohmander 1936, Evsyukov et al. 2020
Genus Leucogeorgia Verhoeff, 1930
76. Leucogeorgia longipes Verhoeff, 1930 W 170, t, e Ca Verhoeff 1930, Barjadze et al. 2019
77. L. rediviva Golovatch, 1983 W 330, t, e Ca Golovatch 1983, Barjadze et al. 2019
Genus Megaphyllum Verhoeff, 1894
78. Megaphyllum dioscoriadis (Lignau, 1915) W + 130–1400, se Ca Lignau 1915, Lohmander 1936, Kobakhidze 1965, Chumachenko 2016, Vagalinski and Lazányi 2018
79. M. hercules (Verhoeff, 1901) W + 20, i EM Lazányi and Vagalinski 2013
80. M. spathulatum (Lohmander, 1936) W? ? ? Ca Lohmander 1936, Lazányi and Vagalinski 2013
Genus Omobrachyiulus Lohmander, 1936
81. Omobrachyiulus adsharicus (Lohmander, 1936) W 20–30, e Ca Lohmander 1936, Vagalinski and Lazányi 2018
82. O. brachyurus (Attems, 1899) G + + + + 20–2500 EM Lohmander 1936, Kobakhidze 1965, Enghoff 2006, Vagalinski and Lazányi 2018
83. O. curvocaudatus (Lignau, 1903) W + 30–1700, se Ca Lohmander 1936, Kobakhidze 1965, Vagalinski and Lazányi 2018
84. O. divaricatus (Lohmander, 1936) G + 600 –2000, se Ca Lohmander 1936, Kobakhidze 1965, Vagalinski and Lazányi 2018
85. O. hortensis (Golovatch, 1981) W 150, e Ca Golovatch 1981, Vagalinski and Lazányi 2018
86. O. implicitus Lohmander, 1936 (= O. i. ritsensis (Golovatch, 1981)) W + 400–1800, se Ca Lohmander 1936, Chumachenko 2016, Vagalinski and Lazányi 2018, Vagalinski in litt.
87. O. macrourus (Lohmander, 1928) (= O. m. abchasicus (Lohmander, 1936)) W, C 130–2000, e Ca Lohmander 1936, Kobakhidze 1965, Vagalinski and Lazányi 2018, Vagalinski in litt.
Genus Pachyiulus Berlese, 1883
88. Pachyiulus flavipes (C.L. Koch, 1847) W + 30, i M Lohmander 1936
89. P. krivolutskyi Golovatch, 1977 W + 20–1800, se Ca Golovatch 1977, Evsyukov 2016
Genus Syrioiulus Verhoeff, 1914
90. Syrioiulus adsharicus (Lohmander, 1936) W 120, e Ca Lohmander 1936, Golovatch 2018
91. S. georgicus (Lohmander, 1932) C 800–900, e Ca Lohmander 1932, Golovatch 2018
Order Polydesmida
Family Paradoxosomatidae
Genus Oxidus Cook, 1911
92. Oxidus gracilis (C.L. Koch, 1847) W + 20–100, i Ca Lignau 1915, Lohmander 1936, Chumachenko 2016
Genus Strongylosoma Brandt, 1833
93. Strongylosoma kordylamythrum Attems, 1898 G + + 20–2200 Ca Lohmander 1936, Kobakhidze 1965, Evyukov et al. 2016
94. S. lenkoranum Attems, 1898 C + + + 80–1650 Ca Lohmander 1936, Kobakhidze 1965, Evyukov et al. 2016
Family Polydesmidae
Genus Brachydesmus Heller, 1858
95. Brachydesmus assimilis Lohmander, 1936 C, E + + + 600–2800, se Ca Golovatch et al. 2016
96. B. furcatus Lohmander, 1936 W + 20–1900, se Ca Golovatch et al. 2016
97. B. kalischewskyi Lignau, 1915 G + + + + 50–2400, se Ca Golovatch et al. 2016
98. B. kvavadzei Golovatch, Evsyukov & Reip, 2016 W 70–1520, e Ca Golovatch et al. 2016
99. B. simplex Golovatch, Evsyukov & Reip, 2016 W + 20–1100, se Ca Golovatch et al. 2016
100. B. superus Latzel, 1884 W + 150–450, i sc Golovatch et al. 2016
Genus Polydesmus Latreille, 1803
101. Polydesmus abchasius Attems, 1899 W, C + 10–2230, se Ca Golovatch et al. 2016
102. P. lignaui Lohmander, 1936 W + 100–2200, se Ca Golovatch et al. 2016
103. P. mediterraneus Daday, 1889 W + 100, i EM Golovatch et al. 2016

All species of Polyzoniida, Siphonocryptida, Glomerida and Chordeumatida, as well as most species of Julida and Polydesmida appear to be native, endemic or subendemic, but the genera and families they represent are widely distributed across the Euro-Mediterranean Realm. As a result, endemism is profound at the species and, to a lesser degree, generic levels. Most of the species (86, or 83%) show a Caucasian distribution pattern, thus being endemic or subendemic to the Caucasus region. The same pattern was found at the generic level, with 18 genera being endemic or subendemic to the Caucasus, including all 14 genera of the order Chordeumatida that inhabit the region (Antić and Makarov 2016, Antić et al. 2018). There are neither families nor orders of Diplopoda that are confined to the Caucasus region alone.

Our analysis of the distribution of Georgia’s millipedes is largely based on strictly endemic and subendemic species (36 and 46, respectively: Table 1) and genera (8 and 9, respectively: Alpinella, Brachychaetosoma, Cryptacanthophorella, Georgiosoma, Grusiniulus. Herculina, Leucogeorgia and Ratcheuma, vs. Adshardicus, Acanthophorella, Archileucogeorgia, Caucaseuma, Dentatosoma, Heterocaucaseuma, Omobrachyiulus, Paranotosoma and Pseudoflagellophorella). It shows that western Georgia, including Abkhazia and Ajaria – which are shown separately (Figs 9, 10) to more clearly depict the localities/distributions and thus to avoid an “overcrowded” picture – supports the richest and most diverse fauna (Figs 710). This is also the area where all 14 presumed troglobionts are found in Georgia, all confined to karst caves (Barjadze et al. 2019). Abkhazia, northwestern Georgia, is the richest subregion both in epigean and troglobitic Diplopoda (Figs 79), hosting, among others, Heterocaucaseuma deprofundum Antić & Makarov, 2018. This species is the world’s deepest record of a millipede, found at 60–1980 m below the surface in the Krubera-Voronja and Sarma caves, Arabika Massif, Abkhazia (Fig. 3). Both these caves are among the deepest globally and support the second and third deepest subterranean invertebrate communities, respectively. Furthermore, both harbour still one more diplopod species, a yet undescribed Leucogeorgia sp. (Antić et al. 2018).

This picture is hardly surprising, as due to the proximity to the Black Sea the climate of western Georgia is largely humid warm temperate. More easterly, the climate is increasingly dry and hot, already dominating eastern Georgia (Bondyrev et al. 2015). Following this trend, the millipede fauna is increasingly depauperate: at least 79 diplopod species occur in western Georgia (= Colchis), but this number drops down to 37 in the central and to 25 in the eastern parts of Georgia (Table 1, Figs 712). Millipedes are mainly confined to forests in the Caucasus and in Georgia reflecting their terrestrial, meso- to hygrophilous, largely also calciphilous, arthropod relationships which are historically, trophically and ecologically closely associated with forested biomes (Golovatch and Kime 2009). Dry steppes and arid light forests in central and eastern Georgia (Table 2), as well as the Colchidan swamps of western Georgia support only very few millipede species. Especially tolerant to xeric conditions seems to be Leptoiulus tanymorphus (Attems, 1901) (Fig. 12), whereas both Hirudisoma roseum (Victor, 1839) and Julus colchicus Lohmander, 1936 (Fig. 6), as well as several Chordeumatida tend to represent particularly hydrophilous epigean species. Nearly all cavernicoles (e.g., Leucogeorgia spp.) are likewise highly hydrophilous.

As noted above, due to the quite extensive karsts that blanket much of western Georgia, in particular Abkhazia, Samegrelo, Racha Lechkhumi and Imereti, a large proportion of the total fauna is taken up by true cavernicoles (14 species, or 13%). The bulk, however, remains forest-dwelling millipedes and their woody habitats mainly are more or less montane. Present-day Georgia enjoys a remarkable network of nature reserves and national parks, with more than 1/3 of the entire national territory still covered with mountain forests. In contrast, its lowland woodlands have largely been destroyed and long replaced by agri- or sylvicultures, as well as orchards and vineyards (https://apa.gov.ge/en/protected-areas/national-park).

Following Gulisashvili (1964) and Nakhutsrishvili (2013), the altitudinal nature zonation of Georgia can crudely be presented in a tabular form (Table 2). The zonation varies quite clearly in different parts of Georgia (Fig. 1) in relation to climatic gradients. Central Georgia (Figs 1, 4), which is climatically closer to the eastern part of the country, warrants recognition as a separate entity based at least on the distribution of several endemic or subendemic species of Diplopoda (Fig. 11).

No transects are contained in Figures 612 to avoid an “overcrowded” presentation of the numerous species distributions; however, these are easy to extrapolate from the figures and thus to follow the general trends and variations in the macro relief of the corresponding parts of Georgia. Only relatively few millipedes occur in subalpine to alpine environments (usually ≥ 2200 m a.s.l.) in Georgia (Table 2). Yet nearly none of them can be considered as being characteristic of the high altitudes, because the same species appear to populate lower elevations as well, down to almost sea-level: Caucaseuma variabile Antić & Makarov, 2016, Dentatosoma magnum Antić & Makarov, 2016, Metamastigophorophyllon hamatum Antić & Makarov, 2016, Chaetoleptophyllum flexum Golovatch, 1979, Cylindroiulus placidus (Lignau, 1903), Strongylosoma kordylamythrum Attems, 1898, Brachydesmus assimilis Lohmander, 1936, B. kalischewskyi Lignau, 1915, Polydesmus abchasius Attems, 1899 and P. lignaui Lohmander, 1936. The same concerns Omobrachyiulus brachyurus (Attems, 1899) and Catamicrophyllum caucasicum (Attems, 1901), both of which occur also at ≤ 2500 m a.s.l. in the Caucasus Minor of Armenia and Azerbaijan; the former species also in Dagestan, Russia, Caucasus Major (personal observations). Nopoiulus kochii (Gervais, 1847) is a subcosmpolitan species, common also throughout the Caucasus (10–2200 m a.s.l., Table 1), but because the entire genus Nopoiulus is particularly diverse in the Caucasus region, the latter could well have also been the origin centre of N. kochii (Golovatch and Enghoff 1990).

At the present, the only exception that may possibly be referred to as a high-montane element in the fauna of Georgia, as well as the entire Caucasus, seems to be Alpinella waltheri Antić & Makarov, 2016 (2860 m a.s.l., Table 1, Map 12). Even though some species of Julus, i.e., Julus colchicus Lohmander, 1936 (20–2850 m a.s.l.), J. kubanus Lohmander, 1936 (300–2100 m a.s.l.) and J. lindholmi Lohmander, 1936 (450–2200 m a.s.l., Table 1, Figs 9, 12), mostly occur over a wide range of altitudes, J. lignaui Verhoeff, 1910 (1500–2800 m a.s.l.) is perhaps the sole congener that seems to be inclined to dwelling in high-mountain environments. However, the paucity or even absence of unequivocally high-mountain elements in the Caucasus generally, and in Georgia in particular, requires confirmation, as our knowledge of the millipede fauna of the regions concerned is still far from complete.

Figure 2. 

Map of Georgia with three transects (light blue), one each in the western, central and eastern parts of the country, to crudely show both horizontal and vertical distributions of millipedes endemic or subendemic to the country.

Figure 3. 

Map of western Georgia with its transect (light blue), Pitsunda – Arabika Plateau – Khaishi – Bagdati – Batumi, and macro relief (bottom).

Figure 4. 

Map of central Georgia with its transect (light blue), Roki Tunnel – Tskhinvali – Tbilisi – Tsalka Reservoir – Ninotsminda – Javakheti National Park, and its macro relief (bottom).

Vertical zonation of Georgia’s vegetation belts.

Vegetation belts Western Georgia, altitude (m a.s.l.) Eastern Georgia, altitude (m a.s.l.)
deserts, dry steppes and arid light forests 150–600
forests 0–1900 600–1900
subalpine 1900–2500 1900–2500
alpine 2500–3100 2500–3000
subnival and nival 3100–3600 and > 3600 3000–3500 and > 3500
Figure 5. 

Map of eastern Georgia with its transect (light blue), Omalo – Tianeti – Akhmeta – Shilda – Kvareli – Lagodekhi – Tamariani, and its macro relief (bottom).

Figure 6. 

Map showing the distributions of four particularly widespread millipedes endemic or subendemic to Georgia. Designations: yellow ball (Hirudisoma roseum), green ball (Chaetoleptophyllum flexum), pink square (Metamastigophorophyllon torsivum), blue star (Julus colchicus).

Figure 7. 

Map of western Georgia (= Colchis) showing the distributions of some endemic or subendemic species. Designations: orange ball (Hyleoglomeris awchasica), red ball (Nopoiulus golovatchi), green triangle (Cylindroiulus pterophylacum), red ring (Cylindroiulus ruber), white ball (Polydesmus abchasius), blue ball (Trachysphaera fragilis), green star (Trachysphaera radiosa), pink ring (Cylindroiulus schestoperovi), yellow ring (Hirudicryptus abchasicus).

Figure 8. 

Map of western Georgia (= Colchis) showing the distributions of some other endemic or subendemic species. Designations: green diamond (Georgiosoma bicornutum), white ball (Trachysphaera minuta), orange diamond (Trachysphaera orientalis), red ball (Trachysphaera solida), red star (Typhloglomeris palatovi), red ring (Paranotosoma cordatum), blue star (Cylindroiulus quadrus), blue ball (Cylindroiulus placidus) , yellow square (Pachyiulus krivolutskyi), green star (Acanthophorella barjadzei), pink ring (Metamastigophorophyllon lamellohirsutum), blue ring (Paranotosoma attemsi), yellow ring (Ratcheuma excorne), white ring (Nemasoma caucasicum), green ring (Leucogeorgia longipes).

Figure 9. 

Map of Abkhazia showing the distributions of some endemic or subendemic species. Designations: red triangle (Brachychaetosoma turbanovi), blue square (Caucaseuma kelasuri), orange star (Archileucogeorgia abchasica), pink star (Omobrachyiulus implicitus), orange square (Cylindroiulus olgainna), blue ring (Paranotosoma subrotundatum), yellow star (Julus lindholmi), green star (Leucogeorgia rediviva), green ring (Dentatosoma magnum), pink ring (Heterocaucaseuma deprofundum), orange diamond (Metamastigophorophyllon giljarovi), white ring (Kubaniulus gracilis), blue star (Metamastigophorophyllon hamatum), red ring (Pseudoflagellophorella mirabilis), red diamond (Megaphyllum dioscoriadis), yellow square (Nopoiulus brevipilosus), yellow triangle (Archileucogeorgia satunini), orange ball (Heterocaucaseuma longicorne), red ball (Omobrachyiulus hortensis), blue ball (Brachydesmus furcatus), green ball (Brachydesmus simplex), yellow ball (Polydesmus lignaui), green square (Heterocaucaseuma mauriesi).

Figure 10. 

Map of Ajaria showing the distributions of some endemic or subendemic species. Designations: blue ball (Adshardicus strasseri), red diamond (Brachydesmus kvavadzei), green ball (Dentatosoma denticulatum), orange star (Dentatosoma zeraboseli), yellow square (Omobrachyiulus adsharicus), white triangle (Omobrachyiulus divaricatus), yellow ball (Paranotosoma cordatum), yellow triangle (Syrioiulus adsharicus).

Figure 11. 

Map of central Georgia showing the distributions of some endemic or subendemic species. Designations: blue ring (Brachydesmus kalischewskyi), yellow ring (Caucaseuma variable), green Ring (Catamicrophyllum caucasicum), red ball (Cylindroiulus crassiphylacum), orange ring (Cylindroiulus pterophylacum), white ring (Grusiniulus redikorzevi), yellow ball (Herculina oligosagittae), blue ball (Herculina polysagittae), pink star (Leptoiulus hastatus), red diamond (Metamastigophorophyllon martensi), yellow star (Omobrachyiulus macrourus (= O. m. abchasicus)), white star (Syrioiulus georgicus).

Figure 12. 

Map of eastern Georgia showing the distributions of some endemic or subendemic species. Designations: green ball (Alpinella waltheri), red ball (Brachydesmus assimilis), blue triangle (Cylindroiulus kacheticus), yellow ball (Cylindroiulus parvus), yellow ring (Hyleoglomeris specialis), orange square (Julus kubanus), red diamond (Leptoiulus tanymorphus), white ball (Pseudoflagellophorella eskovi), red ring (Pseudoflagellophorella papilioformis).

Conclusion

Ongoing research on the diplopod fauna of Georgia will undoubtedly reveal many more species and refine their distributions. This particularly concerns several genera of Julidae, including new cavernicolous and epigean ones (D. Antić, A. Evsyukov, B. Vagalinski, personal communications). As a result, the present paper must only be taken as provisional, marking the present state of the art and is certain to be updated in the near future.

Acknowledgements

This paper was executed in the framework of the project “Fauna of Georgia – Current Trends and Conservation”. The second author was supported by the Presidium of the Russian Academy of Sciences, Program No. 41 “Biodiversity of natural systems and biological resources of Russia”.

We are particularly grateful to A.S. Kandaurov (Tbilisi) who helped us generate the maps. Special thanks go to both reviewers, Hans Reip and Alexandr Evsyukov, for so critically and positively evaluating our work.

References

  • Antić DŽ, Makarov SE (2016) The Caucasus as a major hotspot of biodiversity: Evidence from the millipede family Anthroleucosomatidae (Diplopoda, Chordeumatida). Zootaxa 4211(1): 1–205. https://doi.org/10.11646/zootaxa.4211.1.1
  • Antić DŽ, Turbanov IS, Reboleira ASPS (2018) From the depths: Heterocaucaseuma deprofundum sp. nov., the world’s deepest-occurring millipede (Diplopoda, Chordeumatida, Anthroleucosomatidae) from caves in the western Caucasus. Zootaxa 4377(1): 110–124. https://doi.org/10.11646/zootaxa.4377.1.7
  • Bondyrev IV, Davitashvili ZV, Singh VP (2015) Natural Resources. The Geography of Georgia, Problems and Perspectives. World Regional Geography Book Series. Springer: Cham, 227 pp. https://doi.org/10.1007/978-3-319-05413-1_11
  • Chumachenko YA (2016) Millipede (Diplopoda) populations in a yew-boxtree grove in the Caucasian Nature Reserve, Russia. Zoologicheskii Zhurnal 95(4): 406–416. [In Russian, summary in English]
  • Enghoff H (1984) A revision of the Nopoiulinae, with notes on the classification of blaniulid millipedes (Diplopoda: Julida: Blaniulidae). Senckenbergiana biologica 64(4–6): 393–427.
  • Enghoff H (1990) A new species of Nopoiulus Menge 1851, subgenus Paranopoiulus Lohmander, 1939, from the Caucasus, with records of consubgeneric species, and the systematic position of Thassoblaniulus Mauriès 1985 (Diplopoda: Julida: Blaniulidae). Senckenbergiana biologica 70(4/6): 323–330.
  • Enghoff H (1985) The millipede family Nemasomatidae. With the description of a new genus, and a revision of Orinisobates (Diplopoda: Julida). Entomologica scandinavica 16: 27–67. https://doi.org/10.1163/187631285X00045
  • Enghoff H (1995) A revision of the Paectophyllini and Calyptophyllini: millipedes of the Middle East (Diplopoda: Julida: Julidae). Journal of Natural History 29: 685–786. https://doi.org/10.1080/00222939500770241
  • Enghoff H (2006) The millipedes of Turkey (Diplopoda). Steenstrupia 29(2): 175–198.
  • Evsyukov AP (2016) The millipede Pachyiulus krivolutskyi Golovatch, 1977, the easternmost species of the eastern Mediterranean genus Pachyiulus Berlese, 1883, endemic to the western Caucasus (Diplopoda: Julida: Julidae). Russian Entomological Journal 25(3): 299–306. https://doi.org/10.15298/rusentj.25.3.12
  • Evsyukov AP, Golovatch SI, Reip H (2016) The millipede genus Strongylosoma Brandt, 1833 in the Caucasus (Diplopoda, Polydesmida, Paradoxosomatidae). Acta Societatis Zoologicae Bohemicae 80: 7–16.
  • Evsyukov A, Golovatch S, Reip HS (2020) The millipede tribe Leptoiulini in the Caucasus, with notes on its generic composition (Diplopoda: Julida: Julidae). Zootaxa (in press).
  • Golovatch SI (1975) Two genera of Oniscomorpha (Diplopoda) new to the USSR fauna, found in Transcaucasia, and their zoogeographical relations. Zoologicheskii Zhurnal 54(10): 1566–1571. [In Russian, summary in English].
  • Golovatch SI (1976a) New or little-known species of Glomeridae (Diplopoda, Oniscomorpha). Zoologicheskii Zhurnal 55(6): 931–935. [In Russian, summary in English]
  • Golovatch SI (1976b) New species of polydesmidans (Polydesmida, Diplopoda) of the USSR. Zoologicheskii Zhurnal 55(10): 1567–1570. [In Russian, abstract in English]
  • Golovatch SI (1976c) Description of new species of Trachysphaera (Oniscomorpha; Diplopoda) from caves of Transcaucasia with remarks on T. rotundata (Lignau) 1911. Bulletin de la Société des Naturalistes de Moscou, Section Biologique [Byulleten Moskovskogo obshchestva ispytateley prirody, Otdel biologicheskiy] 81(5): 30–43. [In Russian, summary in English]
  • Golovatch SI (1977) New or little-known Julida (Diplopoda) of the Sataplia Nature Reserve (SSR Georgia). Bulletin de la Société des Naturalistes de Moscou, Section Biologique [Byulleten Moskovskogo obshchestva ispytateley prirody, Otdel biologicheskiy] 82(4): 46–51. [In Russian, summary in English]
  • Golovatch SI (1979) Three genera of Diplopoda-Chilognatha new to the USSR fauna. Zoologicheskii Zhurnal 58(3): 336–343. [In Russian, summary in English]
  • Golovatch SI (1981a) A review of the cavernicolous millipede fauna (Diplopoda) of the western Caucasus. Caves of Georgia [Peshchery Gruzii], Tbilisi 9: 108–111. [In Russian]
  • Golovatch SI (1981b) Some new forms of millipedes (Diplopoda) from the Caucasus. Annales Zoologici 36(5): 105–116.
  • Golovatch SI (1983) Une nouvelle espèce cavernicole du genre Leucogeorgia de la Transcaucasie (Diplopoda, Julidae). Fragmenta Entomologica 17(1): 47–50.
  • Golovatch SI (1984/85) Two new genera of cave-dwelling millipedes (Diplopoda), with remarks on the millipede fauna of West Caucasian caves. International Journal of Speleology 14(1/4): 39–50. https://doi.org/10.5038/1827-806X.14.1.5
  • Golovatch SI (1989a) Diplopoda of the Caucasus, 1. Glomeridellidae, with contributions to the fauna of Turkey. Senckenbergiana biologica 69(4/6): 405–419.
  • Golovatch SI (1989b) Diplopoda of the Caucasus, 2. Glomeridae, with contributions to the fauna of Turkey. Senckenbergiana biologica 69(4/6): 421–440.
  • Golovatch SI (1990) Diplopoda of the Caucasus, 3. Trachysphaeridae, with contributions to the fauna of Turkey. Senckenbergiana biologica 70(4/6): 331–358.
  • Golovatch SI (1993) Trachysphaera solida Golovatch, 1976, a revalidated Caucasian millipede species (Diplopoda Glomerida Trachysphaeridae). Arthropoda Selecta 2(4): 19–20.
  • Golovatch SI (2018) The millipede subfamily Pachyiulinae in Israel, with the description of a new species (Diplopoda, Julida, Julidae). Zoologicheskii Zhurnal 97(7): 791–805. https://doi.org/10.1134/S0044513418070073
  • Golovatch SI, Enghoff H (1990) [The millipede Nopoiulus kochii (Gervais, 1847) in the Caucasus (Diplopoda, Julida, Blaniulidae)]. In: Striganova BR (Ed.) Fauna of Terrestrial Invertebrates of the Caucasus. Nauka Publishers, Moscow, 114–118. [In Russian]
  • Golovatch SI, Kime RD (2009) Millipede (Diplopoda) distributions: A review. Soil Organisms 81(3): 565–597.
  • Golovatch SI, Turbanov IS (2017) The cave millipede Trachysphaera fragilis Golovatch, 1976, new to the fauna of Abkhazia, western Caucasus (Diplopoda: Glomerida: Glomeridae). Russian Entomological Journal 25(1): 101–102. https://doi.org/10.15298/rusentj.26.1.11
  • Golovatch SI (2018) A new cavernicolous species of the millipede genus Typhloglomeris Verhoeff, 1898 from western Georgia, Caucasus (Diplopoda: Glomerida: Glomeridellidae). Russian Entomological Journal 27(1): 101–104. https://doi.org/10.15298/rusentj.27.1.14
  • Golovatch SI, Evsyukov AP, Reip HS (2015) Colobognatha millipedes in the Caucasus (Diplopoda: Polyzoniida, Platydesmida, Siphonocryptida). Zootaxa 3972(2): 250–266. https://doi.org/10.11646/zootaxa.3972.2.6
  • Gulisashvili VZ (1964) Nature zones and natural and historical areas of the Caucasus. Nauka Publishers, Moscow, 328 pp. [In Russian]
  • Issaev VM (1911) Observations of millipedes Diplopoda at the Black Sea coast of the Caucasus]. Travaux de la Société Impériale des Naturalistes de Saint-Pétersbourg [Trudy Imperatorskogo Sankt-Peterburgskogo obshchestva estestvoispytateley] 42(1): 292–310. [In Russian, summary in German]
  • Kobakhidze DN (1965) A list of millipedes (Diplopoda) of SSR Georgia. Fragmenta Faunistica 11(21): 390–398. [In Russian, summaries in Polish and German]
  • Lazányi E, Vagalinski B (2013) Redefinition of the millipede subgenus Megaphyllum sensu stricto Verhoeff, 1894 and neotype designation for Megaphyllum austriacum (Latzel, 1884) (Myriapoda: Diplopoda: Julida: Julidae). Zootaxa 3741: 55–100. https://doi.org/10.11646/zootaxa.3741.1.2
  • Lignau N (1903) Myriapods of the Black Sea coast of the Caucasus. Die Myriopoden am Kaukasischen Schwarzmeerufer. Mémoires de la Société Impériale des Naturalistes de la Nouvelle-Russie [Zapiski Imperatorskogo Novorossiyskogo obshchestva estestvoispytateley. Odessa] 25(1): 82–149. [In Russian and German]
  • Lignau N (1915) Vielfüssler aus Abchasien. Annuaire du Musée Zoologique de l’Académie Impériale des Sciences de Petrograd [Ezhegodnik zoologicheskogo muzeya Imperatorskoy akademii nauk. Petrograd] 19: 349–401. [for 1914]
  • Lohmander H (1932) Neue transkaukasische Diplopoden. 4. Aufsatz über Diplopoden aus Sowjet-Union. Zoologischer Anzeiger 98(7/8): 171–182.
  • Lohmander H (1936) Über die Diplopoden des Kaukasusgebietes. Göteborgs Kungliga Vetenskaps- och Vitterhets-Samhälles Handlingar, Series 5B, 5(1): 1–196.
  • Read H (1992) The genus Cylindroiulus Verhoeff 1894 in the faunas of the Caucasus, Turkey and Iran (Myriapoda: Diplopoda: Julidae). Senckenbergiana biologica 72(4/6): 373–433.
  • Short M (2015) New records of Lophoproctus coecus Pocock, 1894 (Diplopoda, Polyxenida, Lophoproctidae) extend the range of the genus Lophoproctus. ZooKeys 510: 209–222. https://doi.org/10.3897/zookeys.510.8668
  • Short M, Vahtera V, Wesener T, Golovatch SI (2020) The millipede family Polyxenidae in the faunas of the Crimean Peninsula and Caucasus, with notes on some other Polyxenidae. Zootaxa (in press).
  • Vagalinski B, Lazányi E (2018) Revision of the millipede tribe Brachyiulini Verhoeff, 1909 (Diplopoda: Julida: Julidae), with descriptions of new taxa. Zootaxa 4421(1): 001–142. https://doi.org/10.11646/zootaxa.4421.1.1
  • Verhoeff KW (1930) Eine cavernicole Symphyognathen-Gattung aus Georgien, Transcaucasien. Mitteilungen über Höhlen- und Karstforschung 1930: 33–39.
  • Zuev RV (2017) The relict millipede Hirudicryptus abchasicus Golovatch, Evsyukov et Reip, 2015, new to the fauna of Russia (Diplopoda: Siphonocryptida: Siphonocryptidae). Russian Entomological Journal 26(3): 281–286. https://doi.org/10.15298/rusentj.26.3.12