Occurrence dataset: High-altitude records of leeches in the world (elevation ≥ 2,500 m)

This dataset is a supplement to our review paper entitled "Taxonomic diversity of leeches on the world's highest mountain ranges and plateaus" (Bolotov et al. 2025 in Zool. J. Linn. Soc.; https://doi.org/10.1093/zoolinnean/zlaf051). Additionally, we deposited here the figures and supplementary material from this paper.The dataset contains information on available records of leeches from high-altitude areas of the world (<i>n</i> = 140; elevation ≥ 2,500 m) that were compiled based on the body of literature and museum collection sources. The high-altitude records of leeches were georeferenced with Google Earth (https://earth.google.com/web) using information on the collecting localities. Where possible, the altitudes of precise localities were verified using Google Earth, because specimen labels and published works often contain inaccurate elevation estimates.To georeference the historical sampling localities of P. K. Kozlov (Plotnikov 1907), we examined his travel diaries and maps of expedition routes (Kozlov 1905; Kozlov 1906). Additionally, we consulted the list of localities with one (latitude) or both coordinates that were estimated based on astronomical observations by P. K. Kozlov (Tachalov 1907).Altogether 127 occurrences were successfully georeferenced. In contrast, high-altitude records of leeches from North America (Colorado, Rocky Mountains) listed by Herrmann (1970) do not contain precise data on collecting localities. Hence, we were unable to georeference these records but used data on the maximum altitude occurrence for each species (<i>N</i> = 13).<b>FIGURE LEGENDS</b><b>Figure 1.</b> Map of high-altitude occurrences of leeches (≥ 2,500 m). Regions: Alps (<i>1</i>), Tibetan Plateau (<i>2</i>), Himalaya (<i>3</i>), East African Mts. (<i>4</i>), Rocky Mts. (<i>5</i>), and Andes (<i>6</i>). The georeferenced occurrence data is presented in Supporting Information, Dataset S1. The blue circles indicate records of freshwater species; and the light green circles indicate records of land-dwelling species. The dashed blue area shows Colorado (Rocky Mts.), the occurrences of freshwater leeches from which were not georeferenced (see Material and Methods for detail).<b>Figure 2.</b> Examples of alpine habitats in high-altitude areas (&gt; 2,500 m), inhabited by leeches. A, Tibetan Plateau, China; B, Himalaya, Northern India; C, Mount Kenya, East African Mts., Kenya; D, Cordillera de Mérida, Andes, Venezuela. Photos: Valentina Artamonova (A), Maxim Vinarski (B), Gennady Dvoryankin (C), and Georgy Kalmykov (D).<b>Figure 3.</b> Environmental preferences and ranges of leeches (Hirudinida) from major high-altitude regions (≥ 2,500 m) based on our dataset (Supporting Information, Dataset S1). A, number of freshwater and land-dwelling species. B, number of high-altitude endemic and widespread species.<b>Figure 4.</b> Ranking of the maximum altitude of occurrences of leeches (Hirudinida) by families (A) and by major high-altitude regions (B). The red line indicates the threshold value of the altitude (≥ 2,500 m) that was selected for this research. The raw altitude data is presented in Supporting Information, Dataset S1.<b>Figure 5.</b> Historical specimens of leeches from the Tibetan Plateau (Qinghai, China) collected by P.K. Kozlov's expedition in 1900-1901. Abbreviations: D, dorsal view; V, ventral view; co, common genital opening; mg, male gonopore; and fg, female gonopore. A-C, <i>Alboglossiphonia </i>cf. <i>szechuanensis </i>(Chen, 1959) (museum lot ZIN 1-‘Gl-heteroclita’): A, specimen No. 2; B, specimen No. 3; and C, collection label: “[Swamp spring], Dza-Chu [=Zha Chu River] Valley, 12,100' a.s.l. [approx. 3,700 m], Blue [=Yangtze] River basin, [Julian calendar date: late July – mid-August 1900; actual date: August 1900], Tibetan Expedition, [Kaznakov leg.]” (habitat, dates, and collector information are based on published works: Kozlov 1905; Kozlov 1906; Plotnikov 1907). D-F, <i>Theromyzon maculosum</i> (Rathke, 1862) (museum lot No. ZIN 14/44093): D, adult specimen No. 1; E, sub-adult specimen No. 2; and F, collection label: “Lake Alyk-Nor, southern slope of Burkhan-Burda [Mountain Range], 12,700' a.l. [4,100 m alt. based on Google Earth], 29.v.1900 [Julian calendar date; actual date: 11 June 1900], Tibetan Expedition leg.”. G-I, <i>Theromyzon mollissimum</i> (Grube, 1871) (museum lot No. ZIN 13/44092): G, adult specimen No. 1; H, adult specimen No. 2; and I, collection label: “Eastern Qaidam, Khara-Usu [=Hala Wusu] River, approx. 8,600' a.l. [2,800 m alt. based on Google Earth], [2] August 1901 [Julian calendar date; actual date: 15 August 1901], Tibetan Expedition leg.”. Scale bars: 1 mm (A, B) and 2 mm (D, E, G, and H). Photographs of all specimens from the three lots are presented on figshare (https://doi.org/10.6084/m9.figshare.28025390).<b>Figure 6.</b> Size frequency histograms of waterfowl-associated leech samples from the Tibetan Plateau based on the body length measurements (ethanol-preserved specimens). A, <i>Theromyzon maculosum</i> (Rathke, 1862), Lake Alyk-Nor, altitude of 4,100 m, 11 June 1900 (N = 64; see Supporting Information, Table S1 for raw data). B, <i>Theromyzon mollissimum</i> (Grube, 1871), Khara-Usu [=Hala Wusu] River, altitude of approx. 2,800 m, 15 August 1901 (N = 273; see Supporting Information, Table S2 for raw data).<b>SUPPORTING INFORMATION:</b><b>Dataset S1. </b>High-altitude records of leeches in the world (elevation ≥ 2,500 m)<b>Table S1.</b> Measurements and life cycle stages of high-altitude historical sample of <i>Theromyzon maculosum</i> (Rathke, 1862) (Hirudinida: Glossiphoniidae) from Tibet (museum lot ZIN 14/44093; N = 64).<b>Table S2.</b> Measurements and life cycle stages of high-altitude historical sample of <i>Theromyzon mollissimum</i> (Grube, 1871) (Hirudinida: Glossiphoniidae) from Tibet (museum lot ZIN 13/44092; N = 273).<b>Table S3.</b> Measurements of high-altitude historical samples of <i>Alboglossiphonia </i>cf. <i>szechuanensis </i>(Chen, 1959) (Hirudinida: Glossiphoniidae) from Tibet (museum lot ZIN 1-'Gl-heteroclita'; N = 5).<b>Figure S1.</b> Ranking of the maximum altitude of occurrences of freshwater and land-dwelling leeches based on our dataset (Supporting Information, Dataset S1). The red line indicates the lower altitudinal limit (2,500 m) that was selected for this research.<br><b>References</b>Bolotov IN, Eliseeva TA, Gofarov MY, Tsiplenkina IG, Kondakov AV. Taxonomic diversity of leeches on the world's highest mountain ranges and plateaus. Zoological Journal of the Linnean Society 2005. https://doi.org/10.1093/zoolinnean/zlaf051Herrmann SJ. Systematics, distribution, and ecology of Colorado Hirudinea. American Midland Naturalist 1970;83:1–37. https://doi.org/10.2307/2424004Kozlov PK. Through Mongolia to the boundaries of Tibet. In: Mongolia and Kam: Proceedings of the Expedition of the Imperial Russian Geographic Society carried out in 1899-1901 under the leadership of P. K. Kozlov. Vol. 1, Part 1. Saint Petersburg: Herold, 1905; 1–256. [in Russian]Kozlov PK. Kam and way back. In: Grigoriev AV (ed) Mongolia and Kam: Proceedings of the Expedition of the Imperial Russian Geographic Society carried out in 1899-1901 under the leadership of P. K. Kozlov. Vol. 1, Part 2. Saint Petersburg: Herold, 1906; 1–732. [in Russian]Plotnikov V. Glossosiphoniidae, Hirudinidae et Herpobdellidae du Musée Zoologique de l'Académie Impériale des Sciences. Annuaire du Musée zoologique de l'Académie des sciences de St. Pétersbourg 1907;10:133–158. https://www.biodiversitylibrary.org/item/121130#page/5 [in Russian]Tachalov N. On astronomical observations produced by P. K. Kozlov during the expedition to Mongolia and Kham in 1899-1901. In: Grigoriev AV (ed) Mongolia and Kham: Proceedings of the Expedition of the Imperial Russian Geographical Society carried out in 1899-1901 under the leadership of P. K. Kozlov. Vol. 3. Part 1. Saint Petersburg: Herold, 1907; 1–7. https://doi.org/10.20676/00000043 [in Russian]