Corresponding author: Irina A. Kaygorodova (
Academic editor: Fredric Govedich
Fedorova LI, Kaygorodova IA (2022) First data on the Hirudinea fauna of lotic ecosystems of the Khanty-Mansi Autonomous Area (Russia). ZooKeys 1082: 73–85.
Khanty-Mansi Autonomous Area is located in the central part of the West Siberian Plain, stretching for almost 1400 km from the Ural ridge in the west to the Ob-Yenisei watershed in the east, and extending about 800 km from north to south (
Many rivers of the Khanty-Mansi Autonomous Area are undergoing anthropogenic transformations mainly associated with large-scale oil production. Greater damage to ecosystems is caused not only by oil pollution
Leeches are an integral component of any aquatic biocenoses. Their role is especially significant in freshwater benthic communities of coastal zones where they are the most abundant (
To date, no object-orientated studies on the leech fauna of the Khanty-Mansi Area have been performed. The only study reports on three species of
This paper presents the first purposeful study of the leech fauna from the watercourses in the Khanty-Mansi Autonomous Area, debunking the myth the aquatic invertebrate fauna in the north of Western Siberia is impoverished.
Leech sampling was carried out from 6 June to 20 September 2020 at 44 locations along 25 large and small watercourses belonging to the Bolshoi Yugan, Severnaya Sosva, Konda-Irtysh, and Ob watershed basins (Fig.
Schematic map of geographic location of the Khanty-Mansi Autonomous Area and studied lotic systems. River basins: I = Severnaya Sosva, II = Konda-Irtysh, III = Ob, and IV = Bolshoi Yugan.
The use of conventional hydrobiological equipment (sweep net, dredge, scraper, bottom grab, etc.) is less effective in catching leeches than for many other aquatic invertebrates; therefore, the collection of leeches was done manually. To do this, we examined aquatic plants and potential host animals to detect parasitic and predatory leeches, as well as various underwater objects (rotten tree, driftwood, stones, etc.) to which leeches can attach. Collected individuals were fixed after preliminary anesthesia in a low-concentration alcohol solution and kept in 80% ethanol. Morphological analysis was conducted using a stereomicroscope MSP-2 var. 2 (LOMO). Species affiliation was determined using existing systematic keys (
An object-oriented hydrobiological survey carried out in the warm season of 2020 resulted in finding leeches in 20 of 25 examined watercourses of the Khanty-Mansi Autonomous Area. This indicates a high frequency of their occurrence in nature. Leeches inhabit at least 88% of the region’s rivers. However, not all surveyed water bodies turned out to be suitable for leeches. In particular, we could not find them in some watercourses, namely, in the Shaitanka rivers, Bezymyannyi Creek (Severnaya Sosva river basin), in two nameless brooks (Ob river basin), and the Pach-peu River (Bolshoi Yugan river basin). Very cold water, fast current, and, hence, biotic poverty of streams, creeks, and brooks make these habitats less suitable for leeches. There were no leeches in the navigable sections of the Irtysh. In the Pach-peu River, leeches were absent probably due to poor water quality.
In this first faunistic leech species list, 10 species were documented. The species diversity includes leeches from two orders (
Our study did not confirm the information provided in the literature about findings of
The checklist includes both widespread Palaearctic species (
The species composition of the Khanty-Mansi hirudofauna has an uneven distribution (Table
Species composition of the
Taxa | River basins | |||
---|---|---|---|---|
Ob | Konda-Irtysh | Severnaya Sosva | Bolshoi Yugan | |
|
– | + | – | – |
|
++ | +++ | + | ++ |
|
++ | ++ | – | + |
|
+ | ++ | – | + |
|
++ | + | + | + |
|
+ | – | – | – |
+ | – | – | – | |
|
++ | ++ | ++ | + |
|
++ | + | + | + |
|
+ | – | – | + |
Within the Severnaya Sosva river network, the
Leeches from the Konda-Irtysh and Bolshoi Yugan watershed basins were represented by seven species:
Species
Listed below is the information about the species composition of
Palaearctic region. This species is rare in Europe (
Not an abundant species. Point occurrence in floodplain water bodies of the Irtysh River (61°0'58"N, 69°9'26"E).
Palaearctic region. Previously mentioned as Holarctic. However, recent molecular studies confuted its findings in North America (
Ob River (
Palaearctic region. Distributed in northern, central, and eastern Europe (
Schekurya River (
Palaearctic region. Although
Not an abundant species. Point occurrence in Shaitanskaya River (
Transpalaearctic species. This is one of the most common leech species inhabiting freshwater ecosystems in Eurasia.
Yatria River (
Palaearctic region. Species has wide but uneven distribution. In Europe, this species is common in countries with temperate climates. Rarely found in North Africa. It has a nonuniform distribution in the Caucasus, Central Asia, Western and Eastern Siberia, the Far East, China, and Japan (
Ob River (
A single specimen from the Chumpas River (
Piscine leech has middle size, its body length is 22 mm and diameter is 3.5 mm. Sucker size is commensurate with the width of the body. Dorsal pigmentation is absent, unlike the widespread
Widespread in the Palaearctic region.
Yatria River (
Palaearctic region. This species occurs in Europe from the Netherlands (
Schekurya River (
Palaearctic region.
Ob River (
We are grateful to E.A. Zvyagina (Lomonosov Moscow State University) and N.V. Filippova (Ugra State University) for help in organizing the expedition.
This study was carried out within the framework of research program of the Department of Education and Youth Policy of the Khanty-Mansiysk Autonomous Okrug, Russia (no. 121052800096–4) and basic research programs of the Ministry of Education and Science, Russia, no. 0279–2021–0011 (121032300198–2).