First Records of Potamic Leech Fauna of Eastern Siberia , Russia

We studied the fauna of leech and leech-like species inhabiting main water streams of Eastern Siberia and its tributaries, which are attributed to Lake Baikal basin and Lena River basin. Here we present their list for the �rst time. is study was mainly aimed for free-living parasitic and carnivorous leeches whereas piscine parasites were not included specially. In total, the potamic leech fauna of Eastern Siberia includes 12 described species belonging to 10 genera. Representatives of three unidenti�ed species of two genera Erpobdella and Barbronia have been also recorded.


Introduction
e fauna of Siberian leeches has never been object of a target study.Fragmentary data are presented in the papers of Lukin and Epstein [1,2].Recent paper of Kaygorodova [3] corrected the species list of fauna of the unique Siberian Lake Baikal.To date, 20 leech species are reported from there.
Representatives of other leech families of Eastern Siberia have not been mentioned in the literature.
is study is aimed to �ll the gap in our knowledge of species diversity of Siberian leeches.

Methodology
We used in this study the extensive biological material collected by the authors in the Chechuy River (September 2010, August 2011), the Kirenga River, the Lena River, and the Belaya River (August 2011), the Kudareyka River (August 2011-May 2012), and the Angara River (October 2011-May 2012).
Piscine leeches were collected by hand directly from infected �sh and amphipods.Free-living leeches were washed from macrophytes and different substrates.Biological material was �xed in ethanol with gradually increasing the concentration from 10% to 80%.
Morphological analysis was conducted by Irina A. Kaygorodova with a stereomicroscope WILD M4C-61 149 and a binocular microscope Axiostar plus (Carl Zeiss Microimaging Gmb).Species de�nition was done with identi�cation keys [1,2,8] and the original descriptions [9] according to the modern classi�cation of the group.Natalya V. Sorokovikiva revealed differences in species of the genus Erpobdella.
Examined material of leech species collected by the authors is deposited in Limnological Institute, Siberian Branch of the Russian Academy of Sciences (LIN SB RAS, Irkutsk, Russia).

Dataset Description
e dataset associated with this Dataset Paper consists of one item which is described as follows.).List of leech and leech-like species inhabiting main river basins of Eastern Siberia: Lena River basin and Lake Baikal basin.Chechuj River, Chaya River, Chuja River, Kirenga River, and Lena River belong to Lena River basin.Upper Angara River, Kudarejka River, Belaja River, Selenga River, and Angara River belong to Lake Baikal basin.e dataset consists of a checklist composed of 15 taxa.e exact systematic position is stated for all leech species.Each involved species has a brief taxonomic characteristic (see Table 1).

Dataset Item 1 (Table
(1) Acanthobdella peledina Grube, 1851.Archaic freshwater leech-like clitellates are semipermanent parasites, restricted exclusively to salmonoid �sh. A. peledina has a wide area of habitat at high latitudes of the Northern Palearctic-from Norway on the west to the Kolyma Region on the east [2] and in North America [10,11].erefore, despite a wide area, the species refers to rare species and listed as endangered in Eastern Siberia.Within Eastern Siberia, A. peledina is recorded from the Chechuj River, the Chaya River, the Chuja River, tributaries of the Lena River, and the Upper Angara River belonging to Lake Baikal basin.Eastern Siberian specimens have bright green coloration, and the ratio of body length to width is signi�cantly less than the rest A. peledina from other water systems of Eurasia [7].
(2) eromyzon maculosum (Rathke, 1862).Rare Palaearctic species is known as parasite of waterfowl.T. maculosum is a boreal relict species for freshwaters of Northeast Europe (Russia, Sweden), Asia (Commander Islands, Loktak Lake in India), and both American continents [12].Four adult animals were sampled from rotten sweep wood in the Kudarejka River.ese specimens have typical body shape and body sizes (up to 40 mm), but not usual marking.Siberian individuals are transparent with a pale olive tint in contrast to the dark-colored European representatives.
(3) eromyzon tessulatum (Müller, 1774).Palaearctic species was found only in two rivers of Lake Baikal basin-Angara and its right tributary Kudarejka.Individuals were located at underside of the stones at a depth of 0.5-1 m. e species is known as bloodsucker of birds.Specimens are 10-12 mm in length and about 2 mm in width and can stretch up to 15-17 mm, becoming 1 mm in width.ere are �ve annuli between male and female genital pores.
(4) Hemiclepsis marginata (Müller, 1774).It is widespread Palaearctic species and bloodsucker of �shes, tadpoles, and amphipods.e species was found in both main river basins (the Kirenga River and the Angara River) on stones and macrophytes at a depth of 0.2-1.0 m.Living animals were greenish with length of 14-16 mm and width of 3 mm.Alcohol-�xed specimens rapidly lost a beautiful intravital colouring.
(5) Helobdella stagnalis (Linnaeus, 1758).is species is cosmopolite.It is considered one of the most common freshwater leeches in the world.Within Lake Baikal proper, H. stagnalis inhabits shallow bays and salinas [3].Our collection has samples from the Chechuj River, the Kirenga River, the Lena River, the Kudarejka River, the Belaja River, and the Angara River.
(6) Glossiphonia complanata (Linnaeus, 1758).Holarctic species is widespread in Eastern Siberia.Specimens of our collection were caught in shallow zone of the Chechuj River, the Kirenga River, the Lena River, the Kudarejka River, and the Angara River.Life cycle of G. complanata is typical for the majority of the genus.It prefers to sit on the rocks or slowly crawling.is leech feeds almost exclusively on molluscs and sometimes oligochaetous worms or larvae of insects.e size is about 10-16 mm.On the dorsal side, there are three pairs of longitudinal rows of papillae.G. complanata like other glossiphoniids takes care of nurture.
(7) Glossiphonia verrucata (Müller, 1844).Up to now G. verrucata was known from northern Europe (Scandinavia, British Isles, and Germany) as boreo-alpine species.is species is for the �rst time recorded for Siberia.Representatives of the species were found in slowly running parts of the Lena River and some of its tributaries.In addition to the distinctive morphological features, this species is notable for larger body size, reaching in Siberian populations 30 mm in length.
(8) Alboglossiphonia hyalina (Müller, 1774).It is Palaearctic species.Its distribution over a vast area is irregularly.A. hyalina is a suctorial freshwater sit-and-wait predator, feeding on gastropods.It inhabits shallow and slowly running places of the Lena River on the North and peaceful backwater of the Belaja River on the South of the Eastern Siberia.It is very small translucent yellowish or amber-coloured leeches with maximal body length of 10 mm.ere is no any dark pigmentation.As typical glossiphoniid, it shows touching parental care.
(10) Baicalobdella torquata (Grube, 1871).It is endemic to Lake Baikal.It is a typical component of the littoral zone of open Baikal [3].B. torquata is the only Baikal endemic leech, which penetrated beyond this unique lake-in the upper part of the Angara River, from its source up to 220 km downstream.e small leeches are 5-8 mm in length and 2-3 mm in width.Body colour varies from light green to pale rusty retaining a characteristic mosaic pattern on the dorsal side of urosome.B. torquata sucks the blood of endemic amphipods Eulimnogammarus verrucosus (Gerstfeldt, 1858) (Crustacea, Amphipoda).
(11) Cystobranchus mammillatus (Malm, 1863).It is a rare Palaearctic species and a speci�c parasite of burbot (Lota lota).ese leeches are located in the branchial cavity and branchiae.Its body length is up to 35 mm.Distribution of C. mammillatus is con�ned to northern waters including large tributaries of Lake Baikal such as the Selenga River (found in 1.5 km from the con�uence of Lake Baikal) and the Upper Angara River as well as the Yenisey River.
(12) Haemopis sanguisuga (Linnaeus, 1758).It inhabits only Palaearctic waters, where it is widespread and can be attributed even to trans-Palearctic group.It is a predator of small vertebrates and invertebrates.H. sanguisuga belongs to very voracious predators, which ingest their prey completely or tear to big pieces.ese leeches were collected from the Kirenga River and the Lena River (Lena River basin) and the Kudarejka River and the Angara River (Lake Baikal basin).(13) Erpobdella sp. 1. is species was found so far in the Angara River and its tributary Belaja River.With a powerful pharynx, the Erpobdella ingests completely or partially different aquatic animals, small annelids, crustaceans, insect larvae, molluscs, and spawn and even young �shes and does not refuse dead animals and smaller specimens of own species.e big-sized leeches are about 35 mm in length and 3-4 mm in width.e leeches have little pigmentation.
(14) Erpobdella sp. 2. ese leeches are common in the Eastern Siberian rivers.We found them in Lena and Kirenga (Lena River basin) and in Kudarejka, Selenga, and Angara (Lake Baikal basin).Worms have relatively large sizes; the length of their body is up to 70 mm.ere is a dark pigmentation on the dorsal side.e species has the same lifestyle as the Erpobdella sp. 1.
(15) Barbronia sp.One specimen of the species was found in slough of the Angara River within urban area of Irkutsk city.Ethanol-�xed leech is 34 mm in length, without visible colouring and pigmentation.ere is accessory copulatory organ that is typical for representatives of genus Barbronia.
e table consists of the names of the rivers and species' names inhibiting these rivers.

Concluding Remarks
Nowadays, a list of 15 species rank taxa in Eastern Siberia is documented.is species diversity includes both widespread Holarctic and Palaearctic species as well as rare and endemic species from 6 families and 12 genera.Five species of the checklist were identi�ed for the �rst time in Eastern Siberia, namely, A. hyalina, G. verrucata, Erpobdella sp. 1, Erpobdella sp. 2, and Barbronia sp.
Two species of the genus eromyzon are indicated here as conventional in current systematics, T. maculosum and T. tessulatum, although both species have morphological features that do not �t well within the type species description.Local variety of T. tessulatum probably corresponds better to T. tesselatoides (Livanow, 1902) by a smaller body size and, more importantly, by a position of genital pores [13].However, Lukin [14] expressed his doubt about the independence of the species status of T. tesselatoides and reduced it to T. tessulatum.Until it has not yet been revised, we should use this species name.
As to our Siberian representatives of T. maculosum, their morphology also deviates from the species description.Since an intravital colouring and pigmentation are taxonomically important species-speci�c features in Hirudinea, the species status of these leeches has to be checked by the revision of this group.
e widespread Palaearctic species Piscicola geometra (Linnaeus, 1761) was deliberately excluded from this list.First of all, we did not study piscine leeches ad hoc.Second, we have never met this species on Eastern Siberian �sh.ird, analysis of the literature revealed that the hypothesis of a possible wide distribution of P. geometra in Siberia is not supported by direct evidence.

Dataset Availability
e dataset associated with this Dataset Paper is dedicated to the public domain using the CC0 waiver and is available at http://dx.doi.org/10.7167/2013/362683/dataset.

T 1 :
A list of leech-like and true leech species inhabiting Eastern Siberian water streams, containing 15 species with their taxonomic hierarchy data.