Holarctic family Lumbricidae continues to be refined, now providing approx. 670 valid taxa (plus ca. 55 uncertain species) from a total of 1, 130 names in ca. 63 genera – or about 10% of all known megadrile earthworms – and contributing just 33 (or ~22%) of the 150 or so globally ubiquitous cosmopolitan species (Blakemore 2008a, 2010, 2012b). Natural distribution is from Vancouver Island in Canada, throughout Europe and Central Asia to Korea and Japan. Stephenson (1925) noted that no native species were known from Tibet or Mongolia, whereas Gates (1967 p. 172) concluded: “In Manchuria, Kobayashi (1940) found that an annual rainfall of less than 400 mm (ca 16 inches) was unfavourable to earthworms. He likewise was mainly interested in native taxa. ‘In the region where the amount of annual rainfall is less than 400 mm, no endemic species can exist.’ (p. 308). Some at least, if not all, of the supposed endemics, when revised, will fall into synonymies of more or less widely spread anthropochores. Probably no single megadrile will prove to be autochthonous (evolved in, and not found elsewhere) in either Manchuria and Mongolia”.

Prior to the current work, the only previous Mongolian record the author is aware of was for the giant Eisenia magnifica (Svetlov 1957: 183), formerly in genus Allolobophora, from the north-western Altai mountains bordering several countries thus its distribution is not restricted to Mongolia. A national report on sustainable development cites vermicompost production since 2005 by Ulziin Gol LLC a local company in Selenge Province, presumably using mundane compost-worm, Eisenia fetida (Savigny, 1826) that for the last 30 yrs, and currently, includes as its ultimate of 15 subsequent synonyms Eisenia andrei andrei Bouché, 1972 as determined by Easton (1983), Blakemore (2003, 2004 p. 97, 2006, 2008a, b, 2010, 2012a, b, 2013a, b), Csuzdi and Zicsi (2005 p. 143), Blakemore et al. (2010), Blakemore and Grygier (2011), and Csuzdi (2012).

Specimens, fixed in 75–80 % ethanol, lodged in National Institute of Biological Resources are available for transfer to a suitable Mongol national institute if regulations require. Description is in the author’s usual style (e.g. Blakemore 2010). Cytochrome c oxidase subunit 1 (COI barcode) sequences (Hebert et al. 2003) obtained using methods similar to those provided in Blakemore et al. (2010) are appended with analyses via megaBLAST (www.blast.ncbi.nlm.nih.gov/BLAST.cgi) and MEGA 5.1 (wwww.megasoftware.net) (Tamura et al. 2011). A checklist of boreal Palaearctic / Siberian Eisenia nordenskioldi species-complex, revised from those of Perel’ (1979, 1997), Easton (1983) and Blakemore (2004, 2008a, b), is presented in Appendix 2. Abbreviations are rhs- right hand-side, lhs – left hs; TP – tubercula pubertates; DP – dorsal pore; mid-D = mid-dorsal line.

Interest in natural and acquired species ranges intensifies with global climate concerns. Specific responses to extreme physico-chemical factors are also of interest. Lee (1985 p. 44) reports Ghilarov’s claim that Eisenia nordenskioldi revives after long periods of being frozen, with freeze tolerance down to -30°C recorded for Eisenia nordenskioldi (subspecies?) by Holmstrup and Petersen (1997) and Berman and Leirikh (1985). Berman et al. (2002) further report on adaptation to arid conditions. Its sibling species, Eisenia fetida, common at altitude in the Himalayas (Stephenson 1925), may be found in Spitzbergen or Siberia wandering on or under snow (some reports possibly misidentifications of Eisenia nordenskioldi?); and it is also found in deserts (e.g. of Arizona by Gates 1967) and Csuzdi and Pavlicek (2005a, b) recently report it from Mar Saba and Samaria, Israel and Jordan. Eisenia fetida was further located at hot springs on subarctic Iceland and a fumarole at subtropical Raoul Island, N.Z.; its experimental temperature range is given as -2° to +40°C (Lee 1985 tab. 2).

Regarding natural distributions of lumbricid earthworms and species identities, after synonymy of Helodrilus (Bimastus) indicus Michaelsen, 1907, Gates (1958 p. 6, 1972 p. 108) delineated the natural southern boundary of Lumbricidae in Asia north of the Hindu Kush and Karakorum ranges and from Baluchistan west to the Pacific. He thought endemicity of any lumbricid south of Tian Shan and Altai Mts (where giant Eisenia magnifica occurs) into Mongolia or Northeast China would be quite unexpected. Gates (1972 p. 108) said that his synonymy (in Aporrectodea rosea) was not accepted by all authors, indeed Easton (1983 p. 478) resurrected Michaelsen’s taxon as Dendrobaena indica, and whereas transfer was questioned by others (cf. genus Healyella), Dr Cs. Csuzdi (2003 pers. comm.) informed that “I have seen the two type specimens. It seems a distinct species with unknown origin”. Regardless of its generic status, Dendrobaena indica or Helodrilus indicus can no longer be thought to have been endemic to India, and neither is athecal Kashmiri Allolobophora prashadi (Stephenson, 1922) as noted below.

Although Perel’ (1969 p. 62) thought it likely that Allolobophora harbinensis Kobayashi, 1940 belonged in synonymy of Eisenia nordenskioldi, the characters Kobayashi (1940) provided showed similarity to his other three new species that were comparable to Helodrilus (Allolobophora) prashadi Stephenson, 1922: 440, another non-native from India and, after Gates (1958), usually placed in synonymy of Aporrectodea rosea. Kobayashi’s data are given in Table 2, albeit all five taxa are currently held in the extensive (four page!) synonym list of Aporrectodea rosea (Savigny, 1826) (e.g., by Gates 1974, Easton 1983, Blakemore 2008a, 2010, 2012; cf.Tab. 2). Quoting the generic definition by Michaelsen (1900 p. 471), Kobayashi (1940) presumably attributed his taxa to Eisenia as then defined only when the spermathecae were present and in or near the median-dorsal line, otherwise he put them into Allolobophora (including parthenogens?).

Possibly Allolobophora harbinensis is a sexual morph (and therefore an invalid synonym) of Allolobophora hataii. Alternatively, it may represent the amphimixic form of a separate taxon or, equally possible, they are subspecies of either of Eisenia fetida (most likely) or onon nordenskioldi but with spermathecal pores more lateral in cd lines. Nothing of substance separates Kobayashi’s Allolobophora jeholensis from his page prior Allolobophora dairenensis so it, at least, should be subsumed. Both have the flared clitella in 29-31 characteristic of Aporrectodea rosea and neither aresuperficially distinguishable from Aporrectodea rosea itself defined with clitellum in 25, 26-31, 32 and TP 29-½31, 31 or thereabouts, plus several combinations of setal tumescences. Internally Aporrectodea rosea has spermathecae absent or in 9/10/11 dorsally; calciferous glands in 10; U-shaped nephridial bladders and it has a compound typhlosole – see Blakemore (2010, 2012). Thus possibly some or all of Kobayashi’s taxa, as well as athecal Allolobophora prashadi, may either be Northeast China candidates for Aporrectodea rosea or for parts of the Eisenia fetida and Eisenia nordenskioldi spp.-complexes. Interestingly, Kobayashi (1940 pp. 282-287) describes Eisenia nordenskioldi sub-species as well as both Eisenia rosea and Eisenia fetida from Northeast China! But, since he omits crucial morphological information (“?s” in Tab. 2), more work is therefore required for resolution of all Kobayashi’s taxa – extending to DNA analysis of primary types, if locatable and their DNA viable. More probably (topotypic) neotypes will be required – as per Blakemore et al. (2010) – to permit objective comparison with complete and correct identifications on GenBank notwithstanding. Such tasks far exceed the brief of the present study.

For Eisenia nordenskioldi spp-complex, Perel’ (1969) separated her Eisenia nordenskioldi polypapillata from the nominal type and a similarly unpigmented, Eisenia nordenskioldi pallida (Malevic, 1956) on the basis of its numerous papillae between the male pores and clitellum, and on the wider distance separating the spermathecal pores from the mid-dorsal line (Tab. 1). Dr Perel (pers. comm. Dec. 2012) now suspects both subspecies are variations of the same taxon, however this too would require reference to the earlier pallida and acystis types (if locatable).

As with Eisenia fetida, mere colour differentiation is probably inadequate. Kobayashi (1940), whose taxa were subsequently combined irrespective of their pigmentation, said typical Eisenia nordenskioldi somewhat resembled Eisenia fetida but were not quite so banded intersegmentally. In contrast, Zicsi (1972) noted his Eisenia nordenskioldi specimens reddish in life, when preserved were colourless. Thus wide intraspecific colour variations seem permissible in parts of Eisenia nordenskioldi too.

Some possibly similar species from the Siberian region are Dendrodriloides grandis perelae (Kvavadze, 1973) [syn. Eisenia perelae polysegmentica Kvavadze, 1979 (non Kvavadze, 1973)], Eisenia sibirica Perel & Graphodatsky, 1985, Eisenia tracta Perel, 1985, Eisenia ventripapillata Perel, 1985 and Eisenia angusta Perel, 1994. In the opinion of its author, Eisenia ventripapillata is certainly a separate species to Eisenia nordenskioldi; however, it is perhaps closer to Eisenia acystis (T. Perel pers. comm. via Anna Leirikh, 27^th Feb. 2013). The diagnostic comparison of Eisenia ventripapillata given was as an unpigmented worm with clitellum extending to 32/33 and TP occupying three segments at least from ½28 or 28, whereas in Eisenia nordenskioldi the TP is always from segment 29 (and clitellum to 33/34).

Another Siberian species claimed to be similar but separate from Eisenia nordenskioldi is Eisenia atlavinyteae Perel & Graphodatsky 1984: 611 (sometime spelt “atlavynteae”, “atlaviniteae” or “atlavyntae” and authored “Perel, Graf., 1985”). Vsevolodova-Perel and Bulatova (2008a, b) commented on polyploidy: “Amphimictic autopolyploid races of two species of the Asian genus Eisenia, E. nordenskioldi and E. atlaviniteae [sic, lapsus], are widespread in Siberia, from its southern boundary to the arctic region, while polyploid Lumbricidae in the East-European plain, except for the Volga region, are represented mainly by parthenogenetic forms of other genera.”

Polyploidy is often associated with parthenogenetic species complexes. Sexual forms of the Eisenia nordenskioldi species-complex are reported to have even ploidy levels (orthoploids with 2× being equal to 36 rather than 24 according to Bulatova et al., 1987) ranging from 2n-8n, while the only previously recorded parthenogen is a deep-burrowing and athecal septaploid (7n), Eisenia nordenskioldi acystis (Michaelsen, 1903) (with 10× = 110-l15) found in the Talasskii Alatau mountains (Perel and Grafodatsky 1983) that Viktorov (1997) called a “race” (and, if so, an invalid taxon). Other taxa like Eisenia nordenskioldi pallida may be di- or tetraploid, and ecological differences of polyploid vs. diploid morphs shows wide distribution and variation: the more wide, the higher the ploidy level (Perel’ 1987, Grafodatsky et al. 1982, Perel and Bulatova 2008a, b).

Regarding distribution of the species-complex, Kobayashi (1940, 1941) found Eisenia nordenskioldi nordenskioldi to be prevalent in the DongBei Region of China and North Korea; differentiating his more darkly pigmented Eisenia nordenskioldi manshurica subspecies (Appendix 2 cf.Tab. 1) that he also thought similar to Caucasian Eisenia nordenskioldi lagodechiensis (Michaelsen, 1910) but lacking its glandular male pores, as do all the other sub-species. Dr Perel’s Eisenia nordenskioldi polypapillata is from the Dzungarian Alatau mountain range at Almaty Province of south-eastern Kazakhstan. The current species are from much further east in Mongolian river tributaries flowing from the Khentii Mountains to the steppes.

Perel’ (1987) states: “..Eisenia nordenskioldi in southern Kazakhstan, Siberia and the Far East is represented by the poorly pigmented form pallida. The typical form is significantly more widespread, in Siberia reaching the regions of the far north and also occurring in the eastern and south-eastern parts of the European USSR” and Perel’ (1997 p. 22) gives the location of dubious Eisenia nordenskioldi pallida morph or subspecies in “..Китая и на севере Корея.” (= China and in northern Korea). These citations by Perel (1979 pp. 75, 267, 1997 pp. 69, 70) may be mistaken if priority yields to Eisenia acystis (Michaelsen, 1903), thus leaving Eisenia nordenskioldi pallida Malevics, 1956 as species inquirendum. Historical reports of the nominal taxon from the Azores and Hawaii are probable misidentifications with Eisenia fetida (as noted by Michaelsen, 1900 p. 476); while Garman (1888 p. 73) said that Eisenia nordenskioldi was: “Obtained by Eisen in Siberia; credited to North America by Vejdovsky”, i.e., its USA credit was mistaken too.

Confusion between these sibling species may have been common. Both Michaelsen (1903, 1910) and Gates (1972 p. 103) recognized variability of (parthenogenetic and/or polyploidal) morphs and close relationships of Siberian Eisenia nordenskioldi (Eisen, 1879) with European Eisenia fetida (Savigny, 1826), Gates saying they were “indistinguishable specifically from each other by any of the characters of the classical system” and differing substantially only in the number of atyphlosolate posterior segments. The whole Eisenia fetida species-complex yet requires evaluation with consideration of ICZN compliance. For example, as noted above, Jaenike (1982) avoided types and overlooked the synonyms with priority over Eisenia andrei, the first being Eisenia semifasciatus (Burmeister, 1835) which has not yet been tested and neither have any of Kobayashi’s species as noted herein. Moreover, at least Stop-Bowitz (1969, tab. V) maintains Scandinavian Eisenia fasciata Backlund, 1948 which is often included in Eisenia fetida synonymy by most authors along with ca. 14 other names, but more often than not (especially in chemical/molecular studies by non-taxonomists) these available synonyms are completely overlooked (see also the discussion in Blakemore et al. 2010).

This notion, that components of the Eisenia fetida and Eisenia nordenskioldi spp. complexes are indistinct, is gradually being falsified by refined genetic information complementing the morphology of taxa under rules of ICZN (1999) that disallows nomenclatural availability to varietal forms, morphs or races. However, further considerations are, firstly, that genetics only reveals a part of the information on a taxon while a morphological character is often controlled and manifest from interplay of several genes throughout the organism’s ontogeny and phylogeny (with ontogeny defined as the history of structural change in any biotic entity whether a cell, an organism, or a population of organisms, i.e., a species). Secondly, regardless of data being based on DNA or morphology, or on both of these, it is only the condition pertaining to the ICZN (1999) defined type-specimen that defines the scientifically-named species. Hence a chronic confusion of all Eisenia fetida/andrei results – see Blakemore (2006, 2010, 2012b, 2013a, b) and Blakemore et al. (2010), the latter while also providing a model from the first COI barcode of an earthworm’s neotype, comments on the shortcomings of all previous molecular studies. Just as Blakemore (2011) observed regarding a New Zealand paper: “as with several previous molecular phylogenetic works, the only errors in their otherwise informative study are the names”.

The genus is a contrivance itself defined by its type-species’ type; ditto a family.

Despite morphological limitations (Tabs 1–2), objective DNA data (Appendix 1) and regulated ICZN taxonomy (Appendix 2) complement comfortably herein (Fig. 4).