taxonID	type	description	language	source
0E1287EEFF83FFC9FF6CFD82FD73FB4D.taxon	materials_examined	Holotype. VLS, Types- 32.1: sexually mature specimen as a whole mount, Lake Hazar, station 7, depth 20 m, 4.06.2012. Collected by N. Arslan. Type locality. Lake Hazar in eastern Anatolia (Turkey), 39.2 ° E, 38.2 ° N, 1248 m a. s. l. Paratypes. All three from Lake Hazar, collected by N. Arslan. VLS, Types- 32.2: cross sections on 3 slides, station not established, depth 50 m, 20.07.2007. ESOGU, (H) No 1: one sexually mature specimen in a whole mount, station 9, depth 100 m, 0 4.06.2012. SMNH Type 8528: one whole-mounted, sexually mature specimen (CE 14301 in Table 1), station 8, depth 65 m, 04.10.2011; with sequenced COI barcode, GenBank Acc. No. KF 366623. Other material. About 280 specimens, all from Lake Hazar, studied as whole mounts; seven of them with sequenced barcodes, deposited in SMNH, see Table 1. Further 77 whole-mounted specimens on 17 slides, and 8 serially sectioned specimens are deposited in VLS; the rest of material in ESOGU.	en	Timm, Tarmo, Arslan, Naime, Rüzgar, Melih, Martinsson, Svante, Erséus, Christer (2013): Oligochaeta (Annelida) of the profundal of Lake Hazar (Turkey), with description of Potamothrix alatus hazaricus n. ssp. Zootaxa 3716 (2): 144-156, DOI: 10.11646/zootaxa.3716.2.2
0E1287EEFF83FFC9FF6CFD82FD73FB4D.taxon	etymology	Etymology. Named after Lake Hazar, the type locality.	en	Timm, Tarmo, Arslan, Naime, Rüzgar, Melih, Martinsson, Svante, Erséus, Christer (2013): Oligochaeta (Annelida) of the profundal of Lake Hazar (Turkey), with description of Potamothrix alatus hazaricus n. ssp. Zootaxa 3716 (2): 144-156, DOI: 10.11646/zootaxa.3716.2.2
0E1287EEFF83FFC9FF6CFD82FD73FB4D.taxon	description	Description. Length of sexually mature individuals after fixation in 96 % ethanol 10 – 21 mm, most often 12 – 13 mm; after fixation in formalin or 70 % ethanol, ranging between 11 – 26 mm, in single cases 33 or 34 mm. Segment number from 45 to about 130, the maximum number not always in the longest individuals since the tail portion sometimes with short, just developing segments. Body wall smooth and transparent. Prostomium short, conical, separated from peristomium by a groove. Preclitellar portion of body widening gradually, in segment VIII 0.5 – 1.3 mm wide, the genital segments usually wider. Postclitellar portion gradually narrowing to 0.25 – 0.35 mm while intersegmental furrows become deeper. The genital segments X – XI almost always bear wide, lateral wing-like outgrowths produced by contraction of dorsoventral muscles. These " wings " begin anteriorly in the dorsolateral part of X as narrow strips (Figs 2.1, 2.8), proceed diagonally downwards, and continue in XI as thick lateral folds directed downwards and containing many internal organs; usually they do not reach XII. As a result, the ventral side of segment XI appears deeply concave in fixed specimens (Figs 2.1, 2.9, 2.10). Body dorso-ventrally flattened and thin in X – XI, the thinnest between X and XI where a distinct transversal groove crosses the ventral side (here body often only about 0.28 – 0.45 mm high). Spermathecal pores in X lateral, inconspicuous. Male pores in line of ventral chaetae, large, sometimes up to 100 Μm wide when penes are protruded. Both spermathecal and male pores open under the edges of the " wings ". Female pores not observed. Clitellum in XI – XII, thin. Hair chaetae (Fig. 2.2) present along the whole body, smooth, in preclitellar segments (0,1) 2 – 3 (4) per bundle, (100) 250 – 450 Μm long and about 2 Μm thick, longest in IV – VI, shortest in II. In postclitellar segments 0 – 2 hair chaetae, up to 160 – 190 Μm long. Pectinate chaetae (Fig. 2.3) in preclitellar segments with equally long teeth and several short intermediate denticles, (2,3) 4 – 6 per bundle, (80) 100 – 170 Μm long and 3.5 Μm thick, longest in IV – VII, shortest in II. In postclitellar dorsal bundles pectinates replaced by (1,2) 3 (4) small bifid chaetae, 80 – 120 Μm long. Preclitellar ventral chaetae (Fig. 2.4) bifid, with slightly longer and thinner upper tooth, (2,3) 4 – 6 (7,8) per bundle. Postclitellar ventral chaetae (Fig. 2.5) 3 – 4 (5) per bundle, 100 – 140 Μm long, with equal teeth, similar to the dorsal ones. Spermathecal chaetae (Fig. 2.6) in X, one on each side, sitting in thick (50 – 73 Μm) muscular-glandular pouches; sometimes absent, even in mature individuals. These chaetae straight or slightly sigmoid with bent Chloragogen tissue beginning in VI, the wide midgut in VIII. Dissepiments thin. Lateral vessels forming loops in ventral side of IV – VII; single dilated lateral vessels observed only in two sectioned individuals, in VII or VIII, but no regular " hearts ". Testes in X, ovaries in XI. Sperm sacs anteriorly often reaching IX (or even VIII) and posteriorly XI – XII, egg sac with eggs sometimes as far as XIV or XV. Spermatozoa in X and in sperm sacs organized in large, spindle-shaped bundles (Figs 2.8, 2.9). Male funnels at the anterior side of dissepiment 10 / 11, large and of variable shape, their posterior end sometimes piercing the dissepiment and reaching XI. Vasa deferentia (Figs 2.7, 2.9) straight, ascending from male funnels, and about 200 – 300 Μm long and 32 – 60 Μm wide, wall about 10 Μm thick, and lumen densely ciliated. Paired atria tripartite (Fig. 2.7). The first part in XI (Fig. 2.7: a 1) short but curved or winding, about 20 – 85 Μm wide, with lumen only 5 – 6 Μm wide, and consisting of dark-staining glandular cells similar to those of the prostate gland. Prostate gland attached to the first part of atrium and sometimes surrounded by a loop of the latter, slightly lobate, up to 125 – 250 Μm in diameter. Second part of atrium (Figs 2.7, 2.10: a 2) several times longer than body diameter, forming loops in the coelomic cavity of XI – XII; diameter variable (37 – 110 Μm), wall consisting of vacuolized epithelium, lumen irregularly wide. Third part of atrium (Figs 2.7, 2.9, 2.10: a 3) localized vertically in the lateral part (" wing ") of XI, 200 – 400 Μm long and 45 – 170 Μm wide, with dense wall consisting of narrow epithelial cells; its lumen 10 – 100 Μm wide, sometimes winding; the external muscle layer about 3 Μm thick. This terminal portion of atrium continuous with a 100 – 200 Μm long and proximally 65 – 145 Μm wide conical penis consisting of similar tissue; penis lumen sometimes dilated up to a width of 45 Μm. Penis usually retracted into spacious penial sac but often partially or completely protruded from the male pore. Penial sac 100 – 175 Μm wide in its proximal portion, with an inner circular fold near the base of the penis (Figs 2.7, 2.10). Paired spermathecae in X. Spermathecal ampulla roundish or bilobate (when extending above or below intestine into opposite side), usually about 300 – 400 Μm, maximally 600 – 700 Μm wide, with thin (5 Μm) and smooth wall when full of spermatozoa but with thicker (up to 20 Μm) and internally folded wall in slack portions (Fig. 2.8). Spermatozeugmata numerous, spindle-shaped, 55 – 105 Μm wide, longer than the diameter of ampulla. The filled ampullae can be pressed into XI. Spermathecal duct short (about 300 Μm), up to 100 Μm wide in proximal part and narrowing to 25 – 40 Μm distally, distinctly three-layered, with lumen of variable width. The funnel-shaped spermathecal pores lie in the posterior part of X, lateral to the spermathecal chaetae and below the body " wings ". Ecology. A taxon with mass occurrence in the strongly alkaline Lake Hazar, abundant in the profundal at all depths. Not known in any other water bodies.	en	Timm, Tarmo, Arslan, Naime, Rüzgar, Melih, Martinsson, Svante, Erséus, Christer (2013): Oligochaeta (Annelida) of the profundal of Lake Hazar (Turkey), with description of Potamothrix alatus hazaricus n. ssp. Zootaxa 3716 (2): 144-156, DOI: 10.11646/zootaxa.3716.2.2
0E1287EEFF81FFC5FF6CF9FEFD0EFB98.taxon	description	Genetic analyses of Potamothrix. For the COI gene, the maximum pairwise distance (p-distance as well as TN 93 distance) within Potamothix alatus paravanicus is 0.9 %, within P. a. hazaricus 0.8 %. Between these taxa, the p-distances are 5.3 – 6.2 %, the TN 93 distances 5.6 – 6.6 %. The distribution of all these distances is shown in Fig. 4, exposing a distinct barcoding gap. The p-distances between all Potamothrix species (with P. a. paravanicus and P. a. hazaricus together considered as one of them) vary between 13.9 and 20.5 %, and the TN 93 distances between 15.6 and 24.7 %. The p and TN 93 distances between the two subspecies of P. alatus and their suggested sister taxon P. bavaricus (see below and Fig. 5) are 16.1 – 17.3 % and 18.6 – 20.2 %, respectively. The ITS sequences are identical in all specimens of P. a. paravanicus and P. a. hazaricus; otherwise this marker shows considerable variation between the taxa included in the study.	en	Timm, Tarmo, Arslan, Naime, Rüzgar, Melih, Martinsson, Svante, Erséus, Christer (2013): Oligochaeta (Annelida) of the profundal of Lake Hazar (Turkey), with description of Potamothrix alatus hazaricus n. ssp. Zootaxa 3716 (2): 144-156, DOI: 10.11646/zootaxa.3716.2.2
0E1287EEFF81FFC5FF6CF9FEFD0EFB98.taxon	discussion	Discussion As mentioned in the introduction, only three species of Oligochaeta have previously been recorded from the littoral of Lake Hazar: Monopylephorus irroratus, Rhynchelmis sp. and Haplotaxis sp. The first of them is probably misidentified as it is known mostly in brackish water. None of them was met in our study, which however did not consider the littoral. Instead, three tubificid taxa, all new for Lake Hazar and one of them new for science, were found in profundal. Potamothrix alatus hazaricus n. ssp. appeared to be absolutely dominating at all stations deeper than 2 m while the two other occurred very seldom. P. a. hazaricus is rather similar to the nominotypical subspecies P. alatus alatus Finogenova, 1972 known from brackish waters of the Dnepr-Bug Estuary (Black Sea) and the Caspian Sea (Finogenova 1972, 1975). It differs from that form, apart from the freshwater habitat, in the longer upper tooth in the anterior ventral chaetae (the teeth of each chaeta being described as equally long in P. a. alatus), the more lateral position of the spermathecal pores (in line of ventral chaetae in P. a. alatus), and the thin, curved distal end of the spermathecal chaetae (tip of spermathecal chaetae not curved in P. a. alatus). Finogenova (1972) and Finogenova & Poddubnaja (1990) also mention the shorter (125 – 170 Μm) vas deferens in P. a. alatus, in comparison with the third subspecies, P. a. paravanicus Poddubnaja & Pataridze, 1989 (150 – 310 Μm; about the same, 200 – 300 Μm, was found in the new form).	en	Timm, Tarmo, Arslan, Naime, Rüzgar, Melih, Martinsson, Svante, Erséus, Christer (2013): Oligochaeta (Annelida) of the profundal of Lake Hazar (Turkey), with description of Potamothrix alatus hazaricus n. ssp. Zootaxa 3716 (2): 144-156, DOI: 10.11646/zootaxa.3716.2.2
0E1287EEFF81FFC5FF6CF9FEFD0EFB98.taxon	description	Potamothrix a. paravanicus was described from the profundal of the Transcaucasian lakes Paravani, Sagamo and Sevan, as a separate species, but which soon was attested to be a subspecies of P. alatus (Poddubnaja & Pataridze 1989; Finogenova & Poddubnaja 1990). It differs morphologically from the nominotypical subspecies and the Lake Hazar form in the complete lack of the lateral " wings " in the genital region of the body. For the individuals from Lakes Paravani and Sagamo in Georgia, Poddubnaja & Pataridze (1989) noted a large number of preclitellar ventral chaetae (6 – 10, seldom up to 12, per bundle) while we found much smaller numbers of them, only 2 – 6 per bundle, in Lake Sevan. Finogenova & Podubnaja (1990) noted the smaller number of dorsal chaetae in the Lake Sevan worms, in comparison with those from the Georgian lakes, but did not discuss it further. The upper tooth of the anterior ventral chaetae is longer in all lacustrine forms, i. e. those from Lakes Sevan, Hazar, and the Georgian lakes. Finogenova & Podubnaja (1990) described a single, thickened ventral chaeta (not observed by us) at the male pores in XI, in the Sevan material. Spermathecal chaetae have been described as distally straight in P. a. alatus, with slightly curved distal end in P. a. paravanicus both from Lake Paravani and Lake Sevan (our new material) but with thin and much curved tip in P. a. hazaricus n. ssp.; this difference, however, may depend on a different angle of observation. The lateral position of the spermathecal pores and the structure of the male ducts are similar in P. a. paravanicus from Lake Sevan and P. a. hazaricus. In the original description of P. a. paravanicus, the third, vertical portion the of atrium was depicted as shorter and interpreted as a muscular " penial bulb " (Poddubnaja & Pataridze 1989); the latter term, however, was not repeated by Finogenova & Poddubnaja (1990). Thus, P. a. paravanicus from Lake Sevan differs from P. a. hazaricus n. ssp. morphologically in the lack of " wings " (even in the case of similar fixation with strong alcohol) and in the slightly different shape of the spermathecal chaetae, while the structure of the reproductive system is virtually identical. The two freshwater subspecies, P. a. paravanicus (with populations in the lakes of Georgia and Armenia also being slightly different from each other) and P. a. hazaricus appear to be ecologically similar. They are abundant in the profundal of oligotrophic mountain lakes with alkaline water: 1100 – 3500 ind. m - 2 in Lake Sevan (Jenderedjian 1994) and 178 – 9067 ind. m - 2 in Lake Hazar, without the co-occurence of any other form of Potamothrix. Almost no other tubificids occur in this biotope in Lake Hazar, while the oligochaete fauna was found to be slightly more diverse in the profundal of Lake Sevan, and yet P. a. paravanicus comprised as much as 95.7 % of all individuals (Jenderedjan & Poddubnaja 1987). In greater depths of Lake Sevan, the individuals of P. a. paravanicus can grow very large, up to 55 mm long (Finogenova & Poddubnaja 1990), and reach an individual age of 20 years (Jenderedjian 1994). No enlarged individuals were observed in the deepest zone of Lake Hazar, while the lakes of Paravani and Sagamo are shallower. Species concepts and species delimitation have been issues of endless disputes in the biological literature. De Queiroz (2007) tried to alleviate the discussion by introducing his “ unified species concept ”, which defines species as “ separately evolving metapopulation lineages ”. He also pointed out that speciation is usually a gradual process, and that species delimitation therefore is a matter of finding as much evidence as possible (e. g., geographical separation, mitochondrial and nuclear gene differences, and morphological differences) that any two putative sister species indeed are evolving separately. In a more traditional approach, Mayr (1969, pp. 41 – 42) advocated the use of subspecies to taxonomically handle what may be regarded as incipient speciation, by recognizing subspecies as aggregates of “ phenotypically similar populations of a species, inhabiting a geographic subdivision of the range of the species, and differing taxonomically from other populations of the species ”; taxonomically here meaning “ sufficient diagnostic morphological characters ”. Mayr also noted that there may be both variation and overlap in these characters between subspecies. The subspecies category is still in common use for some vertebrate groups, but less so for most invertebrates, megadrile Oligochaeta (earthworms, Crassiclitellata) being a notable exception. The Potamothrix alatus case has a history of subspecies designations (Poddubnaja & Pataridze 1989; Finogenova & Poddubnaja 1990), and we faced the question whether to regard the new form from Lake Hazar as yet another subspecies, and, in particular, whether we were able to assess the latter’s taxonomic affinity to P. a. paravanicus. Our genetic data clearly shows that the worms from Lake Sevan (morphologically identified as paravanicus) and Lake Hazar (hazaricus) are closely related, and it is unfortunate that individuals of neither the nominotypical subspecies nor of P. a. paravanicus from its type locality were available to us. The COI barcoding gap (Fig. 4), associated with an approx. 6 % genetic distance suggests a considerable time of separation of the populations of P. a. paravanicus and P. a. hazaricus, although these genetic differences are much smaller than those observed between other species of Potamothrix, with COI distances of 16 – 25 % (TN 93). For the nuclear ITS region, however, the time of isolation apparently has not been long enough to develop variation. Our ITS data show no conclusive evidence that paravanicus and hazaricus do not belong to the same panmictic metapopulation. Nevertheless, the geographical distribution, and the slight differences in mitochondrial and morphological characters suggest that the two forms are in a phase of at least incipient speciation, and we find it justified to regard them as separate taxonomic entities. With De Queiroz’ (2007) reasoning, we find it likely that they represent two separately evolving lineages, i. e., we could propose them to be different species. However, as we have no genetic information on P. alatus alatus, and no direct or indirect evidence of reproductive isolation between any of the forms, we have chosen the conservative alternative of assigning the Lake Hazar form to a third (new) subspecies of P. alatus. Future research will hopefully resolve the taxonomic uncertainties about this complex. Without genetic information of P. alatus also from the brackish-water populations in the Ponto-Caspian Basin, it is difficult to judge whether the common ancestor of this complex was of euryhaline or freshwater origin. The isolation, dispersal and differentiation of the separate forms may have had a complex history, considering the geological past of the modern large Ponto-Caspian Seas. Many other Potamothrix spp. are diverse and abundant in this area, both in fresh and brackish water (Finogenova 1972, 1975), but their lack in these Transcaucasian and Turkish mountain lakes where P. alatus is present, remains an enigma. On the other hand, P. alatus has not been found in any of the many smaller Anatolian mountain and lowland lakes. Some of the latter are inhabited by a rich oligochaete fauna including several other species of Potamothrix (Yıldız & Balık 2005; Yıldız et al. 2005, 2007 a, 2012; Şahin & Yıldız 2011). Acknowledgements The Research Foundation of Eskişehir Osmangazi University financed this study under the project No. 201119008. The first author has been supported by the target financing of the Estonian Ministry of Education and Research (No. 0170006 s 08). The molecular work was supported by the Swedish Research Council and the Swedish Taxonomy initiative (ArtDatabanken, SLU). We cordially thank Drs Özgür Emiroğlu and Cansev Akkan-Kökçü who kindly provided a collection of samples in Lake Hazar; Dr. Susanna Hakobyan (Institute of Hydroecology and Ichthyology, Yerevan, Armenia) for the comparative material from Lake Sevan; Annette Bergter and Dennis Kallert, for collecting other material for DNA studies; and Anna Ansebo, Per Hjelmstedt, Emelie Lindquist, Maria Lindström and Marcus Svensson, for assistance in the molecular lab. We thank Drs Enrique Martιnez-Ansemil and Patrick Martin for their thorough and useful reviews.	en	Timm, Tarmo, Arslan, Naime, Rüzgar, Melih, Martinsson, Svante, Erséus, Christer (2013): Oligochaeta (Annelida) of the profundal of Lake Hazar (Turkey), with description of Potamothrix alatus hazaricus n. ssp. Zootaxa 3716 (2): 144-156, DOI: 10.11646/zootaxa.3716.2.2
