Type series of Electrogena ujhelyii (Sowa, 1981)

The original description of the species E. ujhelyii is based on a male imago (holotype), four other male imagines, eight female imagines and seven mature larvae (all paratypes). All of the type material originated from the environs of the village of Tihany (Hungary) on the Aszófö stream and was first kept at the Department of Hydrobiology (Jagiellonian University, Poland) (Sowa 1981). In 1997, R. Sowa’s collection was transferred to the Musée Cantonal de Zoologie Lausanne (Switzerland). Finally, this material was provided at our disposal on a long-term loan in April 2012, and is provisionally housed at Masaryk University, Brno, Czech Republic.

At present, the available type material on E. ujhelyii includes only five specimens preserved in alcohol.

(i) Holotype (Figs 1A–C, 2A, B), male imago, labelled as: “Ecdyonurus ujhelyii Sowa Holotype ♂ im. stream near Aszófö, Balaton Bassin, Hungary, 1.07.1976”; well preserved specimen in a separate tube, missing the left foreleg and the right hindleg; S Újhelyi leg.

(ii) Paratype I (Fig. 2C, D), male imago, labelled as: “E. ujhelyii Sowa Aszófö, stream in Balaton Bassin 1.vii.76”; “Aszófö 76.VII.1 leg. Ujh.” (Fig. 2E(1), E(2)); well preserved specimen, missing the right foreleg and the left hindleg; in a tube together with paratype II and paratype III (see below); S. Újhelyi leg.

(iii) Paratype II, male imago, label is the same as for paratype I; the specimen was preserved during the moult, with subimaginal skin; S Újhelyi leg.

(iv) Paratype III, female imago with preserved eggs, label is the same as for paratype I; incomplete specimen, missing legs.

(v) Paratype IV (Fig. 4A, B), mature male larva, labelled as: “Hungary: Aszófö 10.8.1958 leg. Újhelyi”.

Holotype label was prepared by Małgorzata Kłonowska-Olejnik (Kraków, Poland) in the 1990s; labels of paratypes were written by R Sowa and S Újhelyi. Hitherto, any slides of other specimens of the type series or their parts were not preserved.

Besides the original type material collected by S. Újhelyi, we collected and analysed topotypic material from the Aszófőii-séd brook near Aszófő (GPS loc.: 46°56.0648'N, 17°49.8379'E) sampled on July 12, 2012. Altogether, we used seven mature larvae for subsequent analyses and comparisons.

Type series of Electrogena samalorum (Landa, 1982)

The description of the species E. samalorum is based on imaginal and larval material, which was collected in the basins of the Elbe and Vistula Rivers. With the exception of the holotype (male imago reared from larva), female imago and two larvae, which have their localities, date of collection, and the name of collector clearly labelled, the collection data and other details for the other 13 larvae and three male imagines are indicated but not specified, which would be helpful for identification of the type material. Hence, when analysing the present volume of the type series of E. samalorum, we used the information from publications, original labels and the personal comments of T. Soldán. The type specimens, designated as E. samalorum, are preserved in alcohol and partly mounted on slides. Among the materials indicated as types of E. samalorum, we found two male imagines without genitalia in alcohol, labelled as “Brook–Valeč–Doupov North Bohemia–12.7.1956”. Marked locality and collection data correspond to that belonging to the paratype of female imago E. samalorum (see Landa and Soldán 1982: 34).

The identification of two males listed above has shown that one of them undoubtedly belongs to the type series E. samalorum based on the colouration of body, the colour pattern of lateral sides of abdominal terga II–VIII as described by Landa and Soldán (1982) and the structure of genitalia mounted on slide (see below). Another male imago probably belongs to the subgenus Helvetoraeticus of the genus Ecdyonurus according to the presence of the characteristic L-shape markings on the lateral sides of abdominal terga II–VIII, which is poorly visible due to the long-term preservation. It is possible that in this case we deal with the species Ecdyonurus subalpinus (Klapálek, 1907), mentioned by Landa (1969: 220) from Valeč village.

Together with the material in alcohol in the collection of the Institute of Entomology (Biology Centre of the Czech Academy of Sciences), the slide with genitalia of two E. samalorum males, was found and mounted as a single slide and labelled by M Kłonowska-Olejnik during her stay at the Institute of Entomology, Biology Centre of the Czech Academy of Science in 2002. One of two genitalia belongs to the paratype of the male imago, discussed above, and is labelled as: “Electrogena samalorum, Valeč brook, West Bohemia, 12.07.1956, ♂ im paratype, leg. V. Landa (preparat zewnętrzny) [external slide]” (Fig. 3A–C). The second male genitalia belong to the specimen of E. samalorum, and is labelled as: “E. samalorum Výrovka, Kostomlaty, 29.07.1961, ♂ im leg. V. Landa (preparat wewnętrzny) [internal slide]” (Fig. 3D, E). A complete specimen of this male has not been found and is probably lost; this specimen was not a part of type series.

Alcohol material:

(i) Paratype I (Fig. 3A, B), male imago, labelled as: “Brook–Valeč–Doupov North Bohemia–12.7.1956”; damaged specimen without forelegs, middle right leg, and hind left leg; genitalia mounted on slide; V Landa leg.

(ii) Paratype II, mature male larva; in same tube subimaginal skin also (probably belongs to the holotype male imago reared from larva); both labelled as: “Podhorod – paratypes”; significantly damaged larva; complete subimaginal skin; T Soldán leg.

(iii) Paratype III and paratype IV, male and female larvae, labelled as: “pot. u Lendak 25.7.61”; significantly damaged specimens; V Landa leg.

(iv) Paratype V and paratype VI, mature male larva and male larva, labelled as: “Heptagenia sp 1”, “Poprad / Podolince 24.6.1963”; significantly damaged larvae; V Landa leg.

(v) Paratype VII, mature female larva, labelled as: “Javorinka – Podspády / 26.8.63”; damaged larva; V Landa leg.

(vi) Paratype VIII, mature male larva, labelled as: “Potok u Maková / 18.6.63”; well preserved larva; V Landa leg.

(vii) Paratype IX, mature male larva, labelled as: “Pot. Lopušna / 18.6.63”; damaged larva; V Landa leg.

(viii) Paratype X, female larva, labelled as: “Pot. nad Brusnicou 27.7.61”; well preserved larva; V Landa leg.

(ix) Paratype XI and paratype XII, mature male and female larvae, labelled as: “Potok u Kastánie / 18.6.63”; damaged larvae; V Landa leg.

Slides (mounted based on paratypes XII and XIII):

(x) Paratype XII [mounted using paratype XII] (Figs 4C, F, 5A, B, D, F) and paratype XIII (Fig. 4E, G), female larvae, labelled as: “Electrogena samalorum Podhorod, Podhorský brook, 16.07.1975, L ♀ paratype A [another slide labelled as “L ♀ paratype B”], leg. T Soldán”; slides mounted with Liquide de Faure and labelled by M Kłonowska-Olejnik.

(xi) Paratype XIII (Figs 4D, 5C, E), female larva, labelled as: “Electrogena samalorum, Lopušna brook, 18.06.1963, L ♀ leg. V Landa”; idem.

(xii) male genitalia [paratype I (Fig. 3A, B); for details see above]; male genitalia [imago, not of type (Fig. 3D, E); for details see above]; idem.

In addition to the E. samalorum holotype and 19 paratypes indicated in the original description, hitherto, 13 paratypes have been preserved, of which three larval paratypes originated from the type locality. The holotype of the species has not been found, and is probably lost.

The line drawings of the morphological structures of the specimens belonging to the type series of Central European species were made using a Zeiss Axoiplan and Olympus BX41 microscopes, both equipped with a drawing attachment (camera lucida). The material was observed with a Leica M205 C binocular stereomicroscope; the eggs structure was investigated using phase-contrast microscope Di-Li 2026-P with 16 MP digital camera. Photographs of types were taken using a Leica Z16 APO microscope and processed with the Leica Application Suite™ Version 3.1.8 to obtain combined photographs with a suitable depth of field at the Staatliches Museum für Naturkunde Stuttgart. Photographs were subsequently enhanced with Adobe Photoshop™ CS3.

The numerical morphological characters defined by Carlo Belfiore for Electrogena species identification (Belfiore 1996, 1997) have been measured and minimum, maximum and mean value of each character was used for both species comparison. The preservation of available material did not allow to measure all defined characters; the characters based on number of fine setae or fragile body parts were thus omitted. The following characters were measured:

N_CBS number of comb-shaped bristles on fore margin of galea-lacinia;

N_CLW number of teeth on pretarsal claws;

N_BVF number of bristles on ventral side of femora near hind margin;

R_LBR total width of labrum divided by mean width of lateral lobes of labrum;

R_GLA relative distance between glossae (outer distance divided by inner distance between glossae);

R_GLB relative width of glossae (outer distance divided by width of glossae);

R_1GI relative width of 1^st gill plate;

R_4GI relative width of 4^th gill plate;

R_7GI relative width of 7^th gill plate.

For detailed description of the characters see Belfiore (1996, 1997) and Polášek et al. (2018).

Figs 1–3

Body colouration. The natural colour pattern is poorly preserved, especially in the paratype of the male imago of E. samalorum. Most changes were caused by long-term storage in alcohols of different concentrations and qualities. In the holotype and paratypes of E. ujhelyii, the general colour of the body is pale, dirty yellow, yellowish-brown to brown. The body colour of the preserved paratype of E. samalorum is distinctly darker than in all of the E. ujhelyii adult type specimens, with a brown to dark brown head and thorax and brown abdominal segments. Such a difference in coloration may be the result of inter-population variability. Besides, the lack of new topotype material on adult specimens of both species at our disposal makes it impossible to define the limit between inter- and intraspecific variability in colour pattern.

Head. In E. ujhelyii the head is light brown without conspicuous maculation; compound eyes widely separated, the sclerite joining the compound eyes weakly rounded, forming a wide U (Fig. 1B) (the same for E. samalorum based on the study of type material); compound eyes bluish-grey to whitish-grey apically, and blackish towards the base, without distinct rings laterally (Fig. 1A, C) (in E. samalorum: bicoloured laterally, with light dirty brown upper 2/3, and blackish grey lower 1/3 of eyes height [eyes whitish gray, dorsal surface darker without rings: original description of E. samalorum]).

Thorax. In E. ujhelyii the thorax is slightly darker than other body parts, with distinct contrast maculation dorsally and laterally (Fig. 1A–C) [“with slight violet pigmentation”: original description of E. ujhelyii]: pronotum with a pair of triangular light brown spots laterally; mesonotum with brown median longitudinal, mesonotal and lateroparapsidal sutures; anterior part of the anteronotal protuberance of the mesonotum, area between the antelateroparapsidal suture and the sublateroscutum, and scutoscutellar impression (area between posterior scutal protuberances) with brown markings; metanotum uniformly light dirty brown (all terminology based on Kluge 2004). Lateral and ventral sides of thorax light dirty brown, with brown anterior paracoxal suture. In E. samalorum the orientation of markings is the same as in E. ujhelyii holotype and paratypes, but the general coloration of thoracic structures is distinctly darker, with marked brown sutures and respective maculation [“thorax dark brown”: Landa and Soldán (1982)].

Legs. The forelegs of E. ujhelyii distinctly darker than the middle and hind legs (Fig. 1A); forefemur and foretibia intensely brown, markedly dark brown apically (the same in original description of E. samalorum); middle and hind legs uniformly whitish-yellow, transversal band on middle and hind femora not preserved (diffuse unclear macula in paratype of E. samalorum; the same in original description of E. ujhelyii).

Wings of E. ujhelyii translucent, pterostigmatic area dirty milky or yellowish coloured; longitudinal and transversal veins yellowish (the same in male paratype of E. samalorum). The characters of the veins’ colouration are different in both the original descriptions and preserved types, probably due to long-term storage in alcohol.

Abdominal segments. E. ujhelyii: light yellow to dirty yellowish-brown, segments (I) II–VI translucent or not transparent; traces of preserved dirty violet maculation relatively visible on abdominal terga II–VIII (poorly visible in holotype, more distinct in both paratypes); the pattern of abdominal terga similar to those described and figured by Sowa (1981: 376–377, fig. 1) and Bauernfeind and Soldán (2012: 299), but differs from the colour pattern figured by Haybach (2005: 42–43, fig. 5), with a dirty violet spot basolaterally near the anterior and posterior margins of the segments (the spot near the posterior margin of segments poorly visible). The sterna are uniformly yellowish brown; the ganglionic chain is not visible.

In the male paratype of E. samalorum the pattern of the abdominal terga poorly visible, but nevertheless corresponds with the original description (Landa and Soldán 1982: 32): a pair of elongated brown strokes (occasionally fused together on terga II, IV, and VI) near anterolateral margin of segments.

Genitalia. E. ujhelyii (Fig. 2A–D): The base of the forceps with small asymmetrical apically rounded projections laterally, broadly convex in the middle; the forceps yellowish-brown to brown, and paler distally (Fig. 2A, C); the penis lobes stout and divergent apically with relatively wide interspace, U or V shaped; the lobes widely rounded apically or slightly truncate along the outer margin [the similar shape of lobes is depicted by Sowa 1981: 376, fig. 2; Bauernfeind and Soldán 2012: 594, fig. 188], the lobes moderately expanded laterally; both ventral folds of the lobes well developed (Fig. 2B, D); a few small pointed setae occur basodorsally (the same as in the original description of E. ujhelyii). The titillators relatively broad, slightly asymmetrical, bluntly pointed at the tip, straight basally and strongly bent apically (ventral edge sinuous).

The structure of forceps base and penis lobes of the male paratype of E. samalorum completely corresponds with the original description (Fig. 3A, B, D, E; see also figs 2–4 in Landa and Soldán 1982: 33). The male genitalia of the specimen collected 29.vii.1961 generally with similar structure of penis lobes. However the lobes are closely touching, without deep interspace (Fig. 2D, E; the same shape of penis lobes is depicted for E. ujhelyii by Landolt et al. 1991: 467, fig. 8).

Only a single specimen of the female paratype of E. ujhelyii has been preserved hitherto. The preserved colour of the body is similar to those in male specimens. Compound eyes uniformly black, with thin brownish edging. The shape of subgenital and subanal plates corresponds to those described and figured by Sowa (1981: 377, fig. 3) and Haybach (2005: 42–43, fig. 2a, b). A single female paratype of E. samalorum has most probably been lost.

The structure of eggs is described and figured in details for E. ujhelyii by Sowa (1981: 377), Haybach (2005: 42–43, fig. 8) and Bauernfeind and Soldán (2012: 300, 631, fig. 188), and for E. samalorum by Landa and Soldán (1982: 32, 37, pl. 1, figs 1–4). We have studied egg chorion structure in the species E. ujhelyii, based on the material prepared from a single preserved female paratype. The result of our observations completely corresponds with the information published previously for both species.

Figs 4, 5

Body colouration. Like in adult specimens of the type series of E. ujhelyii and E. samalorum, the cuticular colouration of the studied paratypes of the larvae was also poorly preserved. Nevertheless, some aspects of colour pattern, which are important for identification and comparison of the taxa, are visible enough. The general colouration of the body in larvae of E. ujhelyii and E. samalorum is yellowish-brown to brown; a variable colour pattern is more or less preserved on the thorax, legs and abdomen.

Head of E. ujhelyii (paratype and topotypes) with broadly rounded anterior margin, the broadest part near to anterior end of eyes (Figs 4A, B); in E. samalorum the head capsule of similar shape, or the posterior margin occasionally truncated (Fig. 4C). The head colour of E. ujhelyii uniformly light brown to brown, without visible spots (the same in Landa and Soldán 1982; Bauernfeind and Soldán 2012), occasionally two small yellowish spots between the eyes and the lateral ocelli. In larval paratypes of E. samalorum the same head colour is observed; occasionally additional yellow spot between the base of the antennae and two smaller spots on both sides of the central ocellus. The labrum in E. ujhelyii and E. samalorum are shaped differently, slightly bent backwards or rather straight (Fig. 4D, E; Sowa 1981, fig. 4; Landa and Soldán 1982, fig. 8); a row of a relatively stout bluntly pointed setae available on the ventral side of the labrum (Fig. 4G).

Thoracic colour pattern is variable in both species, but generally corresponds to those in the original descriptions. Generally, the pronotum with two elongated transversal whitish spots near the anterior margin; the lateral sides of the pronotum regularly rounded, slightly stretched laterally with two yellowish strokes along the outer margin (Fig. 4B). The mesonotum with several elongated whitish-yellow markings of variable shape, and two diffuse spots near the wing pad bases in E. ujhelyii and E. samalorum.

Legs. The coxae of both species with distinct brown marking around the segment; the femora yellowish-brown with a pair of transversal zigzag-like light brown spots proximally and distally; the tip of the femora light brown; tibiae contrasted, with ¾ of the distal part light brown and ¼ of the proximal part yellow; tarsi light brown and slightly darker at the tip; pretarsal claw brown with 2–4 teeth (occasionally with one strong tooth, Fig. 5A). The characters of leg setation (including dorsal femoral setation) correspond with those in contributions published by Sowa (1981), Landa and Soldán (1982), Haybach and Belfiore (2003) and Bauernfeind and Soldán (2012).

Abdominal segments of both species with two pairs of diffuse yellow to light brown spots on a brown background on terga (I) II–VII (a pair of smaller spots close to the anterior margin of the segment centrally; a second pair of spots near the posterior margin of the segment laterally); tergite VIII occasionally with a large diffuse light spot centrally; tergite IX with a diffuse U-shaped light spot centrally; tergum X with elongated yellow spots centrally and smaller spots laterally (generally the same colour pattern was described for E. samalorum by Landa and Soldán 1982). Some differences occur between the observed shapes of the 1^st and 7^th gill plates in paratypes and topotypes of E. ujhelyii and E. samalorum, and drawings in the original descriptions are noted (see Fig. 5C, D, E). Nevertheless, in all materials studied, the 7^th gill abruptly tapers in its distal third. Additionally, Landa and Soldán (1982: fig. 12) depicted a row of broad nearly triangular or rectangular jagged teeth apically along the posterior margin of the abdominal terga. All observed specimens can be characterised by the presence of a mainly regular row of stout triangular teeth, alternating with a group of 1–3 smaller teeth (Fig. 5F).

The comparison of minimum, mean and maximum of selected numerical characters is presented in Tab. 1. We did not find any reliable character for delimitation of both studied species using the defined set of numerical characters. The range of all characters strongly overlapped, usually with values of those for E. samalorum within the range of E. ujhelyii. The only character with apparent difference between both species was R_LBR (total width of labrum divided by mean width of lateral lobes of labrum). Nevertheless the preservation of type material (namely of E. samalorum) and thus the number of measurements of this character did not allow the statistical evaluation.