Eukoenenia lanai Christian, 2014

Christian, Erhard, Isaia, Marco, Paschetta, Mauro & Bruckner, Alexander, 2014, Differentiation among cave populations of the Eukoenenia spelaea species-complex (Arachnida: Palpigradi) in the southwestern Alps, Zootaxa 3794 (1), pp. 52-86 : 79-82

Eukoenenia lanai Christian , species nova

( Figures 1 , 2 , 5 M , 6 , 10 M , 12 M , 13 M , 14 M , 20 , 21 , 23–25 )

Material examined. Holotype male: Italy, Piemonte, Province of Cueno, Demonte, Miniera superiore di Monfieis (44°21′44″N, 07°16′00″E, 1750 m a.s.l.); 12 September 2010, leg. E. Lana. Two paratypes: 1 female, 1 male; same locality, date, and collector.

Deposition. Museum of Natural History , Vienna, Austria, Arachnological Collection. Acquisition numbers 21.878 (holotype), 21.879 (paratype female), 21.880 (paratype male) .

Etymology. The specific epithet is a patronym in honour of Enrico Lana, eminent speleobiologist, photographer and collector of rare subterranean animals.

Diagnosis. A species with all characters of the E. spelaea complex as described above. Body length 2100 µm or more; each finger of chelicera with 8 teeth; lateral organ with 3 blades; 5 deuto-tritosternal setae; forked seta absent on I bta4; proximal forked seta on I ta3 only half length of rod seta; some or all of sternites IV–VI with more than 3+3 setae a; segment XI of opisthosoma with (9–)10 setae; fusules on first genital lobe of male inserted on dome-shaped bases.

Description. Morphometric data are given in Table 1 under ♀ 05, ♂ 06 and ♂ 07 (holotype).

General appearance. Large Eukoenenia , with a body length of 2100–2170 µm. Shape and pubescence of trunk as in other members of the E. spelaea complex. Trunk of live individuals yellowish, particularly the opisthosoma.

Prosoma. Frontal organ 40 µm long (holotype), with two lanceolate, pointed branches. Lateral organ with 3 reticulated, 45–49 µm-long blades that are parallel-sided with a pointed tip ( Fig. 5 M ). Propeltidium with 10+10 setae, the shortest (29–31 µm) in central position, the longest (53–57 µm) laterally in posterior half. Setae t 1, t 2 and t 3 of metapeltidium 74–85, 132–145 and 82–98 µm long, respectively. Labrum with usual cuticular pattern and 5+5 short setae. Deuto-tritosternum with 5 setae of 47–54 µm, arranged in a wide V. Chaetotaxy of chelicera and dentition of fingers as in E. roscia . Coxal chaetotaxy as described above for spelaea group. Curved seta near tip of pedipalp weakly and asymmetrically forked, the typical fs is inserted somewhat behind. Leg I with 7 trichobothria in usual arrangement and a total of 7 forked setae. The ta3 of leg I has 4 fs in distal half, 1–1–2: fs 1 is only half length of the nearby rs; in all specimens fs 2 is inserted much closer to m than to cs ( Fig. 10 M ). I bta3 not as slender as in E. strinatii and E. roscia , length/width 3.06–3.19 ( Fig. 12 M ); seta r inserted at 48–53% of article length. I bta4 without fs. IV bta slender, all ratios very similar to those of E. roscia ; r <grt <esd; tip of r does not project beyond distal end of article ( Fig. 13 M ).

Opisthosoma. Anterior tergites with t 1, t 3, s on segment II and t 1, t 2, t 3, s on III–VI. Sternites IV–VI each with a pair of submedian circular structures and lateral setae s 1 and s 2; more than 3+3 submedian setae a on at least one of the sternites IV–VI, the maximum observed (N = 3) was 4 per side ( Figs 6 & 14 M ). E. lanai has by far the relatively longest setae a among all populations investigated (see above). The setation of the terminal segments ( Table 3 ) is partly variable; segment VII carries 13–17 setae, segment XI has 9 (female) or 10 setae (the two males). The 2 pairs of setae on the intermediate ring of the flagellum are of equal length. In the holotype, the flagellum (detached, under separate coverslip) is preserved from the third article to the tip ( Fig. 21 ). Length (in µm) and number of setae (in brackets; “+” indicates the presence of an apical crown) are for article 3: 217 (10+), 4: 214 (9), 5: 176 (8+), 6: 212 (8), 7: 171 (8+), 8: 227 (8), 9: 184 (8+), 10: 249 (7), 11: 207 (7), 12: 239 (7), 13: 179 (7), 14: 123 (6 and 1 terminal seta). On article 3, the longest seta measures 277 µm, the longest spine of the apical crown 68 µm. Photographs of two live individuals show 14 flagellar articles and the relatively longest flagellum observed in this study (1.9–2.0× trunk length, Table 4 ).

Female genital area. First lobe has 7+3 setae on each side; the innermost of the 3 apical setae measures 24 µm, it is somewhat shorter than the others. Each half of second lobe possesses 3 setae. The total formula is 7+3/3.

Male genital area. Chaetotaxy (2+9+2f/3/4) and general shape of genital lobes as in E. strinatii (cf. Fig. 19 ). The fusules, however, are inserted on dome-shaped bases ( Fig. 20 ), a character that separates E. lanai from the other species of the present study. In the holotype, the longest seta on the first lobe measures 98 µm, the fusules 60 µm.

Figures

FIGURE 1. Habitus of cave palpigrades of the Eukoenenia spelaea complex. From above: E. spelaea from Ardovská, Slovakia; E. strinatii from Bossea; and E. lanai sp. n. from Monfieis. Photographs courtesy of Ľubomír Kováč (top) and Enrico Lana.

FIGURE 2. Study area and cave populations of palpigrades. B = Bossea, C = Caudano, F = Fornaci, L = Litrôn, M = Monfieis, P = Partigiano. Not sampled for this study: CL = Grotte de la Clue and SV = Grotte de Saint-Vincent-de-Mélan. Type localities and new species are highlighted. Base map © 2012 Google, Cne/Spot Image, Tele Atlas.

FIGURE 5. Lateral organ. B: Bossea ♀ (E. strinatii), L: Litrôn ♂ (E. bonadonai), C: Caudano ♀ (E. bonadonai), M: Monfieis ♀ (E. lanai sp. n.), F: Fornaci ♀ (E. roscia sp. n.). Images enlarged to same size to facilitate comparison. The blades are 40–50 µm long.

FIGURE 6. Lateral organ and opisthosomal chaetotaxy of Eukoenenia specimens from the six Italian cave populations. The right column shows the values for published specimens and the two comparative females (Ardovská, Griffen). The top line of each box gives the number of blades in the lateral organs (one digit, if symmetric), the three lines below give the numbers of setae a on sternites IV–VI (left ǀ right).

FIGURE 10. Tip of leg I. Modified setae: rs = rod seta; fs = forked seta; m = macroseta; cs = curved seta; the remaining setae are out of focus. B: Bossea ♀ (E. strinatii), C: Caudano ♀ (E. bonadonai), P: Partigiano ♀ (E. spelaea), M: Monfieis ♀ (E. lanai sp. n.), A: Ardovská ♀ (E. spelaea), G: Griffen ♀ (E. spelaea). Scale bar: 20 µm.

FIGURE 12. Third and fourth basitarsus of leg I. For better comparison of the shape, the third basitarsi are all enlarged to the same length. B: Bossea ♂ (E. strinatii), C: Caudano ♂ (E. bonadonai), L: Litrôn ♂ (E. bonadonai), M: Monfieis ♂ (E. lanai sp. n.), P: Partigiano ♀ (E. spelaea), F: Fornaci ♀ (E. roscia sp. n.), A: Ardovská ♀ (E. spelaea), G: Griffen ♀ (E. spelaea).

FIGURE 13. Basitarsus of leg IV. The basitarsi are all enlarged to the same length. Specimens as in Fig. 12.

FIGURE 14. Setae a on sternite VI. B: Bossea ♂ (E. strinatii), C: Caudano ♂ (E. bonadonai), L: Litrôn ♂ (E. bonadonai), M: Monfieis ♂ (E. lanai sp. n.), P: Partigiano ♀ (E. spelaea), F: Fornaci ♂ (E. roscia sp. n.), A: Ardovská ♀ (E. spelaea with one seta a absent as an individual aberration), G: Griffen ♀ (E. spelaea). Midline = scale bar: 50 µm.

FIGURE 19. Male genitalia in ventral view. One side of the first lobe (left), tips of the second lobe (above), and of the third lobe (below) of a E. strinatii ♂ from Bossea. Fusules are marked f1, f2. Scale bar: 50 µm.

FIGURE 20. Fusules (f1, f2) on first genital lobe of a male from Monfieis (E. lanai sp. n.). The fusules are inserted on domeshaped bases. Scale bar: 20 µm.

FIGURE 21. Flagellum. Left: articles IV–VI of a Monfieis ♂ (E. lanai sp. n.; scale bar: 100 µm). Right: the same articles of a E. mirabilis ♀ (soil-dwelling) from Bergeggi, Liguria, for comparison (scale bar: 20 µm). Note apical crown of cuticular spines on articles III (at the very top of the images) and V.

FIGURE 23. Principal component analysis based on measurements of 29 Eukoenenia individuals (females and males) from six Italian and two comparative populations (A, G). G = Griffen, A = Ardovská, P = Partigiano, C = Caudano, L = Litrôn, F = Fornaci, B = Bossea, M = Monfieis.

FIGURE 24. Graphic representation of the measurements used for the morphometric analysis (data from Tables 1 & 2, in µm). Only females included. Initials of caves as in Fig. 23 (non-Italian comparative populations in brackets).

FIGURE 25. Graphic representation of the values of commonly used morphological indices (data from Tables 1 & 2). Only females included. Initials of caves as in Fig. 23.