Traegaardhia subterranea Zacharda, 2010

Zacharda, Miloslav, Fong, Daniel, Hobbs Iii, Horton H., Piva, Erminio, Slay, Michael E. & Taylor, Steven J., 2010, 2474, Zootaxa 2474, pp. 1-64 : 52-58

Traegaardhia subterranea Zacharda , n. sp. ( Figs 37–40)

Material examined

HOLOTYPE: adult female, Italy, Lessinian Mts , Valdagno (Vicenza), Amarcord Cave (6391 V/ VI), 650 m a.s.l., coll. G. Peretto, E. Piva, 5.3.1994, deposited in the Museum of Biological Diversity, Ohio State University, Type No. OSAL0007429; paratype (deposited with the holotype): adult female, same data as holotype, OSAL0007430.

Diagnosis

Cheliceral digits long, slender, arched; fixed digit smooth along masticatory surface and with prebasal lateroventral fissure located distad of articulation of cheliceral digits and proximad of insertion of proximal cheliceral seta. Masticatory surface of cheliceral movable digit smooth or only finely serrate along approximately distal third. Proximal cheliceral seta inserted distad of articulation of movable digit; tip of proximal seta reaches insertion of distal seta. Palpal tarsus same length as femorogenu, with small apical tubercle and thirteen long pubescent setae. Prodorsal bothridial setae sc 1 reach to insertions of opisthosomal c 1 setae. Opisthosomal setae c 1, d 1 reach almost to insertions of successive setae. Rhagidial organ I comprised of four rhagidial solenidia (ω) lying in tandem in confluent depressions; stellate famulus (ε) inserted between first and second proximal rhagidial solenidia antiaxially; rhagidial organ II with three rhagidial solenidia lying in tandem in confluent depressions, small spiniform famulus (ε) subtending proximal rhagidial solenidion. Coxae I, II, III, IV with 3-1-6-3 setae, respectively. Neotrichy in genital region: seven to eight pairs of aggenital setae.

Affinities

The long, slender, arched, cheliceral digits in T. subterranea n. sp. partly resemble those in representatives of the genus Poecilophysis Zacharda, 1980 . However, in Poecilophysis the distal cheliceral seta is always inserted dorsally, not dorsolaterally as it is in Traegaardhia .

Traegaardhia subterranea n. sp. is very similar to Foveacheles thaleri n. sp. (see below) from which it can be distinguished by the following principal characteristics: (1) The masticatory surface of the cheliceral movable digit is smooth or only finely serrate along approximately distal third of masticatory surface; in F. thaleri the movable digit along approximately distal third of masticatory surface is distinctly denticulate. (2) The tip of the proximal cheliceral seta reaches insertion of the distal seta; in F. thaleri the distance between insertions of the cheliceral setae is longer and the tip of the proximal cheliceral seta does not reach insertion of the distal seta. (3) The distal cheliceral seta is inserted in the indistinct, vestigial, proximally open depression; in F.thaleri the distal cheliceral seta is inserted in the distinct, proximally open depression which is typical for the representatives of the genus Foveacheles . (4) Six genital setae on genital valve each and seven to eight pairs of aggenital setae flank the genital valves; in F. thaleri six to eight genital setae on genital valve each and ten pairs of aggenital setae in the genital region. (5) The rhagidial organ I is comprised of four rhagidial solenidia lying in tandem in confluent depressions and the stellate famulus (ε) inserted between first and second proximal rhagidial solenidia antiaxially; in F. thaleri four rhagidial solenidia are lying in separate and slightly oblique depressions and the stellate famulus (ε) is inserted laterad of first proximal rhagidial solenidion antiaxially.

Description

Adult female (two examined). Length of idiosoma 1080(1024–1136) µm. Ratio of leg I length to idiosomal length 1.33–1.45.

Gnathosoma . Subcapitulum broadly oval, subtriangular ( Fig. 38E); ratio of length to breadth 1.02–1.13; distal hypostomal lips with spiniform internal and serrate external malar processes; adoral setae nude, overlapping apex of subcapitulum; proximal subcapitular setae pubescent, external pair same length as internal pair. Dorsal surface of chelicera with deep saddle-shaped depression at level of bases of digits ( Fig. 38A,B); cheliceral digits long, dorsal surface of fixed digit with distinct narrow rim between insertions of cheliceral setae; fixed digit terminates in two cusps, smooth along masticatory surface and with distinct prebasal lateroventral fissure located distad of articulation of digits and proximad of insertion of proximal cheliceral seta; movable digit smooth along masticatory surface or only gently serrate along approximately distal third of masticatory surface ( Fig. 38B). Chelicera with two setae; proximal seta inserted distad of articulation of movable digit; tip of proximal seta reaching insertion of distal seta; tip of distal seta overlaps apex of fixed digit. Length of chelicera 270–274 µm, dorsoventral width 105–112 µm, length of movable digit 105–115 µm, length of proximal and distal cheliceral setae 30–35 and 53–56 µm, respectively, distance between their insertions 33 µm. Ratios: cheliceral length to dorsoventral width 2.41–2.59, length of movable digit to length of chelicera 0.39–0.42, length of movable digit to dorsoventral width of chelicera 0.94–1.09. Palpal tarsus same length as femorogenu ( Fig. 38F), ratio of length to width of tarsus 3.07–3.23. Palpal tarsus with small apical tubercle and thirteen pubescent setae longer than tarsus. Length of palpal trochanter, femorogenu, tibia and tarsus 46–49, 135–145, 69–79 and 138–142 µm, respectively. Number of setae and solenidia (in brackets) on palpal trochanter, femorogenu, tibia and tarsus 0-2-3-13(1), respectively; tarsal solenidion spiniform, erect.

Prodorsum. Naso well-developed, with pair of internal vertical setae v 1. Bothridial setae sc 1 filiform, finely pubescent, their tips reach to insertions of opisthosomal c 1 setae. Length of setae: v 1 66–76, v 2 99, sc 1 198, sc 2 211–222 µm.

Opisthosomal dorsum and anal region. Cupules ia positioned at level and slightly proximad of insertions of opisthosomal setae c 2; im lateral and just anterior to setae e 1; ip laterally between setae e 1 and f 1; ih ventrolaterally at level of insertions of adanal setae ad 1 ( Fig. 37). Setae c 1, d 1 reach almost to insertions of successive setae e 1; e 1 reach about half of distance to insertion of successive setae f 1; f 1 reach almost to insertions of h 1. Length of setae: c 1 99, c 2 torn off, d 1 99, e 1 102, f 1 112, f 2 66, h 1 165, h 2 79, ps 1 129, ps 2 86, ps 3 79, ad 1 83–85 µm.

Podosoma. Coxae I, II, III, IV with 3-1-6-3 finely pubescent setae, respectively.

Genital region. Genital valves each with six finely pubescent genital setae (g) of similar length, about 46– 56 µm, arranged evenly along medial edge of valve ( Fig. 37). Neotrichy in genital region: seven to eight pairs of aggenital setae (ag) of similar length about 82–86 µm flank genital valves. Length of genital valves 148– 155 µm.

Legs. Leg I 1488 –1520 µm long, about 1.33–1.45 as long as idiosoma. Empodia of all legs setulose, slightly overlapping claws; claws each with small clawlet ventrobasally. Number of setae and solenidia (solenidia and famulus (ε) bracketed), respectively, on legs I-II-III-IV (Figs 39,40): trochanters 1-1-2-2, basifemora + telofemora 5+5-6+5-4+4-4+4, genua 11(1)-8(1)-6(1)-6, tibiae 11(2)-8(2)-7(2)-6, tarsi 19(4+ε)- 16(3+ε)-14-14. Genua I and II each with one erect spiniform distoventral solenidion (σ); genu III with one small spiniform lateromedial solenidion. Tibia I with one erect spiniform dorsoproximal solenidion (Φ), and one dorsodistal rhagidial solenidion ( Fig. 38G); tibia II with one spiniform erect dorsoproximal solenidion, and one lanceolate dorsodistal solenidion recessed in deep pit with small surface pore ( Fig. 38H); tibia III with two erect spiniform lateroproximal solenidia arranged in tandem; solenidion on tibia IV absent. Tarsus I slen- der, its tip slightly tapers in lateral view ( Fig. 39C), ratio length to width 7.0, with four rhagidial solenidia (ω) lying in tandem in confluent depressions dorsodistally; stellate famulus (ε) between first and second proximal rhagidial solenidia antiaxially ( Fig. 38C); tarsus II with three rhagidial solenidia lying in tandem in confluent depressions and small spiniform famulus (ε) subtending proximal rhagidial solenidion ( Fig. 38D).

Remarks

The differential diagnosis of the newly described species T. subterranea n. sp. is based, among others, on comparison between T. subterranea n. sp., and the morphologically very similar species F. thaleri n. sp. which has not been previously described (see below).

Foveacheles thaleri n. sp. is an epigean and hypolithic in Austria, Greece and Cyprus where it lives under stones in moist forested and mountain habitats (Barbara Knoflach-Thaler, pers. comm.). Traegaardhia subterranea n. sp. inhabits a cave (caves?) in northeastern Italy. Their interspecific phylogenetic relations might be a subject of the adaptive shift hypothesis (see, for example, Culver & Pipan 2009) that admits the contemporary parallel existence of the both living ancestral F. thaleri n. sp. and the parapatrically derived T. subterranea n. sp. However, this tentative assumption awaits genetic analysis. In T. subterranea as well as in the epigean F. thaleri no troglomorphisms were distinguished.

Key to adults of the genus Traegaardhia

1 Rhagidial organ I comprised of five rhagidial solenidia arranged in tandem; masticatory surface of cheliceral fixed digit with two large subapical cusps. Italy, northeastern Prealps, Hills of Conegliano, troglobiont ...... T. nasuta n. sp.

- Rhagidial organ I comprised of three or four rhagidial solenidia; masticatory surface of cheliceral fixed digit smooth.......................................................................................................................................................................................2

2 Rhagidial organ I comprised of three rhagidial solenidia lying in tandem; France, Ariège, Saint-Girons, Cassis, Maritime Alps; Croatia, Krivosije, troglobiont. ................................................................. T. dalmatina ( Willmann, 1939)

- Rhagidial organ I comprised of four rhagidial solenidia..............................................................................................3

3 Rhagidial solenidia in rhagidial organ I short, i.e., maximally as long as diameter of tarsus at site of insertion (see in dorsal aspect), and arranged either in tandem axially or in oblique depressions.........................................................4

- Rhagidial solenidia in rhagidial organ I strikingly long, slender, i.e., much longer than diameter of tarsus at site of insertion, and arranged in separate oblique or nearly parallel depressions...................................................................7

4 Rhagidial solenidia in rhagidial organ I arranged in tandem in confluent depressions, stellate famulus (ε) inserted between first and second rhagidial solenidia. Italy, northeastern Prealps, Lessinian Mts, troglophile (?) ..................... ....................................................................................................................................................... T. subterranea n. sp.

- Rhagidial solenidia in rhagidial organ I in separate oblique depressions, stellate famulus (ε) between first and second proximal rhagidial solenidia or subtending second proximal rhagidial solenidion......................................................5

5 Spiniform solenidia on tibiae I and II dorsodistal. Italy, northeastern Prealps, Monti Berici Mts , in the mesovoid shallow substratum, and in caves in Sardinia, troglobiont (?) ................................................... T. distosolenidia n. sp .

- Spiniform solenidia on tibiae I and II dorsoproximal, spiniform famulus (ε) in rhagidial organ II between first and second proximal solenidia antiaxially, or subtending proximal solenidion.................................................................6

6 Spiniform famulus (ε) in rhagidial organ II between first and second proximal solenidia laterally, antiaxially; neotrichy of aggenital setae. U.S.A., Ozark Plateaus, troglobiont (?) .................................................. T. similis n. sp.

- Spiniform famulus (ε) in rhagidial organ II subtending proximal solenidion; no neotrichy in genital region, i.e., five pairs of aggenital setae flank genital valves. Italy, northeastern Prealps, Euganean Hills and Lessinian Mts, in the mesovoid shallow substratum .............................................................................................................. T. gracilis n. sp.

7 Proximal cheliceral seta inserted distad of articulation of cheliceral digits; solenidion on tibia I recumbent in longitu- dinal surface depression, resembling rhagidial solenidion; small solenidion on palpal tarsus recumbent. Italy, northeastern Prealps, troglobiont.......................... ................................................................................ T. cavernarum n. sp.

- Proximal cheliceral seta inserted at level of articulation of cheliceral digits; solenidion on tibia I spiniform, erect; solenidion on palpal tarsus spiniform, erect..................................................................................................................8

8 Coxae I, II, III, IV with 3-1-6-4 setae; rhagidial organ II comprised of four long, slender rhagidial solenidia in confluent depressions; masticatory surface of fixed cheliceral digit with tiny spiculate thorn at articulation of fixed and movable digit (as seen in lateral aspect). U.S.A., Ozark Plateaus, Interior Low Plateau, troglobiont ........................... ........................................................................................................................................ T. holsingeri ( Zacharda, 1980)

- Coxae I, II, III, IV with 3-1-5-3 or 3-1-6-3 setae; rhagidial organ II comprised of three rhagidial solenidia, no tiny spiculate thorn on masticatory surface of fixed cheliceral digit at articulation of fixed and movable digit.................9

9 Length of idiosoma 1280-1300 µm; stellate famulus (ε) in rhagidial organ I subtending second proximal rhagidial solenidion; three long, slender rhagidial solenidia in rhagidial organ II in tandem in confluent depressions. Italy, northeastern Prealps, Lessinian Mts, troglobiont......................................................... T. vicenzaensis Zacharda, 1994

- Length of idiosoma 750-930 µm; stellate famulus (ε) in rhagidial organ I inserted between second and third proximal rhagidial solenidia or laterad of second proximal rhagidial solenidion antiaxially; three long, slender rhagidial solenidia in rhagidial organ II in separate oblique depressions..................................................................................10

10 Rhagidial solenidia in rhagidial organ I oblique; stellate famulus (ε) in rhagidial organ I inserted between second and third proximal rhagidial solenidia; distal cheliceral seta inserted about in middle length of cheliceral fixed digit; spiniform solenidion on tibia I lateroventral, mediodistal, spiniform solenidion on tibia II dorsoproximal. Northeastern Italy, Stubai Alps, Monte Cavallo (Rosskopf) mountain range, troglobiont............................. T. cavernicola n. sp.

- Rhagidial solenidia in rhagidial organ I almost parallel; stellate famulus (ε) in rhagidial organ I subtends second proximal rhagidial solenidion; distal cheliceral seta inserted distally at about one third length of the fixed digit; solenidia on tibiae I and II dorsodistal, recumbent, resembling small rhagidial solenidia. U.S.A., Appalachians, troglobiont .................................................................................................................... T. paralleloseta ( Zacharda, 1985)