Troglocheles lanai Zacharda, 2011

Zacharda, Miloslav, Isaia, Marco & Piva, Erminio, 2011, New troglobitic species of the genus Troglocheles (Acari: Prostigmata: Rhagidiidae) from caves in northern Italy and Austria, with a key to adult species of the genus, Journal of Natural History 45 (11 - 12), pp. 641-666 : 649-656

Troglocheles lanai Zacharda , sp. nov.

( Figures 6–9 )

Material examined

Holotype. Adult female, Italy, Piedmont, Cuneo, Valdieri (1214 Pi / CN), Vallone dell’Infernotto, Barôn Litrôn-Maissa 6 Cave , universal transverse mercator ( UTM) coordinates: 32 T 373117 4902365 (44 ◦ 15 ′ 47 ′′ N, 7 ◦ 24 ′ 37 ′′ E), 1050 m a.s.l., coll. E. Lana, 21 August 2004, deposited in the Museum of Biological Diversity , Ohio State University, Type No. OSAL007450 .

Paratypes. Deposited with the holotype; two adult females, same data as holotype , coll. E. Lana, 13 April 2003, OSAL007448 and OSAL007449 ; adult female, same data

A,B

as holotype, coll. M. Isaia and E. Lana, 3 December 2006, OSAL007447 ; adult male, same data as holotype, coll. M. Isaia and M. Paschetta, 14 May 2009, OSAL007446 ; adult female, Piedmont, Cuneo, Frabosa Soprana (108 Pi / CN), Valle Corsaglia, Grotta di Bossea Cave , UTM coordinates: 32 T 407464 4899559 (44 ◦ 14 ′ 34 ′′ N, 7 ◦ 50 ′ 27 ′′ E), 836 m a.s.l., coll. E. Lana, 23 September 2001, OSAL007445 ; adult female, Piedmont, Cuneo, Frabosa Soprana, (837 Pi / CN), Abisso Bacardi Cave , UTM 32 T 403600 4898640 (44 ◦ 14 ′ 04 ′′ N, 7 ◦ 47 ′ 35 ′′ E), coll. E. Lana, 14 May 1995, OSAL007444 ; additional material examined: adult male, Piedmont, Cuneo, Frabosa Soprana (108 Pi / CN), Valle Corsaglia, Grotta di Bossea Cave , coll. E. Lana, 26 December 1998 ; adult male, same data, coll. M. Isaia and M. Paschetta, 16.12.2009 ; three adult females and one adult male, Piedmont, Cuneo, Frabosa Soprana, (837 Pi / CN), Abisso Bacardi Cave , coll. E. Lana, 15 April 1997, deposited in collection of M. Zacharda ; adult female, Piedmont, Cuneo , Frabosa Soprana (108

F

Pi / CN ), Valle Corsaglia, Grotta di Bossea Cave , UTM coordinates: 32 T 407464 4899559 (44 ◦ 14 ′ 34 ′′ N, 7 ◦ 50 ′ 27 ′′ E), 836 m a.s.l., coll. E. Lana, 20 December 2009; one tritonymph, Piedmont, Cuneo, Valdieri (1214 Pi / CN), Vallone dell’Infernotto, Barôn Litrôn-Maissa 6 Cave , UTM coordinates: 32 T 373117 4902365 (44 ◦ 15 ′ 47 ′′ N, 7 ◦ 24 ′ 37 ′′ E), 1050 m a.s.l., coll. M. Isaia, 24 April 2010; the latter two specimens are deposited in the Natural Museum of Torino as the voucher specimens of the All Taxa Biodiversity Inventory and Monitoring Project of the European Distributed Institute of Taxonomy ( EDIT) .

Diagnosis

Rhagidial organ I comprises 12, 13 or 14 rhagidial solenidia lying symmetrically or asymmetrically, in separate oblique depressions; rhagidial organ II with four rhagidial solenidia lying in separate oblique depressions, and small spiniform famulus (ε) subtending proximal rhagidial solenidion. Tarsus III with two adjacent dorsodistal rhagidial solenidia lying in separate depressions axially, famulus absent. Spiniform solenidion on tibia I and II long, positioned dorsodistally just proximad of dorsodistal rhagidial or lanceolate solenidion, respectively. Tibia IV with one long spiniform dorsal medioproximal solenidion. Ratio of tarsus I length to dorsoventral width 6.25– 9.33; ratio of palpal tarsus length to width 4.23–5.25. Bothridial setae sc 1 slightly overlapping insertions of opisthosomal setae c 1. Movable digit of chelicera striated along proximal two-thirds of length – see in lateral aspect.

Description – adult females (10 examined)

Length of idiosoma 1056–1280 µm. Ratio of leg I length to idiosomal length 1.98–2.43.

Gnathosoma . Subcapitulum slenderly elongated, cylindrical, ratio of length to breadth 1.65–1.71; distal hypostomal lips with spiniform internal and serrate external malar processes; adoral setae nude and overlapping apex of subcapitulum, proximal subcapitular setae fine, pointed, pubescent, external pair slightly longer than internal pair ( Figure 7F ). Dorsal surface of chelicera with saddle-shaped depression above level of bases of digits; cheliceral digits strikingly long, slender; fixed digit terminates in two large cusps, smooth along masticatory surface and with small lateral vertical fissure at level of bases of digits ( Figure 7D ); movable digit smooth along masticatory surface and strikingly striated along proximal two-thirds (see in lateral aspect). Chelicera with two setae inserted distad of articulation of movable digit; tip of proximal seta almost reaching insertion of distal seta; tip of distal seta overlaps apex of fixed digit. Length of chelicera 320–429 µm, dorsoventral width 79–145 µm, length of movable digit 162–221 µm, length of proximal and distal cheliceral setae 23–33 and 66–86 µm, respectively, distance between their insertions 23–46 µm. Ratios: cheliceral length to dorsoventral width 2.86–4.05; length of movable digit to length of chelicera 0.50–0.53; length of movable digit to dorsoventral width of chelicera 1.50–2.05. Palpal tarsus shorter than femorogenu ( Figure 7E ), ratio of length to width of tarsus 4.16–5.25. Length of palpal trochanter, femorogenu, tibia and tarsus 59–66, 247–264, 76-102 and 181–208 µm, respectively. Number of setae and solenidia (in brackets) on palpal trochanter, femorogenu, tibia and tarsus 0-2-3-10(1), respectively; tarsal solenidion long, spiniform, erect.

Prodorsum. Naso well-developed ( Figure 7H ), with pair of long internal vertical setae v 1. Bothridial setae sc 1 filiform, finely pubescent, slightly overlapping insertions of opisthosomal setae c 1. Length of setae: v 1 99–115, v 2 72–79, sc 1 138–188, sc 2 155–188 µm.

Opisthosomal dorsum and anal region. Cupules ia positioned proximad of insertions of setae c 2, im laterad and slightly distad of insertions of e 1, ip laterad and slightly distad of insertions of f 1, ih positioned laterodistad of insertions of adanal setae ad 1 ( Figure 6A ). Length of setae: c 1 79–132, c 2 168–198, d 1 92–122, e 1 92–115, f 1 145–175, f 2 63–105, h 1 165–208, h 2 99–138, ps 1 138–175, ps 2 89–115, ps 3 49–69, ad 1 60–67 µm.

Podosoma. Coxae I-II-III-IV with 3-1-5-3, exceptionally 4-1-5-3 or 4 / 3-1-5-3 finely pubescent setae, respectively ( Figure 6B ).

Genital region. Genital valves each with five finely pubescent genital setae (g) of similar length, about 26–46 µm, arranged evenly along medial edge of valve. Five pairs of pointed aggenital setae (ag) of similar length, about 59–86 µm. Length of genital valves 115–165 µm.

Legs. Leg I 2224 –2720 µm long, about 1.98–2.43 times as long as idiosoma. Empodia of all legs setulose, longer than claws, no ventrobasal clawlets on claws. Trochanter I strikingly enlarged. Tarsi II, III, IV each with oar-like subapical setae typical of Troglocheles ( Figure 9C ). Number of setae and solenidia (solenidia and famulus (ε) bracketed), respectively, on legs I-II-III-IV ( Figures 8 , 9 ): trochanters 1-1-2-2, exceptionally three setae on trochanter III; basifemora + telofemora 5+5-6+5-4+4-3+4; genua 17(1)-9(1)-9(1)-7; tibiae 12(2)-8(2)-7(2)-6(1); tarsi 18(13 or 14+ ε)-17(4+ ε)- 16-15. Spiniform solenidia on leg segments conspicuously long. Genua I and II each with one erect spiniform distoventral solenidion (σ); genu III with one long spiniform dorso-mediodistal solenidion ( Figure 9A ). Tibia I with one erect spiniform dorsodistal solenidion (Φ) positioned just proximad of dorsodistal rhagidial solenidion ( Figure 8C,D ); tibia II with one spiniform erect dorsodistal solenidion positioned just proximad of dorsodistal lanceolate solenidion recessed in deep pit with broadly open surface pore ( Figure 8F,G ); tibia III with two adjacent erect spiniform dorsomedial solenidia ( Figure 9A ); tibia IV with one erect spiniform dorsoproximal solenidion ( Figure 9C ). Tarsus I slender, its tip slightly tapers in lateral view, ratio length to width 8.66–9.33, with 12–14 rhagidial solenidia (ω) lying obliquely in separate depressions dorsodistally ( Figure 7A,B ), stellate famulus (ε) inserted between first and second proximal rhagidial solenidia antiaxially; tarsus II with four rhagidial solenidia lying in separate oblique depressions, and small spiniform famulus (ε) subtending proximal rhagidial solenidion antiaxially ( Figure 7C ), tarsus III with two adjacent solenidia arranged in separate depressions axially, famulus absent ( Figure 9B ).

Description – adult male (four examined)

A club-shaped sperm sac (ss) showing through the opisthosomal tegument; genital valves each with five and six setae asymmetrically; otherwise as in female ( Figure 6B ).

Affinities

Among other representatives of the genus Troglocheles , T. lanai sp. nov. possesses the most expressed adaptive apomorphic troglomorphisms, i.e. 12–14 rhagidial solenidia in the rhagidial organ I (both tarsi examined in the same specimen, i.e. the number of solenidia in the rhagidial organ I may be asymmetrical), and two rhagidial solenidia on tarsus III, i.e. the rhagidial organ III. Troglocheles lanai sp. nov. belongs to the vornatscheri species group because its coxal formula is 3-1-5-3, the distance between insertions of the cheliceral setae on the fixed digits is almost the same as the length of the proximal cheliceral seta, and the spiniform solenidion on tibia I is positioned dorsodistally (cf. Zacharda 2000, Table 1: 470). However, T. lanai sp. nov. differs from T. vornatscheri in the following characteristics: (1) The number of rhagidial solenidia in rhagidial organ I is 12, 13 or 14 (examine both tarsi I); in T. vornatscheri the rhagidial organ I comprises eight rhagidial solenidia. (2) Two adjacent rhagidial solenidia are on tarsus III (rhagidial organ III); in T. vornatscheri no rhagidial solenidia on tarsus III. (3) The position of the spiniform solenidion on tibia II is dorsodistal, just behind the dorsodistal lanceolate solenidion; in T. vornatscheri this solenidion is laterodorsal, proximal. (4) The position of the spiniform solenidion on genu III is dorsodistal; in T. vornatscheri it is lateromedial.

Etymology

The epithet lanai was used in honour of Enrico Lana, the Italian biospeleologist, collector and photographer of the cave invertebrates in the region of Piedmont ( Lana 2001). He first discovered this new troglobitic species in the Barôn Litrôn cave (locus typicus). Feminine gender.

Remarks

Hitherto the rhagidial organ III has been known only in the troglomorphic Flabellorhagidia pecki Elliott, 1976 from the Boy Scout Cave, Craters of the Moon National Monument, Butte Co., ID, USA ( Elliott 1976). The chelicerae of this rhagidiid mite are strikingly similar to these in the Troglocheles species. However, in F. pecki the tarsi II, III and IV are with the normal flagelliform iteral setae, i.e. not the oar-like iteral setae that are typical of the Troglocheles species.

More detailed information on the Piedmontese caves can be found elsewhere ( Peano and Morisi 1982; Lana 2001; Gruppo Speleologico Alpi Marittime 2005).

Figures

Figure 6. Troglocheles lanai sp. nov., adult male; (A) dorsum; (B) venter (for setal notation see Description).

Figure 7. Troglocheles lanai sp. nov., adult female; (A,B) rhagidial organ I; (C) rhagidial organ II; (D) chelicera, lateral aspect; (E) palpus, lateral aspect; (F) subcapitulum, ventral aspect; (G) anomalous neotrichy on trochanter III; (H) elongated naso.

Figure 8. Troglocheles lanai sp. nov., adult female, setal arrangement on legs, lateral aspect; (A) leg I – genu, tibia, tarsus; (B) leg I – trochanter, basi- and telofemur; (C,D) variations in positions of dorsodistal rhagidial Φ1 and spiniform Φ2 solenidia on tibia I, dorsal aspect; (E) leg II; (F,G) variations in positions of dorsodistal lanceolate Φ1 and spiniform Φ2 solenidia on tibia II, dorsal and lateral aspect, respectively; (ω, Φ, σ and ε designations for solenidia on tarsus, tibia, genu and for famulus, respectively).

Figure 9. Troglocheles lanai sp. nov., adult female, setal arrangement on legs, lateral aspect; (A) leg III, (B) apex of tarsus III with oar-like iteral (it) setae and two rhagidial solenidia, lateral aspect; (C) leg IV (ω, Φ, σ designations for solenidia on tarsus, tibia, genu, respectively).