Roncocreagris borgesi Zaragoza & Reboleira

Reboleira, Ana Sofia P. S., Zaragoza, Juan A., Gonçalves, Fernando & Oromí, Pedro, 2013, On hypogean Roncocreagris (Arachnida: Pseudoscorpiones: Neobisiidae) from Portugal, with descriptions of three new species, Zootaxa 3670 (2), pp. 283-299 : 289-291

Roncocreagris borgesi Zaragoza & Reboleira sp. nov.

( Figs 13–22 )

Type material. Holotype: 3, Portugal, Sicó Massif, Santiago da Guarda, District of Leiria, Gruta da Cerâmica (39º55ʹ36.57ʺN, 8º31ʹ0 3.63ʺW; 355 m. a.s.l), 28.XI.2009, lgt. A.S.P.S. Reboleira ( DEUA coll.).

Etymology. The species is dedicated to the Portuguese biologist Professor Paulo Borges, who has greatly contributed to our knowledge of the hypogean fauna of the Azores.

Diagnosis. No eyes or eye-spots. Moderately troglomorphic. Carapace with 20 setae, 6 on the posterior margin. Tergite I with 6 setae. Male cheliceral galea short and simple. Pedipalp: femur ratio about 6.0, femur as long as the movable finger; chela+ length/breadth ratio about 5.0; chelal hand widest proximad of middle, ratio movable finger/hand+ 1.4; trichobothium ist close to the middle of the finger, ratio ib–ist / ist–it 1.5, ratio isb–ist / ib– isb 1.5.

Description. Medium-sized pseudoscorpion. Opisthosoma elongate, moderate troglomorphic adaptations. Opisthosoma and legs yellowish. Carapace, chelicerae and pedipalps reddish brown.

Carapace longer than broad ( Fig. 13 ). Without eyes or eye-spots. Anterior margin moderately prominent medially, epistome blunt and almost indistinguishable, with some tiny denticles not exceeding the anterior margin ( Fig. 14 ). Chaetotaxy: 20 setae, formula 4:4:6:6. Five microlyrifissures on ocular zone, two between median and posterior zones.

Coxal area. Manducatory process with 3 setae. Anterior process of coxa I with simple tooth shape, long and apically pointed; medial process straight with a few denticles ( Fig. 15 ). Pedipalpal coxa with 7 setae, pedal coxa I with 6, II: 3–4, III: 3–4, IV: 6.

Tergal chaetotaxy I–X: 6:7:9:9:9:11:11:10:10:9, most hairs lacking. Male genital area with 10 long setae on sternite II; sternite III with 10 setae, 4 of them along posterior margin of genital opening. Sternal chaetotaxy IV–X: 8:11:11:13:11:11:11; sternites VI and VII with 1 and 2 discal setae respectively (included in sternal formula); discal setae glandular, with visible duct. Segment XI 9 setae. Chaetotaxy of stigmata of sternites III and IV could not be checked due to partial contraction of opisthosoma. Anal cone with two dorsal and two ventral setae.

Chelicerae ( Figs 16–17 ). Palm with 6 setae; subgaleal seta 0.65 from base of movable finger. Galea short (length 0.03 mm), pointed and simple. Fixed finger with 6 small, blunt, distal denticles, resembling protuberances, and 10 normal teeth, 4 basal ones larger than the others; movable finger with 17 teeth, one large and blunt subdistal tooth, the others medium or small, dental row ending just proximad of subgaleal seta. Rallum with 8 blades, all unilaterally pinnate on anterior face, the basal one about half length of others. Serrula exterior with 31 blades, serrula interior 25 blades.

Pedipalps ( Figs 18–20 ). Trochanter, femur, distal third of the patella and the hand at base of the fingers with low granulation, more pronounced on paraxial faces. Lyrifissures as in Figs 18–20 . Femur with one tiny tubercle distad of middle of antiaxial face, one distal glandular pore present. Patella with one micropore at base of pedicel. Chelal hand oval shaped in dorsal view, maximum width proximad of middle; pedicel bears one dorsal micropore; antiaxial face, close to finger base, bears an irregular row of 4 glandular pores. Fixed finger with 93 teeth, most of them apically cusped, dental row reaching up to level of trichobothrium esb; nodus ramosus short, at level of 4th distal tooth; trichobothrium it proximad of et, distinctly closer to est than to et; trichobothrium ist closer to base of finger than to apex; distance between trichobothria ib and ist 1.5 times longer than that between ist and it; distance between trichobothria isb and ist 1.5 times longer than that between isb and ib. Chelal microsetae pattern with all groups present, extending distad of trichobothrium isb, Em 3–4, Mm 3, Im 1. Movable finger with 85 teeth, most of them apically cusped, dental row shorter than on fixed finger, ending distad of trichobothrium b; distance between trichobothria sb and st 1.2 times longer than that between sb and b. One sensillum near tip of both fingers; diploid sensillum pc not raised, close to dental margin, level with trichobothrium sb.

Legs. Claws of legs I and IV with a tiny dorsal tooth proximad of middle ( Fig. 21 ), subterminal setae with three rami ( Fig. 22 ). Leg IV tibia TS 0.44, basitarsus TS 0.22, telotarsus TS 0.24.

Measurements and ratios. Body 2.1. Carapace 0.85/0.64 (1.3). Chelicera: palm 0.49/0.24 (2.0), movable finger 0.33. Pedipalp: trochanter 0.66/0.19 (3.5); femur 1.15/0.19 (6.1); patella 1.06/0.23 (4.6), pedicel 0.29, club 0.77/0.23 (3.4), ratio club/pedicel: 2.7; chela+ 1.98/0.39 (5.0), chela - 1.84/0.39 (4.7); hand+ 0.85 (2.2), hand - 0.71 (1.8); movable finger 1.16; ratio finger/hand+ 1.4; ratio chela+/carapace 2.3; femur/carapace 1.4; finger/femur 1.0; femur/patella 1.1; patella/ hand+ 1.2. Leg I: femur 0.57/0.11 (5.2); patella 0.41/0.12 (3.3); tibia 0.53/.009 (5.6); basitarsus 0.26/0.08 (3.5); telotarsus 0.40/0.06 (6.9); ratio femur/patella 1.4; telotarsus/basitarsus 1.5. Leg IV: both femoris contracted and not measurable, patella 0.51/0.22 (2.4); tibia 0.88/0.11 (8.2); basitarsus 0.33/0.09 (3.4); telotarsus 0.49/0.07 (5.1); ratio telotarsus/basitarsus 1.5.

Remarks. Among the species with 6 setae or more on posterior margin of carapace and tergite I, the new species shares with R. aurouxi Zaragoza, 2000 (from Cantabria, Spain) the simple shape of the cheliceral galea, although it should be noted that the types of the two species belong to different sexes (only the female is known for R. aurouxi ). Also, both species have relatively low ratios for pedipalpal femur and chela for hypogean species of the genus. However, they differ in the chelal movable finger/hand ratio, which is 1.4 in R. borgesi vs 1.7 in R. auroxi ; moreover the chelal finger length is almost equal than the femur in the new species, but distinctly longer in R. aurouxi .

Distribution and habitat. Only known from the type locality in Sicó massif, Roncocreagris borgesi sp. nov. was collected in the deepest galleries of Cerâmica Cave, where relative humidity is around 100% throughout the year and mean temperature at soil level is 15.3ºC. The presence of two hypogean pseudoscorpion species, R. blothroides and R. borgesi , in the same cave is infrequent but not unknown (e.g. Zaragoza 2007). Due to the moderate troglomorphism and scarce occurrence of R. borgesi in the cave, compared to R. blothroides , we suggest that this species might predominantly occur in the mesovoid shallow substratum, rather than in the cave itself.

Cerâmica Cave is the richest one of central Portugal in terms of known troglobiont fauna, harboring 10 caveadapted species: 3 pseudoscorpions, 1 spider, 1 millipede, 3 oniscidean woodlice, 1 dipluran and 1 beetle (Reboleira, 2012). Among the cave-adapted species, the pseudoscorpions R. blothroides , R. borgesi sp. nov. and Chthonius sp., the spider Lepthyphantes sp. and the rove-beetle Domene lusitanica Reboleira & Oromí, 2011 are macro- and micropredators, while a new species of chordeumatid millipede, the woodlice Porcellio cavernicolus Vandel, 1964 and two trichoniscids, together with the dipluran Podocampa cf. fragiloides Silvestri, 1932, play a detritivorous role in this subterranean ecosystem ( Reboleira et al. 2011a, 2011b). Other interesting troglophile species have stable populations in this biocoenosis, such as the gastropod Oxychilus draparnaldi (Beck, 1837) , the centipede Lithobius pilicornis Newport, 1844 and the ground beetle Trechus fulvus Dejean, 1831 .

Figures

FIGURES 13 – 22. Roncocreagris borgesi sp. nov., male holotype. 13. carapace; 14. anterior margin of carapace; 15. anterior and medial processes of left coxa I; 16. right chelicera; 17. partial view of fingers of right chelicera, showing galea; 18. left pedipalp minus chela, dorsal view; 19. left chela, dorsal view; 20. right chela, lateral view; 21. claw of right leg IV; 22. subterminal seta of right leg IV. Scale bars (in mm): 0.05 (Figs 14, 21, 22), 0.10 (Figs 15 – 17), 0.30 (Fig. 13), 0.50 (Figs 18 – 20).